1 files changed, 348 insertions, 0 deletions

diff --git a/arch/cris/arch-v32/kernel/smp.c b/arch/cris/arch-v32/kernel/smp.c
new file mode 100644
index 000000000000..2c5cae04a95c
--- /dev/null
+++ b/arch/cris/arch-v32/kernel/smp.c
@@ -0,0 +1,348 @@
+#include <asm/delay.h>
+#include <asm/arch/irq.h>
+#include <asm/arch/hwregs/intr_vect.h>
+#include <asm/arch/hwregs/intr_vect_defs.h>
+#include <asm/tlbflush.h>
+#include <asm/mmu_context.h>
+#include <asm/arch/hwregs/mmu_defs_asm.h>
+#include <asm/arch/hwregs/supp_reg.h>
+#include <asm/atomic.h>
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/timex.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/cpumask.h>
+#include <linux/interrupt.h>
+
+#define IPI_SCHEDULE 1
+#define IPI_CALL 2
+#define IPI_FLUSH_TLB 4
+
+#define FLUSH_ALL (void*)0xffffffff
+
+/* Vector of locks used for various atomic operations */
+spinlock_t cris_atomic_locks[] = { [0 ... LOCK_COUNT - 1] = SPIN_LOCK_UNLOCKED};
+
+/* CPU masks */
+cpumask_t cpu_online_map = CPU_MASK_NONE;
+cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
+
+/* Variables used during SMP boot */
+volatile int cpu_now_booting = 0;
+volatile struct thread_info *smp_init_current_idle_thread;
+
+/* Variables used during IPI */
+static DEFINE_SPINLOCK(call_lock);
+static DEFINE_SPINLOCK(tlbstate_lock);
+
+struct call_data_struct {
+        void (*func) (void *info);
+        void *info;
+        int wait;
+};
+
+static struct call_data_struct * call_data;
+
+static struct mm_struct* flush_mm;
+static struct vm_area_struct* flush_vma;
+static unsigned long flush_addr;
+
+extern int setup_irq(int, struct irqaction *);
+
+/* Mode registers */
+static unsigned long irq_regs[NR_CPUS] =
+{
+  regi_irq,
+  regi_irq2
+};
+
+static irqreturn_t crisv32_ipi_interrupt(int irq, void *dev_id, struct pt_regs *regs);
+static int send_ipi(int vector, int wait, cpumask_t cpu_mask);
+static struct irqaction irq_ipi  = { crisv32_ipi_interrupt, SA_INTERRUPT,
+                                     CPU_MASK_NONE, "ipi", NULL, NULL};
+
+extern void cris_mmu_init(void);
+extern void cris_timer_init(void);
+
+/* SMP initialization */
+void __init smp_prepare_cpus(unsigned int max_cpus)
+{
+        int i;
+
+        /* From now on we can expect IPIs so set them up */
+        setup_irq(IPI_INTR_VECT, &irq_ipi);
+
+        /* Mark all possible CPUs as present */
+        for (i = 0; i < max_cpus; i++)
+            cpu_set(i, phys_cpu_present_map);
+}
+
+void __devinit smp_prepare_boot_cpu(void)
+{
+        /* PGD pointer has moved after per_cpu initialization so
+         * update the MMU.
+         */
+        pgd_t **pgd;
+        pgd = (pgd_t**)&per_cpu(current_pgd, smp_processor_id());
+
+        SUPP_BANK_SEL(1);
+        SUPP_REG_WR(RW_MM_TLB_PGD, pgd);
+        SUPP_BANK_SEL(2);
+        SUPP_REG_WR(RW_MM_TLB_PGD, pgd);
+
+        cpu_set(0, cpu_online_map);
+        cpu_set(0, phys_cpu_present_map);
+}
+
+void __init smp_cpus_done(unsigned int max_cpus)
+{
+}
+
+/* Bring one cpu online.*/
+static int __init
+smp_boot_one_cpu(int cpuid)
+{
+        unsigned timeout;
+        struct task_struct *idle;
+
+        idle = fork_idle(cpuid);
+        if (IS_ERR(idle))
+                panic("SMP: fork failed for CPU:%d", cpuid);
+
+        idle->thread_info->cpu = cpuid;
+
+        /* Information to the CPU that is about to boot */
+        smp_init_current_idle_thread = idle->thread_info;
+        cpu_now_booting = cpuid;
+
+        /* Wait for CPU to come online */
+        for (timeout = 0; timeout < 10000; timeout++) {
+                if(cpu_online(cpuid)) {
+                        cpu_now_booting = 0;
+                        smp_init_current_idle_thread = NULL;
+                        return 0; /* CPU online */
+                }
+                udelay(100);
+                barrier();
+        }
+
+        put_task_struct(idle);
+        idle = NULL;
+
+        printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid);
+        return -1;
+}
+
+/* Secondary CPUs starts uing C here. Here we need to setup CPU
+ * specific stuff such as the local timer and the MMU. */
+void __init smp_callin(void)
+{
+        extern void cpu_idle(void);
+
+        int cpu = cpu_now_booting;
+        reg_intr_vect_rw_mask vect_mask = {0};
+
+        /* Initialise the idle task for this CPU */
+        atomic_inc(&init_mm.mm_count);
+        current->active_mm = &init_mm;
+
+        /* Set up MMU */
+        cris_mmu_init();
+        __flush_tlb_all();
+
+        /* Setup local timer. */
+        cris_timer_init();
+
+        /* Enable IRQ and idle */
+        REG_WR(intr_vect, irq_regs[cpu], rw_mask, vect_mask);
+        unmask_irq(IPI_INTR_VECT);
+        unmask_irq(TIMER_INTR_VECT);
+        local_irq_enable();
+
+        cpu_set(cpu, cpu_online_map);
+        cpu_idle();
+}
+
+/* Stop execution on this CPU.*/
+void stop_this_cpu(void* dummy)
+{
+        local_irq_disable();
+        asm volatile("halt");
+}
+
+/* Other calls */
+void smp_send_stop(void)
+{
+        smp_call_function(stop_this_cpu, NULL, 1, 0);
+}
+
+int setup_profiling_timer(unsigned int multiplier)
+{
+        return -EINVAL;
+}
+
+
+/* cache_decay_ticks is used by the scheduler to decide if a process
+ * is "hot" on one CPU. A higher value means a higher penalty to move
+ * a process to another CPU. Our cache is rather small so we report
+ * 1 tick.
+ */
+unsigned long cache_decay_ticks = 1;
+
+int __devinit __cpu_up(unsigned int cpu)
+{
+        smp_boot_one_cpu(cpu);
+        return cpu_online(cpu) ? 0 : -ENOSYS;
+}
+
+void smp_send_reschedule(int cpu)
+{
+        cpumask_t cpu_mask = CPU_MASK_NONE;
+        cpu_set(cpu, cpu_mask);
+        send_ipi(IPI_SCHEDULE, 0, cpu_mask);
+}
+
+/* TLB flushing
+ *
+ * Flush needs to be done on the local CPU and on any other CPU that
+ * may have the same mapping. The mm->cpu_vm_mask is used to keep track
+ * of which CPUs that a specific process has been executed on.
+ */
+void flush_tlb_common(struct mm_struct* mm, struct vm_area_struct* vma, unsigned long addr)
+{
+        unsigned long flags;
+        cpumask_t cpu_mask;
+
+        spin_lock_irqsave(&tlbstate_lock, flags);
+        cpu_mask = (mm == FLUSH_ALL ? CPU_MASK_ALL : mm->cpu_vm_mask);
+        cpu_clear(smp_processor_id(), cpu_mask);
+        flush_mm = mm;
+        flush_vma = vma;
+        flush_addr = addr;
+        send_ipi(IPI_FLUSH_TLB, 1, cpu_mask);
+        spin_unlock_irqrestore(&tlbstate_lock, flags);
+}
+
+void flush_tlb_all(void)
+{
+        __flush_tlb_all();
+        flush_tlb_common(FLUSH_ALL, FLUSH_ALL, 0);
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+        __flush_tlb_mm(mm);
+        flush_tlb_common(mm, FLUSH_ALL, 0);
+        /* No more mappings in other CPUs */
+        cpus_clear(mm->cpu_vm_mask);
+        cpu_set(smp_processor_id(), mm->cpu_vm_mask);
+}
+
+void flush_tlb_page(struct vm_area_struct *vma,
+                           unsigned long addr)
+{
+        __flush_tlb_page(vma, addr);
+        flush_tlb_common(vma->vm_mm, vma, addr);
+}
+
+/* Inter processor interrupts
+ *
+ * The IPIs are used for:
+ *   * Force a schedule on a CPU
+ *   * FLush TLB on other CPUs
+ *   * Call a function on other CPUs
+ */
+
+int send_ipi(int vector, int wait, cpumask_t cpu_mask)
+{
+        int i = 0;
+        reg_intr_vect_rw_ipi ipi = REG_RD(intr_vect, irq_regs[i], rw_ipi);
+        int ret = 0;
+
+        /* Calculate CPUs to send to. */
+        cpus_and(cpu_mask, cpu_mask, cpu_online_map);
+
+        /* Send the IPI. */
+        for_each_cpu_mask(i, cpu_mask)
+        {
+                ipi.vector |= vector;
+                REG_WR(intr_vect, irq_regs[i], rw_ipi, ipi);
+        }
+
+        /* Wait for IPI to finish on other CPUS */
+        if (wait) {
+                for_each_cpu_mask(i, cpu_mask) {
+                        int j;
+                        for (j = 0 ; j < 1000; j++) {
+                                ipi = REG_RD(intr_vect, irq_regs[i], rw_ipi);
+                                if (!ipi.vector)
+                                        break;
+                                udelay(100);
+                        }
+
+                        /* Timeout? */
+                        if (ipi.vector) {
+                                printk("SMP call timeout from %d to %d\n", smp_processor_id(), i);
+                                ret = -ETIMEDOUT;
+                                dump_stack();
+                        }
+                }
+        }
+        return ret;
+}
+
+/*
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.
+ */
+int smp_call_function(void (*func)(void *info), void *info,
+                      int nonatomic, int wait)
+{
+        cpumask_t cpu_mask = CPU_MASK_ALL;
+        struct call_data_struct data;
+        int ret;
+
+        cpu_clear(smp_processor_id(), cpu_mask);
+
+        WARN_ON(irqs_disabled());
+
+        data.func = func;
+        data.info = info;
+        data.wait = wait;
+
+        spin_lock(&call_lock);
+        call_data = &data;
+        ret = send_ipi(IPI_CALL, wait, cpu_mask);
+        spin_unlock(&call_lock);
+
+        return ret;
+}
+
+irqreturn_t crisv32_ipi_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+        void (*func) (void *info) = call_data->func;
+        void *info = call_data->info;
+        reg_intr_vect_rw_ipi ipi;
+
+        ipi = REG_RD(intr_vect, irq_regs[smp_processor_id()], rw_ipi);
+
+        if (ipi.vector & IPI_CALL) {
+                 func(info);
+        }
+        if (ipi.vector & IPI_FLUSH_TLB) {
+                     if (flush_mm == FLUSH_ALL)
+                         __flush_tlb_all();
+                     else if (flush_vma == FLUSH_ALL)
+                        __flush_tlb_mm(flush_mm);
+                     else
+                        __flush_tlb_page(flush_vma, flush_addr);
+        }
+
+        ipi.vector = 0;
+        REG_WR(intr_vect, irq_regs[smp_processor_id()], rw_ipi, ipi);
+
+        return IRQ_HANDLED;
+}
+