diff options
Diffstat (limited to 'arch/mips/kernel/smp-cmp.c')
| -rw-r--r-- | arch/mips/kernel/smp-cmp.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/arch/mips/kernel/smp-cmp.c b/arch/mips/kernel/smp-cmp.c new file mode 100644 index 00000000000..ca476c4f62a --- /dev/null +++ b/arch/mips/kernel/smp-cmp.c @@ -0,0 +1,265 @@ +/* + * This program is free software; you can distribute it and/or modify it + * under the terms of the GNU General Public License (Version 2) as + * published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA. + * + * Copyright (C) 2007 MIPS Technologies, Inc. + * Chris Dearman (chris@mips.com) + */ + +#undef DEBUG + +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/cpumask.h> +#include <linux/interrupt.h> +#include <linux/compiler.h> + +#include <asm/atomic.h> +#include <asm/cacheflush.h> +#include <asm/cpu.h> +#include <asm/processor.h> +#include <asm/system.h> +#include <asm/hardirq.h> +#include <asm/mmu_context.h> +#include <asm/smp.h> +#include <asm/time.h> +#include <asm/mipsregs.h> +#include <asm/mipsmtregs.h> +#include <asm/mips_mt.h> + +/* + * Crude manipulation of the CPU masks to control which + * which CPU's are brought online during initialisation + * + * Beware... this needs to be called after CPU discovery + * but before CPU bringup + */ +static int __init allowcpus(char *str) +{ + cpumask_t cpu_allow_map; + char buf[256]; + int len; + + cpus_clear(cpu_allow_map); + if (cpulist_parse(str, cpu_allow_map) == 0) { + cpu_set(0, cpu_allow_map); + cpus_and(cpu_possible_map, cpu_possible_map, cpu_allow_map); + len = cpulist_scnprintf(buf, sizeof(buf)-1, cpu_possible_map); + buf[len] = '\0'; + pr_debug("Allowable CPUs: %s\n", buf); + return 1; + } else + return 0; +} +__setup("allowcpus=", allowcpus); + +static void ipi_call_function(unsigned int cpu) +{ + unsigned int action = 0; + + pr_debug("CPU%d: %s cpu %d status %08x\n", + smp_processor_id(), __func__, cpu, read_c0_status()); + + switch (cpu) { + case 0: + action = GIC_IPI_EXT_INTR_CALLFNC_VPE0; + break; + case 1: + action = GIC_IPI_EXT_INTR_CALLFNC_VPE1; + break; + case 2: + action = GIC_IPI_EXT_INTR_CALLFNC_VPE2; + break; + case 3: + action = GIC_IPI_EXT_INTR_CALLFNC_VPE3; + break; + } + gic_send_ipi(action); +} + + +static void ipi_resched(unsigned int cpu) +{ + unsigned int action = 0; + + pr_debug("CPU%d: %s cpu %d status %08x\n", + smp_processor_id(), __func__, cpu, read_c0_status()); + + switch (cpu) { + case 0: + action = GIC_IPI_EXT_INTR_RESCHED_VPE0; + break; + case 1: + action = GIC_IPI_EXT_INTR_RESCHED_VPE1; + break; + case 2: + action = GIC_IPI_EXT_INTR_RESCHED_VPE2; + break; + case 3: + action = GIC_IPI_EXT_INTR_RESCHED_VPE3; + break; + } + gic_send_ipi(action); +} + +/* + * FIXME: This isn't restricted to CMP + * The SMVP kernel could use GIC interrupts if available + */ +void cmp_send_ipi_single(int cpu, unsigned int action) +{ + unsigned long flags; + + local_irq_save(flags); + + switch (action) { + case SMP_CALL_FUNCTION: + ipi_call_function(cpu); + break; + + case SMP_RESCHEDULE_YOURSELF: + ipi_resched(cpu); + break; + } + + local_irq_restore(flags); +} + +static void cmp_send_ipi_mask(cpumask_t mask, unsigned int action) +{ + unsigned int i; + + for_each_cpu_mask(i, mask) + cmp_send_ipi_single(i, action); +} + +static void cmp_init_secondary(void) +{ + struct cpuinfo_mips *c = ¤t_cpu_data; + + /* Assume GIC is present */ + change_c0_status(ST0_IM, STATUSF_IP3 | STATUSF_IP4 | STATUSF_IP6 | + STATUSF_IP7); + + /* Enable per-cpu interrupts: platform specific */ + + c->core = (read_c0_ebase() >> 1) & 0xff; +#if defined(CONFIG_MIPS_MT_SMP) || defined(CONFIG_MIPS_MT_SMTC) + c->vpe_id = (read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) & TCBIND_CURVPE; +#endif +#ifdef CONFIG_MIPS_MT_SMTC + c->tc_id = (read_c0_tcbind() >> TCBIND_CURTC_SHIFT) & TCBIND_CURTC; +#endif +} + +static void cmp_smp_finish(void) +{ + pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__); + + /* CDFIXME: remove this? */ + write_c0_compare(read_c0_count() + (8 * mips_hpt_frequency / HZ)); + +#ifdef CONFIG_MIPS_MT_FPAFF + /* If we have an FPU, enroll ourselves in the FPU-full mask */ + if (cpu_has_fpu) + cpu_set(smp_processor_id(), mt_fpu_cpumask); +#endif /* CONFIG_MIPS_MT_FPAFF */ + + local_irq_enable(); +} + +static void cmp_cpus_done(void) +{ + pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__); +} + +/* + * Setup the PC, SP, and GP of a secondary processor and start it running + * smp_bootstrap is the place to resume from + * __KSTK_TOS(idle) is apparently the stack pointer + * (unsigned long)idle->thread_info the gp + */ +static void cmp_boot_secondary(int cpu, struct task_struct *idle) +{ + struct thread_info *gp = task_thread_info(idle); + unsigned long sp = __KSTK_TOS(idle); + unsigned long pc = (unsigned long)&smp_bootstrap; + unsigned long a0 = 0; + + pr_debug("SMPCMP: CPU%d: %s cpu %d\n", smp_processor_id(), + __func__, cpu); + +#if 0 + /* Needed? */ + flush_icache_range((unsigned long)gp, + (unsigned long)(gp + sizeof(struct thread_info))); +#endif + + amon_cpu_start(cpu, pc, sp, gp, a0); +} + +/* + * Common setup before any secondaries are started + */ +void __init cmp_smp_setup(void) +{ + int i; + int ncpu = 0; + + pr_debug("SMPCMP: CPU%d: %s\n", smp_processor_id(), __func__); + +#ifdef CONFIG_MIPS_MT_FPAFF + /* If we have an FPU, enroll ourselves in the FPU-full mask */ + if (cpu_has_fpu) + cpu_set(0, mt_fpu_cpumask); +#endif /* CONFIG_MIPS_MT_FPAFF */ + + for (i = 1; i < NR_CPUS; i++) { + if (amon_cpu_avail(i)) { + cpu_set(i, phys_cpu_present_map); + __cpu_number_map[i] = ++ncpu; + __cpu_logical_map[ncpu] = i; + } + } + + if (cpu_has_mipsmt) { + unsigned int nvpe, mvpconf0 = read_c0_mvpconf0(); + + nvpe = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1; + smp_num_siblings = nvpe; + } + pr_info("Detected %i available secondary CPU(s)\n", ncpu); +} + +void __init cmp_prepare_cpus(unsigned int max_cpus) +{ + pr_debug("SMPCMP: CPU%d: %s max_cpus=%d\n", + smp_processor_id(), __func__, max_cpus); + + /* + * FIXME: some of these options are per-system, some per-core and + * some per-cpu + */ + mips_mt_set_cpuoptions(); +} + +struct plat_smp_ops cmp_smp_ops = { + .send_ipi_single = cmp_send_ipi_single, + .send_ipi_mask = cmp_send_ipi_mask, + .init_secondary = cmp_init_secondary, + .smp_finish = cmp_smp_finish, + .cpus_done = cmp_cpus_done, + .boot_secondary = cmp_boot_secondary, + .smp_setup = cmp_smp_setup, + .prepare_cpus = cmp_prepare_cpus, +}; |