Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame^] | 1 | #include <linux/init.h> |
| 2 | |
| 3 | #include <linux/mm.h> |
| 4 | #include <linux/delay.h> |
| 5 | #include <linux/spinlock.h> |
| 6 | #include <linux/kernel_stat.h> |
| 7 | #include <linux/mc146818rtc.h> |
| 8 | #include <linux/cache.h> |
| 9 | #include <linux/interrupt.h> |
| 10 | #include <linux/cpu.h> |
| 11 | |
| 12 | #include <asm/mtrr.h> |
| 13 | #include <asm/tlbflush.h> |
| 14 | #include <asm/mmu_context.h> |
| 15 | #include <asm/proto.h> |
| 16 | #ifdef CONFIG_X86_32 |
| 17 | #include <mach_apic.h> |
| 18 | #include <mach_ipi.h> |
| 19 | #else |
| 20 | #include <asm/mach_apic.h> |
| 21 | #endif |
| 22 | |
| 23 | /* |
| 24 | * this function sends a 'reschedule' IPI to another CPU. |
| 25 | * it goes straight through and wastes no time serializing |
| 26 | * anything. Worst case is that we lose a reschedule ... |
| 27 | */ |
| 28 | static void native_smp_send_reschedule(int cpu) |
| 29 | { |
| 30 | WARN_ON(cpu_is_offline(cpu)); |
| 31 | send_IPI_mask(cpumask_of_cpu(cpu), RESCHEDULE_VECTOR); |
| 32 | } |
| 33 | |
| 34 | /* |
| 35 | * Structure and data for smp_call_function(). This is designed to minimise |
| 36 | * static memory requirements. It also looks cleaner. |
| 37 | */ |
| 38 | static DEFINE_SPINLOCK(call_lock); |
| 39 | |
| 40 | struct call_data_struct { |
| 41 | void (*func) (void *info); |
| 42 | void *info; |
| 43 | atomic_t started; |
| 44 | atomic_t finished; |
| 45 | int wait; |
| 46 | }; |
| 47 | |
| 48 | void lock_ipi_call_lock(void) |
| 49 | { |
| 50 | spin_lock_irq(&call_lock); |
| 51 | } |
| 52 | |
| 53 | void unlock_ipi_call_lock(void) |
| 54 | { |
| 55 | spin_unlock_irq(&call_lock); |
| 56 | } |
| 57 | |
| 58 | static struct call_data_struct *call_data; |
| 59 | |
| 60 | static void __smp_call_function(void (*func) (void *info), void *info, |
| 61 | int nonatomic, int wait) |
| 62 | { |
| 63 | struct call_data_struct data; |
| 64 | int cpus = num_online_cpus() - 1; |
| 65 | |
| 66 | if (!cpus) |
| 67 | return; |
| 68 | |
| 69 | data.func = func; |
| 70 | data.info = info; |
| 71 | atomic_set(&data.started, 0); |
| 72 | data.wait = wait; |
| 73 | if (wait) |
| 74 | atomic_set(&data.finished, 0); |
| 75 | |
| 76 | call_data = &data; |
| 77 | mb(); |
| 78 | |
| 79 | /* Send a message to all other CPUs and wait for them to respond */ |
| 80 | send_IPI_allbutself(CALL_FUNCTION_VECTOR); |
| 81 | |
| 82 | /* Wait for response */ |
| 83 | while (atomic_read(&data.started) != cpus) |
| 84 | cpu_relax(); |
| 85 | |
| 86 | if (wait) |
| 87 | while (atomic_read(&data.finished) != cpus) |
| 88 | cpu_relax(); |
| 89 | } |
| 90 | |
| 91 | |
| 92 | /** |
| 93 | * smp_call_function_mask(): Run a function on a set of other CPUs. |
| 94 | * @mask: The set of cpus to run on. Must not include the current cpu. |
| 95 | * @func: The function to run. This must be fast and non-blocking. |
| 96 | * @info: An arbitrary pointer to pass to the function. |
| 97 | * @wait: If true, wait (atomically) until function has completed on other CPUs. |
| 98 | * |
| 99 | * Returns 0 on success, else a negative status code. |
| 100 | * |
| 101 | * If @wait is true, then returns once @func has returned; otherwise |
| 102 | * it returns just before the target cpu calls @func. |
| 103 | * |
| 104 | * You must not call this function with disabled interrupts or from a |
| 105 | * hardware interrupt handler or from a bottom half handler. |
| 106 | */ |
| 107 | static int |
| 108 | native_smp_call_function_mask(cpumask_t mask, |
| 109 | void (*func)(void *), void *info, |
| 110 | int wait) |
| 111 | { |
| 112 | struct call_data_struct data; |
| 113 | cpumask_t allbutself; |
| 114 | int cpus; |
| 115 | |
| 116 | /* Can deadlock when called with interrupts disabled */ |
| 117 | WARN_ON(irqs_disabled()); |
| 118 | |
| 119 | /* Holding any lock stops cpus from going down. */ |
| 120 | spin_lock(&call_lock); |
| 121 | |
| 122 | allbutself = cpu_online_map; |
| 123 | cpu_clear(smp_processor_id(), allbutself); |
| 124 | |
| 125 | cpus_and(mask, mask, allbutself); |
| 126 | cpus = cpus_weight(mask); |
| 127 | |
| 128 | if (!cpus) { |
| 129 | spin_unlock(&call_lock); |
| 130 | return 0; |
| 131 | } |
| 132 | |
| 133 | data.func = func; |
| 134 | data.info = info; |
| 135 | atomic_set(&data.started, 0); |
| 136 | data.wait = wait; |
| 137 | if (wait) |
| 138 | atomic_set(&data.finished, 0); |
| 139 | |
| 140 | call_data = &data; |
| 141 | wmb(); |
| 142 | |
| 143 | /* Send a message to other CPUs */ |
| 144 | if (cpus_equal(mask, allbutself)) |
| 145 | send_IPI_allbutself(CALL_FUNCTION_VECTOR); |
| 146 | else |
| 147 | send_IPI_mask(mask, CALL_FUNCTION_VECTOR); |
| 148 | |
| 149 | /* Wait for response */ |
| 150 | while (atomic_read(&data.started) != cpus) |
| 151 | cpu_relax(); |
| 152 | |
| 153 | if (wait) |
| 154 | while (atomic_read(&data.finished) != cpus) |
| 155 | cpu_relax(); |
| 156 | spin_unlock(&call_lock); |
| 157 | |
| 158 | return 0; |
| 159 | } |
| 160 | |
| 161 | static void stop_this_cpu(void *dummy) |
| 162 | { |
| 163 | local_irq_disable(); |
| 164 | /* |
| 165 | * Remove this CPU: |
| 166 | */ |
| 167 | cpu_clear(smp_processor_id(), cpu_online_map); |
| 168 | disable_local_APIC(); |
| 169 | if (hlt_works(smp_processor_id())) |
| 170 | for (;;) halt(); |
| 171 | for (;;); |
| 172 | } |
| 173 | |
| 174 | /* |
| 175 | * this function calls the 'stop' function on all other CPUs in the system. |
| 176 | */ |
| 177 | |
| 178 | static void native_smp_send_stop(void) |
| 179 | { |
| 180 | int nolock; |
| 181 | unsigned long flags; |
| 182 | |
| 183 | if (reboot_force) |
| 184 | return; |
| 185 | |
| 186 | /* Don't deadlock on the call lock in panic */ |
| 187 | nolock = !spin_trylock(&call_lock); |
| 188 | local_irq_save(flags); |
| 189 | __smp_call_function(stop_this_cpu, NULL, 0, 0); |
| 190 | if (!nolock) |
| 191 | spin_unlock(&call_lock); |
| 192 | disable_local_APIC(); |
| 193 | local_irq_restore(flags); |
| 194 | } |
| 195 | |
| 196 | /* |
| 197 | * Reschedule call back. Nothing to do, |
| 198 | * all the work is done automatically when |
| 199 | * we return from the interrupt. |
| 200 | */ |
| 201 | void smp_reschedule_interrupt(struct pt_regs *regs) |
| 202 | { |
| 203 | ack_APIC_irq(); |
| 204 | #ifdef CONFIG_X86_32 |
| 205 | __get_cpu_var(irq_stat).irq_resched_count++; |
| 206 | #else |
| 207 | add_pda(irq_resched_count, 1); |
| 208 | #endif |
| 209 | } |
| 210 | |
| 211 | void smp_call_function_interrupt(struct pt_regs *regs) |
| 212 | { |
| 213 | void (*func) (void *info) = call_data->func; |
| 214 | void *info = call_data->info; |
| 215 | int wait = call_data->wait; |
| 216 | |
| 217 | ack_APIC_irq(); |
| 218 | /* |
| 219 | * Notify initiating CPU that I've grabbed the data and am |
| 220 | * about to execute the function |
| 221 | */ |
| 222 | mb(); |
| 223 | atomic_inc(&call_data->started); |
| 224 | /* |
| 225 | * At this point the info structure may be out of scope unless wait==1 |
| 226 | */ |
| 227 | irq_enter(); |
| 228 | (*func)(info); |
| 229 | #ifdef CONFIG_X86_32 |
| 230 | __get_cpu_var(irq_stat).irq_call_count++; |
| 231 | #else |
| 232 | add_pda(irq_call_count, 1); |
| 233 | #endif |
| 234 | irq_exit(); |
| 235 | |
| 236 | if (wait) { |
| 237 | mb(); |
| 238 | atomic_inc(&call_data->finished); |
| 239 | } |
| 240 | } |
| 241 | |
| 242 | struct smp_ops smp_ops = { |
| 243 | .smp_prepare_boot_cpu = native_smp_prepare_boot_cpu, |
| 244 | .smp_prepare_cpus = native_smp_prepare_cpus, |
| 245 | .cpu_up = native_cpu_up, |
| 246 | .smp_cpus_done = native_smp_cpus_done, |
| 247 | |
| 248 | .smp_send_stop = native_smp_send_stop, |
| 249 | .smp_send_reschedule = native_smp_send_reschedule, |
| 250 | .smp_call_function_mask = native_smp_call_function_mask, |
| 251 | }; |
| 252 | EXPORT_SYMBOL_GPL(smp_ops); |
| 253 | |