diff options
Diffstat (limited to 'linux/src/include/asm-i386/spinlock.h')
| -rw-r--r-- | linux/src/include/asm-i386/spinlock.h | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/linux/src/include/asm-i386/spinlock.h b/linux/src/include/asm-i386/spinlock.h new file mode 100644 index 0000000..18119d4 --- /dev/null +++ b/linux/src/include/asm-i386/spinlock.h @@ -0,0 +1,262 @@ +#ifndef __ASM_SPINLOCK_H +#define __ASM_SPINLOCK_H + +#ifndef __SMP__ + +#define DEBUG_SPINLOCKS 0 /* 0 == no debugging, 1 == maintain lock state, 2 == full debug */ + +#if (DEBUG_SPINLOCKS < 1) + +/* + * Your basic spinlocks, allowing only a single CPU anywhere + * + * Gcc-2.7.x has a nasty bug with empty initializers. + */ +#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8) + typedef struct { } spinlock_t; + #define SPIN_LOCK_UNLOCKED (spinlock_t) { } +#else + typedef struct { int gcc_is_buggy; } spinlock_t; + #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } +#endif + +#define spin_lock_init(lock) do { } while(0) +#define spin_lock(lock) (void)(lock) /* Not "unused variable". */ +#define spin_trylock(lock) (1) +#define spin_unlock_wait(lock) do { } while(0) +#define spin_unlock(lock) do { } while(0) +#define spin_lock_irq(lock) cli() +#define spin_unlock_irq(lock) sti() + +#define spin_lock_irqsave(lock, flags) \ + do { save_flags(flags); cli(); } while (0) +#define spin_unlock_irqrestore(lock, flags) \ + restore_flags(flags) + +#elif (DEBUG_SPINLOCKS < 2) + +typedef struct { + volatile unsigned int lock; +} spinlock_t; +#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } + +#define spin_lock_init(x) do { (x)->lock = 0; } while (0) +#define spin_trylock(lock) (!test_and_set_bit(0,(lock))) + +#define spin_lock(x) do { (x)->lock = 1; } while (0) +#define spin_unlock_wait(x) do { } while (0) +#define spin_unlock(x) do { (x)->lock = 0; } while (0) +#define spin_lock_irq(x) do { cli(); spin_lock(x); } while (0) +#define spin_unlock_irq(x) do { spin_unlock(x); sti(); } while (0) + +#define spin_lock_irqsave(x, flags) \ + do { save_flags(flags); spin_lock_irq(x); } while (0) +#define spin_unlock_irqrestore(x, flags) \ + do { spin_unlock(x); restore_flags(flags); } while (0) + +#else /* (DEBUG_SPINLOCKS >= 2) */ + +typedef struct { + volatile unsigned int lock; + volatile unsigned int babble; + const char *module; +} spinlock_t; +#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 25, __BASE_FILE__ } + +#include <linux/kernel.h> + +#define spin_lock_init(x) do { (x)->lock = 0; } while (0) +#define spin_trylock(lock) (!test_and_set_bit(0,(lock))) + +#define spin_lock(x) do {unsigned long __spinflags; save_flags(__spinflags); cli(); if ((x)->lock&&(x)->babble) {printk("%s:%d: spin_lock(%s:%p) already locked\n", __BASE_FILE__,__LINE__, (x)->module, (x));(x)->babble--;} (x)->lock = 1; restore_flags(__spinflags);} while (0) +#define spin_unlock_wait(x) do {unsigned long __spinflags; save_flags(__spinflags); cli(); if ((x)->lock&&(x)->babble) {printk("%s:%d: spin_unlock_wait(%s:%p) deadlock\n", __BASE_FILE__,__LINE__, (x)->module, (x));(x)->babble--;} restore_flags(__spinflags);} while (0) +#define spin_unlock(x) do {unsigned long __spinflags; save_flags(__spinflags); cli(); if (!(x)->lock&&(x)->babble) {printk("%s:%d: spin_unlock(%s:%p) not locked\n", __BASE_FILE__,__LINE__, (x)->module, (x));(x)->babble--;} (x)->lock = 0; restore_flags(__spinflags);} while (0) +#define spin_lock_irq(x) do {cli(); if ((x)->lock&&(x)->babble) {printk("%s:%d: spin_lock_irq(%s:%p) already locked\n", __BASE_FILE__,__LINE__, (x)->module, (x));(x)->babble--;} (x)->lock = 1;} while (0) +#define spin_unlock_irq(x) do {cli(); if (!(x)->lock&&(x)->babble) {printk("%s:%d: spin_unlock_irq(%s:%p) not locked\n", __BASE_FILE__,__LINE__, (x)->module, (x));(x)->babble--;} (x)->lock = 0; sti();} while (0) + +#define spin_lock_irqsave(x,flags) do {save_flags(flags); cli(); if ((x)->lock&&(x)->babble) {printk("%s:%d: spin_lock_irqsave(%s:%p) already locked\n", __BASE_FILE__,__LINE__, (x)->module, (x));(x)->babble--;} (x)->lock = 1;} while (0) +#define spin_unlock_irqrestore(x,flags) do {cli(); if (!(x)->lock&&(x)->babble) {printk("%s:%d: spin_unlock_irqrestore(%s:%p) not locked\n", __BASE_FILE__,__LINE__, (x)->module, (x));(x)->babble--;} (x)->lock = 0; restore_flags(flags);} while (0) + +#endif /* DEBUG_SPINLOCKS */ + +/* + * Read-write spinlocks, allowing multiple readers + * but only one writer. + * + * NOTE! it is quite common to have readers in interrupts + * but no interrupt writers. For those circumstances we + * can "mix" irq-safe locks - any writer needs to get a + * irq-safe write-lock, but readers can get non-irqsafe + * read-locks. + * + * Gcc-2.7.x has a nasty bug with empty initializers. + */ +#if (__GNUC__ > 2) || (__GNUC__ == 2 && __GNUC_MINOR__ >= 8) + typedef struct { } rwlock_t; + #define RW_LOCK_UNLOCKED (rwlock_t) { } +#else + typedef struct { int gcc_is_buggy; } rwlock_t; + #define RW_LOCK_UNLOCKED (rwlock_t) { 0 } +#endif + +#define read_lock(lock) (void)(lock) /* Not "unused variable." */ +#define read_unlock(lock) do { } while(0) +#define write_lock(lock) (void)(lock) /* Not "unused variable." */ +#define write_unlock(lock) do { } while(0) +#define read_lock_irq(lock) cli() +#define read_unlock_irq(lock) sti() +#define write_lock_irq(lock) cli() +#define write_unlock_irq(lock) sti() + +#define read_lock_irqsave(lock, flags) \ + do { save_flags(flags); cli(); } while (0) +#define read_unlock_irqrestore(lock, flags) \ + restore_flags(flags) +#define write_lock_irqsave(lock, flags) \ + do { save_flags(flags); cli(); } while (0) +#define write_unlock_irqrestore(lock, flags) \ + restore_flags(flags) + +#else /* __SMP__ */ + +/* + * Your basic spinlocks, allowing only a single CPU anywhere + */ + +typedef struct { + volatile unsigned int lock; +} spinlock_t; + +#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } + +#define spin_lock_init(x) do { (x)->lock = 0; } while(0) +/* + * Simple spin lock operations. There are two variants, one clears IRQ's + * on the local processor, one does not. + * + * We make no fairness assumptions. They have a cost. + */ + +#define spin_unlock_wait(x) do { barrier(); } while(((volatile spinlock_t *)(x))->lock) + +typedef struct { unsigned long a[100]; } __dummy_lock_t; +#define __dummy_lock(lock) (*(__dummy_lock_t *)(lock)) + +/* + * Intel PIV would benefit from using 'rep nop' here but on older + * processors and non intel it is listed as 'undefined' so cannot be + * blindly used. On 2.4 we should add a PIV CPU type for this one. + */ +#define spin_lock_string \ + "\n1:\t" \ + "lock ; btsl $0,%0\n\t" \ + "jc 2f\n" \ + ".section .text.lock,\"ax\"\n" \ + "2:\t" \ + "rep; nop\n\t" \ + "testb $1,%0\n\t" \ + "jne 2b\n\t" \ + "jmp 1b\n" \ + ".previous" + +#define spin_unlock_string \ + "lock ; btrl $0,%0" + +#define spin_lock(lock) \ +__asm__ __volatile__( \ + spin_lock_string \ + :"=m" (__dummy_lock(lock))) + +#define spin_unlock(lock) \ +__asm__ __volatile__( \ + spin_unlock_string \ + :"=m" (__dummy_lock(lock))) + +#define spin_trylock(lock) (!test_and_set_bit(0,(lock))) + +#define spin_lock_irq(lock) \ + do { __cli(); spin_lock(lock); } while (0) + +#define spin_unlock_irq(lock) \ + do { spin_unlock(lock); __sti(); } while (0) + +#define spin_lock_irqsave(lock, flags) \ + do { __save_flags(flags); __cli(); spin_lock(lock); } while (0) + +#define spin_unlock_irqrestore(lock, flags) \ + do { spin_unlock(lock); __restore_flags(flags); } while (0) + +/* + * Read-write spinlocks, allowing multiple readers + * but only one writer. + * + * NOTE! it is quite common to have readers in interrupts + * but no interrupt writers. For those circumstances we + * can "mix" irq-safe locks - any writer needs to get a + * irq-safe write-lock, but readers can get non-irqsafe + * read-locks. + */ +typedef struct { + volatile unsigned int lock; + unsigned long previous; +} rwlock_t; + +#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 } + +/* + * On x86, we implement read-write locks as a 32-bit counter + * with the high bit (sign) being the "write" bit. + * + * The inline assembly is non-obvious. Think about it. + */ +#define read_lock(rw) \ + asm volatile("\n1:\t" \ + "lock ; incl %0\n\t" \ + "js 2f\n" \ + ".section .text.lock,\"ax\"\n" \ + "2:\tlock ; decl %0\n" \ + "3:\trep; nop\n\t" \ + "cmpl $0,%0\n\t" \ + "js 3b\n\t" \ + "jmp 1b\n" \ + ".previous" \ + :"=m" (__dummy_lock(&(rw)->lock))) + +#define read_unlock(rw) \ + asm volatile("lock ; decl %0" \ + :"=m" (__dummy_lock(&(rw)->lock))) + +#define write_lock(rw) \ + asm volatile("\n1:\t" \ + "lock ; btsl $31,%0\n\t" \ + "jc 4f\n" \ + "2:\ttestl $0x7fffffff,%0\n\t" \ + "jne 3f\n" \ + ".section .text.lock,\"ax\"\n" \ + "3:\tlock ; btrl $31,%0\n" \ + "4:\trep; nop\n\t" \ + "cmp $0,%0\n\t" \ + "jne 4b\n\t" \ + "jmp 1b\n" \ + ".previous" \ + :"=m" (__dummy_lock(&(rw)->lock))) + +#define write_unlock(rw) \ + asm volatile("lock ; btrl $31,%0":"=m" (__dummy_lock(&(rw)->lock))) + +#define read_lock_irq(lock) do { __cli(); read_lock(lock); } while (0) +#define read_unlock_irq(lock) do { read_unlock(lock); __sti(); } while (0) +#define write_lock_irq(lock) do { __cli(); write_lock(lock); } while (0) +#define write_unlock_irq(lock) do { write_unlock(lock); __sti(); } while (0) + +#define read_lock_irqsave(lock, flags) \ + do { __save_flags(flags); __cli(); read_lock(lock); } while (0) +#define read_unlock_irqrestore(lock, flags) \ + do { read_unlock(lock); __restore_flags(flags); } while (0) +#define write_lock_irqsave(lock, flags) \ + do { __save_flags(flags); __cli(); write_lock(lock); } while (0) +#define write_unlock_irqrestore(lock, flags) \ + do { write_unlock(lock); __restore_flags(flags); } while (0) + +#endif /* __SMP__ */ +#endif /* __ASM_SPINLOCK_H */ |