169a80d3fSPaul Mackerras /* 269a80d3fSPaul Mackerras * SMP support for pSeries machines. 369a80d3fSPaul Mackerras * 469a80d3fSPaul Mackerras * Dave Engebretsen, Peter Bergner, and 569a80d3fSPaul Mackerras * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com 669a80d3fSPaul Mackerras * 769a80d3fSPaul Mackerras * Plus various changes from other IBM teams... 869a80d3fSPaul Mackerras * 969a80d3fSPaul Mackerras * This program is free software; you can redistribute it and/or 1069a80d3fSPaul Mackerras * modify it under the terms of the GNU General Public License 1169a80d3fSPaul Mackerras * as published by the Free Software Foundation; either version 1269a80d3fSPaul Mackerras * 2 of the License, or (at your option) any later version. 1369a80d3fSPaul Mackerras */ 1469a80d3fSPaul Mackerras 1569a80d3fSPaul Mackerras 1669a80d3fSPaul Mackerras #include <linux/kernel.h> 1769a80d3fSPaul Mackerras #include <linux/sched.h> 1869a80d3fSPaul Mackerras #include <linux/smp.h> 1969a80d3fSPaul Mackerras #include <linux/interrupt.h> 2069a80d3fSPaul Mackerras #include <linux/delay.h> 2169a80d3fSPaul Mackerras #include <linux/init.h> 2269a80d3fSPaul Mackerras #include <linux/spinlock.h> 2369a80d3fSPaul Mackerras #include <linux/cache.h> 2469a80d3fSPaul Mackerras #include <linux/err.h> 25edbaa603SKay Sievers #include <linux/device.h> 2669a80d3fSPaul Mackerras #include <linux/cpu.h> 2769a80d3fSPaul Mackerras 2869a80d3fSPaul Mackerras #include <asm/ptrace.h> 2960063497SArun Sharma #include <linux/atomic.h> 3069a80d3fSPaul Mackerras #include <asm/irq.h> 3169a80d3fSPaul Mackerras #include <asm/page.h> 3269a80d3fSPaul Mackerras #include <asm/pgtable.h> 3369a80d3fSPaul Mackerras #include <asm/io.h> 3469a80d3fSPaul Mackerras #include <asm/prom.h> 3569a80d3fSPaul Mackerras #include <asm/smp.h> 3669a80d3fSPaul Mackerras #include <asm/paca.h> 3769a80d3fSPaul Mackerras #include <asm/machdep.h> 3869a80d3fSPaul Mackerras #include <asm/cputable.h> 3969a80d3fSPaul Mackerras #include <asm/firmware.h> 4069a80d3fSPaul Mackerras #include <asm/rtas.h> 41271c3f35SPaul Mackerras #include <asm/vdso_datapage.h> 428d089085SBenjamin Herrenschmidt #include <asm/cputhreads.h> 430b05ac6eSBenjamin Herrenschmidt #include <asm/xics.h> 44eac1e731SCédric Le Goater #include <asm/xive.h> 45e5e84f0aSIan Munsie #include <asm/dbell.h> 46212bebb4SDeepthi Dharwar #include <asm/plpar_wrappers.h> 472751b628SAnton Blanchard #include <asm/code-patching.h> 4869a80d3fSPaul Mackerras 498feaeca2SMichael Ellerman #include "pseries.h" 503aa565f5SGautham R Shenoy #include "offline_states.h" 51a1218720SMichael Ellerman 5269a80d3fSPaul Mackerras 5369a80d3fSPaul Mackerras /* 546a75a6b8SMilton Miller * The Primary thread of each non-boot processor was started from the OF client 556a75a6b8SMilton Miller * interface by prom_hold_cpus and is spinning on secondary_hold_spinloop. 5669a80d3fSPaul Mackerras */ 57af831e1eSAnton Blanchard static cpumask_var_t of_spin_mask; 5869a80d3fSPaul Mackerras 59f8b67691SMichael Neuling /* Query where a cpu is now. Return codes #defined in plpar_wrappers.h */ 60f8b67691SMichael Neuling int smp_query_cpu_stopped(unsigned int pcpu) 61f8b67691SMichael Neuling { 62f8b67691SMichael Neuling int cpu_status, status; 63f8b67691SMichael Neuling int qcss_tok = rtas_token("query-cpu-stopped-state"); 64f8b67691SMichael Neuling 65f8b67691SMichael Neuling if (qcss_tok == RTAS_UNKNOWN_SERVICE) { 662d86938aSMilton Miller printk_once(KERN_INFO 672d86938aSMilton Miller "Firmware doesn't support query-cpu-stopped-state\n"); 68f8b67691SMichael Neuling return QCSS_HARDWARE_ERROR; 69f8b67691SMichael Neuling } 70f8b67691SMichael Neuling 71f8b67691SMichael Neuling status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); 72f8b67691SMichael Neuling if (status != 0) { 73f8b67691SMichael Neuling printk(KERN_ERR 74f8b67691SMichael Neuling "RTAS query-cpu-stopped-state failed: %i\n", status); 75f8b67691SMichael Neuling return status; 76f8b67691SMichael Neuling } 77f8b67691SMichael Neuling 78f8b67691SMichael Neuling return cpu_status; 79f8b67691SMichael Neuling } 80f8b67691SMichael Neuling 8169a80d3fSPaul Mackerras /** 8269a80d3fSPaul Mackerras * smp_startup_cpu() - start the given cpu 8369a80d3fSPaul Mackerras * 8469a80d3fSPaul Mackerras * At boot time, there is nothing to do for primary threads which were 8569a80d3fSPaul Mackerras * started from Open Firmware. For anything else, call RTAS with the 8669a80d3fSPaul Mackerras * appropriate start location. 8769a80d3fSPaul Mackerras * 8869a80d3fSPaul Mackerras * Returns: 8969a80d3fSPaul Mackerras * 0 - failure 9069a80d3fSPaul Mackerras * 1 - success 9169a80d3fSPaul Mackerras */ 92cad5cef6SGreg Kroah-Hartman static inline int smp_startup_cpu(unsigned int lcpu) 9369a80d3fSPaul Mackerras { 9469a80d3fSPaul Mackerras int status; 952751b628SAnton Blanchard unsigned long start_here = 962751b628SAnton Blanchard __pa(ppc_function_entry(generic_secondary_smp_init)); 9769a80d3fSPaul Mackerras unsigned int pcpu; 9869a80d3fSPaul Mackerras int start_cpu; 9969a80d3fSPaul Mackerras 100af831e1eSAnton Blanchard if (cpumask_test_cpu(lcpu, of_spin_mask)) 10169a80d3fSPaul Mackerras /* Already started by OF and sitting in spin loop */ 10269a80d3fSPaul Mackerras return 1; 10369a80d3fSPaul Mackerras 10469a80d3fSPaul Mackerras pcpu = get_hard_smp_processor_id(lcpu); 10569a80d3fSPaul Mackerras 106aef40e87SMichael Neuling /* Check to see if the CPU out of FW already for kexec */ 107aef40e87SMichael Neuling if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){ 108af831e1eSAnton Blanchard cpumask_set_cpu(lcpu, of_spin_mask); 109aef40e87SMichael Neuling return 1; 110aef40e87SMichael Neuling } 111aef40e87SMichael Neuling 11269a80d3fSPaul Mackerras /* Fixup atomic count: it exited inside IRQ handler. */ 113b5e2fc1cSAl Viro task_thread_info(paca[lcpu].__current)->preempt_count = 0; 114c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1153aa565f5SGautham R Shenoy if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE) 1163aa565f5SGautham R Shenoy goto out; 117c60e65d7SMatt Evans #endif 11869a80d3fSPaul Mackerras /* 11969a80d3fSPaul Mackerras * If the RTAS start-cpu token does not exist then presume the 12069a80d3fSPaul Mackerras * cpu is already spinning. 12169a80d3fSPaul Mackerras */ 12269a80d3fSPaul Mackerras start_cpu = rtas_token("start-cpu"); 12369a80d3fSPaul Mackerras if (start_cpu == RTAS_UNKNOWN_SERVICE) 12469a80d3fSPaul Mackerras return 1; 12569a80d3fSPaul Mackerras 126496b7a51SMichael Ellerman status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, pcpu); 12769a80d3fSPaul Mackerras if (status != 0) { 12869a80d3fSPaul Mackerras printk(KERN_ERR "start-cpu failed: %i\n", status); 12969a80d3fSPaul Mackerras return 0; 13069a80d3fSPaul Mackerras } 13169a80d3fSPaul Mackerras 132c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1333aa565f5SGautham R Shenoy out: 134c60e65d7SMatt Evans #endif 13569a80d3fSPaul Mackerras return 1; 13669a80d3fSPaul Mackerras } 13769a80d3fSPaul Mackerras 13886425bedSRashmica Gupta static void smp_setup_cpu(int cpu) 13969a80d3fSPaul Mackerras { 140eac1e731SCédric Le Goater if (xive_enabled()) 141eac1e731SCédric Le Goater xive_smp_setup_cpu(); 142eac1e731SCédric Le Goater else if (cpu != boot_cpuid) 14369a80d3fSPaul Mackerras xics_setup_cpu(); 14469a80d3fSPaul Mackerras 14569a80d3fSPaul Mackerras if (firmware_has_feature(FW_FEATURE_SPLPAR)) 14669a80d3fSPaul Mackerras vpa_init(cpu); 14769a80d3fSPaul Mackerras 148af831e1eSAnton Blanchard cpumask_clear_cpu(cpu, of_spin_mask); 149c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1503aa565f5SGautham R Shenoy set_cpu_current_state(cpu, CPU_STATE_ONLINE); 1513aa565f5SGautham R Shenoy set_default_offline_state(cpu); 152c60e65d7SMatt Evans #endif 15369a80d3fSPaul Mackerras } 15469a80d3fSPaul Mackerras 155cad5cef6SGreg Kroah-Hartman static int smp_pSeries_kick_cpu(int nr) 15669a80d3fSPaul Mackerras { 157c642af9cSSantosh Sivaraj if (nr < 0 || nr >= nr_cpu_ids) 158f8d0d5dcSSantosh Sivaraj return -EINVAL; 15969a80d3fSPaul Mackerras 16069a80d3fSPaul Mackerras if (!smp_startup_cpu(nr)) 161de300974SMichael Ellerman return -ENOENT; 16269a80d3fSPaul Mackerras 16369a80d3fSPaul Mackerras /* 16469a80d3fSPaul Mackerras * The processor is currently spinning, waiting for the 16569a80d3fSPaul Mackerras * cpu_start field to become non-zero After we set cpu_start, 16669a80d3fSPaul Mackerras * the processor will continue on to secondary_start 16769a80d3fSPaul Mackerras */ 16869a80d3fSPaul Mackerras paca[nr].cpu_start = 1; 169c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1703aa565f5SGautham R Shenoy set_preferred_offline_state(nr, CPU_STATE_ONLINE); 1713aa565f5SGautham R Shenoy 1723aa565f5SGautham R Shenoy if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) { 173c60e65d7SMatt Evans long rc; 174c60e65d7SMatt Evans unsigned long hcpuid; 175c60e65d7SMatt Evans 1763aa565f5SGautham R Shenoy hcpuid = get_hard_smp_processor_id(nr); 1773aa565f5SGautham R Shenoy rc = plpar_hcall_norets(H_PROD, hcpuid); 1783aa565f5SGautham R Shenoy if (rc != H_SUCCESS) 1795a2ad98eSJoe Perches printk(KERN_ERR "Error: Prod to wake up processor %d " 1805a2ad98eSJoe Perches "Ret= %ld\n", nr, rc); 1813aa565f5SGautham R Shenoy } 182c60e65d7SMatt Evans #endif 183de300974SMichael Ellerman 184de300974SMichael Ellerman return 0; 18569a80d3fSPaul Mackerras } 18669a80d3fSPaul Mackerras 187eac1e731SCédric Le Goater static int pseries_smp_prepare_cpu(int cpu) 188eac1e731SCédric Le Goater { 189eac1e731SCédric Le Goater if (xive_enabled()) 190eac1e731SCédric Le Goater return xive_smp_prepare_cpu(cpu); 191eac1e731SCédric Le Goater return 0; 192eac1e731SCédric Le Goater } 193eac1e731SCédric Le Goater 194b866cc21SNicholas Piggin static void smp_pseries_cause_ipi(int cpu) 195e5e84f0aSIan Munsie { 196b866cc21SNicholas Piggin /* POWER9 should not use this handler */ 197b866cc21SNicholas Piggin if (doorbell_try_core_ipi(cpu)) 198b866cc21SNicholas Piggin return; 199b866cc21SNicholas Piggin 200b866cc21SNicholas Piggin icp_ops->cause_ipi(cpu); 201e5e84f0aSIan Munsie } 202e5e84f0aSIan Munsie 203102c05e8SNicholas Piggin static int pseries_cause_nmi_ipi(int cpu) 204102c05e8SNicholas Piggin { 205102c05e8SNicholas Piggin int hwcpu; 206102c05e8SNicholas Piggin 207102c05e8SNicholas Piggin if (cpu == NMI_IPI_ALL_OTHERS) { 208102c05e8SNicholas Piggin hwcpu = H_SIGNAL_SYS_RESET_ALL_OTHERS; 209102c05e8SNicholas Piggin } else { 210102c05e8SNicholas Piggin if (cpu < 0) { 211102c05e8SNicholas Piggin WARN_ONCE(true, "incorrect cpu parameter %d", cpu); 212102c05e8SNicholas Piggin return 0; 213102c05e8SNicholas Piggin } 214102c05e8SNicholas Piggin 215102c05e8SNicholas Piggin hwcpu = get_hard_smp_processor_id(cpu); 216102c05e8SNicholas Piggin } 217102c05e8SNicholas Piggin 2187c09c186SMichael Ellerman if (plpar_signal_sys_reset(hwcpu) == H_SUCCESS) 219102c05e8SNicholas Piggin return 1; 220102c05e8SNicholas Piggin 221102c05e8SNicholas Piggin return 0; 222102c05e8SNicholas Piggin } 223102c05e8SNicholas Piggin 224eac1e731SCédric Le Goater static __init void pSeries_smp_probe_xics(void) 225e5e84f0aSIan Munsie { 226a7f4ee1fSMichael Ellerman xics_smp_probe(); 227e5e84f0aSIan Munsie 228b866cc21SNicholas Piggin if (cpu_has_feature(CPU_FTR_DBELL)) 229b866cc21SNicholas Piggin smp_ops->cause_ipi = smp_pseries_cause_ipi; 230b866cc21SNicholas Piggin else 231b866cc21SNicholas Piggin smp_ops->cause_ipi = icp_ops->cause_ipi; 232e5e84f0aSIan Munsie } 233e5e84f0aSIan Munsie 234eac1e731SCédric Le Goater static __init void pSeries_smp_probe(void) 235eac1e731SCédric Le Goater { 236eac1e731SCédric Le Goater if (xive_enabled()) 237eac1e731SCédric Le Goater /* 238eac1e731SCédric Le Goater * Don't use P9 doorbells when XIVE is enabled. IPIs 239eac1e731SCédric Le Goater * using MMIOs should be faster 240eac1e731SCédric Le Goater */ 241eac1e731SCédric Le Goater xive_smp_probe(); 242eac1e731SCédric Le Goater else 243eac1e731SCédric Le Goater pSeries_smp_probe_xics(); 244eac1e731SCédric Le Goater } 245eac1e731SCédric Le Goater 24686425bedSRashmica Gupta static struct smp_ops_t pseries_smp_ops = { 2479ca980dcSPaul Mackerras .message_pass = NULL, /* Use smp_muxed_ipi_message_pass */ 248e5e84f0aSIan Munsie .cause_ipi = NULL, /* Filled at runtime by pSeries_smp_probe() */ 249102c05e8SNicholas Piggin .cause_nmi_ipi = pseries_cause_nmi_ipi, 250e5e84f0aSIan Munsie .probe = pSeries_smp_probe, 251eac1e731SCédric Le Goater .prepare_cpu = pseries_smp_prepare_cpu, 25269a80d3fSPaul Mackerras .kick_cpu = smp_pSeries_kick_cpu, 25386425bedSRashmica Gupta .setup_cpu = smp_setup_cpu, 25439fd4027SAndy Fleming .cpu_bootable = smp_generic_cpu_bootable, 25569a80d3fSPaul Mackerras }; 25669a80d3fSPaul Mackerras 25769a80d3fSPaul Mackerras /* This is called very early */ 25886425bedSRashmica Gupta void __init smp_init_pseries(void) 25969a80d3fSPaul Mackerras { 26069a80d3fSPaul Mackerras int i; 26169a80d3fSPaul Mackerras 262f7ebf352SMichael Ellerman pr_debug(" -> smp_init_pSeries()\n"); 26386425bedSRashmica Gupta smp_ops = &pseries_smp_ops; 26469a80d3fSPaul Mackerras 265af831e1eSAnton Blanchard alloc_bootmem_cpumask_var(&of_spin_mask); 266af831e1eSAnton Blanchard 267dbe78b40SBenjamin Herrenschmidt /* 268dbe78b40SBenjamin Herrenschmidt * Mark threads which are still spinning in hold loops 269dbe78b40SBenjamin Herrenschmidt * 270dbe78b40SBenjamin Herrenschmidt * We know prom_init will not have started them if RTAS supports 271dbe78b40SBenjamin Herrenschmidt * query-cpu-stopped-state. 272dbe78b40SBenjamin Herrenschmidt */ 273dbe78b40SBenjamin Herrenschmidt if (rtas_token("query-cpu-stopped-state") == RTAS_UNKNOWN_SERVICE) { 27469a80d3fSPaul Mackerras if (cpu_has_feature(CPU_FTR_SMT)) { 27569a80d3fSPaul Mackerras for_each_present_cpu(i) { 2766a75a6b8SMilton Miller if (cpu_thread_in_core(i) == 0) 277af831e1eSAnton Blanchard cpumask_set_cpu(i, of_spin_mask); 27869a80d3fSPaul Mackerras } 279dbe78b40SBenjamin Herrenschmidt } else 280af831e1eSAnton Blanchard cpumask_copy(of_spin_mask, cpu_present_mask); 28169a80d3fSPaul Mackerras 282af831e1eSAnton Blanchard cpumask_clear_cpu(boot_cpuid, of_spin_mask); 283dbe78b40SBenjamin Herrenschmidt } 28469a80d3fSPaul Mackerras 28569a80d3fSPaul Mackerras /* Non-lpar has additional take/give timebase */ 28669a80d3fSPaul Mackerras if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { 287c4007a2fSBenjamin Herrenschmidt smp_ops->give_timebase = rtas_give_timebase; 288c4007a2fSBenjamin Herrenschmidt smp_ops->take_timebase = rtas_take_timebase; 28969a80d3fSPaul Mackerras } 29069a80d3fSPaul Mackerras 291f7ebf352SMichael Ellerman pr_debug(" <- smp_init_pSeries()\n"); 29269a80d3fSPaul Mackerras } 293