155190f88SBenjamin Herrenschmidt /* 255190f88SBenjamin Herrenschmidt * SMP support for PowerNV machines. 355190f88SBenjamin Herrenschmidt * 455190f88SBenjamin Herrenschmidt * Copyright 2011 IBM Corp. 555190f88SBenjamin Herrenschmidt * 655190f88SBenjamin Herrenschmidt * This program is free software; you can redistribute it and/or 755190f88SBenjamin Herrenschmidt * modify it under the terms of the GNU General Public License 855190f88SBenjamin Herrenschmidt * as published by the Free Software Foundation; either version 955190f88SBenjamin Herrenschmidt * 2 of the License, or (at your option) any later version. 1055190f88SBenjamin Herrenschmidt */ 1155190f88SBenjamin Herrenschmidt 1255190f88SBenjamin Herrenschmidt #include <linux/kernel.h> 1355190f88SBenjamin Herrenschmidt #include <linux/module.h> 1455190f88SBenjamin Herrenschmidt #include <linux/sched.h> 1555190f88SBenjamin Herrenschmidt #include <linux/smp.h> 1655190f88SBenjamin Herrenschmidt #include <linux/interrupt.h> 1755190f88SBenjamin Herrenschmidt #include <linux/delay.h> 1855190f88SBenjamin Herrenschmidt #include <linux/init.h> 1955190f88SBenjamin Herrenschmidt #include <linux/spinlock.h> 2055190f88SBenjamin Herrenschmidt #include <linux/cpu.h> 2155190f88SBenjamin Herrenschmidt 2255190f88SBenjamin Herrenschmidt #include <asm/irq.h> 2355190f88SBenjamin Herrenschmidt #include <asm/smp.h> 2455190f88SBenjamin Herrenschmidt #include <asm/paca.h> 2555190f88SBenjamin Herrenschmidt #include <asm/machdep.h> 2655190f88SBenjamin Herrenschmidt #include <asm/cputable.h> 2755190f88SBenjamin Herrenschmidt #include <asm/firmware.h> 2855190f88SBenjamin Herrenschmidt #include <asm/vdso_datapage.h> 2955190f88SBenjamin Herrenschmidt #include <asm/cputhreads.h> 3055190f88SBenjamin Herrenschmidt #include <asm/xics.h> 3114a43e69SBenjamin Herrenschmidt #include <asm/opal.h> 32f2038911SPreeti U Murthy #include <asm/runlatch.h> 332751b628SAnton Blanchard #include <asm/code-patching.h> 34d4e58e59SMichael Neuling #include <asm/dbell.h> 35755563bcSPaul Mackerras #include <asm/kvm_ppc.h> 36755563bcSPaul Mackerras #include <asm/ppc-opcode.h> 3755190f88SBenjamin Herrenschmidt 3855190f88SBenjamin Herrenschmidt #include "powernv.h" 3955190f88SBenjamin Herrenschmidt 40344eb010SBenjamin Herrenschmidt #ifdef DEBUG 41344eb010SBenjamin Herrenschmidt #include <asm/udbg.h> 42344eb010SBenjamin Herrenschmidt #define DBG(fmt...) udbg_printf(fmt) 43344eb010SBenjamin Herrenschmidt #else 44344eb010SBenjamin Herrenschmidt #define DBG(fmt...) 45344eb010SBenjamin Herrenschmidt #endif 46344eb010SBenjamin Herrenschmidt 47061d19f2SPaul Gortmaker static void pnv_smp_setup_cpu(int cpu) 4855190f88SBenjamin Herrenschmidt { 4955190f88SBenjamin Herrenschmidt if (cpu != boot_cpuid) 5055190f88SBenjamin Herrenschmidt xics_setup_cpu(); 51d4e58e59SMichael Neuling 52d4e58e59SMichael Neuling #ifdef CONFIG_PPC_DOORBELL 53d4e58e59SMichael Neuling if (cpu_has_feature(CPU_FTR_DBELL)) 54d4e58e59SMichael Neuling doorbell_setup_this_cpu(); 55d4e58e59SMichael Neuling #endif 5655190f88SBenjamin Herrenschmidt } 5755190f88SBenjamin Herrenschmidt 58e51df2c1SAnton Blanchard static int pnv_smp_kick_cpu(int nr) 5914a43e69SBenjamin Herrenschmidt { 6014a43e69SBenjamin Herrenschmidt unsigned int pcpu = get_hard_smp_processor_id(nr); 612751b628SAnton Blanchard unsigned long start_here = 622751b628SAnton Blanchard __pa(ppc_function_entry(generic_secondary_smp_init)); 6314a43e69SBenjamin Herrenschmidt long rc; 6414a43e69SBenjamin Herrenschmidt 6514a43e69SBenjamin Herrenschmidt BUG_ON(nr < 0 || nr >= NR_CPUS); 6614a43e69SBenjamin Herrenschmidt 67b2b48584SBenjamin Herrenschmidt /* 68b2b48584SBenjamin Herrenschmidt * If we already started or OPALv2 is not supported, we just 69b2b48584SBenjamin Herrenschmidt * kick the CPU via the PACA 7014a43e69SBenjamin Herrenschmidt */ 71b2b48584SBenjamin Herrenschmidt if (paca[nr].cpu_start || !firmware_has_feature(FW_FEATURE_OPALv2)) 72b2b48584SBenjamin Herrenschmidt goto kick; 73b2b48584SBenjamin Herrenschmidt 74b2b48584SBenjamin Herrenschmidt /* 75b2b48584SBenjamin Herrenschmidt * At this point, the CPU can either be spinning on the way in 76b2b48584SBenjamin Herrenschmidt * from kexec or be inside OPAL waiting to be started for the 77b2b48584SBenjamin Herrenschmidt * first time. OPAL v3 allows us to query OPAL to know if it 78b2b48584SBenjamin Herrenschmidt * has the CPUs, so we do that 79b2b48584SBenjamin Herrenschmidt */ 80b2b48584SBenjamin Herrenschmidt if (firmware_has_feature(FW_FEATURE_OPALv3)) { 81b2b48584SBenjamin Herrenschmidt uint8_t status; 82b2b48584SBenjamin Herrenschmidt 83b2b48584SBenjamin Herrenschmidt rc = opal_query_cpu_status(pcpu, &status); 84b2b48584SBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 85b2b48584SBenjamin Herrenschmidt pr_warn("OPAL Error %ld querying CPU %d state\n", 86b2b48584SBenjamin Herrenschmidt rc, nr); 87b2b48584SBenjamin Herrenschmidt return -ENODEV; 88b2b48584SBenjamin Herrenschmidt } 89b2b48584SBenjamin Herrenschmidt 90b2b48584SBenjamin Herrenschmidt /* 91b2b48584SBenjamin Herrenschmidt * Already started, just kick it, probably coming from 92b2b48584SBenjamin Herrenschmidt * kexec and spinning 93b2b48584SBenjamin Herrenschmidt */ 94b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_STARTED) 95b2b48584SBenjamin Herrenschmidt goto kick; 96b2b48584SBenjamin Herrenschmidt 97b2b48584SBenjamin Herrenschmidt /* 98b2b48584SBenjamin Herrenschmidt * Available/inactive, let's kick it 99b2b48584SBenjamin Herrenschmidt */ 100b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_INACTIVE) { 101b2b48584SBenjamin Herrenschmidt pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n", 102b2b48584SBenjamin Herrenschmidt nr, pcpu); 10314a43e69SBenjamin Herrenschmidt rc = opal_start_cpu(pcpu, start_here); 1044ea9008bSBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 10514a43e69SBenjamin Herrenschmidt pr_warn("OPAL Error %ld starting CPU %d\n", 10614a43e69SBenjamin Herrenschmidt rc, nr); 1074ea9008bSBenjamin Herrenschmidt return -ENODEV; 1084ea9008bSBenjamin Herrenschmidt } 109b2b48584SBenjamin Herrenschmidt } else { 110b2b48584SBenjamin Herrenschmidt /* 111b2b48584SBenjamin Herrenschmidt * An unavailable CPU (or any other unknown status) 112b2b48584SBenjamin Herrenschmidt * shouldn't be started. It should also 113b2b48584SBenjamin Herrenschmidt * not be in the possible map but currently it can 114b2b48584SBenjamin Herrenschmidt * happen 115b2b48584SBenjamin Herrenschmidt */ 116b2b48584SBenjamin Herrenschmidt pr_devel("OPAL: CPU %d (HW 0x%x) is unavailable" 117b2b48584SBenjamin Herrenschmidt " (status %d)...\n", nr, pcpu, status); 118b2b48584SBenjamin Herrenschmidt return -ENODEV; 11914a43e69SBenjamin Herrenschmidt } 120b2b48584SBenjamin Herrenschmidt } else { 121b2b48584SBenjamin Herrenschmidt /* 122b2b48584SBenjamin Herrenschmidt * On OPAL v2, we just kick it and hope for the best, 123b2b48584SBenjamin Herrenschmidt * we must not test the error from opal_start_cpu() or 124b2b48584SBenjamin Herrenschmidt * we would fail to get CPUs from kexec. 125b2b48584SBenjamin Herrenschmidt */ 126b2b48584SBenjamin Herrenschmidt opal_start_cpu(pcpu, start_here); 127b2b48584SBenjamin Herrenschmidt } 128b2b48584SBenjamin Herrenschmidt kick: 12914a43e69SBenjamin Herrenschmidt return smp_generic_kick_cpu(nr); 13014a43e69SBenjamin Herrenschmidt } 13114a43e69SBenjamin Herrenschmidt 132344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 133344eb010SBenjamin Herrenschmidt 134344eb010SBenjamin Herrenschmidt static int pnv_smp_cpu_disable(void) 135344eb010SBenjamin Herrenschmidt { 136344eb010SBenjamin Herrenschmidt int cpu = smp_processor_id(); 137344eb010SBenjamin Herrenschmidt 138344eb010SBenjamin Herrenschmidt /* This is identical to pSeries... might consolidate by 139344eb010SBenjamin Herrenschmidt * moving migrate_irqs_away to a ppc_md with default to 140344eb010SBenjamin Herrenschmidt * the generic fixup_irqs. --BenH. 141344eb010SBenjamin Herrenschmidt */ 142344eb010SBenjamin Herrenschmidt set_cpu_online(cpu, false); 143344eb010SBenjamin Herrenschmidt vdso_data->processorCount--; 144344eb010SBenjamin Herrenschmidt if (cpu == boot_cpuid) 145344eb010SBenjamin Herrenschmidt boot_cpuid = cpumask_any(cpu_online_mask); 146344eb010SBenjamin Herrenschmidt xics_migrate_irqs_away(); 147344eb010SBenjamin Herrenschmidt return 0; 148344eb010SBenjamin Herrenschmidt } 149344eb010SBenjamin Herrenschmidt 150344eb010SBenjamin Herrenschmidt static void pnv_smp_cpu_kill_self(void) 151344eb010SBenjamin Herrenschmidt { 152344eb010SBenjamin Herrenschmidt unsigned int cpu; 153755563bcSPaul Mackerras unsigned long srr1, wmask; 1548eb8ac89SShreyas B. Prabhu u32 idle_states; 155344eb010SBenjamin Herrenschmidt 156344eb010SBenjamin Herrenschmidt /* Standard hot unplug procedure */ 157344eb010SBenjamin Herrenschmidt local_irq_disable(); 158344eb010SBenjamin Herrenschmidt idle_task_exit(); 159344eb010SBenjamin Herrenschmidt current->active_mm = NULL; /* for sanity */ 160344eb010SBenjamin Herrenschmidt cpu = smp_processor_id(); 161344eb010SBenjamin Herrenschmidt DBG("CPU%d offline\n", cpu); 162344eb010SBenjamin Herrenschmidt generic_set_cpu_dead(cpu); 163344eb010SBenjamin Herrenschmidt smp_wmb(); 164344eb010SBenjamin Herrenschmidt 165755563bcSPaul Mackerras wmask = SRR1_WAKEMASK; 166755563bcSPaul Mackerras if (cpu_has_feature(CPU_FTR_ARCH_207S)) 167755563bcSPaul Mackerras wmask = SRR1_WAKEMASK_P8; 168755563bcSPaul Mackerras 1698eb8ac89SShreyas B. Prabhu idle_states = pnv_get_supported_cpuidle_states(); 170344eb010SBenjamin Herrenschmidt /* We don't want to take decrementer interrupts while we are offline, 171344eb010SBenjamin Herrenschmidt * so clear LPCR:PECE1. We keep PECE2 enabled. 172344eb010SBenjamin Herrenschmidt */ 173344eb010SBenjamin Herrenschmidt mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1); 17453c656c4SPaul Mackerras 17553c656c4SPaul Mackerras /* 17653c656c4SPaul Mackerras * Hard-disable interrupts, and then clear irq_happened flags 17753c656c4SPaul Mackerras * that we can safely ignore while off-line, since they 17853c656c4SPaul Mackerras * are for things for which we do no processing when off-line 17953c656c4SPaul Mackerras * (or in the case of HMI, all the processing we need to do 18053c656c4SPaul Mackerras * is done in lower-level real-mode code). 18153c656c4SPaul Mackerras */ 18253c656c4SPaul Mackerras hard_irq_disable(); 18353c656c4SPaul Mackerras local_paca->irq_happened &= ~(PACA_IRQ_DEC | PACA_IRQ_HMI); 18453c656c4SPaul Mackerras 185344eb010SBenjamin Herrenschmidt while (!generic_check_cpu_restart(cpu)) { 18653c656c4SPaul Mackerras /* 18753c656c4SPaul Mackerras * Clear IPI flag, since we don't handle IPIs while 18853c656c4SPaul Mackerras * offline, except for those when changing micro-threading 18953c656c4SPaul Mackerras * mode, which are handled explicitly below, and those 19053c656c4SPaul Mackerras * for coming online, which are handled via 19153c656c4SPaul Mackerras * generic_check_cpu_restart() calls. 19253c656c4SPaul Mackerras */ 19353c656c4SPaul Mackerras kvmppc_set_host_ipi(cpu, 0); 19477b54e9fSShreyas B. Prabhu 195f2038911SPreeti U Murthy ppc64_runlatch_off(); 19677b54e9fSShreyas B. Prabhu 19777b54e9fSShreyas B. Prabhu if (idle_states & OPAL_PM_WINKLE_ENABLED) 19877b54e9fSShreyas B. Prabhu srr1 = power7_winkle(); 19977b54e9fSShreyas B. Prabhu else if ((idle_states & OPAL_PM_SLEEP_ENABLED) || 2007cba160aSShreyas B. Prabhu (idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) 2018eb8ac89SShreyas B. Prabhu srr1 = power7_sleep(); 2028eb8ac89SShreyas B. Prabhu else 20356548fc0SPaul Mackerras srr1 = power7_nap(1); 20477b54e9fSShreyas B. Prabhu 205f2038911SPreeti U Murthy ppc64_runlatch_on(); 206e2186023SMichael Ellerman 20756548fc0SPaul Mackerras /* 20856548fc0SPaul Mackerras * If the SRR1 value indicates that we woke up due to 20956548fc0SPaul Mackerras * an external interrupt, then clear the interrupt. 21056548fc0SPaul Mackerras * We clear the interrupt before checking for the 21156548fc0SPaul Mackerras * reason, so as to avoid a race where we wake up for 21256548fc0SPaul Mackerras * some other reason, find nothing and clear the interrupt 21356548fc0SPaul Mackerras * just as some other cpu is sending us an interrupt. 21456548fc0SPaul Mackerras * If we returned from power7_nap as a result of 21556548fc0SPaul Mackerras * having finished executing in a KVM guest, then srr1 21656548fc0SPaul Mackerras * contains 0. 21756548fc0SPaul Mackerras */ 21853c656c4SPaul Mackerras if (((srr1 & wmask) == SRR1_WAKEEE) || 21953c656c4SPaul Mackerras (local_paca->irq_happened & PACA_IRQ_EE)) { 220d6a4f709SPaul Mackerras icp_native_flush_interrupt(); 221755563bcSPaul Mackerras } else if ((srr1 & wmask) == SRR1_WAKEHDBELL) { 222755563bcSPaul Mackerras unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER); 223755563bcSPaul Mackerras asm volatile(PPC_MSGCLR(%0) : : "r" (msg)); 22456548fc0SPaul Mackerras } 22553c656c4SPaul Mackerras local_paca->irq_happened &= ~(PACA_IRQ_EE | PACA_IRQ_DBELL); 22653c656c4SPaul Mackerras smp_mb(); 227e2186023SMichael Ellerman 228e2186023SMichael Ellerman if (cpu_core_split_required()) 229e2186023SMichael Ellerman continue; 230e2186023SMichael Ellerman 23153c656c4SPaul Mackerras if (srr1 && !generic_check_cpu_restart(cpu)) 232e2186023SMichael Ellerman DBG("CPU%d Unexpected exit while offline !\n", cpu); 233344eb010SBenjamin Herrenschmidt } 234344eb010SBenjamin Herrenschmidt mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1); 235344eb010SBenjamin Herrenschmidt DBG("CPU%d coming online...\n", cpu); 236344eb010SBenjamin Herrenschmidt } 237344eb010SBenjamin Herrenschmidt 238344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 239344eb010SBenjamin Herrenschmidt 240d70a54e2SGreg Kurz static int pnv_cpu_bootable(unsigned int nr) 241d70a54e2SGreg Kurz { 242d70a54e2SGreg Kurz /* 243d70a54e2SGreg Kurz * Starting with POWER8, the subcore logic relies on all threads of a 244d70a54e2SGreg Kurz * core being booted so that they can participate in split mode 245d70a54e2SGreg Kurz * switches. So on those machines we ignore the smt_enabled_at_boot 246d70a54e2SGreg Kurz * setting (smt-enabled on the kernel command line). 247d70a54e2SGreg Kurz */ 248d70a54e2SGreg Kurz if (cpu_has_feature(CPU_FTR_ARCH_207S)) 249d70a54e2SGreg Kurz return 1; 250d70a54e2SGreg Kurz 251d70a54e2SGreg Kurz return smp_generic_cpu_bootable(nr); 252d70a54e2SGreg Kurz } 253d70a54e2SGreg Kurz 25455190f88SBenjamin Herrenschmidt static struct smp_ops_t pnv_smp_ops = { 25555190f88SBenjamin Herrenschmidt .message_pass = smp_muxed_ipi_message_pass, 25655190f88SBenjamin Herrenschmidt .cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */ 25755190f88SBenjamin Herrenschmidt .probe = xics_smp_probe, 25814a43e69SBenjamin Herrenschmidt .kick_cpu = pnv_smp_kick_cpu, 25955190f88SBenjamin Herrenschmidt .setup_cpu = pnv_smp_setup_cpu, 260d70a54e2SGreg Kurz .cpu_bootable = pnv_cpu_bootable, 261344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 262344eb010SBenjamin Herrenschmidt .cpu_disable = pnv_smp_cpu_disable, 263344eb010SBenjamin Herrenschmidt .cpu_die = generic_cpu_die, 264344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 26555190f88SBenjamin Herrenschmidt }; 26655190f88SBenjamin Herrenschmidt 26755190f88SBenjamin Herrenschmidt /* This is called very early during platform setup_arch */ 26855190f88SBenjamin Herrenschmidt void __init pnv_smp_init(void) 26955190f88SBenjamin Herrenschmidt { 27055190f88SBenjamin Herrenschmidt smp_ops = &pnv_smp_ops; 27155190f88SBenjamin Herrenschmidt 272344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 273344eb010SBenjamin Herrenschmidt ppc_md.cpu_die = pnv_smp_cpu_kill_self; 274344eb010SBenjamin Herrenschmidt #endif 27555190f88SBenjamin Herrenschmidt } 276