From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: [PATCH 5/8] libata-pmp: implement qc_defer for command switching PMP support Date: Mon, 16 Jul 2007 18:46:04 +0900 Message-ID: <1184579164253-git-send-email-htejun@gmail.com> References: <1184579163885-git-send-email-htejun@gmail.com> Reply-To: Tejun Heo Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Return-path: Received: from nz-out-0506.google.com ([64.233.162.238]:53749 "EHLO nz-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757506AbXGPJqS (ORCPT ); Mon, 16 Jul 2007 05:46:18 -0400 Received: by nz-out-0506.google.com with SMTP id s18so784877nze for ; Mon, 16 Jul 2007 02:46:17 -0700 (PDT) In-Reply-To: <1184579163885-git-send-email-htejun@gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik , Alan Cox , linux-ide@vger.kernel.org, Forrest Zhao Cc: Tejun Heo Implement sata_pmp_qc_defer_cmd_switch() - standard qc_defer for command switching PMP support. Signed-off-by: Tejun Heo --- 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