diff options
Diffstat (limited to 'arch/metag/kernel/smp.c')
-rw-r--r-- | arch/metag/kernel/smp.c | 668 |
1 files changed, 0 insertions, 668 deletions
diff --git a/arch/metag/kernel/smp.c b/arch/metag/kernel/smp.c deleted file mode 100644 index 2dbbb7c..0000000 --- a/arch/metag/kernel/smp.c +++ /dev/null @@ -1,668 +0,0 @@ -/* - * Copyright (C) 2009,2010,2011 Imagination Technologies Ltd. - * - * Copyright (C) 2002 ARM Limited, 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 version 2 as - * published by the Free Software Foundation. - */ -#include <linux/atomic.h> -#include <linux/completion.h> -#include <linux/delay.h> -#include <linux/init.h> -#include <linux/spinlock.h> -#include <linux/sched/mm.h> -#include <linux/sched/hotplug.h> -#include <linux/sched/task_stack.h> -#include <linux/interrupt.h> -#include <linux/cache.h> -#include <linux/profile.h> -#include <linux/errno.h> -#include <linux/mm.h> -#include <linux/err.h> -#include <linux/cpu.h> -#include <linux/smp.h> -#include <linux/seq_file.h> -#include <linux/irq.h> -#include <linux/bootmem.h> - -#include <asm/cacheflush.h> -#include <asm/cachepart.h> -#include <asm/core_reg.h> -#include <asm/cpu.h> -#include <asm/global_lock.h> -#include <asm/metag_mem.h> -#include <asm/mmu_context.h> -#include <asm/pgtable.h> -#include <asm/pgalloc.h> -#include <asm/processor.h> -#include <asm/setup.h> -#include <asm/tlbflush.h> -#include <asm/hwthread.h> -#include <asm/traps.h> - -#define SYSC_DCPART(n) (SYSC_DCPART0 + SYSC_xCPARTn_STRIDE * (n)) -#define SYSC_ICPART(n) (SYSC_ICPART0 + SYSC_xCPARTn_STRIDE * (n)) - -DECLARE_PER_CPU(PTBI, pTBI); - -void *secondary_data_stack; - -/* - * structures for inter-processor calls - * - A collection of single bit ipi messages. - */ -struct ipi_data { - spinlock_t lock; - unsigned long ipi_count; - unsigned long bits; -}; - -static DEFINE_PER_CPU(struct ipi_data, ipi_data) = { - .lock = __SPIN_LOCK_UNLOCKED(ipi_data.lock), -}; - -static DEFINE_SPINLOCK(boot_lock); - -static DECLARE_COMPLETION(cpu_running); - -/* - * "thread" is assumed to be a valid Meta hardware thread ID. - */ -static int boot_secondary(unsigned int thread, struct task_struct *idle) -{ - u32 val; - - /* - * set synchronisation state between this boot processor - * and the secondary one - */ - spin_lock(&boot_lock); - - core_reg_write(TXUPC_ID, 0, thread, (unsigned int)secondary_startup); - core_reg_write(TXUPC_ID, 1, thread, 0); - - /* - * Give the thread privilege (PSTAT) and clear potentially problematic - * bits in the process (namely ISTAT, CBMarker, CBMarkerI, LSM_STEP). - */ - core_reg_write(TXUCT_ID, TXSTATUS_REGNUM, thread, TXSTATUS_PSTAT_BIT); - - /* Clear the minim enable bit. */ - val = core_reg_read(TXUCT_ID, TXPRIVEXT_REGNUM, thread); - core_reg_write(TXUCT_ID, TXPRIVEXT_REGNUM, thread, val & ~0x80); - - /* - * set the ThreadEnable bit (0x1) in the TXENABLE register - * for the specified thread - off it goes! - */ - val = core_reg_read(TXUCT_ID, TXENABLE_REGNUM, thread); - core_reg_write(TXUCT_ID, TXENABLE_REGNUM, thread, val | 0x1); - - /* - * now the secondary core is starting up let it run its - * calibrations, then wait for it to finish - */ - spin_unlock(&boot_lock); - - return 0; -} - -/** - * describe_cachepart_change: describe a change to cache partitions. - * @thread: Hardware thread number. - * @label: Label of cache type, e.g. "dcache" or "icache". - * @sz: Total size of the cache. - * @old: Old cache partition configuration (*CPART* register). - * @new: New cache partition configuration (*CPART* register). - * - * If the cache partition has changed, prints a message to the log describing - * those changes. - */ -static void describe_cachepart_change(unsigned int thread, const char *label, - unsigned int sz, unsigned int old, - unsigned int new) -{ - unsigned int lor1, land1, gor1, gand1; - unsigned int lor2, land2, gor2, gand2; - unsigned int diff = old ^ new; - - if (!diff) - return; - - pr_info("Thread %d: %s partition changed:", thread, label); - if (diff & (SYSC_xCPARTL_OR_BITS | SYSC_xCPARTL_AND_BITS)) { - lor1 = (old & SYSC_xCPARTL_OR_BITS) >> SYSC_xCPARTL_OR_S; - lor2 = (new & SYSC_xCPARTL_OR_BITS) >> SYSC_xCPARTL_OR_S; - land1 = (old & SYSC_xCPARTL_AND_BITS) >> SYSC_xCPARTL_AND_S; - land2 = (new & SYSC_xCPARTL_AND_BITS) >> SYSC_xCPARTL_AND_S; - pr_cont(" L:%#x+%#x->%#x+%#x", - (lor1 * sz) >> 4, - ((land1 + 1) * sz) >> 4, - (lor2 * sz) >> 4, - ((land2 + 1) * sz) >> 4); - } - if (diff & (SYSC_xCPARTG_OR_BITS | SYSC_xCPARTG_AND_BITS)) { - gor1 = (old & SYSC_xCPARTG_OR_BITS) >> SYSC_xCPARTG_OR_S; - gor2 = (new & SYSC_xCPARTG_OR_BITS) >> SYSC_xCPARTG_OR_S; - gand1 = (old & SYSC_xCPARTG_AND_BITS) >> SYSC_xCPARTG_AND_S; - gand2 = (new & SYSC_xCPARTG_AND_BITS) >> SYSC_xCPARTG_AND_S; - pr_cont(" G:%#x+%#x->%#x+%#x", - (gor1 * sz) >> 4, - ((gand1 + 1) * sz) >> 4, - (gor2 * sz) >> 4, - ((gand2 + 1) * sz) >> 4); - } - if (diff & SYSC_CWRMODE_BIT) - pr_cont(" %sWR", - (new & SYSC_CWRMODE_BIT) ? "+" : "-"); - if (diff & SYSC_DCPART_GCON_BIT) - pr_cont(" %sGCOn", - (new & SYSC_DCPART_GCON_BIT) ? "+" : "-"); - pr_cont("\n"); -} - -/** - * setup_smp_cache: ensure cache coherency for new SMP thread. - * @thread: New hardware thread number. - * - * Ensures that coherency is enabled and that the threads share the same cache - * partitions. - */ -static void setup_smp_cache(unsigned int thread) -{ - unsigned int this_thread, lflags; - unsigned int dcsz, dcpart_this, dcpart_old, dcpart_new; - unsigned int icsz, icpart_old, icpart_new; - - /* - * Copy over the current thread's cache partition configuration to the - * new thread so that they share cache partitions. - */ - __global_lock2(lflags); - this_thread = hard_processor_id(); - /* Share dcache partition */ - dcpart_this = metag_in32(SYSC_DCPART(this_thread)); - dcpart_old = metag_in32(SYSC_DCPART(thread)); - dcpart_new = dcpart_this; -#if PAGE_OFFSET < LINGLOBAL_BASE - /* - * For the local data cache to be coherent the threads must also have - * GCOn enabled. - */ - dcpart_new |= SYSC_DCPART_GCON_BIT; - metag_out32(dcpart_new, SYSC_DCPART(this_thread)); -#endif - metag_out32(dcpart_new, SYSC_DCPART(thread)); - /* Share icache partition too */ - icpart_new = metag_in32(SYSC_ICPART(this_thread)); - icpart_old = metag_in32(SYSC_ICPART(thread)); - metag_out32(icpart_new, SYSC_ICPART(thread)); - __global_unlock2(lflags); - - /* - * Log if the cache partitions were altered so the user is aware of any - * potential unintentional cache wastage. - */ - dcsz = get_dcache_size(); - icsz = get_dcache_size(); - describe_cachepart_change(this_thread, "dcache", dcsz, - dcpart_this, dcpart_new); - describe_cachepart_change(thread, "dcache", dcsz, - dcpart_old, dcpart_new); - describe_cachepart_change(thread, "icache", icsz, - icpart_old, icpart_new); -} - -int __cpu_up(unsigned int cpu, struct task_struct *idle) -{ - unsigned int thread = cpu_2_hwthread_id[cpu]; - int ret; - - load_pgd(swapper_pg_dir, thread); - - flush_tlb_all(); - - setup_smp_cache(thread); - - /* - * Tell the secondary CPU where to find its idle thread's stack. - */ - secondary_data_stack = task_stack_page(idle); - - wmb(); - - /* - * Now bring the CPU into our world. - */ - ret = boot_secondary(thread, idle); - if (ret == 0) { - /* - * CPU was successfully started, wait for it - * to come online or time out. - */ - wait_for_completion_timeout(&cpu_running, - msecs_to_jiffies(1000)); - - if (!cpu_online(cpu)) - ret = -EIO; - } - - secondary_data_stack = NULL; - - if (ret) { - pr_crit("CPU%u: processor failed to boot\n", cpu); - - /* - * FIXME: We need to clean up the new idle thread. --rmk - */ - } - - return ret; -} - -#ifdef CONFIG_HOTPLUG_CPU - -/* - * __cpu_disable runs on the processor to be shutdown. - */ -int __cpu_disable(void) -{ - unsigned int cpu = smp_processor_id(); - - /* - * Take this CPU offline. Once we clear this, we can't return, - * and we must not schedule until we're ready to give up the cpu. - */ - set_cpu_online(cpu, false); - - /* - * OK - migrate IRQs away from this CPU - */ - migrate_irqs(); - - /* - * Flush user cache and TLB mappings, and then remove this CPU - * from the vm mask set of all processes. - */ - flush_cache_all(); - local_flush_tlb_all(); - - clear_tasks_mm_cpumask(cpu); - - return 0; -} - -/* - * called on the thread which is asking for a CPU to be shutdown - - * waits until shutdown has completed, or it is timed out. - */ -void __cpu_die(unsigned int cpu) -{ - if (!cpu_wait_death(cpu, 1)) - pr_err("CPU%u: unable to kill\n", cpu); -} - -/* - * Called from the idle thread for the CPU which has been shutdown. - * - * Note that we do not return from this function. If this cpu is - * brought online again it will need to run secondary_startup(). - */ -void cpu_die(void) -{ - local_irq_disable(); - idle_task_exit(); - irq_ctx_exit(smp_processor_id()); - - (void)cpu_report_death(); - - asm ("XOR TXENABLE, D0Re0,D0Re0\n"); -} -#endif /* CONFIG_HOTPLUG_CPU */ - -/* - * Called by both boot and secondaries to move global data into - * per-processor storage. - */ -void smp_store_cpu_info(unsigned int cpuid) -{ - struct cpuinfo_metag *cpu_info = &per_cpu(cpu_data, cpuid); - - cpu_info->loops_per_jiffy = loops_per_jiffy; -} - -/* - * This is the secondary CPU boot entry. We're using this CPUs - * idle thread stack and the global page tables. - */ -asmlinkage void secondary_start_kernel(void) -{ - struct mm_struct *mm = &init_mm; - unsigned int cpu = smp_processor_id(); - - /* - * All kernel threads share the same mm context; grab a - * reference and switch to it. - */ - mmget(mm); - mmgrab(mm); - current->active_mm = mm; - cpumask_set_cpu(cpu, mm_cpumask(mm)); - enter_lazy_tlb(mm, current); - local_flush_tlb_all(); - - /* - * TODO: Some day it might be useful for each Linux CPU to - * have its own TBI structure. That would allow each Linux CPU - * to run different interrupt handlers for the same IRQ - * number. - * - * For now, simply copying the pointer to the boot CPU's TBI - * structure is sufficient because we always want to run the - * same interrupt handler whatever CPU takes the interrupt. - */ - per_cpu(pTBI, cpu) = __TBI(TBID_ISTAT_BIT); - - if (!per_cpu(pTBI, cpu)) - panic("No TBI found!"); - - per_cpu_trap_init(cpu); - irq_ctx_init(cpu); - - preempt_disable(); - - setup_priv(); - - notify_cpu_starting(cpu); - - pr_info("CPU%u (thread %u): Booted secondary processor\n", - cpu, cpu_2_hwthread_id[cpu]); - - calibrate_delay(); - smp_store_cpu_info(cpu); - - /* - * OK, now it's safe to let the boot CPU continue - */ - set_cpu_online(cpu, true); - complete(&cpu_running); - - /* - * Enable local interrupts. - */ - tbi_startup_interrupt(TBID_SIGNUM_TRT); - local_irq_enable(); - - /* - * OK, it's off to the idle thread for us - */ - cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); -} - -void __init smp_cpus_done(unsigned int max_cpus) -{ - int cpu; - unsigned long bogosum = 0; - - for_each_online_cpu(cpu) - bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy; - - pr_info("SMP: Total of %d processors activated (%lu.%02lu BogoMIPS).\n", - num_online_cpus(), - bogosum / (500000/HZ), - (bogosum / (5000/HZ)) % 100); -} - -void __init smp_prepare_cpus(unsigned int max_cpus) -{ - unsigned int cpu = smp_processor_id(); - - init_new_context(current, &init_mm); - current_thread_info()->cpu = cpu; - - smp_store_cpu_info(cpu); - init_cpu_present(cpu_possible_mask); -} - -void __init smp_prepare_boot_cpu(void) -{ - unsigned int cpu = smp_processor_id(); - - per_cpu(pTBI, cpu) = __TBI(TBID_ISTAT_BIT); - - if (!per_cpu(pTBI, cpu)) - panic("No TBI found!"); -} - -static void smp_cross_call(cpumask_t callmap, enum ipi_msg_type msg); - -static void send_ipi_message(const struct cpumask *mask, enum ipi_msg_type msg) -{ - unsigned long flags; - unsigned int cpu; - cpumask_t map; - - cpumask_clear(&map); - local_irq_save(flags); - - for_each_cpu(cpu, mask) { - struct ipi_data *ipi = &per_cpu(ipi_data, cpu); - - spin_lock(&ipi->lock); - - /* - * KICK interrupts are queued in hardware so we'll get - * multiple interrupts if we call smp_cross_call() - * multiple times for one msg. The problem is that we - * only have one bit for each message - we can't queue - * them in software. - * - * The first time through ipi_handler() we'll clear - * the msg bit, having done all the work. But when we - * return we'll get _another_ interrupt (and another, - * and another until we've handled all the queued - * KICKs). Running ipi_handler() when there's no work - * to do is bad because that's how kick handler - * chaining detects who the KICK was intended for. - * See arch/metag/kernel/kick.c for more details. - * - * So only add 'cpu' to 'map' if we haven't already - * queued a KICK interrupt for 'msg'. - */ - if (!(ipi->bits & (1 << msg))) { - ipi->bits |= 1 << msg; - cpumask_set_cpu(cpu, &map); - } - - spin_unlock(&ipi->lock); - } - - /* - * Call the platform specific cross-CPU call function. - */ - smp_cross_call(map, msg); - - local_irq_restore(flags); -} - -void arch_send_call_function_ipi_mask(const struct cpumask *mask) -{ - send_ipi_message(mask, IPI_CALL_FUNC); -} - -void arch_send_call_function_single_ipi(int cpu) -{ - send_ipi_message(cpumask_of(cpu), IPI_CALL_FUNC); -} - -void show_ipi_list(struct seq_file *p) -{ - unsigned int cpu; - - seq_puts(p, "IPI:"); - - for_each_present_cpu(cpu) - seq_printf(p, " %10lu", per_cpu(ipi_data, cpu).ipi_count); - - seq_putc(p, '\n'); -} - -static DEFINE_SPINLOCK(stop_lock); - -/* - * Main handler for inter-processor interrupts - * - * For Meta, the ipimask now only identifies a single - * category of IPI (Bit 1 IPIs have been replaced by a - * different mechanism): - * - * Bit 0 - Inter-processor function call - */ -static int do_IPI(void) -{ - unsigned int cpu = smp_processor_id(); - struct ipi_data *ipi = &per_cpu(ipi_data, cpu); - unsigned long msgs, nextmsg; - int handled = 0; - - ipi->ipi_count++; - - spin_lock(&ipi->lock); - msgs = ipi->bits; - nextmsg = msgs & -msgs; - ipi->bits &= ~nextmsg; - spin_unlock(&ipi->lock); - - if (nextmsg) { - handled = 1; - - nextmsg = ffz(~nextmsg); - switch (nextmsg) { - case IPI_RESCHEDULE: - scheduler_ipi(); - break; - - case IPI_CALL_FUNC: - generic_smp_call_function_interrupt(); - break; - - default: - pr_crit("CPU%u: Unknown IPI message 0x%lx\n", - cpu, nextmsg); - break; - } - } - - return handled; -} - -void smp_send_reschedule(int cpu) -{ - send_ipi_message(cpumask_of(cpu), IPI_RESCHEDULE); -} - -static void stop_this_cpu(void *data) -{ - unsigned int cpu = smp_processor_id(); - - if (system_state <= SYSTEM_RUNNING) { - spin_lock(&stop_lock); - pr_crit("CPU%u: stopping\n", cpu); - dump_stack(); - spin_unlock(&stop_lock); - } - - set_cpu_online(cpu, false); - - local_irq_disable(); - - hard_processor_halt(HALT_OK); -} - -void smp_send_stop(void) -{ - smp_call_function(stop_this_cpu, NULL, 0); -} - -/* - * not supported here - */ -int setup_profiling_timer(unsigned int multiplier) -{ - return -EINVAL; -} - -/* - * We use KICKs for inter-processor interrupts. - * - * For every CPU in "callmap" the IPI data must already have been - * stored in that CPU's "ipi_data" member prior to calling this - * function. - */ -static void kick_raise_softirq(cpumask_t callmap, unsigned int irq) -{ - int cpu; - - for_each_cpu(cpu, &callmap) { - unsigned int thread; - - thread = cpu_2_hwthread_id[cpu]; - - BUG_ON(thread == BAD_HWTHREAD_ID); - - metag_out32(1, T0KICKI + (thread * TnXKICK_STRIDE)); - } -} - -static TBIRES ipi_handler(TBIRES State, int SigNum, int Triggers, - int Inst, PTBI pTBI, int *handled) -{ - *handled = do_IPI(); - - return State; -} - -static struct kick_irq_handler ipi_irq = { - .func = ipi_handler, -}; - -static void smp_cross_call(cpumask_t callmap, enum ipi_msg_type msg) -{ - kick_raise_softirq(callmap, 1); -} - -static inline unsigned int get_core_count(void) -{ - int i; - unsigned int ret = 0; - - for (i = 0; i < CONFIG_NR_CPUS; i++) { - if (core_reg_read(TXUCT_ID, TXENABLE_REGNUM, i)) - ret++; - } - - return ret; -} - -/* - * Initialise the CPU possible map early - this describes the CPUs - * which may be present or become present in the system. - */ -void __init smp_init_cpus(void) -{ - unsigned int i, ncores = get_core_count(); - - /* If no hwthread_map early param was set use default mapping */ - for (i = 0; i < NR_CPUS; i++) - if (cpu_2_hwthread_id[i] == BAD_HWTHREAD_ID) { - cpu_2_hwthread_id[i] = i; - hwthread_id_2_cpu[i] = i; - } - - for (i = 0; i < ncores; i++) - set_cpu_possible(i, true); - - kick_register_func(&ipi_irq); -} |