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author | Ingo Molnar <mingo@elte.hu> | 2008-10-27 10:50:54 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-10-27 10:50:54 +0100 |
commit | 4944dd62de21230af039eda7cd218e9a09021d11 (patch) | |
tree | bac70f7bab8506c7e1b0408bacbdb0b1d77262e9 /arch/powerpc/platforms/cell/spufs/file.c | |
parent | f17845e5d97ead8fbdadfd40039e058ec7cf4a42 (diff) | |
parent | 0173a3265b228da319ceb9c1ec6a5682fd1b2d92 (diff) | |
download | kernel_samsung_smdk4412-4944dd62de21230af039eda7cd218e9a09021d11.zip kernel_samsung_smdk4412-4944dd62de21230af039eda7cd218e9a09021d11.tar.gz kernel_samsung_smdk4412-4944dd62de21230af039eda7cd218e9a09021d11.tar.bz2 |
Merge commit 'v2.6.28-rc2' into tracing/urgent
Diffstat (limited to 'arch/powerpc/platforms/cell/spufs/file.c')
-rw-r--r-- | arch/powerpc/platforms/cell/spufs/file.c | 155 |
1 files changed, 98 insertions, 57 deletions
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c index 010a51f..b73c369 100644 --- a/arch/powerpc/platforms/cell/spufs/file.c +++ b/arch/powerpc/platforms/cell/spufs/file.c @@ -548,6 +548,11 @@ spufs_regs_read(struct file *file, char __user *buffer, int ret; struct spu_context *ctx = file->private_data; + /* pre-check for file position: if we'd return EOF, there's no point + * causing a deschedule */ + if (*pos >= sizeof(ctx->csa.lscsa->gprs)) + return 0; + ret = spu_acquire_saved(ctx); if (ret) return ret; @@ -2426,38 +2431,49 @@ static inline int spufs_switch_log_avail(struct spu_context *ctx) static int spufs_switch_log_open(struct inode *inode, struct file *file) { struct spu_context *ctx = SPUFS_I(inode)->i_ctx; + int rc; + + rc = spu_acquire(ctx); + if (rc) + return rc; - /* - * We (ab-)use the mapping_lock here because it serves the similar - * purpose for synchronizing open/close elsewhere. Maybe it should - * be renamed eventually. - */ - mutex_lock(&ctx->mapping_lock); if (ctx->switch_log) { - spin_lock(&ctx->switch_log->lock); - ctx->switch_log->head = 0; - ctx->switch_log->tail = 0; - spin_unlock(&ctx->switch_log->lock); - } else { - /* - * We allocate the switch log data structures on first open. - * They will never be free because we assume a context will - * be traced until it goes away. - */ - ctx->switch_log = kzalloc(sizeof(struct switch_log) + - SWITCH_LOG_BUFSIZE * sizeof(struct switch_log_entry), - GFP_KERNEL); - if (!ctx->switch_log) - goto out; - spin_lock_init(&ctx->switch_log->lock); - init_waitqueue_head(&ctx->switch_log->wait); + rc = -EBUSY; + goto out; } - mutex_unlock(&ctx->mapping_lock); + + ctx->switch_log = kmalloc(sizeof(struct switch_log) + + SWITCH_LOG_BUFSIZE * sizeof(struct switch_log_entry), + GFP_KERNEL); + + if (!ctx->switch_log) { + rc = -ENOMEM; + goto out; + } + + ctx->switch_log->head = ctx->switch_log->tail = 0; + init_waitqueue_head(&ctx->switch_log->wait); + rc = 0; + +out: + spu_release(ctx); + return rc; +} + +static int spufs_switch_log_release(struct inode *inode, struct file *file) +{ + struct spu_context *ctx = SPUFS_I(inode)->i_ctx; + int rc; + + rc = spu_acquire(ctx); + if (rc) + return rc; + + kfree(ctx->switch_log); + ctx->switch_log = NULL; + spu_release(ctx); return 0; - out: - mutex_unlock(&ctx->mapping_lock); - return -ENOMEM; } static int switch_log_sprint(struct spu_context *ctx, char *tbuf, int n) @@ -2485,42 +2501,54 @@ static ssize_t spufs_switch_log_read(struct file *file, char __user *buf, if (!buf || len < 0) return -EINVAL; + error = spu_acquire(ctx); + if (error) + return error; + while (cnt < len) { char tbuf[128]; int width; - if (file->f_flags & O_NONBLOCK) { - if (spufs_switch_log_used(ctx) <= 0) - return cnt ? cnt : -EAGAIN; - } else { - /* Wait for data in buffer */ - error = wait_event_interruptible(ctx->switch_log->wait, - spufs_switch_log_used(ctx) > 0); - if (error) + if (spufs_switch_log_used(ctx) == 0) { + if (cnt > 0) { + /* If there's data ready to go, we can + * just return straight away */ + break; + + } else if (file->f_flags & O_NONBLOCK) { + error = -EAGAIN; break; - } - spin_lock(&ctx->switch_log->lock); - if (ctx->switch_log->head == ctx->switch_log->tail) { - /* multiple readers race? */ - spin_unlock(&ctx->switch_log->lock); - continue; + } else { + /* spufs_wait will drop the mutex and + * re-acquire, but since we're in read(), the + * file cannot be _released (and so + * ctx->switch_log is stable). + */ + error = spufs_wait(ctx->switch_log->wait, + spufs_switch_log_used(ctx) > 0); + + /* On error, spufs_wait returns without the + * state mutex held */ + if (error) + return error; + + /* We may have had entries read from underneath + * us while we dropped the mutex in spufs_wait, + * so re-check */ + if (spufs_switch_log_used(ctx) == 0) + continue; + } } width = switch_log_sprint(ctx, tbuf, sizeof(tbuf)); - if (width < len) { + if (width < len) ctx->switch_log->tail = (ctx->switch_log->tail + 1) % SWITCH_LOG_BUFSIZE; - } - - spin_unlock(&ctx->switch_log->lock); - - /* - * If the record is greater than space available return - * partial buffer (so far) - */ - if (width >= len) + else + /* If the record is greater than space available return + * partial buffer (so far) */ break; error = copy_to_user(buf + cnt, tbuf, width); @@ -2529,6 +2557,8 @@ static ssize_t spufs_switch_log_read(struct file *file, char __user *buf, cnt += width; } + spu_release(ctx); + return cnt == 0 ? error : cnt; } @@ -2537,29 +2567,41 @@ static unsigned int spufs_switch_log_poll(struct file *file, poll_table *wait) struct inode *inode = file->f_path.dentry->d_inode; struct spu_context *ctx = SPUFS_I(inode)->i_ctx; unsigned int mask = 0; + int rc; poll_wait(file, &ctx->switch_log->wait, wait); + rc = spu_acquire(ctx); + if (rc) + return rc; + if (spufs_switch_log_used(ctx) > 0) mask |= POLLIN; + spu_release(ctx); + return mask; } static const struct file_operations spufs_switch_log_fops = { - .owner = THIS_MODULE, - .open = spufs_switch_log_open, - .read = spufs_switch_log_read, - .poll = spufs_switch_log_poll, + .owner = THIS_MODULE, + .open = spufs_switch_log_open, + .read = spufs_switch_log_read, + .poll = spufs_switch_log_poll, + .release = spufs_switch_log_release, }; +/** + * Log a context switch event to a switch log reader. + * + * Must be called with ctx->state_mutex held. + */ void spu_switch_log_notify(struct spu *spu, struct spu_context *ctx, u32 type, u32 val) { if (!ctx->switch_log) return; - spin_lock(&ctx->switch_log->lock); if (spufs_switch_log_avail(ctx) > 1) { struct switch_log_entry *p; @@ -2573,7 +2615,6 @@ void spu_switch_log_notify(struct spu *spu, struct spu_context *ctx, ctx->switch_log->head = (ctx->switch_log->head + 1) % SWITCH_LOG_BUFSIZE; } - spin_unlock(&ctx->switch_log->lock); wake_up(&ctx->switch_log->wait); } |