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authorTejun Heo <htejun@gmail.com>2007-09-23 08:19:54 +0400
committerJeff Garzik <jeff@garzik.org>2007-10-12 22:55:44 +0400
commit31f88384443b3e0d7e2c9d36a96647b7e82edad3 (patch)
tree7bd6321d668f86adbf266513b83a75ae8d568772 /drivers/ata/libata-pmp.c
parentd0df8b5d0fb547a3351c2a4b1ded7f7cde5d713a (diff)
downloadlinux-31f88384443b3e0d7e2c9d36a96647b7e82edad3.tar.xz
libata-pmp: implement qc_defer for command switching PMP support
Implement sata_pmp_qc_defer_cmd_switch() - standard qc_defer for command switching PMP support. Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/ata/libata-pmp.c')
-rw-r--r--drivers/ata/libata-pmp.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
index eeffce636d0c..f6c4b11336e9 100644
--- a/drivers/ata/libata-pmp.c
+++ b/drivers/ata/libata-pmp.c
@@ -70,6 +70,36 @@ static int sata_pmp_write(struct ata_link *link, int reg, u32 val)
}
/**
+ * sata_pmp_qc_defer_cmd_switch - qc_defer for command switching PMP
+ * @qc: ATA command in question
+ *
+ * A host which has command switching PMP support cannot issue
+ * commands to multiple links simultaneously.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host lock)
+ *
+ * RETURNS:
+ * ATA_DEFER_* if deferring is needed, 0 otherwise.
+ */
+int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc)
+{
+ struct ata_link *link = qc->dev->link;
+ struct ata_port *ap = link->ap;
+
+ if (ap->excl_link == NULL || ap->excl_link == link) {
+ if (ap->nr_active_links == 0 || ata_link_active(link)) {
+ qc->flags |= ATA_QCFLAG_CLEAR_EXCL;
+ return ata_std_qc_defer(qc);
+ }
+
+ ap->excl_link = link;
+ }
+
+ return ATA_DEFER_PORT;
+}
+
+/**
* sata_pmp_read_init_tf - initialize TF for PMP read
* @tf: taskfile to initialize
* @dev: PMP dev