linux/include/asm-sparc64/spinlock.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

226 lines
4.8 KiB
C

/* spinlock.h: 64-bit Sparc spinlock support.
*
* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
*/
#ifndef __SPARC64_SPINLOCK_H
#define __SPARC64_SPINLOCK_H
#include <linux/config.h>
#include <linux/threads.h> /* For NR_CPUS */
#ifndef __ASSEMBLY__
/* To get debugging spinlocks which detect and catch
* deadlock situations, set CONFIG_DEBUG_SPINLOCK
* and rebuild your kernel.
*/
/* All of these locking primitives are expected to work properly
* even in an RMO memory model, which currently is what the kernel
* runs in.
*
* There is another issue. Because we play games to save cycles
* in the non-contention case, we need to be extra careful about
* branch targets into the "spinning" code. They live in their
* own section, but the newer V9 branches have a shorter range
* than the traditional 32-bit sparc branch variants. The rule
* is that the branches that go into and out of the spinner sections
* must be pre-V9 branches.
*/
#define __raw_spin_is_locked(lp) ((lp)->lock != 0)
#define __raw_spin_unlock_wait(lp) \
do { rmb(); \
} while((lp)->lock)
static inline void __raw_spin_lock(raw_spinlock_t *lock)
{
unsigned long tmp;
__asm__ __volatile__(
"1: ldstub [%1], %0\n"
" membar #StoreLoad | #StoreStore\n"
" brnz,pn %0, 2f\n"
" nop\n"
" .subsection 2\n"
"2: ldub [%1], %0\n"
" membar #LoadLoad\n"
" brnz,pt %0, 2b\n"
" nop\n"
" ba,a,pt %%xcc, 1b\n"
" .previous"
: "=&r" (tmp)
: "r" (lock)
: "memory");
}
static inline int __raw_spin_trylock(raw_spinlock_t *lock)
{
unsigned long result;
__asm__ __volatile__(
" ldstub [%1], %0\n"
" membar #StoreLoad | #StoreStore"
: "=r" (result)
: "r" (lock)
: "memory");
return (result == 0UL);
}
static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{
__asm__ __volatile__(
" membar #StoreStore | #LoadStore\n"
" stb %%g0, [%0]"
: /* No outputs */
: "r" (lock)
: "memory");
}
static inline void __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
{
unsigned long tmp1, tmp2;
__asm__ __volatile__(
"1: ldstub [%2], %0\n"
" membar #StoreLoad | #StoreStore\n"
" brnz,pn %0, 2f\n"
" nop\n"
" .subsection 2\n"
"2: rdpr %%pil, %1\n"
" wrpr %3, %%pil\n"
"3: ldub [%2], %0\n"
" membar #LoadLoad\n"
" brnz,pt %0, 3b\n"
" nop\n"
" ba,pt %%xcc, 1b\n"
" wrpr %1, %%pil\n"
" .previous"
: "=&r" (tmp1), "=&r" (tmp2)
: "r"(lock), "r"(flags)
: "memory");
}
/* Multi-reader locks, these are much saner than the 32-bit Sparc ones... */
static void inline __read_lock(raw_rwlock_t *lock)
{
unsigned long tmp1, tmp2;
__asm__ __volatile__ (
"1: ldsw [%2], %0\n"
" brlz,pn %0, 2f\n"
"4: add %0, 1, %1\n"
" cas [%2], %0, %1\n"
" cmp %0, %1\n"
" membar #StoreLoad | #StoreStore\n"
" bne,pn %%icc, 1b\n"
" nop\n"
" .subsection 2\n"
"2: ldsw [%2], %0\n"
" membar #LoadLoad\n"
" brlz,pt %0, 2b\n"
" nop\n"
" ba,a,pt %%xcc, 4b\n"
" .previous"
: "=&r" (tmp1), "=&r" (tmp2)
: "r" (lock)
: "memory");
}
static void inline __read_unlock(raw_rwlock_t *lock)
{
unsigned long tmp1, tmp2;
__asm__ __volatile__(
" membar #StoreLoad | #LoadLoad\n"
"1: lduw [%2], %0\n"
" sub %0, 1, %1\n"
" cas [%2], %0, %1\n"
" cmp %0, %1\n"
" bne,pn %%xcc, 1b\n"
" nop"
: "=&r" (tmp1), "=&r" (tmp2)
: "r" (lock)
: "memory");
}
static void inline __write_lock(raw_rwlock_t *lock)
{
unsigned long mask, tmp1, tmp2;
mask = 0x80000000UL;
__asm__ __volatile__(
"1: lduw [%2], %0\n"
" brnz,pn %0, 2f\n"
"4: or %0, %3, %1\n"
" cas [%2], %0, %1\n"
" cmp %0, %1\n"
" membar #StoreLoad | #StoreStore\n"
" bne,pn %%icc, 1b\n"
" nop\n"
" .subsection 2\n"
"2: lduw [%2], %0\n"
" membar #LoadLoad\n"
" brnz,pt %0, 2b\n"
" nop\n"
" ba,a,pt %%xcc, 4b\n"
" .previous"
: "=&r" (tmp1), "=&r" (tmp2)
: "r" (lock), "r" (mask)
: "memory");
}
static void inline __write_unlock(raw_rwlock_t *lock)
{
__asm__ __volatile__(
" membar #LoadStore | #StoreStore\n"
" stw %%g0, [%0]"
: /* no outputs */
: "r" (lock)
: "memory");
}
static int inline __write_trylock(raw_rwlock_t *lock)
{
unsigned long mask, tmp1, tmp2, result;
mask = 0x80000000UL;
__asm__ __volatile__(
" mov 0, %2\n"
"1: lduw [%3], %0\n"
" brnz,pn %0, 2f\n"
" or %0, %4, %1\n"
" cas [%3], %0, %1\n"
" cmp %0, %1\n"
" membar #StoreLoad | #StoreStore\n"
" bne,pn %%icc, 1b\n"
" nop\n"
" mov 1, %2\n"
"2:"
: "=&r" (tmp1), "=&r" (tmp2), "=&r" (result)
: "r" (lock), "r" (mask)
: "memory");
return result;
}
#define __raw_read_lock(p) __read_lock(p)
#define __raw_read_unlock(p) __read_unlock(p)
#define __raw_write_lock(p) __write_lock(p)
#define __raw_write_unlock(p) __write_unlock(p)
#define __raw_write_trylock(p) __write_trylock(p)
#define __raw_read_trylock(lock) generic__raw_read_trylock(lock)
#define __raw_read_can_lock(rw) (!((rw)->lock & 0x80000000UL))
#define __raw_write_can_lock(rw) (!(rw)->lock)
#endif /* !(__ASSEMBLY__) */
#endif /* !(__SPARC64_SPINLOCK_H) */