From 34bf21704c848fe00c516d1c8f163db08b70b137 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Mon, 15 May 2006 20:57:46 +0900 Subject: [PATCH] [PATCH] libata: implement new SCR handling and port on/offline functions Implement ata_scr_{valid|read|write|write_flush}() and ata_port_{online|offline}(). These functions replace scr_{read|write}() and sata_dev_present(). Major difference between between the new SCR functions and the old ones is that the new ones have a way to signal error to the caller. This makes handling SCR-available and SCR-unavailable cases in the same path easier. Also, it eases later PM implementation where SCR access can fail due to various reasons. ata_port_{online|offline}() functions return 1 only when they are affirmitive of the condition. e.g. if SCR is unaccessible or presence cannot be determined for other reasons, these functions return 0. So, ata_port_online() != !ata_port_offline(). This distinction is useful in many exception handling cases. Signed-off-by: Tejun Heo --- drivers/scsi/libata-core.c | 143 +++++++++++++++++++++++++++++++++++++ include/linux/libata.h | 6 ++ 2 files changed, 149 insertions(+) diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index f29d43cb6991..b9c5cbf0b786 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -4365,6 +4365,143 @@ irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs) return IRQ_RETVAL(handled); } +/** + * sata_scr_valid - test whether SCRs are accessible + * @ap: ATA port to test SCR accessibility for + * + * Test whether SCRs are accessible for @ap. + * + * LOCKING: + * None. + * + * RETURNS: + * 1 if SCRs are accessible, 0 otherwise. + */ +int sata_scr_valid(struct ata_port *ap) +{ + return ap->cbl == ATA_CBL_SATA && ap->ops->scr_read; +} + +/** + * sata_scr_read - read SCR register of the specified port + * @ap: ATA port to read SCR for + * @reg: SCR to read + * @val: Place to store read value + * + * Read SCR register @reg of @ap into *@val. This function is + * guaranteed to succeed if the cable type of the port is SATA + * and the port implements ->scr_read. + * + * LOCKING: + * None. + * + * RETURNS: + * 0 on success, negative errno on failure. + */ +int sata_scr_read(struct ata_port *ap, int reg, u32 *val) +{ + if (sata_scr_valid(ap)) { + *val = ap->ops->scr_read(ap, reg); + return 0; + } + return -EOPNOTSUPP; +} + +/** + * sata_scr_write - write SCR register of the specified port + * @ap: ATA port to write SCR for + * @reg: SCR to write + * @val: value to write + * + * Write @val to SCR register @reg of @ap. This function is + * guaranteed to succeed if the cable type of the port is SATA + * and the port implements ->scr_read. + * + * LOCKING: + * None. + * + * RETURNS: + * 0 on success, negative errno on failure. + */ +int sata_scr_write(struct ata_port *ap, int reg, u32 val) +{ + if (sata_scr_valid(ap)) { + ap->ops->scr_write(ap, reg, val); + return 0; + } + return -EOPNOTSUPP; +} + +/** + * sata_scr_write_flush - write SCR register of the specified port and flush + * @ap: ATA port to write SCR for + * @reg: SCR to write + * @val: value to write + * + * This function is identical to sata_scr_write() except that this + * function performs flush after writing to the register. + * + * LOCKING: + * None. + * + * RETURNS: + * 0 on success, negative errno on failure. + */ +int sata_scr_write_flush(struct ata_port *ap, int reg, u32 val) +{ + if (sata_scr_valid(ap)) { + ap->ops->scr_write(ap, reg, val); + ap->ops->scr_read(ap, reg); + return 0; + } + return -EOPNOTSUPP; +} + +/** + * ata_port_online - test whether the given port is online + * @ap: ATA port to test + * + * Test whether @ap is online. Note that this function returns 0 + * if online status of @ap cannot be obtained, so + * ata_port_online(ap) != !ata_port_offline(ap). + * + * LOCKING: + * None. + * + * RETURNS: + * 1 if the port online status is available and online. + */ +int ata_port_online(struct ata_port *ap) +{ + u32 sstatus; + + if (!sata_scr_read(ap, SCR_STATUS, &sstatus) && (sstatus & 0xf) == 0x3) + return 1; + return 0; +} + +/** + * ata_port_offline - test whether the given port is offline + * @ap: ATA port to test + * + * Test whether @ap is offline. Note that this function returns + * 0 if offline status of @ap cannot be obtained, so + * ata_port_online(ap) != !ata_port_offline(ap). + * + * LOCKING: + * None. + * + * RETURNS: + * 1 if the port offline status is available and offline. + */ +int ata_port_offline(struct ata_port *ap) +{ + u32 sstatus; + + if (!sata_scr_read(ap, SCR_STATUS, &sstatus) && (sstatus & 0xf) != 0x3) + return 1; + return 0; +} /* * Execute a 'simple' command, that only consists of the opcode 'cmd' itself, @@ -5133,6 +5270,12 @@ EXPORT_SYMBOL_GPL(ata_scsi_queuecmd); EXPORT_SYMBOL_GPL(ata_scsi_slave_config); EXPORT_SYMBOL_GPL(ata_scsi_release); EXPORT_SYMBOL_GPL(ata_host_intr); +EXPORT_SYMBOL_GPL(sata_scr_valid); +EXPORT_SYMBOL_GPL(sata_scr_read); +EXPORT_SYMBOL_GPL(sata_scr_write); +EXPORT_SYMBOL_GPL(sata_scr_write_flush); +EXPORT_SYMBOL_GPL(ata_port_online); +EXPORT_SYMBOL_GPL(ata_port_offline); EXPORT_SYMBOL_GPL(ata_id_string); EXPORT_SYMBOL_GPL(ata_id_c_string); EXPORT_SYMBOL_GPL(ata_scsi_simulate); diff --git a/include/linux/libata.h b/include/linux/libata.h index a4b8a419caad..47b97157995d 100644 --- a/include/linux/libata.h +++ b/include/linux/libata.h @@ -536,6 +536,12 @@ extern int ata_scsi_ioctl(struct scsi_device *dev, int cmd, void __user *arg); extern int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *)); extern int ata_scsi_release(struct Scsi_Host *host); extern unsigned int ata_host_intr(struct ata_port *ap, struct ata_queued_cmd *qc); +extern int sata_scr_valid(struct ata_port *ap); +extern int sata_scr_read(struct ata_port *ap, int reg, u32 *val); +extern int sata_scr_write(struct ata_port *ap, int reg, u32 val); +extern int sata_scr_write_flush(struct ata_port *ap, int reg, u32 val); +extern int ata_port_online(struct ata_port *ap); +extern int ata_port_offline(struct ata_port *ap); extern int ata_scsi_device_resume(struct scsi_device *); extern int ata_scsi_device_suspend(struct scsi_device *, pm_message_t state); extern int ata_device_resume(struct ata_port *, struct ata_device *); -- 2.30.2