[PATCH 01/12] libata-hp-prep: add flags and eh_info/context fields for hotplug

[PATCH 01/12] libata-hp-prep: add flags and eh_info/context fields for hotplug

[Tejun Heo]

Add hotplug related flags and eh_info/context fields.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 include/linux/libata.h |   19 ++++++++++++++++++-
 1 files changed, 18 insertions(+), 1 deletions(-)

5577bff1743157fb00b7499d832dd55c47245e3e
diff --git a/include/linux/libata.h b/include/linux/libata.h
index b0ee1c1..4f67c43 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -131,6 +131,9 @@ enum {
 
 	ATA_DFLAG_PIO		= (1 << 8), /* device currently in PIO mode */
 
+	ATA_DFLAG_DETACH	= (1 << 16),
+	ATA_DFLAG_DETACHED	= (1 << 17),
+
 	ATA_DEV_UNKNOWN		= 0,	/* unknown device */
 	ATA_DEV_ATA		= 1,	/* ATA device */
 	ATA_DEV_ATA_UNSUP	= 2,	/* ATA device (unsupported) */
@@ -152,6 +155,9 @@ enum {
 	ATA_FLAG_PIO_POLLING	= (1 << 10), /* use polling PIO if LLD
 					      * doesn't handle PIO interrupts */
 	ATA_FLAG_NCQ		= (1 << 11), /* host supports NCQ */
+	ATA_FLAG_HRST_TO_RESUME	= (1 << 12), /* hardreset to resume phy */
+	ATA_FLAG_SKIP_D2H_BSY	= (1 << 13), /* can't wait for the first D2H
+					      * Register FIS clearing BSY */
 
 	ATA_FLAG_DEBUGMSG	= (1 << 14),
 	ATA_FLAG_FLUSH_PORT_TASK = (1 << 15), /* flush port task */
@@ -159,6 +165,9 @@ enum {
 	ATA_FLAG_EH_PENDING	= (1 << 16), /* EH pending */
 	ATA_FLAG_FROZEN		= (1 << 17), /* port is frozen */
 	ATA_FLAG_RECOVERED	= (1 << 18), /* recovery action performed */
+	ATA_FLAG_LOADING	= (1 << 19), /* boot/loading probe */
+	ATA_FLAG_UNLOADING	= (1 << 20), /* module is unloading */
+	ATA_FLAG_SCSI_HOTPLUG	= (1 << 21), /* SCSI hotplug scheduled */
 
 	ATA_FLAG_DISABLED	= (1 << 22), /* port is disabled, ignore it */
 	ATA_FLAG_SUSPENDED	= (1 << 23), /* port is suspended (power) */
@@ -240,7 +249,9 @@ enum {
 	ATA_EH_RESET_MASK	= ATA_EH_SOFTRESET | ATA_EH_HARDRESET,
 
 	/* ata_eh_info->flags */
-	ATA_EHI_DID_RESET	= (1 << 0), /* already reset this port */
+	ATA_EHI_HOTPLUGGED	= (1 << 0),  /* could have been hotplugged */
+
+	ATA_EHI_DID_RESET	= (1 << 16), /* already reset this port */
 
 	/* max repeat if error condition is still set after ->error_handler */
 	ATA_EH_MAX_REPEAT	= 5,
@@ -433,6 +444,10 @@ struct ata_eh_info {
 	unsigned int		err_mask;	/* port-wide err_mask */
 	unsigned int		action;		/* ATA_EH_* action mask */
 	unsigned int		flags;		/* ATA_EHI_* flags */
+
+	unsigned long		hotplug_timestamp;
+	unsigned int		probe_mask;
+
 	char			desc[ATA_EH_DESC_LEN];
 	int			desc_len;
 };
@@ -440,6 +455,8 @@ struct ata_eh_info {
 struct ata_eh_context {
 	struct ata_eh_info	i;
 	int			tries[ATA_MAX_DEVICES];
+	unsigned int		classes[ATA_MAX_DEVICES];
+	unsigned int		did_probe_mask;
 };
 
 struct ata_port {
-- 
1.3.2

[PATCHSET 01/03] prep for hotplug support, take 5

[Tejun Heo]

Hello,

This is part of patchset series described in [T].

This is the fourth take of add-hotplug-support patchset.  Changes from
the last take[L] are.

* ata_scsi_wq renamed to ata_aux_wq

* msleep(200) added between phy wakeup and the first SStatus polling.

* SLAVE_POSS check dropped from ata_find_dev()

* s/FIS34/D2H FIS/g

This patchset is against

  upstream (ef2824073fba9def3cf122e89cc485f66dd71f70)
  + [1] set-PIO-0-after-successful-EH-reset
  + [2] shift-host-flag-constants
  + [3] implement-ata_eh_wait

Thanks.

--
tejun

[T] http://article.gmane.org/gmane.linux.ide/11012
[L] http://article.gmane.org/gmane.linux.ide/10892
[1] http://article.gmane.org/gmane.linux.ide/10890
[2] http://article.gmane.org/gmane.linux.ide/11010
[3] http://article.gmane.org/gmane.linux.ide/11011

[PATCH 02/12] libata-hp-prep: implement ata_dev_init()

[Tejun Heo]

Move initialization of struct ata_device into ata_dev_init() in
preparation for hotplug.  This patch calls ata_dev_init() from
ata_host_init() and thus makes no functional difference.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-core.c |   26 +++++++++++++++++++++-----
 drivers/scsi/libata.h      |    1 +
 2 files changed, 22 insertions(+), 5 deletions(-)

3ef3b43d5633d30fa3f033f62094ec2e9c5b8376
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 66df895..8fda822 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -5142,6 +5142,26 @@ static void ata_host_remove(struct ata_p
 }
 
 /**
+ *	ata_dev_init - Initialize an ata_device structure
+ *	@dev: Device structure to initialize
+ *
+ *	Initialize @dev in preparation for probing.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+void ata_dev_init(struct ata_device *dev)
+{
+	struct ata_port *ap = dev->ap;
+
+	memset((void *)dev, 0, sizeof(*dev));
+	dev->devno = dev - ap->device;
+	dev->pio_mask = UINT_MAX;
+	dev->mwdma_mask = UINT_MAX;
+	dev->udma_mask = UINT_MAX;
+}
+
+/**
  *	ata_host_init - Initialize an ata_port structure
  *	@ap: Structure to initialize
  *	@host: associated SCSI mid-layer structure
@@ -5155,7 +5175,6 @@ static void ata_host_remove(struct ata_p
  *	LOCKING:
  *	Inherited from caller.
  */
-
 static void ata_host_init(struct ata_port *ap, struct Scsi_Host *host,
 			  struct ata_host_set *host_set,
 			  const struct ata_probe_ent *ent, unsigned int port_no)
@@ -5199,10 +5218,7 @@ static void ata_host_init(struct ata_por
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
 		struct ata_device *dev = &ap->device[i];
 		dev->ap = ap;
-		dev->devno = i;
-		dev->pio_mask = UINT_MAX;
-		dev->mwdma_mask = UINT_MAX;
-		dev->udma_mask = UINT_MAX;
+		ata_dev_init(dev);
 	}
 
 #ifdef ATA_IRQ_TRAP
diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index d56d9e1..c2b1c91 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -62,6 +62,7 @@ extern int ata_check_atapi_dma(struct at
 extern void ata_dev_select(struct ata_port *ap, unsigned int device,
                            unsigned int wait, unsigned int can_sleep);
 extern void swap_buf_le16(u16 *buf, unsigned int buf_words);
+extern void ata_dev_init(struct ata_device *dev);
 extern int ata_task_ioctl(struct scsi_device *scsidev, void __user *arg);
 extern int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg);
 
-- 
1.3.2

[PATCH 04/12] libata-hp-prep: update ata_scsi_find_dev() and friends

[Tejun Heo]

Separate out ata_find_dev() and __ata_scsi_find_dev() from
ata_scsi_find_dev().  These will be used by later hotplug
implementation.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-scsi.c |   40 +++++++++++++++++++++++++---------------
 1 files changed, 25 insertions(+), 15 deletions(-)

ab5b3a5b2d887ce63f8c6a7fcb9f5c07ca4b4d43
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 9e5cb9f..b45b8b3 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -52,8 +52,12 @@ #include "libata.h"
 #define SECTOR_SIZE	512
 
 typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc, const u8 *scsicmd);
-static struct ata_device *
-ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device *scsidev);
+
+static struct ata_device * __ata_scsi_find_dev(struct ata_port *ap,
+					const struct scsi_device *scsidev);
+static struct ata_device * ata_scsi_find_dev(struct ata_port *ap,
+					    const struct scsi_device *scsidev);
+
 
 #define RW_RECOVERY_MPAGE 0x1
 #define RW_RECOVERY_MPAGE_LEN 12
@@ -2308,6 +2312,23 @@ static unsigned int atapi_xlat(struct at
 	return 0;
 }
 
+static struct ata_device * ata_find_dev(struct ata_port *ap, int id)
+{
+	if (likely(id < ATA_MAX_DEVICES))
+		return &ap->device[id];
+	return NULL;
+}
+
+static struct ata_device * __ata_scsi_find_dev(struct ata_port *ap,
+					const struct scsi_device *scsidev)
+{
+	/* skip commands not addressed to targets we simulate */
+	if (unlikely(scsidev->channel || scsidev->lun))
+		return NULL;
+
+	return ata_find_dev(ap, scsidev->id);
+}
+
 /**
  *	ata_scsi_find_dev - lookup ata_device from scsi_cmnd
  *	@ap: ATA port to which the device is attached
@@ -2324,23 +2345,12 @@ static unsigned int atapi_xlat(struct at
  *	RETURNS:
  *	Associated ATA device, or %NULL if not found.
  */
-
 static struct ata_device *
 ata_scsi_find_dev(struct ata_port *ap, const struct scsi_device *scsidev)
 {
-	struct ata_device *dev;
-
-	/* skip commands not addressed to targets we simulate */
-	if (likely(scsidev->id < ATA_MAX_DEVICES))
-		dev = &ap->device[scsidev->id];
-	else
-		return NULL;
-
-	if (unlikely((scsidev->channel != 0) ||
-		     (scsidev->lun != 0)))
-		return NULL;
+	struct ata_device *dev = __ata_scsi_find_dev(ap, scsidev);
 
-	if (unlikely(!ata_dev_enabled(dev)))
+	if (unlikely(!dev || !ata_dev_enabled(dev)))
 		return NULL;
 
 	if (!atapi_enabled || (ap->flags & ATA_FLAG_NO_ATAPI)) {
-- 
1.3.2

[PATCH 01/12] libata-hp-prep: add flags and eh_info/context fields for hotplug

[Tejun Heo]

Add hotplug related flags and eh_info/context fields.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 include/linux/libata.h |   19 ++++++++++++++++++-
 1 files changed, 18 insertions(+), 1 deletions(-)

abdda7331d469fa965167365f011d05e226008fb
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 2eb5828..d4a668c 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -131,6 +131,9 @@ enum {
 
 	ATA_DFLAG_PIO		= (1 << 8), /* device currently in PIO mode */
 
+	ATA_DFLAG_DETACH	= (1 << 16),
+	ATA_DFLAG_DETACHED	= (1 << 17),
+
 	ATA_DEV_UNKNOWN		= 0,	/* unknown device */
 	ATA_DEV_ATA		= 1,	/* ATA device */
 	ATA_DEV_ATA_UNSUP	= 2,	/* ATA device (unsupported) */
@@ -152,6 +155,9 @@ enum {
 	ATA_FLAG_PIO_POLLING	= (1 << 9), /* use polling PIO if LLD
 					     * doesn't handle PIO interrupts */
 	ATA_FLAG_NCQ		= (1 << 10), /* host supports NCQ */
+	ATA_FLAG_HRST_TO_RESUME	= (1 << 11), /* hardreset to resume phy */
+	ATA_FLAG_SKIP_D2H_BSY	= (1 << 12), /* can't wait for the first D2H
+					      * Register FIS clearing BSY */
 
 	ATA_FLAG_DEBUGMSG	= (1 << 13),
 	ATA_FLAG_FLUSH_PORT_TASK = (1 << 14), /* flush port task */
@@ -160,6 +166,9 @@ enum {
 	ATA_FLAG_EH_IN_PROGRESS	= (1 << 16), /* EH in progress */
 	ATA_FLAG_FROZEN		= (1 << 17), /* port is frozen */
 	ATA_FLAG_RECOVERED	= (1 << 18), /* recovery action performed */
+	ATA_FLAG_LOADING	= (1 << 19), /* boot/loading probe */
+	ATA_FLAG_UNLOADING	= (1 << 20), /* module is unloading */
+	ATA_FLAG_SCSI_HOTPLUG	= (1 << 21), /* SCSI hotplug scheduled */
 
 	ATA_FLAG_DISABLED	= (1 << 22), /* port is disabled, ignore it */
 	ATA_FLAG_SUSPENDED	= (1 << 23), /* port is suspended (power) */
@@ -241,7 +250,9 @@ enum {
 	ATA_EH_RESET_MASK	= ATA_EH_SOFTRESET | ATA_EH_HARDRESET,
 
 	/* ata_eh_info->flags */
-	ATA_EHI_DID_RESET	= (1 << 0), /* already reset this port */
+	ATA_EHI_HOTPLUGGED	= (1 << 0),  /* could have been hotplugged */
+
+	ATA_EHI_DID_RESET	= (1 << 16), /* already reset this port */
 
 	/* max repeat if error condition is still set after ->error_handler */
 	ATA_EH_MAX_REPEAT	= 5,
@@ -434,6 +445,10 @@ struct ata_eh_info {
 	unsigned int		err_mask;	/* port-wide err_mask */
 	unsigned int		action;		/* ATA_EH_* action mask */
 	unsigned int		flags;		/* ATA_EHI_* flags */
+
+	unsigned long		hotplug_timestamp;
+	unsigned int		probe_mask;
+
 	char			desc[ATA_EH_DESC_LEN];
 	int			desc_len;
 };
@@ -441,6 +456,8 @@ struct ata_eh_info {
 struct ata_eh_context {
 	struct ata_eh_info	i;
 	int			tries[ATA_MAX_DEVICES];
+	unsigned int		classes[ATA_MAX_DEVICES];
+	unsigned int		did_probe_mask;
 };
 
 struct ata_port {
-- 
1.3.2

[PATCH 03/12] libata-hp-prep: make some ata_device fields persistent

[Tejun Heo]

Lifetimes of some fields span over device plugging/unplugging.  This
patch moves such persistent fields to the top of ata_device and
separate them with ATA_DEVICE_CLEAR_OFFSET.  Fields above the offset
are initialized once during host initializatino while all other fields
are cleared before hotplugging.  Currently ->ap, devno and part of
flags are persistent.

Note that flags is partially cleared while holding host_set lock.
This is to synchronize with later warm plug implementation which will
record hotplug request in dev->flags.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-core.c |   14 ++++++++++++--
 include/linux/libata.h     |   11 +++++++++--
 2 files changed, 21 insertions(+), 4 deletions(-)

72fa4b742b327bd1b07985d79a61c61dbd9fd4e6
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 8fda822..a07ab77 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -5153,9 +5153,18 @@ static void ata_host_remove(struct ata_p
 void ata_dev_init(struct ata_device *dev)
 {
 	struct ata_port *ap = dev->ap;
+	unsigned long flags;
+
+	/* High bits of dev->flags are used to record warm plug
+	 * requests which occur asynchronously.  Synchronize using
+	 * host_set lock.
+	 */
+	spin_lock_irqsave(&ap->host_set->lock, flags);
+	dev->flags &= ~ATA_DFLAG_INIT_MASK;
+	spin_unlock_irqrestore(&ap->host_set->lock, flags);
 
-	memset((void *)dev, 0, sizeof(*dev));
-	dev->devno = dev - ap->device;
+	memset((void *)dev + ATA_DEVICE_CLEAR_OFFSET, 0,
+	       sizeof(*dev) - ATA_DEVICE_CLEAR_OFFSET);
 	dev->pio_mask = UINT_MAX;
 	dev->mwdma_mask = UINT_MAX;
 	dev->udma_mask = UINT_MAX;
@@ -5218,6 +5227,7 @@ static void ata_host_init(struct ata_por
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
 		struct ata_device *dev = &ap->device[i];
 		dev->ap = ap;
+		dev->devno = i;
 		ata_dev_init(dev);
 	}
 
diff --git a/include/linux/libata.h b/include/linux/libata.h
index d4a668c..aa14eda 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -130,6 +130,7 @@ enum {
 	ATA_DFLAG_CFG_MASK	= (1 << 8) - 1,
 
 	ATA_DFLAG_PIO		= (1 << 8), /* device currently in PIO mode */
+	ATA_DFLAG_INIT_MASK	= (1 << 16) - 1,
 
 	ATA_DFLAG_DETACH	= (1 << 16),
 	ATA_DFLAG_DETACHED	= (1 << 17),
@@ -410,10 +411,11 @@ struct ata_ering {
 
 struct ata_device {
 	struct ata_port		*ap;
-	u64			n_sectors;	/* size of device, if ATA */
+	unsigned int		devno;		/* 0 or 1 */
 	unsigned long		flags;		/* ATA_DFLAG_xxx */
+	/* n_sector is used as CLEAR_OFFSET, read comment above CLEAR_OFFSET */
+	u64			n_sectors;	/* size of device, if ATA */
 	unsigned int		class;		/* ATA_DEV_xxx */
-	unsigned int		devno;		/* 0 or 1 */
 	u16			id[ATA_ID_WORDS]; /* IDENTIFY xxx DEVICE data */
 	u8			pio_mode;
 	u8			dma_mode;
@@ -439,6 +441,11 @@ struct ata_device {
 	struct ata_ering	ering;
 };
 
+/* Offset into struct ata_device.  Fields above it are maintained
+ * acress device init.  Fields below are zeroed.
+ */
+#define ATA_DEVICE_CLEAR_OFFSET		offsetof(struct ata_device, n_sectors)
+
 struct ata_eh_info {
 	struct ata_device	*dev;		/* offending device */
 	u32			serror;		/* SError from LLDD */
-- 
1.3.2

[PATCH 06/12] libata-hp-prep: implement ap->hw_sata_spd_limit

[Tejun Heo]

Add ap->hw_sata_spd_limit and initialize it once during the boot
initialization (or driver load initialization).  ap->sata_spd_limit is
reset to ap->hw_sata_spd_limit on hotplug.  This prevents spd limits
introduced by earlier devices from affecting new devices.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-core.c |   21 ++++++++++++---------
 include/linux/libata.h     |    1 +
 2 files changed, 13 insertions(+), 9 deletions(-)

5a04bf4befa8bffa012eedc3a0903c158b9131a9
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index a07ab77..b1a02fd 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2466,17 +2466,9 @@ static int sata_phy_resume(struct ata_po
  */
 void ata_std_probeinit(struct ata_port *ap)
 {
-	u32 scontrol;
-
 	/* resume link */
 	sata_phy_resume(ap);
 
-	/* init sata_spd_limit to the current value */
-	if (sata_scr_read(ap, SCR_CONTROL, &scontrol) == 0) {
-		int spd = (scontrol >> 4) & 0xf;
-		ap->sata_spd_limit &= (1 << spd) - 1;
-	}
-
 	/* wait for device */
 	if (ata_port_online(ap))
 		ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
@@ -5155,6 +5147,9 @@ void ata_dev_init(struct ata_device *dev
 	struct ata_port *ap = dev->ap;
 	unsigned long flags;
 
+	/* SATA spd limit is bound to the first device */
+	ap->sata_spd_limit = ap->hw_sata_spd_limit;
+
 	/* High bits of dev->flags are used to record warm plug
 	 * requests which occur asynchronously.  Synchronize using
 	 * host_set lock.
@@ -5210,7 +5205,7 @@ static void ata_host_init(struct ata_por
 	ap->udma_mask = ent->udma_mask;
 	ap->flags |= ent->host_flags;
 	ap->ops = ent->port_ops;
-	ap->sata_spd_limit = UINT_MAX;
+	ap->hw_sata_spd_limit = UINT_MAX;
 	ap->active_tag = ATA_TAG_POISON;
 	ap->last_ctl = 0xFF;
 	ap->msg_enable = ATA_MSG_DRV;
@@ -5375,10 +5370,18 @@ int ata_device_add(const struct ata_prob
 	DPRINTK("probe begin\n");
 	for (i = 0; i < count; i++) {
 		struct ata_port *ap;
+		u32 scontrol;
 		int rc;
 
 		ap = host_set->ports[i];
 
+		/* init sata_spd_limit to the current value */
+		if (sata_scr_read(ap, SCR_CONTROL, &scontrol) == 0) {
+			int spd = (scontrol >> 4) & 0xf;
+			ap->hw_sata_spd_limit &= (1 << spd) - 1;
+		}
+		ap->sata_spd_limit = ap->hw_sata_spd_limit;
+
 		DPRINTK("ata%u: bus probe begin\n", ap->id);
 		rc = ata_bus_probe(ap);
 		DPRINTK("ata%u: bus probe end\n", ap->id);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index aa14eda..10dc235 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -489,6 +489,7 @@ struct ata_port {
 	unsigned int		mwdma_mask;
 	unsigned int		udma_mask;
 	unsigned int		cbl;	/* cable type; ATA_CBL_xxx */
+	unsigned int		hw_sata_spd_limit;
 	unsigned int		sata_spd_limit;	/* SATA PHY speed limit */
 
 	/* record runtime error info, protected by host_set lock */
-- 
1.3.2

[PATCH 05/12] libata-hp-prep: use __ata_scsi_find_dev()

[Tejun Heo]

Convert direct sdev -> dev lookup to __ata_scsi_find_dev().

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-scsi.c |   16 ++++++----------
 1 files changed, 6 insertions(+), 10 deletions(-)

315343637b988ac32d730a6a9f7bf5866838bcb0
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index b45b8b3..0509076 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -399,7 +399,7 @@ void ata_dump_status(unsigned id, struct
 int ata_scsi_device_resume(struct scsi_device *sdev)
 {
 	struct ata_port *ap = ata_shost_to_port(sdev->host);
-	struct ata_device *dev = &ap->device[sdev->id];
+	struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
 
 	return ata_device_resume(dev);
 }
@@ -407,7 +407,7 @@ int ata_scsi_device_resume(struct scsi_d
 int ata_scsi_device_suspend(struct scsi_device *sdev, pm_message_t state)
 {
 	struct ata_port *ap = ata_shost_to_port(sdev->host);
-	struct ata_device *dev = &ap->device[sdev->id];
+	struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
 
 	return ata_device_suspend(dev, state);
 }
@@ -713,19 +713,15 @@ static void ata_scsi_dev_config(struct s
 
 int ata_scsi_slave_config(struct scsi_device *sdev)
 {
+	struct ata_port *ap = ata_shost_to_port(sdev->host);
+	struct ata_device *dev = __ata_scsi_find_dev(ap, sdev);
+
 	ata_scsi_sdev_config(sdev);
 
 	blk_queue_max_phys_segments(sdev->request_queue, LIBATA_MAX_PRD);
 
-	if (sdev->id < ATA_MAX_DEVICES) {
-		struct ata_port *ap;
-		struct ata_device *dev;
-
-		ap = ata_shost_to_port(sdev->host);
-		dev = &ap->device[sdev->id];
-
+	if (dev)
 		ata_scsi_dev_config(sdev, dev);
-	}
 
 	return 0;	/* scsi layer doesn't check return value, sigh */
 }
-- 
1.3.2

[PATCH 11/12] libata-hp-prep: add prereset() method and implement ata_std_prereset()

[Tejun Heo]

With hotplug, every reset might be a probing reset and thus something
similar to probe_init() is needed.  prereset() method is called before
a series of resets to a port and is the counterpart of postreset().
prereset() can tell EH to use different type of reset or skip reset by
modifying ehc->i.action.

This patch also implements ata_std_prereset().  Most controllers
should be able to use this function directly or with some wrapping.
After hotplug, different controllers need different actions to resume
the PHY and detect the newly attached device.  Controllers can be
categorized as follows.

* Controllers which can wait for the first D2H FIS after hotplug.
  Note that if the waiting is implemented by polling TF status, there
  needs to be a way to set BSY on PHY status change.  It can be
  implemented by hardware or with the help of the driver.

* Controllers which can wait for the first D2H FIS after sending
  COMRESET.  These controllers need to issue COMRESET to wait for the
  first FIS.  Note that the received D2H FIS could be the first D2H
  FIS after POR (power-on-reset) or D2H FIS in response to the
  COMRESET.  Some controllers use COMRESET as TF status
  synchronization point and clear TF automatically (sata_sil).

* Controllers which cannot wait for the first D2H FIS reliably.
  Blindly issuing SRST to spinning-up device often results in command
  issue failure or timeout, causing extended delay.  For these
  controllers, ata_std_prereset() explicitly waits ATA_SPINUP_WAIT
  (currently 8s) to give newly attached device time to spin up, then
  issues reset.  Note that failing to getting ready in ATA_SPINUP_WAIT
  is not critical.  libata will retry.  So, the timeout needs to be
  long enough to spin up most devices.

LLDDs can tell ata_std_prereset() which of above action is needed with
ATA_FLAG_HRST_TO_RESUME and ATA_FLAG_SKIP_D2H_BSY flags.  These flags
are PHY-specific property and will be moved to ata_link later.

While at it, this patch unifies function typedef's such that they all
have named arguments.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/ahci.c         |    3 +-
 drivers/scsi/libata-bmdma.c |   11 ++++--
 drivers/scsi/libata-core.c  |   85 +++++++++++++++++++++++++++++++++++++++++++
 drivers/scsi/libata-eh.c    |   60 ++++++++++++++++++++++++++----
 drivers/scsi/sata_sil24.c   |    3 +-
 include/linux/libata.h      |   24 +++++++++---
 6 files changed, 165 insertions(+), 21 deletions(-)

f5914a461eb9703773226a0813f6ffcae10c0861
diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index 45fd71d..8493b02 100644
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -1026,7 +1026,8 @@ static void ahci_error_handler(struct at
 	}
 
 	/* perform recovery */
-	ata_do_eh(ap, ahci_softreset, ahci_hardreset, ahci_postreset);
+	ata_do_eh(ap, ata_std_prereset, ahci_softreset, ahci_hardreset,
+		  ahci_postreset);
 }
 
 static void ahci_post_internal_cmd(struct ata_queued_cmd *qc)
diff --git a/drivers/scsi/libata-bmdma.c b/drivers/scsi/libata-bmdma.c
index 6d30d2c..4bc0537 100644
--- a/drivers/scsi/libata-bmdma.c
+++ b/drivers/scsi/libata-bmdma.c
@@ -695,6 +695,7 @@ void ata_bmdma_thaw(struct ata_port *ap)
 /**
  *	ata_bmdma_drive_eh - Perform EH with given methods for BMDMA controller
  *	@ap: port to handle error for
+ *	@prereset: prereset method (can be NULL)
  *	@softreset: softreset method (can be NULL)
  *	@hardreset: hardreset method (can be NULL)
  *	@postreset: postreset method (can be NULL)
@@ -710,8 +711,9 @@ void ata_bmdma_thaw(struct ata_port *ap)
  *	LOCKING:
  *	Kernel thread context (may sleep)
  */
-void ata_bmdma_drive_eh(struct ata_port *ap, ata_reset_fn_t softreset,
-			ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
+void ata_bmdma_drive_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
+			ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
+			ata_postreset_fn_t postreset)
 {
 	struct ata_host_set *host_set = ap->host_set;
 	struct ata_eh_context *ehc = &ap->eh_context;
@@ -759,7 +761,7 @@ void ata_bmdma_drive_eh(struct ata_port 
 		ata_eh_thaw_port(ap);
 
 	/* PIO and DMA engines have been stopped, perform recovery */
-	ata_do_eh(ap, softreset, hardreset, postreset);
+	ata_do_eh(ap, prereset, softreset, hardreset, postreset);
 }
 
 /**
@@ -779,7 +781,8 @@ void ata_bmdma_error_handler(struct ata_
 	if (sata_scr_valid(ap))
 		hardreset = sata_std_hardreset;
 
-	ata_bmdma_drive_eh(ap, ata_std_softreset, hardreset, ata_std_postreset);
+	ata_bmdma_drive_eh(ap, ata_std_prereset, ata_std_softreset, hardreset,
+			   ata_std_postreset);
 }
 
 /**
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 4823ece..2531a70 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2525,6 +2525,90 @@ int sata_phy_resume(struct ata_port *ap,
 	return sata_phy_debounce(ap, params);
 }
 
+static void ata_wait_spinup(struct ata_port *ap)
+{
+	struct ata_eh_context *ehc = &ap->eh_context;
+	unsigned long end, secs;
+	int rc;
+
+	/* first, debounce phy if SATA */
+	if (ap->cbl == ATA_CBL_SATA) {
+		rc = sata_phy_debounce(ap, sata_deb_timing_eh);
+
+		/* if debounced successfully and offline, no need to wait */
+		if ((rc == 0 || rc == -EOPNOTSUPP) && ata_port_offline(ap))
+			return;
+	}
+
+	/* okay, let's give the drive time to spin up */
+	end = ehc->i.hotplug_timestamp + ATA_SPINUP_WAIT * HZ / 1000;
+	secs = ((end - jiffies) + HZ - 1) / HZ;
+
+	if (time_after(jiffies, end))
+		return;
+
+	if (secs > 5)
+		ata_port_printk(ap, KERN_INFO, "waiting for device to spin up "
+				"(%lu secs)\n", secs);
+
+	schedule_timeout_uninterruptible(end - jiffies);
+}
+
+/**
+ *	ata_std_prereset - prepare for reset
+ *	@ap: ATA port to be reset
+ *
+ *	@ap is about to be reset.  Initialize it.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep)
+ *
+ *	RETURNS:
+ *	0 on success, -errno otherwise.
+ */
+int ata_std_prereset(struct ata_port *ap)
+{
+	struct ata_eh_context *ehc = &ap->eh_context;
+	const unsigned long *timing;
+	int rc;
+
+	/* hotplug? */
+	if (ehc->i.flags & ATA_EHI_HOTPLUGGED) {
+		if (ap->flags & ATA_FLAG_HRST_TO_RESUME)
+			ehc->i.action |= ATA_EH_HARDRESET;
+		if (ap->flags & ATA_FLAG_SKIP_D2H_BSY)
+			ata_wait_spinup(ap);
+	}
+
+	/* if we're about to do hardreset, nothing more to do */
+	if (ehc->i.action & ATA_EH_HARDRESET)
+		return 0;
+
+	/* if SATA, resume phy */
+	if (ap->cbl == ATA_CBL_SATA) {
+		if (ap->flags & ATA_FLAG_LOADING)
+			timing = sata_deb_timing_boot;
+		else
+			timing = sata_deb_timing_eh;
+
+		rc = sata_phy_resume(ap, timing);
+		if (rc && rc != -EOPNOTSUPP) {
+			/* phy resume failed */
+			ata_port_printk(ap, KERN_WARNING, "failed to resume "
+					"link for reset (errno=%d)\n", rc);
+			return rc;
+		}
+	}
+
+	/* Wait for !BSY if the controller can wait for the first D2H
+	 * Reg FIS and we don't know that no device is attached.
+	 */
+	if (!(ap->flags & ATA_FLAG_SKIP_D2H_BSY) && !ata_port_offline(ap))
+		ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
+
+	return 0;
+}
+
 /**
  *	ata_std_probeinit - initialize probing
  *	@ap: port to be probed
@@ -5840,6 +5924,7 @@ EXPORT_SYMBOL_GPL(sata_phy_reset);
 EXPORT_SYMBOL_GPL(__sata_phy_reset);
 EXPORT_SYMBOL_GPL(ata_bus_reset);
 EXPORT_SYMBOL_GPL(ata_std_probeinit);
+EXPORT_SYMBOL_GPL(ata_std_prereset);
 EXPORT_SYMBOL_GPL(ata_std_softreset);
 EXPORT_SYMBOL_GPL(sata_std_hardreset);
 EXPORT_SYMBOL_GPL(ata_std_postreset);
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 9173d8f..0e66f14 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -1318,20 +1318,58 @@ static void ata_eh_report(struct ata_por
 	}
 }
 
-static int ata_eh_reset(struct ata_port *ap, ata_reset_fn_t softreset,
+static int ata_eh_reset(struct ata_port *ap,
+			ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
 			ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 {
 	struct ata_eh_context *ehc = &ap->eh_context;
 	unsigned int classes[ATA_MAX_DEVICES];
 	int tries = ATA_EH_RESET_TRIES;
+	unsigned int action;
 	ata_reset_fn_t reset;
 	int i, rc;
 
+	/* Determine which reset to use and record in ehc->i.action.
+	 * prereset() may examine and modify it.
+	 */
+	action = ehc->i.action;
+	ehc->i.action &= ~ATA_EH_RESET_MASK;
 	if (softreset && (!hardreset || (!sata_set_spd_needed(ap) &&
-					 !(ehc->i.action & ATA_EH_HARDRESET))))
-		reset = softreset;
+					 !(action & ATA_EH_HARDRESET))))
+		ehc->i.action |= ATA_EH_SOFTRESET;
 	else
+		ehc->i.action |= ATA_EH_HARDRESET;
+
+	if (prereset) {
+		rc = prereset(ap);
+		if (rc) {
+			ata_port_printk(ap, KERN_ERR,
+					"prereset failed (errno=%d)\n", rc);
+			return rc;
+		}
+	}
+
+	/* prereset() might have modified ehc->i.action */
+	if (ehc->i.action & ATA_EH_HARDRESET)
 		reset = hardreset;
+	else if (ehc->i.action & ATA_EH_SOFTRESET)
+		reset = softreset;
+	else {
+		/* prereset told us not to reset, bang classes and return */
+		for (i = 0; i < ATA_MAX_DEVICES; i++)
+			classes[i] = ATA_DEV_NONE;
+		return 0;
+	}
+
+	/* did prereset() screw up?  if so, fix up to avoid oopsing */
+	if (!reset) {
+		ata_port_printk(ap, KERN_ERR, "BUG: prereset() requested "
+				"invalid reset type\n");
+		if (softreset)
+			reset = softreset;
+		else
+			reset = hardreset;
+	}
 
  retry:
 	ata_port_printk(ap, KERN_INFO, "%s resetting port\n",
@@ -1424,6 +1462,7 @@ static int ata_port_nr_enabled(struct at
 /**
  *	ata_eh_recover - recover host port after error
  *	@ap: host port to recover
+ *	@prereset: prereset method (can be NULL)
  *	@softreset: softreset method (can be NULL)
  *	@hardreset: hardreset method (can be NULL)
  *	@postreset: postreset method (can be NULL)
@@ -1440,8 +1479,8 @@ static int ata_port_nr_enabled(struct at
  *	RETURNS:
  *	0 on success, -errno on failure.
  */
-static int ata_eh_recover(struct ata_port *ap, ata_reset_fn_t softreset,
-			  ata_reset_fn_t hardreset,
+static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
+			  ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
 			  ata_postreset_fn_t postreset)
 {
 	struct ata_eh_context *ehc = &ap->eh_context;
@@ -1469,7 +1508,8 @@ static int ata_eh_recover(struct ata_por
 	if (ehc->i.action & ATA_EH_RESET_MASK) {
 		ata_eh_freeze_port(ap);
 
-		rc = ata_eh_reset(ap, softreset, hardreset, postreset);
+		rc = ata_eh_reset(ap, prereset, softreset, hardreset,
+				  postreset);
 		if (rc) {
 			ata_port_printk(ap, KERN_ERR,
 					"reset failed, giving up\n");
@@ -1586,6 +1626,7 @@ static void ata_eh_finish(struct ata_por
 /**
  *	ata_do_eh - do standard error handling
  *	@ap: host port to handle error for
+ *	@prereset: prereset method (can be NULL)
  *	@softreset: softreset method (can be NULL)
  *	@hardreset: hardreset method (can be NULL)
  *	@postreset: postreset method (can be NULL)
@@ -1595,11 +1636,12 @@ static void ata_eh_finish(struct ata_por
  *	LOCKING:
  *	Kernel thread context (may sleep).
  */
-void ata_do_eh(struct ata_port *ap, ata_reset_fn_t softreset,
-	       ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
+void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
+	       ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
+	       ata_postreset_fn_t postreset)
 {
 	ata_eh_autopsy(ap);
 	ata_eh_report(ap);
-	ata_eh_recover(ap, softreset, hardreset, postreset);
+	ata_eh_recover(ap, prereset, softreset, hardreset, postreset);
 	ata_eh_finish(ap);
 }
diff --git a/drivers/scsi/sata_sil24.c b/drivers/scsi/sata_sil24.c
index 4c76f05..26d7c54 100644
--- a/drivers/scsi/sata_sil24.c
+++ b/drivers/scsi/sata_sil24.c
@@ -912,7 +912,8 @@ static void sil24_error_handler(struct a
 	}
 
 	/* perform recovery */
-	ata_do_eh(ap, sil24_softreset, sil24_hardreset, ata_std_postreset);
+	ata_do_eh(ap, ata_std_prereset, sil24_softreset, sil24_hardreset,
+		  ata_std_postreset);
 }
 
 static void sil24_post_internal_cmd(struct ata_queued_cmd *qc)
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 1c167f7..fe5f539 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -262,6 +262,15 @@ enum {
 	ATA_PROBE_MAX_TRIES	= 3,
 	ATA_EH_RESET_TRIES	= 3,
 	ATA_EH_DEV_TRIES	= 3,
+
+	/* Drive spinup time (time from power-on to the first D2H FIS)
+	 * in msecs - 8s currently.  Failing to get ready in this time
+	 * isn't critical.  It will result in reset failure for
+	 * controllers which can't wait for the first D2H FIS.  libata
+	 * will retry, so it just has to be long enough to spin up
+	 * most devices.
+	 */
+	ATA_SPINUP_WAIT		= 8000,
 };
 
 enum hsm_task_states {
@@ -294,9 +303,10 @@ struct ata_queued_cmd;
 
 /* typedefs */
 typedef void (*ata_qc_cb_t) (struct ata_queued_cmd *qc);
-typedef void (*ata_probeinit_fn_t)(struct ata_port *);
-typedef int (*ata_reset_fn_t)(struct ata_port *, unsigned int *);
-typedef void (*ata_postreset_fn_t)(struct ata_port *ap, unsigned int *);
+typedef void (*ata_probeinit_fn_t)(struct ata_port *ap);
+typedef int (*ata_prereset_fn_t)(struct ata_port *ap);
+typedef int (*ata_reset_fn_t)(struct ata_port *ap, unsigned int *classes);
+typedef void (*ata_postreset_fn_t)(struct ata_port *ap, unsigned int *classes);
 
 struct ata_ioports {
 	unsigned long		cmd_addr;
@@ -623,6 +633,7 @@ extern int ata_drive_probe_reset(struct 
 			ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
 			ata_postreset_fn_t postreset, unsigned int *classes);
 extern void ata_std_probeinit(struct ata_port *ap);
+extern int ata_std_prereset(struct ata_port *ap);
 extern int ata_std_softreset(struct ata_port *ap, unsigned int *classes);
 extern int sata_std_hardreset(struct ata_port *ap, unsigned int *class);
 extern void ata_std_postreset(struct ata_port *ap, unsigned int *classes);
@@ -706,7 +717,7 @@ extern u8   ata_bmdma_status(struct ata_
 extern void ata_bmdma_irq_clear(struct ata_port *ap);
 extern void ata_bmdma_freeze(struct ata_port *ap);
 extern void ata_bmdma_thaw(struct ata_port *ap);
-extern void ata_bmdma_drive_eh(struct ata_port *ap,
+extern void ata_bmdma_drive_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
 			       ata_reset_fn_t softreset,
 			       ata_reset_fn_t hardreset,
 			       ata_postreset_fn_t postreset);
@@ -784,8 +795,9 @@ extern void ata_eh_thaw_port(struct ata_
 extern void ata_eh_qc_complete(struct ata_queued_cmd *qc);
 extern void ata_eh_qc_retry(struct ata_queued_cmd *qc);
 
-extern void ata_do_eh(struct ata_port *ap, ata_reset_fn_t softreset,
-		      ata_reset_fn_t hardreset, ata_postreset_fn_t postreset);
+extern void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
+		      ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
+		      ata_postreset_fn_t postreset);
 
 /*
  * printk helpers
-- 
1.3.2

[PATCH 12/12] libata-hp-prep: implement followup softreset handling

[Tejun Heo]

In some cases, hardreset must be followed by SRST.

* some controllers can't classify with hardreset
* some controllers can't wait for !BSY after hardreset (LLDD should
  explicitly request followup softreset by returning -EAGAIN)
* (later) PM needs SRST w/ PMP==15 to operate after hardreset

To handle above cases, this patch implements follow-up softreset.
After a hardreset, ata_eh_reset() checks whether any of above
conditions are met and do a follow-up softreset if necessary.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-eh.c |   58 +++++++++++++++++++++++++++++++++++++++++-----
 1 files changed, 52 insertions(+), 6 deletions(-)

664faf09a05d74085c0b31e2c621d7647322325b
diff --git a/drivers/scsi/libata-eh.c b/drivers/scsi/libata-eh.c
index 0e66f14..8ecb842 100644
--- a/drivers/scsi/libata-eh.c
+++ b/drivers/scsi/libata-eh.c
@@ -1318,16 +1318,28 @@ static void ata_eh_report(struct ata_por
 	}
 }
 
-static int ata_eh_reset(struct ata_port *ap,
+static int ata_eh_followup_srst_needed(int rc, int classify,
+				       const unsigned int *classes)
+{
+	if (rc == -EAGAIN)
+		return 1;
+	if (rc != 0)
+		return 0;
+	if (classify && classes[0] == ATA_DEV_UNKNOWN)
+		return 1;
+	return 0;
+}
+
+static int ata_eh_reset(struct ata_port *ap, int classify,
 			ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
 			ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 {
 	struct ata_eh_context *ehc = &ap->eh_context;
-	unsigned int classes[ATA_MAX_DEVICES];
+	unsigned int *classes = ehc->classes;
 	int tries = ATA_EH_RESET_TRIES;
 	unsigned int action;
 	ata_reset_fn_t reset;
-	int i, rc;
+	int i, did_followup_srst, rc;
 
 	/* Determine which reset to use and record in ehc->i.action.
 	 * prereset() may examine and modify it.
@@ -1381,10 +1393,44 @@ static int ata_eh_reset(struct ata_port 
 
 	rc = ata_do_reset(ap, reset, classes);
 
+	did_followup_srst = 0;
+	if (reset == hardreset &&
+	    ata_eh_followup_srst_needed(rc, classify, classes)) {
+		/* okay, let's do follow-up softreset */
+		did_followup_srst = 1;
+		reset = softreset;
+
+		if (!reset) {
+			ata_port_printk(ap, KERN_ERR,
+					"follow-up softreset required "
+					"but no softreset avaliable\n");
+			return -EINVAL;
+		}
+
+		ata_eh_about_to_do(ap, ATA_EH_RESET_MASK);
+		rc = ata_do_reset(ap, reset, classes);
+
+		if (rc == 0 && classify &&
+		    classes[0] == ATA_DEV_UNKNOWN) {
+			ata_port_printk(ap, KERN_ERR,
+					"classification failed\n");
+			return -EINVAL;
+		}
+	}
+
 	if (rc && --tries) {
+		const char *type;
+
+		if (reset == softreset) {
+			if (did_followup_srst)
+				type = "follow-up soft";
+			else
+				type = "soft";
+		} else
+			type = "hard";
+
 		ata_port_printk(ap, KERN_WARNING,
-				"%sreset failed, retrying in 5 secs\n",
-				reset == softreset ? "soft" : "hard");
+				"%sreset failed, retrying in 5 secs\n", type);
 		ssleep(5);
 
 		if (reset == hardreset)
@@ -1508,7 +1554,7 @@ static int ata_eh_recover(struct ata_por
 	if (ehc->i.action & ATA_EH_RESET_MASK) {
 		ata_eh_freeze_port(ap);
 
-		rc = ata_eh_reset(ap, prereset, softreset, hardreset,
+		rc = ata_eh_reset(ap, 0, prereset, softreset, hardreset,
 				  postreset);
 		if (rc) {
 			ata_port_printk(ap, KERN_ERR,
-- 
1.3.2

[PATCH 08/12] libata-hp-prep: add ata_aux_wq

[Tejun Heo]

It's best to run ATA hotplug from EH but attaching SCSI devices needs
working EH.  ata_aux_wq is used to give SCSI hotplug operations a
separate context.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-core.c |    9 +++++++++
 drivers/scsi/libata.h      |    1 +
 2 files changed, 10 insertions(+), 0 deletions(-)

453b07accb47c5b54aa2f156ebffac63c543027b
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index b1a02fd..04921cf 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -69,6 +69,8 @@ static void ata_dev_xfermask(struct ata_
 static unsigned int ata_unique_id = 1;
 static struct workqueue_struct *ata_wq;
 
+struct workqueue_struct *ata_aux_wq;
+
 int atapi_enabled = 1;
 module_param(atapi_enabled, int, 0444);
 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
@@ -5623,6 +5625,12 @@ static int __init ata_init(void)
 	if (!ata_wq)
 		return -ENOMEM;
 
+	ata_aux_wq = create_singlethread_workqueue("ata_aux");
+	if (!ata_aux_wq) {
+		destroy_workqueue(ata_wq);
+		return -ENOMEM;
+	}
+
 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
 	return 0;
 }
@@ -5630,6 +5638,7 @@ static int __init ata_init(void)
 static void __exit ata_exit(void)
 {
 	destroy_workqueue(ata_wq);
+	destroy_workqueue(ata_aux_wq);
 }
 
 module_init(ata_init);
diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index c2b1c91..4458fd9 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -39,6 +39,7 @@ struct ata_scsi_args {
 };
 
 /* libata-core.c */
+extern struct workqueue_struct *ata_aux_wq;
 extern int atapi_enabled;
 extern int atapi_dmadir;
 extern int libata_fua;
-- 
1.3.2

[PATCH 09/12] libata-hp-prep: make probing related functions global

[Tejun Heo]

Hotplug will be implemented in libata-eh.c.  Make ata_dev_read_id()
and ata_dev_configure() global.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-core.c |    6 +++---
 drivers/scsi/libata.h      |    3 +++
 2 files changed, 6 insertions(+), 3 deletions(-)

a9beec95352ff675f27d74c3cb97dc258d022497
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 04921cf..a9f79b4 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -1167,8 +1167,8 @@ unsigned int ata_pio_need_iordy(const st
  *	RETURNS:
  *	0 on success, -errno otherwise.
  */
-static int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
-			   int post_reset, u16 *id)
+int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
+		    int post_reset, u16 *id)
 {
 	struct ata_port *ap = dev->ap;
 	unsigned int class = *p_class;
@@ -1292,7 +1292,7 @@ static void ata_dev_config_ncq(struct at
  *	RETURNS:
  *	0 on success, -errno otherwise
  */
-static int ata_dev_configure(struct ata_device *dev, int print_info)
+int ata_dev_configure(struct ata_device *dev, int print_info)
 {
 	struct ata_port *ap = dev->ap;
 	const u16 *id = dev->id;
diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index 4458fd9..2d704be 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -50,6 +50,9 @@ extern void ata_port_flush_task(struct a
 extern unsigned ata_exec_internal(struct ata_device *dev,
 				  struct ata_taskfile *tf, const u8 *cdb,
 				  int dma_dir, void *buf, unsigned int buflen);
+extern int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
+			   int post_reset, u16 *id);
+extern int ata_dev_configure(struct ata_device *dev, int print_info);
 extern int sata_down_spd_limit(struct ata_port *ap);
 extern int sata_set_spd_needed(struct ata_port *ap);
 extern int ata_down_xfermask_limit(struct ata_device *dev, int force_pio0);
-- 
1.3.2

[PATCH 10/12] libata-hp-prep: implement sata_phy_debounce()

[Tejun Heo]

With hotplug, PHY always needs to be debounced before a reset as any
reset might find new devices.  Extract PHY waiting code from
sata_phy_resume() and extend it to include SStatus debouncing.  Note
that sata_phy_debounce() is superset of what used to be done inside
sata_phy_resume().

Three default debounce timing parameters are defined to be used by
hot/boot plug.  As resume failure during probing will be properly
handled as errors, timeout doesn't have to be long as before.
probeinit() uses the same timeout to retain the original behavior.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-core.c |  107 ++++++++++++++++++++++++++++++++++++++------
 include/linux/libata.h     |    6 ++
 2 files changed, 99 insertions(+), 14 deletions(-)

d7bb4cc7575929a60b0a718daa1bce87bea9a9cc
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index a9f79b4..4823ece 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -61,6 +61,11 @@ #include <asm/byteorder.h>
 
 #include "libata.h"
 
+/* debounce timing parameters in msecs { interval, duration, timeout } */
+const unsigned long sata_deb_timing_boot[]		= {   5,  100, 2000 };
+const unsigned long sata_deb_timing_eh[]		= {  25,  500, 2000 };
+const unsigned long sata_deb_timing_before_fsrst[]	= { 100, 2000, 5000 };
+
 static unsigned int ata_dev_init_params(struct ata_device *dev,
 					u16 heads, u16 sectors);
 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
@@ -2427,10 +2432,81 @@ err_out:
 	DPRINTK("EXIT\n");
 }
 
-static int sata_phy_resume(struct ata_port *ap)
+/**
+ *	sata_phy_debounce - debounce SATA phy status
+ *	@ap: ATA port to debounce SATA phy status for
+ *	@params: timing parameters { interval, duratinon, timeout } in msec
+ *
+ *	Make sure SStatus of @ap reaches stable state, determined by
+ *	holding the same value where DET is not 1 for @duration polled
+ *	every @interval, before @timeout.  Timeout constraints the
+ *	beginning of the stable state.  Because, after hot unplugging,
+ *	DET gets stuck at 1 on some controllers, this functions waits
+ *	until timeout then returns 0 if DET is stable at 1.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep)
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+int sata_phy_debounce(struct ata_port *ap, const unsigned long *params)
 {
-	unsigned long timeout = jiffies + (HZ * 5);
-	u32 scontrol, sstatus;
+	unsigned long interval_msec = params[0];
+	unsigned long duration = params[1] * HZ / 1000;
+	unsigned long timeout = jiffies + params[2] * HZ / 1000;
+	unsigned long last_jiffies;
+	u32 last, cur;
+	int rc;
+
+	if ((rc = sata_scr_read(ap, SCR_STATUS, &cur)))
+		return rc;
+	cur &= 0xf;
+
+	last = cur;
+	last_jiffies = jiffies;
+
+	while (1) {
+		msleep(interval_msec);
+		if ((rc = sata_scr_read(ap, SCR_STATUS, &cur)))
+			return rc;
+		cur &= 0xf;
+
+		/* DET stable? */
+		if (cur == last) {
+			if (cur == 1 && time_before(jiffies, timeout))
+				continue;
+			if (time_after(jiffies, last_jiffies + duration))
+				return 0;
+			continue;
+		}
+
+		/* unstable, start over */
+		last = cur;
+		last_jiffies = jiffies;
+
+		/* check timeout */
+		if (time_after(jiffies, timeout))
+			return -EBUSY;
+	}
+}
+
+/**
+ *	sata_phy_resume - resume SATA phy
+ *	@ap: ATA port to resume SATA phy for
+ *	@params: timing parameters { interval, duratinon, timeout } in msec
+ *
+ *	Resume SATA phy of @ap and debounce it.
+ *
+ *	LOCKING:
+ *	Kernel thread context (may sleep)
+ *
+ *	RETURNS:
+ *	0 on success, -errno on failure.
+ */
+int sata_phy_resume(struct ata_port *ap, const unsigned long *params)
+{
+	u32 scontrol;
 	int rc;
 
 	if ((rc = sata_scr_read(ap, SCR_CONTROL, &scontrol)))
@@ -2441,16 +2517,12 @@ static int sata_phy_resume(struct ata_po
 	if ((rc = sata_scr_write(ap, SCR_CONTROL, scontrol)))
 		return rc;
 
-	/* Wait for phy to become ready, if necessary. */
-	do {
-		msleep(200);
-		if ((rc = sata_scr_read(ap, SCR_STATUS, &sstatus)))
-			return rc;
-		if ((sstatus & 0xf) != 1)
-			return 0;
-	} while (time_before(jiffies, timeout));
+	/* Some PHYs react badly if SStatus is pounded immediately
+	 * after resuming.  Delay 200ms before debouncing.
+	 */
+	msleep(200);
 
-	return -EBUSY;
+	return sata_phy_debounce(ap, params);
 }
 
 /**
@@ -2468,8 +2540,10 @@ static int sata_phy_resume(struct ata_po
  */
 void ata_std_probeinit(struct ata_port *ap)
 {
+	static const unsigned long deb_timing[] = { 5, 100, 5000 };
+
 	/* resume link */
-	sata_phy_resume(ap);
+	sata_phy_resume(ap, deb_timing);
 
 	/* wait for device */
 	if (ata_port_online(ap))
@@ -2585,7 +2659,7 @@ int sata_std_hardreset(struct ata_port *
 	msleep(1);
 
 	/* bring phy back */
-	sata_phy_resume(ap);
+	sata_phy_resume(ap, sata_deb_timing_eh);
 
 	/* TODO: phy layer with polling, timeouts, etc. */
 	if (ata_port_offline(ap)) {
@@ -5718,6 +5792,9 @@ u32 ata_wait_register(void __iomem *reg,
  * Do not depend on ABI/API stability.
  */
 
+EXPORT_SYMBOL_GPL(sata_deb_timing_boot);
+EXPORT_SYMBOL_GPL(sata_deb_timing_eh);
+EXPORT_SYMBOL_GPL(sata_deb_timing_before_fsrst);
 EXPORT_SYMBOL_GPL(ata_std_bios_param);
 EXPORT_SYMBOL_GPL(ata_std_ports);
 EXPORT_SYMBOL_GPL(ata_device_add);
@@ -5757,6 +5834,8 @@ EXPORT_SYMBOL_GPL(ata_bmdma_error_handle
 EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
 EXPORT_SYMBOL_GPL(ata_port_probe);
 EXPORT_SYMBOL_GPL(sata_set_spd);
+EXPORT_SYMBOL_GPL(sata_phy_debounce);
+EXPORT_SYMBOL_GPL(sata_phy_resume);
 EXPORT_SYMBOL_GPL(sata_phy_reset);
 EXPORT_SYMBOL_GPL(__sata_phy_reset);
 EXPORT_SYMBOL_GPL(ata_bus_reset);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index c0513c7..1c167f7 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -607,11 +607,17 @@ struct ata_timing {
 
 #define FIT(v,vmin,vmax)	max_t(short,min_t(short,v,vmax),vmin)
 
+extern const unsigned long sata_deb_timing_boot[];
+extern const unsigned long sata_deb_timing_eh[];
+extern const unsigned long sata_deb_timing_before_fsrst[];
+
 extern void ata_port_probe(struct ata_port *);
 extern void __sata_phy_reset(struct ata_port *ap);
 extern void sata_phy_reset(struct ata_port *ap);
 extern void ata_bus_reset(struct ata_port *ap);
 extern int sata_set_spd(struct ata_port *ap);
+extern int sata_phy_debounce(struct ata_port *ap, const unsigned long *param);
+extern int sata_phy_resume(struct ata_port *ap, const unsigned long *param);
 extern int ata_drive_probe_reset(struct ata_port *ap,
 			ata_probeinit_fn_t probeinit,
 			ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
-- 
1.3.2

[PATCH 07/12] libata-hp-prep: store attached SCSI device

[Tejun Heo]

Add device persistent field dev->sdev and store the attached SCSI
device.  With hotplug, libata needs to know the attached SCSI device
to offline and detach it, but scsi_device_lookup() cannot be used
because libata will reuse SCSI ID numbers - dead but not gone devices
(due to zombie opens, etc...) interfere with the lookup.

dev->sdev doesn't hold reference to the SCSI device.  It's cleared
when the SCSI device goes away.

Signed-off-by: Tejun Heo <htejun@gmail.com>

---

 drivers/scsi/libata-scsi.c |   14 ++++++++++----
 include/linux/libata.h     |    1 +
 2 files changed, 11 insertions(+), 4 deletions(-)

3edebac41bab7e146578ad9e723ee7fff71c99c0
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 0509076..da9689b 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -2743,16 +2743,22 @@ void ata_scsi_simulate(struct ata_device
 
 void ata_scsi_scan_host(struct ata_port *ap)
 {
-	struct ata_device *dev;
 	unsigned int i;
 
 	if (ap->flags & ATA_FLAG_DISABLED)
 		return;
 
 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
-		dev = &ap->device[i];
+		struct ata_device *dev = &ap->device[i];
+		struct scsi_device *sdev;
+
+		if (!ata_dev_enabled(dev) || dev->sdev)
+			continue;
 
-		if (ata_dev_enabled(dev))
-			scsi_scan_target(&ap->host->shost_gendev, 0, i, 0, 0);
+		sdev = __scsi_add_device(ap->host, 0, i, 0, NULL);
+		if (!IS_ERR(sdev)) {
+			dev->sdev = sdev;
+			scsi_device_put(sdev);
+		}
 	}
 }
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 10dc235..c0513c7 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -413,6 +413,7 @@ struct ata_device {
 	struct ata_port		*ap;
 	unsigned int		devno;		/* 0 or 1 */
 	unsigned long		flags;		/* ATA_DFLAG_xxx */
+	struct scsi_device	*sdev;		/* attached SCSI device */
 	/* n_sector is used as CLEAR_OFFSET, read comment above CLEAR_OFFSET */
 	u64			n_sectors;	/* size of device, if ATA */
 	unsigned int		class;		/* ATA_DEV_xxx */
-- 
1.3.2

Re: [PATCHSET 01/03] prep for hotplug support, take 5

[Tejun Heo]

Tejun Heo wrote:
> Hello,
> 
> This is part of patchset series described in [T].
> 
> This is the fourth take of add-hotplug-support patchset.  Changes from
This is the fifth take of prep-for-hotplug-support patchset.

Sorry.

-- 
tejun

Re: [PATCHSET 01/03] prep for hotplug support, take 5

[Jeff Garzik]

ACK entire patchset