12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 269a80d3fSPaul Mackerras /* 369a80d3fSPaul Mackerras * SMP support for pSeries machines. 469a80d3fSPaul Mackerras * 569a80d3fSPaul Mackerras * Dave Engebretsen, Peter Bergner, and 669a80d3fSPaul Mackerras * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com 769a80d3fSPaul Mackerras * 869a80d3fSPaul Mackerras * Plus various changes from other IBM teams... 969a80d3fSPaul Mackerras */ 1069a80d3fSPaul Mackerras 1169a80d3fSPaul Mackerras 1269a80d3fSPaul Mackerras #include <linux/kernel.h> 1369a80d3fSPaul Mackerras #include <linux/sched.h> 1469a80d3fSPaul Mackerras #include <linux/smp.h> 1569a80d3fSPaul Mackerras #include <linux/interrupt.h> 1669a80d3fSPaul Mackerras #include <linux/delay.h> 1769a80d3fSPaul Mackerras #include <linux/init.h> 1869a80d3fSPaul Mackerras #include <linux/spinlock.h> 1969a80d3fSPaul Mackerras #include <linux/cache.h> 2069a80d3fSPaul Mackerras #include <linux/err.h> 21edbaa603SKay Sievers #include <linux/device.h> 2269a80d3fSPaul Mackerras #include <linux/cpu.h> 2365fddcfcSMike Rapoport #include <linux/pgtable.h> 2469a80d3fSPaul Mackerras 2569a80d3fSPaul Mackerras #include <asm/ptrace.h> 2660063497SArun Sharma #include <linux/atomic.h> 2769a80d3fSPaul Mackerras #include <asm/irq.h> 2869a80d3fSPaul Mackerras #include <asm/page.h> 2969a80d3fSPaul Mackerras #include <asm/io.h> 3069a80d3fSPaul Mackerras #include <asm/prom.h> 3169a80d3fSPaul Mackerras #include <asm/smp.h> 3269a80d3fSPaul Mackerras #include <asm/paca.h> 3369a80d3fSPaul Mackerras #include <asm/machdep.h> 3469a80d3fSPaul Mackerras #include <asm/cputable.h> 3569a80d3fSPaul Mackerras #include <asm/firmware.h> 3669a80d3fSPaul Mackerras #include <asm/rtas.h> 37271c3f35SPaul Mackerras #include <asm/vdso_datapage.h> 388d089085SBenjamin Herrenschmidt #include <asm/cputhreads.h> 390b05ac6eSBenjamin Herrenschmidt #include <asm/xics.h> 40eac1e731SCédric Le Goater #include <asm/xive.h> 41e5e84f0aSIan Munsie #include <asm/dbell.h> 42212bebb4SDeepthi Dharwar #include <asm/plpar_wrappers.h> 432751b628SAnton Blanchard #include <asm/code-patching.h> 444edaac51SSukadev Bhattiprolu #include <asm/svm.h> 4569a80d3fSPaul Mackerras 468feaeca2SMichael Ellerman #include "pseries.h" 473aa565f5SGautham R Shenoy #include "offline_states.h" 48a1218720SMichael Ellerman 4969a80d3fSPaul Mackerras 5069a80d3fSPaul Mackerras /* 516a75a6b8SMilton Miller * The Primary thread of each non-boot processor was started from the OF client 526a75a6b8SMilton Miller * interface by prom_hold_cpus and is spinning on secondary_hold_spinloop. 5369a80d3fSPaul Mackerras */ 54af831e1eSAnton Blanchard static cpumask_var_t of_spin_mask; 5569a80d3fSPaul Mackerras 56f8b67691SMichael Neuling /* Query where a cpu is now. Return codes #defined in plpar_wrappers.h */ 57f8b67691SMichael Neuling int smp_query_cpu_stopped(unsigned int pcpu) 58f8b67691SMichael Neuling { 59f8b67691SMichael Neuling int cpu_status, status; 60f8b67691SMichael Neuling int qcss_tok = rtas_token("query-cpu-stopped-state"); 61f8b67691SMichael Neuling 62f8b67691SMichael Neuling if (qcss_tok == RTAS_UNKNOWN_SERVICE) { 632d86938aSMilton Miller printk_once(KERN_INFO 642d86938aSMilton Miller "Firmware doesn't support query-cpu-stopped-state\n"); 65f8b67691SMichael Neuling return QCSS_HARDWARE_ERROR; 66f8b67691SMichael Neuling } 67f8b67691SMichael Neuling 68f8b67691SMichael Neuling status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); 69f8b67691SMichael Neuling if (status != 0) { 70f8b67691SMichael Neuling printk(KERN_ERR 71f8b67691SMichael Neuling "RTAS query-cpu-stopped-state failed: %i\n", status); 72f8b67691SMichael Neuling return status; 73f8b67691SMichael Neuling } 74f8b67691SMichael Neuling 75f8b67691SMichael Neuling return cpu_status; 76f8b67691SMichael Neuling } 77f8b67691SMichael Neuling 7869a80d3fSPaul Mackerras /** 7969a80d3fSPaul Mackerras * smp_startup_cpu() - start the given cpu 8069a80d3fSPaul Mackerras * 8169a80d3fSPaul Mackerras * At boot time, there is nothing to do for primary threads which were 8269a80d3fSPaul Mackerras * started from Open Firmware. For anything else, call RTAS with the 8369a80d3fSPaul Mackerras * appropriate start location. 8469a80d3fSPaul Mackerras * 8569a80d3fSPaul Mackerras * Returns: 8669a80d3fSPaul Mackerras * 0 - failure 8769a80d3fSPaul Mackerras * 1 - success 8869a80d3fSPaul Mackerras */ 89cad5cef6SGreg Kroah-Hartman static inline int smp_startup_cpu(unsigned int lcpu) 9069a80d3fSPaul Mackerras { 9169a80d3fSPaul Mackerras int status; 922751b628SAnton Blanchard unsigned long start_here = 932751b628SAnton Blanchard __pa(ppc_function_entry(generic_secondary_smp_init)); 9469a80d3fSPaul Mackerras unsigned int pcpu; 9569a80d3fSPaul Mackerras int start_cpu; 9669a80d3fSPaul Mackerras 97af831e1eSAnton Blanchard if (cpumask_test_cpu(lcpu, of_spin_mask)) 9869a80d3fSPaul Mackerras /* Already started by OF and sitting in spin loop */ 9969a80d3fSPaul Mackerras return 1; 10069a80d3fSPaul Mackerras 10169a80d3fSPaul Mackerras pcpu = get_hard_smp_processor_id(lcpu); 10269a80d3fSPaul Mackerras 103aef40e87SMichael Neuling /* Check to see if the CPU out of FW already for kexec */ 104aef40e87SMichael Neuling if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){ 105af831e1eSAnton Blanchard cpumask_set_cpu(lcpu, of_spin_mask); 106aef40e87SMichael Neuling return 1; 107aef40e87SMichael Neuling } 108aef40e87SMichael Neuling 10969a80d3fSPaul Mackerras /* Fixup atomic count: it exited inside IRQ handler. */ 110d2e60075SNicholas Piggin task_thread_info(paca_ptrs[lcpu]->__current)->preempt_count = 0; 111c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1123aa565f5SGautham R Shenoy if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE) 1133aa565f5SGautham R Shenoy goto out; 114c60e65d7SMatt Evans #endif 11569a80d3fSPaul Mackerras /* 11669a80d3fSPaul Mackerras * If the RTAS start-cpu token does not exist then presume the 11769a80d3fSPaul Mackerras * cpu is already spinning. 11869a80d3fSPaul Mackerras */ 11969a80d3fSPaul Mackerras start_cpu = rtas_token("start-cpu"); 12069a80d3fSPaul Mackerras if (start_cpu == RTAS_UNKNOWN_SERVICE) 12169a80d3fSPaul Mackerras return 1; 12269a80d3fSPaul Mackerras 123496b7a51SMichael Ellerman status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, pcpu); 12469a80d3fSPaul Mackerras if (status != 0) { 12569a80d3fSPaul Mackerras printk(KERN_ERR "start-cpu failed: %i\n", status); 12669a80d3fSPaul Mackerras return 0; 12769a80d3fSPaul Mackerras } 12869a80d3fSPaul Mackerras 129c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1303aa565f5SGautham R Shenoy out: 131c60e65d7SMatt Evans #endif 13269a80d3fSPaul Mackerras return 1; 13369a80d3fSPaul Mackerras } 13469a80d3fSPaul Mackerras 13586425bedSRashmica Gupta static void smp_setup_cpu(int cpu) 13669a80d3fSPaul Mackerras { 137eac1e731SCédric Le Goater if (xive_enabled()) 138eac1e731SCédric Le Goater xive_smp_setup_cpu(); 139eac1e731SCédric Le Goater else if (cpu != boot_cpuid) 14069a80d3fSPaul Mackerras xics_setup_cpu(); 14169a80d3fSPaul Mackerras 14269a80d3fSPaul Mackerras if (firmware_has_feature(FW_FEATURE_SPLPAR)) 14369a80d3fSPaul Mackerras vpa_init(cpu); 14469a80d3fSPaul Mackerras 145af831e1eSAnton Blanchard cpumask_clear_cpu(cpu, of_spin_mask); 146c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1473aa565f5SGautham R Shenoy set_cpu_current_state(cpu, CPU_STATE_ONLINE); 1483aa565f5SGautham R Shenoy set_default_offline_state(cpu); 149c60e65d7SMatt Evans #endif 15069a80d3fSPaul Mackerras } 15169a80d3fSPaul Mackerras 152cad5cef6SGreg Kroah-Hartman static int smp_pSeries_kick_cpu(int nr) 15369a80d3fSPaul Mackerras { 154c642af9cSSantosh Sivaraj if (nr < 0 || nr >= nr_cpu_ids) 155f8d0d5dcSSantosh Sivaraj return -EINVAL; 15669a80d3fSPaul Mackerras 15769a80d3fSPaul Mackerras if (!smp_startup_cpu(nr)) 158de300974SMichael Ellerman return -ENOENT; 15969a80d3fSPaul Mackerras 16069a80d3fSPaul Mackerras /* 16169a80d3fSPaul Mackerras * The processor is currently spinning, waiting for the 16269a80d3fSPaul Mackerras * cpu_start field to become non-zero After we set cpu_start, 16369a80d3fSPaul Mackerras * the processor will continue on to secondary_start 16469a80d3fSPaul Mackerras */ 165d2e60075SNicholas Piggin paca_ptrs[nr]->cpu_start = 1; 166c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1673aa565f5SGautham R Shenoy set_preferred_offline_state(nr, CPU_STATE_ONLINE); 1683aa565f5SGautham R Shenoy 1693aa565f5SGautham R Shenoy if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) { 170c60e65d7SMatt Evans long rc; 171c60e65d7SMatt Evans unsigned long hcpuid; 172c60e65d7SMatt Evans 1733aa565f5SGautham R Shenoy hcpuid = get_hard_smp_processor_id(nr); 1743aa565f5SGautham R Shenoy rc = plpar_hcall_norets(H_PROD, hcpuid); 1753aa565f5SGautham R Shenoy if (rc != H_SUCCESS) 1765a2ad98eSJoe Perches printk(KERN_ERR "Error: Prod to wake up processor %d " 1775a2ad98eSJoe Perches "Ret= %ld\n", nr, rc); 1783aa565f5SGautham R Shenoy } 179c60e65d7SMatt Evans #endif 180de300974SMichael Ellerman 181de300974SMichael Ellerman return 0; 18269a80d3fSPaul Mackerras } 18369a80d3fSPaul Mackerras 184eac1e731SCédric Le Goater static int pseries_smp_prepare_cpu(int cpu) 185eac1e731SCédric Le Goater { 186eac1e731SCédric Le Goater if (xive_enabled()) 187eac1e731SCédric Le Goater return xive_smp_prepare_cpu(cpu); 188eac1e731SCédric Le Goater return 0; 189eac1e731SCédric Le Goater } 190eac1e731SCédric Le Goater 191b866cc21SNicholas Piggin static void smp_pseries_cause_ipi(int cpu) 192e5e84f0aSIan Munsie { 193b866cc21SNicholas Piggin /* POWER9 should not use this handler */ 194b866cc21SNicholas Piggin if (doorbell_try_core_ipi(cpu)) 195b866cc21SNicholas Piggin return; 196b866cc21SNicholas Piggin 197b866cc21SNicholas Piggin icp_ops->cause_ipi(cpu); 198e5e84f0aSIan Munsie } 199e5e84f0aSIan Munsie 200102c05e8SNicholas Piggin static int pseries_cause_nmi_ipi(int cpu) 201102c05e8SNicholas Piggin { 202102c05e8SNicholas Piggin int hwcpu; 203102c05e8SNicholas Piggin 204102c05e8SNicholas Piggin if (cpu == NMI_IPI_ALL_OTHERS) { 205102c05e8SNicholas Piggin hwcpu = H_SIGNAL_SYS_RESET_ALL_OTHERS; 206102c05e8SNicholas Piggin } else { 207102c05e8SNicholas Piggin if (cpu < 0) { 208102c05e8SNicholas Piggin WARN_ONCE(true, "incorrect cpu parameter %d", cpu); 209102c05e8SNicholas Piggin return 0; 210102c05e8SNicholas Piggin } 211102c05e8SNicholas Piggin 212102c05e8SNicholas Piggin hwcpu = get_hard_smp_processor_id(cpu); 213102c05e8SNicholas Piggin } 214102c05e8SNicholas Piggin 2157c09c186SMichael Ellerman if (plpar_signal_sys_reset(hwcpu) == H_SUCCESS) 216102c05e8SNicholas Piggin return 1; 217102c05e8SNicholas Piggin 218102c05e8SNicholas Piggin return 0; 219102c05e8SNicholas Piggin } 220102c05e8SNicholas Piggin 221eac1e731SCédric Le Goater static __init void pSeries_smp_probe_xics(void) 222e5e84f0aSIan Munsie { 223a7f4ee1fSMichael Ellerman xics_smp_probe(); 224e5e84f0aSIan Munsie 2254edaac51SSukadev Bhattiprolu if (cpu_has_feature(CPU_FTR_DBELL) && !is_secure_guest()) 226b866cc21SNicholas Piggin smp_ops->cause_ipi = smp_pseries_cause_ipi; 227b866cc21SNicholas Piggin else 228b866cc21SNicholas Piggin smp_ops->cause_ipi = icp_ops->cause_ipi; 229e5e84f0aSIan Munsie } 230e5e84f0aSIan Munsie 231eac1e731SCédric Le Goater static __init void pSeries_smp_probe(void) 232eac1e731SCédric Le Goater { 233eac1e731SCédric Le Goater if (xive_enabled()) 234eac1e731SCédric Le Goater /* 235eac1e731SCédric Le Goater * Don't use P9 doorbells when XIVE is enabled. IPIs 236eac1e731SCédric Le Goater * using MMIOs should be faster 237eac1e731SCédric Le Goater */ 238eac1e731SCédric Le Goater xive_smp_probe(); 239eac1e731SCédric Le Goater else 240eac1e731SCédric Le Goater pSeries_smp_probe_xics(); 241eac1e731SCédric Le Goater } 242eac1e731SCédric Le Goater 24386425bedSRashmica Gupta static struct smp_ops_t pseries_smp_ops = { 2449ca980dcSPaul Mackerras .message_pass = NULL, /* Use smp_muxed_ipi_message_pass */ 245e5e84f0aSIan Munsie .cause_ipi = NULL, /* Filled at runtime by pSeries_smp_probe() */ 246102c05e8SNicholas Piggin .cause_nmi_ipi = pseries_cause_nmi_ipi, 247e5e84f0aSIan Munsie .probe = pSeries_smp_probe, 248eac1e731SCédric Le Goater .prepare_cpu = pseries_smp_prepare_cpu, 24969a80d3fSPaul Mackerras .kick_cpu = smp_pSeries_kick_cpu, 25086425bedSRashmica Gupta .setup_cpu = smp_setup_cpu, 25139fd4027SAndy Fleming .cpu_bootable = smp_generic_cpu_bootable, 25269a80d3fSPaul Mackerras }; 25369a80d3fSPaul Mackerras 25469a80d3fSPaul Mackerras /* This is called very early */ 25586425bedSRashmica Gupta void __init smp_init_pseries(void) 25669a80d3fSPaul Mackerras { 25769a80d3fSPaul Mackerras int i; 25869a80d3fSPaul Mackerras 259f7ebf352SMichael Ellerman pr_debug(" -> smp_init_pSeries()\n"); 26086425bedSRashmica Gupta smp_ops = &pseries_smp_ops; 26169a80d3fSPaul Mackerras 262af831e1eSAnton Blanchard alloc_bootmem_cpumask_var(&of_spin_mask); 263af831e1eSAnton Blanchard 264dbe78b40SBenjamin Herrenschmidt /* 265dbe78b40SBenjamin Herrenschmidt * Mark threads which are still spinning in hold loops 266dbe78b40SBenjamin Herrenschmidt * 267dbe78b40SBenjamin Herrenschmidt * We know prom_init will not have started them if RTAS supports 268dbe78b40SBenjamin Herrenschmidt * query-cpu-stopped-state. 269dbe78b40SBenjamin Herrenschmidt */ 270dbe78b40SBenjamin Herrenschmidt if (rtas_token("query-cpu-stopped-state") == RTAS_UNKNOWN_SERVICE) { 27169a80d3fSPaul Mackerras if (cpu_has_feature(CPU_FTR_SMT)) { 27269a80d3fSPaul Mackerras for_each_present_cpu(i) { 2736a75a6b8SMilton Miller if (cpu_thread_in_core(i) == 0) 274af831e1eSAnton Blanchard cpumask_set_cpu(i, of_spin_mask); 27569a80d3fSPaul Mackerras } 276dbe78b40SBenjamin Herrenschmidt } else 277af831e1eSAnton Blanchard cpumask_copy(of_spin_mask, cpu_present_mask); 27869a80d3fSPaul Mackerras 279af831e1eSAnton Blanchard cpumask_clear_cpu(boot_cpuid, of_spin_mask); 280dbe78b40SBenjamin Herrenschmidt } 28169a80d3fSPaul Mackerras 28269a80d3fSPaul Mackerras /* Non-lpar has additional take/give timebase */ 28369a80d3fSPaul Mackerras if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { 284c4007a2fSBenjamin Herrenschmidt smp_ops->give_timebase = rtas_give_timebase; 285c4007a2fSBenjamin Herrenschmidt smp_ops->take_timebase = rtas_take_timebase; 28669a80d3fSPaul Mackerras } 28769a80d3fSPaul Mackerras 288f7ebf352SMichael Ellerman pr_debug(" <- smp_init_pSeries()\n"); 28969a80d3fSPaul Mackerras } 290