/* SPDX-License-Identifier: GPL-2.0 */ /* * R/W semaphores for ia64 * * Copyright (C) 2003 Ken Chen <kenneth.w.chen@intel.com> * Copyright (C) 2003 Asit Mallick <asit.k.mallick@intel.com> * Copyright (C) 2005 Christoph Lameter <cl@linux.com> * * Based on asm-i386/rwsem.h and other architecture implementation. * * The MSW of the count is the negated number of active writers and * waiting lockers, and the LSW is the total number of active locks. * * The lock count is initialized to 0 (no active and no waiting lockers). * * When a writer subtracts WRITE_BIAS, it'll get 0xffffffff00000001 for * the case of an uncontended lock. Readers increment by 1 and see a positive * value when uncontended, negative if there are writers (and maybe) readers * waiting (in which case it goes to sleep). */ #ifndef _ASM_IA64_RWSEM_H #define _ASM_IA64_RWSEM_H #ifndef _LINUX_RWSEM_H #error "Please don't include <asm/rwsem.h> directly, use <linux/rwsem.h> instead." #endif #include <asm/intrinsics.h> #define RWSEM_UNLOCKED_VALUE __IA64_UL_CONST(0x0000000000000000) #define RWSEM_ACTIVE_BIAS (1L) #define RWSEM_ACTIVE_MASK (0xffffffffL) #define RWSEM_WAITING_BIAS (-0x100000000L) #define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS #define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) /* * lock for reading */ static inline int ___down_read (struct rw_semaphore *sem) { long result = ia64_fetchadd8_acq((unsigned long *)&sem->count.counter, 1); return (result < 0); } static inline void __down_read (struct rw_semaphore *sem) { if (___down_read(sem)) rwsem_down_read_failed(sem); } static inline int __down_read_killable (struct rw_semaphore *sem) { if (___down_read(sem)) if (IS_ERR(rwsem_down_read_failed_killable(sem))) return -EINTR; return 0; } /* * lock for writing */ static inline long ___down_write (struct rw_semaphore *sem) { long old, new; do { old = atomic_long_read(&sem->count); new = old + RWSEM_ACTIVE_WRITE_BIAS; } while (atomic_long_cmpxchg_acquire(&sem->count, old, new) != old); return old; } static inline void __down_write (struct rw_semaphore *sem) { if (___down_write(sem)) rwsem_down_write_failed(sem); } static inline int __down_write_killable (struct rw_semaphore *sem) { if (___down_write(sem)) { if (IS_ERR(rwsem_down_write_failed_killable(sem))) return -EINTR; } return 0; } /* * unlock after reading */ static inline void __up_read (struct rw_semaphore *sem) { long result = ia64_fetchadd8_rel((unsigned long *)&sem->count.counter, -1); if (result < 0 && (--result & RWSEM_ACTIVE_MASK) == 0) rwsem_wake(sem); } /* * unlock after writing */ static inline void __up_write (struct rw_semaphore *sem) { long old, new; do { old = atomic_long_read(&sem->count); new = old - RWSEM_ACTIVE_WRITE_BIAS; } while (atomic_long_cmpxchg_release(&sem->count, old, new) != old); if (new < 0 && (new & RWSEM_ACTIVE_MASK) == 0) rwsem_wake(sem); } /* * trylock for reading -- returns 1 if successful, 0 if contention */ static inline int __down_read_trylock (struct rw_semaphore *sem) { long tmp; while ((tmp = atomic_long_read(&sem->count)) >= 0) { if (tmp == atomic_long_cmpxchg_acquire(&sem->count, tmp, tmp+1)) { return 1; } } return 0; } /* * trylock for writing -- returns 1 if successful, 0 if contention */ static inline int __down_write_trylock (struct rw_semaphore *sem) { long tmp = atomic_long_cmpxchg_acquire(&sem->count, RWSEM_UNLOCKED_VALUE, RWSEM_ACTIVE_WRITE_BIAS); return tmp == RWSEM_UNLOCKED_VALUE; } /* * downgrade write lock to read lock */ static inline void __downgrade_write (struct rw_semaphore *sem) { long old, new; do { old = atomic_long_read(&sem->count); new = old - RWSEM_WAITING_BIAS; } while (atomic_long_cmpxchg_release(&sem->count, old, new) != old); if (old < 0) rwsem_downgrade_wake(sem); } #endif /* _ASM_IA64_RWSEM_H */
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acenv.h | File | 1.27 KB | 0644 |
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acpi-ext.h | File | 590 B | 0644 |
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acpi.h | File | 4.1 KB | 0644 |
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agp.h | File | 857 B | 0644 |
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asm-offsets.h | File | 35 B | 0644 |
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asm-prototypes.h | File | 890 B | 0644 |
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asmmacro.h | File | 3.29 KB | 0644 |
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atomic.h | File | 9.47 KB | 0644 |
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barrier.h | File | 2.36 KB | 0644 |
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bitops.h | File | 10.84 KB | 0644 |
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bug.h | File | 404 B | 0644 |
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cache.h | File | 771 B | 0644 |
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cacheflush.h | File | 1.71 KB | 0644 |
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checksum.h | File | 2.1 KB | 0644 |
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clocksource.h | File | 276 B | 0644 |
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cpu.h | File | 456 B | 0644 |
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cputime.h | File | 855 B | 0644 |
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current.h | File | 418 B | 0644 |
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cyclone.h | File | 442 B | 0644 |
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delay.h | File | 1.7 KB | 0644 |
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device.h | File | 323 B | 0644 |
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div64.h | File | 31 B | 0644 |
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dma-mapping.h | File | 1.17 KB | 0644 |
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dma.h | File | 466 B | 0644 |
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dmi.h | File | 343 B | 0644 |
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early_ioremap.h | File | 428 B | 0644 |
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elf.h | File | 9.83 KB | 0644 |
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emergency-restart.h | File | 149 B | 0644 |
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esi.h | File | 887 B | 0644 |
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exception.h | File | 1.13 KB | 0644 |
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export.h | File | 115 B | 0644 |
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extable.h | File | 330 B | 0644 |
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fb.h | File | 569 B | 0644 |
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fpswa.h | File | 1.88 KB | 0644 |
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ftrace.h | File | 748 B | 0644 |
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futex.h | File | 2.56 KB | 0644 |
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hardirq.h | File | 564 B | 0644 |
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hpsim.h | File | 364 B | 0644 |
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hugetlb.h | File | 1.67 KB | 0644 |
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hw_irq.h | File | 6.33 KB | 0644 |
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idle.h | File | 200 B | 0644 |
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intrinsics.h | File | 306 B | 0644 |
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io.h | File | 11.77 KB | 0644 |
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iommu.h | File | 555 B | 0644 |
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iommu_table.h | File | 175 B | 0644 |
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iosapic.h | File | 3.16 KB | 0644 |
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irq.h | File | 1.02 KB | 0644 |
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irq_regs.h | File | 34 B | 0644 |
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irq_remapping.h | File | 142 B | 0644 |
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irqflags.h | File | 2.11 KB | 0644 |
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kdebug.h | File | 1.64 KB | 0644 |
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kexec.h | File | 1.57 KB | 0644 |
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kmap_types.h | File | 260 B | 0644 |
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kprobes.h | File | 3.82 KB | 0644 |
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kregs.h | File | 6.73 KB | 0644 |
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libata-portmap.h | File | 225 B | 0644 |
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linkage.h | File | 398 B | 0644 |
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local.h | File | 31 B | 0644 |
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local64.h | File | 33 B | 0644 |
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machvec.h | File | 12.1 KB | 0644 |
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machvec_dig.h | File | 449 B | 0644 |
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machvec_dig_vtd.h | File | 558 B | 0644 |
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machvec_hpsim.h | File | 544 B | 0644 |
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machvec_hpzx1.h | File | 544 B | 0644 |
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machvec_hpzx1_swiotlb.h | File | 632 B | 0644 |
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machvec_init.h | File | 1.33 KB | 0644 |
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machvec_uv.h | File | 684 B | 0644 |
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mca.h | File | 5.91 KB | 0644 |
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mca_asm.h | File | 7.18 KB | 0644 |
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meminit.h | File | 2.24 KB | 0644 |
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mman.h | File | 432 B | 0644 |
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mmu.h | File | 374 B | 0644 |
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mmu_context.h | File | 5.29 KB | 0644 |
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mmzone.h | File | 1.1 KB | 0644 |
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module.h | File | 1.1 KB | 0644 |
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parport.h | File | 534 B | 0644 |
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patch.h | File | 1.19 KB | 0644 |
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percpu.h | File | 1.32 KB | 0644 |
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perfmon.h | File | 4.33 KB | 0644 |
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pgalloc.h | File | 2.84 KB | 0644 |
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pgtable.h | File | 20.92 KB | 0644 |
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processor.h | File | 17.98 KB | 0644 |
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ptrace.h | File | 5.2 KB | 0644 |
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rwsem.h | File | 3.82 KB | 0644 |
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sal.h | File | 26.51 KB | 0644 |
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sections.h | File | 1.35 KB | 0644 |
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segment.h | File | 162 B | 0644 |
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serial.h | File | 446 B | 0644 |
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shmparam.h | File | 445 B | 0644 |
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signal.h | File | 749 B | 0644 |
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smp.h | File | 3.21 KB | 0644 |
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sparsemem.h | File | 621 B | 0644 |
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spinlock.h | File | 6.92 KB | 0644 |
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spinlock_types.h | File | 475 B | 0644 |
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string.h | File | 659 B | 0644 |
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swiotlb.h | File | 344 B | 0644 |
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switch_to.h | File | 2.89 KB | 0644 |
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syscall.h | File | 2.06 KB | 0644 |
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termios.h | File | 1.88 KB | 0644 |
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thread_info.h | File | 4.66 KB | 0644 |
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timex.h | File | 1.47 KB | 0644 |
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tlb.h | File | 8.42 KB | 0644 |
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tlbflush.h | File | 2.33 KB | 0644 |
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topology.h | File | 1.58 KB | 0644 |
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types.h | File | 828 B | 0644 |
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uaccess.h | File | 9.86 KB | 0644 |
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unaligned.h | File | 337 B | 0644 |
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uncached.h | File | 463 B | 0644 |
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unistd.h | File | 1.45 KB | 0644 |
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unwind.h | File | 5.74 KB | 0644 |
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user.h | File | 2.25 KB | 0644 |
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vga.h | File | 657 B | 0644 |
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