Commit 31f88384 authored by Tejun Heo's avatar Tejun Heo Committed by Jeff Garzik
Browse files

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: default avatarTejun Heo <htejun@gmail.com>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent d0df8b5d

drivers/ata/libata-core.c

+1 −0
Original line number Diff line number Diff line
@@ -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);

drivers/ata/libata-pmp.c

+30 −0
Original line number Diff line number Diff line
@@ -69,6 +69,36 @@ static int sata_pmp_write(struct ata_link *link, int reg, u32 val) 
	return rc;

}



/**

 *	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

include/linux/libata.h

+1 −0
Original line number Diff line number Diff line
@@ -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);