 52eb053b71
			
		
	
	
	52eb053b71
	
	
	
		
			
			This was found by make randconfig If the kernel .text is very large, the .fixup section branches are too far away to be relocated correctly. Use "sethi %hi(label), reg; jmpl reg + %lo(label); %g0" sequence instead of the branch to fix this. There is another case in switch_to() involving a branch, which is fixed similarly. Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			322 lines
		
	
	
	
		
			9.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			322 lines
		
	
	
	
		
			9.4 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| #ifndef __SPARC64_SYSTEM_H
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| #define __SPARC64_SYSTEM_H
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| 
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| #include <asm/ptrace.h>
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| #include <asm/processor.h>
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| #include <asm/visasm.h>
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| 
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| #ifndef __ASSEMBLY__
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| 
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| #include <linux/irqflags.h>
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| 
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| /*
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|  * Sparc (general) CPU types
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|  */
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| enum sparc_cpu {
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|   sun4        = 0x00,
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|   sun4c       = 0x01,
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|   sun4m       = 0x02,
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|   sun4d       = 0x03,
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|   sun4e       = 0x04,
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|   sun4u       = 0x05, /* V8 ploos ploos */
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|   sun_unknown = 0x06,
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|   ap1000      = 0x07, /* almost a sun4m */
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| };
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|                   
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| #define sparc_cpu_model sun4u
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| 
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| /* This cannot ever be a sun4c nor sun4 :) That's just history. */
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| #define ARCH_SUN4C_SUN4 0
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| #define ARCH_SUN4 0
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| 
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| /* These are here in an effort to more fully work around Spitfire Errata
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|  * #51.  Essentially, if a memory barrier occurs soon after a mispredicted
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|  * branch, the chip can stop executing instructions until a trap occurs.
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|  * Therefore, if interrupts are disabled, the chip can hang forever.
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|  *
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|  * It used to be believed that the memory barrier had to be right in the
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|  * delay slot, but a case has been traced recently wherein the memory barrier
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|  * was one instruction after the branch delay slot and the chip still hung.
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|  * The offending sequence was the following in sym_wakeup_done() of the
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|  * sym53c8xx_2 driver:
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|  *
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|  *	call	sym_ccb_from_dsa, 0
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|  *	 movge	%icc, 0, %l0
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|  *	brz,pn	%o0, .LL1303
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|  *	 mov	%o0, %l2
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|  *	membar	#LoadLoad
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|  *
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|  * The branch has to be mispredicted for the bug to occur.  Therefore, we put
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|  * the memory barrier explicitly into a "branch always, predicted taken"
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|  * delay slot to avoid the problem case.
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|  */
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| #define membar_safe(type) \
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| do {	__asm__ __volatile__("ba,pt	%%xcc, 1f\n\t" \
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| 			     " membar	" type "\n" \
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| 			     "1:\n" \
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| 			     : : : "memory"); \
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| } while (0)
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| 
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| #define mb()	\
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| 	membar_safe("#LoadLoad | #LoadStore | #StoreStore | #StoreLoad")
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| #define rmb()	\
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| 	membar_safe("#LoadLoad")
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| #define wmb()	\
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| 	membar_safe("#StoreStore")
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| #define membar_storeload() \
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| 	membar_safe("#StoreLoad")
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| #define membar_storeload_storestore() \
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| 	membar_safe("#StoreLoad | #StoreStore")
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| #define membar_storeload_loadload() \
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| 	membar_safe("#StoreLoad | #LoadLoad")
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| #define membar_storestore_loadstore() \
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| 	membar_safe("#StoreStore | #LoadStore")
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| 
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| #endif
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| 
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| #define nop() 		__asm__ __volatile__ ("nop")
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| 
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| #define read_barrier_depends()		do { } while(0)
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| #define set_mb(__var, __value) \
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| 	do { __var = __value; membar_storeload_storestore(); } while(0)
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| 
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| #ifdef CONFIG_SMP
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| #define smp_mb()	mb()
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| #define smp_rmb()	rmb()
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| #define smp_wmb()	wmb()
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| #define smp_read_barrier_depends()	read_barrier_depends()
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| #else
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| #define smp_mb()	__asm__ __volatile__("":::"memory")
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| #define smp_rmb()	__asm__ __volatile__("":::"memory")
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| #define smp_wmb()	__asm__ __volatile__("":::"memory")
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| #define smp_read_barrier_depends()	do { } while(0)
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| #endif
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| 
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| #define flushi(addr)	__asm__ __volatile__ ("flush %0" : : "r" (addr) : "memory")
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| 
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| #define flushw_all()	__asm__ __volatile__("flushw")
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| 
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| /* Performance counter register access. */
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| #define read_pcr(__p)  __asm__ __volatile__("rd	%%pcr, %0" : "=r" (__p))
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| #define write_pcr(__p) __asm__ __volatile__("wr	%0, 0x0, %%pcr" : : "r" (__p))
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| #define read_pic(__p)  __asm__ __volatile__("rd %%pic, %0" : "=r" (__p))
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| 
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| /* Blackbird errata workaround.  See commentary in
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|  * arch/sparc64/kernel/smp.c:smp_percpu_timer_interrupt()
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|  * for more information.
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|  */
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| #define reset_pic()    						\
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| 	__asm__ __volatile__("ba,pt	%xcc, 99f\n\t"		\
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| 			     ".align	64\n"			\
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| 			  "99:wr	%g0, 0x0, %pic\n\t"	\
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| 			     "rd	%pic, %g0")
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| 
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| #ifndef __ASSEMBLY__
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| 
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| extern void sun_do_break(void);
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| extern int stop_a_enabled;
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| 
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| extern void synchronize_user_stack(void);
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| 
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| extern void __flushw_user(void);
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| #define flushw_user() __flushw_user()
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| 
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| #define flush_user_windows flushw_user
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| #define flush_register_windows flushw_all
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| 
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| /* Don't hold the runqueue lock over context switch */
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| #define __ARCH_WANT_UNLOCKED_CTXSW
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| #define prepare_arch_switch(next)		\
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| do {						\
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| 	flushw_all();				\
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| } while (0)
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| 
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| 	/* See what happens when you design the chip correctly?
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| 	 *
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| 	 * We tell gcc we clobber all non-fixed-usage registers except
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| 	 * for l0/l1.  It will use one for 'next' and the other to hold
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| 	 * the output value of 'last'.  'next' is not referenced again
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| 	 * past the invocation of switch_to in the scheduler, so we need
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| 	 * not preserve it's value.  Hairy, but it lets us remove 2 loads
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| 	 * and 2 stores in this critical code path.  -DaveM
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| 	 */
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| #define switch_to(prev, next, last)					\
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| do {	if (test_thread_flag(TIF_PERFCTR)) {				\
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| 		unsigned long __tmp;					\
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| 		read_pcr(__tmp);					\
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| 		current_thread_info()->pcr_reg = __tmp;			\
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| 		read_pic(__tmp);					\
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| 		current_thread_info()->kernel_cntd0 += (unsigned int)(__tmp);\
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| 		current_thread_info()->kernel_cntd1 += ((__tmp) >> 32);	\
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| 	}								\
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| 	flush_tlb_pending();						\
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| 	save_and_clear_fpu();						\
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| 	/* If you are tempted to conditionalize the following */	\
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| 	/* so that ASI is only written if it changes, think again. */	\
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| 	__asm__ __volatile__("wr %%g0, %0, %%asi"			\
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| 	: : "r" (__thread_flag_byte_ptr(task_thread_info(next))[TI_FLAG_BYTE_CURRENT_DS]));\
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| 	trap_block[current_thread_info()->cpu].thread =			\
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| 		task_thread_info(next);					\
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| 	__asm__ __volatile__(						\
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| 	"mov	%%g4, %%g7\n\t"						\
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| 	"stx	%%i6, [%%sp + 2047 + 0x70]\n\t"				\
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| 	"stx	%%i7, [%%sp + 2047 + 0x78]\n\t"				\
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| 	"rdpr	%%wstate, %%o5\n\t"					\
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| 	"stx	%%o6, [%%g6 + %6]\n\t"					\
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| 	"stb	%%o5, [%%g6 + %5]\n\t"					\
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| 	"rdpr	%%cwp, %%o5\n\t"					\
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| 	"stb	%%o5, [%%g6 + %8]\n\t"					\
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| 	"mov	%4, %%g6\n\t"						\
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| 	"ldub	[%4 + %8], %%g1\n\t"					\
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| 	"wrpr	%%g1, %%cwp\n\t"					\
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| 	"ldx	[%%g6 + %6], %%o6\n\t"					\
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| 	"ldub	[%%g6 + %5], %%o5\n\t"					\
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| 	"ldub	[%%g6 + %7], %%o7\n\t"					\
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| 	"wrpr	%%o5, 0x0, %%wstate\n\t"				\
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| 	"ldx	[%%sp + 2047 + 0x70], %%i6\n\t"				\
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| 	"ldx	[%%sp + 2047 + 0x78], %%i7\n\t"				\
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| 	"ldx	[%%g6 + %9], %%g4\n\t"					\
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| 	"brz,pt %%o7, 1f\n\t"						\
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| 	" mov	%%g7, %0\n\t"						\
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| 	"sethi	%%hi(ret_from_syscall), %%g1\n\t"			\
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| 	"jmpl	%%g1 + %%lo(ret_from_syscall), %%g0\n\t"		\
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| 	" nop\n\t"							\
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| 	"1:\n\t"							\
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| 	: "=&r" (last), "=r" (current), "=r" (current_thread_info_reg),	\
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| 	  "=r" (__local_per_cpu_offset)					\
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| 	: "0" (task_thread_info(next)),					\
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| 	  "i" (TI_WSTATE), "i" (TI_KSP), "i" (TI_NEW_CHILD),            \
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| 	  "i" (TI_CWP), "i" (TI_TASK)					\
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| 	: "cc",								\
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| 	        "g1", "g2", "g3",                   "g7",		\
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| 	        "l1", "l2", "l3", "l4", "l5", "l6", "l7",		\
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| 	  "i0", "i1", "i2", "i3", "i4", "i5",				\
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| 	  "o0", "o1", "o2", "o3", "o4", "o5",       "o7");		\
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| 	/* If you fuck with this, update ret_from_syscall code too. */	\
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| 	if (test_thread_flag(TIF_PERFCTR)) {				\
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| 		write_pcr(current_thread_info()->pcr_reg);		\
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| 		reset_pic();						\
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| 	}								\
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| } while(0)
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| 
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| static inline unsigned long xchg32(__volatile__ unsigned int *m, unsigned int val)
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| {
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| 	unsigned long tmp1, tmp2;
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| 
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| 	__asm__ __volatile__(
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| "	membar		#StoreLoad | #LoadLoad\n"
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| "	mov		%0, %1\n"
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| "1:	lduw		[%4], %2\n"
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| "	cas		[%4], %2, %0\n"
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| "	cmp		%2, %0\n"
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| "	bne,a,pn	%%icc, 1b\n"
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| "	 mov		%1, %0\n"
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| "	membar		#StoreLoad | #StoreStore\n"
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| 	: "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
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| 	: "0" (val), "r" (m)
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| 	: "cc", "memory");
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| 	return val;
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| }
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| 
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| static inline unsigned long xchg64(__volatile__ unsigned long *m, unsigned long val)
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| {
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| 	unsigned long tmp1, tmp2;
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| 
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| 	__asm__ __volatile__(
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| "	membar		#StoreLoad | #LoadLoad\n"
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| "	mov		%0, %1\n"
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| "1:	ldx		[%4], %2\n"
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| "	casx		[%4], %2, %0\n"
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| "	cmp		%2, %0\n"
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| "	bne,a,pn	%%xcc, 1b\n"
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| "	 mov		%1, %0\n"
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| "	membar		#StoreLoad | #StoreStore\n"
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| 	: "=&r" (val), "=&r" (tmp1), "=&r" (tmp2)
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| 	: "0" (val), "r" (m)
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| 	: "cc", "memory");
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| 	return val;
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| }
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| 
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| #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
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| 
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| extern void __xchg_called_with_bad_pointer(void);
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| 
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| static inline unsigned long __xchg(unsigned long x, __volatile__ void * ptr,
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| 				       int size)
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| {
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| 	switch (size) {
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| 	case 4:
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| 		return xchg32(ptr, x);
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| 	case 8:
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| 		return xchg64(ptr, x);
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| 	};
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| 	__xchg_called_with_bad_pointer();
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| 	return x;
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| }
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| 
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| extern void die_if_kernel(char *str, struct pt_regs *regs) __attribute__ ((noreturn));
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| 
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| /* 
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|  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
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|  * store NEW in MEM.  Return the initial value in MEM.  Success is
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|  * indicated by comparing RETURN with OLD.
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|  */
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| 
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| #define __HAVE_ARCH_CMPXCHG 1
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| 
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| static inline unsigned long
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| __cmpxchg_u32(volatile int *m, int old, int new)
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| {
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| 	__asm__ __volatile__("membar #StoreLoad | #LoadLoad\n"
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| 			     "cas [%2], %3, %0\n\t"
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| 			     "membar #StoreLoad | #StoreStore"
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| 			     : "=&r" (new)
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| 			     : "0" (new), "r" (m), "r" (old)
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| 			     : "memory");
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| 
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| 	return new;
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| }
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| 
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| static inline unsigned long
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| __cmpxchg_u64(volatile long *m, unsigned long old, unsigned long new)
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| {
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| 	__asm__ __volatile__("membar #StoreLoad | #LoadLoad\n"
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| 			     "casx [%2], %3, %0\n\t"
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| 			     "membar #StoreLoad | #StoreStore"
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| 			     : "=&r" (new)
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| 			     : "0" (new), "r" (m), "r" (old)
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| 			     : "memory");
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| 
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| 	return new;
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| }
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| 
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| /* This function doesn't exist, so you'll get a linker error
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|    if something tries to do an invalid cmpxchg().  */
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| extern void __cmpxchg_called_with_bad_pointer(void);
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| 
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| static inline unsigned long
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| __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
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| {
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| 	switch (size) {
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| 		case 4:
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| 			return __cmpxchg_u32(ptr, old, new);
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| 		case 8:
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| 			return __cmpxchg_u64(ptr, old, new);
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| 	}
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| 	__cmpxchg_called_with_bad_pointer();
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| 	return old;
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| }
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| 
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| #define cmpxchg(ptr,o,n)						 \
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|   ({									 \
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|      __typeof__(*(ptr)) _o_ = (o);					 \
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|      __typeof__(*(ptr)) _n_ = (n);					 \
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|      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,		 \
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| 				    (unsigned long)_n_, sizeof(*(ptr))); \
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|   })
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| 
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| #endif /* !(__ASSEMBLY__) */
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| 
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| #define arch_align_stack(x) (x)
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| 
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| #endif /* !(__SPARC64_SYSTEM_H) */
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