kernel-fxtec-pro1x/arch/powerpc/platforms/cell/spufs/sched.c
Arnd Bergmann 8676727779 [POWERPC] spufs: add infrastructure for finding elf objects
This adds an 'object-id' file that the spe library can
use to store a pointer to its ELF object. This was
originally meant for use by oprofile, but is now
also used by the GNU debugger, if available.

In order for oprofile to find the location in an spu-elf
binary where an event counter triggered, we need a way
to identify the binary in the first place.

Unfortunately, that binary itself can be embedded in a
powerpc ELF binary. Since we can assume it is mapped into
the effective address space of the running process,
have that one write the pointer value into a new spufs
file.

When a context switch occurs, pass the user value to
the profiler so that can look at the mapped file (with
some care).

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-05 09:21:02 +10:00

367 lines
8.4 KiB
C

/* sched.c - SPU scheduler.
*
* Copyright (C) IBM 2005
* Author: Mark Nutter <mnutter@us.ibm.com>
*
* 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
* the Free Software Foundation; either version 2, 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, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#undef DEBUG
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/completion.h>
#include <linux/vmalloc.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/numa.h>
#include <linux/mutex.h>
#include <linux/notifier.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 {
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];
};
static struct spu_prio_array *spu_prio;
static inline int node_allowed(int node)
{
cpumask_t mask;
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. */
__cpus_setall(&mm->cpu_vm_mask, nr);
}
static BLOCKING_NOTIFIER_HEAD(spu_switch_notifier);
static void spu_switch_notify(struct spu *spu, struct spu_context *ctx)
{
blocking_notifier_call_chain(&spu_switch_notifier,
ctx ? ctx->object_id : 0, spu);
}
int spu_switch_event_register(struct notifier_block * n)
{
return blocking_notifier_chain_register(&spu_switch_notifier, n);
}
int spu_switch_event_unregister(struct notifier_block * n)
{
return blocking_notifier_chain_unregister(&spu_switch_notifier, n);
}
static inline void bind_context(struct spu *spu, struct spu_context *ctx)
{
pr_debug("%s: pid=%d SPU=%d NODE=%d\n", __FUNCTION__, current->pid,
spu->number, spu->node);
spu->ctx = ctx;
spu->flags = 0;
ctx->spu = spu;
ctx->ops = &spu_hw_ops;
spu->pid = current->pid;
spu->prio = current->prio;
spu->mm = ctx->owner;
mm_needs_global_tlbie(spu->mm);
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());
spu_switch_notify(spu, ctx);
}
static inline void unbind_context(struct spu *spu, struct spu_context *ctx)
{
pr_debug("%s: unbind pid=%d SPU=%d NODE=%d\n", __FUNCTION__,
spu->pid, spu->number, spu->node);
spu_switch_notify(spu, NULL);
spu_unmap_mappings(ctx);
spu_save(&ctx->csa, spu);
spu->timestamp = jiffies;
ctx->state = SPU_STATE_SAVED;
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;
spu->flags = 0;
spu->ctx = NULL;
}
static inline void spu_add_wq(wait_queue_head_t * wq, wait_queue_t * wait,
int prio)
{
prepare_to_wait_exclusive(wq, wait, TASK_INTERRUPTIBLE);
set_bit(prio, spu_prio->bitmap);
}
static inline void spu_del_wq(wait_queue_head_t * wq, wait_queue_t * wait,
int prio)
{
u64 flags;
__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 void spu_prio_wait(struct spu_context *ctx, u64 flags)
{
int prio = current->prio;
wait_queue_head_t *wq = &spu_prio->waitq[prio];
DEFINE_WAIT(wait);
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);
}
spu_del_wq(wq, &wait, prio);
}
static void spu_prio_wakeup(void)
{
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)
{
int node = spu->node;
struct spu *tmp;
int rc = 0;
mutex_lock(&spu_prio->active_mutex[node]);
list_for_each_entry(tmp, &spu_prio->active_list[node], list) {
if (tmp == spu) {
list_del_init(&spu->list);
rc = 1;
break;
}
}
mutex_unlock(&spu_prio->active_mutex[node]);
return rc;
}
static void put_active_spu(struct spu *spu)
{
int node = spu->node;
mutex_lock(&spu_prio->active_mutex[node]);
list_add_tail(&spu->list, &spu_prio->active_list[node]);
mutex_unlock(&spu_prio->active_mutex[node]);
}
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.
*
* 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;
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)
{
struct spu *spu;
int needs_idle;
spu = ctx->spu;
if (!spu)
return;
needs_idle = get_active_spu(spu);
unbind_context(spu, ctx);
if (needs_idle) {
spu_free(spu);
spu_prio_wakeup();
}
}
void spu_yield(struct spu_context *ctx)
{
struct spu *spu;
int need_yield = 0;
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);
}
if (unlikely(need_yield))
yield();
}
int __init spu_sched_init(void)
{
int i;
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;
}
for (i = 0; i < MAX_PRIO; i++) {
init_waitqueue_head(&spu_prio->waitq[i]);
__clear_bit(i, spu_prio->bitmap);
}
__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 *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(spu_prio);
}