diff options
| author | Tejun Heo <htejun@gmail.com> | 2007-09-23 13:19:54 +0900 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2007-10-12 14:55:44 -0400 |
| commit | 31f88384443b3e0d7e2c9d36a96647b7e82edad3 (patch) | |
| tree | 7bd6321d668f86adbf266513b83a75ae8d568772 | |
| parent | d0df8b5d0fb547a3351c2a4b1ded7f7cde5d713a (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.c | 1 | ||||
| -rw-r--r-- | drivers/ata/libata-pmp.c | 30 | ||||
| -rw-r--r-- | 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 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); |