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> 3355190f88SBenjamin Herrenschmidt 3455190f88SBenjamin Herrenschmidt #include "powernv.h" 3555190f88SBenjamin Herrenschmidt 36344eb010SBenjamin Herrenschmidt #ifdef DEBUG 37344eb010SBenjamin Herrenschmidt #include <asm/udbg.h> 38344eb010SBenjamin Herrenschmidt #define DBG(fmt...) udbg_printf(fmt) 39344eb010SBenjamin Herrenschmidt #else 40344eb010SBenjamin Herrenschmidt #define DBG(fmt...) 41344eb010SBenjamin Herrenschmidt #endif 42344eb010SBenjamin Herrenschmidt 43061d19f2SPaul Gortmaker static void pnv_smp_setup_cpu(int cpu) 4455190f88SBenjamin Herrenschmidt { 4555190f88SBenjamin Herrenschmidt if (cpu != boot_cpuid) 4655190f88SBenjamin Herrenschmidt xics_setup_cpu(); 4755190f88SBenjamin Herrenschmidt } 4855190f88SBenjamin Herrenschmidt 4955190f88SBenjamin Herrenschmidt static int pnv_smp_cpu_bootable(unsigned int nr) 5055190f88SBenjamin Herrenschmidt { 5155190f88SBenjamin Herrenschmidt /* Special case - we inhibit secondary thread startup 5255190f88SBenjamin Herrenschmidt * during boot if the user requests it. 5355190f88SBenjamin Herrenschmidt */ 54a5b45dedSliguang if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) { 5555190f88SBenjamin Herrenschmidt if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0) 5655190f88SBenjamin Herrenschmidt return 0; 5755190f88SBenjamin Herrenschmidt if (smt_enabled_at_boot 5855190f88SBenjamin Herrenschmidt && cpu_thread_in_core(nr) >= smt_enabled_at_boot) 5955190f88SBenjamin Herrenschmidt return 0; 6055190f88SBenjamin Herrenschmidt } 6155190f88SBenjamin Herrenschmidt 6255190f88SBenjamin Herrenschmidt return 1; 6355190f88SBenjamin Herrenschmidt } 6455190f88SBenjamin Herrenschmidt 65cad5cef6SGreg Kroah-Hartman int pnv_smp_kick_cpu(int nr) 6614a43e69SBenjamin Herrenschmidt { 6714a43e69SBenjamin Herrenschmidt unsigned int pcpu = get_hard_smp_processor_id(nr); 6814a43e69SBenjamin Herrenschmidt unsigned long start_here = __pa(*((unsigned long *) 6914a43e69SBenjamin Herrenschmidt generic_secondary_smp_init)); 7014a43e69SBenjamin Herrenschmidt long rc; 7114a43e69SBenjamin Herrenschmidt 7214a43e69SBenjamin Herrenschmidt BUG_ON(nr < 0 || nr >= NR_CPUS); 7314a43e69SBenjamin Herrenschmidt 74b2b48584SBenjamin Herrenschmidt /* 75b2b48584SBenjamin Herrenschmidt * If we already started or OPALv2 is not supported, we just 76b2b48584SBenjamin Herrenschmidt * kick the CPU via the PACA 7714a43e69SBenjamin Herrenschmidt */ 78b2b48584SBenjamin Herrenschmidt if (paca[nr].cpu_start || !firmware_has_feature(FW_FEATURE_OPALv2)) 79b2b48584SBenjamin Herrenschmidt goto kick; 80b2b48584SBenjamin Herrenschmidt 81b2b48584SBenjamin Herrenschmidt /* 82b2b48584SBenjamin Herrenschmidt * At this point, the CPU can either be spinning on the way in 83b2b48584SBenjamin Herrenschmidt * from kexec or be inside OPAL waiting to be started for the 84b2b48584SBenjamin Herrenschmidt * first time. OPAL v3 allows us to query OPAL to know if it 85b2b48584SBenjamin Herrenschmidt * has the CPUs, so we do that 86b2b48584SBenjamin Herrenschmidt */ 87b2b48584SBenjamin Herrenschmidt if (firmware_has_feature(FW_FEATURE_OPALv3)) { 88b2b48584SBenjamin Herrenschmidt uint8_t status; 89b2b48584SBenjamin Herrenschmidt 90b2b48584SBenjamin Herrenschmidt rc = opal_query_cpu_status(pcpu, &status); 91b2b48584SBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 92b2b48584SBenjamin Herrenschmidt pr_warn("OPAL Error %ld querying CPU %d state\n", 93b2b48584SBenjamin Herrenschmidt rc, nr); 94b2b48584SBenjamin Herrenschmidt return -ENODEV; 95b2b48584SBenjamin Herrenschmidt } 96b2b48584SBenjamin Herrenschmidt 97b2b48584SBenjamin Herrenschmidt /* 98b2b48584SBenjamin Herrenschmidt * Already started, just kick it, probably coming from 99b2b48584SBenjamin Herrenschmidt * kexec and spinning 100b2b48584SBenjamin Herrenschmidt */ 101b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_STARTED) 102b2b48584SBenjamin Herrenschmidt goto kick; 103b2b48584SBenjamin Herrenschmidt 104b2b48584SBenjamin Herrenschmidt /* 105b2b48584SBenjamin Herrenschmidt * Available/inactive, let's kick it 106b2b48584SBenjamin Herrenschmidt */ 107b2b48584SBenjamin Herrenschmidt if (status == OPAL_THREAD_INACTIVE) { 108b2b48584SBenjamin Herrenschmidt pr_devel("OPAL: Starting CPU %d (HW 0x%x)...\n", 109b2b48584SBenjamin Herrenschmidt nr, pcpu); 11014a43e69SBenjamin Herrenschmidt rc = opal_start_cpu(pcpu, start_here); 1114ea9008bSBenjamin Herrenschmidt if (rc != OPAL_SUCCESS) { 11214a43e69SBenjamin Herrenschmidt pr_warn("OPAL Error %ld starting CPU %d\n", 11314a43e69SBenjamin Herrenschmidt rc, nr); 1144ea9008bSBenjamin Herrenschmidt return -ENODEV; 1154ea9008bSBenjamin Herrenschmidt } 116b2b48584SBenjamin Herrenschmidt } else { 117b2b48584SBenjamin Herrenschmidt /* 118b2b48584SBenjamin Herrenschmidt * An unavailable CPU (or any other unknown status) 119b2b48584SBenjamin Herrenschmidt * shouldn't be started. It should also 120b2b48584SBenjamin Herrenschmidt * not be in the possible map but currently it can 121b2b48584SBenjamin Herrenschmidt * happen 122b2b48584SBenjamin Herrenschmidt */ 123b2b48584SBenjamin Herrenschmidt pr_devel("OPAL: CPU %d (HW 0x%x) is unavailable" 124b2b48584SBenjamin Herrenschmidt " (status %d)...\n", nr, pcpu, status); 125b2b48584SBenjamin Herrenschmidt return -ENODEV; 12614a43e69SBenjamin Herrenschmidt } 127b2b48584SBenjamin Herrenschmidt } else { 128b2b48584SBenjamin Herrenschmidt /* 129b2b48584SBenjamin Herrenschmidt * On OPAL v2, we just kick it and hope for the best, 130b2b48584SBenjamin Herrenschmidt * we must not test the error from opal_start_cpu() or 131b2b48584SBenjamin Herrenschmidt * we would fail to get CPUs from kexec. 132b2b48584SBenjamin Herrenschmidt */ 133b2b48584SBenjamin Herrenschmidt opal_start_cpu(pcpu, start_here); 134b2b48584SBenjamin Herrenschmidt } 135b2b48584SBenjamin Herrenschmidt kick: 13614a43e69SBenjamin Herrenschmidt return smp_generic_kick_cpu(nr); 13714a43e69SBenjamin Herrenschmidt } 13814a43e69SBenjamin Herrenschmidt 139344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 140344eb010SBenjamin Herrenschmidt 141344eb010SBenjamin Herrenschmidt static int pnv_smp_cpu_disable(void) 142344eb010SBenjamin Herrenschmidt { 143344eb010SBenjamin Herrenschmidt int cpu = smp_processor_id(); 144344eb010SBenjamin Herrenschmidt 145344eb010SBenjamin Herrenschmidt /* This is identical to pSeries... might consolidate by 146344eb010SBenjamin Herrenschmidt * moving migrate_irqs_away to a ppc_md with default to 147344eb010SBenjamin Herrenschmidt * the generic fixup_irqs. --BenH. 148344eb010SBenjamin Herrenschmidt */ 149344eb010SBenjamin Herrenschmidt set_cpu_online(cpu, false); 150344eb010SBenjamin Herrenschmidt vdso_data->processorCount--; 151344eb010SBenjamin Herrenschmidt if (cpu == boot_cpuid) 152344eb010SBenjamin Herrenschmidt boot_cpuid = cpumask_any(cpu_online_mask); 153344eb010SBenjamin Herrenschmidt xics_migrate_irqs_away(); 154344eb010SBenjamin Herrenschmidt return 0; 155344eb010SBenjamin Herrenschmidt } 156344eb010SBenjamin Herrenschmidt 157344eb010SBenjamin Herrenschmidt static void pnv_smp_cpu_kill_self(void) 158344eb010SBenjamin Herrenschmidt { 159344eb010SBenjamin Herrenschmidt unsigned int cpu; 160344eb010SBenjamin Herrenschmidt 161344eb010SBenjamin Herrenschmidt /* Standard hot unplug procedure */ 162344eb010SBenjamin Herrenschmidt local_irq_disable(); 163344eb010SBenjamin Herrenschmidt idle_task_exit(); 164344eb010SBenjamin Herrenschmidt current->active_mm = NULL; /* for sanity */ 165344eb010SBenjamin Herrenschmidt cpu = smp_processor_id(); 166344eb010SBenjamin Herrenschmidt DBG("CPU%d offline\n", cpu); 167344eb010SBenjamin Herrenschmidt generic_set_cpu_dead(cpu); 168344eb010SBenjamin Herrenschmidt smp_wmb(); 169344eb010SBenjamin Herrenschmidt 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); 174344eb010SBenjamin Herrenschmidt while (!generic_check_cpu_restart(cpu)) { 175375f561aSPaul Mackerras power7_nap(); 176344eb010SBenjamin Herrenschmidt if (!generic_check_cpu_restart(cpu)) { 177344eb010SBenjamin Herrenschmidt DBG("CPU%d Unexpected exit while offline !\n", cpu); 178344eb010SBenjamin Herrenschmidt /* We may be getting an IPI, so we re-enable 179344eb010SBenjamin Herrenschmidt * interrupts to process it, it will be ignored 180344eb010SBenjamin Herrenschmidt * since we aren't online (hopefully) 181344eb010SBenjamin Herrenschmidt */ 182344eb010SBenjamin Herrenschmidt local_irq_enable(); 183344eb010SBenjamin Herrenschmidt local_irq_disable(); 184344eb010SBenjamin Herrenschmidt } 185344eb010SBenjamin Herrenschmidt } 186344eb010SBenjamin Herrenschmidt mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_PECE1); 187344eb010SBenjamin Herrenschmidt DBG("CPU%d coming online...\n", cpu); 188344eb010SBenjamin Herrenschmidt } 189344eb010SBenjamin Herrenschmidt 190344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 191344eb010SBenjamin Herrenschmidt 19255190f88SBenjamin Herrenschmidt static struct smp_ops_t pnv_smp_ops = { 19355190f88SBenjamin Herrenschmidt .message_pass = smp_muxed_ipi_message_pass, 19455190f88SBenjamin Herrenschmidt .cause_ipi = NULL, /* Filled at runtime by xics_smp_probe() */ 19555190f88SBenjamin Herrenschmidt .probe = xics_smp_probe, 19614a43e69SBenjamin Herrenschmidt .kick_cpu = pnv_smp_kick_cpu, 19755190f88SBenjamin Herrenschmidt .setup_cpu = pnv_smp_setup_cpu, 19855190f88SBenjamin Herrenschmidt .cpu_bootable = pnv_smp_cpu_bootable, 199344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 200344eb010SBenjamin Herrenschmidt .cpu_disable = pnv_smp_cpu_disable, 201344eb010SBenjamin Herrenschmidt .cpu_die = generic_cpu_die, 202344eb010SBenjamin Herrenschmidt #endif /* CONFIG_HOTPLUG_CPU */ 20355190f88SBenjamin Herrenschmidt }; 20455190f88SBenjamin Herrenschmidt 20555190f88SBenjamin Herrenschmidt /* This is called very early during platform setup_arch */ 20655190f88SBenjamin Herrenschmidt void __init pnv_smp_init(void) 20755190f88SBenjamin Herrenschmidt { 20855190f88SBenjamin Herrenschmidt smp_ops = &pnv_smp_ops; 20955190f88SBenjamin Herrenschmidt 21055190f88SBenjamin Herrenschmidt /* XXX We don't yet have a proper entry point from HAL, for 21155190f88SBenjamin Herrenschmidt * now we rely on kexec-style entry from BML 21255190f88SBenjamin Herrenschmidt */ 21355190f88SBenjamin Herrenschmidt 21455190f88SBenjamin Herrenschmidt #ifdef CONFIG_PPC_RTAS 21555190f88SBenjamin Herrenschmidt /* Non-lpar has additional take/give timebase */ 21655190f88SBenjamin Herrenschmidt if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { 21755190f88SBenjamin Herrenschmidt smp_ops->give_timebase = rtas_give_timebase; 21855190f88SBenjamin Herrenschmidt smp_ops->take_timebase = rtas_take_timebase; 21955190f88SBenjamin Herrenschmidt } 22055190f88SBenjamin Herrenschmidt #endif /* CONFIG_PPC_RTAS */ 221344eb010SBenjamin Herrenschmidt 222344eb010SBenjamin Herrenschmidt #ifdef CONFIG_HOTPLUG_CPU 223344eb010SBenjamin Herrenschmidt ppc_md.cpu_die = pnv_smp_cpu_kill_self; 224344eb010SBenjamin Herrenschmidt #endif 22555190f88SBenjamin Herrenschmidt } 226