Implement sata_pmp_qc_defer_cmd_switch() - standard qc_defer for
command switching PMP support.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
drivers/ata/libata-core.c | 1 +
drivers/ata/libata-pmp.c | 30 ++++++++++++++++++++++++++++++
include/linux/libata.h | 1 +
3 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 997315c..38d7492 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -7143,6 +7143,7 @@ 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 26ff24e..add2445 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 f563301..478c3e8 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -941,6 +941,7 @@ 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);
--
1.5.0.3
-
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