From: Jeremy Kerr Date: Thu, 20 Dec 2007 07:39:59 +0000 (+0900) Subject: [POWERPC] spufs: rework class 0 and 1 interrupt handling X-Git-Tag: v3.12-rc1~24022^2~215 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d6ad39bc53521275d14fde86bfb94d9b2ddb7a08;p=kernel%2Fkernel-generic.git [POWERPC] spufs: rework class 0 and 1 interrupt handling Based on original patches from Arnd Bergmann ; and Luke Browning Currently, spu contexts need to be loaded to the SPU in order to take class 0 and class 1 exceptions. This change makes the actual interrupt-handlers much simpler (ie, set the exception information in the context save area), and defers the handling code to the spufs_handle_class[01] functions, called from spufs_run_spu. This should improve the concurrency of the spu scheduling leading to greater SPU utilization when SPUs are overcommited. Signed-off-by: Jeremy Kerr Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/platforms/cell/spu_base.c b/arch/powerpc/platforms/cell/spu_base.c index a560277..fb266ae 100644 --- a/arch/powerpc/platforms/cell/spu_base.c +++ b/arch/powerpc/platforms/cell/spu_base.c @@ -132,27 +132,6 @@ int spu_64k_pages_available(void) } EXPORT_SYMBOL_GPL(spu_64k_pages_available); -static int __spu_trap_invalid_dma(struct spu *spu) -{ - pr_debug("%s\n", __FUNCTION__); - spu->dma_callback(spu, SPE_EVENT_INVALID_DMA); - return 0; -} - -static int __spu_trap_dma_align(struct spu *spu) -{ - pr_debug("%s\n", __FUNCTION__); - spu->dma_callback(spu, SPE_EVENT_DMA_ALIGNMENT); - return 0; -} - -static int __spu_trap_error(struct spu *spu) -{ - pr_debug("%s\n", __FUNCTION__); - spu->dma_callback(spu, SPE_EVENT_SPE_ERROR); - return 0; -} - static void spu_restart_dma(struct spu *spu) { struct spu_priv2 __iomem *priv2 = spu->priv2; @@ -252,10 +231,12 @@ static int __spu_trap_data_map(struct spu *spu, unsigned long ea, u64 dsisr) return 1; } + spu->class_0_pending = 0; spu->dar = ea; spu->dsisr = dsisr; - mb(); + spu->stop_callback(spu); + return 0; } @@ -335,12 +316,13 @@ spu_irq_class_0(int irq, void *data) spu = data; + spin_lock(&spu->register_lock); mask = spu_int_mask_get(spu, 0); - stat = spu_int_stat_get(spu, 0); - stat &= mask; + stat = spu_int_stat_get(spu, 0) & mask; - spin_lock(&spu->register_lock); spu->class_0_pending |= stat; + spu->dsisr = spu_mfc_dsisr_get(spu); + spu->dar = spu_mfc_dar_get(spu); spin_unlock(&spu->register_lock); spu->stop_callback(spu); @@ -350,31 +332,6 @@ spu_irq_class_0(int irq, void *data) return IRQ_HANDLED; } -int -spu_irq_class_0_bottom(struct spu *spu) -{ - unsigned long flags; - unsigned long stat; - - spin_lock_irqsave(&spu->register_lock, flags); - stat = spu->class_0_pending; - spu->class_0_pending = 0; - - if (stat & CLASS0_DMA_ALIGNMENT_INTR) - __spu_trap_dma_align(spu); - - if (stat & CLASS0_INVALID_DMA_COMMAND_INTR) - __spu_trap_invalid_dma(spu); - - if (stat & CLASS0_SPU_ERROR_INTR) - __spu_trap_error(spu); - - spin_unlock_irqrestore(&spu->register_lock, flags); - - return (stat & CLASS0_INTR_MASK) ? -EIO : 0; -} -EXPORT_SYMBOL_GPL(spu_irq_class_0_bottom); - static irqreturn_t spu_irq_class_1(int irq, void *data) { diff --git a/arch/powerpc/platforms/cell/spufs/fault.c b/arch/powerpc/platforms/cell/spufs/fault.c index 0635f29..720e111 100644 --- a/arch/powerpc/platforms/cell/spufs/fault.c +++ b/arch/powerpc/platforms/cell/spufs/fault.c @@ -28,46 +28,69 @@ #include "spufs.h" -static void spufs_handle_dma_error(struct spu_context *ctx, +/** + * Handle an SPE event, depending on context SPU_CREATE_EVENTS_ENABLED flag. + * + * If the context was created with events, we just set the return event. + * Otherwise, send an appropriate signal to the process. + */ +static void spufs_handle_event(struct spu_context *ctx, unsigned long ea, int type) { + siginfo_t info; + if (ctx->flags & SPU_CREATE_EVENTS_ENABLED) { ctx->event_return |= type; wake_up_all(&ctx->stop_wq); - } else { - siginfo_t info; - memset(&info, 0, sizeof(info)); - - switch (type) { - case SPE_EVENT_INVALID_DMA: - info.si_signo = SIGBUS; - info.si_code = BUS_OBJERR; - break; - case SPE_EVENT_SPE_DATA_STORAGE: - info.si_signo = SIGBUS; - info.si_addr = (void __user *)ea; - info.si_code = BUS_ADRERR; - break; - case SPE_EVENT_DMA_ALIGNMENT: - info.si_signo = SIGBUS; - /* DAR isn't set for an alignment fault :( */ - info.si_code = BUS_ADRALN; - break; - case SPE_EVENT_SPE_ERROR: - info.si_signo = SIGILL; - info.si_addr = (void __user *)(unsigned long) - ctx->ops->npc_read(ctx) - 4; - info.si_code = ILL_ILLOPC; - break; - } - if (info.si_signo) - force_sig_info(info.si_signo, &info, current); + return; } + + memset(&info, 0, sizeof(info)); + + switch (type) { + case SPE_EVENT_INVALID_DMA: + info.si_signo = SIGBUS; + info.si_code = BUS_OBJERR; + break; + case SPE_EVENT_SPE_DATA_STORAGE: + info.si_signo = SIGBUS; + info.si_addr = (void __user *)ea; + info.si_code = BUS_ADRERR; + break; + case SPE_EVENT_DMA_ALIGNMENT: + info.si_signo = SIGBUS; + /* DAR isn't set for an alignment fault :( */ + info.si_code = BUS_ADRALN; + break; + case SPE_EVENT_SPE_ERROR: + info.si_signo = SIGILL; + info.si_addr = (void __user *)(unsigned long) + ctx->ops->npc_read(ctx) - 4; + info.si_code = ILL_ILLOPC; + break; + } + + if (info.si_signo) + force_sig_info(info.si_signo, &info, current); } -void spufs_dma_callback(struct spu *spu, int type) +int spufs_handle_class0(struct spu_context *ctx) { - spufs_handle_dma_error(spu->ctx, spu->dar, type); + unsigned long stat = ctx->csa.class_0_pending & CLASS0_INTR_MASK; + + if (likely(!stat)) + return 0; + + if (stat & CLASS0_DMA_ALIGNMENT_INTR) + spufs_handle_event(ctx, ctx->csa.dar, SPE_EVENT_DMA_ALIGNMENT); + + if (stat & CLASS0_INVALID_DMA_COMMAND_INTR) + spufs_handle_event(ctx, ctx->csa.dar, SPE_EVENT_INVALID_DMA); + + if (stat & CLASS0_SPU_ERROR_INTR) + spufs_handle_event(ctx, ctx->csa.dar, SPE_EVENT_SPE_ERROR); + + return -EIO; } /* @@ -95,16 +118,8 @@ int spufs_handle_class1(struct spu_context *ctx) * in time, we can still expect to get the same fault * the immediately after the context restore. */ - if (ctx->state == SPU_STATE_RUNNABLE) { - ea = ctx->spu->dar; - dsisr = ctx->spu->dsisr; - ctx->spu->dar= ctx->spu->dsisr = 0; - } else { - ea = ctx->csa.priv1.mfc_dar_RW; - dsisr = ctx->csa.priv1.mfc_dsisr_RW; - ctx->csa.priv1.mfc_dar_RW = 0; - ctx->csa.priv1.mfc_dsisr_RW = 0; - } + ea = ctx->csa.dar; + dsisr = ctx->csa.dsisr; if (!(dsisr & (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED))) return 0; @@ -132,6 +147,14 @@ int spufs_handle_class1(struct spu_context *ctx) ret = spu_handle_mm_fault(current->mm, ea, dsisr, &flt); spu_acquire(ctx); + + /* + * Clear dsisr under ctxt lock after handling the fault, so that + * time slicing will not preempt the context while the page fault + * handler is running. Context switch code removes mappings. + */ + ctx->csa.dar = ctx->csa.dsisr = 0; + /* * If we handled the fault successfully and are in runnable * state, restart the DMA. @@ -152,7 +175,7 @@ int spufs_handle_class1(struct spu_context *ctx) if (ctx->spu) ctx->ops->restart_dma(ctx); } else - spufs_handle_dma_error(ctx, ea, SPE_EVENT_SPE_DATA_STORAGE); + spufs_handle_event(ctx, ea, SPE_EVENT_SPE_DATA_STORAGE); spuctx_switch_state(ctx, SPU_UTIL_SYSTEM); return ret; diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c index b3cc1dd..3b3de6c 100644 --- a/arch/powerpc/platforms/cell/spufs/run.c +++ b/arch/powerpc/platforms/cell/spufs/run.c @@ -15,7 +15,30 @@ void spufs_stop_callback(struct spu *spu) { struct spu_context *ctx = spu->ctx; - wake_up_all(&ctx->stop_wq); + /* + * It should be impossible to preempt a context while an exception + * is being processed, since the context switch code is specially + * coded to deal with interrupts ... But, just in case, sanity check + * the context pointer. It is OK to return doing nothing since + * the exception will be regenerated when the context is resumed. + */ + if (ctx) { + /* Copy exception arguments into module specific structure */ + ctx->csa.class_0_pending = spu->class_0_pending; + ctx->csa.dsisr = spu->dsisr; + ctx->csa.dar = spu->dar; + + /* ensure that the exception status has hit memory before a + * thread waiting on the context's stop queue is woken */ + smp_wmb(); + + wake_up_all(&ctx->stop_wq); + } + + /* Clear callback arguments from spu structure */ + spu->class_0_pending = 0; + spu->dsisr = 0; + spu->dar = 0; } static inline int spu_stopped(struct spu_context *ctx, u32 *stat) @@ -29,9 +52,9 @@ static inline int spu_stopped(struct spu_context *ctx, u32 *stat) if (ctx->state != SPU_STATE_RUNNABLE || test_bit(SPU_SCHED_NOTIFY_ACTIVE, &ctx->sched_flags)) return 1; - pte_fault = spu->dsisr & + pte_fault = ctx->csa.dsisr & (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED); - return (!(*stat & SPU_STATUS_RUNNING) || pte_fault || spu->class_0_pending) ? + return (!(*stat & SPU_STATUS_RUNNING) || pte_fault || ctx->csa.class_0_pending) ? 1 : 0; } @@ -287,18 +310,6 @@ static int spu_process_callback(struct spu_context *ctx) return ret; } -static inline int spu_process_events(struct spu_context *ctx) -{ - struct spu *spu = ctx->spu; - int ret = 0; - - if (spu->class_0_pending) - ret = spu_irq_class_0_bottom(spu); - if (!ret && signal_pending(current)) - ret = -ERESTARTSYS; - return ret; -} - long spufs_run_spu(struct spu_context *ctx, u32 *npc, u32 *event) { int ret; @@ -364,13 +375,20 @@ long spufs_run_spu(struct spu_context *ctx, u32 *npc, u32 *event) if (ret) break; + ret = spufs_handle_class0(ctx); + if (ret) + break; + if (unlikely(ctx->state != SPU_STATE_RUNNABLE)) { ret = spu_reacquire_runnable(ctx, npc, &status); if (ret) goto out2; continue; } - ret = spu_process_events(ctx); + + if (signal_pending(current)) + ret = -ERESTARTSYS; + } while (!ret && !(status & (SPU_STATUS_STOPPED_BY_STOP | SPU_STATUS_STOPPED_BY_HALT | diff --git a/arch/powerpc/platforms/cell/spufs/sched.c b/arch/powerpc/platforms/cell/spufs/sched.c index 52215aa..82ea576 100644 --- a/arch/powerpc/platforms/cell/spufs/sched.c +++ b/arch/powerpc/platforms/cell/spufs/sched.c @@ -245,7 +245,6 @@ static void spu_bind_context(struct spu *spu, struct spu_context *ctx) 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); @@ -433,7 +432,6 @@ static void spu_unbind_context(struct spu *spu, struct spu_context *ctx) spu->wbox_callback = NULL; spu->stop_callback = NULL; spu->mfc_callback = NULL; - spu->dma_callback = NULL; spu_associate_mm(spu, NULL); spu->pid = 0; spu->tgid = 0; diff --git a/arch/powerpc/platforms/cell/spufs/spufs.h b/arch/powerpc/platforms/cell/spufs/spufs.h index afdddbc..eaab1b2 100644 --- a/arch/powerpc/platforms/cell/spufs/spufs.h +++ b/arch/powerpc/platforms/cell/spufs/spufs.h @@ -222,6 +222,7 @@ void spu_gang_add_ctx(struct spu_gang *gang, struct spu_context *ctx); /* fault handling */ int spufs_handle_class1(struct spu_context *ctx); +int spufs_handle_class0(struct spu_context *ctx); /* affinity */ struct spu *affinity_check(struct spu_context *ctx); diff --git a/arch/powerpc/platforms/cell/spufs/switch.c b/arch/powerpc/platforms/cell/spufs/switch.c index c9600e8..1a7d7a0 100644 --- a/arch/powerpc/platforms/cell/spufs/switch.c +++ b/arch/powerpc/platforms/cell/spufs/switch.c @@ -2077,10 +2077,6 @@ int spu_save(struct spu_state *prev, struct spu *spu) int rc; acquire_spu_lock(spu); /* Step 1. */ - prev->dar = spu->dar; - prev->dsisr = spu->dsisr; - spu->dar = 0; - spu->dsisr = 0; rc = __do_spu_save(prev, spu); /* Steps 2-53. */ release_spu_lock(spu); if (rc != 0 && rc != 2 && rc != 6) { @@ -2107,9 +2103,6 @@ int spu_restore(struct spu_state *new, struct spu *spu) acquire_spu_lock(spu); harvest(NULL, spu); spu->slb_replace = 0; - new->dar = 0; - new->dsisr = 0; - spu->class_0_pending = 0; rc = __do_spu_restore(new, spu); release_spu_lock(spu); if (rc) { diff --git a/include/asm-powerpc/spu.h b/include/asm-powerpc/spu.h index 816e3dc..2774604 100644 --- a/include/asm-powerpc/spu.h +++ b/include/asm-powerpc/spu.h @@ -146,7 +146,6 @@ struct spu { void (* ibox_callback)(struct spu *spu); void (* stop_callback)(struct spu *spu); void (* mfc_callback)(struct spu *spu); - void (* dma_callback)(struct spu *spu, int type); char irq_c0[8]; char irq_c1[8]; @@ -197,8 +196,6 @@ struct cbe_spu_info { extern struct cbe_spu_info cbe_spu_info[]; void spu_init_channels(struct spu *spu); -int spu_irq_class_0_bottom(struct spu *spu); -int spu_irq_class_1_bottom(struct spu *spu); void spu_irq_setaffinity(struct spu *spu, int cpu); void spu_setup_kernel_slbs(struct spu *spu, struct spu_lscsa *lscsa, diff --git a/include/asm-powerpc/spu_csa.h b/include/asm-powerpc/spu_csa.h index 34da5c6..0ab6bff 100644 --- a/include/asm-powerpc/spu_csa.h +++ b/include/asm-powerpc/spu_csa.h @@ -254,7 +254,7 @@ struct spu_state { u64 spu_chnldata_RW[32]; u32 spu_mailbox_data[4]; u32 pu_mailbox_data[1]; - u64 dar, dsisr; + u64 dar, dsisr, class_0_pending; unsigned long suspend_time; spinlock_t register_lock; };