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Diffstat (limited to 'src/vendorcode/cavium/include/bdk/libbdk-hal/bdk-spinlock.h')
| -rw-r--r-- | src/vendorcode/cavium/include/bdk/libbdk-hal/bdk-spinlock.h | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/src/vendorcode/cavium/include/bdk/libbdk-hal/bdk-spinlock.h b/src/vendorcode/cavium/include/bdk/libbdk-hal/bdk-spinlock.h new file mode 100644 index 0000000000..5e34a4f7b9 --- /dev/null +++ b/src/vendorcode/cavium/include/bdk/libbdk-hal/bdk-spinlock.h @@ -0,0 +1,146 @@ +/***********************license start*********************************** +* Copyright (c) 2003-2017 Cavium Inc. (support@cavium.com). All rights +* reserved. +* +* +* Redistribution and use in source and binary forms, with or without +* modification, are permitted provided that the following conditions are +* met: +* +* * Redistributions of source code must retain the above copyright +* notice, this list of conditions and the following disclaimer. +* +* * Redistributions in binary form must reproduce the above +* copyright notice, this list of conditions and the following +* disclaimer in the documentation and/or other materials provided +* with the distribution. +* +* * Neither the name of Cavium Inc. nor the names of +* its contributors may be used to endorse or promote products +* derived from this software without specific prior written +* permission. +* +* This Software, including technical data, may be subject to U.S. export +* control laws, including the U.S. Export Administration Act and its +* associated regulations, and may be subject to export or import +* regulations in other countries. +* +* TO THE MAXIMUM EXTENT PERMITTED BY LAW, THE SOFTWARE IS PROVIDED "AS IS" +* AND WITH ALL FAULTS AND CAVIUM INC. MAKES NO PROMISES, REPRESENTATIONS OR +* WARRANTIES, EITHER EXPRESS, IMPLIED, STATUTORY, OR OTHERWISE, WITH RESPECT +* TO THE SOFTWARE, INCLUDING ITS CONDITION, ITS CONFORMITY TO ANY +* REPRESENTATION OR DESCRIPTION, OR THE EXISTENCE OF ANY LATENT OR PATENT +* DEFECTS, AND CAVIUM SPECIFICALLY DISCLAIMS ALL IMPLIED (IF ANY) WARRANTIES +* OF TITLE, MERCHANTABILITY, NONINFRINGEMENT, FITNESS FOR A PARTICULAR +* PURPOSE, LACK OF VIRUSES, ACCURACY OR COMPLETENESS, QUIET ENJOYMENT, +* QUIET POSSESSION OR CORRESPONDENCE TO DESCRIPTION. THE ENTIRE RISK +* ARISING OUT OF USE OR PERFORMANCE OF THE SOFTWARE LIES WITH YOU. +***********************license end**************************************/ + +/** + * @file + * + * Implementation of spinlocks. + * + * <hr>$Revision: 49448 $<hr> + * + * @addtogroup hal + * @{ + */ + +/** + * Spinlocks + */ +typedef union +{ + uint64_t combined; + struct + { +#if __BYTE_ORDER == __BIG_ENDIAN + uint32_t ticket; + uint32_t serving; +#else + uint32_t serving; + uint32_t ticket; +#endif + } s; +} bdk_spinlock_t; + +/** + * Initialize a spinlock + * + * @param lock Lock to initialize + */ +static inline void bdk_spinlock_init(bdk_spinlock_t *lock) +{ + asm volatile ("str xzr, [%[b]]" + : "+m" (lock->combined) + : [b] "r" (&lock->combined) + : "memory"); +} + +/** + * Releases lock + * + * @param lock pointer to lock structure + */ +static inline void bdk_spinlock_unlock(bdk_spinlock_t *lock) __attribute__ ((always_inline)); +static inline void bdk_spinlock_unlock(bdk_spinlock_t *lock) +{ + /* Implies a release */ + asm volatile ("stlr %w[v], [%[b]]" + : "+m" (lock->s.serving) + : [v] "r" (lock->s.serving + 1), [b] "r" (&lock->s.serving) + : "memory"); +} + +/** + * Gets lock, spins until lock is taken + * + * @param lock pointer to lock structure + */ +static inline void bdk_spinlock_lock(bdk_spinlock_t *lock) __attribute__ ((always_inline)); +static inline void bdk_spinlock_lock(bdk_spinlock_t *lock) +{ + uint64_t combined; + uint32_t ticket; + uint32_t serving; + + asm volatile ( + "mov %x[serving], 1<<32 \n" + "ldadda %x[serving], %x[combined], [%[ptr]] \n" + "and %x[serving], %x[combined], 0xffffffff \n" + "lsr %x[ticket], %x[combined], 32 \n" + "cmp %x[ticket], %x[serving] \n" + "b.eq 1f \n" + "sevl \n" + "2: wfe \n" + "ldxr %w[serving], [%[ptr2]] \n" + "cmp %x[ticket], %x[serving] \n" + "b.ne 2b \n" + "1: \n" + : [serving] "=&r" (serving), [ticket] "=&r" (ticket), [combined] "=&r" (combined), "+m" (lock->combined) + : [ptr] "r" (&lock->combined), [ptr2] "r" (&lock->s.serving) + : "memory" + ); +} + +/** + * Trys to get the lock, failing if we can't get it immediately + * + * @param lock pointer to lock structure + */ +static inline int bdk_spinlock_trylock(bdk_spinlock_t *lock) __attribute__ ((always_inline)); +static inline int bdk_spinlock_trylock(bdk_spinlock_t *lock) +{ + uint64_t combined = *(volatile uint64_t *)&lock->combined; + uint32_t ticket = combined >> 32; + uint32_t serving = (uint32_t)combined; + if (ticket != serving) + return -1; + uint64_t new_combined = combined + (1ull << 32); + bool success = bdk_atomic_compare_and_store64(&lock->combined, combined, new_combined); + return success ? 0 : -1; +} + +/** @} */ |