Glauber Costa | 0941ecb | 2008-03-03 14:12:55 -0300 | [diff] [blame] | 1 | /* |
| 2 | * Intel SMP support routines. |
| 3 | * |
Alan Cox | 87c6fe2 | 2009-01-05 14:08:04 +0000 | [diff] [blame] | 4 | * (c) 1995 Alan Cox, Building #3 <alan@lxorguk.ukuu.org.uk> |
Ingo Molnar | 8f47e16 | 2009-01-31 02:03:42 +0100 | [diff] [blame] | 5 | * (c) 1998-99, 2000, 2009 Ingo Molnar <mingo@redhat.com> |
Glauber Costa | 0941ecb | 2008-03-03 14:12:55 -0300 | [diff] [blame] | 6 | * (c) 2002,2003 Andi Kleen, SuSE Labs. |
| 7 | * |
| 8 | * i386 and x86_64 integration by Glauber Costa <gcosta@redhat.com> |
| 9 | * |
| 10 | * This code is released under the GNU General Public License version 2 or |
| 11 | * later. |
| 12 | */ |
| 13 | |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 14 | #include <linux/init.h> |
| 15 | |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/delay.h> |
| 18 | #include <linux/spinlock.h> |
Paul Gortmaker | 69c60c8 | 2011-05-26 12:22:53 -0400 | [diff] [blame] | 19 | #include <linux/export.h> |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 20 | #include <linux/kernel_stat.h> |
| 21 | #include <linux/mc146818rtc.h> |
| 22 | #include <linux/cache.h> |
| 23 | #include <linux/interrupt.h> |
| 24 | #include <linux/cpu.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 25 | #include <linux/gfp.h> |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 26 | |
| 27 | #include <asm/mtrr.h> |
| 28 | #include <asm/tlbflush.h> |
| 29 | #include <asm/mmu_context.h> |
| 30 | #include <asm/proto.h> |
Ingo Molnar | 7b6aa33 | 2009-02-17 13:58:15 +0100 | [diff] [blame] | 31 | #include <asm/apic.h> |
Don Zickus | 3603a25 | 2011-10-13 15:14:25 -0400 | [diff] [blame] | 32 | #include <asm/nmi.h> |
Glauber Costa | 0941ecb | 2008-03-03 14:12:55 -0300 | [diff] [blame] | 33 | /* |
| 34 | * Some notes on x86 processor bugs affecting SMP operation: |
| 35 | * |
| 36 | * Pentium, Pentium Pro, II, III (and all CPUs) have bugs. |
| 37 | * The Linux implications for SMP are handled as follows: |
| 38 | * |
| 39 | * Pentium III / [Xeon] |
| 40 | * None of the E1AP-E3AP errata are visible to the user. |
| 41 | * |
| 42 | * E1AP. see PII A1AP |
| 43 | * E2AP. see PII A2AP |
| 44 | * E3AP. see PII A3AP |
| 45 | * |
| 46 | * Pentium II / [Xeon] |
| 47 | * None of the A1AP-A3AP errata are visible to the user. |
| 48 | * |
| 49 | * A1AP. see PPro 1AP |
| 50 | * A2AP. see PPro 2AP |
| 51 | * A3AP. see PPro 7AP |
| 52 | * |
| 53 | * Pentium Pro |
| 54 | * None of 1AP-9AP errata are visible to the normal user, |
| 55 | * except occasional delivery of 'spurious interrupt' as trap #15. |
| 56 | * This is very rare and a non-problem. |
| 57 | * |
| 58 | * 1AP. Linux maps APIC as non-cacheable |
| 59 | * 2AP. worked around in hardware |
| 60 | * 3AP. fixed in C0 and above steppings microcode update. |
| 61 | * Linux does not use excessive STARTUP_IPIs. |
| 62 | * 4AP. worked around in hardware |
| 63 | * 5AP. symmetric IO mode (normal Linux operation) not affected. |
| 64 | * 'noapic' mode has vector 0xf filled out properly. |
| 65 | * 6AP. 'noapic' mode might be affected - fixed in later steppings |
| 66 | * 7AP. We do not assume writes to the LVT deassering IRQs |
| 67 | * 8AP. We do not enable low power mode (deep sleep) during MP bootup |
| 68 | * 9AP. We do not use mixed mode |
| 69 | * |
| 70 | * Pentium |
| 71 | * There is a marginal case where REP MOVS on 100MHz SMP |
| 72 | * machines with B stepping processors can fail. XXX should provide |
| 73 | * an L1cache=Writethrough or L1cache=off option. |
| 74 | * |
| 75 | * B stepping CPUs may hang. There are hardware work arounds |
| 76 | * for this. We warn about it in case your board doesn't have the work |
| 77 | * arounds. Basically that's so I can tell anyone with a B stepping |
| 78 | * CPU and SMP problems "tough". |
| 79 | * |
| 80 | * Specific items [From Pentium Processor Specification Update] |
| 81 | * |
| 82 | * 1AP. Linux doesn't use remote read |
| 83 | * 2AP. Linux doesn't trust APIC errors |
| 84 | * 3AP. We work around this |
| 85 | * 4AP. Linux never generated 3 interrupts of the same priority |
| 86 | * to cause a lost local interrupt. |
| 87 | * 5AP. Remote read is never used |
| 88 | * 6AP. not affected - worked around in hardware |
| 89 | * 7AP. not affected - worked around in hardware |
| 90 | * 8AP. worked around in hardware - we get explicit CS errors if not |
| 91 | * 9AP. only 'noapic' mode affected. Might generate spurious |
| 92 | * interrupts, we log only the first one and count the |
| 93 | * rest silently. |
| 94 | * 10AP. not affected - worked around in hardware |
| 95 | * 11AP. Linux reads the APIC between writes to avoid this, as per |
| 96 | * the documentation. Make sure you preserve this as it affects |
| 97 | * the C stepping chips too. |
| 98 | * 12AP. not affected - worked around in hardware |
| 99 | * 13AP. not affected - worked around in hardware |
| 100 | * 14AP. we always deassert INIT during bootup |
| 101 | * 15AP. not affected - worked around in hardware |
| 102 | * 16AP. not affected - worked around in hardware |
| 103 | * 17AP. not affected - worked around in hardware |
| 104 | * 18AP. not affected - worked around in hardware |
| 105 | * 19AP. not affected - worked around in BIOS |
| 106 | * |
| 107 | * If this sounds worrying believe me these bugs are either ___RARE___, |
| 108 | * or are signal timing bugs worked around in hardware and there's |
| 109 | * about nothing of note with C stepping upwards. |
| 110 | */ |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 111 | |
| 112 | /* |
| 113 | * this function sends a 'reschedule' IPI to another CPU. |
| 114 | * it goes straight through and wastes no time serializing |
| 115 | * anything. Worst case is that we lose a reschedule ... |
| 116 | */ |
| 117 | static void native_smp_send_reschedule(int cpu) |
| 118 | { |
Gautham R Shenoy | f694010 | 2008-03-10 17:44:03 +0530 | [diff] [blame] | 119 | if (unlikely(cpu_is_offline(cpu))) { |
| 120 | WARN_ON(1); |
| 121 | return; |
| 122 | } |
Ingo Molnar | dac5f41 | 2009-01-28 15:42:24 +0100 | [diff] [blame] | 123 | apic->send_IPI_mask(cpumask_of(cpu), RESCHEDULE_VECTOR); |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 124 | } |
| 125 | |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 126 | void native_send_call_func_single_ipi(int cpu) |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 127 | { |
Ingo Molnar | dac5f41 | 2009-01-28 15:42:24 +0100 | [diff] [blame] | 128 | apic->send_IPI_mask(cpumask_of(cpu), CALL_FUNCTION_SINGLE_VECTOR); |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 129 | } |
| 130 | |
Mike Travis | bcda016 | 2008-12-16 17:33:59 -0800 | [diff] [blame] | 131 | void native_send_call_func_ipi(const struct cpumask *mask) |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 132 | { |
Mike Travis | c2d1cec | 2009-01-04 05:18:03 -0800 | [diff] [blame] | 133 | cpumask_var_t allbutself; |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 134 | |
Mike Travis | c2d1cec | 2009-01-04 05:18:03 -0800 | [diff] [blame] | 135 | if (!alloc_cpumask_var(&allbutself, GFP_ATOMIC)) { |
Ingo Molnar | dac5f41 | 2009-01-28 15:42:24 +0100 | [diff] [blame] | 136 | apic->send_IPI_mask(mask, CALL_FUNCTION_VECTOR); |
Mike Travis | c2d1cec | 2009-01-04 05:18:03 -0800 | [diff] [blame] | 137 | return; |
| 138 | } |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 139 | |
Mike Travis | c2d1cec | 2009-01-04 05:18:03 -0800 | [diff] [blame] | 140 | cpumask_copy(allbutself, cpu_online_mask); |
| 141 | cpumask_clear_cpu(smp_processor_id(), allbutself); |
| 142 | |
| 143 | if (cpumask_equal(mask, allbutself) && |
| 144 | cpumask_equal(cpu_online_mask, cpu_callout_mask)) |
Ingo Molnar | dac5f41 | 2009-01-28 15:42:24 +0100 | [diff] [blame] | 145 | apic->send_IPI_allbutself(CALL_FUNCTION_VECTOR); |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 146 | else |
Ingo Molnar | dac5f41 | 2009-01-28 15:42:24 +0100 | [diff] [blame] | 147 | apic->send_IPI_mask(mask, CALL_FUNCTION_VECTOR); |
Mike Travis | c2d1cec | 2009-01-04 05:18:03 -0800 | [diff] [blame] | 148 | |
| 149 | free_cpumask_var(allbutself); |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 150 | } |
| 151 | |
Don Zickus | 3603a25 | 2011-10-13 15:14:25 -0400 | [diff] [blame] | 152 | static atomic_t stopping_cpu = ATOMIC_INIT(-1); |
| 153 | |
| 154 | static int smp_stop_nmi_callback(unsigned int val, struct pt_regs *regs) |
| 155 | { |
| 156 | /* We are registered on stopping cpu too, avoid spurious NMI */ |
| 157 | if (raw_smp_processor_id() == atomic_read(&stopping_cpu)) |
| 158 | return NMI_HANDLED; |
| 159 | |
| 160 | stop_this_cpu(NULL); |
| 161 | |
| 162 | return NMI_HANDLED; |
| 163 | } |
| 164 | |
| 165 | static void native_nmi_stop_other_cpus(int wait) |
| 166 | { |
| 167 | unsigned long flags; |
| 168 | unsigned long timeout; |
| 169 | |
| 170 | if (reboot_force) |
| 171 | return; |
| 172 | |
| 173 | /* |
| 174 | * Use an own vector here because smp_call_function |
| 175 | * does lots of things not suitable in a panic situation. |
| 176 | */ |
| 177 | if (num_online_cpus() > 1) { |
| 178 | /* did someone beat us here? */ |
Don Zickus | e58d429 | 2012-01-06 11:17:51 -0500 | [diff] [blame] | 179 | if (atomic_cmpxchg(&stopping_cpu, -1, safe_smp_processor_id()) != -1) |
Don Zickus | 3603a25 | 2011-10-13 15:14:25 -0400 | [diff] [blame] | 180 | return; |
| 181 | |
| 182 | if (register_nmi_handler(NMI_LOCAL, smp_stop_nmi_callback, |
| 183 | NMI_FLAG_FIRST, "smp_stop")) |
| 184 | /* Note: we ignore failures here */ |
| 185 | return; |
| 186 | |
| 187 | /* sync above data before sending NMI */ |
| 188 | wmb(); |
| 189 | |
| 190 | apic->send_IPI_allbutself(NMI_VECTOR); |
| 191 | |
| 192 | /* |
| 193 | * Don't wait longer than a second if the caller |
| 194 | * didn't ask us to wait. |
| 195 | */ |
| 196 | timeout = USEC_PER_SEC; |
| 197 | while (num_online_cpus() > 1 && (wait || timeout--)) |
| 198 | udelay(1); |
| 199 | } |
| 200 | |
| 201 | local_irq_save(flags); |
| 202 | disable_local_APIC(); |
| 203 | local_irq_restore(flags); |
| 204 | } |
| 205 | |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 206 | /* |
| 207 | * this function calls the 'stop' function on all other CPUs in the system. |
| 208 | */ |
| 209 | |
Andi Kleen | 4ef702c | 2009-05-27 21:56:52 +0200 | [diff] [blame] | 210 | asmlinkage void smp_reboot_interrupt(void) |
| 211 | { |
| 212 | ack_APIC_irq(); |
| 213 | irq_enter(); |
| 214 | stop_this_cpu(NULL); |
| 215 | irq_exit(); |
| 216 | } |
| 217 | |
Don Zickus | 3603a25 | 2011-10-13 15:14:25 -0400 | [diff] [blame] | 218 | static void native_irq_stop_other_cpus(int wait) |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 219 | { |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 220 | unsigned long flags; |
Alok Kataria | 76fac07 | 2010-10-11 14:37:08 -0700 | [diff] [blame] | 221 | unsigned long timeout; |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 222 | |
| 223 | if (reboot_force) |
| 224 | return; |
| 225 | |
Andi Kleen | 4ef702c | 2009-05-27 21:56:52 +0200 | [diff] [blame] | 226 | /* |
| 227 | * Use an own vector here because smp_call_function |
| 228 | * does lots of things not suitable in a panic situation. |
| 229 | * On most systems we could also use an NMI here, |
| 230 | * but there are a few systems around where NMI |
| 231 | * is problematic so stay with an non NMI for now |
| 232 | * (this implies we cannot stop CPUs spinning with irq off |
| 233 | * currently) |
| 234 | */ |
| 235 | if (num_online_cpus() > 1) { |
| 236 | apic->send_IPI_allbutself(REBOOT_VECTOR); |
| 237 | |
Alok Kataria | 76fac07 | 2010-10-11 14:37:08 -0700 | [diff] [blame] | 238 | /* |
| 239 | * Don't wait longer than a second if the caller |
| 240 | * didn't ask us to wait. |
| 241 | */ |
| 242 | timeout = USEC_PER_SEC; |
| 243 | while (num_online_cpus() > 1 && (wait || timeout--)) |
Andi Kleen | 4ef702c | 2009-05-27 21:56:52 +0200 | [diff] [blame] | 244 | udelay(1); |
| 245 | } |
| 246 | |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 247 | local_irq_save(flags); |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 248 | disable_local_APIC(); |
| 249 | local_irq_restore(flags); |
| 250 | } |
| 251 | |
Don Zickus | bda6263 | 2011-10-13 15:14:27 -0400 | [diff] [blame] | 252 | static void native_smp_disable_nmi_ipi(void) |
| 253 | { |
| 254 | smp_ops.stop_other_cpus = native_irq_stop_other_cpus; |
| 255 | } |
| 256 | |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 257 | /* |
Peter Zijlstra | 184748c | 2011-04-05 17:23:39 +0200 | [diff] [blame] | 258 | * Reschedule call back. |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 259 | */ |
| 260 | void smp_reschedule_interrupt(struct pt_regs *regs) |
| 261 | { |
| 262 | ack_APIC_irq(); |
Hiroshi Shimamoto | 915b0d0 | 2008-12-08 19:19:26 -0800 | [diff] [blame] | 263 | inc_irq_stat(irq_resched_count); |
Peter Zijlstra | 184748c | 2011-04-05 17:23:39 +0200 | [diff] [blame] | 264 | scheduler_ipi(); |
Marcelo Tosatti | 32f8840 | 2009-05-07 17:55:12 -0300 | [diff] [blame] | 265 | /* |
| 266 | * KVM uses this interrupt to force a cpu out of guest mode |
| 267 | */ |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 268 | } |
| 269 | |
| 270 | void smp_call_function_interrupt(struct pt_regs *regs) |
| 271 | { |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 272 | ack_APIC_irq(); |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 273 | irq_enter(); |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 274 | generic_smp_call_function_interrupt(); |
Hiroshi Shimamoto | 915b0d0 | 2008-12-08 19:19:26 -0800 | [diff] [blame] | 275 | inc_irq_stat(irq_call_count); |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 276 | irq_exit(); |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 277 | } |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 278 | |
Jens Axboe | 5e374fb | 2008-07-01 13:12:04 +0200 | [diff] [blame] | 279 | void smp_call_function_single_interrupt(struct pt_regs *regs) |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 280 | { |
| 281 | ack_APIC_irq(); |
| 282 | irq_enter(); |
| 283 | generic_smp_call_function_single_interrupt(); |
Hiroshi Shimamoto | 915b0d0 | 2008-12-08 19:19:26 -0800 | [diff] [blame] | 284 | inc_irq_stat(irq_call_count); |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 285 | irq_exit(); |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 286 | } |
| 287 | |
Don Zickus | bda6263 | 2011-10-13 15:14:27 -0400 | [diff] [blame] | 288 | static int __init nonmi_ipi_setup(char *str) |
| 289 | { |
| 290 | native_smp_disable_nmi_ipi(); |
| 291 | return 1; |
| 292 | } |
| 293 | |
| 294 | __setup("nonmi_ipi", nonmi_ipi_setup); |
| 295 | |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 296 | struct smp_ops smp_ops = { |
Cyrill Gorcunov | b9b34f2 | 2009-04-12 20:47:42 +0400 | [diff] [blame] | 297 | .smp_prepare_boot_cpu = native_smp_prepare_boot_cpu, |
| 298 | .smp_prepare_cpus = native_smp_prepare_cpus, |
| 299 | .smp_cpus_done = native_smp_cpus_done, |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 300 | |
Don Zickus | 3603a25 | 2011-10-13 15:14:25 -0400 | [diff] [blame] | 301 | .stop_other_cpus = native_nmi_stop_other_cpus, |
Cyrill Gorcunov | b9b34f2 | 2009-04-12 20:47:42 +0400 | [diff] [blame] | 302 | .smp_send_reschedule = native_smp_send_reschedule, |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 303 | |
Cyrill Gorcunov | b9b34f2 | 2009-04-12 20:47:42 +0400 | [diff] [blame] | 304 | .cpu_up = native_cpu_up, |
| 305 | .cpu_die = native_cpu_die, |
| 306 | .cpu_disable = native_cpu_disable, |
| 307 | .play_dead = native_play_dead, |
Alex Nixon | 93be71b | 2008-08-22 11:52:11 +0100 | [diff] [blame] | 308 | |
Cyrill Gorcunov | b9b34f2 | 2009-04-12 20:47:42 +0400 | [diff] [blame] | 309 | .send_call_func_ipi = native_send_call_func_ipi, |
Jens Axboe | 3b16cf8 | 2008-06-26 11:21:54 +0200 | [diff] [blame] | 310 | .send_call_func_single_ipi = native_send_call_func_single_ipi, |
Glauber Costa | f9e47a1 | 2008-03-03 14:12:52 -0300 | [diff] [blame] | 311 | }; |
| 312 | EXPORT_SYMBOL_GPL(smp_ops); |