[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>
diff --git a/arch/alpha/kernel/alpha_ksyms.c b/arch/alpha/kernel/alpha_ksyms.c
index fc5ef90..24ae9a3 100644
--- a/arch/alpha/kernel/alpha_ksyms.c
+++ b/arch/alpha/kernel/alpha_ksyms.c
@@ -185,15 +185,6 @@
EXPORT_SYMBOL(smp_call_function);
EXPORT_SYMBOL(smp_call_function_on_cpu);
EXPORT_SYMBOL(_atomic_dec_and_lock);
-#ifdef CONFIG_DEBUG_SPINLOCK
-EXPORT_SYMBOL(_raw_spin_unlock);
-EXPORT_SYMBOL(debug_spin_lock);
-EXPORT_SYMBOL(debug_spin_trylock);
-#endif
-#ifdef CONFIG_DEBUG_RWLOCK
-EXPORT_SYMBOL(_raw_write_lock);
-EXPORT_SYMBOL(_raw_read_lock);
-#endif
EXPORT_SYMBOL(cpu_present_mask);
#endif /* CONFIG_SMP */
diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
index e211aa7..da0be34 100644
--- a/arch/alpha/kernel/smp.c
+++ b/arch/alpha/kernel/smp.c
@@ -989,175 +989,3 @@
preempt_enable();
}
-
-#ifdef CONFIG_DEBUG_SPINLOCK
-void
-_raw_spin_unlock(spinlock_t * lock)
-{
- mb();
- lock->lock = 0;
-
- lock->on_cpu = -1;
- lock->previous = NULL;
- lock->task = NULL;
- lock->base_file = "none";
- lock->line_no = 0;
-}
-
-void
-debug_spin_lock(spinlock_t * lock, const char *base_file, int line_no)
-{
- long tmp;
- long stuck;
- void *inline_pc = __builtin_return_address(0);
- unsigned long started = jiffies;
- int printed = 0;
- int cpu = smp_processor_id();
-
- stuck = 1L << 30;
- try_again:
-
- /* Use sub-sections to put the actual loop at the end
- of this object file's text section so as to perfect
- branch prediction. */
- __asm__ __volatile__(
- "1: ldl_l %0,%1\n"
- " subq %2,1,%2\n"
- " blbs %0,2f\n"
- " or %0,1,%0\n"
- " stl_c %0,%1\n"
- " beq %0,3f\n"
- "4: mb\n"
- ".subsection 2\n"
- "2: ldl %0,%1\n"
- " subq %2,1,%2\n"
- "3: blt %2,4b\n"
- " blbs %0,2b\n"
- " br 1b\n"
- ".previous"
- : "=r" (tmp), "=m" (lock->lock), "=r" (stuck)
- : "m" (lock->lock), "2" (stuck) : "memory");
-
- if (stuck < 0) {
- printk(KERN_WARNING
- "%s:%d spinlock stuck in %s at %p(%d)"
- " owner %s at %p(%d) %s:%d\n",
- base_file, line_no,
- current->comm, inline_pc, cpu,
- lock->task->comm, lock->previous,
- lock->on_cpu, lock->base_file, lock->line_no);
- stuck = 1L << 36;
- printed = 1;
- goto try_again;
- }
-
- /* Exiting. Got the lock. */
- lock->on_cpu = cpu;
- lock->previous = inline_pc;
- lock->task = current;
- lock->base_file = base_file;
- lock->line_no = line_no;
-
- if (printed) {
- printk(KERN_WARNING
- "%s:%d spinlock grabbed in %s at %p(%d) %ld ticks\n",
- base_file, line_no, current->comm, inline_pc,
- cpu, jiffies - started);
- }
-}
-
-int
-debug_spin_trylock(spinlock_t * lock, const char *base_file, int line_no)
-{
- int ret;
- if ((ret = !test_and_set_bit(0, lock))) {
- lock->on_cpu = smp_processor_id();
- lock->previous = __builtin_return_address(0);
- lock->task = current;
- } else {
- lock->base_file = base_file;
- lock->line_no = line_no;
- }
- return ret;
-}
-#endif /* CONFIG_DEBUG_SPINLOCK */
-
-#ifdef CONFIG_DEBUG_RWLOCK
-void _raw_write_lock(rwlock_t * lock)
-{
- long regx, regy;
- int stuck_lock, stuck_reader;
- void *inline_pc = __builtin_return_address(0);
-
- try_again:
-
- stuck_lock = 1<<30;
- stuck_reader = 1<<30;
-
- __asm__ __volatile__(
- "1: ldl_l %1,%0\n"
- " blbs %1,6f\n"
- " blt %1,8f\n"
- " mov 1,%1\n"
- " stl_c %1,%0\n"
- " beq %1,6f\n"
- "4: mb\n"
- ".subsection 2\n"
- "6: blt %3,4b # debug\n"
- " subl %3,1,%3 # debug\n"
- " ldl %1,%0\n"
- " blbs %1,6b\n"
- "8: blt %4,4b # debug\n"
- " subl %4,1,%4 # debug\n"
- " ldl %1,%0\n"
- " blt %1,8b\n"
- " br 1b\n"
- ".previous"
- : "=m" (*(volatile int *)lock), "=&r" (regx), "=&r" (regy),
- "=&r" (stuck_lock), "=&r" (stuck_reader)
- : "m" (*(volatile int *)lock), "3" (stuck_lock), "4" (stuck_reader) : "memory");
-
- if (stuck_lock < 0) {
- printk(KERN_WARNING "write_lock stuck at %p\n", inline_pc);
- goto try_again;
- }
- if (stuck_reader < 0) {
- printk(KERN_WARNING "write_lock stuck on readers at %p\n",
- inline_pc);
- goto try_again;
- }
-}
-
-void _raw_read_lock(rwlock_t * lock)
-{
- long regx;
- int stuck_lock;
- void *inline_pc = __builtin_return_address(0);
-
- try_again:
-
- stuck_lock = 1<<30;
-
- __asm__ __volatile__(
- "1: ldl_l %1,%0;"
- " blbs %1,6f;"
- " subl %1,2,%1;"
- " stl_c %1,%0;"
- " beq %1,6f;"
- "4: mb\n"
- ".subsection 2\n"
- "6: ldl %1,%0;"
- " blt %2,4b # debug\n"
- " subl %2,1,%2 # debug\n"
- " blbs %1,6b;"
- " br 1b\n"
- ".previous"
- : "=m" (*(volatile int *)lock), "=&r" (regx), "=&r" (stuck_lock)
- : "m" (*(volatile int *)lock), "2" (stuck_lock) : "memory");
-
- if (stuck_lock < 0) {
- printk(KERN_WARNING "read_lock stuck at %p\n", inline_pc);
- goto try_again;
- }
-}
-#endif /* CONFIG_DEBUG_RWLOCK */
diff --git a/arch/ia64/kernel/mca.c b/arch/ia64/kernel/mca.c
index 4ebbf39..8d48420 100644
--- a/arch/ia64/kernel/mca.c
+++ b/arch/ia64/kernel/mca.c
@@ -491,12 +491,7 @@
unw_init_from_interruption(&info, current, pt, sw);
ia64_do_show_stack(&info, NULL);
-#ifdef CONFIG_SMP
- /* read_trylock() would be handy... */
- if (!tasklist_lock.write_lock)
- read_lock(&tasklist_lock);
-#endif
- {
+ if (read_trylock(&tasklist_lock)) {
struct task_struct *g, *t;
do_each_thread (g, t) {
if (t == current)
@@ -506,10 +501,6 @@
show_stack(t, NULL);
} while_each_thread (g, t);
}
-#ifdef CONFIG_SMP
- if (!tasklist_lock.write_lock)
- read_unlock(&tasklist_lock);
-#endif
printk("\nINIT dump complete. Please reboot now.\n");
while (1); /* hang city if no debugger */
diff --git a/arch/m32r/kernel/smp.c b/arch/m32r/kernel/smp.c
index 48b187f..a4576ac 100644
--- a/arch/m32r/kernel/smp.c
+++ b/arch/m32r/kernel/smp.c
@@ -892,7 +892,6 @@
int try)
{
spinlock_t *ipilock;
- unsigned long flags = 0;
volatile unsigned long *ipicr_addr;
unsigned long ipicr_val;
unsigned long my_physid_mask;
@@ -916,50 +915,27 @@
* write IPICRi (send IPIi)
* unlock ipi_lock[i]
*/
+ spin_lock(ipilock);
__asm__ __volatile__ (
- ";; LOCK ipi_lock[i] \n\t"
- ".fillinsn \n"
- "1: \n\t"
- "mvfc %1, psw \n\t"
- "clrpsw #0x40 -> nop \n\t"
- DCACHE_CLEAR("r4", "r5", "%2")
- "lock r4, @%2 \n\t"
- "addi r4, #-1 \n\t"
- "unlock r4, @%2 \n\t"
- "mvtc %1, psw \n\t"
- "bnez r4, 2f \n\t"
- LOCK_SECTION_START(".balign 4 \n\t")
- ".fillinsn \n"
- "2: \n\t"
- "ld r4, @%2 \n\t"
- "blez r4, 2b \n\t"
- "bra 1b \n\t"
- LOCK_SECTION_END
";; CHECK IPICRi == 0 \n\t"
".fillinsn \n"
- "3: \n\t"
- "ld %0, @%3 \n\t"
- "and %0, %6 \n\t"
- "beqz %0, 4f \n\t"
- "bnez %5, 5f \n\t"
- "bra 3b \n\t"
+ "1: \n\t"
+ "ld %0, @%1 \n\t"
+ "and %0, %4 \n\t"
+ "beqz %0, 2f \n\t"
+ "bnez %3, 3f \n\t"
+ "bra 1b \n\t"
";; WRITE IPICRi (send IPIi) \n\t"
".fillinsn \n"
- "4: \n\t"
- "st %4, @%3 \n\t"
- ";; UNLOCK ipi_lock[i] \n\t"
+ "2: \n\t"
+ "st %2, @%1 \n\t"
".fillinsn \n"
- "5: \n\t"
- "ldi r4, #1 \n\t"
- "st r4, @%2 \n\t"
+ "3: \n\t"
: "=&r"(ipicr_val)
- : "r"(flags), "r"(&ipilock->slock), "r"(ipicr_addr),
- "r"(mask), "r"(try), "r"(my_physid_mask)
- : "memory", "r4"
-#ifdef CONFIG_CHIP_M32700_TS1
- , "r5"
-#endif /* CONFIG_CHIP_M32700_TS1 */
+ : "r"(ipicr_addr), "r"(mask), "r"(try), "r"(my_physid_mask)
+ : "memory"
);
+ spin_unlock(ipilock);
return ipicr_val;
}
diff --git a/arch/mips/lib/dec_and_lock.c b/arch/mips/lib/dec_and_lock.c
index e44e957..fd82c84 100644
--- a/arch/mips/lib/dec_and_lock.c
+++ b/arch/mips/lib/dec_and_lock.c
@@ -20,14 +20,7 @@
* has a cmpxchg, and where atomic->value is an int holding
* the value of the atomic (i.e. the high bits aren't used
* for a lock or anything like that).
- *
- * N.B. ATOMIC_DEC_AND_LOCK gets defined in include/linux/spinlock.h
- * if spinlocks are empty and thus atomic_dec_and_lock is defined
- * to be atomic_dec_and_test - in that case we don't need it
- * defined here as well.
*/
-
-#ifndef ATOMIC_DEC_AND_LOCK
int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
{
int counter;
@@ -52,4 +45,3 @@
}
EXPORT_SYMBOL(_atomic_dec_and_lock);
-#endif /* ATOMIC_DEC_AND_LOCK */
diff --git a/arch/parisc/lib/Makefile b/arch/parisc/lib/Makefile
index 7bf7056..5f2e690 100644
--- a/arch/parisc/lib/Makefile
+++ b/arch/parisc/lib/Makefile
@@ -5,5 +5,3 @@
lib-y := lusercopy.o bitops.o checksum.o io.o memset.o fixup.o memcpy.o
obj-y := iomap.o
-
-lib-$(CONFIG_SMP) += debuglocks.o
diff --git a/arch/parisc/lib/bitops.c b/arch/parisc/lib/bitops.c
index 2de182f..90f400b 100644
--- a/arch/parisc/lib/bitops.c
+++ b/arch/parisc/lib/bitops.c
@@ -13,8 +13,8 @@
#include <asm/atomic.h>
#ifdef CONFIG_SMP
-spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
- [0 ... (ATOMIC_HASH_SIZE-1)] = SPIN_LOCK_UNLOCKED
+raw_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
+ [0 ... (ATOMIC_HASH_SIZE-1)] = __RAW_SPIN_LOCK_UNLOCKED
};
#endif
diff --git a/arch/parisc/lib/debuglocks.c b/arch/parisc/lib/debuglocks.c
deleted file mode 100644
index 1b33fe6..0000000
--- a/arch/parisc/lib/debuglocks.c
+++ /dev/null
@@ -1,277 +0,0 @@
-/*
- * Debugging versions of SMP locking primitives.
- *
- * Copyright (C) 2004 Thibaut VARENE <varenet@parisc-linux.org>
- *
- * Some code stollen from alpha & sparc64 ;)
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
- * We use pdc_printf() throughout the file for all output messages, to avoid
- * losing messages because of disabled interrupts. Since we're using these
- * messages for debugging purposes, it makes sense not to send them to the
- * linux console.
- */
-
-
-#include <linux/config.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/spinlock.h>
-#include <linux/hardirq.h> /* in_interrupt() */
-#include <asm/system.h>
-#include <asm/hardirq.h> /* in_interrupt() */
-#include <asm/pdc.h>
-
-#undef INIT_STUCK
-#define INIT_STUCK 1L << 30
-
-#ifdef CONFIG_DEBUG_SPINLOCK
-
-
-void _dbg_spin_lock(spinlock_t * lock, const char *base_file, int line_no)
-{
- volatile unsigned int *a;
- long stuck = INIT_STUCK;
- void *inline_pc = __builtin_return_address(0);
- unsigned long started = jiffies;
- int printed = 0;
- int cpu = smp_processor_id();
-
-try_again:
-
- /* Do the actual locking */
- /* <T-Bone> ggg: we can't get stuck on the outter loop?
- * <ggg> T-Bone: We can hit the outer loop
- * alot if multiple CPUs are constantly racing for a lock
- * and the backplane is NOT fair about which CPU sees
- * the update first. But it won't hang since every failed
- * attempt will drop us back into the inner loop and
- * decrement `stuck'.
- * <ggg> K-class and some of the others are NOT fair in the HW
- * implementation so we could see false positives.
- * But fixing the lock contention is easier than
- * fixing the HW to be fair.
- * <tausq> __ldcw() returns 1 if we get the lock; otherwise we
- * spin until the value of the lock changes, or we time out.
- */
- mb();
- a = __ldcw_align(lock);
- while (stuck && (__ldcw(a) == 0))
- while ((*a == 0) && --stuck);
- mb();
-
- if (unlikely(stuck <= 0)) {
- pdc_printf(
- "%s:%d: spin_lock(%s/%p) stuck in %s at %p(%d)"
- " owned by %s:%d in %s at %p(%d)\n",
- base_file, line_no, lock->module, lock,
- current->comm, inline_pc, cpu,
- lock->bfile, lock->bline, lock->task->comm,
- lock->previous, lock->oncpu);
- stuck = INIT_STUCK;
- printed = 1;
- goto try_again;
- }
-
- /* Exiting. Got the lock. */
- lock->oncpu = cpu;
- lock->previous = inline_pc;
- lock->task = current;
- lock->bfile = (char *)base_file;
- lock->bline = line_no;
-
- if (unlikely(printed)) {
- pdc_printf(
- "%s:%d: spin_lock grabbed in %s at %p(%d) %ld ticks\n",
- base_file, line_no, current->comm, inline_pc,
- cpu, jiffies - started);
- }
-}
-
-void _dbg_spin_unlock(spinlock_t * lock, const char *base_file, int line_no)
-{
- CHECK_LOCK(lock);
- volatile unsigned int *a;
- mb();
- a = __ldcw_align(lock);
- if (unlikely((*a != 0) && lock->babble)) {
- lock->babble--;
- pdc_printf(
- "%s:%d: spin_unlock(%s:%p) not locked\n",
- base_file, line_no, lock->module, lock);
- }
- *a = 1;
- mb();
-}
-
-int _dbg_spin_trylock(spinlock_t * lock, const char *base_file, int line_no)
-{
- int ret;
- volatile unsigned int *a;
- mb();
- a = __ldcw_align(lock);
- ret = (__ldcw(a) != 0);
- mb();
- if (ret) {
- lock->oncpu = smp_processor_id();
- lock->previous = __builtin_return_address(0);
- lock->task = current;
- } else {
- lock->bfile = (char *)base_file;
- lock->bline = line_no;
- }
- return ret;
-}
-
-#endif /* CONFIG_DEBUG_SPINLOCK */
-
-#ifdef CONFIG_DEBUG_RWLOCK
-
-/* Interrupts trouble detailed explanation, thx Grant:
- *
- * o writer (wants to modify data) attempts to acquire the rwlock
- * o He gets the write lock.
- * o Interupts are still enabled, we take an interrupt with the
- * write still holding the lock.
- * o interrupt handler tries to acquire the rwlock for read.
- * o deadlock since the writer can't release it at this point.
- *
- * In general, any use of spinlocks that competes between "base"
- * level and interrupt level code will risk deadlock. Interrupts
- * need to be disabled in the base level routines to avoid it.
- * Or more precisely, only the IRQ the base level routine
- * is competing with for the lock. But it's more efficient/faster
- * to just disable all interrupts on that CPU to guarantee
- * once it gets the lock it can release it quickly too.
- */
-
-void _dbg_write_lock(rwlock_t *rw, const char *bfile, int bline)
-{
- void *inline_pc = __builtin_return_address(0);
- unsigned long started = jiffies;
- long stuck = INIT_STUCK;
- int printed = 0;
- int cpu = smp_processor_id();
-
- if(unlikely(in_interrupt())) { /* acquiring write lock in interrupt context, bad idea */
- pdc_printf("write_lock caller: %s:%d, IRQs enabled,\n", bfile, bline);
- BUG();
- }
-
- /* Note: if interrupts are disabled (which is most likely), the printk
- will never show on the console. We might need a polling method to flush
- the dmesg buffer anyhow. */
-
-retry:
- _raw_spin_lock(&rw->lock);
-
- if(rw->counter != 0) {
- /* this basically never happens */
- _raw_spin_unlock(&rw->lock);
-
- stuck--;
- if ((unlikely(stuck <= 0)) && (rw->counter < 0)) {
- pdc_printf(
- "%s:%d: write_lock stuck on writer"
- " in %s at %p(%d) %ld ticks\n",
- bfile, bline, current->comm, inline_pc,
- cpu, jiffies - started);
- stuck = INIT_STUCK;
- printed = 1;
- }
- else if (unlikely(stuck <= 0)) {
- pdc_printf(
- "%s:%d: write_lock stuck on reader"
- " in %s at %p(%d) %ld ticks\n",
- bfile, bline, current->comm, inline_pc,
- cpu, jiffies - started);
- stuck = INIT_STUCK;
- printed = 1;
- }
-
- while(rw->counter != 0);
-
- goto retry;
- }
-
- /* got it. now leave without unlocking */
- rw->counter = -1; /* remember we are locked */
-
- if (unlikely(printed)) {
- pdc_printf(
- "%s:%d: write_lock grabbed in %s at %p(%d) %ld ticks\n",
- bfile, bline, current->comm, inline_pc,
- cpu, jiffies - started);
- }
-}
-
-int _dbg_write_trylock(rwlock_t *rw, const char *bfile, int bline)
-{
-#if 0
- void *inline_pc = __builtin_return_address(0);
- int cpu = smp_processor_id();
-#endif
-
- if(unlikely(in_interrupt())) { /* acquiring write lock in interrupt context, bad idea */
- pdc_printf("write_lock caller: %s:%d, IRQs enabled,\n", bfile, bline);
- BUG();
- }
-
- /* Note: if interrupts are disabled (which is most likely), the printk
- will never show on the console. We might need a polling method to flush
- the dmesg buffer anyhow. */
-
- _raw_spin_lock(&rw->lock);
-
- if(rw->counter != 0) {
- /* this basically never happens */
- _raw_spin_unlock(&rw->lock);
- return 0;
- }
-
- /* got it. now leave without unlocking */
- rw->counter = -1; /* remember we are locked */
-#if 0
- pdc_printf("%s:%d: try write_lock grabbed in %s at %p(%d)\n",
- bfile, bline, current->comm, inline_pc, cpu);
-#endif
- return 1;
-}
-
-void _dbg_read_lock(rwlock_t * rw, const char *bfile, int bline)
-{
-#if 0
- void *inline_pc = __builtin_return_address(0);
- unsigned long started = jiffies;
- int cpu = smp_processor_id();
-#endif
- unsigned long flags;
-
- local_irq_save(flags);
- _raw_spin_lock(&rw->lock);
-
- rw->counter++;
-#if 0
- pdc_printf(
- "%s:%d: read_lock grabbed in %s at %p(%d) %ld ticks\n",
- bfile, bline, current->comm, inline_pc,
- cpu, jiffies - started);
-#endif
- _raw_spin_unlock(&rw->lock);
- local_irq_restore(flags);
-}
-
-#endif /* CONFIG_DEBUG_RWLOCK */
diff --git a/arch/ppc/lib/Makefile b/arch/ppc/lib/Makefile
index 1c380e6..f1e1fb4 100644
--- a/arch/ppc/lib/Makefile
+++ b/arch/ppc/lib/Makefile
@@ -4,6 +4,5 @@
obj-y := checksum.o string.o strcase.o dec_and_lock.o div64.o
-obj-$(CONFIG_SMP) += locks.o
obj-$(CONFIG_8xx) += rheap.o
obj-$(CONFIG_CPM2) += rheap.o
diff --git a/arch/ppc/lib/dec_and_lock.c b/arch/ppc/lib/dec_and_lock.c
index 4ee8880..b18f0d9 100644
--- a/arch/ppc/lib/dec_and_lock.c
+++ b/arch/ppc/lib/dec_and_lock.c
@@ -11,14 +11,7 @@
* has a cmpxchg, and where atomic->value is an int holding
* the value of the atomic (i.e. the high bits aren't used
* for a lock or anything like that).
- *
- * N.B. ATOMIC_DEC_AND_LOCK gets defined in include/linux/spinlock.h
- * if spinlocks are empty and thus atomic_dec_and_lock is defined
- * to be atomic_dec_and_test - in that case we don't need it
- * defined here as well.
*/
-
-#ifndef ATOMIC_DEC_AND_LOCK
int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
{
int counter;
@@ -43,4 +36,3 @@
}
EXPORT_SYMBOL(_atomic_dec_and_lock);
-#endif /* ATOMIC_DEC_AND_LOCK */
diff --git a/arch/ppc64/lib/dec_and_lock.c b/arch/ppc64/lib/dec_and_lock.c
index 6e8d859..7b9d4da 100644
--- a/arch/ppc64/lib/dec_and_lock.c
+++ b/arch/ppc64/lib/dec_and_lock.c
@@ -20,14 +20,7 @@
* has a cmpxchg, and where atomic->value is an int holding
* the value of the atomic (i.e. the high bits aren't used
* for a lock or anything like that).
- *
- * N.B. ATOMIC_DEC_AND_LOCK gets defined in include/linux/spinlock.h
- * if spinlocks are empty and thus atomic_dec_and_lock is defined
- * to be atomic_dec_and_test - in that case we don't need it
- * defined here as well.
*/
-
-#ifndef ATOMIC_DEC_AND_LOCK
int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock)
{
int counter;
@@ -52,4 +45,3 @@
}
EXPORT_SYMBOL(_atomic_dec_and_lock);
-#endif /* ATOMIC_DEC_AND_LOCK */
diff --git a/arch/ppc64/lib/locks.c b/arch/ppc64/lib/locks.c
index ef70ef9..033643a 100644
--- a/arch/ppc64/lib/locks.c
+++ b/arch/ppc64/lib/locks.c
@@ -23,12 +23,12 @@
/* waiting for a spinlock... */
#if defined(CONFIG_PPC_SPLPAR) || defined(CONFIG_PPC_ISERIES)
-void __spin_yield(spinlock_t *lock)
+void __spin_yield(raw_spinlock_t *lock)
{
unsigned int lock_value, holder_cpu, yield_count;
struct paca_struct *holder_paca;
- lock_value = lock->lock;
+ lock_value = lock->slock;
if (lock_value == 0)
return;
holder_cpu = lock_value & 0xffff;
@@ -38,7 +38,7 @@
if ((yield_count & 1) == 0)
return; /* virtual cpu is currently running */
rmb();
- if (lock->lock != lock_value)
+ if (lock->slock != lock_value)
return; /* something has changed */
#ifdef CONFIG_PPC_ISERIES
HvCall2(HvCallBaseYieldProcessor, HvCall_YieldToProc,
@@ -54,7 +54,7 @@
* This turns out to be the same for read and write locks, since
* we only know the holder if it is write-locked.
*/
-void __rw_yield(rwlock_t *rw)
+void __rw_yield(raw_rwlock_t *rw)
{
int lock_value;
unsigned int holder_cpu, yield_count;
@@ -82,9 +82,9 @@
}
#endif
-void spin_unlock_wait(spinlock_t *lock)
+void __raw_spin_unlock_wait(raw_spinlock_t *lock)
{
- while (lock->lock) {
+ while (lock->slock) {
HMT_low();
if (SHARED_PROCESSOR)
__spin_yield(lock);
@@ -92,4 +92,4 @@
HMT_medium();
}
-EXPORT_SYMBOL(spin_unlock_wait);
+EXPORT_SYMBOL(__raw_spin_unlock_wait);
diff --git a/arch/s390/lib/spinlock.c b/arch/s390/lib/spinlock.c
index 888b559..2dc14e9 100644
--- a/arch/s390/lib/spinlock.c
+++ b/arch/s390/lib/spinlock.c
@@ -36,7 +36,7 @@
}
void
-_raw_spin_lock_wait(spinlock_t *lp, unsigned int pc)
+_raw_spin_lock_wait(raw_spinlock_t *lp, unsigned int pc)
{
int count = spin_retry;
@@ -53,7 +53,7 @@
EXPORT_SYMBOL(_raw_spin_lock_wait);
int
-_raw_spin_trylock_retry(spinlock_t *lp, unsigned int pc)
+_raw_spin_trylock_retry(raw_spinlock_t *lp, unsigned int pc)
{
int count = spin_retry;
@@ -67,7 +67,7 @@
EXPORT_SYMBOL(_raw_spin_trylock_retry);
void
-_raw_read_lock_wait(rwlock_t *rw)
+_raw_read_lock_wait(raw_rwlock_t *rw)
{
unsigned int old;
int count = spin_retry;
@@ -86,7 +86,7 @@
EXPORT_SYMBOL(_raw_read_lock_wait);
int
-_raw_read_trylock_retry(rwlock_t *rw)
+_raw_read_trylock_retry(raw_rwlock_t *rw)
{
unsigned int old;
int count = spin_retry;
@@ -102,7 +102,7 @@
EXPORT_SYMBOL(_raw_read_trylock_retry);
void
-_raw_write_lock_wait(rwlock_t *rw)
+_raw_write_lock_wait(raw_rwlock_t *rw)
{
int count = spin_retry;
@@ -119,7 +119,7 @@
EXPORT_SYMBOL(_raw_write_lock_wait);
int
-_raw_write_trylock_retry(rwlock_t *rw)
+_raw_write_trylock_retry(raw_rwlock_t *rw)
{
int count = spin_retry;
diff --git a/arch/sparc/kernel/sparc_ksyms.c b/arch/sparc/kernel/sparc_ksyms.c
index 5d974a2..f848093 100644
--- a/arch/sparc/kernel/sparc_ksyms.c
+++ b/arch/sparc/kernel/sparc_ksyms.c
@@ -114,17 +114,7 @@
/* used by various drivers */
EXPORT_SYMBOL(sparc_cpu_model);
EXPORT_SYMBOL(kernel_thread);
-#ifdef CONFIG_DEBUG_SPINLOCK
#ifdef CONFIG_SMP
-EXPORT_SYMBOL(_do_spin_lock);
-EXPORT_SYMBOL(_do_spin_unlock);
-EXPORT_SYMBOL(_spin_trylock);
-EXPORT_SYMBOL(_do_read_lock);
-EXPORT_SYMBOL(_do_read_unlock);
-EXPORT_SYMBOL(_do_write_lock);
-EXPORT_SYMBOL(_do_write_unlock);
-#endif
-#else
// XXX find what uses (or used) these.
EXPORT_SYMBOL(___rw_read_enter);
EXPORT_SYMBOL(___rw_read_exit);
diff --git a/arch/sparc/lib/Makefile b/arch/sparc/lib/Makefile
index 2296ff9..fa50069 100644
--- a/arch/sparc/lib/Makefile
+++ b/arch/sparc/lib/Makefile
@@ -9,5 +9,3 @@
strncpy_from_user.o divdi3.o udivdi3.o strlen_user.o \
copy_user.o locks.o atomic.o atomic32.o bitops.o \
lshrdi3.o ashldi3.o rwsem.o muldi3.o bitext.o
-
-lib-$(CONFIG_DEBUG_SPINLOCK) += debuglocks.o
diff --git a/arch/sparc/lib/debuglocks.c b/arch/sparc/lib/debuglocks.c
deleted file mode 100644
index fb18235..0000000
--- a/arch/sparc/lib/debuglocks.c
+++ /dev/null
@@ -1,202 +0,0 @@
-/* $Id: debuglocks.c,v 1.11 2001/09/20 00:35:31 davem Exp $
- * debuglocks.c: Debugging versions of SMP locking primitives.
- *
- * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
- * Copyright (C) 1998-99 Anton Blanchard (anton@progsoc.uts.edu.au)
- */
-
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/threads.h> /* For NR_CPUS */
-#include <linux/spinlock.h>
-#include <asm/psr.h>
-#include <asm/system.h>
-
-#ifdef CONFIG_SMP
-
-/* Some notes on how these debugging routines work. When a lock is acquired
- * an extra debugging member lock->owner_pc is set to the caller of the lock
- * acquisition routine. Right before releasing a lock, the debugging program
- * counter is cleared to zero.
- *
- * Furthermore, since PC's are 4 byte aligned on Sparc, we stuff the CPU
- * number of the owner in the lowest two bits.
- */
-
-#define STORE_CALLER(A) __asm__ __volatile__("mov %%i7, %0" : "=r" (A));
-
-static inline void show(char *str, spinlock_t *lock, unsigned long caller)
-{
- int cpu = smp_processor_id();
-
- printk("%s(%p) CPU#%d stuck at %08lx, owner PC(%08lx):CPU(%lx)\n",str,
- lock, cpu, caller, lock->owner_pc & ~3, lock->owner_pc & 3);
-}
-
-static inline void show_read(char *str, rwlock_t *lock, unsigned long caller)
-{
- int cpu = smp_processor_id();
-
- printk("%s(%p) CPU#%d stuck at %08lx, owner PC(%08lx):CPU(%lx)\n", str,
- lock, cpu, caller, lock->owner_pc & ~3, lock->owner_pc & 3);
-}
-
-static inline void show_write(char *str, rwlock_t *lock, unsigned long caller)
-{
- int cpu = smp_processor_id();
- int i;
-
- printk("%s(%p) CPU#%d stuck at %08lx, owner PC(%08lx):CPU(%lx)", str,
- lock, cpu, caller, lock->owner_pc & ~3, lock->owner_pc & 3);
-
- for(i = 0; i < NR_CPUS; i++)
- printk(" reader[%d]=%08lx", i, lock->reader_pc[i]);
-
- printk("\n");
-}
-
-#undef INIT_STUCK
-#define INIT_STUCK 100000000
-
-void _do_spin_lock(spinlock_t *lock, char *str)
-{
- unsigned long caller;
- unsigned long val;
- int cpu = smp_processor_id();
- int stuck = INIT_STUCK;
-
- STORE_CALLER(caller);
-
-again:
- __asm__ __volatile__("ldstub [%1], %0" : "=r" (val) : "r" (&(lock->lock)));
- if(val) {
- while(lock->lock) {
- if (!--stuck) {
- show(str, lock, caller);
- stuck = INIT_STUCK;
- }
- barrier();
- }
- goto again;
- }
- lock->owner_pc = (cpu & 3) | (caller & ~3);
-}
-
-int _spin_trylock(spinlock_t *lock)
-{
- unsigned long val;
- unsigned long caller;
- int cpu = smp_processor_id();
-
- STORE_CALLER(caller);
-
- __asm__ __volatile__("ldstub [%1], %0" : "=r" (val) : "r" (&(lock->lock)));
- if(!val) {
- /* We got it, record our identity for debugging. */
- lock->owner_pc = (cpu & 3) | (caller & ~3);
- }
- return val == 0;
-}
-
-void _do_spin_unlock(spinlock_t *lock)
-{
- lock->owner_pc = 0;
- barrier();
- lock->lock = 0;
-}
-
-void _do_read_lock(rwlock_t *rw, char *str)
-{
- unsigned long caller;
- unsigned long val;
- int cpu = smp_processor_id();
- int stuck = INIT_STUCK;
-
- STORE_CALLER(caller);
-
-wlock_again:
- __asm__ __volatile__("ldstub [%1 + 3], %0" : "=r" (val) : "r" (&(rw->lock)));
- if(val) {
- while(rw->lock & 0xff) {
- if (!--stuck) {
- show_read(str, rw, caller);
- stuck = INIT_STUCK;
- }
- barrier();
- }
- goto wlock_again;
- }
-
- rw->reader_pc[cpu] = caller;
- barrier();
- rw->lock++;
-}
-
-void _do_read_unlock(rwlock_t *rw, char *str)
-{
- unsigned long caller;
- unsigned long val;
- int cpu = smp_processor_id();
- int stuck = INIT_STUCK;
-
- STORE_CALLER(caller);
-
-wlock_again:
- __asm__ __volatile__("ldstub [%1 + 3], %0" : "=r" (val) : "r" (&(rw->lock)));
- if(val) {
- while(rw->lock & 0xff) {
- if (!--stuck) {
- show_read(str, rw, caller);
- stuck = INIT_STUCK;
- }
- barrier();
- }
- goto wlock_again;
- }
-
- rw->reader_pc[cpu] = 0;
- barrier();
- rw->lock -= 0x1ff;
-}
-
-void _do_write_lock(rwlock_t *rw, char *str)
-{
- unsigned long caller;
- unsigned long val;
- int cpu = smp_processor_id();
- int stuck = INIT_STUCK;
-
- STORE_CALLER(caller);
-
-wlock_again:
- __asm__ __volatile__("ldstub [%1 + 3], %0" : "=r" (val) : "r" (&(rw->lock)));
- if(val) {
-wlock_wait:
- while(rw->lock) {
- if (!--stuck) {
- show_write(str, rw, caller);
- stuck = INIT_STUCK;
- }
- barrier();
- }
- goto wlock_again;
- }
-
- if (rw->lock & ~0xff) {
- *(((unsigned char *)&rw->lock)+3) = 0;
- barrier();
- goto wlock_wait;
- }
-
- barrier();
- rw->owner_pc = (cpu & 3) | (caller & ~3);
-}
-
-void _do_write_unlock(rwlock_t *rw)
-{
- rw->owner_pc = 0;
- barrier();
- rw->lock = 0;
-}
-
-#endif /* SMP */
diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c
index 6625543..7d10b03 100644
--- a/arch/sparc64/kernel/process.c
+++ b/arch/sparc64/kernel/process.c
@@ -607,11 +607,6 @@
struct thread_info *t = p->thread_info;
char *child_trap_frame;
-#ifdef CONFIG_DEBUG_SPINLOCK
- p->thread.smp_lock_count = 0;
- p->thread.smp_lock_pc = 0;
-#endif
-
/* Calculate offset to stack_frame & pt_regs */
child_trap_frame = ((char *)t) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
diff --git a/arch/sparc64/kernel/sparc64_ksyms.c b/arch/sparc64/kernel/sparc64_ksyms.c
index 7d9a0f6..cbb5e59 100644
--- a/arch/sparc64/kernel/sparc64_ksyms.c
+++ b/arch/sparc64/kernel/sparc64_ksyms.c
@@ -115,17 +115,12 @@
/* used by various drivers */
#ifdef CONFIG_SMP
-#ifndef CONFIG_DEBUG_SPINLOCK
/* Out of line rw-locking implementation. */
EXPORT_SYMBOL(__read_lock);
EXPORT_SYMBOL(__read_unlock);
EXPORT_SYMBOL(__write_lock);
EXPORT_SYMBOL(__write_unlock);
EXPORT_SYMBOL(__write_trylock);
-/* Out of line spin-locking implementation. */
-EXPORT_SYMBOL(_raw_spin_lock);
-EXPORT_SYMBOL(_raw_spin_lock_flags);
-#endif
/* Hard IRQ locking */
EXPORT_SYMBOL(synchronize_irq);
diff --git a/arch/sparc64/lib/Makefile b/arch/sparc64/lib/Makefile
index 40dbeec..d968aeb 100644
--- a/arch/sparc64/lib/Makefile
+++ b/arch/sparc64/lib/Makefile
@@ -14,7 +14,6 @@
copy_in_user.o user_fixup.o memmove.o \
mcount.o ipcsum.o rwsem.o xor.o find_bit.o delay.o
-lib-$(CONFIG_DEBUG_SPINLOCK) += debuglocks.o
lib-$(CONFIG_HAVE_DEC_LOCK) += dec_and_lock.o
obj-y += iomap.o
diff --git a/arch/sparc64/lib/debuglocks.c b/arch/sparc64/lib/debuglocks.c
deleted file mode 100644
index f5f0b55..0000000
--- a/arch/sparc64/lib/debuglocks.c
+++ /dev/null
@@ -1,366 +0,0 @@
-/* $Id: debuglocks.c,v 1.9 2001/11/17 00:10:48 davem Exp $
- * debuglocks.c: Debugging versions of SMP locking primitives.
- *
- * Copyright (C) 1998 David S. Miller (davem@redhat.com)
- */
-
-#include <linux/config.h>
-#include <linux/kernel.h>
-#include <linux/sched.h>
-#include <linux/spinlock.h>
-#include <asm/system.h>
-
-#ifdef CONFIG_SMP
-
-static inline void show (char *str, spinlock_t *lock, unsigned long caller)
-{
- int cpu = smp_processor_id();
-
- printk("%s(%p) CPU#%d stuck at %08x, owner PC(%08x):CPU(%x)\n",
- str, lock, cpu, (unsigned int) caller,
- lock->owner_pc, lock->owner_cpu);
-}
-
-static inline void show_read (char *str, rwlock_t *lock, unsigned long caller)
-{
- int cpu = smp_processor_id();
-
- printk("%s(%p) CPU#%d stuck at %08x, writer PC(%08x):CPU(%x)\n",
- str, lock, cpu, (unsigned int) caller,
- lock->writer_pc, lock->writer_cpu);
-}
-
-static inline void show_write (char *str, rwlock_t *lock, unsigned long caller)
-{
- int cpu = smp_processor_id();
- int i;
-
- printk("%s(%p) CPU#%d stuck at %08x\n",
- str, lock, cpu, (unsigned int) caller);
- printk("Writer: PC(%08x):CPU(%x)\n",
- lock->writer_pc, lock->writer_cpu);
- printk("Readers:");
- for (i = 0; i < NR_CPUS; i++)
- if (lock->reader_pc[i])
- printk(" %d[%08x]", i, lock->reader_pc[i]);
- printk("\n");
-}
-
-#undef INIT_STUCK
-#define INIT_STUCK 100000000
-
-void _do_spin_lock(spinlock_t *lock, char *str, unsigned long caller)
-{
- unsigned long val;
- int stuck = INIT_STUCK;
- int cpu = get_cpu();
- int shown = 0;
-
-again:
- __asm__ __volatile__("ldstub [%1], %0"
- : "=r" (val)
- : "r" (&(lock->lock))
- : "memory");
- membar_storeload_storestore();
- if (val) {
- while (lock->lock) {
- if (!--stuck) {
- if (shown++ <= 2)
- show(str, lock, caller);
- stuck = INIT_STUCK;
- }
- rmb();
- }
- goto again;
- }
- lock->owner_pc = ((unsigned int)caller);
- lock->owner_cpu = cpu;
- current->thread.smp_lock_count++;
- current->thread.smp_lock_pc = ((unsigned int)caller);
-
- put_cpu();
-}
-
-int _do_spin_trylock(spinlock_t *lock, unsigned long caller)
-{
- unsigned long val;
- int cpu = get_cpu();
-
- __asm__ __volatile__("ldstub [%1], %0"
- : "=r" (val)
- : "r" (&(lock->lock))
- : "memory");
- membar_storeload_storestore();
- if (!val) {
- lock->owner_pc = ((unsigned int)caller);
- lock->owner_cpu = cpu;
- current->thread.smp_lock_count++;
- current->thread.smp_lock_pc = ((unsigned int)caller);
- }
-
- put_cpu();
-
- return val == 0;
-}
-
-void _do_spin_unlock(spinlock_t *lock)
-{
- lock->owner_pc = 0;
- lock->owner_cpu = NO_PROC_ID;
- membar_storestore_loadstore();
- lock->lock = 0;
- current->thread.smp_lock_count--;
-}
-
-/* Keep INIT_STUCK the same... */
-
-void _do_read_lock(rwlock_t *rw, char *str, unsigned long caller)
-{
- unsigned long val;
- int stuck = INIT_STUCK;
- int cpu = get_cpu();
- int shown = 0;
-
-wlock_again:
- /* Wait for any writer to go away. */
- while (((long)(rw->lock)) < 0) {
- if (!--stuck) {
- if (shown++ <= 2)
- show_read(str, rw, caller);
- stuck = INIT_STUCK;
- }
- rmb();
- }
- /* Try once to increment the counter. */
- __asm__ __volatile__(
-" ldx [%0], %%g1\n"
-" brlz,a,pn %%g1, 2f\n"
-" mov 1, %0\n"
-" add %%g1, 1, %%g7\n"
-" casx [%0], %%g1, %%g7\n"
-" sub %%g1, %%g7, %0\n"
-"2:" : "=r" (val)
- : "0" (&(rw->lock))
- : "g1", "g7", "memory");
- membar_storeload_storestore();
- if (val)
- goto wlock_again;
- rw->reader_pc[cpu] = ((unsigned int)caller);
- current->thread.smp_lock_count++;
- current->thread.smp_lock_pc = ((unsigned int)caller);
-
- put_cpu();
-}
-
-void _do_read_unlock(rwlock_t *rw, char *str, unsigned long caller)
-{
- unsigned long val;
- int stuck = INIT_STUCK;
- int cpu = get_cpu();
- int shown = 0;
-
- /* Drop our identity _first_. */
- rw->reader_pc[cpu] = 0;
- current->thread.smp_lock_count--;
-runlock_again:
- /* Spin trying to decrement the counter using casx. */
- __asm__ __volatile__(
-" membar #StoreLoad | #LoadLoad\n"
-" ldx [%0], %%g1\n"
-" sub %%g1, 1, %%g7\n"
-" casx [%0], %%g1, %%g7\n"
-" membar #StoreLoad | #StoreStore\n"
-" sub %%g1, %%g7, %0\n"
- : "=r" (val)
- : "0" (&(rw->lock))
- : "g1", "g7", "memory");
- if (val) {
- if (!--stuck) {
- if (shown++ <= 2)
- show_read(str, rw, caller);
- stuck = INIT_STUCK;
- }
- goto runlock_again;
- }
-
- put_cpu();
-}
-
-void _do_write_lock(rwlock_t *rw, char *str, unsigned long caller)
-{
- unsigned long val;
- int stuck = INIT_STUCK;
- int cpu = get_cpu();
- int shown = 0;
-
-wlock_again:
- /* Spin while there is another writer. */
- while (((long)rw->lock) < 0) {
- if (!--stuck) {
- if (shown++ <= 2)
- show_write(str, rw, caller);
- stuck = INIT_STUCK;
- }
- rmb();
- }
-
- /* Try to acuire the write bit. */
- __asm__ __volatile__(
-" mov 1, %%g3\n"
-" sllx %%g3, 63, %%g3\n"
-" ldx [%0], %%g1\n"
-" brlz,pn %%g1, 1f\n"
-" or %%g1, %%g3, %%g7\n"
-" casx [%0], %%g1, %%g7\n"
-" membar #StoreLoad | #StoreStore\n"
-" ba,pt %%xcc, 2f\n"
-" sub %%g1, %%g7, %0\n"
-"1: mov 1, %0\n"
-"2:" : "=r" (val)
- : "0" (&(rw->lock))
- : "g3", "g1", "g7", "memory");
- if (val) {
- /* We couldn't get the write bit. */
- if (!--stuck) {
- if (shown++ <= 2)
- show_write(str, rw, caller);
- stuck = INIT_STUCK;
- }
- goto wlock_again;
- }
- if ((rw->lock & ((1UL<<63)-1UL)) != 0UL) {
- /* Readers still around, drop the write
- * lock, spin, and try again.
- */
- if (!--stuck) {
- if (shown++ <= 2)
- show_write(str, rw, caller);
- stuck = INIT_STUCK;
- }
- __asm__ __volatile__(
-" mov 1, %%g3\n"
-" sllx %%g3, 63, %%g3\n"
-"1: ldx [%0], %%g1\n"
-" andn %%g1, %%g3, %%g7\n"
-" casx [%0], %%g1, %%g7\n"
-" cmp %%g1, %%g7\n"
-" membar #StoreLoad | #StoreStore\n"
-" bne,pn %%xcc, 1b\n"
-" nop"
- : /* no outputs */
- : "r" (&(rw->lock))
- : "g3", "g1", "g7", "cc", "memory");
- while(rw->lock != 0) {
- if (!--stuck) {
- if (shown++ <= 2)
- show_write(str, rw, caller);
- stuck = INIT_STUCK;
- }
- rmb();
- }
- goto wlock_again;
- }
-
- /* We have it, say who we are. */
- rw->writer_pc = ((unsigned int)caller);
- rw->writer_cpu = cpu;
- current->thread.smp_lock_count++;
- current->thread.smp_lock_pc = ((unsigned int)caller);
-
- put_cpu();
-}
-
-void _do_write_unlock(rwlock_t *rw, unsigned long caller)
-{
- unsigned long val;
- int stuck = INIT_STUCK;
- int shown = 0;
-
- /* Drop our identity _first_ */
- rw->writer_pc = 0;
- rw->writer_cpu = NO_PROC_ID;
- current->thread.smp_lock_count--;
-wlock_again:
- __asm__ __volatile__(
-" membar #StoreLoad | #LoadLoad\n"
-" mov 1, %%g3\n"
-" sllx %%g3, 63, %%g3\n"
-" ldx [%0], %%g1\n"
-" andn %%g1, %%g3, %%g7\n"
-" casx [%0], %%g1, %%g7\n"
-" membar #StoreLoad | #StoreStore\n"
-" sub %%g1, %%g7, %0\n"
- : "=r" (val)
- : "0" (&(rw->lock))
- : "g3", "g1", "g7", "memory");
- if (val) {
- if (!--stuck) {
- if (shown++ <= 2)
- show_write("write_unlock", rw, caller);
- stuck = INIT_STUCK;
- }
- goto wlock_again;
- }
-}
-
-int _do_write_trylock(rwlock_t *rw, char *str, unsigned long caller)
-{
- unsigned long val;
- int cpu = get_cpu();
-
- /* Try to acuire the write bit. */
- __asm__ __volatile__(
-" mov 1, %%g3\n"
-" sllx %%g3, 63, %%g3\n"
-" ldx [%0], %%g1\n"
-" brlz,pn %%g1, 1f\n"
-" or %%g1, %%g3, %%g7\n"
-" casx [%0], %%g1, %%g7\n"
-" membar #StoreLoad | #StoreStore\n"
-" ba,pt %%xcc, 2f\n"
-" sub %%g1, %%g7, %0\n"
-"1: mov 1, %0\n"
-"2:" : "=r" (val)
- : "0" (&(rw->lock))
- : "g3", "g1", "g7", "memory");
-
- if (val) {
- put_cpu();
- return 0;
- }
-
- if ((rw->lock & ((1UL<<63)-1UL)) != 0UL) {
- /* Readers still around, drop the write
- * lock, return failure.
- */
- __asm__ __volatile__(
-" mov 1, %%g3\n"
-" sllx %%g3, 63, %%g3\n"
-"1: ldx [%0], %%g1\n"
-" andn %%g1, %%g3, %%g7\n"
-" casx [%0], %%g1, %%g7\n"
-" cmp %%g1, %%g7\n"
-" membar #StoreLoad | #StoreStore\n"
-" bne,pn %%xcc, 1b\n"
-" nop"
- : /* no outputs */
- : "r" (&(rw->lock))
- : "g3", "g1", "g7", "cc", "memory");
-
- put_cpu();
-
- return 0;
- }
-
- /* We have it, say who we are. */
- rw->writer_pc = ((unsigned int)caller);
- rw->writer_cpu = cpu;
- current->thread.smp_lock_count++;
- current->thread.smp_lock_pc = ((unsigned int)caller);
-
- put_cpu();
-
- return 1;
-}
-
-#endif /* CONFIG_SMP */