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authorLuke Browning2008-06-13 14:17:35 +1000
committerJeremy Kerr2008-06-16 14:35:01 +1000
commit2c911a14b74fa9cf815a936f310e4fa85bee77ce (patch)
treea6c5953c1c453cbd9affe378e58629519d9c50d2
parent1f64643aa5f5a17f1723f7ea0f17b7a3a8f632b3 (diff)
powerpc/spufs: synchronize interaction between spu exception handling and time slicing
Time slicing can occur at the same time as spu exception handling resulting in the wakeup of the wrong thread. This change uses the the spu's register_lock to enforce synchronization between bind/unbind and spu exception handling so that they are mutually exclusive. Signed-off-by: Luke Browning <lukebrowning@us.ibm.com> Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
-rw-r--r--arch/powerpc/platforms/cell/spu_base.c42
-rw-r--r--arch/powerpc/platforms/cell/spufs/sched.c14
2 files changed, 37 insertions, 19 deletions
diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c
index 96b5f0f1c11e..78f905bc6a42 100644
--- a/arch/powerpc/platforms/cell/spu_base.c
+++ b/arch/powerpc/platforms/cell/spu_base.c
@@ -219,15 +219,25 @@ static int __spu_trap_data_seg(struct spu *spu, unsigned long ea)
extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap); //XXX
static int __spu_trap_data_map(struct spu *spu, unsigned long ea, u64 dsisr)
{
+ int ret;
+
pr_debug("%s, %lx, %lx\n", __func__, dsisr, ea);
- /* Handle kernel space hash faults immediately.
- User hash faults need to be deferred to process context. */
- if ((dsisr & MFC_DSISR_PTE_NOT_FOUND)
- && REGION_ID(ea) != USER_REGION_ID
- && hash_page(ea, _PAGE_PRESENT, 0x300) == 0) {
- spu_restart_dma(spu);
- return 0;
+ /*
+ * Handle kernel space hash faults immediately. User hash
+ * faults need to be deferred to process context.
+ */
+ if ((dsisr & MFC_DSISR_PTE_NOT_FOUND) &&
+ (REGION_ID(ea) != USER_REGION_ID)) {
+
+ spin_unlock(&spu->register_lock);
+ ret = hash_page(ea, _PAGE_PRESENT, 0x300);
+ spin_lock(&spu->register_lock);
+
+ if (!ret) {
+ spu_restart_dma(spu);
+ return 0;
+ }
}
spu->class_1_dar = ea;
@@ -325,14 +335,12 @@ spu_irq_class_0(int irq, void *data)
spu->class_0_pending |= stat;
spu->class_0_dar = spu_mfc_dar_get(spu);
- spin_unlock(&spu->register_lock);
-
spu->stop_callback(spu, 0);
-
spu->class_0_pending = 0;
spu->class_0_dar = 0;
spu_int_stat_clear(spu, 0, stat);
+ spin_unlock(&spu->register_lock);
return IRQ_HANDLED;
}
@@ -355,13 +363,12 @@ spu_irq_class_1(int irq, void *data)
spu_mfc_dsisr_set(spu, 0ul);
spu_int_stat_clear(spu, 1, stat);
- if (stat & CLASS1_SEGMENT_FAULT_INTR)
- __spu_trap_data_seg(spu, dar);
-
- spin_unlock(&spu->register_lock);
pr_debug("%s: %lx %lx %lx %lx\n", __func__, mask, stat,
dar, dsisr);
+ if (stat & CLASS1_SEGMENT_FAULT_INTR)
+ __spu_trap_data_seg(spu, dar);
+
if (stat & CLASS1_STORAGE_FAULT_INTR)
__spu_trap_data_map(spu, dar, dsisr);
@@ -374,6 +381,8 @@ spu_irq_class_1(int irq, void *data)
spu->class_1_dsisr = 0;
spu->class_1_dar = 0;
+ spin_unlock(&spu->register_lock);
+
return stat ? IRQ_HANDLED : IRQ_NONE;
}
@@ -392,14 +401,12 @@ spu_irq_class_2(int irq, void *data)
mask = spu_int_mask_get(spu, 2);
/* ignore interrupts we're not waiting for */
stat &= mask;
-
/* mailbox interrupts are level triggered. mask them now before
* acknowledging */
if (stat & mailbox_intrs)
spu_int_mask_and(spu, 2, ~(stat & mailbox_intrs));
/* acknowledge all interrupts before the callbacks */
spu_int_stat_clear(spu, 2, stat);
- spin_unlock(&spu->register_lock);
pr_debug("class 2 interrupt %d, %lx, %lx\n", irq, stat, mask);
@@ -419,6 +426,9 @@ spu_irq_class_2(int irq, void *data)
spu->wbox_callback(spu);
spu->stats.class2_intr++;
+
+ spin_unlock(&spu->register_lock);
+
return stat ? IRQ_HANDLED : IRQ_NONE;
}
diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c
index 745dd51ec37f..cd725670b1b5 100644
--- a/arch/powerpc/platforms/cell/spufs/sched.c
+++ b/arch/powerpc/platforms/cell/spufs/sched.c
@@ -230,19 +230,23 @@ static void spu_bind_context(struct spu *spu, struct spu_context *ctx)
ctx->stats.slb_flt_base = spu->stats.slb_flt;
ctx->stats.class2_intr_base = spu->stats.class2_intr;
+ spu_associate_mm(spu, ctx->owner);
+
+ spin_lock_irq(&spu->register_lock);
spu->ctx = ctx;
spu->flags = 0;
ctx->spu = spu;
ctx->ops = &spu_hw_ops;
spu->pid = current->pid;
spu->tgid = current->tgid;
- spu_associate_mm(spu, ctx->owner);
spu->ibox_callback = spufs_ibox_callback;
spu->wbox_callback = spufs_wbox_callback;
spu->stop_callback = spufs_stop_callback;
spu->mfc_callback = spufs_mfc_callback;
- mb();
+ spin_unlock_irq(&spu->register_lock);
+
spu_unmap_mappings(ctx);
+
spu_switch_log_notify(spu, ctx, SWITCH_LOG_START, 0);
spu_restore(&ctx->csa, spu);
spu->timestamp = jiffies;
@@ -423,18 +427,22 @@ static void spu_unbind_context(struct spu *spu, struct spu_context *ctx)
spu_unmap_mappings(ctx);
spu_save(&ctx->csa, spu);
spu_switch_log_notify(spu, ctx, SWITCH_LOG_STOP, 0);
+
+ spin_lock_irq(&spu->register_lock);
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_associate_mm(spu, NULL);
spu->pid = 0;
spu->tgid = 0;
ctx->ops = &spu_backing_ops;
spu->flags = 0;
spu->ctx = NULL;
+ spin_unlock_irq(&spu->register_lock);
+
+ spu_associate_mm(spu, NULL);
ctx->stats.slb_flt +=
(spu->stats.slb_flt - ctx->stats.slb_flt_base);