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linux-next/include/asm-parisc/system.h
Ingo Molnar fb1c8f93d8 [PATCH] spinlock consolidation
This patch (written by me and also containing many suggestions of Arjan van
de Ven) does a major cleanup of the spinlock code.  It does the following
things:

 - consolidates and enhances the spinlock/rwlock debugging code

 - simplifies the asm/spinlock.h files

 - encapsulates the raw spinlock type and moves generic spinlock
   features (such as ->break_lock) into the generic code.

 - cleans up the spinlock code hierarchy to get rid of the spaghetti.

Most notably there's now only a single variant of the debugging code,
located in lib/spinlock_debug.c.  (previously we had one SMP debugging
variant per architecture, plus a separate generic one for UP builds)

Also, i've enhanced the rwlock debugging facility, it will now track
write-owners.  There is new spinlock-owner/CPU-tracking on SMP builds too.
All locks have lockup detection now, which will work for both soft and hard
spin/rwlock lockups.

The arch-level include files now only contain the minimally necessary
subset of the spinlock code - all the rest that can be generalized now
lives in the generic headers:

 include/asm-i386/spinlock_types.h       |   16
 include/asm-x86_64/spinlock_types.h     |   16

I have also split up the various spinlock variants into separate files,
making it easier to see which does what. The new layout is:

   SMP                         |  UP
   ----------------------------|-----------------------------------
   asm/spinlock_types_smp.h    |  linux/spinlock_types_up.h
   linux/spinlock_types.h      |  linux/spinlock_types.h
   asm/spinlock_smp.h          |  linux/spinlock_up.h
   linux/spinlock_api_smp.h    |  linux/spinlock_api_up.h
   linux/spinlock.h            |  linux/spinlock.h

/*
 * here's the role of the various spinlock/rwlock related include files:
 *
 * on SMP builds:
 *
 *  asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
 *                        initializers
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  asm/spinlock.h:       contains the __raw_spin_*()/etc. lowlevel
 *                        implementations, mostly inline assembly code
 *
 *   (also included on UP-debug builds:)
 *
 *  linux/spinlock_api_smp.h:
 *                        contains the prototypes for the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 *
 * on UP builds:
 *
 *  linux/spinlock_type_up.h:
 *                        contains the generic, simplified UP spinlock type.
 *                        (which is an empty structure on non-debug builds)
 *
 *  linux/spinlock_types.h:
 *                        defines the generic type and initializers
 *
 *  linux/spinlock_up.h:
 *                        contains the __raw_spin_*()/etc. version of UP
 *                        builds. (which are NOPs on non-debug, non-preempt
 *                        builds)
 *
 *   (included on UP-non-debug builds:)
 *
 *  linux/spinlock_api_up.h:
 *                        builds the _spin_*() APIs.
 *
 *  linux/spinlock.h:     builds the final spin_*() APIs.
 */

All SMP and UP architectures are converted by this patch.

arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via
crosscompilers.  m32r, mips, sh, sparc, have not been tested yet, but should
be mostly fine.

From: Grant Grundler <grundler@parisc-linux.org>

  Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU).
  Builds 32-bit SMP kernel (not booted or tested).  I did not try to build
  non-SMP kernels.  That should be trivial to fix up later if necessary.

  I converted bit ops atomic_hash lock to raw_spinlock_t.  Doing so avoids
  some ugly nesting of linux/*.h and asm/*.h files.  Those particular locks
  are well tested and contained entirely inside arch specific code.  I do NOT
  expect any new issues to arise with them.

 If someone does ever need to use debug/metrics with them, then they will
  need to unravel this hairball between spinlocks, atomic ops, and bit ops
  that exist only because parisc has exactly one atomic instruction: LDCW
  (load and clear word).

From: "Luck, Tony" <tony.luck@intel.com>

   ia64 fix

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjanv@infradead.org>
Signed-off-by: Grant Grundler <grundler@parisc-linux.org>
Cc: Matthew Wilcox <willy@debian.org>
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se>
Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10 10:06:21 -07:00

189 lines
5.4 KiB
C

#ifndef __PARISC_SYSTEM_H
#define __PARISC_SYSTEM_H
#include <linux/config.h>
#include <asm/psw.h>
/* The program status word as bitfields. */
struct pa_psw {
unsigned int y:1;
unsigned int z:1;
unsigned int rv:2;
unsigned int w:1;
unsigned int e:1;
unsigned int s:1;
unsigned int t:1;
unsigned int h:1;
unsigned int l:1;
unsigned int n:1;
unsigned int x:1;
unsigned int b:1;
unsigned int c:1;
unsigned int v:1;
unsigned int m:1;
unsigned int cb:8;
unsigned int o:1;
unsigned int g:1;
unsigned int f:1;
unsigned int r:1;
unsigned int q:1;
unsigned int p:1;
unsigned int d:1;
unsigned int i:1;
};
#ifdef __LP64__
#define pa_psw(task) ((struct pa_psw *) ((char *) (task) + TASK_PT_PSW + 4))
#else
#define pa_psw(task) ((struct pa_psw *) ((char *) (task) + TASK_PT_PSW))
#endif
struct task_struct;
extern struct task_struct *_switch_to(struct task_struct *, struct task_struct *);
#define switch_to(prev, next, last) do { \
(last) = _switch_to(prev, next); \
} while(0)
/* interrupt control */
#define local_save_flags(x) __asm__ __volatile__("ssm 0, %0" : "=r" (x) : : "memory")
#define local_irq_disable() __asm__ __volatile__("rsm %0,%%r0\n" : : "i" (PSW_I) : "memory" )
#define local_irq_enable() __asm__ __volatile__("ssm %0,%%r0\n" : : "i" (PSW_I) : "memory" )
#define local_irq_save(x) \
__asm__ __volatile__("rsm %1,%0" : "=r" (x) :"i" (PSW_I) : "memory" )
#define local_irq_restore(x) \
__asm__ __volatile__("mtsm %0" : : "r" (x) : "memory" )
#define irqs_disabled() \
({ \
unsigned long flags; \
local_save_flags(flags); \
(flags & PSW_I) == 0; \
})
#define mfctl(reg) ({ \
unsigned long cr; \
__asm__ __volatile__( \
"mfctl " #reg ",%0" : \
"=r" (cr) \
); \
cr; \
})
#define mtctl(gr, cr) \
__asm__ __volatile__("mtctl %0,%1" \
: /* no outputs */ \
: "r" (gr), "i" (cr) : "memory")
/* these are here to de-mystefy the calling code, and to provide hooks */
/* which I needed for debugging EIEM problems -PB */
#define get_eiem() mfctl(15)
static inline void set_eiem(unsigned long val)
{
mtctl(val, 15);
}
#define mfsp(reg) ({ \
unsigned long cr; \
__asm__ __volatile__( \
"mfsp " #reg ",%0" : \
"=r" (cr) \
); \
cr; \
})
#define mtsp(gr, cr) \
__asm__ __volatile__("mtsp %0,%1" \
: /* no outputs */ \
: "r" (gr), "i" (cr) : "memory")
/*
** This is simply the barrier() macro from linux/kernel.h but when serial.c
** uses tqueue.h uses smp_mb() defined using barrier(), linux/kernel.h
** hasn't yet been included yet so it fails, thus repeating the macro here.
**
** PA-RISC architecture allows for weakly ordered memory accesses although
** none of the processors use it. There is a strong ordered bit that is
** set in the O-bit of the page directory entry. Operating systems that
** can not tolerate out of order accesses should set this bit when mapping
** pages. The O-bit of the PSW should also be set to 1 (I don't believe any
** of the processor implemented the PSW O-bit). The PCX-W ERS states that
** the TLB O-bit is not implemented so the page directory does not need to
** have the O-bit set when mapping pages (section 3.1). This section also
** states that the PSW Y, Z, G, and O bits are not implemented.
** So it looks like nothing needs to be done for parisc-linux (yet).
** (thanks to chada for the above comment -ggg)
**
** The __asm__ op below simple prevents gcc/ld from reordering
** instructions across the mb() "call".
*/
#define mb() __asm__ __volatile__("":::"memory") /* barrier() */
#define rmb() mb()
#define wmb() mb()
#define smp_mb() mb()
#define smp_rmb() mb()
#define smp_wmb() mb()
#define smp_read_barrier_depends() do { } while(0)
#define read_barrier_depends() do { } while(0)
#define set_mb(var, value) do { var = value; mb(); } while (0)
#define set_wmb(var, value) do { var = value; wmb(); } while (0)
/* LDCW, the only atomic read-write operation PA-RISC has. *sigh*. */
#define __ldcw(a) ({ \
unsigned __ret; \
__asm__ __volatile__("ldcw 0(%1),%0" : "=r" (__ret) : "r" (a)); \
__ret; \
})
/* Because kmalloc only guarantees 8-byte alignment for kmalloc'd data,
and GCC only guarantees 8-byte alignment for stack locals, we can't
be assured of 16-byte alignment for atomic lock data even if we
specify "__attribute ((aligned(16)))" in the type declaration. So,
we use a struct containing an array of four ints for the atomic lock
type and dynamically select the 16-byte aligned int from the array
for the semaphore. */
#define __PA_LDCW_ALIGNMENT 16
#define __ldcw_align(a) ({ \
unsigned long __ret = (unsigned long) &(a)->lock[0]; \
__ret = (__ret + __PA_LDCW_ALIGNMENT - 1) & ~(__PA_LDCW_ALIGNMENT - 1); \
(volatile unsigned int *) __ret; \
})
#ifdef CONFIG_SMP
# define __lock_aligned __attribute__((__section__(".data.lock_aligned")))
#endif
#define KERNEL_START (0x10100000 - 0x1000)
/* This is for the serialisation of PxTLB broadcasts. At least on the
* N class systems, only one PxTLB inter processor broadcast can be
* active at any one time on the Merced bus. This tlb purge
* synchronisation is fairly lightweight and harmless so we activate
* it on all SMP systems not just the N class. */
#ifdef CONFIG_SMP
extern spinlock_t pa_tlb_lock;
#define purge_tlb_start(x) spin_lock(&pa_tlb_lock)
#define purge_tlb_end(x) spin_unlock(&pa_tlb_lock)
#else
#define purge_tlb_start(x) do { } while(0)
#define purge_tlb_end(x) do { } while (0)
#endif
#define arch_align_stack(x) (x)
#endif