mirror of https://gitee.com/openkylin/linux.git
368 lines
8.4 KiB
C
368 lines
8.4 KiB
C
/* sched.c - SPU scheduler.
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*
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* Copyright (C) IBM 2005
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* Author: Mark Nutter <mnutter@us.ibm.com>
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*
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* 2006-03-31 NUMA domains added.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#undef DEBUG
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#include <linux/module.h>
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#include <linux/errno.h>
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#include <linux/sched.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/completion.h>
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#include <linux/vmalloc.h>
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#include <linux/smp.h>
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#include <linux/smp_lock.h>
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#include <linux/stddef.h>
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#include <linux/unistd.h>
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#include <linux/numa.h>
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#include <linux/mutex.h>
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#include <linux/notifier.h>
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#include <asm/io.h>
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#include <asm/mmu_context.h>
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#include <asm/spu.h>
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#include <asm/spu_csa.h>
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#include <asm/spu_priv1.h>
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#include "spufs.h"
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#define SPU_MIN_TIMESLICE (100 * HZ / 1000)
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#define SPU_BITMAP_SIZE (((MAX_PRIO+BITS_PER_LONG)/BITS_PER_LONG)+1)
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struct spu_prio_array {
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unsigned long bitmap[SPU_BITMAP_SIZE];
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wait_queue_head_t waitq[MAX_PRIO];
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struct list_head active_list[MAX_NUMNODES];
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struct mutex active_mutex[MAX_NUMNODES];
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};
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static struct spu_prio_array *spu_prio;
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static inline int node_allowed(int node)
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{
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cpumask_t mask;
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if (!nr_cpus_node(node))
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return 0;
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mask = node_to_cpumask(node);
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if (!cpus_intersects(mask, current->cpus_allowed))
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return 0;
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return 1;
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}
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static inline void mm_needs_global_tlbie(struct mm_struct *mm)
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{
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int nr = (NR_CPUS > 1) ? NR_CPUS : NR_CPUS + 1;
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/* Global TLBIE broadcast required with SPEs. */
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__cpus_setall(&mm->cpu_vm_mask, nr);
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}
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static BLOCKING_NOTIFIER_HEAD(spu_switch_notifier);
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static void spu_switch_notify(struct spu *spu, struct spu_context *ctx)
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{
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blocking_notifier_call_chain(&spu_switch_notifier,
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ctx ? ctx->object_id : 0, spu);
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}
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int spu_switch_event_register(struct notifier_block * n)
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{
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return blocking_notifier_chain_register(&spu_switch_notifier, n);
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}
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int spu_switch_event_unregister(struct notifier_block * n)
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{
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return blocking_notifier_chain_unregister(&spu_switch_notifier, n);
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}
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static inline void bind_context(struct spu *spu, struct spu_context *ctx)
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{
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pr_debug("%s: pid=%d SPU=%d NODE=%d\n", __FUNCTION__, current->pid,
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spu->number, spu->node);
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spu->ctx = ctx;
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spu->flags = 0;
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ctx->spu = spu;
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ctx->ops = &spu_hw_ops;
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spu->pid = current->pid;
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spu->prio = current->prio;
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spu->mm = ctx->owner;
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mm_needs_global_tlbie(spu->mm);
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spu->ibox_callback = spufs_ibox_callback;
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spu->wbox_callback = spufs_wbox_callback;
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spu->stop_callback = spufs_stop_callback;
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spu->mfc_callback = spufs_mfc_callback;
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spu->dma_callback = spufs_dma_callback;
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mb();
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spu_unmap_mappings(ctx);
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spu_restore(&ctx->csa, spu);
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spu->timestamp = jiffies;
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spu_cpu_affinity_set(spu, raw_smp_processor_id());
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spu_switch_notify(spu, ctx);
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}
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static inline void unbind_context(struct spu *spu, struct spu_context *ctx)
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{
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pr_debug("%s: unbind pid=%d SPU=%d NODE=%d\n", __FUNCTION__,
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spu->pid, spu->number, spu->node);
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spu_switch_notify(spu, NULL);
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spu_unmap_mappings(ctx);
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spu_save(&ctx->csa, spu);
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spu->timestamp = jiffies;
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ctx->state = SPU_STATE_SAVED;
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spu->ibox_callback = NULL;
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spu->wbox_callback = NULL;
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spu->stop_callback = NULL;
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spu->mfc_callback = NULL;
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spu->dma_callback = NULL;
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spu->mm = NULL;
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spu->pid = 0;
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spu->prio = MAX_PRIO;
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ctx->ops = &spu_backing_ops;
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ctx->spu = NULL;
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spu->flags = 0;
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spu->ctx = NULL;
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}
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static inline void spu_add_wq(wait_queue_head_t * wq, wait_queue_t * wait,
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int prio)
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{
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prepare_to_wait_exclusive(wq, wait, TASK_INTERRUPTIBLE);
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set_bit(prio, spu_prio->bitmap);
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}
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static inline void spu_del_wq(wait_queue_head_t * wq, wait_queue_t * wait,
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int prio)
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{
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u64 flags;
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__set_current_state(TASK_RUNNING);
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spin_lock_irqsave(&wq->lock, flags);
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remove_wait_queue_locked(wq, wait);
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if (list_empty(&wq->task_list))
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clear_bit(prio, spu_prio->bitmap);
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spin_unlock_irqrestore(&wq->lock, flags);
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}
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static void spu_prio_wait(struct spu_context *ctx, u64 flags)
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{
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int prio = current->prio;
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wait_queue_head_t *wq = &spu_prio->waitq[prio];
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DEFINE_WAIT(wait);
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if (ctx->spu)
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return;
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spu_add_wq(wq, &wait, prio);
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if (!signal_pending(current)) {
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up_write(&ctx->state_sema);
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pr_debug("%s: pid=%d prio=%d\n", __FUNCTION__,
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current->pid, current->prio);
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schedule();
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down_write(&ctx->state_sema);
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}
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spu_del_wq(wq, &wait, prio);
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}
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static void spu_prio_wakeup(void)
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{
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int best = sched_find_first_bit(spu_prio->bitmap);
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if (best < MAX_PRIO) {
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wait_queue_head_t *wq = &spu_prio->waitq[best];
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wake_up_interruptible_nr(wq, 1);
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}
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}
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static int get_active_spu(struct spu *spu)
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{
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int node = spu->node;
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struct spu *tmp;
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int rc = 0;
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mutex_lock(&spu_prio->active_mutex[node]);
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list_for_each_entry(tmp, &spu_prio->active_list[node], list) {
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if (tmp == spu) {
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list_del_init(&spu->list);
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rc = 1;
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break;
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}
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}
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mutex_unlock(&spu_prio->active_mutex[node]);
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return rc;
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}
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static void put_active_spu(struct spu *spu)
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{
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int node = spu->node;
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mutex_lock(&spu_prio->active_mutex[node]);
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list_add_tail(&spu->list, &spu_prio->active_list[node]);
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mutex_unlock(&spu_prio->active_mutex[node]);
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}
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static struct spu *spu_get_idle(struct spu_context *ctx, u64 flags)
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{
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struct spu *spu = NULL;
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int node = cpu_to_node(raw_smp_processor_id());
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int n;
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for (n = 0; n < MAX_NUMNODES; n++, node++) {
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node = (node < MAX_NUMNODES) ? node : 0;
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if (!node_allowed(node))
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continue;
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spu = spu_alloc_node(node);
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if (spu)
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break;
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}
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return spu;
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}
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static inline struct spu *spu_get(struct spu_context *ctx, u64 flags)
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{
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/* Future: spu_get_idle() if possible,
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* otherwise try to preempt an active
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* context.
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*/
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return spu_get_idle(ctx, flags);
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}
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/* The three externally callable interfaces
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* for the scheduler begin here.
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*
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* spu_activate - bind a context to SPU, waiting as needed.
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* spu_deactivate - unbind a context from its SPU.
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* spu_yield - yield an SPU if others are waiting.
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*/
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int spu_activate(struct spu_context *ctx, u64 flags)
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{
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struct spu *spu;
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int ret = 0;
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for (;;) {
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if (ctx->spu)
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return 0;
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spu = spu_get(ctx, flags);
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if (spu != NULL) {
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if (ctx->spu != NULL) {
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spu_free(spu);
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spu_prio_wakeup();
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break;
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}
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bind_context(spu, ctx);
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put_active_spu(spu);
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break;
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}
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spu_prio_wait(ctx, flags);
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if (signal_pending(current)) {
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ret = -ERESTARTSYS;
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spu_prio_wakeup();
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break;
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}
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}
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return ret;
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}
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void spu_deactivate(struct spu_context *ctx)
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{
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struct spu *spu;
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int needs_idle;
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spu = ctx->spu;
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if (!spu)
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return;
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needs_idle = get_active_spu(spu);
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unbind_context(spu, ctx);
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if (needs_idle) {
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spu_free(spu);
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spu_prio_wakeup();
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}
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}
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void spu_yield(struct spu_context *ctx)
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{
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struct spu *spu;
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int need_yield = 0;
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if (down_write_trylock(&ctx->state_sema)) {
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if ((spu = ctx->spu) != NULL) {
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int best = sched_find_first_bit(spu_prio->bitmap);
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if (best < MAX_PRIO) {
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pr_debug("%s: yielding SPU %d NODE %d\n",
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__FUNCTION__, spu->number, spu->node);
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spu_deactivate(ctx);
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ctx->state = SPU_STATE_SAVED;
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need_yield = 1;
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} else {
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spu->prio = MAX_PRIO;
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}
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}
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up_write(&ctx->state_sema);
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}
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if (unlikely(need_yield))
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yield();
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}
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int __init spu_sched_init(void)
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{
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int i;
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spu_prio = kzalloc(sizeof(struct spu_prio_array), GFP_KERNEL);
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if (!spu_prio) {
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printk(KERN_WARNING "%s: Unable to allocate priority queue.\n",
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__FUNCTION__);
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return 1;
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}
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for (i = 0; i < MAX_PRIO; i++) {
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init_waitqueue_head(&spu_prio->waitq[i]);
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__clear_bit(i, spu_prio->bitmap);
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}
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__set_bit(MAX_PRIO, spu_prio->bitmap);
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for (i = 0; i < MAX_NUMNODES; i++) {
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mutex_init(&spu_prio->active_mutex[i]);
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INIT_LIST_HEAD(&spu_prio->active_list[i]);
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}
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return 0;
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}
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void __exit spu_sched_exit(void)
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{
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struct spu *spu, *tmp;
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int node;
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for (node = 0; node < MAX_NUMNODES; node++) {
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mutex_lock(&spu_prio->active_mutex[node]);
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list_for_each_entry_safe(spu, tmp, &spu_prio->active_list[node],
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list) {
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list_del_init(&spu->list);
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spu_free(spu);
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}
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mutex_unlock(&spu_prio->active_mutex[node]);
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}
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kfree(spu_prio);
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}
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