linux/include/asm-powerpc/thread_info.h
David Gibson 6cb7bfebb1 [PATCH] powerpc: Merge thread_info.h
Merge ppc32 and ppc64 versions of thread_info.h.  They were pretty
similar already, the chief changes are:

	- Instead of inline asm to implement current_thread_info(),
which needs to be different for ppc32 and ppc64, we use C with an
asm("r1") register variable.  gcc turns it into the same asm as we
used to have for both platforms.
	- We replace ppc32's 'local_flags' with the ppc64
'syscall_noerror' field.  The noerror flag was in fact the only thing
in the local_flags field anyway, so the ppc64 approach is simpler, and
means we only need a load-immediate/store instead of load/mask/store
when clearing the flag.
	- In readiness for 64k pages, when THREAD_SIZE will be less
than a page, ppc64 used kmalloc() rather than get_free_pages() to
allocate the kernel stack.  With this patch we do the same for ppc32,
since there's no strong reason not to.
	- For ppc64, we no longer export THREAD_SHIFT and THREAD_SIZE
via asm-offsets, thread_info.h can now be safely included in asm, as
on ppc32.

Built and booted on G4 Powerbook (ARCH=ppc and ARCH=powerpc) and
Power5 (ARCH=ppc64 and ARCH=powerpc).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-10-21 22:47:23 +10:00

135 lines
3.9 KiB
C

/* thread_info.h: PowerPC low-level thread information
* adapted from the i386 version by Paul Mackerras
*
* Copyright (C) 2002 David Howells (dhowells@redhat.com)
* - Incorporating suggestions made by Linus Torvalds and Dave Miller
*/
#ifndef _ASM_POWERPC_THREAD_INFO_H
#define _ASM_POWERPC_THREAD_INFO_H
#ifdef __KERNEL__
/* We have 8k stacks on ppc32 and 16k on ppc64 */
#ifdef CONFIG_PPC64
#define THREAD_SHIFT 14
#else
#define THREAD_SHIFT 13
#endif
#define THREAD_SIZE (1 << THREAD_SHIFT)
#ifndef __ASSEMBLY__
#include <linux/config.h>
#include <linux/cache.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <linux/stringify.h>
/*
* low level task data.
*/
struct thread_info {
struct task_struct *task; /* main task structure */
struct exec_domain *exec_domain; /* execution domain */
int cpu; /* cpu we're on */
int preempt_count; /* 0 => preemptable,
<0 => BUG */
struct restart_block restart_block;
/* set by force_successful_syscall_return */
unsigned char syscall_noerror;
/* low level flags - has atomic operations done on it */
unsigned long flags ____cacheline_aligned_in_smp;
};
/*
* macros/functions for gaining access to the thread information structure
*
* preempt_count needs to be 1 initially, until the scheduler is functional.
*/
#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \
.exec_domain = &default_exec_domain, \
.cpu = 0, \
.preempt_count = 1, \
.restart_block = { \
.fn = do_no_restart_syscall, \
}, \
.flags = 0, \
}
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
/* thread information allocation */
#ifdef CONFIG_DEBUG_STACK_USAGE
#define alloc_thread_info(tsk) \
({ \
struct thread_info *ret; \
\
ret = kmalloc(THREAD_SIZE, GFP_KERNEL); \
if (ret) \
memset(ret, 0, THREAD_SIZE); \
ret; \
})
#else
#define alloc_thread_info(tsk) kmalloc(THREAD_SIZE, GFP_KERNEL)
#endif
#define free_thread_info(ti) kfree(ti)
#define get_thread_info(ti) get_task_struct((ti)->task)
#define put_thread_info(ti) put_task_struct((ti)->task)
/* how to get the thread information struct from C */
static inline struct thread_info *current_thread_info(void)
{
register unsigned long sp asm("r1");
/* gcc4, at least, is smart enough to turn this into a single
* rlwinm for ppc32 and clrrdi for ppc64 */
return (struct thread_info *)(sp & ~(THREAD_SIZE-1));
}
#endif /* __ASSEMBLY__ */
#define PREEMPT_ACTIVE 0x10000000
/*
* thread information flag bit numbers
*/
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_NOTIFY_RESUME 1 /* resumption notification requested */
#define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_POLLING_NRFLAG 4 /* true if poll_idle() is polling
TIF_NEED_RESCHED */
#define TIF_32BIT 5 /* 32 bit binary */
/* #define SPARE 6 */
#define TIF_ABI_PENDING 7 /* 32/64 bit switch needed */
#define TIF_SYSCALL_AUDIT 8 /* syscall auditing active */
#define TIF_SINGLESTEP 9 /* singlestepping active */
#define TIF_MEMDIE 10
#define TIF_SECCOMP 11 /* secure computing */
/* as above, but as bit values */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
#define _TIF_32BIT (1<<TIF_32BIT)
/* #define _SPARE (1<<SPARE) */
#define _TIF_ABI_PENDING (1<<TIF_ABI_PENDING)
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_SINGLESTEP (1<<TIF_SINGLESTEP)
#define _TIF_SECCOMP (1<<TIF_SECCOMP)
#define _TIF_SYSCALL_T_OR_A (_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SECCOMP)
#define _TIF_USER_WORK_MASK (_TIF_NOTIFY_RESUME | _TIF_SIGPENDING | \
_TIF_NEED_RESCHED)
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_THREAD_INFO_H */