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linux/arch/arm/include/asm/processor.h

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Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
[ARM] move include/asm-arm to arch/arm/include/asm Move platform independent header files to arch/arm/include/asm, leaving those in asm/arch* and asm/plat* alone. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-02 09:55:55 +00:00
* arch/arm/include/asm/processor.h
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
*
* Copyright (C) 1995-1999 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_ARM_PROCESSOR_H
#define __ASM_ARM_PROCESSOR_H
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter").
*/
#define current_text_addr() ({ __label__ _l; _l: &&_l;})
#ifdef __KERNEL__
#include <asm/ptrace.h>
#include <asm/types.h>
aout: move STACK_TOP[_MAX] to asm/processor.h Move STACK_TOP[_MAX] out of asm/a.out.h and into asm/processor.h as they're required whether or not A.OUT format is available. Signed-off-by: David Howells <dhowells@redhat.com> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-08 12:19:26 +00:00
#ifdef __KERNEL__
#define STACK_TOP ((current->personality == PER_LINUX_32BIT) ? \
TASK_SIZE : TASK_SIZE_26)
#define STACK_TOP_MAX TASK_SIZE
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
union debug_insn {
u32 arm;
u16 thumb;
};
struct debug_entry {
u32 address;
union debug_insn insn;
};
struct debug_info {
int nsaved;
struct debug_entry bp[2];
};
struct thread_struct {
/* fault info */
unsigned long address;
unsigned long trap_no;
unsigned long error_code;
/* debugging */
struct debug_info debug;
};
#define INIT_THREAD { }
[ARM] start_thread fixup for nommu mode This patch supports start_thread in nommu mode which requires the base index register. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-13 21:04:17 +00:00
#ifdef CONFIG_MMU
#define nommu_start_thread(regs) do { } while (0)
#else
#define nommu_start_thread(regs) regs->ARM_r10 = current->mm->start_data
#endif
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#define start_thread(regs,pc,sp) \
({ \
unsigned long *stack = (unsigned long *)sp; \
set_fs(USER_DS); \
memzero(regs->uregs, sizeof(regs->uregs)); \
if (current->personality & ADDR_LIMIT_32BIT) \
regs->ARM_cpsr = USR_MODE; \
else \
regs->ARM_cpsr = USR26_MODE; \
if (elf_hwcap & HWCAP_THUMB && pc & 1) \
regs->ARM_cpsr |= PSR_T_BIT; \
regs->ARM_pc = pc & ~1; /* pc */ \
regs->ARM_sp = sp; /* sp */ \
regs->ARM_r2 = stack[2]; /* r2 (envp) */ \
regs->ARM_r1 = stack[1]; /* r1 (argv) */ \
regs->ARM_r0 = stack[0]; /* r0 (argc) */ \
[ARM] start_thread fixup for nommu mode This patch supports start_thread in nommu mode which requires the base index register. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-01-13 21:04:17 +00:00
nommu_start_thread(regs); \
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
})
/* Forward declaration, a strange C thing */
struct task_struct;
/* Free all resources held by a thread. */
extern void release_thread(struct task_struct *);
/* Prepare to copy thread state - unlazy all lazy status */
#define prepare_to_copy(tsk) do { } while (0)
unsigned long get_wchan(struct task_struct *p);
#define cpu_relax() barrier()
/*
* Create a new kernel thread
*/
extern int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags);
[PATCH] arm: task_pt_regs() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:05:57 +00:00
#define task_pt_regs(p) \
[PATCH] arm: task_stack_page() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:05:58 +00:00
((struct pt_regs *)(THREAD_START_SP + task_stack_page(p)) - 1)
[PATCH] arm: task_pt_regs() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-12 09:05:57 +00:00
#define KSTK_EIP(tsk) task_pt_regs(tsk)->ARM_pc
#define KSTK_ESP(tsk) task_pt_regs(tsk)->ARM_sp
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
/*
* Prefetching support - only ARMv5.
*/
#if __LINUX_ARM_ARCH__ >= 5
#define ARCH_HAS_PREFETCH
[ARM] 4016/1: prefetch macro is wrong wrt gcc's "delete-null-pointer-checks" optimization The gcc manual says: |`-fdelete-null-pointer-checks' | Use global dataflow analysis to identify and eliminate useless | checks for null pointers. The compiler assumes that dereferencing | a null pointer would have halted the program. If a pointer is | checked after it has already been dereferenced, it cannot be null. | Enabled at levels `-O2', `-O3', `-Os'. Now the problem can be seen with this test case: #include <linux/prefetch.h> extern void bar(char *x); void foo(char *x) { prefetch(x); if (x) bar(x); } Because the constraint to the inline asm used in the prefetch() macro is a memory operand, gcc assumes that the asm code does dereference the pointer and the delete-null-pointer-checks optimization kicks in. Inspection of generated assembly for the above example shows that bar() is indeed called unconditionally without any test on the value of x. Of course in the prefetch case there is no real dereference and it cannot be assumed that a null pointer would have been caught at that point. This causes kernel oopses with constructs like hlist_for_each_entry() where the list's 'next' content is prefetched before the pointer is tested against NULL, and only when gcc feels like applying this optimization which doesn't happen all the time with more complex code. It appears that the way to prevent delete-null-pointer-checks optimization to occur in this case is to make prefetch() into a static inline function instead of a macro. At least this is what is done on x86_64 where a similar inline asm memory operand is used (I presume they would have seen the same problem if it didn't work) and resulting code for the above example confirms that. An alternative would consist of replacing the memory operand by a register operand containing the pointer, and use the addressing mode explicitly in the asm template. But that would be less optimal than an offsettable memory reference. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-12-13 17:39:26 +00:00
static inline void prefetch(const void *ptr)
{
__asm__ __volatile__(
[ARM] 5196/1: fix inline asm constraints for preload With gcc 4.3 and later, a pointer that has already been dereferenced is assumed not to be null since it should have caused a segmentation fault otherwise, hence any subsequent test against NULL is optimized away. Current inline asm constraint used in the implementation of prefetch() makes gcc believe that the pointer is dereferenced even though the PLD instruction does not load any data and does not cause a segmentation fault on null pointers, which causes all sorts of interesting results when reaching the end of a linked lists for example. Let's use a better constraint to properly represent the actual usage of the pointer value. Problem reported by Chris Steel. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-12 21:10:59 +00:00
"pld\t%a0"
[ARM] 4016/1: prefetch macro is wrong wrt gcc's "delete-null-pointer-checks" optimization The gcc manual says: |`-fdelete-null-pointer-checks' | Use global dataflow analysis to identify and eliminate useless | checks for null pointers. The compiler assumes that dereferencing | a null pointer would have halted the program. If a pointer is | checked after it has already been dereferenced, it cannot be null. | Enabled at levels `-O2', `-O3', `-Os'. Now the problem can be seen with this test case: #include <linux/prefetch.h> extern void bar(char *x); void foo(char *x) { prefetch(x); if (x) bar(x); } Because the constraint to the inline asm used in the prefetch() macro is a memory operand, gcc assumes that the asm code does dereference the pointer and the delete-null-pointer-checks optimization kicks in. Inspection of generated assembly for the above example shows that bar() is indeed called unconditionally without any test on the value of x. Of course in the prefetch case there is no real dereference and it cannot be assumed that a null pointer would have been caught at that point. This causes kernel oopses with constructs like hlist_for_each_entry() where the list's 'next' content is prefetched before the pointer is tested against NULL, and only when gcc feels like applying this optimization which doesn't happen all the time with more complex code. It appears that the way to prevent delete-null-pointer-checks optimization to occur in this case is to make prefetch() into a static inline function instead of a macro. At least this is what is done on x86_64 where a similar inline asm memory operand is used (I presume they would have seen the same problem if it didn't work) and resulting code for the above example confirms that. An alternative would consist of replacing the memory operand by a register operand containing the pointer, and use the addressing mode explicitly in the asm template. But that would be less optimal than an offsettable memory reference. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-12-13 17:39:26 +00:00
:
[ARM] 5196/1: fix inline asm constraints for preload With gcc 4.3 and later, a pointer that has already been dereferenced is assumed not to be null since it should have caused a segmentation fault otherwise, hence any subsequent test against NULL is optimized away. Current inline asm constraint used in the implementation of prefetch() makes gcc believe that the pointer is dereferenced even though the PLD instruction does not load any data and does not cause a segmentation fault on null pointers, which causes all sorts of interesting results when reaching the end of a linked lists for example. Let's use a better constraint to properly represent the actual usage of the pointer value. Problem reported by Chris Steel. Signed-off-by: Nicolas Pitre <nico@marvell.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2008-08-12 21:10:59 +00:00
: "p" (ptr)
[ARM] 4016/1: prefetch macro is wrong wrt gcc's "delete-null-pointer-checks" optimization The gcc manual says: |`-fdelete-null-pointer-checks' | Use global dataflow analysis to identify and eliminate useless | checks for null pointers. The compiler assumes that dereferencing | a null pointer would have halted the program. If a pointer is | checked after it has already been dereferenced, it cannot be null. | Enabled at levels `-O2', `-O3', `-Os'. Now the problem can be seen with this test case: #include <linux/prefetch.h> extern void bar(char *x); void foo(char *x) { prefetch(x); if (x) bar(x); } Because the constraint to the inline asm used in the prefetch() macro is a memory operand, gcc assumes that the asm code does dereference the pointer and the delete-null-pointer-checks optimization kicks in. Inspection of generated assembly for the above example shows that bar() is indeed called unconditionally without any test on the value of x. Of course in the prefetch case there is no real dereference and it cannot be assumed that a null pointer would have been caught at that point. This causes kernel oopses with constructs like hlist_for_each_entry() where the list's 'next' content is prefetched before the pointer is tested against NULL, and only when gcc feels like applying this optimization which doesn't happen all the time with more complex code. It appears that the way to prevent delete-null-pointer-checks optimization to occur in this case is to make prefetch() into a static inline function instead of a macro. At least this is what is done on x86_64 where a similar inline asm memory operand is used (I presume they would have seen the same problem if it didn't work) and resulting code for the above example confirms that. An alternative would consist of replacing the memory operand by a register operand containing the pointer, and use the addressing mode explicitly in the asm template. But that would be less optimal than an offsettable memory reference. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-12-13 17:39:26 +00:00
: "cc");
}
Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
2005-04-16 22:20:36 +00:00
#define ARCH_HAS_PREFETCHW
#define prefetchw(ptr) prefetch(ptr)
#define ARCH_HAS_SPINLOCK_PREFETCH
#define spin_lock_prefetch(x) do { } while (0)
#endif
#endif
#endif /* __ASM_ARM_PROCESSOR_H */
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