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author | Arnd Bergmann <arnd@arndb.de> | 2005-12-05 22:52:25 -0500 |
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committer | Paul Mackerras <paulus@samba.org> | 2006-01-09 14:52:55 +1100 |
commit | 5110459f181ef1f11200bb3dec61953f08cc49e7 (patch) | |
tree | 73356ce50b3fb5055b4a6f39f237f046615f797d /arch/powerpc/platforms/cell/spufs/file.c | |
parent | 3b3d22cb84a0bb12f6bbb2b1158972894bec3f21 (diff) | |
download | op-kernel-dev-5110459f181ef1f11200bb3dec61953f08cc49e7.zip op-kernel-dev-5110459f181ef1f11200bb3dec61953f08cc49e7.tar.gz |
[PATCH] spufs: Improved SPU preemptability.
This patch makes it easier to preempt an SPU context by
having the scheduler hold ctx->state_sema for much shorter
periods of time.
As part of this restructuring, the control logic for the "run"
operation is moved from arch/ppc64/kernel/spu_base.c to
fs/spufs/file.c. Of course the base retains "bottom half"
handlers for class{0,1} irqs. The new run loop will re-acquire
an SPU if preempted.
From: Mark Nutter <mnutter@us.ibm.com>
Signed-off-by: Arnd Bergmann <arndb@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/platforms/cell/spufs/file.c')
-rw-r--r-- | arch/powerpc/platforms/cell/spufs/file.c | 117 |
1 files changed, 107 insertions, 10 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c index 0fe1fec..af5adc3 100644 --- a/arch/powerpc/platforms/cell/spufs/file.c +++ b/arch/powerpc/platforms/cell/spufs/file.c @@ -25,6 +25,7 @@ #include <linux/module.h> #include <linux/pagemap.h> #include <linux/poll.h> +#include <linux/ptrace.h> #include <asm/io.h> #include <asm/semaphore.h> @@ -540,26 +541,122 @@ static struct file_operations spufs_wbox_stat_fops = { .read = spufs_wbox_stat_read, }; -long spufs_run_spu(struct file *file, struct spu_context *ctx, - u32 *npc, u32 *status) +/* interrupt-level stop callback function. */ +void spufs_stop_callback(struct spu *spu) +{ + struct spu_context *ctx = spu->ctx; + + wake_up_all(&ctx->stop_wq); +} + +static inline int spu_stopped(struct spu_context *ctx, u32 * stat) +{ + struct spu *spu; + u64 pte_fault; + + *stat = ctx->ops->status_read(ctx); + if (ctx->state != SPU_STATE_RUNNABLE) + return 1; + spu = ctx->spu; + pte_fault = spu->dsisr & + (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED); + return (!(*stat & 0x1) || pte_fault || spu->class_0_pending) ? 1 : 0; +} + +static inline int spu_run_init(struct spu_context *ctx, u32 * npc, + u32 * status) { int ret; - ret = spu_acquire_runnable(ctx); - if (ret) + if ((ret = spu_acquire_runnable(ctx)) != 0) return ret; - ctx->ops->npc_write(ctx, *npc); + ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE); + return 0; +} - ret = spu_run(ctx->spu); - - if (!ret) - ret = ctx->ops->status_read(ctx); +static inline int spu_run_fini(struct spu_context *ctx, u32 * npc, + u32 * status) +{ + int ret = 0; + *status = ctx->ops->status_read(ctx); *npc = ctx->ops->npc_read(ctx); - spu_release(ctx); + + if (signal_pending(current)) + ret = -ERESTARTSYS; + if (unlikely(current->ptrace & PT_PTRACED)) { + if ((*status & SPU_STATUS_STOPPED_BY_STOP) + && (*status >> SPU_STOP_STATUS_SHIFT) == 0x3fff) { + force_sig(SIGTRAP, current); + ret = -ERESTARTSYS; + } + } + return ret; +} + +static inline int spu_reacquire_runnable(struct spu_context *ctx, u32 *npc, + u32 *status) +{ + int ret; + + if ((ret = spu_run_fini(ctx, npc, status)) != 0) + return ret; + if (*status & (SPU_STATUS_STOPPED_BY_STOP | + SPU_STATUS_STOPPED_BY_HALT)) { + return *status; + } + if ((ret = spu_run_init(ctx, npc, status)) != 0) + return ret; + return 0; +} + +static inline int spu_process_events(struct spu_context *ctx) +{ + struct spu *spu = ctx->spu; + u64 pte_fault = MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED; + int ret = 0; + + if (spu->dsisr & pte_fault) + ret = spu_irq_class_1_bottom(spu); + 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 file *file, struct spu_context *ctx, + u32 * npc, u32 * status) +{ + int ret; + + if ((ret = spu_run_init(ctx, npc, status)) != 0) + return ret; + + do { + ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, status)); + if (unlikely(ret)) + break; + if (unlikely(ctx->state != SPU_STATE_RUNNABLE)) { + ret = spu_reacquire_runnable(ctx, npc, status); + if (ret) { + return ret; + } + continue; + } + ret = spu_process_events(ctx); + + } while (!ret && !(*status & (SPU_STATUS_STOPPED_BY_STOP | + SPU_STATUS_STOPPED_BY_HALT))); + + ctx->ops->runcntl_stop(ctx); + ret = spu_run_fini(ctx, npc, status); + if (!ret) + ret = *status; spu_yield(ctx); + return ret; } |