Blackfin arch: SMP supporting patchset: Blackfin header files and machine common code

Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like

In this patch, we provide SMP extend to Blackfin header files
and machine common code

Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

1 files changed, 476 insertions, 0 deletions

diff --git a/arch/blackfin/mach-common/smp.c b/arch/blackfin/mach-common/smp.c
new file mode 100644
index 000000000000..7aeecedd3147
--- /dev/null
+++ b/arch/blackfin/mach-common/smp.c
@@ -0,0 +1,476 @@
+/*
+ * File:         arch/blackfin/kernel/smp.c
+ * Author:       Philippe Gerum <rpm@xenomai.org>
+ * IPI management based on arch/arm/kernel/smp.c.
+ *
+ *               Copyright 2007 Analog Devices Inc.
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.  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, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#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/profile.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/cpu.h>
+#include <linux/smp.h>
+#include <linux/seq_file.h>
+#include <linux/irq.h>
+#include <asm/atomic.h>
+#include <asm/cacheflush.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 <linux/err.h>
+
+struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
+
+void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
+	*init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
+	*init_saved_dcplb_fault_addr_coreb;
+
+cpumask_t cpu_possible_map;
+EXPORT_SYMBOL(cpu_possible_map);
+
+cpumask_t cpu_online_map;
+EXPORT_SYMBOL(cpu_online_map);
+
+#define BFIN_IPI_RESCHEDULE   0
+#define BFIN_IPI_CALL_FUNC    1
+#define BFIN_IPI_CPU_STOP     2
+
+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 pending;
+	cpumask_t waitmask;
+};
+
+static struct blackfin_flush_data smp_flush_data;
+
+static DEFINE_SPINLOCK(stop_lock);
+
+struct ipi_message {
+	struct list_head list;
+	unsigned long type;
+	struct smp_call_struct call_struct;
+};
+
+struct ipi_message_queue {
+	struct list_head head;
+	spinlock_t lock;
+	unsigned long count;
+};
+
+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);
+
+	cpu_clear(cpu, cpu_online_map);
+
+	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));
+
+	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;
+	cpu_clear(cpu, msg->call_struct.pending);
+	func(info);
+	if (wait)
+		cpu_clear(cpu, msg->call_struct.waitmask);
+	else
+		kfree(msg);
+}
+
+static irqreturn_t ipi_handler(int irq, void *dev_instance)
+{
+	struct ipi_message *msg, *mg;
+	struct ipi_message_queue *msg_queue;
+	unsigned int cpu = smp_processor_id();
+
+	platform_clear_ipi(cpu);
+
+	msg_queue = &__get_cpu_var(ipi_msg_queue);
+	msg_queue->count++;
+
+	spin_lock(&msg_queue->lock);
+	list_for_each_entry_safe(msg, mg, &msg_queue->head, list) {
+		list_del(&msg->list);
+		switch (msg->type) {
+		case BFIN_IPI_RESCHEDULE:
+			/* That's the easiest one; leave it to
+			 * return_from_int. */
+			kfree(msg);
+			break;
+		case BFIN_IPI_CALL_FUNC:
+			ipi_call_function(cpu, msg);
+			break;
+		case BFIN_IPI_CPU_STOP:
+			ipi_cpu_stop(cpu);
+			kfree(msg);
+			break;
+		default:
+			printk(KERN_CRIT "CPU%u: Unknown IPI message \
+			0x%lx\n", cpu, msg->type);
+			kfree(msg);
+			break;
+		}
+	}
+	spin_unlock(&msg_queue->lock);
+	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);
+		INIT_LIST_HEAD(&msg_queue->head);
+		spin_lock_init(&msg_queue->lock);
+		msg_queue->count = 0;
+	}
+}
+
+int smp_call_function(void (*func)(void *info), void *info, int wait)
+{
+	unsigned int cpu;
+	cpumask_t callmap;
+	unsigned long flags;
+	struct ipi_message_queue *msg_queue;
+	struct ipi_message *msg;
+
+	callmap = cpu_online_map;
+	cpu_clear(smp_processor_id(), callmap);
+	if (cpus_empty(callmap))
+		return 0;
+
+	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+	INIT_LIST_HEAD(&msg->list);
+	msg->call_struct.func = func;
+	msg->call_struct.info = info;
+	msg->call_struct.wait = wait;
+	msg->call_struct.pending = callmap;
+	msg->call_struct.waitmask = callmap;
+	msg->type = BFIN_IPI_CALL_FUNC;
+
+	for_each_cpu_mask(cpu, callmap) {
+		msg_queue = &per_cpu(ipi_msg_queue, cpu);
+		spin_lock_irqsave(&msg_queue->lock, flags);
+		list_add(&msg->list, &msg_queue->head);
+		spin_unlock_irqrestore(&msg_queue->lock, flags);
+		platform_send_ipi_cpu(cpu);
+	}
+	if (wait) {
+		while (!cpus_empty(msg->call_struct.waitmask))
+			blackfin_dcache_invalidate_range(
+				(unsigned long)(&msg->call_struct.waitmask),
+				(unsigned long)(&msg->call_struct.waitmask));
+		kfree(msg);
+	}
+	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;
+	unsigned long flags;
+	struct ipi_message_queue *msg_queue;
+	struct ipi_message *msg;
+
+	if (cpu_is_offline(cpu))
+		return 0;
+	cpus_clear(callmap);
+	cpu_set(cpu, callmap);
+
+	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+	INIT_LIST_HEAD(&msg->list);
+	msg->call_struct.func = func;
+	msg->call_struct.info = info;
+	msg->call_struct.wait = wait;
+	msg->call_struct.pending = callmap;
+	msg->call_struct.waitmask = callmap;
+	msg->type = BFIN_IPI_CALL_FUNC;
+
+	msg_queue = &per_cpu(ipi_msg_queue, cpu);
+	spin_lock_irqsave(&msg_queue->lock, flags);
+	list_add(&msg->list, &msg_queue->head);
+	spin_unlock_irqrestore(&msg_queue->lock, flags);
+	platform_send_ipi_cpu(cpu);
+
+	if (wait) {
+		while (!cpus_empty(msg->call_struct.waitmask))
+			blackfin_dcache_invalidate_range(
+				(unsigned long)(&msg->call_struct.waitmask),
+				(unsigned long)(&msg->call_struct.waitmask));
+		kfree(msg);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(smp_call_function_single);
+
+void smp_send_reschedule(int cpu)
+{
+	unsigned long flags;
+	struct ipi_message_queue *msg_queue;
+	struct ipi_message *msg;
+
+	if (cpu_is_offline(cpu))
+		return;
+
+	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+	memset(msg, 0, sizeof(msg));
+	INIT_LIST_HEAD(&msg->list);
+	msg->type = BFIN_IPI_RESCHEDULE;
+
+	msg_queue = &per_cpu(ipi_msg_queue, cpu);
+	spin_lock_irqsave(&msg_queue->lock, flags);
+	list_add(&msg->list, &msg_queue->head);
+	spin_unlock_irqrestore(&msg_queue->lock, flags);
+	platform_send_ipi_cpu(cpu);
+
+	return;
+}
+
+void smp_send_stop(void)
+{
+	unsigned int cpu;
+	cpumask_t callmap;
+	unsigned long flags;
+	struct ipi_message_queue *msg_queue;
+	struct ipi_message *msg;
+
+	callmap = cpu_online_map;
+	cpu_clear(smp_processor_id(), callmap);
+	if (cpus_empty(callmap))
+		return;
+
+	msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
+	memset(msg, 0, sizeof(msg));
+	INIT_LIST_HEAD(&msg->list);
+	msg->type = BFIN_IPI_CPU_STOP;
+
+	for_each_cpu_mask(cpu, callmap) {
+		msg_queue = &per_cpu(ipi_msg_queue, cpu);
+		spin_lock_irqsave(&msg_queue->lock, flags);
+		list_add(&msg->list, &msg_queue->head);
+		spin_unlock_irqrestore(&msg_queue->lock, flags);
+		platform_send_ipi_cpu(cpu);
+	}
+	return;
+}
+
+int __cpuinit __cpu_up(unsigned int cpu)
+{
+	struct task_struct *idle;
+	int ret;
+
+	idle = fork_idle(cpu);
+	if (IS_ERR(idle)) {
+		printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
+		return PTR_ERR(idle);
+	}
+
+	secondary_stack = task_stack_page(idle) + THREAD_SIZE;
+	smp_wmb();
+
+	ret = platform_boot_secondary(cpu, idle);
+
+	if (ret) {
+		cpu_clear(cpu, cpu_present_map);
+		printk(KERN_CRIT "CPU%u: processor failed to boot (%d)\n", cpu, ret);
+		free_task(idle);
+	} else
+		cpu_set(cpu, cpu_online_map);
+
+	secondary_stack = NULL;
+
+	return ret;
+}
+
+static void __cpuinit setup_secondary(unsigned int cpu)
+{
+#ifndef CONFIG_TICK_SOURCE_SYSTMR0
+	struct irq_desc *timer_desc;
+#endif
+	unsigned long ilat;
+
+	bfin_write_IMASK(0);
+	CSYNC();
+	ilat = bfin_read_ILAT();
+	CSYNC();
+	bfin_write_ILAT(ilat);
+	CSYNC();
+
+	/* Reserve the PDA space for the secondary CPU. */
+	reserve_pda();
+
+	/* Enable interrupt levels IVG7-15. IARs have been already
+	 * programmed by the boot CPU.  */
+	irq_flags |= IMASK_IVG15 |
+	    IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
+	    IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
+
+#ifdef CONFIG_TICK_SOURCE_SYSTMR0
+	/* Power down the core timer, just to play safe. */
+	bfin_write_TCNTL(0);
+
+	/* system timer0 has been setup by CoreA. */
+#else
+	timer_desc = irq_desc + IRQ_CORETMR;
+	setup_core_timer();
+	timer_desc->chip->enable(IRQ_CORETMR);
+#endif
+}
+
+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 = 0x%x) at %pF\n",
+			(int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
+		printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
+		printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
+#endif
+		printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
+			init_retx_coreb);
+	}
+
+	/*
+	 * 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();
+
+	bfin_setup_caches(cpu);
+
+	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;
+	BUG_ON(current->mm);	/* Can't be, but better be safe than sorry. */
+
+	preempt_disable();
+
+	setup_secondary(cpu);
+
+	local_irq_enable();
+
+	platform_secondary_init(cpu);
+
+	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(&ipi_handler);
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+	unsigned long bogosum = 0;
+	unsigned int cpu;
+
+	for_each_online_cpu(cpu)
+		bogosum += per_cpu(cpu_data, cpu).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;
+
+	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");
+}
+EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
+
+#ifdef __ARCH_SYNC_CORE_DCACHE
+unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
+
+void resync_core_dcache(void)
+{
+	unsigned int cpu = get_cpu();
+	blackfin_invalidate_entire_dcache();
+	++per_cpu(cpu_data, cpu).dcache_invld_count;
+	put_cpu();
+}
+EXPORT_SYMBOL(resync_core_dcache);
+#endif