From: Arnd Bergmann Date: Tue, 6 Dec 2005 03:52:27 +0000 (-0500) Subject: [PATCH] spufs: fix mailbox polling X-Git-Tag: v2.6.16-rc1~666^2~65 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3a843d7cd30ab6815610d9d6aa66b56df0ee1228;p=linux-2.6 [PATCH] spufs: fix mailbox polling Handling mailbox interrupts was broken in multiple respects, the combination of which was hiding the bugs most of the time. - The ibox interrupt mask was open initially even though there are no waiters on a newly created SPU. - Acknowledging the mailbox interrupt did not work because it is level triggered and the mailbox data is never retrieved from inside the interrupt handler. - The interrupt handler delivered interrupts with a disabled mask if another interrupt is triggered for the same class but a different mask. - The poll function did not enable the interrupt if it had not been enabled, so we might run into the poll timeout if none of the other bugs saved us and no signal was delivered. We probably still have a similar problem with blocking read/write on mailbox files, but that will result in extra wakeup in the worst case, not in incorrect behaviour. Signed-off-by: Arnd Bergmann Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c index 8abd4bd196..f9da79eb3d 100644 --- a/arch/powerpc/platforms/cell/spu_base.c +++ b/arch/powerpc/platforms/cell/spu_base.c @@ -202,12 +202,15 @@ spu_irq_class_0(int irq, void *data, struct pt_regs *regs) int spu_irq_class_0_bottom(struct spu *spu) { - unsigned long stat; + unsigned long stat, mask; spu->class_0_pending = 0; + mask = in_be64(&spu->priv1->int_mask_class0_RW); stat = in_be64(&spu->priv1->int_stat_class0_RW); + stat &= mask; + if (stat & 1) /* invalid MFC DMA */ __spu_trap_invalid_dma(spu); @@ -263,13 +266,15 @@ spu_irq_class_2(int irq, void *data, struct pt_regs *regs) { struct spu *spu; unsigned long stat; + unsigned long mask; spu = data; stat = in_be64(&spu->priv1->int_stat_class2_RW); + mask = in_be64(&spu->priv1->int_mask_class2_RW); - pr_debug("class 2 interrupt %d, %lx, %lx\n", irq, stat, - in_be64(&spu->priv1->int_mask_class2_RW)); + pr_debug("class 2 interrupt %d, %lx, %lx\n", irq, stat, mask); + stat &= mask; if (stat & 1) /* PPC core mailbox */ __spu_trap_mailbox(spu); diff --git a/arch/powerpc/platforms/cell/spufs/backing_ops.c b/arch/powerpc/platforms/cell/spufs/backing_ops.c index 66567c1099..a5c489a53c 100644 --- a/arch/powerpc/platforms/cell/spufs/backing_ops.c +++ b/arch/powerpc/platforms/cell/spufs/backing_ops.c @@ -32,6 +32,7 @@ #include #include #include +#include #include #include @@ -87,6 +88,41 @@ static u32 spu_backing_mbox_stat_read(struct spu_context *ctx) return ctx->csa.prob.mb_stat_R; } +static unsigned int spu_backing_mbox_stat_poll(struct spu_context *ctx, + unsigned int events) +{ + int ret; + u32 stat; + + ret = 0; + spin_lock_irq(&ctx->csa.register_lock); + stat = ctx->csa.prob.mb_stat_R; + + /* if the requested event is there, return the poll + mask, otherwise enable the interrupt to get notified, + but first mark any pending interrupts as done so + we don't get woken up unnecessarily */ + + if (events & (POLLIN | POLLRDNORM)) { + if (stat & 0xff0000) + ret |= POLLIN | POLLRDNORM; + else { + ctx->csa.priv1.int_stat_class0_RW &= ~0x1; + ctx->csa.priv1.int_mask_class2_RW |= 0x1; + } + } + if (events & (POLLOUT | POLLWRNORM)) { + if (stat & 0x00ff00) + ret = POLLOUT | POLLWRNORM; + else { + ctx->csa.priv1.int_stat_class0_RW &= ~0x10; + ctx->csa.priv1.int_mask_class2_RW |= 0x10; + } + } + spin_unlock_irq(&ctx->csa.register_lock); + return ret; +} + static int spu_backing_ibox_read(struct spu_context *ctx, u32 * data) { int ret; @@ -252,6 +288,7 @@ static void spu_backing_runcntl_stop(struct spu_context *ctx) struct spu_context_ops spu_backing_ops = { .mbox_read = spu_backing_mbox_read, .mbox_stat_read = spu_backing_mbox_stat_read, + .mbox_stat_poll = spu_backing_mbox_stat_poll, .ibox_read = spu_backing_ibox_read, .wbox_write = spu_backing_wbox_write, .signal1_read = spu_backing_signal1_read, diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c index af5adc3722..9738de727f 100644 --- a/arch/powerpc/platforms/cell/spufs/file.c +++ b/arch/powerpc/platforms/cell/spufs/file.c @@ -389,20 +389,13 @@ static ssize_t spufs_ibox_read(struct file *file, char __user *buf, static unsigned int spufs_ibox_poll(struct file *file, poll_table *wait) { struct spu_context *ctx = file->private_data; - u32 mbox_stat; unsigned int mask; - spu_acquire(ctx); - - mbox_stat = ctx->ops->mbox_stat_read(ctx); - - spu_release(ctx); - poll_wait(file, &ctx->ibox_wq, wait); - mask = 0; - if (mbox_stat & 0xff0000) - mask |= POLLIN | POLLRDNORM; + spu_acquire(ctx); + mask = ctx->ops->mbox_stat_poll(ctx, POLLIN | POLLRDNORM); + spu_release(ctx); return mask; } @@ -494,18 +487,13 @@ static ssize_t spufs_wbox_write(struct file *file, const char __user *buf, static unsigned int spufs_wbox_poll(struct file *file, poll_table *wait) { struct spu_context *ctx = file->private_data; - u32 mbox_stat; unsigned int mask; - spu_acquire(ctx); - mbox_stat = ctx->ops->mbox_stat_read(ctx); - spu_release(ctx); - poll_wait(file, &ctx->wbox_wq, wait); - mask = 0; - if (mbox_stat & 0x00ff00) - mask = POLLOUT | POLLWRNORM; + spu_acquire(ctx); + mask = ctx->ops->mbox_stat_poll(ctx, POLLOUT | POLLWRNORM); + spu_release(ctx); return mask; } diff --git a/arch/powerpc/platforms/cell/spufs/hw_ops.c b/arch/powerpc/platforms/cell/spufs/hw_ops.c index 68812415ee..9a53e29f9d 100644 --- a/arch/powerpc/platforms/cell/spufs/hw_ops.c +++ b/arch/powerpc/platforms/cell/spufs/hw_ops.c @@ -24,7 +24,7 @@ #include #include #include -#include +#include #include #include #include @@ -58,6 +58,44 @@ static u32 spu_hw_mbox_stat_read(struct spu_context *ctx) return in_be32(&ctx->spu->problem->mb_stat_R); } +static unsigned int spu_hw_mbox_stat_poll(struct spu_context *ctx, + unsigned int events) +{ + struct spu *spu = ctx->spu; + struct spu_priv1 __iomem *priv1 = spu->priv1; + int ret = 0; + u32 stat; + + spin_lock_irq(&spu->register_lock); + stat = in_be32(&spu->problem->mb_stat_R); + + /* if the requested event is there, return the poll + mask, otherwise enable the interrupt to get notified, + but first mark any pending interrupts as done so + we don't get woken up unnecessarily */ + + if (events & (POLLIN | POLLRDNORM)) { + if (stat & 0xff0000) + ret |= POLLIN | POLLRDNORM; + else { + out_be64(&priv1->int_stat_class2_RW, 0x1); + out_be64(&priv1->int_mask_class2_RW, + in_be64(&priv1->int_mask_class2_RW) | 0x1); + } + } + if (events & (POLLOUT | POLLWRNORM)) { + if (stat & 0x00ff00) + ret = POLLOUT | POLLWRNORM; + else { + out_be64(&priv1->int_stat_class2_RW, 0x10); + out_be64(&priv1->int_mask_class2_RW, + in_be64(&priv1->int_mask_class2_RW) | 0x10); + } + } + spin_unlock_irq(&spu->register_lock); + return ret; +} + static int spu_hw_ibox_read(struct spu_context *ctx, u32 * data) { struct spu *spu = ctx->spu; @@ -204,6 +242,7 @@ static void spu_hw_runcntl_stop(struct spu_context *ctx) struct spu_context_ops spu_hw_ops = { .mbox_read = spu_hw_mbox_read, .mbox_stat_read = spu_hw_mbox_stat_read, + .mbox_stat_poll = spu_hw_mbox_stat_poll, .ibox_read = spu_hw_ibox_read, .wbox_write = spu_hw_wbox_write, .signal1_read = spu_hw_signal1_read, diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h index 5bb75f22f7..17cae5e5fd 100644 --- a/arch/powerpc/platforms/cell/spufs/spufs.h +++ b/arch/powerpc/platforms/cell/spufs/spufs.h @@ -66,6 +66,8 @@ struct spu_context { struct spu_context_ops { int (*mbox_read) (struct spu_context * ctx, u32 * data); u32(*mbox_stat_read) (struct spu_context * ctx); + unsigned int (*mbox_stat_poll)(struct spu_context *ctx, + unsigned int events); int (*ibox_read) (struct spu_context * ctx, u32 * data); int (*wbox_write) (struct spu_context * ctx, u32 data); u32(*signal1_read) (struct spu_context * ctx); diff --git a/arch/powerpc/platforms/cell/spufs/switch.c b/arch/powerpc/platforms/cell/spufs/switch.c index 51266257b0..010a9fe55e 100644 --- a/arch/powerpc/platforms/cell/spufs/switch.c +++ b/arch/powerpc/platforms/cell/spufs/switch.c @@ -2155,8 +2155,8 @@ static void init_priv1(struct spu_state *csa) CLASS0_ENABLE_SPU_ERROR_INTR; csa->priv1.int_mask_class1_RW = CLASS1_ENABLE_SEGMENT_FAULT_INTR | CLASS1_ENABLE_STORAGE_FAULT_INTR; - csa->priv1.int_mask_class2_RW = CLASS2_ENABLE_MAILBOX_INTR | - CLASS2_ENABLE_SPU_STOP_INTR | CLASS2_ENABLE_SPU_HALT_INTR; + csa->priv1.int_mask_class2_RW = CLASS2_ENABLE_SPU_STOP_INTR | + CLASS2_ENABLE_SPU_HALT_INTR; } static void init_priv2(struct spu_state *csa)