| /* |
| * SMP support for pSeries machines. |
| * |
| * Dave Engebretsen, Peter Bergner, and |
| * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com |
| * |
| * Plus various changes from other IBM teams... |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| |
| #include <linux/kernel.h> |
| #include <linux/sched.h> |
| #include <linux/smp.h> |
| #include <linux/interrupt.h> |
| #include <linux/delay.h> |
| #include <linux/init.h> |
| #include <linux/spinlock.h> |
| #include <linux/cache.h> |
| #include <linux/err.h> |
| #include <linux/device.h> |
| #include <linux/cpu.h> |
| |
| #include <asm/ptrace.h> |
| #include <linux/atomic.h> |
| #include <asm/irq.h> |
| #include <asm/page.h> |
| #include <asm/pgtable.h> |
| #include <asm/io.h> |
| #include <asm/prom.h> |
| #include <asm/smp.h> |
| #include <asm/paca.h> |
| #include <asm/machdep.h> |
| #include <asm/cputable.h> |
| #include <asm/firmware.h> |
| #include <asm/rtas.h> |
| #include <asm/mpic.h> |
| #include <asm/vdso_datapage.h> |
| #include <asm/cputhreads.h> |
| #include <asm/xics.h> |
| #include <asm/dbell.h> |
| |
| #include "plpar_wrappers.h" |
| #include "pseries.h" |
| #include "offline_states.h" |
| |
| |
| /* |
| * The Primary thread of each non-boot processor was started from the OF client |
| * interface by prom_hold_cpus and is spinning on secondary_hold_spinloop. |
| */ |
| static cpumask_var_t of_spin_mask; |
| |
| /* |
| * If we multiplex IPI mechanisms, store the appropriate XICS IPI mechanism here |
| */ |
| static void (*xics_cause_ipi)(int cpu, unsigned long data); |
| |
| /* Query where a cpu is now. Return codes #defined in plpar_wrappers.h */ |
| int smp_query_cpu_stopped(unsigned int pcpu) |
| { |
| int cpu_status, status; |
| int qcss_tok = rtas_token("query-cpu-stopped-state"); |
| |
| if (qcss_tok == RTAS_UNKNOWN_SERVICE) { |
| printk_once(KERN_INFO |
| "Firmware doesn't support query-cpu-stopped-state\n"); |
| return QCSS_HARDWARE_ERROR; |
| } |
| |
| status = rtas_call(qcss_tok, 1, 2, &cpu_status, pcpu); |
| if (status != 0) { |
| printk(KERN_ERR |
| "RTAS query-cpu-stopped-state failed: %i\n", status); |
| return status; |
| } |
| |
| return cpu_status; |
| } |
| |
| /** |
| * smp_startup_cpu() - start the given cpu |
| * |
| * At boot time, there is nothing to do for primary threads which were |
| * started from Open Firmware. For anything else, call RTAS with the |
| * appropriate start location. |
| * |
| * Returns: |
| * 0 - failure |
| * 1 - success |
| */ |
| static inline int smp_startup_cpu(unsigned int lcpu) |
| { |
| int status; |
| unsigned long start_here = __pa((u32)*((unsigned long *) |
| generic_secondary_smp_init)); |
| unsigned int pcpu; |
| int start_cpu; |
| |
| if (cpumask_test_cpu(lcpu, of_spin_mask)) |
| /* Already started by OF and sitting in spin loop */ |
| return 1; |
| |
| pcpu = get_hard_smp_processor_id(lcpu); |
| |
| /* Check to see if the CPU out of FW already for kexec */ |
| if (smp_query_cpu_stopped(pcpu) == QCSS_NOT_STOPPED){ |
| cpumask_set_cpu(lcpu, of_spin_mask); |
| return 1; |
| } |
| |
| /* Fixup atomic count: it exited inside IRQ handler. */ |
| task_thread_info(paca[lcpu].__current)->preempt_count = 0; |
| #ifdef CONFIG_HOTPLUG_CPU |
| if (get_cpu_current_state(lcpu) == CPU_STATE_INACTIVE) |
| goto out; |
| #endif |
| /* |
| * If the RTAS start-cpu token does not exist then presume the |
| * cpu is already spinning. |
| */ |
| start_cpu = rtas_token("start-cpu"); |
| if (start_cpu == RTAS_UNKNOWN_SERVICE) |
| return 1; |
| |
| status = rtas_call(start_cpu, 3, 1, NULL, pcpu, start_here, pcpu); |
| if (status != 0) { |
| printk(KERN_ERR "start-cpu failed: %i\n", status); |
| return 0; |
| } |
| |
| #ifdef CONFIG_HOTPLUG_CPU |
| out: |
| #endif |
| return 1; |
| } |
| |
| static void smp_xics_setup_cpu(int cpu) |
| { |
| if (cpu != boot_cpuid) |
| xics_setup_cpu(); |
| if (cpu_has_feature(CPU_FTR_DBELL)) |
| doorbell_setup_this_cpu(); |
| |
| if (firmware_has_feature(FW_FEATURE_SPLPAR)) |
| vpa_init(cpu); |
| |
| cpumask_clear_cpu(cpu, of_spin_mask); |
| #ifdef CONFIG_HOTPLUG_CPU |
| set_cpu_current_state(cpu, CPU_STATE_ONLINE); |
| set_default_offline_state(cpu); |
| #endif |
| } |
| |
| static int smp_pSeries_kick_cpu(int nr) |
| { |
| BUG_ON(nr < 0 || nr >= NR_CPUS); |
| |
| if (!smp_startup_cpu(nr)) |
| return -ENOENT; |
| |
| /* |
| * The processor is currently spinning, waiting for the |
| * cpu_start field to become non-zero After we set cpu_start, |
| * the processor will continue on to secondary_start |
| */ |
| paca[nr].cpu_start = 1; |
| #ifdef CONFIG_HOTPLUG_CPU |
| set_preferred_offline_state(nr, CPU_STATE_ONLINE); |
| |
| if (get_cpu_current_state(nr) == CPU_STATE_INACTIVE) { |
| long rc; |
| unsigned long hcpuid; |
| |
| hcpuid = get_hard_smp_processor_id(nr); |
| rc = plpar_hcall_norets(H_PROD, hcpuid); |
| if (rc != H_SUCCESS) |
| printk(KERN_ERR "Error: Prod to wake up processor %d " |
| "Ret= %ld\n", nr, rc); |
| } |
| #endif |
| |
| return 0; |
| } |
| |
| static int smp_pSeries_cpu_bootable(unsigned int nr) |
| { |
| /* Special case - we inhibit secondary thread startup |
| * during boot if the user requests it. |
| */ |
| if (system_state == SYSTEM_BOOTING && cpu_has_feature(CPU_FTR_SMT)) { |
| if (!smt_enabled_at_boot && cpu_thread_in_core(nr) != 0) |
| return 0; |
| if (smt_enabled_at_boot |
| && cpu_thread_in_core(nr) >= smt_enabled_at_boot) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /* Only used on systems that support multiple IPI mechanisms */ |
| static void pSeries_cause_ipi_mux(int cpu, unsigned long data) |
| { |
| if (cpumask_test_cpu(cpu, cpu_sibling_mask(smp_processor_id()))) |
| doorbell_cause_ipi(cpu, data); |
| else |
| xics_cause_ipi(cpu, data); |
| } |
| |
| static __init int pSeries_smp_probe(void) |
| { |
| int ret = xics_smp_probe(); |
| |
| if (cpu_has_feature(CPU_FTR_DBELL)) { |
| xics_cause_ipi = smp_ops->cause_ipi; |
| smp_ops->cause_ipi = pSeries_cause_ipi_mux; |
| } |
| |
| return ret; |
| } |
| |
| static struct smp_ops_t pSeries_mpic_smp_ops = { |
| .message_pass = smp_mpic_message_pass, |
| .probe = smp_mpic_probe, |
| .kick_cpu = smp_pSeries_kick_cpu, |
| .setup_cpu = smp_mpic_setup_cpu, |
| }; |
| |
| static struct smp_ops_t pSeries_xics_smp_ops = { |
| .message_pass = NULL, /* Use smp_muxed_ipi_message_pass */ |
| .cause_ipi = NULL, /* Filled at runtime by pSeries_smp_probe() */ |
| .probe = pSeries_smp_probe, |
| .kick_cpu = smp_pSeries_kick_cpu, |
| .setup_cpu = smp_xics_setup_cpu, |
| .cpu_bootable = smp_pSeries_cpu_bootable, |
| }; |
| |
| /* This is called very early */ |
| static void __init smp_init_pseries(void) |
| { |
| int i; |
| |
| pr_debug(" -> smp_init_pSeries()\n"); |
| |
| alloc_bootmem_cpumask_var(&of_spin_mask); |
| |
| /* Mark threads which are still spinning in hold loops. */ |
| if (cpu_has_feature(CPU_FTR_SMT)) { |
| for_each_present_cpu(i) { |
| if (cpu_thread_in_core(i) == 0) |
| cpumask_set_cpu(i, of_spin_mask); |
| } |
| } else { |
| cpumask_copy(of_spin_mask, cpu_present_mask); |
| } |
| |
| cpumask_clear_cpu(boot_cpuid, of_spin_mask); |
| |
| /* Non-lpar has additional take/give timebase */ |
| if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) { |
| smp_ops->give_timebase = rtas_give_timebase; |
| smp_ops->take_timebase = rtas_take_timebase; |
| } |
| |
| pr_debug(" <- smp_init_pSeries()\n"); |
| } |
| |
| void __init smp_init_pseries_mpic(void) |
| { |
| smp_ops = &pSeries_mpic_smp_ops; |
| |
| smp_init_pseries(); |
| } |
| |
| void __init smp_init_pseries_xics(void) |
| { |
| smp_ops = &pSeries_xics_smp_ops; |
| |
| smp_init_pseries(); |
| } |