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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 | #ifndef __LINUX_SPINLOCK_H #define __LINUX_SPINLOCK_H #include <linux/config.h> #include <linux/linkage.h> #include <linux/compiler.h> #include <linux/thread_info.h> #include <linux/kernel.h> /* * These are the generic versions of the spinlocks and read-write * locks.. */ #define spin_lock_irqsave(lock, flags) do { local_irq_save(flags); spin_lock(lock); } while (0) #define spin_lock_irq(lock) do { local_irq_disable(); spin_lock(lock); } while (0) #define spin_lock_bh(lock) do { local_bh_disable(); spin_lock(lock); } while (0) #define read_lock_irqsave(lock, flags) do { local_irq_save(flags); read_lock(lock); } while (0) #define read_lock_irq(lock) do { local_irq_disable(); read_lock(lock); } while (0) #define read_lock_bh(lock) do { local_bh_disable(); read_lock(lock); } while (0) #define write_lock_irqsave(lock, flags) do { local_irq_save(flags); write_lock(lock); } while (0) #define write_lock_irq(lock) do { local_irq_disable(); write_lock(lock); } while (0) #define write_lock_bh(lock) do { local_bh_disable(); write_lock(lock); } while (0) #define spin_unlock_irqrestore(lock, flags) do { spin_unlock(lock); local_irq_restore(flags); } while (0) #define spin_unlock_irq(lock) do { spin_unlock(lock); local_irq_enable(); } while (0) #define spin_unlock_bh(lock) do { spin_unlock(lock); local_bh_enable(); } while (0) #define read_unlock_irqrestore(lock, flags) do { read_unlock(lock); local_irq_restore(flags); } while (0) #define read_unlock_irq(lock) do { read_unlock(lock); local_irq_enable(); } while (0) #define read_unlock_bh(lock) do { read_unlock(lock); local_bh_enable(); } while (0) #define write_unlock_irqrestore(lock, flags) do { write_unlock(lock); local_irq_restore(flags); } while (0) #define write_unlock_irq(lock) do { write_unlock(lock); local_irq_enable(); } while (0) #define write_unlock_bh(lock) do { write_unlock(lock); local_bh_enable(); } while (0) #define spin_trylock_bh(lock) ({ int __r; local_bh_disable();\ __r = spin_trylock(lock); \ if (!__r) local_bh_enable(); \ __r; }) /* Must define these before including other files, inline functions need them */ #include <linux/stringify.h> #define LOCK_SECTION_NAME \ ".text.lock." __stringify(KBUILD_BASENAME) #define LOCK_SECTION_START(extra) \ ".subsection 1\n\t" \ extra \ ".ifndef " LOCK_SECTION_NAME "\n\t" \ LOCK_SECTION_NAME ":\n\t" \ ".endif\n\t" #define LOCK_SECTION_END \ ".previous\n\t" #ifdef CONFIG_SMP #include <asm/spinlock.h> #elif !defined(spin_lock_init) /* !SMP and spin_lock_init not previously defined (e.g. by including asm/spinlock.h */ #define DEBUG_SPINLOCKS 0 /* 0 == no debugging, 1 == maintain lock state, 2 == full debug */ #if (DEBUG_SPINLOCKS < 1) #ifndef CONFIG_PREEMPT #define atomic_dec_and_lock(atomic,lock) atomic_dec_and_test(atomic) #define ATOMIC_DEC_AND_LOCK #endif /* * Your basic spinlocks, allowing only a single CPU anywhere * * Most gcc versions have a nasty bug with empty initializers. */ #if (__GNUC__ > 2) 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 { (void)(lock); } while(0) #define _raw_spin_lock(lock) (void)(lock) /* Not "unused variable". */ #define spin_is_locked(lock) ((void)(lock), 0) #define _raw_spin_trylock(lock) ((void)(lock), 1) #define spin_unlock_wait(lock) do { (void)(lock); } while(0) #define _raw_spin_unlock(lock) do { (void)(lock); } while(0) #elif (DEBUG_SPINLOCKS < 2) typedef struct { volatile unsigned long lock; } spinlock_t; #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } #define spin_lock_init(x) do { (x)->lock = 0; } while (0) #define spin_is_locked(lock) (test_bit(0,(lock))) #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) #else /* (DEBUG_SPINLOCKS >= 2) */ typedef struct { volatile unsigned long 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_is_locked(lock) (test_bit(0,(lock))) #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) #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. * * Most gcc versions have a nasty bug with empty initializers. */ #if (__GNUC__ > 2) 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 rwlock_init(lock) do { } while(0) #define _raw_read_lock(lock) (void)(lock) /* Not "unused variable". */ #define _raw_read_unlock(lock) do { } while(0) #define _raw_write_lock(lock) (void)(lock) /* Not "unused variable". */ #define _raw_write_unlock(lock) do { } while(0) #endif /* !SMP */ #ifdef CONFIG_PREEMPT asmlinkage void preempt_schedule(void); #define preempt_get_count() (current_thread_info()->preempt_count) #define preempt_disable() \ do { \ ++current_thread_info()->preempt_count; \ barrier(); \ } while (0) #define preempt_enable_no_resched() \ do { \ --current_thread_info()->preempt_count; \ barrier(); \ } while (0) #define preempt_enable() \ do { \ --current_thread_info()->preempt_count; \ barrier(); \ if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \ preempt_schedule(); \ } while (0) #define spin_lock(lock) \ do { \ preempt_disable(); \ _raw_spin_lock(lock); \ } while(0) #define spin_trylock(lock) ({preempt_disable(); _raw_spin_trylock(lock) ? \ 1 : ({preempt_enable(); 0;});}) #define spin_unlock(lock) \ do { \ _raw_spin_unlock(lock); \ preempt_enable(); \ } while (0) #define read_lock(lock) ({preempt_disable(); _raw_read_lock(lock);}) #define read_unlock(lock) ({_raw_read_unlock(lock); preempt_enable();}) #define write_lock(lock) ({preempt_disable(); _raw_write_lock(lock);}) #define write_unlock(lock) ({_raw_write_unlock(lock); preempt_enable();}) #define write_trylock(lock) ({preempt_disable();_raw_write_trylock(lock) ? \ 1 : ({preempt_enable(); 0;});}) #else #define preempt_get_count() (0) #define preempt_disable() do { } while (0) #define preempt_enable_no_resched() do {} while(0) #define preempt_enable() do { } while (0) #define spin_lock(lock) _raw_spin_lock(lock) #define spin_trylock(lock) _raw_spin_trylock(lock) #define spin_unlock(lock) _raw_spin_unlock(lock) #define read_lock(lock) _raw_read_lock(lock) #define read_unlock(lock) _raw_read_unlock(lock) #define write_lock(lock) _raw_write_lock(lock) #define write_unlock(lock) _raw_write_unlock(lock) #define write_trylock(lock) _raw_write_trylock(lock) #endif /* "lock on reference count zero" */ #ifndef ATOMIC_DEC_AND_LOCK #include <asm/atomic.h> extern int atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); #endif #endif /* __LINUX_SPINLOCK_H */ |