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; 64e4d54f71SStewart Smith uint8_t status; 6514a43e69SBenjamin Herrenschmidt 6614a43e69SBenjamin Herrenschmidt BUG_ON(nr < 0 || nr >= NR_CPUS); 6714a43e69SBenjamin Herrenschmidt 68b2b48584SBenjamin Herrenschmidt /* 69e4d54f71SStewart Smith * If we already started or OPAL is not supported, we just 70b2b48584SBenjamin Herrenschmidt * kick the CPU via the PACA 7114a43e69SBenjamin Herrenschmidt */ 72e4d54f71SStewart Smith if (paca[nr].cpu_start || !firmware_has_feature(FW_FEATURE_OPAL)) 73b2b48584SBenjamin Herrenschmidt goto kick; 74b2b48584SBenjamin Herrenschmidt 75b2b48584SBenjamin Herrenschmidt /* 76b2b48584SBenjamin Herrenschmidt * At this point, the CPU can either be spinning on the way in 77b2b48584SBenjamin Herrenschmidt * from kexec or be inside OPAL waiting to be started for the 78b2b48584SBenjamin Herrenschmidt * first time. OPAL v3 allows us to query OPAL to know if it 79b2b48584SBenjamin Herrenschmidt * has the CPUs, so we do that 80b2b48584SBenjamin Herrenschmidt */ 81b2b48584SBenjamin Herrenschmidt rc = opal_query_cpu_status(pcpu, &status); 82b2b48584SBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 83e4d54f71SStewart Smith pr_warn("OPAL Error %ld querying CPU %d state\n", rc, nr); 84b2b48584SBenjamin Herrenschmidt return -ENODEV; 85b2b48584SBenjamin Herrenschmidt } 86b2b48584SBenjamin Herrenschmidt 87b2b48584SBenjamin Herrenschmidt /* 88b2b48584SBenjamin Herrenschmidt * Already started, just kick it, probably coming from 89b2b48584SBenjamin Herrenschmidt * kexec and spinning 90b2b48584SBenjamin Herrenschmidt */ 91b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_STARTED) 92b2b48584SBenjamin Herrenschmidt goto kick; 93b2b48584SBenjamin Herrenschmidt 94b2b48584SBenjamin Herrenschmidt /* 95b2b48584SBenjamin Herrenschmidt * Available/inactive, let's kick it 96b2b48584SBenjamin Herrenschmidt */ 97b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_INACTIVE) { 98e4d54f71SStewart Smith pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n", nr, pcpu); 9914a43e69SBenjamin Herrenschmidt rc = opal_start_cpu(pcpu, start_here); 1004ea9008bSBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 101e4d54f71SStewart Smith pr_warn("OPAL Error %ld starting CPU %d\n", rc, nr); 1024ea9008bSBenjamin Herrenschmidt return -ENODEV; 1034ea9008bSBenjamin Herrenschmidt } 104b2b48584SBenjamin Herrenschmidt } else { 105b2b48584SBenjamin Herrenschmidt /* 106b2b48584SBenjamin Herrenschmidt * An unavailable CPU (or any other unknown status) 107b2b48584SBenjamin Herrenschmidt * shouldn't be started. It should also 108b2b48584SBenjamin Herrenschmidt * not be in the possible map but currently it can 109b2b48584SBenjamin Herrenschmidt * happen 110b2b48584SBenjamin Herrenschmidt */ 111b2b48584SBenjamin Herrenschmidt pr_devel("OPAL: CPU %d (HW 0x%x) is unavailable" 112b2b48584SBenjamin Herrenschmidt " (status %d)...\n", nr, pcpu, status); 113b2b48584SBenjamin Herrenschmidt return -ENODEV; 11414a43e69SBenjamin Herrenschmidt } 115e4d54f71SStewart Smith 116b2b48584SBenjamin Herrenschmidt kick: 11714a43e69SBenjamin Herrenschmidt return smp_generic_kick_cpu(nr); 11814a43e69SBenjamin Herrenschmidt } 11914a43e69SBenjamin Herrenschmidt 120344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 121344eb010SBenjamin Herrenschmidt 122344eb010SBenjamin Herrenschmidt static int pnv_smp_cpu_disable(void) 123344eb010SBenjamin Herrenschmidt { 124344eb010SBenjamin Herrenschmidt int cpu = smp_processor_id(); 125344eb010SBenjamin Herrenschmidt 126344eb010SBenjamin Herrenschmidt /* This is identical to pSeries... might consolidate by 127344eb010SBenjamin Herrenschmidt * moving migrate_irqs_away to a ppc_md with default to 128344eb010SBenjamin Herrenschmidt * the generic fixup_irqs. --BenH. 129344eb010SBenjamin Herrenschmidt */ 130344eb010SBenjamin Herrenschmidt set_cpu_online(cpu, false); 131344eb010SBenjamin Herrenschmidt vdso_data->processorCount--; 132344eb010SBenjamin Herrenschmidt if (cpu == boot_cpuid) 133344eb010SBenjamin Herrenschmidt boot_cpuid = cpumask_any(cpu_online_mask); 134344eb010SBenjamin Herrenschmidt xics_migrate_irqs_away(); 135344eb010SBenjamin Herrenschmidt return 0; 136344eb010SBenjamin Herrenschmidt } 137344eb010SBenjamin Herrenschmidt 138344eb010SBenjamin Herrenschmidt static void pnv_smp_cpu_kill_self(void) 139344eb010SBenjamin Herrenschmidt { 140344eb010SBenjamin Herrenschmidt unsigned int cpu; 141755563bcSPaul Mackerras unsigned long srr1, wmask; 1428eb8ac89SShreyas B. Prabhu u32 idle_states; 143344eb010SBenjamin Herrenschmidt 144344eb010SBenjamin Herrenschmidt /* Standard hot unplug procedure */ 145344eb010SBenjamin Herrenschmidt local_irq_disable(); 146344eb010SBenjamin Herrenschmidt idle_task_exit(); 147344eb010SBenjamin Herrenschmidt current->active_mm = NULL; /* for sanity */ 148344eb010SBenjamin Herrenschmidt cpu = smp_processor_id(); 149344eb010SBenjamin Herrenschmidt DBG("CPU%d offline\n", cpu); 150344eb010SBenjamin Herrenschmidt generic_set_cpu_dead(cpu); 151344eb010SBenjamin Herrenschmidt smp_wmb(); 152344eb010SBenjamin Herrenschmidt 153755563bcSPaul Mackerras wmask = SRR1_WAKEMASK; 154755563bcSPaul Mackerras if (cpu_has_feature(CPU_FTR_ARCH_207S)) 155755563bcSPaul Mackerras wmask = SRR1_WAKEMASK_P8; 156755563bcSPaul Mackerras 1578eb8ac89SShreyas B. Prabhu idle_states = pnv_get_supported_cpuidle_states(); 158344eb010SBenjamin Herrenschmidt /* We don't want to take decrementer interrupts while we are offline, 159344eb010SBenjamin Herrenschmidt * so clear LPCR:PECE1. We keep PECE2 enabled. 160344eb010SBenjamin Herrenschmidt */ 161344eb010SBenjamin Herrenschmidt mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1); 16253c656c4SPaul Mackerras 16353c656c4SPaul Mackerras /* 16453c656c4SPaul Mackerras * Hard-disable interrupts, and then clear irq_happened flags 16553c656c4SPaul Mackerras * that we can safely ignore while off-line, since they 16653c656c4SPaul Mackerras * are for things for which we do no processing when off-line 16753c656c4SPaul Mackerras * (or in the case of HMI, all the processing we need to do 16853c656c4SPaul Mackerras * is done in lower-level real-mode code). 16953c656c4SPaul Mackerras */ 17053c656c4SPaul Mackerras hard_irq_disable(); 17153c656c4SPaul Mackerras local_paca->irq_happened &= ~(PACA_IRQ_DEC | PACA_IRQ_HMI); 17253c656c4SPaul Mackerras 173344eb010SBenjamin Herrenschmidt while (!generic_check_cpu_restart(cpu)) { 17453c656c4SPaul Mackerras /* 17553c656c4SPaul Mackerras * Clear IPI flag, since we don't handle IPIs while 17653c656c4SPaul Mackerras * offline, except for those when changing micro-threading 17753c656c4SPaul Mackerras * mode, which are handled explicitly below, and those 17853c656c4SPaul Mackerras * for coming online, which are handled via 17953c656c4SPaul Mackerras * generic_check_cpu_restart() calls. 18053c656c4SPaul Mackerras */ 18153c656c4SPaul Mackerras kvmppc_set_host_ipi(cpu, 0); 18277b54e9fSShreyas B. Prabhu 183f2038911SPreeti U Murthy ppc64_runlatch_off(); 18477b54e9fSShreyas B. Prabhu 18577b54e9fSShreyas B. Prabhu if (idle_states & OPAL_PM_WINKLE_ENABLED) 18677b54e9fSShreyas B. Prabhu srr1 = power7_winkle(); 18777b54e9fSShreyas B. Prabhu else if ((idle_states & OPAL_PM_SLEEP_ENABLED) || 1887cba160aSShreyas B. Prabhu (idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) 1898eb8ac89SShreyas B. Prabhu srr1 = power7_sleep(); 1908eb8ac89SShreyas B. Prabhu else 19156548fc0SPaul Mackerras srr1 = power7_nap(1); 19277b54e9fSShreyas B. Prabhu 193f2038911SPreeti U Murthy ppc64_runlatch_on(); 194e2186023SMichael Ellerman 19556548fc0SPaul Mackerras /* 19656548fc0SPaul Mackerras * If the SRR1 value indicates that we woke up due to 19756548fc0SPaul Mackerras * an external interrupt, then clear the interrupt. 19856548fc0SPaul Mackerras * We clear the interrupt before checking for the 19956548fc0SPaul Mackerras * reason, so as to avoid a race where we wake up for 20056548fc0SPaul Mackerras * some other reason, find nothing and clear the interrupt 20156548fc0SPaul Mackerras * just as some other cpu is sending us an interrupt. 20256548fc0SPaul Mackerras * If we returned from power7_nap as a result of 20356548fc0SPaul Mackerras * having finished executing in a KVM guest, then srr1 20456548fc0SPaul Mackerras * contains 0. 20556548fc0SPaul Mackerras */ 20653c656c4SPaul Mackerras if (((srr1 & wmask) == SRR1_WAKEEE) || 20753c656c4SPaul Mackerras (local_paca->irq_happened & PACA_IRQ_EE)) { 208d6a4f709SPaul Mackerras icp_native_flush_interrupt(); 209755563bcSPaul Mackerras } else if ((srr1 & wmask) == SRR1_WAKEHDBELL) { 210755563bcSPaul Mackerras unsigned long msg = PPC_DBELL_TYPE(PPC_DBELL_SERVER); 211755563bcSPaul Mackerras asm volatile(PPC_MSGCLR(%0) : : "r" (msg)); 21256548fc0SPaul Mackerras } 21353c656c4SPaul Mackerras local_paca->irq_happened &= ~(PACA_IRQ_EE | PACA_IRQ_DBELL); 21453c656c4SPaul Mackerras smp_mb(); 215e2186023SMichael Ellerman 216e2186023SMichael Ellerman if (cpu_core_split_required()) 217e2186023SMichael Ellerman continue; 218e2186023SMichael Ellerman 21953c656c4SPaul Mackerras if (srr1 && !generic_check_cpu_restart(cpu)) 220e2186023SMichael Ellerman DBG("CPU%d Unexpected exit while offline !\n", cpu); 221344eb010SBenjamin Herrenschmidt } 222344eb010SBenjamin Herrenschmidt mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1); 223344eb010SBenjamin Herrenschmidt DBG("CPU%d coming online...\n", cpu); 224344eb010SBenjamin Herrenschmidt } 225344eb010SBenjamin Herrenschmidt 226344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 227344eb010SBenjamin Herrenschmidt 228d70a54e2SGreg Kurz static int pnv_cpu_bootable(unsigned int nr) 229d70a54e2SGreg Kurz { 230d70a54e2SGreg Kurz /* 231d70a54e2SGreg Kurz * Starting with POWER8, the subcore logic relies on all threads of a 232d70a54e2SGreg Kurz * core being booted so that they can participate in split mode 233d70a54e2SGreg Kurz * switches. So on those machines we ignore the smt_enabled_at_boot 234d70a54e2SGreg Kurz * setting (smt-enabled on the kernel command line). 235d70a54e2SGreg Kurz */ 236d70a54e2SGreg Kurz if (cpu_has_feature(CPU_FTR_ARCH_207S)) 237d70a54e2SGreg Kurz return 1; 238d70a54e2SGreg Kurz 239d70a54e2SGreg Kurz return smp_generic_cpu_bootable(nr); 240d70a54e2SGreg Kurz } 241d70a54e2SGreg Kurz 24255190f88SBenjamin Herrenschmidt static struct smp_ops_t pnv_smp_ops = { 24355190f88SBenjamin Herrenschmidt .message_pass = smp_muxed_ipi_message_pass, 24455190f88SBenjamin Herrenschmidt .cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */ 24555190f88SBenjamin Herrenschmidt .probe = xics_smp_probe, 24614a43e69SBenjamin Herrenschmidt .kick_cpu = pnv_smp_kick_cpu, 24755190f88SBenjamin Herrenschmidt .setup_cpu = pnv_smp_setup_cpu, 248d70a54e2SGreg Kurz .cpu_bootable = pnv_cpu_bootable, 249344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 250344eb010SBenjamin Herrenschmidt .cpu_disable = pnv_smp_cpu_disable, 251344eb010SBenjamin Herrenschmidt .cpu_die = generic_cpu_die, 252344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 25355190f88SBenjamin Herrenschmidt }; 25455190f88SBenjamin Herrenschmidt 25555190f88SBenjamin Herrenschmidt /* This is called very early during platform setup_arch */ 25655190f88SBenjamin Herrenschmidt void __init pnv_smp_init(void) 25755190f88SBenjamin Herrenschmidt { 25855190f88SBenjamin Herrenschmidt smp_ops = &pnv_smp_ops; 25955190f88SBenjamin Herrenschmidt 260344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 261344eb010SBenjamin Herrenschmidt ppc_md.cpu_die = pnv_smp_cpu_kill_self; 262344eb010SBenjamin Herrenschmidt #endif 26355190f88SBenjamin Herrenschmidt } 264