[POWERPC] spufs: implement error event delivery to user space
[pandora-kernel.git] / arch / powerpc / platforms / cell / spufs / sched.c
index 963182f..a824b60 100644 (file)
@@ -3,11 +3,7 @@
  * Copyright (C) IBM 2005
  * Author: Mark Nutter <mnutter@us.ibm.com>
  *
- * SPU scheduler, based on Linux thread priority.  For now use
- * a simple "cooperative" yield model with no preemption.  SPU
- * scheduling will eventually be preemptive: When a thread with
- * a higher static priority gets ready to run, then an active SPU
- * context will be preempted and returned to the waitq.
+ * 2006-03-31  NUMA domains added.
  *
  * 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
@@ -26,7 +22,6 @@
 
 #undef DEBUG
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/smp_lock.h>
 #include <linux/stddef.h>
 #include <linux/unistd.h>
+#include <linux/numa.h>
+#include <linux/mutex.h>
 
 #include <asm/io.h>
 #include <asm/mmu_context.h>
 #include <asm/spu.h>
 #include <asm/spu_csa.h>
+#include <asm/spu_priv1.h>
 #include "spufs.h"
 
 #define SPU_MIN_TIMESLICE      (100 * HZ / 1000)
 
 #define SPU_BITMAP_SIZE (((MAX_PRIO+BITS_PER_LONG)/BITS_PER_LONG)+1)
 struct spu_prio_array {
-       atomic_t nr_blocked;
        unsigned long bitmap[SPU_BITMAP_SIZE];
        wait_queue_head_t waitq[MAX_PRIO];
+       struct list_head active_list[MAX_NUMNODES];
+       struct mutex active_mutex[MAX_NUMNODES];
 };
 
-/* spu_runqueue - This is the main runqueue data structure for SPUs. */
-struct spu_runqueue {
-       struct semaphore sem;
-       unsigned long nr_active;
-       unsigned long nr_idle;
-       unsigned long nr_switches;
-       struct list_head active_list;
-       struct list_head idle_list;
-       struct spu_prio_array prio;
-};
-
-static struct spu_runqueue *spu_runqueues = NULL;
-
-static inline struct spu_runqueue *spu_rq(void)
-{
-       /* Future: make this a per-NODE array,
-        * and use cpu_to_node(smp_processor_id())
-        */
-       return spu_runqueues;
-}
-
-static inline struct spu *del_idle(struct spu_runqueue *rq)
-{
-       struct spu *spu;
-
-       BUG_ON(rq->nr_idle <= 0);
-       BUG_ON(list_empty(&rq->idle_list));
-       /* Future: Move SPU out of low-power SRI state. */
-       spu = list_entry(rq->idle_list.next, struct spu, sched_list);
-       list_del_init(&spu->sched_list);
-       rq->nr_idle--;
-       return spu;
-}
-
-static inline void del_active(struct spu_runqueue *rq, struct spu *spu)
-{
-       BUG_ON(rq->nr_active <= 0);
-       BUG_ON(list_empty(&rq->active_list));
-       list_del_init(&spu->sched_list);
-       rq->nr_active--;
-}
-
-static inline void add_idle(struct spu_runqueue *rq, struct spu *spu)
-{
-       /* Future: Put SPU into low-power SRI state. */
-       list_add_tail(&spu->sched_list, &rq->idle_list);
-       rq->nr_idle++;
-}
-
-static inline void add_active(struct spu_runqueue *rq, struct spu *spu)
-{
-       rq->nr_active++;
-       rq->nr_switches++;
-       list_add_tail(&spu->sched_list, &rq->active_list);
-}
-
-static void prio_wakeup(struct spu_runqueue *rq)
-{
-       if (atomic_read(&rq->prio.nr_blocked) && rq->nr_idle) {
-               int best = sched_find_first_bit(rq->prio.bitmap);
-               if (best < MAX_PRIO) {
-                       wait_queue_head_t *wq = &rq->prio.waitq[best];
-                       wake_up_interruptible_nr(wq, 1);
-               }
-       }
-}
+static struct spu_prio_array *spu_prio;
 
-static void prio_wait(struct spu_runqueue *rq, struct spu_context *ctx,
-                     u64 flags)
+static inline int node_allowed(int node)
 {
-       int prio = current->prio;
-       wait_queue_head_t *wq = &rq->prio.waitq[prio];
-       DEFINE_WAIT(wait);
+       cpumask_t mask;
 
-       __set_bit(prio, rq->prio.bitmap);
-       atomic_inc(&rq->prio.nr_blocked);
-       prepare_to_wait_exclusive(wq, &wait, TASK_INTERRUPTIBLE);
-       if (!signal_pending(current)) {
-               up(&rq->sem);
-               up_write(&ctx->state_sema);
-               pr_debug("%s: pid=%d prio=%d\n", __FUNCTION__,
-                        current->pid, current->prio);
-               schedule();
-               down_write(&ctx->state_sema);
-               down(&rq->sem);
-       }
-       finish_wait(wq, &wait);
-       atomic_dec(&rq->prio.nr_blocked);
-       if (!waitqueue_active(wq))
-               __clear_bit(prio, rq->prio.bitmap);
-}
-
-static inline int is_best_prio(struct spu_runqueue *rq)
-{
-       int best_prio;
-
-       best_prio = sched_find_first_bit(rq->prio.bitmap);
-       return (current->prio < best_prio) ? 1 : 0;
+       if (!nr_cpus_node(node))
+               return 0;
+       mask = node_to_cpumask(node);
+       if (!cpus_intersects(mask, current->cpus_allowed))
+               return 0;
+       return 1;
 }
 
 static inline void mm_needs_global_tlbie(struct mm_struct *mm)
 {
+       int nr = (NR_CPUS > 1) ? NR_CPUS : NR_CPUS + 1;
+
        /* Global TLBIE broadcast required with SPEs. */
-#if (NR_CPUS > 1)
-       __cpus_setall(&mm->cpu_vm_mask, NR_CPUS);
-#else
-       __cpus_setall(&mm->cpu_vm_mask, NR_CPUS+1); /* is this ok? */
-#endif
+       __cpus_setall(&mm->cpu_vm_mask, nr);
 }
 
 static inline void bind_context(struct spu *spu, struct spu_context *ctx)
 {
-       pr_debug("%s: pid=%d SPU=%d\n", __FUNCTION__, current->pid,
-                spu->number);
+       pr_debug("%s: pid=%d SPU=%d NODE=%d\n", __FUNCTION__, current->pid,
+                spu->number, spu->node);
        spu->ctx = ctx;
        spu->flags = 0;
-       ctx->flags = 0;
        ctx->spu = spu;
        ctx->ops = &spu_hw_ops;
        spu->pid = current->pid;
@@ -180,16 +90,19 @@ static inline void bind_context(struct spu *spu, struct spu_context *ctx)
        spu->ibox_callback = spufs_ibox_callback;
        spu->wbox_callback = spufs_wbox_callback;
        spu->stop_callback = spufs_stop_callback;
+       spu->mfc_callback = spufs_mfc_callback;
+       spu->dma_callback = spufs_dma_callback;
        mb();
        spu_unmap_mappings(ctx);
        spu_restore(&ctx->csa, spu);
        spu->timestamp = jiffies;
+       spu_cpu_affinity_set(spu, raw_smp_processor_id());
 }
 
 static inline void unbind_context(struct spu *spu, struct spu_context *ctx)
 {
-       pr_debug("%s: unbind pid=%d SPU=%d\n", __FUNCTION__,
-                spu->pid, spu->number);
+       pr_debug("%s: unbind pid=%d SPU=%d NODE=%d\n", __FUNCTION__,
+                spu->pid, spu->number, spu->node);
        spu_unmap_mappings(ctx);
        spu_save(&ctx->csa, spu);
        spu->timestamp = jiffies;
@@ -197,173 +110,159 @@ static inline void unbind_context(struct spu *spu, struct spu_context *ctx)
        spu->ibox_callback = NULL;
        spu->wbox_callback = NULL;
        spu->stop_callback = NULL;
+       spu->mfc_callback = NULL;
+       spu->dma_callback = NULL;
        spu->mm = NULL;
        spu->pid = 0;
        spu->prio = MAX_PRIO;
        ctx->ops = &spu_backing_ops;
        ctx->spu = NULL;
-       ctx->flags = 0;
        spu->flags = 0;
        spu->ctx = NULL;
 }
 
-static void spu_reaper(void *data)
+static inline void spu_add_wq(wait_queue_head_t * wq, wait_queue_t * wait,
+                             int prio)
 {
-       struct spu_context *ctx = data;
-       struct spu *spu;
-
-       down_write(&ctx->state_sema);
-       spu = ctx->spu;
-       if (spu && test_bit(SPU_CONTEXT_PREEMPT, &ctx->flags)) {
-               if (atomic_read(&spu->rq->prio.nr_blocked)) {
-                       pr_debug("%s: spu=%d\n", __func__, spu->number);
-                       ctx->ops->runcntl_stop(ctx);
-                       spu_deactivate(ctx);
-                       wake_up_all(&ctx->stop_wq);
-               } else {
-                       clear_bit(SPU_CONTEXT_PREEMPT, &ctx->flags);
-               }
-       }
-       up_write(&ctx->state_sema);
-       put_spu_context(ctx);
+       prepare_to_wait_exclusive(wq, wait, TASK_INTERRUPTIBLE);
+       set_bit(prio, spu_prio->bitmap);
 }
 
-static void schedule_spu_reaper(struct spu_runqueue *rq, struct spu *spu)
+static inline void spu_del_wq(wait_queue_head_t * wq, wait_queue_t * wait,
+                             int prio)
 {
-       struct spu_context *ctx = get_spu_context(spu->ctx);
-       unsigned long now = jiffies;
-       unsigned long expire = spu->timestamp + SPU_MIN_TIMESLICE;
-
-       set_bit(SPU_CONTEXT_PREEMPT, &ctx->flags);
-       INIT_WORK(&ctx->reap_work, spu_reaper, ctx);
-       if (time_after(now, expire))
-               schedule_work(&ctx->reap_work);
-       else
-               schedule_delayed_work(&ctx->reap_work, expire - now);
-}
+       u64 flags;
 
-static void check_preempt_active(struct spu_runqueue *rq)
-{
-       struct list_head *p;
-       struct spu *worst = NULL;
-
-       list_for_each(p, &rq->active_list) {
-               struct spu *spu = list_entry(p, struct spu, sched_list);
-               struct spu_context *ctx = spu->ctx;
-               if (!test_bit(SPU_CONTEXT_PREEMPT, &ctx->flags)) {
-                       if (!worst || (spu->prio > worst->prio)) {
-                               worst = spu;
-                       }
-               }
-       }
-       if (worst && (current->prio < worst->prio))
-               schedule_spu_reaper(rq, worst);
+       __set_current_state(TASK_RUNNING);
+
+       spin_lock_irqsave(&wq->lock, flags);
+
+       remove_wait_queue_locked(wq, wait);
+       if (list_empty(&wq->task_list))
+               clear_bit(prio, spu_prio->bitmap);
+
+       spin_unlock_irqrestore(&wq->lock, flags);
 }
 
-static struct spu *get_idle_spu(struct spu_context *ctx, u64 flags)
+static void spu_prio_wait(struct spu_context *ctx, u64 flags)
 {
-       struct spu_runqueue *rq;
-       struct spu *spu = NULL;
+       int prio = current->prio;
+       wait_queue_head_t *wq = &spu_prio->waitq[prio];
+       DEFINE_WAIT(wait);
 
-       rq = spu_rq();
-       down(&rq->sem);
-       for (;;) {
-               if (rq->nr_idle > 0) {
-                       if (is_best_prio(rq)) {
-                               /* Fall through. */
-                               spu = del_idle(rq);
-                               break;
-                       } else {
-                               prio_wakeup(rq);
-                               up(&rq->sem);
-                               yield();
-                               if (signal_pending(current)) {
-                                       return NULL;
-                               }
-                               rq = spu_rq();
-                               down(&rq->sem);
-                               continue;
-                       }
-               } else {
-                       check_preempt_active(rq);
-                       prio_wait(rq, ctx, flags);
-                       if (signal_pending(current)) {
-                               prio_wakeup(rq);
-                               spu = NULL;
-                               break;
-                       }
-                       continue;
-               }
+       if (ctx->spu)
+               return;
+
+       spu_add_wq(wq, &wait, prio);
+
+       if (!signal_pending(current)) {
+               up_write(&ctx->state_sema);
+               pr_debug("%s: pid=%d prio=%d\n", __FUNCTION__,
+                        current->pid, current->prio);
+               schedule();
+               down_write(&ctx->state_sema);
        }
-       up(&rq->sem);
-       return spu;
+
+       spu_del_wq(wq, &wait, prio);
 }
 
-static void put_idle_spu(struct spu *spu)
+static void spu_prio_wakeup(void)
 {
-       struct spu_runqueue *rq = spu->rq;
-
-       down(&rq->sem);
-       add_idle(rq, spu);
-       prio_wakeup(rq);
-       up(&rq->sem);
+       int best = sched_find_first_bit(spu_prio->bitmap);
+       if (best < MAX_PRIO) {
+               wait_queue_head_t *wq = &spu_prio->waitq[best];
+               wake_up_interruptible_nr(wq, 1);
+       }
 }
 
 static int get_active_spu(struct spu *spu)
 {
-       struct spu_runqueue *rq = spu->rq;
-       struct list_head *p;
+       int node = spu->node;
        struct spu *tmp;
        int rc = 0;
 
-       down(&rq->sem);
-       list_for_each(p, &rq->active_list) {
-               tmp = list_entry(p, struct spu, sched_list);
+       mutex_lock(&spu_prio->active_mutex[node]);
+       list_for_each_entry(tmp, &spu_prio->active_list[node], list) {
                if (tmp == spu) {
-                       del_active(rq, spu);
+                       list_del_init(&spu->list);
                        rc = 1;
                        break;
                }
        }
-       up(&rq->sem);
+       mutex_unlock(&spu_prio->active_mutex[node]);
        return rc;
 }
 
 static void put_active_spu(struct spu *spu)
 {
-       struct spu_runqueue *rq = spu->rq;
+       int node = spu->node;
 
-       down(&rq->sem);
-       add_active(rq, spu);
-       up(&rq->sem);
+       mutex_lock(&spu_prio->active_mutex[node]);
+       list_add_tail(&spu->list, &spu_prio->active_list[node]);
+       mutex_unlock(&spu_prio->active_mutex[node]);
 }
 
-/* Lock order:
- *     spu_activate() & spu_deactivate() require the
- *     caller to have down_write(&ctx->state_sema).
+static struct spu *spu_get_idle(struct spu_context *ctx, u64 flags)
+{
+       struct spu *spu = NULL;
+       int node = cpu_to_node(raw_smp_processor_id());
+       int n;
+
+       for (n = 0; n < MAX_NUMNODES; n++, node++) {
+               node = (node < MAX_NUMNODES) ? node : 0;
+               if (!node_allowed(node))
+                       continue;
+               spu = spu_alloc_node(node);
+               if (spu)
+                       break;
+       }
+       return spu;
+}
+
+static inline struct spu *spu_get(struct spu_context *ctx, u64 flags)
+{
+       /* Future: spu_get_idle() if possible,
+        * otherwise try to preempt an active
+        * context.
+        */
+       return spu_get_idle(ctx, flags);
+}
+
+/* The three externally callable interfaces
+ * for the scheduler begin here.
  *
- *     The rq->sem is breifly held (inside or outside a
- *     given ctx lock) for list management, but is never
- *     held during save/restore.
+ *     spu_activate    - bind a context to SPU, waiting as needed.
+ *     spu_deactivate  - unbind a context from its SPU.
+ *     spu_yield       - yield an SPU if others are waiting.
  */
 
 int spu_activate(struct spu_context *ctx, u64 flags)
 {
        struct spu *spu;
+       int ret = 0;
 
-       if (ctx->spu)
-               return 0;
-       spu = get_idle_spu(ctx, flags);
-       if (!spu)
-               return (signal_pending(current)) ? -ERESTARTSYS : -EAGAIN;
-       bind_context(spu, ctx);
-       /*
-        * We're likely to wait for interrupts on the same
-        * CPU that we are now on, so send them here.
-        */
-       spu_irq_setaffinity(spu, raw_smp_processor_id());
-       put_active_spu(spu);
-       return 0;
+       for (;;) {
+               if (ctx->spu)
+                       return 0;
+               spu = spu_get(ctx, flags);
+               if (spu != NULL) {
+                       if (ctx->spu != NULL) {
+                               spu_free(spu);
+                               spu_prio_wakeup();
+                               break;
+                       }
+                       bind_context(spu, ctx);
+                       put_active_spu(spu);
+                       break;
+               }
+               spu_prio_wait(ctx, flags);
+               if (signal_pending(current)) {
+                       ret = -ERESTARTSYS;
+                       spu_prio_wakeup();
+                       break;
+               }
+       }
+       return ret;
 }
 
 void spu_deactivate(struct spu_context *ctx)
@@ -376,8 +275,10 @@ void spu_deactivate(struct spu_context *ctx)
                return;
        needs_idle = get_active_spu(spu);
        unbind_context(spu, ctx);
-       if (needs_idle)
-               put_idle_spu(spu);
+       if (needs_idle) {
+               spu_free(spu);
+               spu_prio_wakeup();
+       }
 }
 
 void spu_yield(struct spu_context *ctx)
@@ -385,77 +286,60 @@ void spu_yield(struct spu_context *ctx)
        struct spu *spu;
        int need_yield = 0;
 
-       down_write(&ctx->state_sema);
-       spu = ctx->spu;
-       if (spu && (sched_find_first_bit(spu->rq->prio.bitmap) < MAX_PRIO)) {
-               pr_debug("%s: yielding SPU %d\n", __FUNCTION__, spu->number);
-               spu_deactivate(ctx);
-               ctx->state = SPU_STATE_SAVED;
-               need_yield = 1;
-       } else if (spu) {
-               spu->prio = MAX_PRIO;
+       if (down_write_trylock(&ctx->state_sema)) {
+               if ((spu = ctx->spu) != NULL) {
+                       int best = sched_find_first_bit(spu_prio->bitmap);
+                       if (best < MAX_PRIO) {
+                               pr_debug("%s: yielding SPU %d NODE %d\n",
+                                        __FUNCTION__, spu->number, spu->node);
+                               spu_deactivate(ctx);
+                               ctx->state = SPU_STATE_SAVED;
+                               need_yield = 1;
+                       } else {
+                               spu->prio = MAX_PRIO;
+                       }
+               }
+               up_write(&ctx->state_sema);
        }
-       up_write(&ctx->state_sema);
        if (unlikely(need_yield))
                yield();
 }
 
 int __init spu_sched_init(void)
 {
-       struct spu_runqueue *rq;
-       struct spu *spu;
        int i;
 
-       rq = spu_runqueues = kmalloc(sizeof(struct spu_runqueue), GFP_KERNEL);
-       if (!rq) {
-               printk(KERN_WARNING "%s: Unable to allocate runqueues.\n",
+       spu_prio = kzalloc(sizeof(struct spu_prio_array), GFP_KERNEL);
+       if (!spu_prio) {
+               printk(KERN_WARNING "%s: Unable to allocate priority queue.\n",
                       __FUNCTION__);
                return 1;
        }
-       memset(rq, 0, sizeof(struct spu_runqueue));
-       init_MUTEX(&rq->sem);
-       INIT_LIST_HEAD(&rq->active_list);
-       INIT_LIST_HEAD(&rq->idle_list);
-       rq->nr_active = 0;
-       rq->nr_idle = 0;
-       rq->nr_switches = 0;
-       atomic_set(&rq->prio.nr_blocked, 0);
        for (i = 0; i < MAX_PRIO; i++) {
-               init_waitqueue_head(&rq->prio.waitq[i]);
-               __clear_bit(i, rq->prio.bitmap);
+               init_waitqueue_head(&spu_prio->waitq[i]);
+               __clear_bit(i, spu_prio->bitmap);
        }
-       __set_bit(MAX_PRIO, rq->prio.bitmap);
-       for (;;) {
-               spu = spu_alloc();
-               if (!spu)
-                       break;
-               pr_debug("%s: adding SPU[%d]\n", __FUNCTION__, spu->number);
-               add_idle(rq, spu);
-               spu->rq = rq;
-               spu->timestamp = jiffies;
-       }
-       if (!rq->nr_idle) {
-               printk(KERN_WARNING "%s: No available SPUs.\n", __FUNCTION__);
-               kfree(rq);
-               return 1;
+       __set_bit(MAX_PRIO, spu_prio->bitmap);
+       for (i = 0; i < MAX_NUMNODES; i++) {
+               mutex_init(&spu_prio->active_mutex[i]);
+               INIT_LIST_HEAD(&spu_prio->active_list[i]);
        }
        return 0;
 }
 
 void __exit spu_sched_exit(void)
 {
-       struct spu_runqueue *rq = spu_rq();
-       struct spu *spu;
-
-       if (!rq) {
-               printk(KERN_WARNING "%s: no runqueues!\n", __FUNCTION__);
-               return;
-       }
-       while (rq->nr_idle > 0) {
-               spu = del_idle(rq);
-               if (!spu)
-                       break;
-               spu_free(spu);
+       struct spu *spu, *tmp;
+       int node;
+
+       for (node = 0; node < MAX_NUMNODES; node++) {
+               mutex_lock(&spu_prio->active_mutex[node]);
+               list_for_each_entry_safe(spu, tmp, &spu_prio->active_list[node],
+                                        list) {
+                       list_del_init(&spu->list);
+                       spu_free(spu);
+               }
+               mutex_unlock(&spu_prio->active_mutex[node]);
        }
-       kfree(rq);
+       kfree(spu_prio);
 }