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> 4169a80d3fSPaul Mackerras #include <asm/mpic.h> 42271c3f35SPaul Mackerras #include <asm/vdso_datapage.h> 438d089085SBenjamin Herrenschmidt #include <asm/cputhreads.h> 440b05ac6eSBenjamin Herrenschmidt #include <asm/xics.h> 45e5e84f0aSIan Munsie #include <asm/dbell.h> 4669a80d3fSPaul Mackerras 47a1218720SMichael Ellerman #include "plpar_wrappers.h" 488feaeca2SMichael Ellerman #include "pseries.h" 493aa565f5SGautham R Shenoy #include "offline_states.h" 50a1218720SMichael Ellerman 5169a80d3fSPaul Mackerras 5269a80d3fSPaul Mackerras /* 536a75a6b8SMilton Miller * The Primary thread of each non-boot processor was started from the OF client 546a75a6b8SMilton Miller * interface by prom_hold_cpus and is spinning on secondary_hold_spinloop. 5569a80d3fSPaul Mackerras */ 56af831e1eSAnton Blanchard static cpumask_var_t of_spin_mask; 5769a80d3fSPaul Mackerras 58e5e84f0aSIan Munsie /* 59e5e84f0aSIan Munsie * If we multiplex IPI mechanisms, store the appropriate XICS IPI mechanism here 60e5e84f0aSIan Munsie */ 61e5e84f0aSIan Munsie static void (*xics_cause_ipi)(int cpu, unsigned long data); 62e5e84f0aSIan Munsie 63f8b67691SMichael Neuling /* Query where a cpu is now. Return codes #defined in plpar_wrappers.h */ 64f8b67691SMichael Neuling int smp_query_cpu_stopped(unsigned int pcpu) 65f8b67691SMichael Neuling { 66f8b67691SMichael Neuling int cpu_status, status; 67f8b67691SMichael Neuling int qcss_tok = rtas_token("query-cpu-stopped-state"); 68f8b67691SMichael Neuling 69f8b67691SMichael Neuling if (qcss_tok == RTAS_UNKNOWN_SERVICE) { 702d86938aSMilton Miller printk_once(KERN_INFO 712d86938aSMilton Miller "Firmware doesn't support query-cpu-stopped-state\n"); 72f8b67691SMichael Neuling return QCSS_HARDWARE_ERROR; 73f8b67691SMichael Neuling } 74f8b67691SMichael Neuling 75f8b67691SMichael Neuling status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); 76f8b67691SMichael Neuling if (status != 0) { 77f8b67691SMichael Neuling printk(KERN_ERR 78f8b67691SMichael Neuling "RTAS query-cpu-stopped-state failed: %i\n", status); 79f8b67691SMichael Neuling return status; 80f8b67691SMichael Neuling } 81f8b67691SMichael Neuling 82f8b67691SMichael Neuling return cpu_status; 83f8b67691SMichael Neuling } 84f8b67691SMichael Neuling 8569a80d3fSPaul Mackerras /** 8669a80d3fSPaul Mackerras * smp_startup_cpu() - start the given cpu 8769a80d3fSPaul Mackerras * 8869a80d3fSPaul Mackerras * At boot time, there is nothing to do for primary threads which were 8969a80d3fSPaul Mackerras * started from Open Firmware. For anything else, call RTAS with the 9069a80d3fSPaul Mackerras * appropriate start location. 9169a80d3fSPaul Mackerras * 9269a80d3fSPaul Mackerras * Returns: 9369a80d3fSPaul Mackerras * 0 - failure 9469a80d3fSPaul Mackerras * 1 - success 9569a80d3fSPaul Mackerras */ 96cad5cef6SGreg Kroah-Hartman static inline int smp_startup_cpu(unsigned int lcpu) 9769a80d3fSPaul Mackerras { 9869a80d3fSPaul Mackerras int status; 9969a80d3fSPaul Mackerras unsigned long start_here = __pa((u32)*((unsigned long *) 100f39b7a55SOlof Johansson generic_secondary_smp_init)); 10169a80d3fSPaul Mackerras unsigned int pcpu; 10269a80d3fSPaul Mackerras int start_cpu; 10369a80d3fSPaul Mackerras 104af831e1eSAnton Blanchard if (cpumask_test_cpu(lcpu, of_spin_mask)) 10569a80d3fSPaul Mackerras /* Already started by OF and sitting in spin loop */ 10669a80d3fSPaul Mackerras return 1; 10769a80d3fSPaul Mackerras 10869a80d3fSPaul Mackerras pcpu = get_hard_smp_processor_id(lcpu); 10969a80d3fSPaul Mackerras 110aef40e87SMichael Neuling /* Check to see if the CPU out of FW already for kexec */ 111aef40e87SMichael Neuling if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){ 112af831e1eSAnton Blanchard cpumask_set_cpu(lcpu, of_spin_mask); 113aef40e87SMichael Neuling return 1; 114aef40e87SMichael Neuling } 115aef40e87SMichael Neuling 11669a80d3fSPaul Mackerras /* Fixup atomic count: it exited inside IRQ handler. */ 117b5e2fc1cSAl Viro task_thread_info(paca[lcpu].__current)->preempt_count = 0; 118c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1193aa565f5SGautham R Shenoy if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE) 1203aa565f5SGautham R Shenoy goto out; 121c60e65d7SMatt Evans #endif 12269a80d3fSPaul Mackerras /* 12369a80d3fSPaul Mackerras * If the RTAS start-cpu token does not exist then presume the 12469a80d3fSPaul Mackerras * cpu is already spinning. 12569a80d3fSPaul Mackerras */ 12669a80d3fSPaul Mackerras start_cpu = rtas_token("start-cpu"); 12769a80d3fSPaul Mackerras if (start_cpu == RTAS_UNKNOWN_SERVICE) 12869a80d3fSPaul Mackerras return 1; 12969a80d3fSPaul Mackerras 130496b7a51SMichael Ellerman status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, pcpu); 13169a80d3fSPaul Mackerras if (status != 0) { 13269a80d3fSPaul Mackerras printk(KERN_ERR "start-cpu failed: %i\n", status); 13369a80d3fSPaul Mackerras return 0; 13469a80d3fSPaul Mackerras } 13569a80d3fSPaul Mackerras 136c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1373aa565f5SGautham R Shenoy out: 138c60e65d7SMatt Evans #endif 13969a80d3fSPaul Mackerras return 1; 14069a80d3fSPaul Mackerras } 14169a80d3fSPaul Mackerras 142cad5cef6SGreg Kroah-Hartman static void smp_xics_setup_cpu(int cpu) 14369a80d3fSPaul Mackerras { 14469a80d3fSPaul Mackerras if (cpu != boot_cpuid) 14569a80d3fSPaul Mackerras xics_setup_cpu(); 146e5e84f0aSIan Munsie if (cpu_has_feature(CPU_FTR_DBELL)) 147e5e84f0aSIan Munsie doorbell_setup_this_cpu(); 14869a80d3fSPaul Mackerras 14969a80d3fSPaul Mackerras if (firmware_has_feature(FW_FEATURE_SPLPAR)) 15069a80d3fSPaul Mackerras vpa_init(cpu); 15169a80d3fSPaul Mackerras 152af831e1eSAnton Blanchard cpumask_clear_cpu(cpu, of_spin_mask); 153c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1543aa565f5SGautham R Shenoy set_cpu_current_state(cpu, CPU_STATE_ONLINE); 1553aa565f5SGautham R Shenoy set_default_offline_state(cpu); 156c60e65d7SMatt Evans #endif 15769a80d3fSPaul Mackerras } 15869a80d3fSPaul Mackerras 159cad5cef6SGreg Kroah-Hartman static int smp_pSeries_kick_cpu(int nr) 16069a80d3fSPaul Mackerras { 16169a80d3fSPaul Mackerras BUG_ON(nr < 0 || nr >= NR_CPUS); 16269a80d3fSPaul Mackerras 16369a80d3fSPaul Mackerras if (!smp_startup_cpu(nr)) 164de300974SMichael Ellerman return -ENOENT; 16569a80d3fSPaul Mackerras 16669a80d3fSPaul Mackerras /* 16769a80d3fSPaul Mackerras * The processor is currently spinning, waiting for the 16869a80d3fSPaul Mackerras * cpu_start field to become non-zero After we set cpu_start, 16969a80d3fSPaul Mackerras * the processor will continue on to secondary_start 17069a80d3fSPaul Mackerras */ 17169a80d3fSPaul Mackerras paca[nr].cpu_start = 1; 172c60e65d7SMatt Evans #ifdef CONFIG_HOTPLUG_CPU 1733aa565f5SGautham R Shenoy set_preferred_offline_state(nr, CPU_STATE_ONLINE); 1743aa565f5SGautham R Shenoy 1753aa565f5SGautham R Shenoy if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) { 176c60e65d7SMatt Evans long rc; 177c60e65d7SMatt Evans unsigned long hcpuid; 178c60e65d7SMatt Evans 1793aa565f5SGautham R Shenoy hcpuid = get_hard_smp_processor_id(nr); 1803aa565f5SGautham R Shenoy rc = plpar_hcall_norets(H_PROD, hcpuid); 1813aa565f5SGautham R Shenoy if (rc != H_SUCCESS) 1825a2ad98eSJoe Perches printk(KERN_ERR "Error: Prod to wake up processor %d " 1835a2ad98eSJoe Perches "Ret= %ld\n", nr, rc); 1843aa565f5SGautham R Shenoy } 185c60e65d7SMatt Evans #endif 186de300974SMichael Ellerman 187de300974SMichael Ellerman return 0; 18869a80d3fSPaul Mackerras } 18969a80d3fSPaul Mackerras 190e5e84f0aSIan Munsie /* Only used on systems that support multiple IPI mechanisms */ 191e5e84f0aSIan Munsie static void pSeries_cause_ipi_mux(int cpu, unsigned long data) 192e5e84f0aSIan Munsie { 193e5e84f0aSIan Munsie if (cpumask_test_cpu(cpu, cpu_sibling_mask(smp_processor_id()))) 194e5e84f0aSIan Munsie doorbell_cause_ipi(cpu, data); 195e5e84f0aSIan Munsie else 196e5e84f0aSIan Munsie xics_cause_ipi(cpu, data); 197e5e84f0aSIan Munsie } 198e5e84f0aSIan Munsie 199e5e84f0aSIan Munsie static __init int pSeries_smp_probe(void) 200e5e84f0aSIan Munsie { 201e5e84f0aSIan Munsie int ret = xics_smp_probe(); 202e5e84f0aSIan Munsie 203e5e84f0aSIan Munsie if (cpu_has_feature(CPU_FTR_DBELL)) { 204e5e84f0aSIan Munsie xics_cause_ipi = smp_ops->cause_ipi; 205e5e84f0aSIan Munsie smp_ops->cause_ipi = pSeries_cause_ipi_mux; 206e5e84f0aSIan Munsie } 207e5e84f0aSIan Munsie 208e5e84f0aSIan Munsie return ret; 209e5e84f0aSIan Munsie } 210e5e84f0aSIan Munsie 21169a80d3fSPaul Mackerras static struct smp_ops_t pSeries_mpic_smp_ops = { 21269a80d3fSPaul Mackerras .message_pass = smp_mpic_message_pass, 21369a80d3fSPaul Mackerras .probe = smp_mpic_probe, 21469a80d3fSPaul Mackerras .kick_cpu = smp_pSeries_kick_cpu, 21569a80d3fSPaul Mackerras .setup_cpu = smp_mpic_setup_cpu, 21669a80d3fSPaul Mackerras }; 2170b05ac6eSBenjamin Herrenschmidt 21869a80d3fSPaul Mackerras static struct smp_ops_t pSeries_xics_smp_ops = { 2199ca980dcSPaul Mackerras .message_pass = NULL, /* Use smp_muxed_ipi_message_pass */ 220e5e84f0aSIan Munsie .cause_ipi = NULL, /* Filled at runtime by pSeries_smp_probe() */ 221e5e84f0aSIan Munsie .probe = pSeries_smp_probe, 22269a80d3fSPaul Mackerras .kick_cpu = smp_pSeries_kick_cpu, 22369a80d3fSPaul Mackerras .setup_cpu = smp_xics_setup_cpu, 22439fd4027SAndy Fleming .cpu_bootable = smp_generic_cpu_bootable, 22569a80d3fSPaul Mackerras }; 22669a80d3fSPaul Mackerras 22769a80d3fSPaul Mackerras /* This is called very early */ 2280ebfff14SBenjamin Herrenschmidt static void __init smp_init_pseries(void) 22969a80d3fSPaul Mackerras { 23069a80d3fSPaul Mackerras int i; 23169a80d3fSPaul Mackerras 232f7ebf352SMichael Ellerman pr_debug(" -> smp_init_pSeries()\n"); 23369a80d3fSPaul Mackerras 234af831e1eSAnton Blanchard alloc_bootmem_cpumask_var(&of_spin_mask); 235af831e1eSAnton Blanchard 23669a80d3fSPaul Mackerras /* Mark threads which are still spinning in hold loops. */ 23769a80d3fSPaul Mackerras if (cpu_has_feature(CPU_FTR_SMT)) { 23869a80d3fSPaul Mackerras for_each_present_cpu(i) { 2396a75a6b8SMilton Miller if (cpu_thread_in_core(i) == 0) 240af831e1eSAnton Blanchard cpumask_set_cpu(i, of_spin_mask); 24169a80d3fSPaul Mackerras } 24269a80d3fSPaul Mackerras } else { 243af831e1eSAnton Blanchard cpumask_copy(of_spin_mask, cpu_present_mask); 24469a80d3fSPaul Mackerras } 24569a80d3fSPaul Mackerras 246af831e1eSAnton Blanchard cpumask_clear_cpu(boot_cpuid, of_spin_mask); 24769a80d3fSPaul Mackerras 24869a80d3fSPaul Mackerras /* Non-lpar has additional take/give timebase */ 24969a80d3fSPaul Mackerras if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { 250c4007a2fSBenjamin Herrenschmidt smp_ops->give_timebase = rtas_give_timebase; 251c4007a2fSBenjamin Herrenschmidt smp_ops->take_timebase = rtas_take_timebase; 25269a80d3fSPaul Mackerras } 25369a80d3fSPaul Mackerras 254f7ebf352SMichael Ellerman pr_debug(" <- smp_init_pSeries()\n"); 25569a80d3fSPaul Mackerras } 25669a80d3fSPaul Mackerras 2570ebfff14SBenjamin Herrenschmidt void __init smp_init_pseries_mpic(void) 2580ebfff14SBenjamin Herrenschmidt { 2590ebfff14SBenjamin Herrenschmidt smp_ops = &pSeries_mpic_smp_ops; 2600ebfff14SBenjamin Herrenschmidt 2610ebfff14SBenjamin Herrenschmidt smp_init_pseries(); 2620ebfff14SBenjamin Herrenschmidt } 2630ebfff14SBenjamin Herrenschmidt 2640ebfff14SBenjamin Herrenschmidt void __init smp_init_pseries_xics(void) 2650ebfff14SBenjamin Herrenschmidt { 2660ebfff14SBenjamin Herrenschmidt smp_ops = &pSeries_xics_smp_ops; 2670ebfff14SBenjamin Herrenschmidt 2680ebfff14SBenjamin Herrenschmidt smp_init_pseries(); 2690ebfff14SBenjamin Herrenschmidt } 270