From a2a7a662f80d8b7f2295a36de1f9b033ed0b910c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 13 Dec 2005 14:48:31 +0900 Subject: [PATCH] [PATCH] libata: implement ata_exec_internal() This patch implements ata_exec_internal() function which performs libata internal command execution. Previously, this was done by each user by manually initializing a qc, issueing it, waiting for its completion and handling errors. In addition to obvious code factoring, using ata_exec_internal() fixes the following bugs. * qc not freed on issue failure * ap->qactive clearing could race with the next internal command * race between timeout handling and irq * ignoring error condition not represented in tf->status Also, qc & hardware are not accessed anymore once it's completed, making internal commands more conformant with general semantics. ata_exec_internal() also makes it easy to issue internal commands from multiple threads if that becomes necessary. This patch only implements ata_exec_internal(). A following patch will convert all users. Signed-off-by: Tejun Heo -- Jeff, all patches have been regenerated against upstream branch as of today. (575ab52a218e4ff0667a6cbd972c3af443ee8713) Also, I took out a debug printk from ata_exec_internal (don't know how that one got left there). Other than that, all patches are identical to the previous posting. Thanks. :-) Signed-off-by: Jeff Garzik --- drivers/scsi/libata-core.c | 99 ++++++++++++++++++++++++++++++++++++++ include/linux/libata.h | 2 + 2 files changed, 101 insertions(+) diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index a0060cf31e0d..de80abeab065 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -1046,6 +1046,105 @@ static unsigned int ata_pio_modes(const struct ata_device *adev) return modes; } +struct ata_exec_internal_arg { + unsigned int err_mask; + struct ata_taskfile *tf; + struct completion *waiting; +}; + +int ata_qc_complete_internal(struct ata_queued_cmd *qc) +{ + struct ata_exec_internal_arg *arg = qc->private_data; + struct completion *waiting = arg->waiting; + + if (!(qc->err_mask & ~AC_ERR_DEV)) + qc->ap->ops->tf_read(qc->ap, arg->tf); + arg->err_mask = qc->err_mask; + arg->waiting = NULL; + complete(waiting); + + return 0; +} + +/** + * ata_exec_internal - execute libata internal command + * @ap: Port to which the command is sent + * @dev: Device to which the command is sent + * @tf: Taskfile registers for the command and the result + * @dma_dir: Data tranfer direction of the command + * @buf: Data buffer of the command + * @buflen: Length of data buffer + * + * Executes libata internal command with timeout. @tf contains + * command on entry and result on return. Timeout and error + * conditions are reported via return value. No recovery action + * is taken after a command times out. It's caller's duty to + * clean up after timeout. + * + * LOCKING: + * None. Should be called with kernel context, might sleep. + */ + +static unsigned +ata_exec_internal(struct ata_port *ap, struct ata_device *dev, + struct ata_taskfile *tf, + int dma_dir, void *buf, unsigned int buflen) +{ + u8 command = tf->command; + struct ata_queued_cmd *qc; + DECLARE_COMPLETION(wait); + unsigned long flags; + struct ata_exec_internal_arg arg; + + spin_lock_irqsave(&ap->host_set->lock, flags); + + qc = ata_qc_new_init(ap, dev); + BUG_ON(qc == NULL); + + qc->tf = *tf; + qc->dma_dir = dma_dir; + if (dma_dir != DMA_NONE) { + ata_sg_init_one(qc, buf, buflen); + qc->nsect = buflen / ATA_SECT_SIZE; + } + + arg.waiting = &wait; + arg.tf = tf; + qc->private_data = &arg; + qc->complete_fn = ata_qc_complete_internal; + + if (ata_qc_issue(qc)) + goto issue_fail; + + spin_unlock_irqrestore(&ap->host_set->lock, flags); + + if (!wait_for_completion_timeout(&wait, ATA_TMOUT_INTERNAL)) { + spin_lock_irqsave(&ap->host_set->lock, flags); + + /* We're racing with irq here. If we lose, the + * following test prevents us from completing the qc + * again. If completion irq occurs after here but + * before the caller cleans up, it will result in a + * spurious interrupt. We can live with that. + */ + if (arg.waiting) { + qc->err_mask = AC_ERR_OTHER; + ata_qc_complete(qc); + printk(KERN_WARNING "ata%u: qc timeout (cmd 0x%x)\n", + ap->id, command); + } + + spin_unlock_irqrestore(&ap->host_set->lock, flags); + } + + return arg.err_mask; + + issue_fail: + ata_qc_free(qc); + spin_unlock_irqrestore(&ap->host_set->lock, flags); + return AC_ERR_OTHER; +} + static int ata_qc_wait_err(struct ata_queued_cmd *qc, struct completion *wait) { diff --git a/include/linux/libata.h b/include/linux/libata.h index e18ce039cdfd..833e57afd54c 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -135,6 +135,8 @@ enum { ATA_TMOUT_BOOT_QUICK = 7 * HZ, /* hueristic */ ATA_TMOUT_CDB = 30 * HZ, ATA_TMOUT_CDB_QUICK = 5 * HZ, + ATA_TMOUT_INTERNAL = 30 * HZ, + ATA_TMOUT_INTERNAL_QUICK = 5 * HZ, /* ATA bus states */ BUS_UNKNOWN = 0, -- GitLab