1 files changed, 543 insertions, 0 deletions

diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
new file mode 100644
index 00000000..ac8f8a43
--- /dev/null
+++ b/arch/blackfin/mach-common/smp.c
@@ -0,0 +1,543 @@
+/*
+ * IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited)
+ *
+ * Copyright 2007-2009 Analog Devices Inc.
+ *                         Philippe Gerum <rpm@xenomai.org>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/cache.h>
+#include <linux/clockchips.h>
+#include <linux/profile.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/cpumask.h>
+#include <linux/seq_file.h>
+#include <linux/irq.h>
+#include <linux/slab.h>
+#include <linux/atomic.h>
+#include <asm/cacheflush.h>
+#include <asm/irq_handler.h>
+#include <asm/mmu_context.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/processor.h>
+#include <asm/ptrace.h>
+#include <asm/cpu.h>
+#include <asm/time.h>
+#include <linux/err.h>
+
+/*
+ * Anomaly notes:
+ * 05000120 - we always define corelock as 32-bit integer in L2
+ */
+struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
+
+#ifdef CONFIG_ICACHE_FLUSH_L1
+unsigned long blackfin_iflush_l1_entry[NR_CPUS];
+#endif
+
+struct blackfin_initial_pda __cpuinitdata initial_pda_coreb;
+
+#define BFIN_IPI_TIMER	      0
+#define BFIN_IPI_RESCHEDULE   1
+#define BFIN_IPI_CALL_FUNC    2
+#define BFIN_IPI_CPU_STOP     3
+
+struct blackfin_flush_data {
+	unsigned long start;
+	unsigned long end;
+};
+
+void *secondary_stack;
+
+
+struct smp_call_struct {
+	void (*func)(void *info);
+	void *info;
+	int wait;
+	cpumask_t *waitmask;
+};
+
+static struct blackfin_flush_data smp_flush_data;
+
+static DEFINE_SPINLOCK(stop_lock);
+
+struct ipi_message {
+	unsigned long type;
+	struct smp_call_struct call_struct;
+};
+
+/* A magic number - stress test shows this is safe for common cases */
+#define BFIN_IPI_MSGQ_LEN 5
+
+/* Simple FIFO buffer, overflow leads to panic */
+struct ipi_message_queue {
+	spinlock_t lock;
+	unsigned long count;
+	unsigned long head; /* head of the queue */
+	struct ipi_message ipi_message[BFIN_IPI_MSGQ_LEN];
+};
+
+static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);
+
+static void ipi_cpu_stop(unsigned int cpu)
+{
+	spin_lock(&stop_lock);
+	printk(KERN_CRIT "CPU%u: stopping\n", cpu);
+	dump_stack();
+	spin_unlock(&stop_lock);
+
+	set_cpu_online(cpu, false);
+
+	local_irq_disable();
+
+	while (1)
+		SSYNC();
+}
+
+static void ipi_flush_icache(void *info)
+{
+	struct blackfin_flush_data *fdata = info;
+
+	/* Invalidate the memory holding the bounds of the flushed region. */
+	blackfin_dcache_invalidate_range((unsigned long)fdata,
+					 (unsigned long)fdata + sizeof(*fdata));
+
+	/* Make sure all write buffers in the data side of the core
+	 * are flushed before trying to invalidate the icache.  This
+	 * needs to be after the data flush and before the icache
+	 * flush so that the SSYNC does the right thing in preventing
+	 * the instruction prefetcher from hitting things in cached
+	 * memory at the wrong time -- it runs much further ahead than
+	 * the pipeline.
+	 */
+	SSYNC();
+
+	/* ipi_flaush_icache is invoked by generic flush_icache_range,
+	 * so call blackfin arch icache flush directly here.
+	 */
+	blackfin_icache_flush_range(fdata->start, fdata->end);
+}
+
+static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
+{
+	int wait;
+	void (*func)(void *info);
+	void *info;
+	func = msg->call_struct.func;
+	info = msg->call_struct.info;
+	wait = msg->call_struct.wait;
+	func(info);
+	if (wait) {
+#ifdef __ARCH_SYNC_CORE_DCACHE
+		/*
+		 * 'wait' usually means synchronization between CPUs.
+		 * Invalidate D cache in case shared data was changed
+		 * by func() to ensure cache coherence.
+		 */
+		resync_core_dcache();
+#endif
+		cpumask_clear_cpu(cpu, msg->call_struct.waitmask);
+	}
+}
+
+/* Use IRQ_SUPPLE_0 to request reschedule.
+ * When returning from interrupt to user space,
+ * there is chance to reschedule */
+static irqreturn_t ipi_handler_int0(int irq, void *dev_instance)
+{
+	unsigned int cpu = smp_processor_id();
+
+	platform_clear_ipi(cpu, IRQ_SUPPLE_0);
+	return IRQ_HANDLED;
+}
+
+DECLARE_PER_CPU(struct clock_event_device, coretmr_events);
+void ipi_timer(void)
+{
+	int cpu = smp_processor_id();
+	struct clock_event_device *evt = &per_cpu(coretmr_events, cpu);
+	evt->event_handler(evt);
+}
+
+static irqreturn_t ipi_handler_int1(int irq, void *dev_instance)
+{
+	struct ipi_message *msg;
+	struct ipi_message_queue *msg_queue;
+	unsigned int cpu = smp_processor_id();
+	unsigned long flags;
+
+	platform_clear_ipi(cpu, IRQ_SUPPLE_1);
+
+	msg_queue = &__get_cpu_var(ipi_msg_queue);
+
+	spin_lock_irqsave(&msg_queue->lock, flags);
+
+	while (msg_queue->count) {
+		msg = &msg_queue->ipi_message[msg_queue->head];
+		switch (msg->type) {
+		case BFIN_IPI_TIMER:
+			ipi_timer();
+			break;
+		case BFIN_IPI_RESCHEDULE:
+			scheduler_ipi();
+			break;
+		case BFIN_IPI_CALL_FUNC:
+			ipi_call_function(cpu, msg);
+			break;
+		case BFIN_IPI_CPU_STOP:
+			ipi_cpu_stop(cpu);
+			break;
+		default:
+			printk(KERN_CRIT "CPU%u: Unknown IPI message 0x%lx\n",
+			       cpu, msg->type);
+			break;
+		}
+		msg_queue->head++;
+		msg_queue->head %= BFIN_IPI_MSGQ_LEN;
+		msg_queue->count--;
+	}
+	spin_unlock_irqrestore(&msg_queue->lock, flags);
+	return IRQ_HANDLED;
+}
+
+static void ipi_queue_init(void)
+{
+	unsigned int cpu;
+	struct ipi_message_queue *msg_queue;
+	for_each_possible_cpu(cpu) {
+		msg_queue = &per_cpu(ipi_msg_queue, cpu);
+		spin_lock_init(&msg_queue->lock);
+		msg_queue->count = 0;
+		msg_queue->head = 0;
+	}
+}
+
+static inline void smp_send_message(cpumask_t callmap, unsigned long type,
+					void (*func) (void *info), void *info, int wait)
+{
+	unsigned int cpu;
+	struct ipi_message_queue *msg_queue;
+	struct ipi_message *msg;
+	unsigned long flags, next_msg;
+	cpumask_t waitmask; /* waitmask is shared by all cpus */
+
+	cpumask_copy(&waitmask, &callmap);
+	for_each_cpu(cpu, &callmap) {
+		msg_queue = &per_cpu(ipi_msg_queue, cpu);
+		spin_lock_irqsave(&msg_queue->lock, flags);
+		if (msg_queue->count < BFIN_IPI_MSGQ_LEN) {
+			next_msg = (msg_queue->head + msg_queue->count)
+					% BFIN_IPI_MSGQ_LEN;
+			msg = &msg_queue->ipi_message[next_msg];
+			msg->type = type;
+			if (type == BFIN_IPI_CALL_FUNC) {
+				msg->call_struct.func = func;
+				msg->call_struct.info = info;
+				msg->call_struct.wait = wait;
+				msg->call_struct.waitmask = &waitmask;
+			}
+			msg_queue->count++;
+		} else
+			panic("IPI message queue overflow\n");
+		spin_unlock_irqrestore(&msg_queue->lock, flags);
+		platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
+	}
+
+	if (wait) {
+		while (!cpumask_empty(&waitmask))
+			blackfin_dcache_invalidate_range(
+				(unsigned long)(&waitmask),
+				(unsigned long)(&waitmask));
+#ifdef __ARCH_SYNC_CORE_DCACHE
+		/*
+		 * Invalidate D cache in case shared data was changed by
+		 * other processors to ensure cache coherence.
+		 */
+		resync_core_dcache();
+#endif
+	}
+}
+
+int smp_call_function(void (*func)(void *info), void *info, int wait)
+{
+	cpumask_t callmap;
+
+	preempt_disable();
+	cpumask_copy(&callmap, cpu_online_mask);
+	cpumask_clear_cpu(smp_processor_id(), &callmap);
+	if (!cpumask_empty(&callmap))
+		smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
+
+	preempt_enable();
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(smp_call_function);
+
+int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
+				int wait)
+{
+	unsigned int cpu = cpuid;
+	cpumask_t callmap;
+
+	if (cpu_is_offline(cpu))
+		return 0;
+	cpumask_clear(&callmap);
+	cpumask_set_cpu(cpu, &callmap);
+
+	smp_send_message(callmap, BFIN_IPI_CALL_FUNC, func, info, wait);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(smp_call_function_single);
+
+void smp_send_reschedule(int cpu)
+{
+	cpumask_t callmap;
+	/* simply trigger an ipi */
+
+	cpumask_clear(&callmap);
+	cpumask_set_cpu(cpu, &callmap);
+
+	smp_send_message(callmap, BFIN_IPI_RESCHEDULE, NULL, NULL, 0);
+
+	return;
+}
+
+void smp_send_msg(const struct cpumask *mask, unsigned long type)
+{
+	smp_send_message(*mask, type, NULL, NULL, 0);
+}
+
+void smp_timer_broadcast(const struct cpumask *mask)
+{
+	smp_send_msg(mask, BFIN_IPI_TIMER);
+}
+
+void smp_send_stop(void)
+{
+	cpumask_t callmap;
+
+	preempt_disable();
+	cpumask_copy(&callmap, cpu_online_mask);
+	cpumask_clear_cpu(smp_processor_id(), &callmap);
+	if (!cpumask_empty(&callmap))
+		smp_send_message(callmap, BFIN_IPI_CPU_STOP, NULL, NULL, 0);
+
+	preempt_enable();
+
+	return;
+}
+
+int __cpuinit __cpu_up(unsigned int cpu)
+{
+	int ret;
+	struct blackfin_cpudata *ci = &per_cpu(cpu_data, cpu);
+	struct task_struct *idle = ci->idle;
+
+	if (idle) {
+		free_task(idle);
+		idle = NULL;
+	}
+
+	if (!idle) {
+		idle = fork_idle(cpu);
+		if (IS_ERR(idle)) {
+			printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
+			return PTR_ERR(idle);
+		}
+		ci->idle = idle;
+	} else {
+		init_idle(idle, cpu);
+	}
+	secondary_stack = task_stack_page(idle) + THREAD_SIZE;
+
+	ret = platform_boot_secondary(cpu, idle);
+
+	secondary_stack = NULL;
+
+	return ret;
+}
+
+static void __cpuinit setup_secondary(unsigned int cpu)
+{
+	unsigned long ilat;
+
+	bfin_write_IMASK(0);
+	CSYNC();
+	ilat = bfin_read_ILAT();
+	CSYNC();
+	bfin_write_ILAT(ilat);
+	CSYNC();
+
+	/* Enable interrupt levels IVG7-15. IARs have been already
+	 * programmed by the boot CPU.  */
+	bfin_irq_flags |= IMASK_IVG15 |
+	    IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
+	    IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
+}
+
+void __cpuinit secondary_start_kernel(void)
+{
+	unsigned int cpu = smp_processor_id();
+	struct mm_struct *mm = &init_mm;
+
+	if (_bfin_swrst & SWRST_DBL_FAULT_B) {
+		printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
+#ifdef CONFIG_DEBUG_DOUBLEFAULT
+		printk(KERN_EMERG " While handling exception (EXCAUSE = %#x) at %pF\n",
+			initial_pda_coreb.seqstat_doublefault & SEQSTAT_EXCAUSE,
+			initial_pda_coreb.retx_doublefault);
+		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n",
+			initial_pda_coreb.dcplb_doublefault_addr);
+		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n",
+			initial_pda_coreb.icplb_doublefault_addr);
+#endif
+		printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
+			initial_pda_coreb.retx);
+	}
+
+	/*
+	 * We want the D-cache to be enabled early, in case the atomic
+	 * support code emulates cache coherence (see
+	 * __ARCH_SYNC_CORE_DCACHE).
+	 */
+	init_exception_vectors();
+
+	local_irq_disable();
+
+	/* Attach the new idle task to the global mm. */
+	atomic_inc(&mm->mm_users);
+	atomic_inc(&mm->mm_count);
+	current->active_mm = mm;
+
+	preempt_disable();
+
+	setup_secondary(cpu);
+
+	platform_secondary_init(cpu);
+
+	/* setup local core timer */
+	bfin_local_timer_setup();
+
+	local_irq_enable();
+
+	bfin_setup_caches(cpu);
+
+	notify_cpu_starting(cpu);
+	/*
+	 * Calibrate loops per jiffy value.
+	 * IRQs need to be enabled here - D-cache can be invalidated
+	 * in timer irq handler, so core B can read correct jiffies.
+	 */
+	calibrate_delay();
+
+	cpu_idle();
+}
+
+void __init smp_prepare_boot_cpu(void)
+{
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+	platform_prepare_cpus(max_cpus);
+	ipi_queue_init();
+	platform_request_ipi(IRQ_SUPPLE_0, ipi_handler_int0);
+	platform_request_ipi(IRQ_SUPPLE_1, ipi_handler_int1);
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+	unsigned long bogosum = 0;
+	unsigned int cpu;
+
+	for_each_online_cpu(cpu)
+		bogosum += loops_per_jiffy;
+
+	printk(KERN_INFO "SMP: Total of %d processors activated "
+	       "(%lu.%02lu BogoMIPS).\n",
+	       num_online_cpus(),
+	       bogosum / (500000/HZ),
+	       (bogosum / (5000/HZ)) % 100);
+}
+
+void smp_icache_flush_range_others(unsigned long start, unsigned long end)
+{
+	smp_flush_data.start = start;
+	smp_flush_data.end = end;
+
+	preempt_disable();
+	if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 1))
+		printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
+	preempt_enable();
+}
+EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
+
+#ifdef __ARCH_SYNC_CORE_ICACHE
+unsigned long icache_invld_count[NR_CPUS];
+void resync_core_icache(void)
+{
+	unsigned int cpu = get_cpu();
+	blackfin_invalidate_entire_icache();
+	icache_invld_count[cpu]++;
+	put_cpu();
+}
+EXPORT_SYMBOL(resync_core_icache);
+#endif
+
+#ifdef __ARCH_SYNC_CORE_DCACHE
+unsigned long dcache_invld_count[NR_CPUS];
+unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
+
+void resync_core_dcache(void)
+{
+	unsigned int cpu = get_cpu();
+	blackfin_invalidate_entire_dcache();
+	dcache_invld_count[cpu]++;
+	put_cpu();
+}
+EXPORT_SYMBOL(resync_core_dcache);
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+int __cpuexit __cpu_disable(void)
+{
+	unsigned int cpu = smp_processor_id();
+
+	if (cpu == 0)
+		return -EPERM;
+
+	set_cpu_online(cpu, false);
+	return 0;
+}
+
+static DECLARE_COMPLETION(cpu_killed);
+
+int __cpuexit __cpu_die(unsigned int cpu)
+{
+	return wait_for_completion_timeout(&cpu_killed, 5000);
+}
+
+void cpu_die(void)
+{
+	complete(&cpu_killed);
+
+	atomic_dec(&init_mm.mm_users);
+	atomic_dec(&init_mm.mm_count);
+
+	local_irq_disable();
+	platform_cpu_die();
+}
+#endif