[06dcaf0] | 1 | /* |
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| 2 | * COPYRIGHT (c) 1989-2011. |
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| 3 | * On-Line Applications Research Corporation (OAR). |
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| 4 | * |
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| 5 | * The license and distribution terms for this file may be |
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| 6 | * found in the file LICENSE in this distribution or at |
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| 7 | * http://www.rtems.com/license/LICENSE. |
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| 8 | * |
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| 9 | * $Id$ |
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| 10 | */ |
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| 11 | |
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| 12 | #if HAVE_CONFIG_H |
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| 13 | #include "config.h" |
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| 14 | #endif |
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| 15 | |
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| 16 | #include <rtems/system.h> |
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| 17 | #include <rtems/score/smplock.h> |
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[a8d7e2ab] | 18 | #include <rtems/score/smp.h> |
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[dad36c52] | 19 | #include <rtems/score/isr.h> |
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[06dcaf0] | 20 | |
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[dad36c52] | 21 | /* |
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| 22 | * Some debug stuff that is being left in, but disabled. This will keep |
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| 23 | * a log of lock/unlock sequences that can be printed out when the |
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| 24 | * lockcount appears to have gotten off track. |
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| 25 | */ |
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| 26 | /* #define SMPLOCK_DEBUG */ |
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| 27 | #if defined (SMPLOCK_DEBUG) |
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| 28 | #include <rtems/score/thread.h> |
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[a8d7e2ab] | 29 | #include <rtems/bspIo.h> |
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[dad36c52] | 30 | #include <rtems/score/percpu.h> |
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| 31 | #if (0) |
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| 32 | #define ENABLE_ONESHOT_DEBUG_LOGGING |
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| 33 | #else |
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| 34 | #define ENABLE_LOOPED_DEBUG_LOGGING |
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| 35 | #endif |
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| 36 | #define ENABLE_DEBUG_LOGGING |
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[a8d7e2ab] | 37 | #endif |
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| 38 | |
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[dad36c52] | 39 | /* |
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| 40 | * Prototypes and structures used in the debug lock/unlock error log. |
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| 41 | */ |
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| 42 | #if defined(ENABLE_DEBUG_LOGGING) |
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| 43 | typedef struct { |
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| 44 | char action; |
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| 45 | char lock; |
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| 46 | char cpu; |
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| 47 | char count; |
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| 48 | uint32_t nest_level; |
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| 49 | void *ret1; |
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| 50 | void *ret2; |
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| 51 | void *ret3; |
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| 52 | void *ret4; |
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| 53 | } debug_spinlog_t; |
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| 54 | |
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| 55 | extern void start(void); |
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| 56 | extern void _fini(void); |
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| 57 | |
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| 58 | #define DEBUG_SPINLOG_MAX 1024 |
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| 59 | debug_spinlog_t DEBUG_SPINLOG[DEBUG_SPINLOG_MAX]; |
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| 60 | int DEBUG_SPINLOG_INDEX = 0; |
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| 61 | |
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| 62 | static void debug_logit( |
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| 63 | char act, |
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| 64 | SMP_lock_spinlock_nested_Control *lock |
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| 65 | ); |
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| 66 | static void debug_dump_log(void); |
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| 67 | #else |
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| 68 | #define debug_logit( _act, _lock ) |
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| 69 | #define debug_dump_log() |
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| 70 | #endif |
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| 71 | |
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| 72 | /* |
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| 73 | * SMP spinlock simple methods |
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| 74 | */ |
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[a8d7e2ab] | 75 | void _SMP_lock_spinlock_simple_Initialize( |
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| 76 | SMP_lock_spinlock_simple_Control *lock |
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[06dcaf0] | 77 | ) |
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| 78 | { |
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| 79 | *lock = 0; |
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| 80 | } |
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| 81 | |
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[a8d7e2ab] | 82 | ISR_Level _SMP_lock_spinlock_simple_Obtain( |
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| 83 | SMP_lock_spinlock_simple_Control *lock |
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| 84 | ) |
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| 85 | { |
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[dad36c52] | 86 | ISR_Level level = 0; |
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[a8d7e2ab] | 87 | uint32_t value = 1; |
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| 88 | uint32_t previous; |
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[dacdda30] | 89 | |
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[a8d7e2ab] | 90 | /* Note: Disable provides an implicit memory barrier. */ |
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[dad36c52] | 91 | _ISR_Disable_on_this_core( level ); |
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[a8d7e2ab] | 92 | do { |
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[dad36c52] | 93 | RTEMS_COMPILER_MEMORY_BARRIER(); |
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[a8d7e2ab] | 94 | SMP_CPU_SWAP( lock, value, previous ); |
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[dad36c52] | 95 | RTEMS_COMPILER_MEMORY_BARRIER(); |
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[a8d7e2ab] | 96 | } while (previous == 1); |
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| 97 | |
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| 98 | return level; |
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| 99 | } |
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| 100 | |
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| 101 | void _SMP_lock_spinlock_simple_Release( |
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| 102 | SMP_lock_spinlock_simple_Control *lock, |
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| 103 | ISR_Level level |
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| 104 | ) |
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| 105 | { |
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| 106 | *lock = 0; |
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[dad36c52] | 107 | _ISR_Enable_on_this_core( level ); |
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[a8d7e2ab] | 108 | } |
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| 109 | |
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[dad36c52] | 110 | /* |
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| 111 | * SMP spinlock nested methods. |
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| 112 | */ |
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[a8d7e2ab] | 113 | void _SMP_lock_spinlock_nested_Initialize( |
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| 114 | SMP_lock_spinlock_nested_Control *lock |
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| 115 | ) |
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| 116 | { |
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[35453000] | 117 | lock->lock = 0; |
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[a8d7e2ab] | 118 | lock->count = 0; |
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[dad36c52] | 119 | lock->cpu_id = -1; |
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| 120 | } |
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| 121 | |
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| 122 | void _SMP_lock_spinlock_nested_Release( |
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| 123 | SMP_lock_spinlock_nested_Control *lock, |
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| 124 | ISR_Level level |
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| 125 | ) |
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| 126 | { |
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| 127 | #if defined (RTEMS_DEBUG) || defined(SMPLOCK_DEBUG) |
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| 128 | if ( lock->count == 0 ) { |
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| 129 | printk( |
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| 130 | "\ncpu %d lock %d Releasing spinlock when count is already " |
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| 131 | "zero (%p from %p,%p)?!?!\n", |
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| 132 | bsp_smp_processor_id(), |
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| 133 | lock->cpu_id, |
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| 134 | lock, |
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| 135 | __builtin_return_address(0), |
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| 136 | __builtin_return_address(1) |
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| 137 | ); |
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| 138 | debug_dump_log(); |
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| 139 | return; |
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| 140 | } |
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| 141 | #endif |
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| 142 | |
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| 143 | /* assume we actually have it */ |
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| 144 | if (lock->count == 1) { |
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| 145 | lock->cpu_id = -1; |
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| 146 | debug_logit( 'U', lock ); |
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| 147 | lock->count = 0; |
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[35453000] | 148 | RTEMS_COMPILER_MEMORY_BARRIER(); |
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| 149 | lock->lock = 0; |
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[dad36c52] | 150 | } else { |
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| 151 | debug_logit( 'u', lock ); |
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| 152 | lock->count--; |
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| 153 | } |
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| 154 | |
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| 155 | _ISR_Enable_on_this_core( level ); |
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[a8d7e2ab] | 156 | } |
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| 157 | |
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| 158 | ISR_Level _SMP_lock_spinlock_nested_Obtain( |
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| 159 | SMP_lock_spinlock_nested_Control *lock |
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[06dcaf0] | 160 | ) |
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| 161 | { |
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[a8d7e2ab] | 162 | ISR_Level level = 0; |
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[06dcaf0] | 163 | uint32_t value = 1; |
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| 164 | uint32_t previous; |
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[a8d7e2ab] | 165 | int cpu_id; |
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[06dcaf0] | 166 | |
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| 167 | /* Note: Disable provides an implicit memory barrier. */ |
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[dad36c52] | 168 | _ISR_Disable_on_this_core( level ); |
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[a8d7e2ab] | 169 | |
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| 170 | cpu_id = bsp_smp_processor_id(); |
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| 171 | |
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[dad36c52] | 172 | /* |
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| 173 | * Attempt to obtain the lock. If we do not get it immediately, then |
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| 174 | * do a single "monitor" iteration. This should allow the loop to back |
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| 175 | * off the bus a bit and allow the other core to finish sooner. |
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| 176 | */ |
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| 177 | while (1) { |
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| 178 | RTEMS_COMPILER_MEMORY_BARRIER(); |
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[35453000] | 179 | SMP_CPU_SWAP( &lock->lock, value, previous ); |
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[dad36c52] | 180 | RTEMS_COMPILER_MEMORY_BARRIER(); |
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| 181 | if ( previous == 0 ) { |
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| 182 | /* was not locked */ |
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| 183 | break; |
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| 184 | } |
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[dacdda30] | 185 | |
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[dad36c52] | 186 | /* Deal with nested calls from one cpu */ |
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| 187 | if (cpu_id == lock->cpu_id) { |
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| 188 | lock->count++; |
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| 189 | debug_logit( 'l', lock ); |
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| 190 | return level; |
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| 191 | } |
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| 192 | } |
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[a8d7e2ab] | 193 | |
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| 194 | lock->cpu_id = cpu_id; |
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[35453000] | 195 | lock->count = 1; |
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[dad36c52] | 196 | debug_logit( 'L', lock ); |
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[a8d7e2ab] | 197 | |
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[06dcaf0] | 198 | return level; |
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| 199 | } |
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| 200 | |
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[dad36c52] | 201 | /* |
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| 202 | * Debug log for debugging nested lock/unlock problems. |
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| 203 | */ |
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| 204 | #if defined(ENABLE_DEBUG_LOGGING) |
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| 205 | static void debug_logit( |
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| 206 | char act, |
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| 207 | SMP_lock_spinlock_nested_Control *lock |
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| 208 | ) |
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| 209 | { |
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| 210 | debug_debug_spinlog_t *sp; |
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| 211 | if ( DEBUG_SPINLOG_INDEX == DEBUG_SPINLOG_MAX ) |
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| 212 | #if defined (ENABLE_LOOPED_DEBUG_LOGGING) |
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| 213 | DEBUG_SPINLOG_INDEX = 0; |
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| 214 | #else |
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| 215 | return; |
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| 216 | #endif |
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[dacdda30] | 217 | |
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[dad36c52] | 218 | sp = &DEBUG_SPINLOG[ DEBUG_SPINLOG_INDEX++ ]; |
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| 219 | sp->action = act; |
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| 220 | |
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| 221 | #if 0 |
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| 222 | if ( lock == &_ISR_SMP_Lock ) |
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| 223 | sp->lock = 'I'; |
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| 224 | else |
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| 225 | #endif |
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| 226 | if ( lock == &_Thread_Dispatch_disable_level_lock ) |
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| 227 | sp->lock = 'D'; |
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| 228 | sp->cpu = bsp_smp_processor_id() + '0'; |
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| 229 | sp->count = lock->count; |
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| 230 | #if 0 |
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| 231 | if ( sp->lock == 'I' ) { |
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| 232 | if ( _Thread_Dispatch_smp_spin_lock.id == 0 ) |
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| 233 | printk( "not nested %p from %p %p %p %p\n", sp, |
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| 234 | __builtin_return_address(0), __builtin_return_address(1), |
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| 235 | __builtin_return_address(2), __builtin_return_address(3) |
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| 236 | ); |
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| 237 | } |
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| 238 | #endif |
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| 239 | sp->nest_level = _ISR_Nest_level; |
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| 240 | sp->ret1 = 0; |
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| 241 | sp->ret2 = 0; |
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| 242 | sp->ret3 = 0; |
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| 243 | sp->ret4 = 0; |
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| 244 | sp->ret1 = __builtin_return_address(0); |
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| 245 | if ( sp->ret1 >= start && sp->ret1 <= _fini ) { |
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| 246 | sp->ret2 = __builtin_return_address(1); |
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| 247 | if ( sp->ret2 >= start && sp->ret2 <= _fini ) { |
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| 248 | sp->ret3 = __builtin_return_address(2); |
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| 249 | if ( sp->ret3 >= start && sp->ret3 <= _fini ) { |
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| 250 | sp->ret4 = __builtin_return_address(3); |
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| 251 | } |
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| 252 | } |
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| 253 | } |
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| 254 | } |
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| 255 | |
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| 256 | static void debug_dump_log(void) |
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| 257 | { |
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| 258 | debug_debug_spinlog_t *sp; |
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| 259 | int index; |
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| 260 | bool done =false; |
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| 261 | |
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| 262 | #if defined (ENABLE_ONESHOT_DEBUG_LOGGING) |
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| 263 | index = 0; |
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| 264 | #else |
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| 265 | if (DEBUG_SPINLOG_INDEX >= DEBUG_SPINLOG_MAX) |
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| 266 | index = 0; |
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| 267 | else |
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| 268 | index = DEBUG_SPINLOG_INDEX; |
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| 269 | #endif |
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| 270 | |
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| 271 | |
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| 272 | do { |
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| 273 | sp = &DEBUG_SPINLOG[ index ]; |
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| 274 | printk("%d) act %c lock %c cpu %c count=%d nest %d (%p, %p, %p, %p)\n", |
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| 275 | index, sp->action, sp->lock, sp->cpu, sp->count, sp->nest_level, |
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| 276 | sp->ret1, sp->ret2, sp->ret3, sp->ret4 |
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| 277 | ); |
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| 278 | |
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| 279 | index++; |
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| 280 | if (index == DEBUG_SPINLOG_INDEX) |
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| 281 | break; |
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| 282 | if (index >= DEBUG_SPINLOG_MAX) |
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| 283 | index = 0; |
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| 284 | } while (1); |
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| 285 | } |
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| 286 | #endif |
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