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										 |  |  | #ifndef _ASM_X86_PERCPU_H
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							|  |  |  | #define _ASM_X86_PERCPU_H
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										 |  |  | #ifdef CONFIG_X86_64
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										 |  |  | #define __percpu_seg		gs
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							|  |  |  | #define __percpu_mov_op		movq
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										 |  |  | #else
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										 |  |  | #define __percpu_seg		fs
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							|  |  |  | #define __percpu_mov_op		movl
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										 |  |  | #endif
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										 |  |  | 
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							|  |  |  | #ifdef __ASSEMBLY__
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							|  |  |  | 
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							|  |  |  | /*
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							|  |  |  |  * PER_CPU finds an address of a per-cpu variable. | 
					
						
							|  |  |  |  * | 
					
						
							|  |  |  |  * Args: | 
					
						
							|  |  |  |  *    var - variable name | 
					
						
							|  |  |  |  *    reg - 32bit register | 
					
						
							|  |  |  |  * | 
					
						
							|  |  |  |  * The resulting address is stored in the "reg" argument. | 
					
						
							|  |  |  |  * | 
					
						
							|  |  |  |  * Example: | 
					
						
							|  |  |  |  *    PER_CPU(cpu_gdt_descr, %ebx) | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | #ifdef CONFIG_SMP
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										 |  |  | #define PER_CPU(var, reg)						\
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										 |  |  | 	__percpu_mov_op %__percpu_seg:this_cpu_off, reg;		\ | 
					
						
							|  |  |  | 	lea var(reg), reg | 
					
						
							|  |  |  | #define PER_CPU_VAR(var)	%__percpu_seg:var
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										 |  |  | #else /* ! SMP */
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										 |  |  | #define PER_CPU(var, reg)	__percpu_mov_op $var, reg
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							|  |  |  | #define PER_CPU_VAR(var)	var
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										 |  |  | #endif	/* SMP */
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										 |  |  | #ifdef CONFIG_X86_64_SMP
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							|  |  |  | #define INIT_PER_CPU_VAR(var)  init_per_cpu__##var
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							|  |  |  | #else
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										 |  |  | #define INIT_PER_CPU_VAR(var)  var
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										 |  |  | #endif
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										 |  |  | #else /* ...!ASSEMBLY */
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										 |  |  | #include <linux/kernel.h>
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										 |  |  | #include <linux/stringify.h>
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										 |  |  | #ifdef CONFIG_SMP
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										 |  |  | #define __percpu_prefix		"%%"__stringify(__percpu_seg)":"
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										 |  |  | #define __my_cpu_offset		this_cpu_read(this_cpu_off)
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										 |  |  | 
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							|  |  |  | /*
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							|  |  |  |  * Compared to the generic __my_cpu_offset version, the following | 
					
						
							|  |  |  |  * saves one instruction and avoids clobbering a temp register. | 
					
						
							|  |  |  |  */ | 
					
						
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										 |  |  | #define arch_raw_cpu_ptr(ptr)				\
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										 |  |  | ({							\ | 
					
						
							|  |  |  | 	unsigned long tcp_ptr__;			\ | 
					
						
							|  |  |  | 	asm volatile("add " __percpu_arg(1) ", %0"	\ | 
					
						
							|  |  |  | 		     : "=r" (tcp_ptr__)			\ | 
					
						
							|  |  |  | 		     : "m" (this_cpu_off), "0" (ptr));	\ | 
					
						
							|  |  |  | 	(typeof(*(ptr)) __kernel __force *)tcp_ptr__;	\ | 
					
						
							|  |  |  | }) | 
					
						
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										 |  |  | #else
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										 |  |  | #define __percpu_prefix		""
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										 |  |  | #endif
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										 |  |  | #define __percpu_arg(x)		__percpu_prefix "%" #x
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										 |  |  | /*
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							|  |  |  |  * Initialized pointers to per-cpu variables needed for the boot | 
					
						
							|  |  |  |  * processor need to use these macros to get the proper address | 
					
						
							|  |  |  |  * offset from __per_cpu_load on SMP. | 
					
						
							|  |  |  |  * | 
					
						
							|  |  |  |  * There also must be an entry in vmlinux_64.lds.S | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | #define DECLARE_INIT_PER_CPU(var) \
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										 |  |  |        extern typeof(var) init_per_cpu_var(var) | 
					
						
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							|  |  |  | #ifdef CONFIG_X86_64_SMP
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							|  |  |  | #define init_per_cpu_var(var)  init_per_cpu__##var
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							|  |  |  | #else
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										 |  |  | #define init_per_cpu_var(var)  var
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										 |  |  | #endif
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										 |  |  | /* For arch-specific code, we can use direct single-insn ops (they
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							|  |  |  |  * don't give an lvalue though). */ | 
					
						
							|  |  |  | extern void __bad_percpu_size(void); | 
					
						
							|  |  |  | 
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										 |  |  | #define percpu_to_op(op, var, val)			\
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							|  |  |  | do {							\ | 
					
						
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										 |  |  | 	typedef typeof(var) pto_T__;			\ | 
					
						
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										 |  |  | 	if (0) {					\ | 
					
						
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										 |  |  | 		pto_T__ pto_tmp__;			\ | 
					
						
							|  |  |  | 		pto_tmp__ = (val);			\ | 
					
						
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										 |  |  | 		(void)pto_tmp__;			\ | 
					
						
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										 |  |  | 	}						\ | 
					
						
							|  |  |  | 	switch (sizeof(var)) {				\ | 
					
						
							|  |  |  | 	case 1:						\ | 
					
						
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										 |  |  | 		asm(op "b %1,"__percpu_arg(0)		\ | 
					
						
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										 |  |  | 		    : "+m" (var)			\ | 
					
						
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										 |  |  | 		    : "qi" ((pto_T__)(val)));		\ | 
					
						
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										 |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 2:						\ | 
					
						
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										 |  |  | 		asm(op "w %1,"__percpu_arg(0)		\ | 
					
						
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										 |  |  | 		    : "+m" (var)			\ | 
					
						
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										 |  |  | 		    : "ri" ((pto_T__)(val)));		\ | 
					
						
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										 |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 4:						\ | 
					
						
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										 |  |  | 		asm(op "l %1,"__percpu_arg(0)		\ | 
					
						
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										 |  |  | 		    : "+m" (var)			\ | 
					
						
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										 |  |  | 		    : "ri" ((pto_T__)(val)));		\ | 
					
						
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										 |  |  | 		break;					\ | 
					
						
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										 |  |  | 	case 8:						\ | 
					
						
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										 |  |  | 		asm(op "q %1,"__percpu_arg(0)		\ | 
					
						
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										 |  |  | 		    : "+m" (var)			\ | 
					
						
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										 |  |  | 		    : "re" ((pto_T__)(val)));		\ | 
					
						
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										 |  |  | 		break;					\ | 
					
						
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										 |  |  | 	default: __bad_percpu_size();			\ | 
					
						
							|  |  |  | 	}						\ | 
					
						
							|  |  |  | } while (0) | 
					
						
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											2010-01-05 15:34:50 +09:00
										 |  |  | /*
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							|  |  |  |  * Generate a percpu add to memory instruction and optimize code | 
					
						
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										 |  |  |  * if one is added or subtracted. | 
					
						
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										 |  |  |  */ | 
					
						
							|  |  |  | #define percpu_add_op(var, val)						\
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							|  |  |  | do {									\ | 
					
						
							|  |  |  | 	typedef typeof(var) pao_T__;					\ | 
					
						
							|  |  |  | 	const int pao_ID__ = (__builtin_constant_p(val) &&		\ | 
					
						
							| 
									
										
											  
											
												percpu: fix this_cpu_sub() subtrahend casting for unsigneds
this_cpu_sub() is implemented as negation and addition.
This patch casts the adjustment to the counter type before negation to
sign extend the adjustment.  This helps in cases where the counter type
is wider than an unsigned adjustment.  An alternative to this patch is
to declare such operations unsupported, but it seemed useful to avoid
surprises.
This patch specifically helps the following example:
  unsigned int delta = 1
  preempt_disable()
  this_cpu_write(long_counter, 0)
  this_cpu_sub(long_counter, delta)
  preempt_enable()
Before this change long_counter on a 64 bit machine ends with value
0xffffffff, rather than 0xffffffffffffffff.  This is because
this_cpu_sub(pcp, delta) boils down to this_cpu_add(pcp, -delta),
which is basically:
  long_counter = 0 + 0xffffffff
Also apply the same cast to:
  __this_cpu_sub()
  __this_cpu_sub_return()
  this_cpu_sub_return()
All percpu_test.ko passes, especially the following cases which
previously failed:
  l -= ui_one;
  __this_cpu_sub(long_counter, ui_one);
  CHECK(l, long_counter, -1);
  l -= ui_one;
  this_cpu_sub(long_counter, ui_one);
  CHECK(l, long_counter, -1);
  CHECK(l, long_counter, 0xffffffffffffffff);
  ul -= ui_one;
  __this_cpu_sub(ulong_counter, ui_one);
  CHECK(ul, ulong_counter, -1);
  CHECK(ul, ulong_counter, 0xffffffffffffffff);
  ul = this_cpu_sub_return(ulong_counter, ui_one);
  CHECK(ul, ulong_counter, 2);
  ul = __this_cpu_sub_return(ulong_counter, ui_one);
  CHECK(ul, ulong_counter, 1);
Signed-off-by: Greg Thelen <gthelen@google.com>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
											
										 
											2013-10-30 13:56:20 -07:00
										 |  |  | 			      ((val) == 1 || (val) == -1)) ?		\ | 
					
						
							|  |  |  | 				(int)(val) : 0;				\ | 
					
						
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										 |  |  | 	if (0) {							\ | 
					
						
							|  |  |  | 		pao_T__ pao_tmp__;					\ | 
					
						
							|  |  |  | 		pao_tmp__ = (val);					\ | 
					
						
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										 |  |  | 		(void)pao_tmp__;					\ | 
					
						
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										 |  |  | 	}								\ | 
					
						
							|  |  |  | 	switch (sizeof(var)) {						\ | 
					
						
							|  |  |  | 	case 1:								\ | 
					
						
							|  |  |  | 		if (pao_ID__ == 1)					\ | 
					
						
							|  |  |  | 			asm("incb "__percpu_arg(0) : "+m" (var));	\ | 
					
						
							|  |  |  | 		else if (pao_ID__ == -1)				\ | 
					
						
							|  |  |  | 			asm("decb "__percpu_arg(0) : "+m" (var));	\ | 
					
						
							|  |  |  | 		else							\ | 
					
						
							|  |  |  | 			asm("addb %1, "__percpu_arg(0)			\ | 
					
						
							|  |  |  | 			    : "+m" (var)				\ | 
					
						
							|  |  |  | 			    : "qi" ((pao_T__)(val)));			\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 2:								\ | 
					
						
							|  |  |  | 		if (pao_ID__ == 1)					\ | 
					
						
							|  |  |  | 			asm("incw "__percpu_arg(0) : "+m" (var));	\ | 
					
						
							|  |  |  | 		else if (pao_ID__ == -1)				\ | 
					
						
							|  |  |  | 			asm("decw "__percpu_arg(0) : "+m" (var));	\ | 
					
						
							|  |  |  | 		else							\ | 
					
						
							|  |  |  | 			asm("addw %1, "__percpu_arg(0)			\ | 
					
						
							|  |  |  | 			    : "+m" (var)				\ | 
					
						
							|  |  |  | 			    : "ri" ((pao_T__)(val)));			\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 4:								\ | 
					
						
							|  |  |  | 		if (pao_ID__ == 1)					\ | 
					
						
							|  |  |  | 			asm("incl "__percpu_arg(0) : "+m" (var));	\ | 
					
						
							|  |  |  | 		else if (pao_ID__ == -1)				\ | 
					
						
							|  |  |  | 			asm("decl "__percpu_arg(0) : "+m" (var));	\ | 
					
						
							|  |  |  | 		else							\ | 
					
						
							|  |  |  | 			asm("addl %1, "__percpu_arg(0)			\ | 
					
						
							|  |  |  | 			    : "+m" (var)				\ | 
					
						
							|  |  |  | 			    : "ri" ((pao_T__)(val)));			\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 8:								\ | 
					
						
							|  |  |  | 		if (pao_ID__ == 1)					\ | 
					
						
							|  |  |  | 			asm("incq "__percpu_arg(0) : "+m" (var));	\ | 
					
						
							|  |  |  | 		else if (pao_ID__ == -1)				\ | 
					
						
							|  |  |  | 			asm("decq "__percpu_arg(0) : "+m" (var));	\ | 
					
						
							|  |  |  | 		else							\ | 
					
						
							|  |  |  | 			asm("addq %1, "__percpu_arg(0)			\ | 
					
						
							|  |  |  | 			    : "+m" (var)				\ | 
					
						
							|  |  |  | 			    : "re" ((pao_T__)(val)));			\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	default: __bad_percpu_size();					\ | 
					
						
							|  |  |  | 	}								\ | 
					
						
							|  |  |  | } while (0) | 
					
						
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										 |  |  | #define percpu_from_op(op, var)				\
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										 |  |  | ({							\ | 
					
						
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										 |  |  | 	typeof(var) pfo_ret__;				\ | 
					
						
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										 |  |  | 	switch (sizeof(var)) {				\ | 
					
						
							|  |  |  | 	case 1:						\ | 
					
						
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										 |  |  | 		asm(op "b "__percpu_arg(1)",%0"		\ | 
					
						
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										 |  |  | 		    : "=q" (pfo_ret__)			\ | 
					
						
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										 |  |  | 		    : "m" (var));			\ | 
					
						
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										 |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 2:						\ | 
					
						
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											2009-01-19 00:38:59 +09:00
										 |  |  | 		asm(op "w "__percpu_arg(1)",%0"		\ | 
					
						
							| 
									
										
										
										
											2009-10-29 22:34:12 +09:00
										 |  |  | 		    : "=r" (pfo_ret__)			\ | 
					
						
							| 
									
										
										
										
											2014-11-04 08:50:48 +00:00
										 |  |  | 		    : "m" (var));			\ | 
					
						
							| 
									
										
										
										
											2008-03-23 01:03:06 -07:00
										 |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 4:						\ | 
					
						
							| 
									
										
										
										
											2009-01-19 00:38:59 +09:00
										 |  |  | 		asm(op "l "__percpu_arg(1)",%0"		\ | 
					
						
							| 
									
										
										
										
											2009-10-29 22:34:12 +09:00
										 |  |  | 		    : "=r" (pfo_ret__)			\ | 
					
						
							| 
									
										
										
										
											2014-11-04 08:50:48 +00:00
										 |  |  | 		    : "m" (var));			\ | 
					
						
							| 
									
										
										
										
											2009-01-13 20:41:35 +09:00
										 |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 8:						\ | 
					
						
							| 
									
										
										
										
											2009-01-19 00:38:59 +09:00
										 |  |  | 		asm(op "q "__percpu_arg(1)",%0"		\ | 
					
						
							| 
									
										
										
										
											2009-10-29 22:34:12 +09:00
										 |  |  | 		    : "=r" (pfo_ret__)			\ | 
					
						
							| 
									
										
										
										
											2014-11-04 08:50:48 +00:00
										 |  |  | 		    : "m" (var));			\ | 
					
						
							|  |  |  | 		break;					\ | 
					
						
							|  |  |  | 	default: __bad_percpu_size();			\ | 
					
						
							|  |  |  | 	}						\ | 
					
						
							|  |  |  | 	pfo_ret__;					\ | 
					
						
							|  |  |  | }) | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | #define percpu_stable_op(op, var)			\
 | 
					
						
							|  |  |  | ({							\ | 
					
						
							|  |  |  | 	typeof(var) pfo_ret__;				\ | 
					
						
							|  |  |  | 	switch (sizeof(var)) {				\ | 
					
						
							|  |  |  | 	case 1:						\ | 
					
						
							|  |  |  | 		asm(op "b "__percpu_arg(P1)",%0"	\ | 
					
						
							|  |  |  | 		    : "=q" (pfo_ret__)			\ | 
					
						
							|  |  |  | 		    : "p" (&(var)));			\ | 
					
						
							|  |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 2:						\ | 
					
						
							|  |  |  | 		asm(op "w "__percpu_arg(P1)",%0"	\ | 
					
						
							|  |  |  | 		    : "=r" (pfo_ret__)			\ | 
					
						
							|  |  |  | 		    : "p" (&(var)));			\ | 
					
						
							|  |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 4:						\ | 
					
						
							|  |  |  | 		asm(op "l "__percpu_arg(P1)",%0"	\ | 
					
						
							|  |  |  | 		    : "=r" (pfo_ret__)			\ | 
					
						
							|  |  |  | 		    : "p" (&(var)));			\ | 
					
						
							|  |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 8:						\ | 
					
						
							|  |  |  | 		asm(op "q "__percpu_arg(P1)",%0"	\ | 
					
						
							|  |  |  | 		    : "=r" (pfo_ret__)			\ | 
					
						
							|  |  |  | 		    : "p" (&(var)));			\ | 
					
						
							| 
									
										
										
										
											2008-03-23 01:03:06 -07:00
										 |  |  | 		break;					\ | 
					
						
							|  |  |  | 	default: __bad_percpu_size();			\ | 
					
						
							|  |  |  | 	}						\ | 
					
						
							| 
									
										
										
										
											2009-10-29 22:34:12 +09:00
										 |  |  | 	pfo_ret__;					\ | 
					
						
							| 
									
										
										
										
											2008-03-23 01:03:06 -07:00
										 |  |  | }) | 
					
						
							| 
									
										
										
										
											2008-01-30 13:32:53 +01:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2010-04-21 15:21:51 +01:00
										 |  |  | #define percpu_unary_op(op, var)			\
 | 
					
						
							|  |  |  | ({							\ | 
					
						
							|  |  |  | 	switch (sizeof(var)) {				\ | 
					
						
							|  |  |  | 	case 1:						\ | 
					
						
							|  |  |  | 		asm(op "b "__percpu_arg(0)		\ | 
					
						
							|  |  |  | 		    : "+m" (var));			\ | 
					
						
							|  |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 2:						\ | 
					
						
							|  |  |  | 		asm(op "w "__percpu_arg(0)		\ | 
					
						
							|  |  |  | 		    : "+m" (var));			\ | 
					
						
							|  |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 4:						\ | 
					
						
							|  |  |  | 		asm(op "l "__percpu_arg(0)		\ | 
					
						
							|  |  |  | 		    : "+m" (var));			\ | 
					
						
							|  |  |  | 		break;					\ | 
					
						
							|  |  |  | 	case 8:						\ | 
					
						
							|  |  |  | 		asm(op "q "__percpu_arg(0)		\ | 
					
						
							|  |  |  | 		    : "+m" (var));			\ | 
					
						
							|  |  |  | 		break;					\ | 
					
						
							|  |  |  | 	default: __bad_percpu_size();			\ | 
					
						
							|  |  |  | 	}						\ | 
					
						
							|  |  |  | }) | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2010-12-17 15:47:04 +01:00
										 |  |  | /*
 | 
					
						
							|  |  |  |  * Add return operation | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | #define percpu_add_return_op(var, val)					\
 | 
					
						
							|  |  |  | ({									\ | 
					
						
							|  |  |  | 	typeof(var) paro_ret__ = val;					\ | 
					
						
							|  |  |  | 	switch (sizeof(var)) {						\ | 
					
						
							|  |  |  | 	case 1:								\ | 
					
						
							|  |  |  | 		asm("xaddb %0, "__percpu_arg(1)				\ | 
					
						
							|  |  |  | 			    : "+q" (paro_ret__), "+m" (var)		\ | 
					
						
							|  |  |  | 			    : : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 2:								\ | 
					
						
							|  |  |  | 		asm("xaddw %0, "__percpu_arg(1)				\ | 
					
						
							|  |  |  | 			    : "+r" (paro_ret__), "+m" (var)		\ | 
					
						
							|  |  |  | 			    : : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 4:								\ | 
					
						
							|  |  |  | 		asm("xaddl %0, "__percpu_arg(1)				\ | 
					
						
							|  |  |  | 			    : "+r" (paro_ret__), "+m" (var)		\ | 
					
						
							|  |  |  | 			    : : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 8:								\ | 
					
						
							|  |  |  | 		asm("xaddq %0, "__percpu_arg(1)				\ | 
					
						
							|  |  |  | 			    : "+re" (paro_ret__), "+m" (var)		\ | 
					
						
							|  |  |  | 			    : : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	default: __bad_percpu_size();					\ | 
					
						
							|  |  |  | 	}								\ | 
					
						
							|  |  |  | 	paro_ret__ += val;						\ | 
					
						
							|  |  |  | 	paro_ret__;							\ | 
					
						
							|  |  |  | }) | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:44 -06:00
										 |  |  | /*
 | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:47 -06:00
										 |  |  |  * xchg is implemented using cmpxchg without a lock prefix. xchg is | 
					
						
							|  |  |  |  * expensive due to the implied lock prefix.  The processor cannot prefetch | 
					
						
							|  |  |  |  * cachelines if xchg is used. | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:44 -06:00
										 |  |  |  */ | 
					
						
							|  |  |  | #define percpu_xchg_op(var, nval)					\
 | 
					
						
							|  |  |  | ({									\ | 
					
						
							|  |  |  | 	typeof(var) pxo_ret__;						\ | 
					
						
							|  |  |  | 	typeof(var) pxo_new__ = (nval);					\ | 
					
						
							|  |  |  | 	switch (sizeof(var)) {						\ | 
					
						
							|  |  |  | 	case 1:								\ | 
					
						
							| 
									
										
											  
											
												percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:
  2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics
Caused this 'perf top' crash:
 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...
Looking at assembly code, I found:
list = this_cpu_xchg(irq_work_list, NULL);
gives this wrong code : (gcc-4.1.2 cross compiler)
ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>
Tell gcc we dirty eax/rax register in percpu_xchg_op()
Compiler must use another register to store pxo_new__
We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax
Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax
After patch :
	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2011-01-25 17:31:54 +01:00
										 |  |  | 		asm("\n\tmov "__percpu_arg(1)",%%al"			\ | 
					
						
							|  |  |  | 		    "\n1:\tcmpxchgb %2, "__percpu_arg(1)		\ | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:47 -06:00
										 |  |  | 		    "\n\tjnz 1b"					\ | 
					
						
							| 
									
										
											  
											
												percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:
  2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics
Caused this 'perf top' crash:
 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...
Looking at assembly code, I found:
list = this_cpu_xchg(irq_work_list, NULL);
gives this wrong code : (gcc-4.1.2 cross compiler)
ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>
Tell gcc we dirty eax/rax register in percpu_xchg_op()
Compiler must use another register to store pxo_new__
We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax
Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax
After patch :
	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2011-01-25 17:31:54 +01:00
										 |  |  | 			    : "=&a" (pxo_ret__), "+m" (var)		\ | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:44 -06:00
										 |  |  | 			    : "q" (pxo_new__)				\ | 
					
						
							|  |  |  | 			    : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 2:								\ | 
					
						
							| 
									
										
											  
											
												percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:
  2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics
Caused this 'perf top' crash:
 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...
Looking at assembly code, I found:
list = this_cpu_xchg(irq_work_list, NULL);
gives this wrong code : (gcc-4.1.2 cross compiler)
ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>
Tell gcc we dirty eax/rax register in percpu_xchg_op()
Compiler must use another register to store pxo_new__
We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax
Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax
After patch :
	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2011-01-25 17:31:54 +01:00
										 |  |  | 		asm("\n\tmov "__percpu_arg(1)",%%ax"			\ | 
					
						
							|  |  |  | 		    "\n1:\tcmpxchgw %2, "__percpu_arg(1)		\ | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:47 -06:00
										 |  |  | 		    "\n\tjnz 1b"					\ | 
					
						
							| 
									
										
											  
											
												percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:
  2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics
Caused this 'perf top' crash:
 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...
Looking at assembly code, I found:
list = this_cpu_xchg(irq_work_list, NULL);
gives this wrong code : (gcc-4.1.2 cross compiler)
ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>
Tell gcc we dirty eax/rax register in percpu_xchg_op()
Compiler must use another register to store pxo_new__
We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax
Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax
After patch :
	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2011-01-25 17:31:54 +01:00
										 |  |  | 			    : "=&a" (pxo_ret__), "+m" (var)		\ | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:44 -06:00
										 |  |  | 			    : "r" (pxo_new__)				\ | 
					
						
							|  |  |  | 			    : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 4:								\ | 
					
						
							| 
									
										
											  
											
												percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:
  2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics
Caused this 'perf top' crash:
 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...
Looking at assembly code, I found:
list = this_cpu_xchg(irq_work_list, NULL);
gives this wrong code : (gcc-4.1.2 cross compiler)
ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>
Tell gcc we dirty eax/rax register in percpu_xchg_op()
Compiler must use another register to store pxo_new__
We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax
Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax
After patch :
	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2011-01-25 17:31:54 +01:00
										 |  |  | 		asm("\n\tmov "__percpu_arg(1)",%%eax"			\ | 
					
						
							|  |  |  | 		    "\n1:\tcmpxchgl %2, "__percpu_arg(1)		\ | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:47 -06:00
										 |  |  | 		    "\n\tjnz 1b"					\ | 
					
						
							| 
									
										
											  
											
												percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:
  2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics
Caused this 'perf top' crash:
 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...
Looking at assembly code, I found:
list = this_cpu_xchg(irq_work_list, NULL);
gives this wrong code : (gcc-4.1.2 cross compiler)
ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>
Tell gcc we dirty eax/rax register in percpu_xchg_op()
Compiler must use another register to store pxo_new__
We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax
Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax
After patch :
	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2011-01-25 17:31:54 +01:00
										 |  |  | 			    : "=&a" (pxo_ret__), "+m" (var)		\ | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:44 -06:00
										 |  |  | 			    : "r" (pxo_new__)				\ | 
					
						
							|  |  |  | 			    : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 8:								\ | 
					
						
							| 
									
										
											  
											
												percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:
  2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics
Caused this 'perf top' crash:
 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...
Looking at assembly code, I found:
list = this_cpu_xchg(irq_work_list, NULL);
gives this wrong code : (gcc-4.1.2 cross compiler)
ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>
Tell gcc we dirty eax/rax register in percpu_xchg_op()
Compiler must use another register to store pxo_new__
We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax
Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax
After patch :
	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2011-01-25 17:31:54 +01:00
										 |  |  | 		asm("\n\tmov "__percpu_arg(1)",%%rax"			\ | 
					
						
							|  |  |  | 		    "\n1:\tcmpxchgq %2, "__percpu_arg(1)		\ | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:47 -06:00
										 |  |  | 		    "\n\tjnz 1b"					\ | 
					
						
							| 
									
										
											  
											
												percpu, x86: Fix percpu_xchg_op()
These recent percpu commits:
  2485b6464cf8: x86,percpu: Move out of place 64 bit ops into X86_64 section
  8270137a0d50: cpuops: Use cmpxchg for xchg to avoid lock semantics
Caused this 'perf top' crash:
 Kernel panic - not syncing: Fatal exception in interrupt
 Pid: 0, comm: swapper Tainted: G     D
 2.6.38-rc2-00181-gef71723 #413 Call Trace: <IRQ> [<ffffffff810465b5>]
    ? panic
    ? kmsg_dump
    ? kmsg_dump
    ? oops_end
    ? no_context
    ? __bad_area_nosemaphore
    ? perf_output_begin
    ? bad_area_nosemaphore
    ? do_page_fault
    ? __task_pid_nr_ns
    ? perf_event_tid
    ? __perf_event_header__init_id
    ? validate_chain
    ? perf_output_sample
    ? trace_hardirqs_off
    ? page_fault
    ? irq_work_run
    ? update_process_times
    ? tick_sched_timer
    ? tick_sched_timer
    ? __run_hrtimer
    ? hrtimer_interrupt
    ? account_system_vtime
    ? smp_apic_timer_interrupt
    ? apic_timer_interrupt
 ...
Looking at assembly code, I found:
list = this_cpu_xchg(irq_work_list, NULL);
gives this wrong code : (gcc-4.1.2 cross compiler)
ffffffff810bc45e:
	mov    %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne    ffffffff810bc45e <irq_work_run+0x3e>
	test   %rax,%rax
	je     ffffffff810bc4aa <irq_work_run+0x8a>
Tell gcc we dirty eax/rax register in percpu_xchg_op()
Compiler must use another register to store pxo_new__
We also dont need to reload percpu value after a jump,
since a 'failed' cmpxchg already updated eax/rax
Wrong generated code was :
	xor     %rax,%rax   /* load 0 into %rax */
1:	mov     %gs:0xead0,%rax
	cmpxchg %rax,%gs:0xead0
	jne     1b
	test    %rax,%rax
After patch :
	xor     %rdx,%rdx   /* load 0 into %rdx */
	mov     %gs:0xead0,%rax
1:	cmpxchg %rdx,%gs:0xead0
	jne     1b:
	test    %rax,%rax
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>
LKML-Reference: <1295973114.3588.312.camel@edumazet-laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2011-01-25 17:31:54 +01:00
										 |  |  | 			    : "=&a" (pxo_ret__), "+m" (var)		\ | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:44 -06:00
										 |  |  | 			    : "r" (pxo_new__)				\ | 
					
						
							|  |  |  | 			    : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	default: __bad_percpu_size();					\ | 
					
						
							|  |  |  | 	}								\ | 
					
						
							|  |  |  | 	pxo_ret__;							\ | 
					
						
							|  |  |  | }) | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | /*
 | 
					
						
							|  |  |  |  * cmpxchg has no such implied lock semantics as a result it is much | 
					
						
							|  |  |  |  * more efficient for cpu local operations. | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | #define percpu_cmpxchg_op(var, oval, nval)				\
 | 
					
						
							|  |  |  | ({									\ | 
					
						
							|  |  |  | 	typeof(var) pco_ret__;						\ | 
					
						
							|  |  |  | 	typeof(var) pco_old__ = (oval);					\ | 
					
						
							|  |  |  | 	typeof(var) pco_new__ = (nval);					\ | 
					
						
							|  |  |  | 	switch (sizeof(var)) {						\ | 
					
						
							|  |  |  | 	case 1:								\ | 
					
						
							|  |  |  | 		asm("cmpxchgb %2, "__percpu_arg(1)			\ | 
					
						
							|  |  |  | 			    : "=a" (pco_ret__), "+m" (var)		\ | 
					
						
							|  |  |  | 			    : "q" (pco_new__), "0" (pco_old__)		\ | 
					
						
							|  |  |  | 			    : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 2:								\ | 
					
						
							|  |  |  | 		asm("cmpxchgw %2, "__percpu_arg(1)			\ | 
					
						
							|  |  |  | 			    : "=a" (pco_ret__), "+m" (var)		\ | 
					
						
							|  |  |  | 			    : "r" (pco_new__), "0" (pco_old__)		\ | 
					
						
							|  |  |  | 			    : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 4:								\ | 
					
						
							|  |  |  | 		asm("cmpxchgl %2, "__percpu_arg(1)			\ | 
					
						
							|  |  |  | 			    : "=a" (pco_ret__), "+m" (var)		\ | 
					
						
							|  |  |  | 			    : "r" (pco_new__), "0" (pco_old__)		\ | 
					
						
							|  |  |  | 			    : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	case 8:								\ | 
					
						
							|  |  |  | 		asm("cmpxchgq %2, "__percpu_arg(1)			\ | 
					
						
							|  |  |  | 			    : "=a" (pco_ret__), "+m" (var)		\ | 
					
						
							|  |  |  | 			    : "r" (pco_new__), "0" (pco_old__)		\ | 
					
						
							|  |  |  | 			    : "memory");				\ | 
					
						
							|  |  |  | 		break;							\ | 
					
						
							|  |  |  | 	default: __bad_percpu_size();					\ | 
					
						
							|  |  |  | 	}								\ | 
					
						
							|  |  |  | 	pco_ret__;							\ | 
					
						
							|  |  |  | }) | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2009-08-03 14:08:48 +09:00
										 |  |  | /*
 | 
					
						
							| 
									
										
										
										
											2012-05-14 14:15:32 -07:00
										 |  |  |  * this_cpu_read() makes gcc load the percpu variable every time it is | 
					
						
							| 
									
										
										
										
											2012-05-11 15:35:27 +08:00
										 |  |  |  * accessed while this_cpu_read_stable() allows the value to be cached. | 
					
						
							|  |  |  |  * this_cpu_read_stable() is more efficient and can be used if its value | 
					
						
							| 
									
										
										
										
											2009-08-03 14:08:48 +09:00
										 |  |  |  * is guaranteed to be valid across cpus.  The current users include | 
					
						
							|  |  |  |  * get_current() and get_thread_info() both of which are actually | 
					
						
							|  |  |  |  * per-thread variables implemented as per-cpu variables and thus | 
					
						
							|  |  |  |  * stable for the duration of the respective task. | 
					
						
							|  |  |  |  */ | 
					
						
							| 
									
										
										
										
											2014-11-04 08:50:48 +00:00
										 |  |  | #define this_cpu_read_stable(var)	percpu_stable_op("mov", var)
 | 
					
						
							| 
									
										
										
										
											2009-01-13 20:41:35 +09:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2014-11-04 08:50:48 +00:00
										 |  |  | #define raw_cpu_read_1(pcp)		percpu_from_op("mov", pcp)
 | 
					
						
							|  |  |  | #define raw_cpu_read_2(pcp)		percpu_from_op("mov", pcp)
 | 
					
						
							|  |  |  | #define raw_cpu_read_4(pcp)		percpu_from_op("mov", pcp)
 | 
					
						
							| 
									
										
										
										
											2014-04-07 15:39:34 -07:00
										 |  |  | 
 | 
					
						
							|  |  |  | #define raw_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_add_1(pcp, val)		percpu_add_op((pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_add_2(pcp, val)		percpu_add_op((pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_add_4(pcp, val)		percpu_add_op((pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_and_1(pcp, val)		percpu_to_op("and", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_and_2(pcp, val)		percpu_to_op("and", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_and_4(pcp, val)		percpu_to_op("and", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_or_1(pcp, val)		percpu_to_op("or", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_or_2(pcp, val)		percpu_to_op("or", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_or_4(pcp, val)		percpu_to_op("or", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_xchg_1(pcp, val)	percpu_xchg_op(pcp, val)
 | 
					
						
							|  |  |  | #define raw_cpu_xchg_2(pcp, val)	percpu_xchg_op(pcp, val)
 | 
					
						
							|  |  |  | #define raw_cpu_xchg_4(pcp, val)	percpu_xchg_op(pcp, val)
 | 
					
						
							| 
									
										
										
										
											2009-10-03 19:48:22 +09:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2014-11-04 08:50:48 +00:00
										 |  |  | #define this_cpu_read_1(pcp)		percpu_from_op("mov", pcp)
 | 
					
						
							|  |  |  | #define this_cpu_read_2(pcp)		percpu_from_op("mov", pcp)
 | 
					
						
							|  |  |  | #define this_cpu_read_4(pcp)		percpu_from_op("mov", pcp)
 | 
					
						
							| 
									
										
										
										
											2009-10-03 19:48:22 +09:00
										 |  |  | #define this_cpu_write_1(pcp, val)	percpu_to_op("mov", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_write_2(pcp, val)	percpu_to_op("mov", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_write_4(pcp, val)	percpu_to_op("mov", (pcp), val)
 | 
					
						
							| 
									
										
										
										
											2010-01-05 15:34:50 +09:00
										 |  |  | #define this_cpu_add_1(pcp, val)	percpu_add_op((pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_add_2(pcp, val)	percpu_add_op((pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_add_4(pcp, val)	percpu_add_op((pcp), val)
 | 
					
						
							| 
									
										
										
										
											2009-10-03 19:48:22 +09:00
										 |  |  | #define this_cpu_and_1(pcp, val)	percpu_to_op("and", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_and_2(pcp, val)	percpu_to_op("and", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_and_4(pcp, val)	percpu_to_op("and", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_or_1(pcp, val)		percpu_to_op("or", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_or_2(pcp, val)		percpu_to_op("or", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_or_4(pcp, val)		percpu_to_op("or", (pcp), val)
 | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:44 -06:00
										 |  |  | #define this_cpu_xchg_1(pcp, nval)	percpu_xchg_op(pcp, nval)
 | 
					
						
							|  |  |  | #define this_cpu_xchg_2(pcp, nval)	percpu_xchg_op(pcp, nval)
 | 
					
						
							|  |  |  | #define this_cpu_xchg_4(pcp, nval)	percpu_xchg_op(pcp, nval)
 | 
					
						
							| 
									
										
										
										
											2009-10-03 19:48:22 +09:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2014-04-07 15:39:34 -07:00
										 |  |  | #define raw_cpu_add_return_1(pcp, val)		percpu_add_return_op(pcp, val)
 | 
					
						
							|  |  |  | #define raw_cpu_add_return_2(pcp, val)		percpu_add_return_op(pcp, val)
 | 
					
						
							|  |  |  | #define raw_cpu_add_return_4(pcp, val)		percpu_add_return_op(pcp, val)
 | 
					
						
							|  |  |  | #define raw_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
 | 
					
						
							|  |  |  | #define raw_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
 | 
					
						
							|  |  |  | #define raw_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
 | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:44 -06:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2014-04-07 15:39:34 -07:00
										 |  |  | #define this_cpu_add_return_1(pcp, val)		percpu_add_return_op(pcp, val)
 | 
					
						
							|  |  |  | #define this_cpu_add_return_2(pcp, val)		percpu_add_return_op(pcp, val)
 | 
					
						
							|  |  |  | #define this_cpu_add_return_4(pcp, val)		percpu_add_return_op(pcp, val)
 | 
					
						
							| 
									
										
										
										
											2010-12-14 10:28:44 -06:00
										 |  |  | #define this_cpu_cmpxchg_1(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
 | 
					
						
							|  |  |  | #define this_cpu_cmpxchg_2(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
 | 
					
						
							|  |  |  | #define this_cpu_cmpxchg_4(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
 | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | #ifdef CONFIG_X86_CMPXCHG64
 | 
					
						
							| 
									
										
										
										
											2011-12-14 08:33:25 +00:00
										 |  |  | #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2)		\
 | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | ({									\ | 
					
						
							| 
									
										
										
										
											2011-12-14 08:33:25 +00:00
										 |  |  | 	bool __ret;							\ | 
					
						
							|  |  |  | 	typeof(pcp1) __o1 = (o1), __n1 = (n1);				\ | 
					
						
							|  |  |  | 	typeof(pcp2) __o2 = (o2), __n2 = (n2);				\ | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | 	asm volatile("cmpxchg8b "__percpu_arg(1)"\n\tsetz %0\n\t"	\ | 
					
						
							| 
									
										
										
										
											2011-12-14 08:33:25 +00:00
										 |  |  | 		    : "=a" (__ret), "+m" (pcp1), "+m" (pcp2), "+d" (__o2) \ | 
					
						
							|  |  |  | 		    :  "b" (__n1), "c" (__n2), "a" (__o1));		\ | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | 	__ret;								\ | 
					
						
							|  |  |  | }) | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2014-04-07 15:39:34 -07:00
										 |  |  | #define raw_cpu_cmpxchg_double_4	percpu_cmpxchg8b_double
 | 
					
						
							| 
									
										
										
										
											2011-12-14 08:33:25 +00:00
										 |  |  | #define this_cpu_cmpxchg_double_4	percpu_cmpxchg8b_double
 | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | #endif /* CONFIG_X86_CMPXCHG64 */
 | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2009-10-03 19:48:22 +09:00
										 |  |  | /*
 | 
					
						
							|  |  |  |  * Per cpu atomic 64 bit operations are only available under 64 bit. | 
					
						
							|  |  |  |  * 32 bit must fall back to generic operations. | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | #ifdef CONFIG_X86_64
 | 
					
						
							| 
									
										
										
										
											2014-11-04 08:50:48 +00:00
										 |  |  | #define raw_cpu_read_8(pcp)			percpu_from_op("mov", pcp)
 | 
					
						
							| 
									
										
										
										
											2014-04-07 15:39:34 -07:00
										 |  |  | #define raw_cpu_write_8(pcp, val)		percpu_to_op("mov", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_add_8(pcp, val)			percpu_add_op((pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_and_8(pcp, val)			percpu_to_op("and", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_or_8(pcp, val)			percpu_to_op("or", (pcp), val)
 | 
					
						
							|  |  |  | #define raw_cpu_add_return_8(pcp, val)		percpu_add_return_op(pcp, val)
 | 
					
						
							|  |  |  | #define raw_cpu_xchg_8(pcp, nval)		percpu_xchg_op(pcp, nval)
 | 
					
						
							|  |  |  | #define raw_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
 | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2014-11-04 08:50:48 +00:00
										 |  |  | #define this_cpu_read_8(pcp)			percpu_from_op("mov", pcp)
 | 
					
						
							| 
									
										
										
										
											2014-04-07 15:39:34 -07:00
										 |  |  | #define this_cpu_write_8(pcp, val)		percpu_to_op("mov", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_add_8(pcp, val)		percpu_add_op((pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_and_8(pcp, val)		percpu_to_op("and", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_or_8(pcp, val)			percpu_to_op("or", (pcp), val)
 | 
					
						
							|  |  |  | #define this_cpu_add_return_8(pcp, val)		percpu_add_return_op(pcp, val)
 | 
					
						
							|  |  |  | #define this_cpu_xchg_8(pcp, nval)		percpu_xchg_op(pcp, nval)
 | 
					
						
							| 
									
										
										
										
											2011-01-11 18:54:53 +01:00
										 |  |  | #define this_cpu_cmpxchg_8(pcp, oval, nval)	percpu_cmpxchg_op(pcp, oval, nval)
 | 
					
						
							| 
									
										
										
										
											2009-10-03 19:48:22 +09:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | /*
 | 
					
						
							|  |  |  |  * Pretty complex macro to generate cmpxchg16 instruction.  The instruction | 
					
						
							|  |  |  |  * is not supported on early AMD64 processors so we must be able to emulate | 
					
						
							|  |  |  |  * it in software.  The address used in the cmpxchg16 instruction must be | 
					
						
							|  |  |  |  * aligned to a 16 byte boundary. | 
					
						
							|  |  |  |  */ | 
					
						
							| 
									
										
										
										
											2011-12-14 08:33:25 +00:00
										 |  |  | #define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2)		\
 | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | ({									\ | 
					
						
							| 
									
										
										
										
											2011-12-14 08:33:25 +00:00
										 |  |  | 	bool __ret;							\ | 
					
						
							|  |  |  | 	typeof(pcp1) __o1 = (o1), __n1 = (n1);				\ | 
					
						
							|  |  |  | 	typeof(pcp2) __o2 = (o2), __n2 = (n2);				\ | 
					
						
							|  |  |  | 	alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \ | 
					
						
							|  |  |  | 		       "cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t",	\ | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | 		       X86_FEATURE_CX16,				\ | 
					
						
							| 
									
										
										
										
											2011-12-14 08:33:25 +00:00
										 |  |  | 		       ASM_OUTPUT2("=a" (__ret), "+m" (pcp1),		\ | 
					
						
							|  |  |  | 				   "+m" (pcp2), "+d" (__o2)),		\ | 
					
						
							|  |  |  | 		       "b" (__n1), "c" (__n2), "a" (__o1) : "rsi");	\ | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | 	__ret;								\ | 
					
						
							|  |  |  | }) | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2014-04-07 15:39:34 -07:00
										 |  |  | #define raw_cpu_cmpxchg_double_8	percpu_cmpxchg16b_double
 | 
					
						
							| 
									
										
										
										
											2011-12-14 08:33:25 +00:00
										 |  |  | #define this_cpu_cmpxchg_double_8	percpu_cmpxchg16b_double
 | 
					
						
							| 
									
										
										
										
											2011-02-28 11:02:24 +01:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2009-10-03 19:48:22 +09:00
										 |  |  | #endif
 | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2009-01-13 20:41:35 +09:00
										 |  |  | /* This is not atomic against other CPUs -- CPU preemption needs to be off */ | 
					
						
							|  |  |  | #define x86_test_and_clear_bit_percpu(bit, var)				\
 | 
					
						
							|  |  |  | ({									\ | 
					
						
							|  |  |  | 	int old__;							\ | 
					
						
							| 
									
										
										
										
											2009-01-19 00:38:59 +09:00
										 |  |  | 	asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0"		\ | 
					
						
							| 
									
										
										
										
											2009-10-29 22:34:15 +09:00
										 |  |  | 		     : "=r" (old__), "+m" (var)				\ | 
					
						
							| 
									
										
										
										
											2009-01-19 00:38:59 +09:00
										 |  |  | 		     : "dIr" (bit));					\ | 
					
						
							| 
									
										
										
										
											2009-01-13 20:41:35 +09:00
										 |  |  | 	old__;								\ | 
					
						
							|  |  |  | }) | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2011-03-12 12:50:10 +01:00
										 |  |  | static __always_inline int x86_this_cpu_constant_test_bit(unsigned int nr, | 
					
						
							|  |  |  |                         const unsigned long __percpu *addr) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	unsigned long __percpu *a = (unsigned long *)addr + nr / BITS_PER_LONG; | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2012-05-14 14:15:32 -07:00
										 |  |  | #ifdef CONFIG_X86_64
 | 
					
						
							| 
									
										
										
										
											2014-04-07 15:39:34 -07:00
										 |  |  | 	return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_8(*a)) != 0; | 
					
						
							| 
									
										
										
										
											2012-05-14 14:15:32 -07:00
										 |  |  | #else
 | 
					
						
							| 
									
										
										
										
											2014-04-07 15:39:34 -07:00
										 |  |  | 	return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_4(*a)) != 0; | 
					
						
							| 
									
										
										
										
											2012-05-14 14:15:32 -07:00
										 |  |  | #endif
 | 
					
						
							| 
									
										
										
										
											2011-03-12 12:50:10 +01:00
										 |  |  | } | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | static inline int x86_this_cpu_variable_test_bit(int nr, | 
					
						
							|  |  |  |                         const unsigned long __percpu *addr) | 
					
						
							|  |  |  | { | 
					
						
							|  |  |  | 	int oldbit; | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | 	asm volatile("bt "__percpu_arg(2)",%1\n\t" | 
					
						
							|  |  |  | 			"sbb %0,%0" | 
					
						
							|  |  |  | 			: "=r" (oldbit) | 
					
						
							|  |  |  | 			: "m" (*(unsigned long *)addr), "Ir" (nr)); | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | 	return oldbit; | 
					
						
							|  |  |  | } | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | #define x86_this_cpu_test_bit(nr, addr)			\
 | 
					
						
							|  |  |  | 	(__builtin_constant_p((nr))			\ | 
					
						
							|  |  |  | 	 ? x86_this_cpu_constant_test_bit((nr), (addr))	\ | 
					
						
							|  |  |  | 	 : x86_this_cpu_variable_test_bit((nr), (addr))) | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
											  
											
												percpu: add optimized generic percpu accessors
It is an optimization and a cleanup, and adds the following new
generic percpu methods:
  percpu_read()
  percpu_write()
  percpu_add()
  percpu_sub()
  percpu_and()
  percpu_or()
  percpu_xor()
and implements support for them on x86. (other architectures will fall
back to a default implementation)
The advantage is that for example to read a local percpu variable,
instead of this sequence:
 return __get_cpu_var(var);
 ffffffff8102ca2b:	48 8b 14 fd 80 09 74 	mov    -0x7e8bf680(,%rdi,8),%rdx
 ffffffff8102ca32:	81
 ffffffff8102ca33:	48 c7 c0 d8 59 00 00 	mov    $0x59d8,%rax
 ffffffff8102ca3a:	48 8b 04 10          	mov    (%rax,%rdx,1),%rax
We can get a single instruction by using the optimized variants:
 return percpu_read(var);
 ffffffff8102ca3f:	65 48 8b 05 91 8f fd 	mov    %gs:0x7efd8f91(%rip),%rax
I also cleaned up the x86-specific APIs and made the x86 code use
these new generic percpu primitives.
tj: * fixed generic percpu_sub() definition as Roel Kluin pointed out
    * added percpu_and() for completeness's sake
    * made generic percpu ops atomic against preemption
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Tejun Heo <tj@kernel.org>
											
										 
											2009-01-15 22:15:53 +09:00
										 |  |  | #include <asm-generic/percpu.h>
 | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | /* We can use this directly for local CPU (faster). */ | 
					
						
							| 
									
										
										
										
											2014-11-04 08:26:42 +00:00
										 |  |  | DECLARE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off); | 
					
						
							| 
									
										
											  
											
												percpu: add optimized generic percpu accessors
It is an optimization and a cleanup, and adds the following new
generic percpu methods:
  percpu_read()
  percpu_write()
  percpu_add()
  percpu_sub()
  percpu_and()
  percpu_or()
  percpu_xor()
and implements support for them on x86. (other architectures will fall
back to a default implementation)
The advantage is that for example to read a local percpu variable,
instead of this sequence:
 return __get_cpu_var(var);
 ffffffff8102ca2b:	48 8b 14 fd 80 09 74 	mov    -0x7e8bf680(,%rdi,8),%rdx
 ffffffff8102ca32:	81
 ffffffff8102ca33:	48 c7 c0 d8 59 00 00 	mov    $0x59d8,%rax
 ffffffff8102ca3a:	48 8b 04 10          	mov    (%rax,%rdx,1),%rax
We can get a single instruction by using the optimized variants:
 return percpu_read(var);
 ffffffff8102ca3f:	65 48 8b 05 91 8f fd 	mov    %gs:0x7efd8f91(%rip),%rax
I also cleaned up the x86-specific APIs and made the x86 code use
these new generic percpu primitives.
tj: * fixed generic percpu_sub() definition as Roel Kluin pointed out
    * added percpu_and() for completeness's sake
    * made generic percpu ops atomic against preemption
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Tejun Heo <tj@kernel.org>
											
										 
											2009-01-15 22:15:53 +09:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2008-01-30 13:32:53 +01:00
										 |  |  | #endif /* !__ASSEMBLY__ */
 | 
					
						
							| 
									
										
											  
											
												x86: cleanup early per cpu variables/accesses v4
  * Introduce a new PER_CPU macro called "EARLY_PER_CPU".  This is
    used by some per_cpu variables that are initialized and accessed
    before there are per_cpu areas allocated.
    ["Early" in respect to per_cpu variables is "earlier than the per_cpu
    areas have been setup".]
    This patchset adds these new macros:
	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)
	EXPORT_EARLY_PER_CPU_SYMBOL(_name)
	DECLARE_EARLY_PER_CPU(_type, _name)
	early_per_cpu_ptr(_name)
	early_per_cpu_map(_name, _idx)
	early_per_cpu(_name, _cpu)
    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.
    The early_per_cpu() macro is not very efficient but does show how to
    access the variable if you have a function that can be called both
    "early" and "late".  It tests the early ptr to be NULL, and if not
    then it's still valid.  Otherwise, the per_cpu variable is used
    instead:
	#define early_per_cpu(_name, _cpu) 			\
		(early_per_cpu_ptr(_name) ?			\
			early_per_cpu_ptr(_name)[_cpu] :	\
			per_cpu(_name, _cpu))
    A better method is to actually check the pointer manually.  In the
    case below, numa_set_node can be called both "early" and "late":
	void __cpuinit numa_set_node(int cpu, int node)
	{
	    int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
	    if (cpu_to_node_map)
		    cpu_to_node_map[cpu] = node;
	    else
		    per_cpu(x86_cpu_to_node_map, cpu) = node;
	}
  * Add a flag "arch_provides_topology_pointers" that indicates pointers
    to topology cpumask_t maps are available.  Otherwise, use the function
    returning the cpumask_t value.  This is useful if cpumask_t set size
    is very large to avoid copying data on to/off of the stack.
  * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while
    the non-debug case has been optimized a bit.
  * Remove an unreferenced compiler warning in drivers/base/topology.c
  * Clean up #ifdef in setup.c
For inclusion into sched-devel/latest tree.
Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
											
										 
											2008-05-12 21:21:12 +02:00
										 |  |  | 
 | 
					
						
							|  |  |  | #ifdef CONFIG_SMP
 | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | /*
 | 
					
						
							|  |  |  |  * Define the "EARLY_PER_CPU" macros.  These are used for some per_cpu | 
					
						
							|  |  |  |  * variables that are initialized and accessed before there are per_cpu | 
					
						
							|  |  |  |  * areas allocated. | 
					
						
							|  |  |  |  */ | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | #define	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)			\
 | 
					
						
							|  |  |  | 	DEFINE_PER_CPU(_type, _name) = _initvalue;			\ | 
					
						
							|  |  |  | 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\ | 
					
						
							|  |  |  | 				{ [0 ... NR_CPUS-1] = _initvalue };	\ | 
					
						
							| 
									
										
											  
											
												x86, percpu: silence section mismatch warnings related to EARLY_PER_CPU variables
Quoting Mike Travis in "x86: cleanup early per cpu variables/accesses v4"
(23ca4bba3e20c6c3cb11c1bb0ab4770b724d39ac):
    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.
As these variables are NULL'ed before __init sections are dropped
(in setup_per_cpu_maps), they can be safely annotated as __ref.
This change silences following section mismatch warnings:
WARNING: vmlinux.o(.data+0x46c0): Section mismatch in reference from the variable x86_cpu_to_apicid_early_ptr to the variable .init.data:x86_cpu_to_apicid_early_map
The variable x86_cpu_to_apicid_early_ptr references
the variable __initdata x86_cpu_to_apicid_early_map
If the reference is valid then annotate the
variable with __init* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,
WARNING: vmlinux.o(.data+0x46c8): Section mismatch in reference from the variable x86_bios_cpu_apicid_early_ptr to the variable .init.data:x86_bios_cpu_apicid_early_map
The variable x86_bios_cpu_apicid_early_ptr references
the variable __initdata x86_bios_cpu_apicid_early_map
If the reference is valid then annotate the
variable with __init* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,
WARNING: vmlinux.o(.data+0x46d0): Section mismatch in reference from the variable x86_cpu_to_node_map_early_ptr to the variable .init.data:x86_cpu_to_node_map_early_map
The variable x86_cpu_to_node_map_early_ptr references
the variable __initdata x86_cpu_to_node_map_early_map
If the reference is valid then annotate the
variable with __init* (see linux/init.h) or name the variable:
*driver, *_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console,
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
											
										 
											2008-08-17 17:50:50 +02:00
										 |  |  | 	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map | 
					
						
							| 
									
										
											  
											
												x86: cleanup early per cpu variables/accesses v4
  * Introduce a new PER_CPU macro called "EARLY_PER_CPU".  This is
    used by some per_cpu variables that are initialized and accessed
    before there are per_cpu areas allocated.
    ["Early" in respect to per_cpu variables is "earlier than the per_cpu
    areas have been setup".]
    This patchset adds these new macros:
	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)
	EXPORT_EARLY_PER_CPU_SYMBOL(_name)
	DECLARE_EARLY_PER_CPU(_type, _name)
	early_per_cpu_ptr(_name)
	early_per_cpu_map(_name, _idx)
	early_per_cpu(_name, _cpu)
    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.
    The early_per_cpu() macro is not very efficient but does show how to
    access the variable if you have a function that can be called both
    "early" and "late".  It tests the early ptr to be NULL, and if not
    then it's still valid.  Otherwise, the per_cpu variable is used
    instead:
	#define early_per_cpu(_name, _cpu) 			\
		(early_per_cpu_ptr(_name) ?			\
			early_per_cpu_ptr(_name)[_cpu] :	\
			per_cpu(_name, _cpu))
    A better method is to actually check the pointer manually.  In the
    case below, numa_set_node can be called both "early" and "late":
	void __cpuinit numa_set_node(int cpu, int node)
	{
	    int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
	    if (cpu_to_node_map)
		    cpu_to_node_map[cpu] = node;
	    else
		    per_cpu(x86_cpu_to_node_map, cpu) = node;
	}
  * Add a flag "arch_provides_topology_pointers" that indicates pointers
    to topology cpumask_t maps are available.  Otherwise, use the function
    returning the cpumask_t value.  This is useful if cpumask_t set size
    is very large to avoid copying data on to/off of the stack.
  * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while
    the non-debug case has been optimized a bit.
  * Remove an unreferenced compiler warning in drivers/base/topology.c
  * Clean up #ifdef in setup.c
For inclusion into sched-devel/latest tree.
Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
											
										 
											2008-05-12 21:21:12 +02:00
										 |  |  | 
 | 
					
						
							| 
									
										
										
										
											2012-06-11 12:56:45 +03:00
										 |  |  | #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)	\
 | 
					
						
							|  |  |  | 	DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue;		\ | 
					
						
							|  |  |  | 	__typeof__(_type) _name##_early_map[NR_CPUS] __initdata =	\ | 
					
						
							|  |  |  | 				{ [0 ... NR_CPUS-1] = _initvalue };	\ | 
					
						
							|  |  |  | 	__typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
											  
											
												x86: cleanup early per cpu variables/accesses v4
  * Introduce a new PER_CPU macro called "EARLY_PER_CPU".  This is
    used by some per_cpu variables that are initialized and accessed
    before there are per_cpu areas allocated.
    ["Early" in respect to per_cpu variables is "earlier than the per_cpu
    areas have been setup".]
    This patchset adds these new macros:
	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)
	EXPORT_EARLY_PER_CPU_SYMBOL(_name)
	DECLARE_EARLY_PER_CPU(_type, _name)
	early_per_cpu_ptr(_name)
	early_per_cpu_map(_name, _idx)
	early_per_cpu(_name, _cpu)
    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.
    The early_per_cpu() macro is not very efficient but does show how to
    access the variable if you have a function that can be called both
    "early" and "late".  It tests the early ptr to be NULL, and if not
    then it's still valid.  Otherwise, the per_cpu variable is used
    instead:
	#define early_per_cpu(_name, _cpu) 			\
		(early_per_cpu_ptr(_name) ?			\
			early_per_cpu_ptr(_name)[_cpu] :	\
			per_cpu(_name, _cpu))
    A better method is to actually check the pointer manually.  In the
    case below, numa_set_node can be called both "early" and "late":
	void __cpuinit numa_set_node(int cpu, int node)
	{
	    int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
	    if (cpu_to_node_map)
		    cpu_to_node_map[cpu] = node;
	    else
		    per_cpu(x86_cpu_to_node_map, cpu) = node;
	}
  * Add a flag "arch_provides_topology_pointers" that indicates pointers
    to topology cpumask_t maps are available.  Otherwise, use the function
    returning the cpumask_t value.  This is useful if cpumask_t set size
    is very large to avoid copying data on to/off of the stack.
  * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while
    the non-debug case has been optimized a bit.
  * Remove an unreferenced compiler warning in drivers/base/topology.c
  * Clean up #ifdef in setup.c
For inclusion into sched-devel/latest tree.
Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
											
										 
											2008-05-12 21:21:12 +02:00
										 |  |  | #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
 | 
					
						
							|  |  |  | 	EXPORT_PER_CPU_SYMBOL(_name) | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | #define DECLARE_EARLY_PER_CPU(_type, _name)			\
 | 
					
						
							|  |  |  | 	DECLARE_PER_CPU(_type, _name);				\ | 
					
						
							|  |  |  | 	extern __typeof__(_type) *_name##_early_ptr;		\ | 
					
						
							|  |  |  | 	extern __typeof__(_type)  _name##_early_map[] | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2012-06-11 12:56:45 +03:00
										 |  |  | #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)		\
 | 
					
						
							|  |  |  | 	DECLARE_PER_CPU_READ_MOSTLY(_type, _name);		\ | 
					
						
							|  |  |  | 	extern __typeof__(_type) *_name##_early_ptr;		\ | 
					
						
							|  |  |  | 	extern __typeof__(_type)  _name##_early_map[] | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
											  
											
												x86: cleanup early per cpu variables/accesses v4
  * Introduce a new PER_CPU macro called "EARLY_PER_CPU".  This is
    used by some per_cpu variables that are initialized and accessed
    before there are per_cpu areas allocated.
    ["Early" in respect to per_cpu variables is "earlier than the per_cpu
    areas have been setup".]
    This patchset adds these new macros:
	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)
	EXPORT_EARLY_PER_CPU_SYMBOL(_name)
	DECLARE_EARLY_PER_CPU(_type, _name)
	early_per_cpu_ptr(_name)
	early_per_cpu_map(_name, _idx)
	early_per_cpu(_name, _cpu)
    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.
    The early_per_cpu() macro is not very efficient but does show how to
    access the variable if you have a function that can be called both
    "early" and "late".  It tests the early ptr to be NULL, and if not
    then it's still valid.  Otherwise, the per_cpu variable is used
    instead:
	#define early_per_cpu(_name, _cpu) 			\
		(early_per_cpu_ptr(_name) ?			\
			early_per_cpu_ptr(_name)[_cpu] :	\
			per_cpu(_name, _cpu))
    A better method is to actually check the pointer manually.  In the
    case below, numa_set_node can be called both "early" and "late":
	void __cpuinit numa_set_node(int cpu, int node)
	{
	    int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
	    if (cpu_to_node_map)
		    cpu_to_node_map[cpu] = node;
	    else
		    per_cpu(x86_cpu_to_node_map, cpu) = node;
	}
  * Add a flag "arch_provides_topology_pointers" that indicates pointers
    to topology cpumask_t maps are available.  Otherwise, use the function
    returning the cpumask_t value.  This is useful if cpumask_t set size
    is very large to avoid copying data on to/off of the stack.
  * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while
    the non-debug case has been optimized a bit.
  * Remove an unreferenced compiler warning in drivers/base/topology.c
  * Clean up #ifdef in setup.c
For inclusion into sched-devel/latest tree.
Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
											
										 
											2008-05-12 21:21:12 +02:00
										 |  |  | #define	early_per_cpu_ptr(_name) (_name##_early_ptr)
 | 
					
						
							|  |  |  | #define	early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
 | 
					
						
							|  |  |  | #define	early_per_cpu(_name, _cpu) 				\
 | 
					
						
							| 
									
										
										
										
											2009-01-13 20:41:34 +09:00
										 |  |  | 	*(early_per_cpu_ptr(_name) ?				\ | 
					
						
							|  |  |  | 		&early_per_cpu_ptr(_name)[_cpu] :		\ | 
					
						
							|  |  |  | 		&per_cpu(_name, _cpu)) | 
					
						
							| 
									
										
											  
											
												x86: cleanup early per cpu variables/accesses v4
  * Introduce a new PER_CPU macro called "EARLY_PER_CPU".  This is
    used by some per_cpu variables that are initialized and accessed
    before there are per_cpu areas allocated.
    ["Early" in respect to per_cpu variables is "earlier than the per_cpu
    areas have been setup".]
    This patchset adds these new macros:
	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)
	EXPORT_EARLY_PER_CPU_SYMBOL(_name)
	DECLARE_EARLY_PER_CPU(_type, _name)
	early_per_cpu_ptr(_name)
	early_per_cpu_map(_name, _idx)
	early_per_cpu(_name, _cpu)
    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.
    The early_per_cpu() macro is not very efficient but does show how to
    access the variable if you have a function that can be called both
    "early" and "late".  It tests the early ptr to be NULL, and if not
    then it's still valid.  Otherwise, the per_cpu variable is used
    instead:
	#define early_per_cpu(_name, _cpu) 			\
		(early_per_cpu_ptr(_name) ?			\
			early_per_cpu_ptr(_name)[_cpu] :	\
			per_cpu(_name, _cpu))
    A better method is to actually check the pointer manually.  In the
    case below, numa_set_node can be called both "early" and "late":
	void __cpuinit numa_set_node(int cpu, int node)
	{
	    int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
	    if (cpu_to_node_map)
		    cpu_to_node_map[cpu] = node;
	    else
		    per_cpu(x86_cpu_to_node_map, cpu) = node;
	}
  * Add a flag "arch_provides_topology_pointers" that indicates pointers
    to topology cpumask_t maps are available.  Otherwise, use the function
    returning the cpumask_t value.  This is useful if cpumask_t set size
    is very large to avoid copying data on to/off of the stack.
  * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while
    the non-debug case has been optimized a bit.
  * Remove an unreferenced compiler warning in drivers/base/topology.c
  * Clean up #ifdef in setup.c
For inclusion into sched-devel/latest tree.
Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
											
										 
											2008-05-12 21:21:12 +02:00
										 |  |  | 
 | 
					
						
							|  |  |  | #else	/* !CONFIG_SMP */
 | 
					
						
							|  |  |  | #define	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)		\
 | 
					
						
							|  |  |  | 	DEFINE_PER_CPU(_type, _name) = _initvalue | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2012-06-11 12:56:45 +03:00
										 |  |  | #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue)	\
 | 
					
						
							|  |  |  | 	DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
											  
											
												x86: cleanup early per cpu variables/accesses v4
  * Introduce a new PER_CPU macro called "EARLY_PER_CPU".  This is
    used by some per_cpu variables that are initialized and accessed
    before there are per_cpu areas allocated.
    ["Early" in respect to per_cpu variables is "earlier than the per_cpu
    areas have been setup".]
    This patchset adds these new macros:
	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)
	EXPORT_EARLY_PER_CPU_SYMBOL(_name)
	DECLARE_EARLY_PER_CPU(_type, _name)
	early_per_cpu_ptr(_name)
	early_per_cpu_map(_name, _idx)
	early_per_cpu(_name, _cpu)
    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.
    The early_per_cpu() macro is not very efficient but does show how to
    access the variable if you have a function that can be called both
    "early" and "late".  It tests the early ptr to be NULL, and if not
    then it's still valid.  Otherwise, the per_cpu variable is used
    instead:
	#define early_per_cpu(_name, _cpu) 			\
		(early_per_cpu_ptr(_name) ?			\
			early_per_cpu_ptr(_name)[_cpu] :	\
			per_cpu(_name, _cpu))
    A better method is to actually check the pointer manually.  In the
    case below, numa_set_node can be called both "early" and "late":
	void __cpuinit numa_set_node(int cpu, int node)
	{
	    int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
	    if (cpu_to_node_map)
		    cpu_to_node_map[cpu] = node;
	    else
		    per_cpu(x86_cpu_to_node_map, cpu) = node;
	}
  * Add a flag "arch_provides_topology_pointers" that indicates pointers
    to topology cpumask_t maps are available.  Otherwise, use the function
    returning the cpumask_t value.  This is useful if cpumask_t set size
    is very large to avoid copying data on to/off of the stack.
  * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while
    the non-debug case has been optimized a bit.
  * Remove an unreferenced compiler warning in drivers/base/topology.c
  * Clean up #ifdef in setup.c
For inclusion into sched-devel/latest tree.
Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
											
										 
											2008-05-12 21:21:12 +02:00
										 |  |  | #define EXPORT_EARLY_PER_CPU_SYMBOL(_name)			\
 | 
					
						
							|  |  |  | 	EXPORT_PER_CPU_SYMBOL(_name) | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | #define DECLARE_EARLY_PER_CPU(_type, _name)			\
 | 
					
						
							|  |  |  | 	DECLARE_PER_CPU(_type, _name) | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
										
										
											2012-06-11 12:56:45 +03:00
										 |  |  | #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name)		\
 | 
					
						
							|  |  |  | 	DECLARE_PER_CPU_READ_MOSTLY(_type, _name) | 
					
						
							|  |  |  | 
 | 
					
						
							| 
									
										
											  
											
												x86: cleanup early per cpu variables/accesses v4
  * Introduce a new PER_CPU macro called "EARLY_PER_CPU".  This is
    used by some per_cpu variables that are initialized and accessed
    before there are per_cpu areas allocated.
    ["Early" in respect to per_cpu variables is "earlier than the per_cpu
    areas have been setup".]
    This patchset adds these new macros:
	DEFINE_EARLY_PER_CPU(_type, _name, _initvalue)
	EXPORT_EARLY_PER_CPU_SYMBOL(_name)
	DECLARE_EARLY_PER_CPU(_type, _name)
	early_per_cpu_ptr(_name)
	early_per_cpu_map(_name, _idx)
	early_per_cpu(_name, _cpu)
    The DEFINE macro defines the per_cpu variable as well as the early
    map and pointer.  It also initializes the per_cpu variable and map
    elements to "_initvalue".  The early_* macros provide access to
    the initial map (usually setup during system init) and the early
    pointer.  This pointer is initialized to point to the early map
    but is then NULL'ed when the actual per_cpu areas are setup.  After
    that the per_cpu variable is the correct access to the variable.
    The early_per_cpu() macro is not very efficient but does show how to
    access the variable if you have a function that can be called both
    "early" and "late".  It tests the early ptr to be NULL, and if not
    then it's still valid.  Otherwise, the per_cpu variable is used
    instead:
	#define early_per_cpu(_name, _cpu) 			\
		(early_per_cpu_ptr(_name) ?			\
			early_per_cpu_ptr(_name)[_cpu] :	\
			per_cpu(_name, _cpu))
    A better method is to actually check the pointer manually.  In the
    case below, numa_set_node can be called both "early" and "late":
	void __cpuinit numa_set_node(int cpu, int node)
	{
	    int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
	    if (cpu_to_node_map)
		    cpu_to_node_map[cpu] = node;
	    else
		    per_cpu(x86_cpu_to_node_map, cpu) = node;
	}
  * Add a flag "arch_provides_topology_pointers" that indicates pointers
    to topology cpumask_t maps are available.  Otherwise, use the function
    returning the cpumask_t value.  This is useful if cpumask_t set size
    is very large to avoid copying data on to/off of the stack.
  * The coverage of CONFIG_DEBUG_PER_CPU_MAPS has been increased while
    the non-debug case has been optimized a bit.
  * Remove an unreferenced compiler warning in drivers/base/topology.c
  * Clean up #ifdef in setup.c
For inclusion into sched-devel/latest tree.
Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
    +   sched-devel/latest  .../mingo/linux-2.6-sched-devel.git
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
											
										 
											2008-05-12 21:21:12 +02:00
										 |  |  | #define	early_per_cpu(_name, _cpu) per_cpu(_name, _cpu)
 | 
					
						
							|  |  |  | #define	early_per_cpu_ptr(_name) NULL
 | 
					
						
							|  |  |  | /* no early_per_cpu_map() */ | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | #endif	/* !CONFIG_SMP */
 | 
					
						
							|  |  |  | 
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							| 
									
										
										
										
											2008-10-22 22:26:29 -07:00
										 |  |  | #endif /* _ASM_X86_PERCPU_H */
 |