 b3901d54dc
			
		
	
	
	b3901d54dc
	
	
	
		
			
			The patch adds support for thread creation and context switching. The context switching CPU specific code is introduced with the CPU support patch (part of the arch/arm64/mm/proc.S file). AArch64 supports ASID-tagged TLBs and the ASID can be either 8 or 16-bit wide (detectable via the ID_AA64AFR0_EL1 register). Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Olof Johansson <olof@lixom.net> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Arnd Bergmann <arnd@arndb.de>
		
			
				
	
	
		
			127 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			127 lines
		
	
	
	
		
			3.7 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Based on arch/arm/include/asm/thread_info.h
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|  *
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|  * Copyright (C) 2002 Russell King.
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|  * Copyright (C) 2012 ARM Ltd.
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
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|  */
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| #ifndef __ASM_THREAD_INFO_H
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| #define __ASM_THREAD_INFO_H
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| 
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| #ifdef __KERNEL__
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| 
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| #include <linux/compiler.h>
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| 
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| #ifndef CONFIG_ARM64_64K_PAGES
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| #define THREAD_SIZE_ORDER	1
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| #endif
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| 
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| #define THREAD_SIZE		8192
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| #define THREAD_START_SP		(THREAD_SIZE - 16)
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| 
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| #ifndef __ASSEMBLY__
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| 
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| struct task_struct;
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| struct exec_domain;
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| 
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| #include <asm/types.h>
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| 
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| typedef unsigned long mm_segment_t;
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| 
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| /*
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|  * low level task data that entry.S needs immediate access to.
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|  * __switch_to() assumes cpu_context follows immediately after cpu_domain.
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|  */
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| struct thread_info {
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| 	unsigned long		flags;		/* low level flags */
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| 	mm_segment_t		addr_limit;	/* address limit */
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| 	struct task_struct	*task;		/* main task structure */
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| 	struct exec_domain	*exec_domain;	/* execution domain */
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| 	struct restart_block	restart_block;
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| 	int			preempt_count;	/* 0 => preemptable, <0 => bug */
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| 	int			cpu;		/* cpu */
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| };
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| 
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| #define INIT_THREAD_INFO(tsk)						\
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| {									\
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| 	.task		= &tsk,						\
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| 	.exec_domain	= &default_exec_domain,				\
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| 	.flags		= 0,						\
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| 	.preempt_count	= INIT_PREEMPT_COUNT,				\
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| 	.addr_limit	= KERNEL_DS,					\
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| 	.restart_block	= {						\
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| 		.fn	= do_no_restart_syscall,			\
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| 	},								\
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| }
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| 
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| #define init_thread_info	(init_thread_union.thread_info)
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| #define init_stack		(init_thread_union.stack)
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| 
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| /*
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|  * how to get the thread information struct from C
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|  */
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| static inline struct thread_info *current_thread_info(void) __attribute_const__;
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| 
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| static inline struct thread_info *current_thread_info(void)
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| {
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| 	register unsigned long sp asm ("sp");
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| 	return (struct thread_info *)(sp & ~(THREAD_SIZE - 1));
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| }
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| 
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| #define thread_saved_pc(tsk)	\
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| 	((unsigned long)(tsk->thread.cpu_context.pc))
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| #define thread_saved_sp(tsk)	\
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| 	((unsigned long)(tsk->thread.cpu_context.sp))
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| #define thread_saved_fp(tsk)	\
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| 	((unsigned long)(tsk->thread.cpu_context.fp))
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| 
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| #endif
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| 
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| /*
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|  * We use bit 30 of the preempt_count to indicate that kernel
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|  * preemption is occurring.  See <asm/hardirq.h>.
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|  */
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| #define PREEMPT_ACTIVE	0x40000000
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| 
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| /*
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|  * thread information flags:
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|  *  TIF_SYSCALL_TRACE	- syscall trace active
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|  *  TIF_SIGPENDING	- signal pending
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|  *  TIF_NEED_RESCHED	- rescheduling necessary
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|  *  TIF_NOTIFY_RESUME	- callback before returning to user
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|  *  TIF_USEDFPU		- FPU was used by this task this quantum (SMP)
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|  *  TIF_POLLING_NRFLAG	- true if poll_idle() is polling TIF_NEED_RESCHED
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|  */
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| #define TIF_SIGPENDING		0
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| #define TIF_NEED_RESCHED	1
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| #define TIF_NOTIFY_RESUME	2	/* callback before returning to user */
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| #define TIF_SYSCALL_TRACE	8
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| #define TIF_POLLING_NRFLAG	16
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| #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
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| #define TIF_FREEZE		19
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| #define TIF_RESTORE_SIGMASK	20
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| #define TIF_SINGLESTEP		21
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| #define TIF_32BIT		22	/* 32bit process */
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| #define TIF_SWITCH_MM		23	/* deferred switch_mm */
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| 
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| #define _TIF_SIGPENDING		(1 << TIF_SIGPENDING)
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| #define _TIF_NEED_RESCHED	(1 << TIF_NEED_RESCHED)
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| #define _TIF_NOTIFY_RESUME	(1 << TIF_NOTIFY_RESUME)
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| #define _TIF_32BIT		(1 << TIF_32BIT)
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| 
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| #define _TIF_WORK_MASK		(_TIF_NEED_RESCHED | _TIF_SIGPENDING | \
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| 				 _TIF_NOTIFY_RESUME)
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| 
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| #endif /* __KERNEL__ */
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| #endif /* __ASM_THREAD_INFO_H */
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