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> 3555190f88SBenjamin Herrenschmidt 3655190f88SBenjamin Herrenschmidt #include "powernv.h" 3755190f88SBenjamin Herrenschmidt 38344eb010SBenjamin Herrenschmidt #ifdef DEBUG 39344eb010SBenjamin Herrenschmidt #include <asm/udbg.h> 40344eb010SBenjamin Herrenschmidt #define DBG(fmt...) udbg_printf(fmt) 41344eb010SBenjamin Herrenschmidt #else 42344eb010SBenjamin Herrenschmidt #define DBG(fmt...) 43344eb010SBenjamin Herrenschmidt #endif 44344eb010SBenjamin Herrenschmidt 45061d19f2SPaul Gortmaker static void pnv_smp_setup_cpu(int cpu) 4655190f88SBenjamin Herrenschmidt { 4755190f88SBenjamin Herrenschmidt if (cpu != boot_cpuid) 4855190f88SBenjamin Herrenschmidt xics_setup_cpu(); 4955190f88SBenjamin Herrenschmidt } 5055190f88SBenjamin Herrenschmidt 51cad5cef6SGreg Kroah-Hartman int pnv_smp_kick_cpu(int nr) 5214a43e69SBenjamin Herrenschmidt { 5314a43e69SBenjamin Herrenschmidt unsigned int pcpu = get_hard_smp_processor_id(nr); 542751b628SAnton Blanchard unsigned long start_here = 552751b628SAnton Blanchard __pa(ppc_function_entry(generic_secondary_smp_init)); 5614a43e69SBenjamin Herrenschmidt long rc; 5714a43e69SBenjamin Herrenschmidt 5814a43e69SBenjamin Herrenschmidt BUG_ON(nr < 0 || nr >= NR_CPUS); 5914a43e69SBenjamin Herrenschmidt 60b2b48584SBenjamin Herrenschmidt /* 61b2b48584SBenjamin Herrenschmidt * If we already started or OPALv2 is not supported, we just 62b2b48584SBenjamin Herrenschmidt * kick the CPU via the PACA 6314a43e69SBenjamin Herrenschmidt */ 64b2b48584SBenjamin Herrenschmidt if (paca[nr].cpu_start || !firmware_has_feature(FW_FEATURE_OPALv2)) 65b2b48584SBenjamin Herrenschmidt goto kick; 66b2b48584SBenjamin Herrenschmidt 67b2b48584SBenjamin Herrenschmidt /* 68b2b48584SBenjamin Herrenschmidt * At this point, the CPU can either be spinning on the way in 69b2b48584SBenjamin Herrenschmidt * from kexec or be inside OPAL waiting to be started for the 70b2b48584SBenjamin Herrenschmidt * first time. OPAL v3 allows us to query OPAL to know if it 71b2b48584SBenjamin Herrenschmidt * has the CPUs, so we do that 72b2b48584SBenjamin Herrenschmidt */ 73b2b48584SBenjamin Herrenschmidt if (firmware_has_feature(FW_FEATURE_OPALv3)) { 74b2b48584SBenjamin Herrenschmidt uint8_t status; 75b2b48584SBenjamin Herrenschmidt 76b2b48584SBenjamin Herrenschmidt rc = opal_query_cpu_status(pcpu, &status); 77b2b48584SBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 78b2b48584SBenjamin Herrenschmidt pr_warn("OPAL Error %ld querying CPU %d state\n", 79b2b48584SBenjamin Herrenschmidt rc, nr); 80b2b48584SBenjamin Herrenschmidt return -ENODEV; 81b2b48584SBenjamin Herrenschmidt } 82b2b48584SBenjamin Herrenschmidt 83b2b48584SBenjamin Herrenschmidt /* 84b2b48584SBenjamin Herrenschmidt * Already started, just kick it, probably coming from 85b2b48584SBenjamin Herrenschmidt * kexec and spinning 86b2b48584SBenjamin Herrenschmidt */ 87b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_STARTED) 88b2b48584SBenjamin Herrenschmidt goto kick; 89b2b48584SBenjamin Herrenschmidt 90b2b48584SBenjamin Herrenschmidt /* 91b2b48584SBenjamin Herrenschmidt * Available/inactive, let's kick it 92b2b48584SBenjamin Herrenschmidt */ 93b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_INACTIVE) { 94b2b48584SBenjamin Herrenschmidt pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n", 95b2b48584SBenjamin Herrenschmidt nr, pcpu); 9614a43e69SBenjamin Herrenschmidt rc = opal_start_cpu(pcpu, start_here); 974ea9008bSBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 9814a43e69SBenjamin Herrenschmidt pr_warn("OPAL Error %ld starting CPU %d\n", 9914a43e69SBenjamin Herrenschmidt rc, nr); 1004ea9008bSBenjamin Herrenschmidt return -ENODEV; 1014ea9008bSBenjamin Herrenschmidt } 102b2b48584SBenjamin Herrenschmidt } else { 103b2b48584SBenjamin Herrenschmidt /* 104b2b48584SBenjamin Herrenschmidt * An unavailable CPU (or any other unknown status) 105b2b48584SBenjamin Herrenschmidt * shouldn't be started. It should also 106b2b48584SBenjamin Herrenschmidt * not be in the possible map but currently it can 107b2b48584SBenjamin Herrenschmidt * happen 108b2b48584SBenjamin Herrenschmidt */ 109b2b48584SBenjamin Herrenschmidt pr_devel("OPAL: CPU %d (HW 0x%x) is unavailable" 110b2b48584SBenjamin Herrenschmidt " (status %d)...\n", nr, pcpu, status); 111b2b48584SBenjamin Herrenschmidt return -ENODEV; 11214a43e69SBenjamin Herrenschmidt } 113b2b48584SBenjamin Herrenschmidt } else { 114b2b48584SBenjamin Herrenschmidt /* 115b2b48584SBenjamin Herrenschmidt * On OPAL v2, we just kick it and hope for the best, 116b2b48584SBenjamin Herrenschmidt * we must not test the error from opal_start_cpu() or 117b2b48584SBenjamin Herrenschmidt * we would fail to get CPUs from kexec. 118b2b48584SBenjamin Herrenschmidt */ 119b2b48584SBenjamin Herrenschmidt opal_start_cpu(pcpu, start_here); 120b2b48584SBenjamin Herrenschmidt } 121b2b48584SBenjamin Herrenschmidt kick: 12214a43e69SBenjamin Herrenschmidt return smp_generic_kick_cpu(nr); 12314a43e69SBenjamin Herrenschmidt } 12414a43e69SBenjamin Herrenschmidt 125344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 126344eb010SBenjamin Herrenschmidt 127344eb010SBenjamin Herrenschmidt static int pnv_smp_cpu_disable(void) 128344eb010SBenjamin Herrenschmidt { 129344eb010SBenjamin Herrenschmidt int cpu = smp_processor_id(); 130344eb010SBenjamin Herrenschmidt 131344eb010SBenjamin Herrenschmidt /* This is identical to pSeries... might consolidate by 132344eb010SBenjamin Herrenschmidt * moving migrate_irqs_away to a ppc_md with default to 133344eb010SBenjamin Herrenschmidt * the generic fixup_irqs. --BenH. 134344eb010SBenjamin Herrenschmidt */ 135344eb010SBenjamin Herrenschmidt set_cpu_online(cpu, false); 136344eb010SBenjamin Herrenschmidt vdso_data->processorCount--; 137344eb010SBenjamin Herrenschmidt if (cpu == boot_cpuid) 138344eb010SBenjamin Herrenschmidt boot_cpuid = cpumask_any(cpu_online_mask); 139344eb010SBenjamin Herrenschmidt xics_migrate_irqs_away(); 140344eb010SBenjamin Herrenschmidt return 0; 141344eb010SBenjamin Herrenschmidt } 142344eb010SBenjamin Herrenschmidt 143344eb010SBenjamin Herrenschmidt static void pnv_smp_cpu_kill_self(void) 144344eb010SBenjamin Herrenschmidt { 145344eb010SBenjamin Herrenschmidt unsigned int cpu; 146344eb010SBenjamin Herrenschmidt 147344eb010SBenjamin Herrenschmidt /* Standard hot unplug procedure */ 148344eb010SBenjamin Herrenschmidt local_irq_disable(); 149344eb010SBenjamin Herrenschmidt idle_task_exit(); 150344eb010SBenjamin Herrenschmidt current->active_mm = NULL; /* for sanity */ 151344eb010SBenjamin Herrenschmidt cpu = smp_processor_id(); 152344eb010SBenjamin Herrenschmidt DBG("CPU%d offline\n", cpu); 153344eb010SBenjamin Herrenschmidt generic_set_cpu_dead(cpu); 154344eb010SBenjamin Herrenschmidt smp_wmb(); 155344eb010SBenjamin Herrenschmidt 156344eb010SBenjamin Herrenschmidt /* We don't want to take decrementer interrupts while we are offline, 157344eb010SBenjamin Herrenschmidt * so clear LPCR:PECE1. We keep PECE2 enabled. 158344eb010SBenjamin Herrenschmidt */ 159344eb010SBenjamin Herrenschmidt mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) & ~(u64)LPCR_PECE1); 160344eb010SBenjamin Herrenschmidt while (!generic_check_cpu_restart(cpu)) { 161f2038911SPreeti U Murthy ppc64_runlatch_off(); 1628d6f7c5aSMichael Ellerman power7_nap(1); 163f2038911SPreeti U Murthy ppc64_runlatch_on(); 164e2186023SMichael Ellerman 165e2186023SMichael Ellerman /* Reenable IRQs briefly to clear the IPI that woke us */ 166344eb010SBenjamin Herrenschmidt local_irq_enable(); 167344eb010SBenjamin Herrenschmidt local_irq_disable(); 168e2186023SMichael Ellerman mb(); 169e2186023SMichael Ellerman 170e2186023SMichael Ellerman if (cpu_core_split_required()) 171e2186023SMichael Ellerman continue; 172e2186023SMichael Ellerman 173e2186023SMichael Ellerman if (!generic_check_cpu_restart(cpu)) 174e2186023SMichael Ellerman DBG("CPU%d Unexpected exit while offline !\n", cpu); 175344eb010SBenjamin Herrenschmidt } 176344eb010SBenjamin Herrenschmidt mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1); 177344eb010SBenjamin Herrenschmidt DBG("CPU%d coming online...\n", cpu); 178344eb010SBenjamin Herrenschmidt } 179344eb010SBenjamin Herrenschmidt 180344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 181344eb010SBenjamin Herrenschmidt 18255190f88SBenjamin Herrenschmidt static struct smp_ops_t pnv_smp_ops = { 18355190f88SBenjamin Herrenschmidt .message_pass = smp_muxed_ipi_message_pass, 18455190f88SBenjamin Herrenschmidt .cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */ 18555190f88SBenjamin Herrenschmidt .probe = xics_smp_probe, 18614a43e69SBenjamin Herrenschmidt .kick_cpu = pnv_smp_kick_cpu, 18755190f88SBenjamin Herrenschmidt .setup_cpu = pnv_smp_setup_cpu, 18839fd4027SAndy Fleming .cpu_bootable = smp_generic_cpu_bootable, 189344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 190344eb010SBenjamin Herrenschmidt .cpu_disable = pnv_smp_cpu_disable, 191344eb010SBenjamin Herrenschmidt .cpu_die = generic_cpu_die, 192344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 19355190f88SBenjamin Herrenschmidt }; 19455190f88SBenjamin Herrenschmidt 19555190f88SBenjamin Herrenschmidt /* This is called very early during platform setup_arch */ 19655190f88SBenjamin Herrenschmidt void __init pnv_smp_init(void) 19755190f88SBenjamin Herrenschmidt { 19855190f88SBenjamin Herrenschmidt smp_ops = &pnv_smp_ops; 19955190f88SBenjamin Herrenschmidt 20055190f88SBenjamin Herrenschmidt /* XXX We don't yet have a proper entry point from HAL, for 20155190f88SBenjamin Herrenschmidt * now we rely on kexec-style entry from BML 20255190f88SBenjamin Herrenschmidt */ 20355190f88SBenjamin Herrenschmidt 20455190f88SBenjamin Herrenschmidt #ifdef CONFIG_PPC_RTAS 20555190f88SBenjamin Herrenschmidt /* Non-lpar has additional take/give timebase */ 20655190f88SBenjamin Herrenschmidt if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { 20755190f88SBenjamin Herrenschmidt smp_ops->give_timebase = rtas_give_timebase; 20855190f88SBenjamin Herrenschmidt smp_ops->take_timebase = rtas_take_timebase; 20955190f88SBenjamin Herrenschmidt } 21055190f88SBenjamin Herrenschmidt #endif /* CONFIG_PPC_RTAS */ 211344eb010SBenjamin Herrenschmidt 212344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 213344eb010SBenjamin Herrenschmidt ppc_md.cpu_die = pnv_smp_cpu_kill_self; 214344eb010SBenjamin Herrenschmidt #endif 21555190f88SBenjamin Herrenschmidt } 216