Initial import

1 files changed, 431 insertions, 0 deletions

diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
new file mode 100644
index 000000000..1c7259597
--- /dev/null
+++ b/arch/blackfin/mach-common/smp.c
@@ -0,0 +1,431 @@
+/*
+ * 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 initial_pda_coreb;
+
+enum ipi_message_type {
+	BFIN_IPI_NONE,
+	BFIN_IPI_TIMER,
+	BFIN_IPI_RESCHEDULE,
+	BFIN_IPI_CALL_FUNC,
+	BFIN_IPI_CPU_STOP,
+};
+
+struct blackfin_flush_data {
+	unsigned long start;
+	unsigned long end;
+};
+
+void *secondary_stack;
+
+static struct blackfin_flush_data smp_flush_data;
+
+static DEFINE_SPINLOCK(stop_lock);
+
+/* 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_data {
+	atomic_t count;
+	atomic_t bits;
+};
+
+static DEFINE_PER_CPU(struct ipi_data, bfin_ipi);
+
+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);
+}
+
+/* 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_data *bfin_ipi_data;
+	unsigned int cpu = smp_processor_id();
+	unsigned long pending;
+	unsigned long msg;
+
+	platform_clear_ipi(cpu, IRQ_SUPPLE_1);
+
+	smp_rmb();
+	bfin_ipi_data = this_cpu_ptr(&bfin_ipi);
+	while ((pending = atomic_xchg(&bfin_ipi_data->bits, 0)) != 0) {
+		msg = 0;
+		do {
+			msg = find_next_bit(&pending, BITS_PER_LONG, msg + 1);
+			switch (msg) {
+			case BFIN_IPI_TIMER:
+				ipi_timer();
+				break;
+			case BFIN_IPI_RESCHEDULE:
+				scheduler_ipi();
+				break;
+			case BFIN_IPI_CALL_FUNC:
+				generic_smp_call_function_interrupt();
+				break;
+			case BFIN_IPI_CPU_STOP:
+				ipi_cpu_stop(cpu);
+				break;
+			default:
+				goto out;
+			}
+			atomic_dec(&bfin_ipi_data->count);
+		} while (msg < BITS_PER_LONG);
+
+	}
+out:
+	return IRQ_HANDLED;
+}
+
+static void bfin_ipi_init(void)
+{
+	unsigned int cpu;
+	struct ipi_data *bfin_ipi_data;
+	for_each_possible_cpu(cpu) {
+		bfin_ipi_data = &per_cpu(bfin_ipi, cpu);
+		atomic_set(&bfin_ipi_data->bits, 0);
+		atomic_set(&bfin_ipi_data->count, 0);
+	}
+}
+
+void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg)
+{
+	unsigned int cpu;
+	struct ipi_data *bfin_ipi_data;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	for_each_cpu(cpu, cpumask) {
+		bfin_ipi_data = &per_cpu(bfin_ipi, cpu);
+		atomic_set_mask((1 << msg), &bfin_ipi_data->bits);
+		atomic_inc(&bfin_ipi_data->count);
+	}
+	local_irq_restore(flags);
+	smp_wmb();
+	for_each_cpu(cpu, cpumask)
+		platform_send_ipi_cpu(cpu, IRQ_SUPPLE_1);
+}
+
+void arch_send_call_function_single_ipi(int cpu)
+{
+	send_ipi(cpumask_of(cpu), BFIN_IPI_CALL_FUNC);
+}
+
+void arch_send_call_function_ipi_mask(const struct cpumask *mask)
+{
+	send_ipi(mask, BFIN_IPI_CALL_FUNC);
+}
+
+void smp_send_reschedule(int cpu)
+{
+	send_ipi(cpumask_of(cpu), BFIN_IPI_RESCHEDULE);
+
+	return;
+}
+
+void smp_send_msg(const struct cpumask *mask, unsigned long type)
+{
+	send_ipi(mask, type);
+}
+
+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))
+		send_ipi(&callmap, BFIN_IPI_CPU_STOP);
+
+	preempt_enable();
+
+	return;
+}
+
+int __cpu_up(unsigned int cpu, struct task_struct *idle)
+{
+	int ret;
+
+	secondary_stack = task_stack_page(idle) + THREAD_SIZE;
+
+	ret = platform_boot_secondary(cpu, idle);
+
+	secondary_stack = NULL;
+
+	return ret;
+}
+
+static void 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 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();
+
+	/* We are done with local CPU inits, unblock the boot CPU. */
+	set_cpu_online(cpu, true);
+	cpu_startup_entry(CPUHP_ONLINE);
+}
+
+void __init smp_prepare_boot_cpu(void)
+{
+}
+
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+	platform_prepare_cpus(max_cpus);
+	bfin_ipi_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 __cpu_disable(void)
+{
+	unsigned int cpu = smp_processor_id();
+
+	if (cpu == 0)
+		return -EPERM;
+
+	set_cpu_online(cpu, false);
+	return 0;
+}
+
+int __cpu_die(unsigned int cpu)
+{
+	return cpu_wait_death(cpu, 5);
+}
+
+void cpu_die(void)
+{
+	(void)cpu_report_death();
+
+	atomic_dec(&init_mm.mm_users);
+	atomic_dec(&init_mm.mm_count);
+
+	local_irq_disable();
+	platform_cpu_die();
+}
+#endif