From 2ab7db1ff1d64a2ba389d0692d532f42a15f1f72 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 15 May 2006 20:58:02 +0900 Subject: [PATCH] [PATCH] libata-eh-fw: use special reserved tag and qc for internal commands New EH may issue internal commands to recover from error while failed qc's are still hanging around. To allow such usage, reserve tag ATA_MAX_QUEUE-1 for internal command. This also makes it easy to tell whether a qc is for internal command or not. ata_tag_internal() test implements this test. To avoid breaking existing drivers, ata_exec_internal() uses ATA_TAG_INTERNAL only for drivers which implement ->error_handler. For drivers using old EH, tag 0 is used. Note that this makes ata_tag_internal() test valid only when ->error_handler is implemented. This is okay as drivers on old EH should not and does not have any reason to use ata_tag_internal(). Signed-off-by: Tejun Heo --- drivers/scsi/libata-core.c | 32 +++++++++++++++++++++++++++++--- include/linux/libata.h | 9 ++++++++- 2 files changed, 37 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index de2cd61a264d..966abb5f423e 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -980,15 +980,39 @@ unsigned ata_exec_internal(struct ata_device *dev, struct ata_port *ap = dev->ap; u8 command = tf->command; struct ata_queued_cmd *qc; + unsigned int tag, preempted_tag; DECLARE_COMPLETION(wait); unsigned long flags; unsigned int err_mask; spin_lock_irqsave(&ap->host_set->lock, flags); - qc = ata_qc_new_init(dev); - BUG_ON(qc == NULL); + /* initialize internal qc */ + /* XXX: Tag 0 is used for drivers with legacy EH as some + * drivers choke if any other tag is given. This breaks + * ata_tag_internal() test for those drivers. Don't use new + * EH stuff without converting to it. + */ + if (ap->ops->error_handler) + tag = ATA_TAG_INTERNAL; + else + tag = 0; + + if (test_and_set_bit(tag, &ap->qactive)) + BUG(); + qc = ata_qc_from_tag(ap, tag); + + qc->tag = tag; + qc->scsicmd = NULL; + qc->ap = ap; + qc->dev = dev; + ata_qc_reinit(qc); + + preempted_tag = ap->active_tag; + ap->active_tag = ATA_TAG_POISON; + + /* prepare & issue qc */ qc->tf = *tf; if (cdb) memcpy(qc->cdb, cdb, ATAPI_CDB_LEN); @@ -1035,6 +1059,7 @@ unsigned ata_exec_internal(struct ata_device *dev, err_mask = qc->err_mask; ata_qc_free(qc); + ap->active_tag = preempted_tag; /* XXX - Some LLDDs (sata_mv) disable port on command failure. * Until those drivers are fixed, we detect the condition @@ -4014,7 +4039,8 @@ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap) struct ata_queued_cmd *qc = NULL; unsigned int i; - for (i = 0; i < ATA_MAX_QUEUE; i++) + /* the last tag is reserved for internal command. */ + for (i = 0; i < ATA_MAX_QUEUE - 1; i++) if (!test_and_set_bit(i, &ap->qactive)) { qc = ata_qc_from_tag(ap, i); break; diff --git a/include/linux/libata.h b/include/linux/libata.h index e5d6d7f8e6dc..5a403e434ff8 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -108,7 +108,9 @@ enum { LIBATA_MAX_PRD = ATA_MAX_PRD / 2, ATA_MAX_PORTS = 8, ATA_DEF_QUEUE = 1, - ATA_MAX_QUEUE = 1, + /* tag ATA_MAX_QUEUE - 1 is reserved for internal commands */ + ATA_MAX_QUEUE = 2, + ATA_TAG_INTERNAL = ATA_MAX_QUEUE - 1, ATA_MAX_SECTORS = 200, /* FIXME */ ATA_MAX_BUS = 2, ATA_DEF_BUSY_WAIT = 10000, @@ -717,6 +719,11 @@ static inline unsigned int ata_tag_valid(unsigned int tag) return (tag < ATA_MAX_QUEUE) ? 1 : 0; } +static inline unsigned int ata_tag_internal(unsigned int tag) +{ + return tag == ATA_MAX_QUEUE - 1; +} + static inline unsigned int ata_class_enabled(unsigned int class) { return class == ATA_DEV_ATA || class == ATA_DEV_ATAPI; -- 2.11.4.GIT