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Diffstat (limited to 'arch/tile/kernel/smp.c')
-rw-r--r-- | arch/tile/kernel/smp.c | 287 |
1 files changed, 0 insertions, 287 deletions
diff --git a/arch/tile/kernel/smp.c b/arch/tile/kernel/smp.c deleted file mode 100644 index 94a62e1197ce..000000000000 --- a/arch/tile/kernel/smp.c +++ /dev/null @@ -1,287 +0,0 @@ -/* - * Copyright 2010 Tilera Corporation. All Rights Reserved. - * - * 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, version 2. - * - * This program is distributed in the hope that it will be useful, but - * WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or - * NON INFRINGEMENT. See the GNU General Public License for - * more details. - * - * TILE SMP support routines. - */ - -#include <linux/smp.h> -#include <linux/interrupt.h> -#include <linux/io.h> -#include <linux/irq.h> -#include <linux/irq_work.h> -#include <linux/module.h> -#include <asm/cacheflush.h> -#include <asm/homecache.h> - -/* - * We write to width and height with a single store in head_NN.S, - * so make the variable aligned to "long". - */ -HV_Topology smp_topology __ro_after_init __aligned(sizeof(long)); -EXPORT_SYMBOL(smp_topology); - -#if CHIP_HAS_IPI() -static unsigned long __iomem *ipi_mappings[NR_CPUS]; -#endif - -/* Does messaging work correctly to the local cpu? */ -bool self_interrupt_ok; - -/* - * Top-level send_IPI*() functions to send messages to other cpus. - */ - -/* Set by smp_send_stop() to avoid recursive panics. */ -static int stopping_cpus; - -static void __send_IPI_many(HV_Recipient *recip, int nrecip, int tag) -{ - int sent = 0; - while (sent < nrecip) { - int rc = hv_send_message(recip, nrecip, - (HV_VirtAddr)&tag, sizeof(tag)); - if (rc < 0) { - if (!stopping_cpus) /* avoid recursive panic */ - panic("hv_send_message returned %d", rc); - break; - } - WARN_ONCE(rc == 0, "hv_send_message() returned zero\n"); - sent += rc; - } -} - -void send_IPI_single(int cpu, int tag) -{ - HV_Recipient recip = { - .y = cpu / smp_width, - .x = cpu % smp_width, - .state = HV_TO_BE_SENT - }; - __send_IPI_many(&recip, 1, tag); -} - -void send_IPI_many(const struct cpumask *mask, int tag) -{ - HV_Recipient recip[NR_CPUS]; - int cpu; - int nrecip = 0; - int my_cpu = smp_processor_id(); - for_each_cpu(cpu, mask) { - HV_Recipient *r; - BUG_ON(cpu == my_cpu); - r = &recip[nrecip++]; - r->y = cpu / smp_width; - r->x = cpu % smp_width; - r->state = HV_TO_BE_SENT; - } - __send_IPI_many(recip, nrecip, tag); -} - -void send_IPI_allbutself(int tag) -{ - struct cpumask mask; - cpumask_copy(&mask, cpu_online_mask); - cpumask_clear_cpu(smp_processor_id(), &mask); - send_IPI_many(&mask, tag); -} - -/* - * Functions related to starting/stopping cpus. - */ - -/* Handler to start the current cpu. */ -static void smp_start_cpu_interrupt(void) -{ - get_irq_regs()->pc = start_cpu_function_addr; -} - -/* Handler to stop the current cpu. */ -static void smp_stop_cpu_interrupt(void) -{ - arch_local_irq_disable_all(); - set_cpu_online(smp_processor_id(), 0); - for (;;) - asm("nap; nop"); -} - -/* This function calls the 'stop' function on all other CPUs in the system. */ -void smp_send_stop(void) -{ - stopping_cpus = 1; - send_IPI_allbutself(MSG_TAG_STOP_CPU); -} - -/* On panic, just wait; we may get an smp_send_stop() later on. */ -void panic_smp_self_stop(void) -{ - while (1) - asm("nap; nop"); -} - -/* - * Dispatch code called from hv_message_intr() for HV_MSG_TILE hv messages. - */ -void evaluate_message(int tag) -{ - switch (tag) { - case MSG_TAG_START_CPU: /* Start up a cpu */ - smp_start_cpu_interrupt(); - break; - - case MSG_TAG_STOP_CPU: /* Sent to shut down slave CPU's */ - smp_stop_cpu_interrupt(); - break; - - case MSG_TAG_CALL_FUNCTION_MANY: /* Call function on cpumask */ - generic_smp_call_function_interrupt(); - break; - - case MSG_TAG_CALL_FUNCTION_SINGLE: /* Call function on one other CPU */ - generic_smp_call_function_single_interrupt(); - break; - - case MSG_TAG_IRQ_WORK: /* Invoke IRQ work */ - irq_work_run(); - break; - - default: - panic("Unknown IPI message tag %d", tag); - break; - } -} - - -/* - * flush_icache_range() code uses smp_call_function(). - */ - -struct ipi_flush { - unsigned long start; - unsigned long end; -}; - -static void ipi_flush_icache_range(void *info) -{ - struct ipi_flush *flush = (struct ipi_flush *) info; - __flush_icache_range(flush->start, flush->end); -} - -void flush_icache_range(unsigned long start, unsigned long end) -{ - struct ipi_flush flush = { start, end }; - - /* If invoked with irqs disabled, we can not issue IPIs. */ - if (irqs_disabled()) - flush_remote(0, HV_FLUSH_EVICT_L1I, NULL, 0, 0, 0, - NULL, NULL, 0); - else { - preempt_disable(); - on_each_cpu(ipi_flush_icache_range, &flush, 1); - preempt_enable(); - } -} -EXPORT_SYMBOL(flush_icache_range); - - -#ifdef CONFIG_IRQ_WORK -void arch_irq_work_raise(void) -{ - if (arch_irq_work_has_interrupt()) - send_IPI_single(smp_processor_id(), MSG_TAG_IRQ_WORK); -} -#endif - - -/* Called when smp_send_reschedule() triggers IRQ_RESCHEDULE. */ -static irqreturn_t handle_reschedule_ipi(int irq, void *token) -{ - __this_cpu_inc(irq_stat.irq_resched_count); - scheduler_ipi(); - - return IRQ_HANDLED; -} - -static struct irqaction resched_action = { - .handler = handle_reschedule_ipi, - .name = "resched", - .dev_id = handle_reschedule_ipi /* unique token */, -}; - -void __init ipi_init(void) -{ - int cpu = smp_processor_id(); - HV_Recipient recip = { .y = cpu_y(cpu), .x = cpu_x(cpu), - .state = HV_TO_BE_SENT }; - int tag = MSG_TAG_CALL_FUNCTION_SINGLE; - - /* - * Test if we can message ourselves for arch_irq_work_raise. - * This functionality is only available in the Tilera hypervisor - * in versions 4.3.4 and following. - */ - if (hv_send_message(&recip, 1, (HV_VirtAddr)&tag, sizeof(tag)) == 1) - self_interrupt_ok = true; - else - pr_warn("Older hypervisor: disabling fast irq_work_raise\n"); - -#if CHIP_HAS_IPI() - /* Map IPI trigger MMIO addresses. */ - for_each_possible_cpu(cpu) { - HV_Coord tile; - HV_PTE pte; - unsigned long offset; - - tile.x = cpu_x(cpu); - tile.y = cpu_y(cpu); - if (hv_get_ipi_pte(tile, KERNEL_PL, &pte) != 0) - panic("Failed to initialize IPI for cpu %d\n", cpu); - - offset = PFN_PHYS(pte_pfn(pte)); - ipi_mappings[cpu] = ioremap_prot(offset, PAGE_SIZE, pte); - } -#endif - - /* Bind handle_reschedule_ipi() to IRQ_RESCHEDULE. */ - tile_irq_activate(IRQ_RESCHEDULE, TILE_IRQ_PERCPU); - BUG_ON(setup_irq(IRQ_RESCHEDULE, &resched_action)); -} - -#if CHIP_HAS_IPI() - -void smp_send_reschedule(int cpu) -{ - WARN_ON(cpu_is_offline(cpu)); - - /* - * We just want to do an MMIO store. The traditional writeq() - * functions aren't really correct here, since they're always - * directed at the PCI shim. For now, just do a raw store, - * casting away the __iomem attribute. - */ - ((unsigned long __force *)ipi_mappings[cpu])[IRQ_RESCHEDULE] = 0; -} - -#else - -void smp_send_reschedule(int cpu) -{ - HV_Coord coord; - - WARN_ON(cpu_is_offline(cpu)); - - coord.y = cpu_y(cpu); - coord.x = cpu_x(cpu); - hv_trigger_ipi(coord, IRQ_RESCHEDULE); -} - -#endif /* CHIP_HAS_IPI() */ |