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