~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/powerpc/platforms/powernv/smp.c

Version: ~ [ linux-5.12-rc1 ] ~ [ linux-5.11.2 ] ~ [ linux-5.10.19 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.101 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.177 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.222 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.258 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.258 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * SMP support for PowerNV machines.
  3  *
  4  * Copyright 2011 IBM Corp.
  5  *
  6  * This program is free software; you can redistribute it and/or
  7  * modify it under the terms of the GNU General Public License
  8  * as published by the Free Software Foundation; either version
  9  * 2 of the License, or (at your option) any later version.
 10  */
 11 
 12 #include <linux/kernel.h>
 13 #include <linux/module.h>
 14 #include <linux/sched.h>
 15 #include <linux/smp.h>
 16 #include <linux/interrupt.h>
 17 #include <linux/delay.h>
 18 #include <linux/init.h>
 19 #include <linux/spinlock.h>
 20 #include <linux/cpu.h>
 21 
 22 #include <asm/irq.h>
 23 #include <asm/smp.h>
 24 #include <asm/paca.h>
 25 #include <asm/machdep.h>
 26 #include <asm/cputable.h>
 27 #include <asm/firmware.h>
 28 #include <asm/vdso_datapage.h>
 29 #include <asm/cputhreads.h>
 30 #include <asm/xics.h>
 31 #include <asm/opal.h>
 32 #include <asm/runlatch.h>
 33 #include <asm/code-patching.h>
 34 #include <asm/dbell.h>
 35 #include <asm/kvm_ppc.h>
 36 #include <asm/ppc-opcode.h>
 37 
 38 #include "powernv.h"
 39 
 40 #ifdef DEBUG
 41 #include <asm/udbg.h>
 42 #define DBG(fmt...) udbg_printf(fmt)
 43 #else
 44 #define DBG(fmt...)
 45 #endif
 46 
 47 static void pnv_smp_setup_cpu(int cpu)
 48 {
 49         if (cpu != boot_cpuid)
 50                 xics_setup_cpu();
 51 
 52 #ifdef CONFIG_PPC_DOORBELL
 53         if (cpu_has_feature(CPU_FTR_DBELL))
 54                 doorbell_setup_this_cpu();
 55 #endif
 56 }
 57 
 58 static int pnv_smp_kick_cpu(int nr)
 59 {
 60         unsigned int pcpu = get_hard_smp_processor_id(nr);
 61         unsigned long start_here =
 62                         __pa(ppc_function_entry(generic_secondary_smp_init));
 63         long rc;
 64         uint8_t status;
 65 
 66         BUG_ON(nr < 0 || nr >= NR_CPUS);
 67 
 68         /*
 69          * If we already started or OPAL is not supported, we just
 70          * kick the CPU via the PACA
 71          */
 72         if (paca[nr].cpu_start || !firmware_has_feature(FW_FEATURE_OPAL))
 73                 goto kick;
 74 
 75         /*
 76          * At this point, the CPU can either be spinning on the way in
 77          * from kexec or be inside OPAL waiting to be started for the
 78          * first time. OPAL v3 allows us to query OPAL to know if it
 79          * has the CPUs, so we do that
 80          */
 81         rc = opal_query_cpu_status(pcpu, &status);
 82         if (rc != OPAL_SUCCESS) {
 83                 pr_warn("OPAL Error %ld querying CPU %d state\n", rc, nr);
 84                 return -ENODEV;
 85         }
 86 
 87         /*
 88          * Already started, just kick it, probably coming from
 89          * kexec and spinning
 90          */
 91         if (status == OPAL_THREAD_STARTED)
 92                 goto kick;
 93 
 94         /*
 95          * Available/inactive, let's kick it
 96          */
 97         if (status == OPAL_THREAD_INACTIVE) {
 98                 pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n", nr, pcpu);
 99                 rc = opal_start_cpu(pcpu, start_here);
100                 if (rc != OPAL_SUCCESS) {
101                         pr_warn("OPAL Error %ld starting CPU %d\n", rc, nr);
102                         return -ENODEV;
103                 }
104         } else {
105                 /*
106                  * An unavailable CPU (or any other unknown status)
107                  * shouldn't be started. It should also
108                  * not be in the possible map but currently it can
109                  * happen
110                  */
111                 pr_devel("OPAL: CPU %d (HW 0x%x) is unavailable"
112                          " (status %d)...\n", nr, pcpu, status);
113                 return -ENODEV;
114         }
115 
116 kick:
117         return smp_generic_kick_cpu(nr);
118 }
119 
120 #ifdef CONFIG_HOTPLUG_CPU
121 
122 static int pnv_smp_cpu_disable(void)
123 {
124         int cpu = smp_processor_id();
125 
126         /* This is identical to pSeries... might consolidate by
127          * moving migrate_irqs_away to a ppc_md with default to
128          * the generic fixup_irqs. --BenH.
129          */
130         set_cpu_online(cpu, false);
131         vdso_data->processorCount--;
132         if (cpu == boot_cpuid)
133                 boot_cpuid = cpumask_any(cpu_online_mask);
134         xics_migrate_irqs_away();
135         return 0;
136 }
137 
138 static void pnv_smp_cpu_kill_self(void)
139 {
140         unsigned int cpu;
141         unsigned long srr1, wmask;
142         u32 idle_states;
143 
144         /* Standard hot unplug procedure */
145         local_irq_disable();
146         idle_task_exit();
147         current->active_mm = NULL; /* for sanity */
148         cpu = smp_processor_id();
149         DBG("CPU%d offline\n", cpu);
150         generic_set_cpu_dead(cpu);
151         smp_wmb();
152 
153         wmask = SRR1_WAKEMASK;
154         if (cpu_has_feature(CPU_FTR_ARCH_207S))
155                 wmask = SRR1_WAKEMASK_P8;
156 
157         idle_states = pnv_get_supported_cpuidle_states();
158         /* We don't want to take decrementer interrupts while we are offline,
159          * so clear LPCR:PECE1. We keep PECE2 enabled.
160          */
161         mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1);
162 
163         /*
164          * Hard-disable interrupts, and then clear irq_happened flags
165          * that we can safely ignore while off-line, since they
166          * are for things for which we do no processing when off-line
167          * (or in the case of HMI, all the processing we need to do
168          * is done in lower-level real-mode code).
169          */
170         hard_irq_disable();
171         local_paca->irq_happened &= ~(PACA_IRQ_DEC | PACA_IRQ_HMI);
172 
173         while (!generic_check_cpu_restart(cpu)) {
174                 /*
175                  * Clear IPI flag, since we don't handle IPIs while
176                  * offline, except for those when changing micro-threading
177                  * mode, which are handled explicitly below, and those
178                  * for coming online, which are handled via
179                  * generic_check_cpu_restart() calls.
180                  */
181                 kvmppc_set_host_ipi(cpu, 0);
182 
183                 ppc64_runlatch_off();
184 
185                 if (idle_states & OPAL_PM_WINKLE_ENABLED)
186                         srr1 = power7_winkle();
187                 else if ((idle_states & OPAL_PM_SLEEP_ENABLED) ||
188                                 (idle_states & OPAL_PM_SLEEP_ENABLED_ER1))
189                         srr1 = power7_sleep();
190                 else
191                         srr1 = power7_nap(1);
192 
193                 ppc64_runlatch_on();
194 
195                 /*
196                  * If the SRR1 value indicates that we woke up due to
197                  * an external interrupt, then clear the interrupt.
198                  * We clear the interrupt before checking for the
199                  * reason, so as to avoid a race where we wake up for
200                  * some other reason, find nothing and clear the interrupt
201                  * just as some other cpu is sending us an interrupt.
202                  * If we returned from power7_nap as a result of
203                  * having finished executing in a KVM guest, then srr1
204                  * contains 0.
205                  */
206                 if (((srr1 & wmask) == SRR1_WAKEEE) ||
207                     (local_paca->irq_happened & PACA_IRQ_EE)) {
208                         icp_native_flush_interrupt();
209                 } else if ((srr1 & wmask) == SRR1_WAKEHDBELL) {
210                         unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER);
211                         asm volatile(PPC_MSGCLR(%0) : : "r" (msg));
212                 }
213                 local_paca->irq_happened &= ~(PACA_IRQ_EE | PACA_IRQ_DBELL);
214                 smp_mb();
215 
216                 if (cpu_core_split_required())
217                         continue;
218 
219                 if (srr1 && !generic_check_cpu_restart(cpu))
220                         DBG("CPU%d Unexpected exit while offline !\n", cpu);
221         }
222         mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1);
223         DBG("CPU%d coming online...\n", cpu);
224 }
225 
226 #endif /* CONFIG_HOTPLUG_CPU */
227 
228 static int pnv_cpu_bootable(unsigned int nr)
229 {
230         /*
231          * Starting with POWER8, the subcore logic relies on all threads of a
232          * core being booted so that they can participate in split mode
233          * switches. So on those machines we ignore the smt_enabled_at_boot
234          * setting (smt-enabled on the kernel command line).
235          */
236         if (cpu_has_feature(CPU_FTR_ARCH_207S))
237                 return 1;
238 
239         return smp_generic_cpu_bootable(nr);
240 }
241 
242 static struct smp_ops_t pnv_smp_ops = {
243         .message_pass   = smp_muxed_ipi_message_pass,
244         .cause_ipi      = NULL, /* Filled at runtime by xics_smp_probe() */
245         .probe          = xics_smp_probe,
246         .kick_cpu       = pnv_smp_kick_cpu,
247         .setup_cpu      = pnv_smp_setup_cpu,
248         .cpu_bootable   = pnv_cpu_bootable,
249 #ifdef CONFIG_HOTPLUG_CPU
250         .cpu_disable    = pnv_smp_cpu_disable,
251         .cpu_die        = generic_cpu_die,
252 #endif /* CONFIG_HOTPLUG_CPU */
253 };
254 
255 /* This is called very early during platform setup_arch */
256 void __init pnv_smp_init(void)
257 {
258         smp_ops = &pnv_smp_ops;
259 
260 #ifdef CONFIG_HOTPLUG_CPU
261         ppc_md.cpu_die  = pnv_smp_cpu_kill_self;
262 #endif
263 }
264 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp