diff options
Diffstat (limited to 'arch/powerpc/platforms/cell/spufs/run.c')
| -rw-r--r-- | arch/powerpc/platforms/cell/spufs/run.c | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/run.c b/arch/powerpc/platforms/cell/spufs/run.c index 18ea8866c61..c04e078c0fe 100644 --- a/arch/powerpc/platforms/cell/spufs/run.c +++ b/arch/powerpc/platforms/cell/spufs/run.c @@ -76,6 +76,90 @@ static inline int spu_reacquire_runnable(struct spu_context *ctx, u32 *npc, return 0; } +/* + * SPU syscall restarting is tricky because we violate the basic + * assumption that the signal handler is running on the interrupted + * thread. Here instead, the handler runs on PowerPC user space code, + * while the syscall was called from the SPU. + * This means we can only do a very rough approximation of POSIX + * signal semantics. + */ +int spu_handle_restartsys(struct spu_context *ctx, long *spu_ret, + unsigned int *npc) +{ + int ret; + + switch (*spu_ret) { + case -ERESTARTSYS: + case -ERESTARTNOINTR: + /* + * Enter the regular syscall restarting for + * sys_spu_run, then restart the SPU syscall + * callback. + */ + *npc -= 8; + ret = -ERESTARTSYS; + break; + case -ERESTARTNOHAND: + case -ERESTART_RESTARTBLOCK: + /* + * Restart block is too hard for now, just return -EINTR + * to the SPU. + * ERESTARTNOHAND comes from sys_pause, we also return + * -EINTR from there. + * Assume that we need to be restarted ourselves though. + */ + *spu_ret = -EINTR; + ret = -ERESTARTSYS; + break; + default: + printk(KERN_WARNING "%s: unexpected return code %ld\n", + __FUNCTION__, *spu_ret); + ret = 0; + } + return ret; +} + +int spu_process_callback(struct spu_context *ctx) +{ + struct spu_syscall_block s; + u32 ls_pointer, npc; + char *ls; + long spu_ret; + int ret; + + /* get syscall block from local store */ + npc = ctx->ops->npc_read(ctx); + ls = ctx->ops->get_ls(ctx); + ls_pointer = *(u32*)(ls + npc); + if (ls_pointer > (LS_SIZE - sizeof(s))) + return -EFAULT; + memcpy(&s, ls + ls_pointer, sizeof (s)); + + /* do actual syscall without pinning the spu */ + ret = 0; + spu_ret = -ENOSYS; + npc += 4; + + if (s.nr_ret < __NR_syscalls) { + spu_release(ctx); + /* do actual system call from here */ + spu_ret = spu_sys_callback(&s); + if (spu_ret <= -ERESTARTSYS) { + ret = spu_handle_restartsys(ctx, &spu_ret, &npc); + } + spu_acquire(ctx); + if (ret == -ERESTARTSYS) + return ret; + } + + /* write result, jump over indirect pointer */ + memcpy(ls + ls_pointer, &spu_ret, sizeof (spu_ret)); + ctx->ops->npc_write(ctx, npc); + ctx->ops->runcntl_write(ctx, SPU_RUNCNTL_RUNNABLE); + return ret; +} + static inline int spu_process_events(struct spu_context *ctx) { struct spu *spu = ctx->spu; @@ -107,6 +191,13 @@ long spufs_run_spu(struct file *file, struct spu_context *ctx, ret = spufs_wait(ctx->stop_wq, spu_stopped(ctx, status)); if (unlikely(ret)) break; + if ((*status & SPU_STATUS_STOPPED_BY_STOP) && + (*status >> SPU_STOP_STATUS_SHIFT == 0x2104)) { + ret = spu_process_callback(ctx); + if (ret) + break; + *status &= ~SPU_STATUS_STOPPED_BY_STOP; + } if (unlikely(ctx->state != SPU_STATE_RUNNABLE)) { ret = spu_reacquire_runnable(ctx, npc, status); if (ret) |