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/rtas.h> 2955190f88SBenjamin Herrenschmidt #include <asm/vdso_datapage.h> 3055190f88SBenjamin Herrenschmidt #include <asm/cputhreads.h> 3155190f88SBenjamin Herrenschmidt #include <asm/xics.h> 3214a43e69SBenjamin Herrenschmidt #include <asm/opal.h> 33f2038911SPreeti U Murthy #include <asm/runlatch.h> 342751b628SAnton Blanchard #include <asm/code-patching.h> 35d4e58e59SMichael Neuling #include <asm/dbell.h> 3655190f88SBenjamin Herrenschmidt 3755190f88SBenjamin Herrenschmidt #include "powernv.h" 3855190f88SBenjamin Herrenschmidt 39344eb010SBenjamin Herrenschmidt #ifdef DEBUG 40344eb010SBenjamin Herrenschmidt #include <asm/udbg.h> 41344eb010SBenjamin Herrenschmidt #define DBG(fmt...) udbg_printf(fmt) 42344eb010SBenjamin Herrenschmidt #else 43344eb010SBenjamin Herrenschmidt #define DBG(fmt...) 44344eb010SBenjamin Herrenschmidt #endif 45344eb010SBenjamin Herrenschmidt 46061d19f2SPaul Gortmaker static void pnv_smp_setup_cpu(int cpu) 4755190f88SBenjamin Herrenschmidt { 4855190f88SBenjamin Herrenschmidt if (cpu != boot_cpuid) 4955190f88SBenjamin Herrenschmidt xics_setup_cpu(); 50d4e58e59SMichael Neuling 51d4e58e59SMichael Neuling #ifdef CONFIG_PPC_DOORBELL 52d4e58e59SMichael Neuling if (cpu_has_feature(CPU_FTR_DBELL)) 53d4e58e59SMichael Neuling doorbell_setup_this_cpu(); 54d4e58e59SMichael Neuling #endif 5555190f88SBenjamin Herrenschmidt } 5655190f88SBenjamin Herrenschmidt 57e51df2c1SAnton Blanchard static int pnv_smp_kick_cpu(int nr) 5814a43e69SBenjamin Herrenschmidt { 5914a43e69SBenjamin Herrenschmidt unsigned int pcpu = get_hard_smp_processor_id(nr); 602751b628SAnton Blanchard unsigned long start_here = 612751b628SAnton Blanchard __pa(ppc_function_entry(generic_secondary_smp_init)); 6214a43e69SBenjamin Herrenschmidt long rc; 6314a43e69SBenjamin Herrenschmidt 6414a43e69SBenjamin Herrenschmidt BUG_ON(nr < 0 || nr >= NR_CPUS); 6514a43e69SBenjamin Herrenschmidt 66b2b48584SBenjamin Herrenschmidt /* 67b2b48584SBenjamin Herrenschmidt * If we already started or OPALv2 is not supported, we just 68b2b48584SBenjamin Herrenschmidt * kick the CPU via the PACA 6914a43e69SBenjamin Herrenschmidt */ 70b2b48584SBenjamin Herrenschmidt if (paca[nr].cpu_start || !firmware_has_feature(FW_FEATURE_OPALv2)) 71b2b48584SBenjamin Herrenschmidt goto kick; 72b2b48584SBenjamin Herrenschmidt 73b2b48584SBenjamin Herrenschmidt /* 74b2b48584SBenjamin Herrenschmidt * At this point, the CPU can either be spinning on the way in 75b2b48584SBenjamin Herrenschmidt * from kexec or be inside OPAL waiting to be started for the 76b2b48584SBenjamin Herrenschmidt * first time. OPAL v3 allows us to query OPAL to know if it 77b2b48584SBenjamin Herrenschmidt * has the CPUs, so we do that 78b2b48584SBenjamin Herrenschmidt */ 79b2b48584SBenjamin Herrenschmidt if (firmware_has_feature(FW_FEATURE_OPALv3)) { 80b2b48584SBenjamin Herrenschmidt uint8_t status; 81b2b48584SBenjamin Herrenschmidt 82b2b48584SBenjamin Herrenschmidt rc = opal_query_cpu_status(pcpu, &status); 83b2b48584SBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 84b2b48584SBenjamin Herrenschmidt pr_warn("OPAL Error %ld querying CPU %d state\n", 85b2b48584SBenjamin Herrenschmidt rc, nr); 86b2b48584SBenjamin Herrenschmidt return -ENODEV; 87b2b48584SBenjamin Herrenschmidt } 88b2b48584SBenjamin Herrenschmidt 89b2b48584SBenjamin Herrenschmidt /* 90b2b48584SBenjamin Herrenschmidt * Already started, just kick it, probably coming from 91b2b48584SBenjamin Herrenschmidt * kexec and spinning 92b2b48584SBenjamin Herrenschmidt */ 93b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_STARTED) 94b2b48584SBenjamin Herrenschmidt goto kick; 95b2b48584SBenjamin Herrenschmidt 96b2b48584SBenjamin Herrenschmidt /* 97b2b48584SBenjamin Herrenschmidt * Available/inactive, let's kick it 98b2b48584SBenjamin Herrenschmidt */ 99b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_INACTIVE) { 100b2b48584SBenjamin Herrenschmidt pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n", 101b2b48584SBenjamin Herrenschmidt nr, pcpu); 10214a43e69SBenjamin Herrenschmidt rc = opal_start_cpu(pcpu, start_here); 1034ea9008bSBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 10414a43e69SBenjamin Herrenschmidt pr_warn("OPAL Error %ld starting CPU %d\n", 10514a43e69SBenjamin Herrenschmidt rc, nr); 1064ea9008bSBenjamin Herrenschmidt return -ENODEV; 1074ea9008bSBenjamin Herrenschmidt } 108b2b48584SBenjamin Herrenschmidt } else { 109b2b48584SBenjamin Herrenschmidt /* 110b2b48584SBenjamin Herrenschmidt * An unavailable CPU (or any other unknown status) 111b2b48584SBenjamin Herrenschmidt * shouldn't be started. It should also 112b2b48584SBenjamin Herrenschmidt * not be in the possible map but currently it can 113b2b48584SBenjamin Herrenschmidt * happen 114b2b48584SBenjamin Herrenschmidt */ 115b2b48584SBenjamin Herrenschmidt pr_devel("OPAL: CPU %d (HW 0x%x) is unavailable" 116b2b48584SBenjamin Herrenschmidt " (status %d)...\n", nr, pcpu, status); 117b2b48584SBenjamin Herrenschmidt return -ENODEV; 11814a43e69SBenjamin Herrenschmidt } 119b2b48584SBenjamin Herrenschmidt } else { 120b2b48584SBenjamin Herrenschmidt /* 121b2b48584SBenjamin Herrenschmidt * On OPAL v2, we just kick it and hope for the best, 122b2b48584SBenjamin Herrenschmidt * we must not test the error from opal_start_cpu() or 123b2b48584SBenjamin Herrenschmidt * we would fail to get CPUs from kexec. 124b2b48584SBenjamin Herrenschmidt */ 125b2b48584SBenjamin Herrenschmidt opal_start_cpu(pcpu, start_here); 126b2b48584SBenjamin Herrenschmidt } 127b2b48584SBenjamin Herrenschmidt kick: 12814a43e69SBenjamin Herrenschmidt return smp_generic_kick_cpu(nr); 12914a43e69SBenjamin Herrenschmidt } 13014a43e69SBenjamin Herrenschmidt 131344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 132344eb010SBenjamin Herrenschmidt 133344eb010SBenjamin Herrenschmidt static int pnv_smp_cpu_disable(void) 134344eb010SBenjamin Herrenschmidt { 135344eb010SBenjamin Herrenschmidt int cpu = smp_processor_id(); 136344eb010SBenjamin Herrenschmidt 137344eb010SBenjamin Herrenschmidt /* This is identical to pSeries... might consolidate by 138344eb010SBenjamin Herrenschmidt * moving migrate_irqs_away to a ppc_md with default to 139344eb010SBenjamin Herrenschmidt * the generic fixup_irqs. --BenH. 140344eb010SBenjamin Herrenschmidt */ 141344eb010SBenjamin Herrenschmidt set_cpu_online(cpu, false); 142344eb010SBenjamin Herrenschmidt vdso_data->processorCount--; 143344eb010SBenjamin Herrenschmidt if (cpu == boot_cpuid) 144344eb010SBenjamin Herrenschmidt boot_cpuid = cpumask_any(cpu_online_mask); 145344eb010SBenjamin Herrenschmidt xics_migrate_irqs_away(); 146344eb010SBenjamin Herrenschmidt return 0; 147344eb010SBenjamin Herrenschmidt } 148344eb010SBenjamin Herrenschmidt 149344eb010SBenjamin Herrenschmidt static void pnv_smp_cpu_kill_self(void) 150344eb010SBenjamin Herrenschmidt { 151344eb010SBenjamin Herrenschmidt unsigned int cpu; 15256548fc0SPaul Mackerras unsigned long srr1; 1538eb8ac89SShreyas B. Prabhu u32 idle_states; 154344eb010SBenjamin Herrenschmidt 155344eb010SBenjamin Herrenschmidt /* Standard hot unplug procedure */ 156344eb010SBenjamin Herrenschmidt local_irq_disable(); 157344eb010SBenjamin Herrenschmidt idle_task_exit(); 158344eb010SBenjamin Herrenschmidt current->active_mm = NULL; /* for sanity */ 159344eb010SBenjamin Herrenschmidt cpu = smp_processor_id(); 160344eb010SBenjamin Herrenschmidt DBG("CPU%d offline\n", cpu); 161344eb010SBenjamin Herrenschmidt generic_set_cpu_dead(cpu); 162344eb010SBenjamin Herrenschmidt smp_wmb(); 163344eb010SBenjamin Herrenschmidt 1648eb8ac89SShreyas B. Prabhu idle_states = pnv_get_supported_cpuidle_states(); 165344eb010SBenjamin Herrenschmidt /* We don't want to take decrementer interrupts while we are offline, 166344eb010SBenjamin Herrenschmidt * so clear LPCR:PECE1. We keep PECE2 enabled. 167344eb010SBenjamin Herrenschmidt */ 168344eb010SBenjamin Herrenschmidt mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1); 169344eb010SBenjamin Herrenschmidt while (!generic_check_cpu_restart(cpu)) { 170f2038911SPreeti U Murthy ppc64_runlatch_off(); 1717cba160aSShreyas B. Prabhu if ((idle_states & OPAL_PM_SLEEP_ENABLED) || 1727cba160aSShreyas B. Prabhu (idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) 1738eb8ac89SShreyas B. Prabhu srr1 = power7_sleep(); 1748eb8ac89SShreyas B. Prabhu else 17556548fc0SPaul Mackerras srr1 = power7_nap(1); 176f2038911SPreeti U Murthy ppc64_runlatch_on(); 177e2186023SMichael Ellerman 17856548fc0SPaul Mackerras /* 17956548fc0SPaul Mackerras * If the SRR1 value indicates that we woke up due to 18056548fc0SPaul Mackerras * an external interrupt, then clear the interrupt. 18156548fc0SPaul Mackerras * We clear the interrupt before checking for the 18256548fc0SPaul Mackerras * reason, so as to avoid a race where we wake up for 18356548fc0SPaul Mackerras * some other reason, find nothing and clear the interrupt 18456548fc0SPaul Mackerras * just as some other cpu is sending us an interrupt. 18556548fc0SPaul Mackerras * If we returned from power7_nap as a result of 18656548fc0SPaul Mackerras * having finished executing in a KVM guest, then srr1 18756548fc0SPaul Mackerras * contains 0. 18856548fc0SPaul Mackerras */ 18956548fc0SPaul Mackerras if ((srr1 & SRR1_WAKEMASK) == SRR1_WAKEEE) { 190d6a4f709SPaul Mackerras icp_native_flush_interrupt(); 191d6a4f709SPaul Mackerras local_paca->irq_happened &= PACA_IRQ_HARD_DIS; 19256548fc0SPaul Mackerras smp_mb(); 19356548fc0SPaul Mackerras } 194e2186023SMichael Ellerman 195e2186023SMichael Ellerman if (cpu_core_split_required()) 196e2186023SMichael Ellerman continue; 197e2186023SMichael Ellerman 198e2186023SMichael Ellerman if (!generic_check_cpu_restart(cpu)) 199e2186023SMichael Ellerman DBG("CPU%d Unexpected exit while offline !\n", cpu); 200344eb010SBenjamin Herrenschmidt } 201344eb010SBenjamin Herrenschmidt mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1); 202344eb010SBenjamin Herrenschmidt DBG("CPU%d coming online...\n", cpu); 203344eb010SBenjamin Herrenschmidt } 204344eb010SBenjamin Herrenschmidt 205344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 206344eb010SBenjamin Herrenschmidt 20755190f88SBenjamin Herrenschmidt static struct smp_ops_t pnv_smp_ops = { 20855190f88SBenjamin Herrenschmidt .message_pass = smp_muxed_ipi_message_pass, 20955190f88SBenjamin Herrenschmidt .cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */ 21055190f88SBenjamin Herrenschmidt .probe = xics_smp_probe, 21114a43e69SBenjamin Herrenschmidt .kick_cpu = pnv_smp_kick_cpu, 21255190f88SBenjamin Herrenschmidt .setup_cpu = pnv_smp_setup_cpu, 21339fd4027SAndy Fleming .cpu_bootable = smp_generic_cpu_bootable, 214344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 215344eb010SBenjamin Herrenschmidt .cpu_disable = pnv_smp_cpu_disable, 216344eb010SBenjamin Herrenschmidt .cpu_die = generic_cpu_die, 217344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 21855190f88SBenjamin Herrenschmidt }; 21955190f88SBenjamin Herrenschmidt 22055190f88SBenjamin Herrenschmidt /* This is called very early during platform setup_arch */ 22155190f88SBenjamin Herrenschmidt void __init pnv_smp_init(void) 22255190f88SBenjamin Herrenschmidt { 22355190f88SBenjamin Herrenschmidt smp_ops = &pnv_smp_ops; 22455190f88SBenjamin Herrenschmidt 22555190f88SBenjamin Herrenschmidt /* XXX We don't yet have a proper entry point from HAL, for 22655190f88SBenjamin Herrenschmidt * now we rely on kexec-style entry from BML 22755190f88SBenjamin Herrenschmidt */ 22855190f88SBenjamin Herrenschmidt 22955190f88SBenjamin Herrenschmidt #ifdef CONFIG_PPC_RTAS 23055190f88SBenjamin Herrenschmidt /* Non-lpar has additional take/give timebase */ 23155190f88SBenjamin Herrenschmidt if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { 23255190f88SBenjamin Herrenschmidt smp_ops->give_timebase = rtas_give_timebase; 23355190f88SBenjamin Herrenschmidt smp_ops->take_timebase = rtas_take_timebase; 23455190f88SBenjamin Herrenschmidt } 23555190f88SBenjamin Herrenschmidt #endif /* CONFIG_PPC_RTAS */ 236344eb010SBenjamin Herrenschmidt 237344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 238344eb010SBenjamin Herrenschmidt ppc_md.cpu_die = pnv_smp_cpu_kill_self; 239344eb010SBenjamin Herrenschmidt #endif 24055190f88SBenjamin Herrenschmidt } 241