aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorTejun Heo <htejun@gmail.com>2007-09-23 13:19:54 +0900
committerJeff Garzik <jeff@garzik.org>2007-10-12 14:55:44 -0400
commit31f88384443b3e0d7e2c9d36a96647b7e82edad3 (patch)
tree7bd6321d668f86adbf266513b83a75ae8d568772
parentd0df8b5d0fb547a3351c2a4b1ded7f7cde5d713a (diff)
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>
-rw-r--r--drivers/ata/libata-core.c1
-rw-r--r--drivers/ata/libata-pmp.c30
-rw-r--r--include/linux/libata.h1
3 files changed, 32 insertions, 0 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index d3e78d97529..5532a6564d0 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -7303,6 +7303,7 @@ EXPORT_SYMBOL_GPL(ata_pci_default_filter);
EXPORT_SYMBOL_GPL(ata_pci_clear_simplex);
#endif /* CONFIG_PCI */
+EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
EXPORT_SYMBOL_GPL(sata_pmp_read_init_tf);
EXPORT_SYMBOL_GPL(sata_pmp_read_val);
EXPORT_SYMBOL_GPL(sata_pmp_write_init_tf);
diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
index eeffce636d0..f6c4b11336e 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
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 3cfdb5f6762..ca296a575c4 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -947,6 +947,7 @@ extern unsigned long ata_pci_default_filter(struct ata_device *, unsigned long);
/*
* PMP
*/
+extern int sata_pmp_qc_defer_cmd_switch(struct ata_queued_cmd *qc);
extern void sata_pmp_read_init_tf(struct ata_taskfile *tf,
struct ata_device *dev, int pmp, int reg);
extern u32 sata_pmp_read_val(const struct ata_taskfile *tf);