| .. | .. |
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| 9 | 9 | #define __ASM_BARRIER_H |
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| 10 | 10 | |
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| 11 | 11 | #include <asm/addrspace.h> |
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| 12 | +#include <asm/sync.h> |
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| 12 | 13 | |
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| 13 | | -/* |
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| 14 | | - * Sync types defined by the MIPS architecture (document MD00087 table 6.5) |
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| 15 | | - * These values are used with the sync instruction to perform memory barriers. |
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| 16 | | - * Types of ordering guarantees available through the SYNC instruction: |
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| 17 | | - * - Completion Barriers |
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| 18 | | - * - Ordering Barriers |
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| 19 | | - * As compared to the completion barrier, the ordering barrier is a |
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| 20 | | - * lighter-weight operation as it does not require the specified instructions |
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| 21 | | - * before the SYNC to be already completed. Instead it only requires that those |
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| 22 | | - * specified instructions which are subsequent to the SYNC in the instruction |
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| 23 | | - * stream are never re-ordered for processing ahead of the specified |
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| 24 | | - * instructions which are before the SYNC in the instruction stream. |
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| 25 | | - * This potentially reduces how many cycles the barrier instruction must stall |
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| 26 | | - * before it completes. |
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| 27 | | - * Implementations that do not use any of the non-zero values of stype to define |
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| 28 | | - * different barriers, such as ordering barriers, must make those stype values |
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| 29 | | - * act the same as stype zero. |
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| 30 | | - */ |
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| 14 | +static inline void __sync(void) |
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| 15 | +{ |
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| 16 | + asm volatile(__SYNC(full, always) ::: "memory"); |
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| 17 | +} |
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| 31 | 18 | |
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| 32 | | -/* |
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| 33 | | - * Completion barriers: |
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| 34 | | - * - Every synchronizable specified memory instruction (loads or stores or both) |
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| 35 | | - * that occurs in the instruction stream before the SYNC instruction must be |
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| 36 | | - * already globally performed before any synchronizable specified memory |
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| 37 | | - * instructions that occur after the SYNC are allowed to be performed, with |
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| 38 | | - * respect to any other processor or coherent I/O module. |
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| 39 | | - * |
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| 40 | | - * - The barrier does not guarantee the order in which instruction fetches are |
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| 41 | | - * performed. |
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| 42 | | - * |
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| 43 | | - * - A stype value of zero will always be defined such that it performs the most |
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| 44 | | - * complete set of synchronization operations that are defined.This means |
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| 45 | | - * stype zero always does a completion barrier that affects both loads and |
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| 46 | | - * stores preceding the SYNC instruction and both loads and stores that are |
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| 47 | | - * subsequent to the SYNC instruction. Non-zero values of stype may be defined |
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| 48 | | - * by the architecture or specific implementations to perform synchronization |
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| 49 | | - * behaviors that are less complete than that of stype zero. If an |
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| 50 | | - * implementation does not use one of these non-zero values to define a |
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| 51 | | - * different synchronization behavior, then that non-zero value of stype must |
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| 52 | | - * act the same as stype zero completion barrier. This allows software written |
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| 53 | | - * for an implementation with a lighter-weight barrier to work on another |
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| 54 | | - * implementation which only implements the stype zero completion barrier. |
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| 55 | | - * |
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| 56 | | - * - A completion barrier is required, potentially in conjunction with SSNOP (in |
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| 57 | | - * Release 1 of the Architecture) or EHB (in Release 2 of the Architecture), |
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| 58 | | - * to guarantee that memory reference results are visible across operating |
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| 59 | | - * mode changes. For example, a completion barrier is required on some |
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| 60 | | - * implementations on entry to and exit from Debug Mode to guarantee that |
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| 61 | | - * memory effects are handled correctly. |
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| 62 | | - */ |
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| 19 | +static inline void rmb(void) |
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| 20 | +{ |
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| 21 | + asm volatile(__SYNC(rmb, always) ::: "memory"); |
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| 22 | +} |
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| 23 | +#define rmb rmb |
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| 63 | 24 | |
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| 64 | | -/* |
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| 65 | | - * stype 0 - A completion barrier that affects preceding loads and stores and |
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| 66 | | - * subsequent loads and stores. |
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| 67 | | - * Older instructions which must reach the load/store ordering point before the |
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| 68 | | - * SYNC instruction completes: Loads, Stores |
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| 69 | | - * Younger instructions which must reach the load/store ordering point only |
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| 70 | | - * after the SYNC instruction completes: Loads, Stores |
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| 71 | | - * Older instructions which must be globally performed when the SYNC instruction |
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| 72 | | - * completes: Loads, Stores |
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| 73 | | - */ |
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| 74 | | -#define STYPE_SYNC 0x0 |
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| 25 | +static inline void wmb(void) |
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| 26 | +{ |
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| 27 | + asm volatile(__SYNC(wmb, always) ::: "memory"); |
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| 28 | +} |
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| 29 | +#define wmb wmb |
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| 75 | 30 | |
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| 76 | | -/* |
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| 77 | | - * Ordering barriers: |
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| 78 | | - * - Every synchronizable specified memory instruction (loads or stores or both) |
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| 79 | | - * that occurs in the instruction stream before the SYNC instruction must |
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| 80 | | - * reach a stage in the load/store datapath after which no instruction |
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| 81 | | - * re-ordering is possible before any synchronizable specified memory |
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| 82 | | - * instruction which occurs after the SYNC instruction in the instruction |
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| 83 | | - * stream reaches the same stage in the load/store datapath. |
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| 84 | | - * |
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| 85 | | - * - If any memory instruction before the SYNC instruction in program order, |
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| 86 | | - * generates a memory request to the external memory and any memory |
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| 87 | | - * instruction after the SYNC instruction in program order also generates a |
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| 88 | | - * memory request to external memory, the memory request belonging to the |
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| 89 | | - * older instruction must be globally performed before the time the memory |
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| 90 | | - * request belonging to the younger instruction is globally performed. |
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| 91 | | - * |
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| 92 | | - * - The barrier does not guarantee the order in which instruction fetches are |
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| 93 | | - * performed. |
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| 94 | | - */ |
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| 95 | | - |
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| 96 | | -/* |
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| 97 | | - * stype 0x10 - An ordering barrier that affects preceding loads and stores and |
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| 98 | | - * subsequent loads and stores. |
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| 99 | | - * Older instructions which must reach the load/store ordering point before the |
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| 100 | | - * SYNC instruction completes: Loads, Stores |
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| 101 | | - * Younger instructions which must reach the load/store ordering point only |
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| 102 | | - * after the SYNC instruction completes: Loads, Stores |
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| 103 | | - * Older instructions which must be globally performed when the SYNC instruction |
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| 104 | | - * completes: N/A |
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| 105 | | - */ |
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| 106 | | -#define STYPE_SYNC_MB 0x10 |
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| 107 | | - |
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| 108 | | - |
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| 109 | | -#ifdef CONFIG_CPU_HAS_SYNC |
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| 110 | | -#define __sync() \ |
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| 111 | | - __asm__ __volatile__( \ |
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| 112 | | - ".set push\n\t" \ |
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| 113 | | - ".set noreorder\n\t" \ |
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| 114 | | - ".set mips2\n\t" \ |
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| 115 | | - "sync\n\t" \ |
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| 116 | | - ".set pop" \ |
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| 117 | | - : /* no output */ \ |
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| 118 | | - : /* no input */ \ |
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| 119 | | - : "memory") |
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| 120 | | -#else |
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| 121 | | -#define __sync() do { } while(0) |
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| 122 | | -#endif |
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| 31 | +#define fast_mb() __sync() |
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| 123 | 32 | |
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| 124 | 33 | #define __fast_iob() \ |
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| 125 | 34 | __asm__ __volatile__( \ |
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| .. | .. |
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| 132 | 41 | : "m" (*(int *)CKSEG1) \ |
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| 133 | 42 | : "memory") |
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| 134 | 43 | #ifdef CONFIG_CPU_CAVIUM_OCTEON |
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| 135 | | -# define OCTEON_SYNCW_STR ".set push\n.set arch=octeon\nsyncw\nsyncw\n.set pop\n" |
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| 136 | | -# define __syncw() __asm__ __volatile__(OCTEON_SYNCW_STR : : : "memory") |
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| 137 | | - |
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| 138 | | -# define fast_wmb() __syncw() |
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| 139 | | -# define fast_rmb() barrier() |
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| 140 | | -# define fast_mb() __sync() |
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| 141 | 44 | # define fast_iob() do { } while (0) |
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| 142 | 45 | #else /* ! CONFIG_CPU_CAVIUM_OCTEON */ |
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| 143 | | -# define fast_wmb() __sync() |
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| 144 | | -# define fast_rmb() __sync() |
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| 145 | | -# define fast_mb() __sync() |
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| 146 | 46 | # ifdef CONFIG_SGI_IP28 |
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| 147 | 47 | # define fast_iob() \ |
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| 148 | 48 | __asm__ __volatile__( \ |
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| .. | .. |
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| 178 | 78 | |
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| 179 | 79 | #endif /* !CONFIG_CPU_HAS_WB */ |
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| 180 | 80 | |
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| 181 | | -#define wmb() fast_wmb() |
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| 182 | | -#define rmb() fast_rmb() |
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| 183 | | - |
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| 184 | 81 | #if defined(CONFIG_WEAK_ORDERING) |
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| 185 | | -# ifdef CONFIG_CPU_CAVIUM_OCTEON |
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| 186 | | -# define __smp_mb() __sync() |
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| 187 | | -# define __smp_rmb() barrier() |
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| 188 | | -# define __smp_wmb() __syncw() |
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| 189 | | -# else |
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| 190 | | -# define __smp_mb() __asm__ __volatile__("sync" : : :"memory") |
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| 191 | | -# define __smp_rmb() __asm__ __volatile__("sync" : : :"memory") |
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| 192 | | -# define __smp_wmb() __asm__ __volatile__("sync" : : :"memory") |
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| 193 | | -# endif |
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| 82 | +# define __smp_mb() __sync() |
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| 83 | +# define __smp_rmb() rmb() |
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| 84 | +# define __smp_wmb() wmb() |
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| 194 | 85 | #else |
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| 195 | | -#define __smp_mb() barrier() |
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| 196 | | -#define __smp_rmb() barrier() |
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| 197 | | -#define __smp_wmb() barrier() |
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| 86 | +# define __smp_mb() barrier() |
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| 87 | +# define __smp_rmb() barrier() |
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| 88 | +# define __smp_wmb() barrier() |
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| 198 | 89 | #endif |
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| 199 | 90 | |
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| 91 | +/* |
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| 92 | + * When LL/SC does imply order, it must also be a compiler barrier to avoid the |
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| 93 | + * compiler from reordering where the CPU will not. When it does not imply |
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| 94 | + * order, the compiler is also free to reorder across the LL/SC loop and |
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| 95 | + * ordering will be done by smp_llsc_mb() and friends. |
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| 96 | + */ |
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| 200 | 97 | #if defined(CONFIG_WEAK_REORDERING_BEYOND_LLSC) && defined(CONFIG_SMP) |
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| 201 | | -#define __WEAK_LLSC_MB " sync \n" |
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| 98 | +# define __WEAK_LLSC_MB sync |
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| 99 | +# define smp_llsc_mb() \ |
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| 100 | + __asm__ __volatile__(__stringify(__WEAK_LLSC_MB) : : :"memory") |
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| 101 | +# define __LLSC_CLOBBER |
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| 202 | 102 | #else |
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| 203 | | -#define __WEAK_LLSC_MB " \n" |
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| 103 | +# define __WEAK_LLSC_MB |
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| 104 | +# define smp_llsc_mb() do { } while (0) |
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| 105 | +# define __LLSC_CLOBBER "memory" |
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| 204 | 106 | #endif |
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| 205 | | - |
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| 206 | | -#define smp_llsc_mb() __asm__ __volatile__(__WEAK_LLSC_MB : : :"memory") |
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| 207 | 107 | |
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| 208 | 108 | #ifdef CONFIG_CPU_CAVIUM_OCTEON |
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| 209 | 109 | #define smp_mb__before_llsc() smp_wmb() |
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| .. | .. |
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| 219 | 119 | #define nudge_writes() mb() |
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| 220 | 120 | #endif |
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| 221 | 121 | |
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| 222 | | -#define __smp_mb__before_atomic() __smp_mb__before_llsc() |
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| 122 | +/* |
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| 123 | + * In the Loongson3 LL/SC workaround case, all of our LL/SC loops already have |
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| 124 | + * a completion barrier immediately preceding the LL instruction. Therefore we |
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| 125 | + * can skip emitting a barrier from __smp_mb__before_atomic(). |
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| 126 | + */ |
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| 127 | +#ifdef CONFIG_CPU_LOONGSON3_WORKAROUNDS |
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| 128 | +# define __smp_mb__before_atomic() |
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| 129 | +#else |
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| 130 | +# define __smp_mb__before_atomic() __smp_mb__before_llsc() |
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| 131 | +#endif |
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| 132 | + |
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| 223 | 133 | #define __smp_mb__after_atomic() smp_llsc_mb() |
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| 224 | 134 | |
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| 135 | +static inline void sync_ginv(void) |
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| 136 | +{ |
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| 137 | + asm volatile(__SYNC(ginv, always)); |
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| 138 | +} |
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| 139 | + |
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| 225 | 140 | #include <asm-generic/barrier.h> |
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| 226 | 141 | |
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| 227 | 142 | #endif /* __ASM_BARRIER_H */ |
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