[PATCH 2/2] libata: Add support for SATA attachment to SAS adapters

[PATCH 2/2] libata: Add support for SATA attachment to SAS adapters

[Brian King]

The following patch enhances libata to allow SAS device drivers
to utilize libata to talk to SATA devices. It introduces some
new APIs which allow libata to be used without allocating a
virtual scsi host.

New APIs:

ata_sas_port_alloc - Allocate an ata_port 
ata_sas_port_init - Initialize an ata_port (probe device, etc)
ata_sas_port_destroy - Free an ata_port allocated by ata_sas_port_alloc
ata_sas_slave_configure - configure scsi device
ata_sas_queuecmd - queue a scsi command, similar to ata_scsi_queuecomand

These new APIs can be used either directly by a SAS LLDD or could be used
by the SAS transport class. 

Possible usage for a SAS LLDD would be:

scsi_scan_host
	target_alloc
		ata_sas_port_alloc
	slave_alloc
		ata_sas_port_init
	slave_configure
		ata_sas_slave_configure

Commands received by the LLDD for SATA devices would call ata_sas_queuecmd.

Device teardown would occur with:

slave_destroy
	port_disable
target_destroy
	ata_sas_port_destroy

Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Brian King <brking@us.ibm.com>
---

 drivers/scsi/libata-core.c |    4 -
 drivers/scsi/libata-scsi.c |  166 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/scsi/libata.h      |    2 
 include/linux/libata.h     |    9 ++
 4 files changed, 179 insertions(+), 2 deletions(-)

diff -puN drivers/scsi/libata-scsi.c~libata_sas drivers/scsi/libata-scsi.c
--- libata-dev/drivers/scsi/libata-scsi.c~libata_sas	2006-07-09 13:07:22.000000000 -0500
+++ libata-dev-bjking1/drivers/scsi/libata-scsi.c	2006-07-09 13:07:22.000000000 -0500
@@ -3158,3 +3158,169 @@ void ata_scsi_dev_rescan(void *data)
 			scsi_rescan_device(&(dev->sdev->sdev_gendev));
 	}
 }
+
+/**
+ *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
+ *	@pdev: PCI device that the scsi device is attached to
+ *	@port_info: Information from low-level host driver
+ *	@host: SCSI host that the scsi device is attached to
+ *
+ *	LOCKING:
+ *	PCI/etc. bus probe sem.
+ *
+ *	RETURNS:
+ *	ata_port pointer on success / NULL on failure.
+ */
+
+struct ata_port *ata_sas_port_alloc(struct ata_host_set *host_set,
+				    struct ata_port_info *port_info,
+				    struct Scsi_Host *host)
+{
+	struct ata_port *ap = kzalloc(sizeof(*ap), GFP_KERNEL);
+	int i;
+
+	if (!ap)
+		return NULL;
+
+	ap->dev = host_set->dev;
+	ap->host_set = host_set;
+	ap->id = ata_unique_id++;
+	ap->lock = host->host_lock;
+	ap->ops = port_info->port_ops;
+	ap->flags = port_info->host_flags | ATA_FLAG_DISABLED;
+	ap->pio_mask = port_info->pio_mask;
+	ap->mwdma_mask = port_info->mwdma_mask;
+	ap->udma_mask = port_info->udma_mask;
+	ap->cbl = ATA_CBL_SATA;
+	ap->sata_spd_limit = UINT_MAX;
+	ap->active_tag = ATA_TAG_POISON;
+	ap->last_ctl = 0xFF;
+	INIT_WORK(&ap->port_task, NULL, NULL);
+	INIT_WORK(&ap->hotplug_task, ata_scsi_hotplug, ap);
+	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan, ap);
+	INIT_LIST_HEAD(&ap->eh_done_q);
+	init_waitqueue_head(&ap->eh_wait_q);
+
+	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);
+	}
+
+	return ap;
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
+
+/**
+ *	ata_sas_port_start - Set port up for dma.
+ *	@ap: Port to initialize
+ *
+ *	Called just after data structures for each port are
+ *	initialized.  Allocates DMA pad.
+ *
+ *	May be used as the port_start() entry in ata_port_operations.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+int ata_sas_port_start(struct ata_port *ap)
+{
+	return ata_pad_alloc(ap, ap->dev);
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_start);
+
+/**
+ *	ata_port_stop - Undo ata_sas_port_start()
+ *	@ap: Port to shut down
+ *
+ *	Frees the DMA pad.
+ *
+ *	May be used as the port_stop() entry in ata_port_operations.
+ *
+ *	LOCKING:
+ *	Inherited from caller.
+ */
+
+void ata_sas_port_stop(struct ata_port *ap)
+{
+	ata_pad_free(ap, ap->dev);
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_stop);
+
+/**
+ *	ata_sas_port_init - Initialize a SATA device
+ *	@ap: SATA port to initialize
+ *
+ *	LOCKING:
+ *	PCI/etc. bus probe sem.
+ *
+ *	RETURNS:
+ *	Zero on success, non-zero on error.
+ */
+
+int ata_sas_port_init(struct ata_port *ap)
+{
+	int rc = ap->ops->port_start(ap);
+
+	if (!rc)
+		rc = ata_bus_probe(ap);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_init);
+
+/**
+ *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
+ *	@ap: SATA port to destroy
+ *
+ */
+
+void ata_sas_port_destroy(struct ata_port *ap)
+{
+	ap->ops->port_stop(ap);
+	kfree(ap);
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_destroy);
+
+/**
+ *	ata_sas_slave_configure - Default slave_config routine for libata devices
+ *	@sdev: SCSI device to configure
+ *	@ap: ATA port to which SCSI device is attached
+ *
+ *	RETURNS:
+ *	Zero.
+ */
+
+int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
+{
+	ata_scsi_sdev_config(sdev);
+	ata_scsi_dev_config(sdev, ap->device);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ata_sas_slave_configure);
+
+/**
+ *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
+ *	@cmd: SCSI command to be sent
+ *	@done: Completion function, called when command is complete
+ *	@ap:	ATA port to which the command is being sent
+ *
+ *	RETURNS:
+ *	Zero.
+ */
+
+int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
+		     struct ata_port *ap)
+{
+	ata_scsi_dump_cdb(ap, cmd);
+
+	if (likely(ata_scsi_dev_enabled(ap->device)))
+		__ata_scsi_queuecmd(cmd, done, ap->device);
+	else {
+		cmd->result = (DID_BAD_TARGET << 16);
+		done(cmd);
+	}
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
diff -puN drivers/scsi/libata.h~libata_sas drivers/scsi/libata.h
--- libata-dev/drivers/scsi/libata.h~libata_sas	2006-07-09 13:07:22.000000000 -0500
+++ libata-dev-bjking1/drivers/scsi/libata.h	2006-07-09 13:07:22.000000000 -0500
@@ -43,6 +43,7 @@ extern struct workqueue_struct *ata_aux_
 extern int atapi_enabled;
 extern int atapi_dmadir;
 extern int libata_fua;
+extern unsigned int ata_unique_id;
 extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
 extern int ata_rwcmd_protocol(struct ata_queued_cmd *qc);
 extern void ata_dev_disable(struct ata_device *dev);
@@ -107,6 +108,7 @@ extern void ata_scsi_rbuf_fill(struct at
                                            u8 *rbuf, unsigned int buflen));
 extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
 extern void ata_scsi_dev_rescan(void *data);
+extern int ata_bus_probe(struct ata_port *ap);
 
 /* libata-eh.c */
 extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
diff -puN include/linux/libata.h~libata_sas include/linux/libata.h
--- libata-dev/include/linux/libata.h~libata_sas	2006-07-09 13:07:22.000000000 -0500
+++ libata-dev-bjking1/include/linux/libata.h	2006-07-09 13:07:22.000000000 -0500
@@ -689,6 +689,15 @@ extern int ata_scsi_detect(struct scsi_h
 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 void ata_sas_port_destroy(struct ata_port *);
+extern struct ata_port *ata_sas_port_alloc(struct ata_host_set *,
+					   struct ata_port_info *, struct Scsi_Host *);
+extern int ata_sas_port_init(struct ata_port *);
+extern int ata_sas_port_start(struct ata_port *ap);
+extern void ata_sas_port_stop(struct ata_port *ap);
+extern int ata_sas_slave_configure(struct scsi_device *, struct ata_port *);
+extern int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
+			    struct ata_port *ap);
 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);
diff -puN drivers/scsi/libata-core.c~libata_sas drivers/scsi/libata-core.c
--- libata-dev/drivers/scsi/libata-core.c~libata_sas	2006-07-09 13:07:22.000000000 -0500
+++ libata-dev-bjking1/drivers/scsi/libata-core.c	2006-07-09 13:07:22.000000000 -0500
@@ -70,7 +70,7 @@ static unsigned int ata_dev_init_params(
 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
 static void ata_dev_xfermask(struct ata_device *dev);
 
-static unsigned int ata_unique_id = 1;
+unsigned int ata_unique_id = 1;
 static struct workqueue_struct *ata_wq;
 
 struct workqueue_struct *ata_aux_wq;
@@ -1528,7 +1528,7 @@ err_out_nosup:
  *	Zero on success, negative errno otherwise.
  */
 
-static int ata_bus_probe(struct ata_port *ap)
+int ata_bus_probe(struct ata_port *ap)
 {
 	unsigned int classes[ATA_MAX_DEVICES];
 	int tries[ATA_MAX_DEVICES];
_

Re: [PATCH 2/2] libata: Add support for SATA attachment to SAS adapters

[Brian King]

Jeff,

Do you have any comments on my latest patches? What can I do to
help get this support merged into libata?


Here are some test results for the patchset:

1. sg3utils test to SATA/ATAPI device
   * Perform the following sg3utils commands to a SATA device:
       o sg_get_config
       o sginfo
       o sg_inq
       o sg_readcap
2. SATA error injection
   * Use sg_reset to initiate a PHY reset to a SATA device and verify
     the host recovers.
   * Use sysfs to reset the ipr adapter. This will cause the SATA device
     to receive an out of band PHY reset. Use sg_inq to issue an INQUIRY
     to the device. Verify error handling gets invoked and the system
     recovers.
3. stress_cd / internal CD/DVD exerciser (run for > 12 hours)
4. SLAB_DEBUG
   * Run with memory tainting enabled.
5. SATA add/remove device
   * Use sysfs to delete a SATA device from SCSI core, which will also
     cause the associated ATA port to get deleted.
   * Use sysfs to rescan for the SATA device. Verify the SATA device
     shows up again.
   * Verify no unexpected errors are logged.
6. SATA queue_depth
   * Use sysfs and attempt to change the queue depth of a SATA device.
   * Verify the queue depth stays at 1.

I would be happy to run any additional testcases.

Thanks,

Brian


Brian King wrote:
> The following patch enhances libata to allow SAS device drivers
> to utilize libata to talk to SATA devices. It introduces some
> new APIs which allow libata to be used without allocating a
> virtual scsi host.
> 
> New APIs:
> 
> ata_sas_port_alloc - Allocate an ata_port 
> ata_sas_port_init - Initialize an ata_port (probe device, etc)
> ata_sas_port_destroy - Free an ata_port allocated by ata_sas_port_alloc
> ata_sas_slave_configure - configure scsi device
> ata_sas_queuecmd - queue a scsi command, similar to ata_scsi_queuecomand
> 
> These new APIs can be used either directly by a SAS LLDD or could be used
> by the SAS transport class. 
> 
> Possible usage for a SAS LLDD would be:
> 
> scsi_scan_host
> 	target_alloc
> 		ata_sas_port_alloc
> 	slave_alloc
> 		ata_sas_port_init
> 	slave_configure
> 		ata_sas_slave_configure
> 
> Commands received by the LLDD for SATA devices would call ata_sas_queuecmd.
> 
> Device teardown would occur with:
> 
> slave_destroy
> 	port_disable
> target_destroy
> 	ata_sas_port_destroy
> 
> Acked-by: Jeff Garzik <jgarzik@pobox.com>
> Signed-off-by: Brian King <brking@us.ibm.com>
> ---
> 
>  drivers/scsi/libata-core.c |    4 -
>  drivers/scsi/libata-scsi.c |  166 +++++++++++++++++++++++++++++++++++++++++++++
>  drivers/scsi/libata.h      |    2 
>  include/linux/libata.h     |    9 ++
>  4 files changed, 179 insertions(+), 2 deletions(-)
> 
> diff -puN drivers/scsi/libata-scsi.c~libata_sas drivers/scsi/libata-scsi.c
> --- libata-dev/drivers/scsi/libata-scsi.c~libata_sas	2006-07-09 13:07:22.000000000 -0500
> +++ libata-dev-bjking1/drivers/scsi/libata-scsi.c	2006-07-09 13:07:22.000000000 -0500
> @@ -3158,3 +3158,169 @@ void ata_scsi_dev_rescan(void *data)
>  			scsi_rescan_device(&(dev->sdev->sdev_gendev));
>  	}
>  }
> +
> +/**
> + *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
> + *	@pdev: PCI device that the scsi device is attached to
> + *	@port_info: Information from low-level host driver
> + *	@host: SCSI host that the scsi device is attached to
> + *
> + *	LOCKING:
> + *	PCI/etc. bus probe sem.
> + *
> + *	RETURNS:
> + *	ata_port pointer on success / NULL on failure.
> + */
> +
> +struct ata_port *ata_sas_port_alloc(struct ata_host_set *host_set,
> +				    struct ata_port_info *port_info,
> +				    struct Scsi_Host *host)
> +{
> +	struct ata_port *ap = kzalloc(sizeof(*ap), GFP_KERNEL);
> +	int i;
> +
> +	if (!ap)
> +		return NULL;
> +
> +	ap->dev = host_set->dev;
> +	ap->host_set = host_set;
> +	ap->id = ata_unique_id++;
> +	ap->lock = host->host_lock;
> +	ap->ops = port_info->port_ops;
> +	ap->flags = port_info->host_flags | ATA_FLAG_DISABLED;
> +	ap->pio_mask = port_info->pio_mask;
> +	ap->mwdma_mask = port_info->mwdma_mask;
> +	ap->udma_mask = port_info->udma_mask;
> +	ap->cbl = ATA_CBL_SATA;
> +	ap->sata_spd_limit = UINT_MAX;
> +	ap->active_tag = ATA_TAG_POISON;
> +	ap->last_ctl = 0xFF;
> +	INIT_WORK(&ap->port_task, NULL, NULL);
> +	INIT_WORK(&ap->hotplug_task, ata_scsi_hotplug, ap);
> +	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan, ap);
> +	INIT_LIST_HEAD(&ap->eh_done_q);
> +	init_waitqueue_head(&ap->eh_wait_q);
> +
> +	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);
> +	}
> +
> +	return ap;
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
> +
> +/**
> + *	ata_sas_port_start - Set port up for dma.
> + *	@ap: Port to initialize
> + *
> + *	Called just after data structures for each port are
> + *	initialized.  Allocates DMA pad.
> + *
> + *	May be used as the port_start() entry in ata_port_operations.
> + *
> + *	LOCKING:
> + *	Inherited from caller.
> + */
> +int ata_sas_port_start(struct ata_port *ap)
> +{
> +	return ata_pad_alloc(ap, ap->dev);
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_port_start);
> +
> +/**
> + *	ata_port_stop - Undo ata_sas_port_start()
> + *	@ap: Port to shut down
> + *
> + *	Frees the DMA pad.
> + *
> + *	May be used as the port_stop() entry in ata_port_operations.
> + *
> + *	LOCKING:
> + *	Inherited from caller.
> + */
> +
> +void ata_sas_port_stop(struct ata_port *ap)
> +{
> +	ata_pad_free(ap, ap->dev);
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_port_stop);
> +
> +/**
> + *	ata_sas_port_init - Initialize a SATA device
> + *	@ap: SATA port to initialize
> + *
> + *	LOCKING:
> + *	PCI/etc. bus probe sem.
> + *
> + *	RETURNS:
> + *	Zero on success, non-zero on error.
> + */
> +
> +int ata_sas_port_init(struct ata_port *ap)
> +{
> +	int rc = ap->ops->port_start(ap);
> +
> +	if (!rc)
> +		rc = ata_bus_probe(ap);
> +
> +	return rc;
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_port_init);
> +
> +/**
> + *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
> + *	@ap: SATA port to destroy
> + *
> + */
> +
> +void ata_sas_port_destroy(struct ata_port *ap)
> +{
> +	ap->ops->port_stop(ap);
> +	kfree(ap);
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_port_destroy);
> +
> +/**
> + *	ata_sas_slave_configure - Default slave_config routine for libata devices
> + *	@sdev: SCSI device to configure
> + *	@ap: ATA port to which SCSI device is attached
> + *
> + *	RETURNS:
> + *	Zero.
> + */
> +
> +int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
> +{
> +	ata_scsi_sdev_config(sdev);
> +	ata_scsi_dev_config(sdev, ap->device);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_slave_configure);
> +
> +/**
> + *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
> + *	@cmd: SCSI command to be sent
> + *	@done: Completion function, called when command is complete
> + *	@ap:	ATA port to which the command is being sent
> + *
> + *	RETURNS:
> + *	Zero.
> + */
> +
> +int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
> +		     struct ata_port *ap)
> +{
> +	ata_scsi_dump_cdb(ap, cmd);
> +
> +	if (likely(ata_scsi_dev_enabled(ap->device)))
> +		__ata_scsi_queuecmd(cmd, done, ap->device);
> +	else {
> +		cmd->result = (DID_BAD_TARGET << 16);
> +		done(cmd);
> +	}
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
> diff -puN drivers/scsi/libata.h~libata_sas drivers/scsi/libata.h
> --- libata-dev/drivers/scsi/libata.h~libata_sas	2006-07-09 13:07:22.000000000 -0500
> +++ libata-dev-bjking1/drivers/scsi/libata.h	2006-07-09 13:07:22.000000000 -0500
> @@ -43,6 +43,7 @@ extern struct workqueue_struct *ata_aux_
>  extern int atapi_enabled;
>  extern int atapi_dmadir;
>  extern int libata_fua;
> +extern unsigned int ata_unique_id;
>  extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
>  extern int ata_rwcmd_protocol(struct ata_queued_cmd *qc);
>  extern void ata_dev_disable(struct ata_device *dev);
> @@ -107,6 +108,7 @@ extern void ata_scsi_rbuf_fill(struct at
>                                             u8 *rbuf, unsigned int buflen));
>  extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
>  extern void ata_scsi_dev_rescan(void *data);
> +extern int ata_bus_probe(struct ata_port *ap);
>  
>  /* libata-eh.c */
>  extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
> diff -puN include/linux/libata.h~libata_sas include/linux/libata.h
> --- libata-dev/include/linux/libata.h~libata_sas	2006-07-09 13:07:22.000000000 -0500
> +++ libata-dev-bjking1/include/linux/libata.h	2006-07-09 13:07:22.000000000 -0500
> @@ -689,6 +689,15 @@ extern int ata_scsi_detect(struct scsi_h
>  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 void ata_sas_port_destroy(struct ata_port *);
> +extern struct ata_port *ata_sas_port_alloc(struct ata_host_set *,
> +					   struct ata_port_info *, struct Scsi_Host *);
> +extern int ata_sas_port_init(struct ata_port *);
> +extern int ata_sas_port_start(struct ata_port *ap);
> +extern void ata_sas_port_stop(struct ata_port *ap);
> +extern int ata_sas_slave_configure(struct scsi_device *, struct ata_port *);
> +extern int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
> +			    struct ata_port *ap);
>  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);
> diff -puN drivers/scsi/libata-core.c~libata_sas drivers/scsi/libata-core.c
> --- libata-dev/drivers/scsi/libata-core.c~libata_sas	2006-07-09 13:07:22.000000000 -0500
> +++ libata-dev-bjking1/drivers/scsi/libata-core.c	2006-07-09 13:07:22.000000000 -0500
> @@ -70,7 +70,7 @@ static unsigned int ata_dev_init_params(
>  static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
>  static void ata_dev_xfermask(struct ata_device *dev);
>  
> -static unsigned int ata_unique_id = 1;
> +unsigned int ata_unique_id = 1;
>  static struct workqueue_struct *ata_wq;
>  
>  struct workqueue_struct *ata_aux_wq;
> @@ -1528,7 +1528,7 @@ err_out_nosup:
>   *	Zero on success, negative errno otherwise.
>   */
>  
> -static int ata_bus_probe(struct ata_port *ap)
> +int ata_bus_probe(struct ata_port *ap)
>  {
>  	unsigned int classes[ATA_MAX_DEVICES];
>  	int tries[ATA_MAX_DEVICES];
> _

Re: [PATCH 2/2] libata: Add support for SATA attachment to SAS adapters

[Brian King]

Ping

Brian King wrote:
> Jeff,
> 
> Do you have any comments on my latest patches? What can I do to
> help get this support merged into libata?
> 
> 
> Here are some test results for the patchset:
> 
> 1. sg3utils test to SATA/ATAPI device
>    * Perform the following sg3utils commands to a SATA device:
>        o sg_get_config
>        o sginfo
>        o sg_inq
>        o sg_readcap
> 2. SATA error injection
>    * Use sg_reset to initiate a PHY reset to a SATA device and verify
>      the host recovers.
>    * Use sysfs to reset the ipr adapter. This will cause the SATA device
>      to receive an out of band PHY reset. Use sg_inq to issue an INQUIRY
>      to the device. Verify error handling gets invoked and the system
>      recovers.
> 3. stress_cd / internal CD/DVD exerciser (run for > 12 hours)
> 4. SLAB_DEBUG
>    * Run with memory tainting enabled.
> 5. SATA add/remove device
>    * Use sysfs to delete a SATA device from SCSI core, which will also
>      cause the associated ATA port to get deleted.
>    * Use sysfs to rescan for the SATA device. Verify the SATA device
>      shows up again.
>    * Verify no unexpected errors are logged.
> 6. SATA queue_depth
>    * Use sysfs and attempt to change the queue depth of a SATA device.
>    * Verify the queue depth stays at 1.
> 
> I would be happy to run any additional testcases.
> 
> Thanks,
> 
> Brian
> 
> 
> Brian King wrote:
>> The following patch enhances libata to allow SAS device drivers
>> to utilize libata to talk to SATA devices. It introduces some
>> new APIs which allow libata to be used without allocating a
>> virtual scsi host.
>>
>> New APIs:
>>
>> ata_sas_port_alloc - Allocate an ata_port 
>> ata_sas_port_init - Initialize an ata_port (probe device, etc)
>> ata_sas_port_destroy - Free an ata_port allocated by ata_sas_port_alloc
>> ata_sas_slave_configure - configure scsi device
>> ata_sas_queuecmd - queue a scsi command, similar to ata_scsi_queuecomand
>>
>> These new APIs can be used either directly by a SAS LLDD or could be used
>> by the SAS transport class. 
>>
>> Possible usage for a SAS LLDD would be:
>>
>> scsi_scan_host
>> 	target_alloc
>> 		ata_sas_port_alloc
>> 	slave_alloc
>> 		ata_sas_port_init
>> 	slave_configure
>> 		ata_sas_slave_configure
>>
>> Commands received by the LLDD for SATA devices would call ata_sas_queuecmd.
>>
>> Device teardown would occur with:
>>
>> slave_destroy
>> 	port_disable
>> target_destroy
>> 	ata_sas_port_destroy
>>
>> Acked-by: Jeff Garzik <jgarzik@pobox.com>
>> Signed-off-by: Brian King <brking@us.ibm.com>
>> ---
>>
>>  drivers/scsi/libata-core.c |    4 -
>>  drivers/scsi/libata-scsi.c |  166 +++++++++++++++++++++++++++++++++++++++++++++
>>  drivers/scsi/libata.h      |    2 
>>  include/linux/libata.h     |    9 ++
>>  4 files changed, 179 insertions(+), 2 deletions(-)
>>
>> diff -puN drivers/scsi/libata-scsi.c~libata_sas drivers/scsi/libata-scsi.c
>> --- libata-dev/drivers/scsi/libata-scsi.c~libata_sas	2006-07-09 13:07:22.000000000 -0500
>> +++ libata-dev-bjking1/drivers/scsi/libata-scsi.c	2006-07-09 13:07:22.000000000 -0500
>> @@ -3158,3 +3158,169 @@ void ata_scsi_dev_rescan(void *data)
>>  			scsi_rescan_device(&(dev->sdev->sdev_gendev));
>>  	}
>>  }
>> +
>> +/**
>> + *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
>> + *	@pdev: PCI device that the scsi device is attached to
>> + *	@port_info: Information from low-level host driver
>> + *	@host: SCSI host that the scsi device is attached to
>> + *
>> + *	LOCKING:
>> + *	PCI/etc. bus probe sem.
>> + *
>> + *	RETURNS:
>> + *	ata_port pointer on success / NULL on failure.
>> + */
>> +
>> +struct ata_port *ata_sas_port_alloc(struct ata_host_set *host_set,
>> +				    struct ata_port_info *port_info,
>> +				    struct Scsi_Host *host)
>> +{
>> +	struct ata_port *ap = kzalloc(sizeof(*ap), GFP_KERNEL);
>> +	int i;
>> +
>> +	if (!ap)
>> +		return NULL;
>> +
>> +	ap->dev = host_set->dev;
>> +	ap->host_set = host_set;
>> +	ap->id = ata_unique_id++;
>> +	ap->lock = host->host_lock;
>> +	ap->ops = port_info->port_ops;
>> +	ap->flags = port_info->host_flags | ATA_FLAG_DISABLED;
>> +	ap->pio_mask = port_info->pio_mask;
>> +	ap->mwdma_mask = port_info->mwdma_mask;
>> +	ap->udma_mask = port_info->udma_mask;
>> +	ap->cbl = ATA_CBL_SATA;
>> +	ap->sata_spd_limit = UINT_MAX;
>> +	ap->active_tag = ATA_TAG_POISON;
>> +	ap->last_ctl = 0xFF;
>> +	INIT_WORK(&ap->port_task, NULL, NULL);
>> +	INIT_WORK(&ap->hotplug_task, ata_scsi_hotplug, ap);
>> +	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan, ap);
>> +	INIT_LIST_HEAD(&ap->eh_done_q);
>> +	init_waitqueue_head(&ap->eh_wait_q);
>> +
>> +	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);
>> +	}
>> +
>> +	return ap;
>> +}
>> +EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
>> +
>> +/**
>> + *	ata_sas_port_start - Set port up for dma.
>> + *	@ap: Port to initialize
>> + *
>> + *	Called just after data structures for each port are
>> + *	initialized.  Allocates DMA pad.
>> + *
>> + *	May be used as the port_start() entry in ata_port_operations.
>> + *
>> + *	LOCKING:
>> + *	Inherited from caller.
>> + */
>> +int ata_sas_port_start(struct ata_port *ap)
>> +{
>> +	return ata_pad_alloc(ap, ap->dev);
>> +}
>> +EXPORT_SYMBOL_GPL(ata_sas_port_start);
>> +
>> +/**
>> + *	ata_port_stop - Undo ata_sas_port_start()
>> + *	@ap: Port to shut down
>> + *
>> + *	Frees the DMA pad.
>> + *
>> + *	May be used as the port_stop() entry in ata_port_operations.
>> + *
>> + *	LOCKING:
>> + *	Inherited from caller.
>> + */
>> +
>> +void ata_sas_port_stop(struct ata_port *ap)
>> +{
>> +	ata_pad_free(ap, ap->dev);
>> +}
>> +EXPORT_SYMBOL_GPL(ata_sas_port_stop);
>> +
>> +/**
>> + *	ata_sas_port_init - Initialize a SATA device
>> + *	@ap: SATA port to initialize
>> + *
>> + *	LOCKING:
>> + *	PCI/etc. bus probe sem.
>> + *
>> + *	RETURNS:
>> + *	Zero on success, non-zero on error.
>> + */
>> +
>> +int ata_sas_port_init(struct ata_port *ap)
>> +{
>> +	int rc = ap->ops->port_start(ap);
>> +
>> +	if (!rc)
>> +		rc = ata_bus_probe(ap);
>> +
>> +	return rc;
>> +}
>> +EXPORT_SYMBOL_GPL(ata_sas_port_init);
>> +
>> +/**
>> + *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
>> + *	@ap: SATA port to destroy
>> + *
>> + */
>> +
>> +void ata_sas_port_destroy(struct ata_port *ap)
>> +{
>> +	ap->ops->port_stop(ap);
>> +	kfree(ap);
>> +}
>> +EXPORT_SYMBOL_GPL(ata_sas_port_destroy);
>> +
>> +/**
>> + *	ata_sas_slave_configure - Default slave_config routine for libata devices
>> + *	@sdev: SCSI device to configure
>> + *	@ap: ATA port to which SCSI device is attached
>> + *
>> + *	RETURNS:
>> + *	Zero.
>> + */
>> +
>> +int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
>> +{
>> +	ata_scsi_sdev_config(sdev);
>> +	ata_scsi_dev_config(sdev, ap->device);
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(ata_sas_slave_configure);
>> +
>> +/**
>> + *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
>> + *	@cmd: SCSI command to be sent
>> + *	@done: Completion function, called when command is complete
>> + *	@ap:	ATA port to which the command is being sent
>> + *
>> + *	RETURNS:
>> + *	Zero.
>> + */
>> +
>> +int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
>> +		     struct ata_port *ap)
>> +{
>> +	ata_scsi_dump_cdb(ap, cmd);
>> +
>> +	if (likely(ata_scsi_dev_enabled(ap->device)))
>> +		__ata_scsi_queuecmd(cmd, done, ap->device);
>> +	else {
>> +		cmd->result = (DID_BAD_TARGET << 16);
>> +		done(cmd);
>> +	}
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
>> diff -puN drivers/scsi/libata.h~libata_sas drivers/scsi/libata.h
>> --- libata-dev/drivers/scsi/libata.h~libata_sas	2006-07-09 13:07:22.000000000 -0500
>> +++ libata-dev-bjking1/drivers/scsi/libata.h	2006-07-09 13:07:22.000000000 -0500
>> @@ -43,6 +43,7 @@ extern struct workqueue_struct *ata_aux_
>>  extern int atapi_enabled;
>>  extern int atapi_dmadir;
>>  extern int libata_fua;
>> +extern unsigned int ata_unique_id;
>>  extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev);
>>  extern int ata_rwcmd_protocol(struct ata_queued_cmd *qc);
>>  extern void ata_dev_disable(struct ata_device *dev);
>> @@ -107,6 +108,7 @@ extern void ata_scsi_rbuf_fill(struct at
>>                                             u8 *rbuf, unsigned int buflen));
>>  extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
>>  extern void ata_scsi_dev_rescan(void *data);
>> +extern int ata_bus_probe(struct ata_port *ap);
>>  
>>  /* libata-eh.c */
>>  extern enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd);
>> diff -puN include/linux/libata.h~libata_sas include/linux/libata.h
>> --- libata-dev/include/linux/libata.h~libata_sas	2006-07-09 13:07:22.000000000 -0500
>> +++ libata-dev-bjking1/include/linux/libata.h	2006-07-09 13:07:22.000000000 -0500
>> @@ -689,6 +689,15 @@ extern int ata_scsi_detect(struct scsi_h
>>  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 void ata_sas_port_destroy(struct ata_port *);
>> +extern struct ata_port *ata_sas_port_alloc(struct ata_host_set *,
>> +					   struct ata_port_info *, struct Scsi_Host *);
>> +extern int ata_sas_port_init(struct ata_port *);
>> +extern int ata_sas_port_start(struct ata_port *ap);
>> +extern void ata_sas_port_stop(struct ata_port *ap);
>> +extern int ata_sas_slave_configure(struct scsi_device *, struct ata_port *);
>> +extern int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
>> +			    struct ata_port *ap);
>>  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);
>> diff -puN drivers/scsi/libata-core.c~libata_sas drivers/scsi/libata-core.c
>> --- libata-dev/drivers/scsi/libata-core.c~libata_sas	2006-07-09 13:07:22.000000000 -0500
>> +++ libata-dev-bjking1/drivers/scsi/libata-core.c	2006-07-09 13:07:22.000000000 -0500
>> @@ -70,7 +70,7 @@ static unsigned int ata_dev_init_params(
>>  static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
>>  static void ata_dev_xfermask(struct ata_device *dev);
>>  
>> -static unsigned int ata_unique_id = 1;
>> +unsigned int ata_unique_id = 1;
>>  static struct workqueue_struct *ata_wq;
>>  
>>  struct workqueue_struct *ata_aux_wq;
>> @@ -1528,7 +1528,7 @@ err_out_nosup:
>>   *	Zero on success, negative errno otherwise.
>>   */
>>  
>> -static int ata_bus_probe(struct ata_port *ap)
>> +int ata_bus_probe(struct ata_port *ap)
>>  {
>>  	unsigned int classes[ATA_MAX_DEVICES];
>>  	int tries[ATA_MAX_DEVICES];
>> _
> 


-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center

Re: [PATCH 2/2] libata: Add support for SATA attachment to SAS adapters

[Jeff Garzik]

You shouldn't be duplicating all that init code from ata_host_init().

Fix that issue (presumably by factoring out common code), and I'll apply 
this SAS<->SATA attachment API patchset.

	Jeff

[RFC 0/2] libata: support SATA devices on SAS HBAs

[Brian King]

The following patches enhance libata to allow SAS device drivers
to utilize libata to talk to SATA devices. It introduces some
new APIs which allow libata to be used without allocating a
virtual scsi host. This is just a snapshot of what I've
come up with at this point and I figured I would post it to
see if I was heading in a reasonable direction or not, so
don't expect the code below to do anything useful at this point
as it is untested.

New APIs:

ata_sas_port_alloc - Allocate an ata_port 
ata_sas_port_init - Initialize an ata_port (probe bus, etc)
ata_sas_port_destroy - Free an ata_port allocated by ata_sas_port_alloc
ata_sas_slave_configure - configure scsi device
ata_sas_queuecmd - queue a scsi command, similar to ata_scsi_queuecomand

These new APIs can be used either directly by a SAS LLDD or could be used
by the SAS transport class. 

Possible usage for a SAS LLDD would be:

scsi_scan_host
	slave_alloc
		ata_sas_port_alloc
		ata_sas_port_init
	slave_configure
		ata_sas_slave_configure

Commands received by the LLDD for SATA devices would call ata_sas_queuecmd.

Device teardown would occur with:

slave_destroy
	ata_sas_port_destroy


-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center

Re: [RFC 0/2] libata: support SATA devices on SAS HBAs

[Jeff Garzik]

Brian King wrote:
> The following patches enhance libata to allow SAS device drivers
> to utilize libata to talk to SATA devices. It introduces some
> new APIs which allow libata to be used without allocating a
> virtual scsi host. This is just a snapshot of what I've
> come up with at this point and I figured I would post it to
> see if I was heading in a reasonable direction or not, so
> don't expect the code below to do anything useful at this point
> as it is untested.

hmmmm, neat.  My gut feeling feeling says a slightly better direction 
might be warranted, but I'll have to think a bit to put that feeling 
towords.

* One thought is the desire to allocate a single ata_host_set for the 
HBA, rather than avoiding ata_host_set.
* Another thought is the locking scheme -- Christoph once poked me about 
libata's use of scsi_assign_lock(), which I rather like but he didn't :) 
  So by the transitive(?) property, if libata's locking is useful, then 
your solution is probably OK.  And vice versa.
* I also wonder if there isn't any severe leakage or oops somewhere, 
because you don't really use ata_host_set, just ata_port.

But note again, these are 6am thoughts, not in-depth analysis.

	Jeff

Re: [RFC 0/2] libata: support SATA devices on SAS HBAs

[Bartlomiej Zolnierkiewicz]

On 10/4/05, Jeff Garzik <jgarzik@pobox.com> wrote:
> Brian King wrote:
> > The following patches enhance libata to allow SAS device drivers
> > to utilize libata to talk to SATA devices. It introduces some
> > new APIs which allow libata to be used without allocating a
> > virtual scsi host. This is just a snapshot of what I've
> > come up with at this point and I figured I would post it to
> > see if I was heading in a reasonable direction or not, so
> > don't expect the code below to do anything useful at this point
> > as it is untested.
>
> hmmmm, neat.  My gut feeling feeling says a slightly better direction
> might be warranted, but I'll have to think a bit to put that feeling
> towords.
>
> * One thought is the desire to allocate a single ata_host_set for the
> HBA, rather than avoiding ata_host_set.

For SAS we should definitely avoid ata_host_set.

> * Another thought is the locking scheme -- Christoph once poked me about
> libata's use of scsi_assign_lock(), which I rather like but he didn't :)
>   So by the transitive(?) property, if libata's locking is useful, then
> your solution is probably OK.  And vice versa.

host_set->lock is not useful for SAS et all and libata can
be easily fixed to not require it for SAS (I'll make a patch later).

> * I also wonder if there isn't any severe leakage or oops somewhere,
> because you don't really use ata_host_set, just ata_port.
>
> But note again, these are 6am thoughts, not in-depth analysis.

:)

Bartlomiej

Re: [RFC 0/2] libata: support SATA devices on SAS HBAs

[Bartlomiej Zolnierkiewicz]

[-- Attachment #1: Type: text/plain, Size: 1751 bytes --]

On 10/4/05, Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> wrote:
> On 10/4/05, Jeff Garzik <jgarzik@pobox.com> wrote:
> > Brian King wrote:
> > > The following patches enhance libata to allow SAS device drivers
> > > to utilize libata to talk to SATA devices. It introduces some
> > > new APIs which allow libata to be used without allocating a
> > > virtual scsi host. This is just a snapshot of what I've
> > > come up with at this point and I figured I would post it to
> > > see if I was heading in a reasonable direction or not, so
> > > don't expect the code below to do anything useful at this point
> > > as it is untested.
> >
> > hmmmm, neat.  My gut feeling feeling says a slightly better direction
> > might be warranted, but I'll have to think a bit to put that feeling
> > towords.
> >
> > * One thought is the desire to allocate a single ata_host_set for the
> > HBA, rather than avoiding ata_host_set.
>
> For SAS we should definitely avoid ata_host_set.
>
> > * Another thought is the locking scheme -- Christoph once poked me about
> > libata's use of scsi_assign_lock(), which I rather like but he didn't :)
> >   So by the transitive(?) property, if libata's locking is useful, then
> > your solution is probably OK.  And vice versa.
>
> host_set->lock is not useful for SAS et all and libata can
> be easily fixed to not require it for SAS (I'll make a patch later).

Attached (sorry for that but I needed to push it through gmail).

Please note that all other usages of host_set->lock are dependent on
existence of hardware (S)ATA port which is simply not a case for SAS.
We can also avoid using host_set entirely by allowing SAS layer to only
register struct ata_port.

Thanks,
Bartlomiej

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: libata-qc_transport.patch --]
[-- Type: text/x-patch; name="libata-qc_transport.patch", Size: 10383 bytes --]

[PATCH] libata: add ops->qc_transport for SAS

* add ->qc_transport to struct ata_port_operations
* add default ata_qc_transport() and update all host drivers

Thanks to this change we won't have to depend on host_set
and host_set->lock for devices attached to SAS HBAs.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

Index: libata-dev/drivers/scsi/libata-core.c
===================================================================
--- libata-dev.orig/drivers/scsi/libata-core.c
+++ libata-dev/drivers/scsi/libata-core.c
@@ -1138,7 +1138,6 @@ static void ata_dev_identify(struct ata_
 	unsigned int using_edd;
 	DECLARE_COMPLETION(wait);
 	struct ata_queued_cmd *qc;
-	unsigned long flags;
 	int rc;
 
 	if (!ata_dev_present(dev)) {
@@ -1179,9 +1178,7 @@ retry:
 	qc->waiting = &wait;
 	qc->complete_fn = ata_qc_complete_noop;
 
-	spin_lock_irqsave(&ap->host_set->lock, flags);
-	rc = ata_qc_issue(qc);
-	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+	rc = ap->ops->qc_transport(qc);
 
 	if (rc)
 		goto err_out;
@@ -2114,7 +2111,6 @@ static void ata_dev_set_xfermode(struct 
 	DECLARE_COMPLETION(wait);
 	struct ata_queued_cmd *qc;
 	int rc;
-	unsigned long flags;
 
 	/* set up set-features taskfile */
 	DPRINTK("set features - xfer mode\n");
@@ -2131,9 +2127,7 @@ static void ata_dev_set_xfermode(struct 
 	qc->waiting = &wait;
 	qc->complete_fn = ata_qc_complete_noop;
 
-	spin_lock_irqsave(&ap->host_set->lock, flags);
-	rc = ata_qc_issue(qc);
-	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+	rc = ap->ops->qc_transport(qc);
 
 	if (rc)
 		ata_port_disable(ap);
@@ -2933,7 +2927,6 @@ static void atapi_request_sense(struct a
 {
 	DECLARE_COMPLETION(wait);
 	struct ata_queued_cmd *qc;
-	unsigned long flags;
 	int rc;
 
 	DPRINTK("ATAPI request sense\n");
@@ -2962,9 +2955,7 @@ static void atapi_request_sense(struct a
 	qc->waiting = &wait;
 	qc->complete_fn = ata_qc_complete_noop;
 
-	spin_lock_irqsave(&ap->host_set->lock, flags);
-	rc = ata_qc_issue(qc);
-	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+	rc = ap->ops->qc_transport(qc);
 
 	if (rc)
 		ata_port_disable(ap);
@@ -3321,6 +3312,29 @@ err_out:
 	return -1;
 }
 
+/**
+ *	ata_qc_transport - transport taskfile to device
+ *	@qc: command to issue to device
+ *
+ *	LOCKING:
+ *	Obtains host_set lock.
+ *
+ *	RETURNS:
+ *	Zero on success, negative on error.
+ */
+
+int ata_qc_transport(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+	unsigned long flags;
+	int rc;
+
+	spin_lock_irqsave(&ap->host_set->lock, flags);
+	rc = ata_qc_issue(qc);
+	spin_unlock_irqrestore(&ap->host_set->lock, flags);
+
+	return rc;
+}
 
 /**
  *	ata_qc_issue_prot - issue taskfile to device in proto-dependent manner
@@ -4593,6 +4607,7 @@ EXPORT_SYMBOL_GPL(ata_host_set_remove);
 EXPORT_SYMBOL_GPL(ata_sg_init);
 EXPORT_SYMBOL_GPL(ata_sg_init_one);
 EXPORT_SYMBOL_GPL(ata_qc_complete);
+EXPORT_SYMBOL_GPL(ata_qc_transport);
 EXPORT_SYMBOL_GPL(ata_qc_issue_prot);
 EXPORT_SYMBOL_GPL(ata_eng_timeout);
 EXPORT_SYMBOL_GPL(ata_tf_load);
Index: libata-dev/include/linux/libata.h
===================================================================
--- libata-dev.orig/include/linux/libata.h
+++ libata-dev/include/linux/libata.h
@@ -352,6 +352,7 @@ struct ata_port_operations {
 
 	void (*qc_prep) (struct ata_queued_cmd *qc);
 	int (*qc_issue) (struct ata_queued_cmd *qc);
+	int (*qc_transport) (struct ata_queued_cmd *qc);
 
 	void (*eng_timeout) (struct ata_port *ap);
 
@@ -419,6 +420,7 @@ extern void ata_host_stop (struct ata_ho
 extern irqreturn_t ata_interrupt (int irq, void *dev_instance, struct pt_regs *regs);
 extern void ata_qc_prep(struct ata_queued_cmd *qc);
 extern int ata_qc_issue_prot(struct ata_queued_cmd *qc);
+extern int ata_qc_transport(struct ata_queued_cmd *qc);
 extern void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf,
 		unsigned int buflen);
 extern void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
Index: libata-dev/drivers/scsi/ahci.c
===================================================================
--- libata-dev.orig/drivers/scsi/ahci.c
+++ libata-dev/drivers/scsi/ahci.c
@@ -230,6 +230,7 @@ static struct ata_port_operations ahci_o
 
 	.qc_prep		= ahci_qc_prep,
 	.qc_issue		= ahci_qc_issue,
+	.qc_transport		= ata_qc_transport,
 
 	.eng_timeout		= ahci_eng_timeout,
 
Index: libata-dev/drivers/scsi/ata_piix.c
===================================================================
--- libata-dev.orig/drivers/scsi/ata_piix.c
+++ libata-dev/drivers/scsi/ata_piix.c
@@ -166,6 +166,7 @@ static struct ata_port_operations piix_p
 	.bmdma_status		= ata_bmdma_status,
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 
 	.eng_timeout		= ata_eng_timeout,
 
@@ -194,6 +195,7 @@ static struct ata_port_operations piix_s
 	.bmdma_status		= ata_bmdma_status,
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 
 	.eng_timeout		= ata_eng_timeout,
 
Index: libata-dev/drivers/scsi/sata_mv.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_mv.c
+++ libata-dev/drivers/scsi/sata_mv.c
@@ -223,6 +223,7 @@ static struct ata_port_operations mv_ops
 
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 
 	.eng_timeout		= ata_eng_timeout,
 
Index: libata-dev/drivers/scsi/sata_nv.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_nv.c
+++ libata-dev/drivers/scsi/sata_nv.c
@@ -252,6 +252,7 @@ static struct ata_port_operations nv_ops
 	.bmdma_status		= ata_bmdma_status,
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= nv_interrupt,
 	.irq_clear		= ata_bmdma_irq_clear,
Index: libata-dev/drivers/scsi/sata_promise.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_promise.c
+++ libata-dev/drivers/scsi/sata_promise.c
@@ -125,6 +125,7 @@ static struct ata_port_operations pdc_sa
 
 	.qc_prep		= pdc_qc_prep,
 	.qc_issue		= pdc_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 	.eng_timeout		= pdc_eng_timeout,
 	.irq_handler		= pdc_interrupt,
 	.irq_clear		= pdc_irq_clear,
@@ -148,6 +149,7 @@ static struct ata_port_operations pdc_pa
 
 	.qc_prep		= pdc_qc_prep,
 	.qc_issue		= pdc_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 	.eng_timeout		= pdc_eng_timeout,
 	.irq_handler		= pdc_interrupt,
 	.irq_clear		= pdc_irq_clear,
Index: libata-dev/drivers/scsi/sata_qstor.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_qstor.c
+++ libata-dev/drivers/scsi/sata_qstor.c
@@ -156,6 +156,7 @@ static struct ata_port_operations qs_ata
 	.phy_reset		= qs_phy_reset,
 	.qc_prep		= qs_qc_prep,
 	.qc_issue		= qs_qc_issue,
+	.qc_transport		= ata_qc_transport,
 	.eng_timeout		= qs_eng_timeout,
 	.irq_handler		= qs_intr,
 	.irq_clear		= qs_irq_clear,
Index: libata-dev/drivers/scsi/sata_sil.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_sil.c
+++ libata-dev/drivers/scsi/sata_sil.c
@@ -166,6 +166,7 @@ static struct ata_port_operations sil_op
 	.bmdma_status		= ata_bmdma_status,
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= ata_interrupt,
 	.irq_clear		= ata_bmdma_irq_clear,
Index: libata-dev/drivers/scsi/sata_sis.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_sis.c
+++ libata-dev/drivers/scsi/sata_sis.c
@@ -116,6 +116,7 @@ static struct ata_port_operations sis_op
 	.bmdma_status		= ata_bmdma_status,
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= ata_interrupt,
 	.irq_clear		= ata_bmdma_irq_clear,
Index: libata-dev/drivers/scsi/sata_svw.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_svw.c
+++ libata-dev/drivers/scsi/sata_svw.c
@@ -311,6 +311,7 @@ static struct ata_port_operations k2_sat
 	.bmdma_status		= ata_bmdma_status,
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= ata_interrupt,
 	.irq_clear		= ata_bmdma_irq_clear,
Index: libata-dev/drivers/scsi/sata_sx4.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_sx4.c
+++ libata-dev/drivers/scsi/sata_sx4.c
@@ -206,6 +206,7 @@ static struct ata_port_operations pdc_20
 	.phy_reset		= pdc_20621_phy_reset,
 	.qc_prep		= pdc20621_qc_prep,
 	.qc_issue		= pdc20621_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 	.eng_timeout		= pdc_eng_timeout,
 	.irq_handler		= pdc20621_interrupt,
 	.irq_clear		= pdc20621_irq_clear,
Index: libata-dev/drivers/scsi/sata_uli.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_uli.c
+++ libata-dev/drivers/scsi/sata_uli.c
@@ -107,6 +107,7 @@ static struct ata_port_operations uli_op
 	.bmdma_status		= ata_bmdma_status,
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 
 	.eng_timeout		= ata_eng_timeout,
 
Index: libata-dev/drivers/scsi/sata_via.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_via.c
+++ libata-dev/drivers/scsi/sata_via.c
@@ -127,6 +127,7 @@ static struct ata_port_operations svia_s
 
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 
 	.eng_timeout		= ata_eng_timeout,
 
Index: libata-dev/drivers/scsi/sata_vsc.c
===================================================================
--- libata-dev.orig/drivers/scsi/sata_vsc.c
+++ libata-dev/drivers/scsi/sata_vsc.c
@@ -245,6 +245,7 @@ static struct ata_port_operations vsc_sa
 	.bmdma_status		= ata_bmdma_status,
 	.qc_prep		= ata_qc_prep,
 	.qc_issue		= ata_qc_issue_prot,
+	.qc_transport		= ata_qc_transport,
 	.eng_timeout		= ata_eng_timeout,
 	.irq_handler		= vsc_sata_interrupt,
 	.irq_clear		= ata_bmdma_irq_clear,

Re: [RFC 0/2] libata: support SATA devices on SAS HBAs

[Jeff Garzik]

Bartlomiej Zolnierkiewicz wrote:
> [PATCH] libata: add ops->qc_transport for SAS
> 
> * add ->qc_transport to struct ata_port_operations
> * add default ata_qc_transport() and update all host drivers
> 
> Thanks to this change we won't have to depend on host_set
> and host_set->lock for devices attached to SAS HBAs.
> 
> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>


Seems sane at a quick glance, though I'm a bit disappointed we have to 
add yet another level of indirection to the hot path.

You made a good point, though, by pointing out that all the ata_qc_xxx 
stuff is essentially completely inside a single lock domain.

Other notes:  There may be other dependencies such as wanting to 
reference the struct device pointer in host_set and similar details that 
need handling.  Also, I was planning to move some of the ata_port_ops 
into a separate host_set ops, since they (hooks such as ->irq_clear or 
->host_stop) are really host-wide hooks, not per-port hooks.

	Jeff

[PATCH 0/2] libata: support SATA devices on SAS HBAs

[Brian King]

The following patches enhance libata to allow SAS device drivers
to utilize libata to talk to SATA devices. It introduces some
new APIs which allow libata to be used without allocating a
virtual scsi host. In the context of SAS, a struct ata_port
is not a physical port, but rather becomes a virtual construct.

Since my last post, I have removed the dependence on the host_set
struct. The following two patches depend on the qc_transport patch:

http://marc.theaimsgroup.com/?l=linux-ide&m=112845939215286&w=2

The API is the same as the last time I posted it to linux-ide,
but here is the description again:

New APIs:

ata_sas_port_alloc - Allocate an ata_port 
ata_sas_port_init - Initialize an ata_port (probe device, etc)
ata_sas_port_destroy - Free an ata_port allocated by ata_sas_port_alloc
ata_sas_slave_configure - configure scsi device
ata_sas_queuecmd - queue a scsi command, similar to ata_scsi_queuecomand

These new APIs can be used either directly by a SAS LLDD or could be used
by the SAS transport class. 

Possible usage for a SAS LLDD would be:

scsi_scan_host
	slave_alloc
		ata_sas_port_alloc
		ata_sas_port_init
	slave_configure
		ata_sas_slave_configure

Commands received by the LLDD for SATA devices would call ata_sas_queuecmd.

Device teardown would occur with:

slave_destroy
	ata_sas_port_destroy



-- 
Brian King
eServer Storage I/O
IBM Linux Technology Center

[PATCH 2/2] libata: Add support for SATA attachment to SAS adapters

[Brian King]

[-- Attachment #1: Type: text/plain, Size: 0 bytes --]



[-- Attachment #2: libata_sas.patch --]
[-- Type: text/plain, Size: 11795 bytes --]


The following patch enhances libata to allow SAS device drivers
to utilize libata to talk to SATA devices. It introduces some
new APIs which allow libata to be used without allocating a
virtual scsi host.

Since the last time I posted this code, I have removed all
dependence on the ata_host_set struct.

New APIs:

ata_sas_port_alloc - Allocate an ata_port 
ata_sas_port_init - Initialize an ata_port (probe device, etc)
ata_sas_port_destroy - Free an ata_port allocated by ata_sas_port_alloc
ata_sas_slave_configure - configure scsi device
ata_sas_queuecmd - queue a scsi command, similar to ata_scsi_queuecomand

These new APIs can be used either directly by a SAS LLDD or could be used
by the SAS transport class. 

Possible usage for a SAS LLDD would be:

scsi_scan_host
	slave_alloc
		ata_sas_port_alloc
		ata_sas_port_init
	slave_configure
		ata_sas_slave_configure

Commands received by the LLDD for SATA devices would call ata_sas_queuecmd.

Device teardown would occur with:

slave_destroy
	ata_sas_port_destroy

Signed-off-by: Brian King <brking@us.ibm.com>
---

 linux-2.6-bjking1/drivers/scsi/libata-core.c |   32 ++--
 linux-2.6-bjking1/drivers/scsi/libata-scsi.c |  191 +++++++++++++++++++++++----
 linux-2.6-bjking1/drivers/scsi/libata.h      |    7 
 linux-2.6-bjking1/include/linux/libata.h     |    7 
 4 files changed, 199 insertions(+), 38 deletions(-)

diff -puN drivers/scsi/libata-scsi.c~libata_sas drivers/scsi/libata-scsi.c
--- linux-2.6/drivers/scsi/libata-scsi.c~libata_sas	2005-10-24 15:08:27.000000000 -0500
+++ linux-2.6-bjking1/drivers/scsi/libata-scsi.c	2005-10-24 16:53:48.000000000 -0500
@@ -325,6 +325,30 @@ void ata_to_sense_error(struct ata_queue
 	}
 }
 
+static void ata_scsi_sdev_config(struct scsi_device *sdev)
+{
+	sdev->use_10_for_rw = 1;
+	sdev->use_10_for_ms = 1;
+}
+
+static void ata_scsi_dev_config(struct scsi_device *sdev,
+				struct ata_device *dev)
+{
+	/* TODO: 1024 is an arbitrary number, not the
+	 * hardware maximum.  This should be increased to
+	 * 65534 when Jens Axboe's patch for dynamically
+	 * determining max_sectors is merged.
+	 */
+	if ((dev->flags & ATA_DFLAG_LBA48) &&
+	    ((dev->flags & ATA_DFLAG_LOCK_SECTORS) == 0)) {
+		/*
+		 * do not overwrite sdev->host->max_sectors, since
+		 * other drives on this host may not support LBA48
+		 */
+		blk_queue_max_sectors(sdev->request_queue, 2048);
+	}
+}
+
 /**
  *	ata_scsi_slave_config - Set SCSI device attributes
  *	@sdev: SCSI device to examine
@@ -339,9 +363,7 @@ void ata_to_sense_error(struct ata_queue
 
 int ata_scsi_slave_config(struct scsi_device *sdev)
 {
-	sdev->use_10_for_rw = 1;
-	sdev->use_10_for_ms = 1;
-
+	ata_scsi_sdev_config(sdev);
 	blk_queue_max_phys_segments(sdev->request_queue, LIBATA_MAX_PRD);
 
 	if (sdev->id < ATA_MAX_DEVICES) {
@@ -351,19 +373,7 @@ int ata_scsi_slave_config(struct scsi_de
 		ap = (struct ata_port *) &sdev->host->hostdata[0];
 		dev = &ap->device[sdev->id];
 
-		/* TODO: 1024 is an arbitrary number, not the
-		 * hardware maximum.  This should be increased to
-		 * 65534 when Jens Axboe's patch for dynamically
-		 * determining max_sectors is merged.
-		 */
-		if ((dev->flags & ATA_DFLAG_LBA48) &&
-		    ((dev->flags & ATA_DFLAG_LOCK_SECTORS) == 0)) {
-			/*
-			 * do not overwrite sdev->host->max_sectors, since
-			 * other drives on this host may not support LBA48
-			 */
-			blk_queue_max_sectors(sdev->request_queue, 2048);
-		}
+		ata_scsi_dev_config(sdev, dev);
 	}
 
 	return 0;	/* scsi layer doesn't check return value, sigh */
@@ -1541,6 +1551,21 @@ static inline void ata_scsi_dump_cdb(str
 #endif
 }
 
+static void __ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
+				struct ata_port *ap, struct ata_device *dev)
+{
+	if (dev->class == ATA_DEV_ATA) {
+		ata_xlat_func_t xlat_func = ata_get_xlat_func(dev,
+							      cmd->cmnd[0]);
+
+		if (xlat_func)
+			ata_scsi_translate(ap, dev, cmd, done, xlat_func);
+		else
+			ata_scsi_simulate(dev->id, cmd, done);
+	} else
+		ata_scsi_translate(ap, dev, cmd, done, atapi_xlat);
+}
+
 /**
  *	ata_scsi_queuecmd - Issue SCSI cdb to libata-managed device
  *	@cmd: SCSI command to be sent
@@ -1577,16 +1602,7 @@ int ata_scsi_queuecmd(struct scsi_cmnd *
 		goto out_unlock;
 	}
 
-	if (dev->class == ATA_DEV_ATA) {
-		ata_xlat_func_t xlat_func = ata_get_xlat_func(dev,
-							      cmd->cmnd[0]);
-
-		if (xlat_func)
-			ata_scsi_translate(ap, dev, cmd, done, xlat_func);
-		else
-			ata_scsi_simulate(dev->id, cmd, done);
-	} else
-		ata_scsi_translate(ap, dev, cmd, done, atapi_xlat);
+	__ata_scsi_queuecmd(cmd, done, ap, dev);
 
 out_unlock:
 	return 0;
@@ -1678,3 +1694,126 @@ void ata_scsi_simulate(u16 *id,
 	}
 }
 
+/**
+ *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
+ *	@pdev: PCI device that the scsi device is attached to
+ *	@port_info: Information from low-level host driver
+ *
+ *	LOCKING:
+ *	PCI/etc. bus probe sem.
+ *
+ *	RETURNS:
+ *	ata_port pointer on success / NULL on failure.
+ */
+
+struct ata_port *ata_sas_port_alloc(struct pci_dev *pdev,
+				    struct ata_port_info *port_info)
+{
+	struct ata_port *ap = kzalloc(sizeof(*ap), GFP_KERNEL);
+
+	if (!ap)
+		return NULL;
+
+	ap->dev = &pdev->dev;
+	ap->ops = port_info->port_ops;
+	ap->flags = port_info->host_flags;
+	ap->pio_mask = port_info->pio_mask;
+	ap->mwdma_mask = port_info->mwdma_mask;
+	ap->udma_mask = port_info->udma_mask;
+	ap->cbl = ATA_CBL_SATA;
+	ap->active_tag = ATA_TAG_POISON;
+	ap->last_ctl = 0xFF;
+	return ap;
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
+
+static void ata_sas_port_free(struct ata_port *ap)
+{
+	kfree(ap);
+}
+
+/**
+ *	ata_sas_port_init - Initialize a SATA device
+ *	@ap: SATA port to initialize
+ *
+ *	LOCKING:
+ *	PCI/etc. bus probe sem.
+ *
+ *	RETURNS:
+ *	Zero on success, non-zero on error.
+ */
+
+int ata_sas_port_init(struct ata_port *ap)
+{
+	int rc = ap->ops->port_start(ap);
+
+	if (!rc)
+		rc = ata_bus_probe(ap);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_init);
+
+/**
+ *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
+ *	@ap: SATA port to destroy
+ *
+ */
+
+void ata_sas_port_destroy(struct ata_port *ap)
+{
+	if (ap) {
+		ap->ops->port_stop(ap);
+		ata_sas_port_free(ap);
+	}
+}
+EXPORT_SYMBOL_GPL(ata_sas_port_destroy);
+
+/**
+ *	ata_sas_slave_configure - Default slave_config routine for libata devices
+ *	@sdev: SCSI device to configure
+ *	@ap: ATA port to which SCSI device is attached
+ *
+ *	RETURNS:
+ *	Zero.
+ */
+
+int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
+{
+	ata_scsi_sdev_config(sdev);
+	ata_scsi_dev_config(sdev, ap->device);
+	if (ata_dev_knobble(ap))
+		blk_queue_max_sectors(sdev->request_queue, ATA_MAX_SECTORS);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ata_sas_slave_configure);
+
+/**
+ *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
+ *	@cmd: SCSI command to be sent
+ *	@done: Completion function, called when command is complete
+ *	@ap:	ATA port to which the command is being sent
+ *
+ *	RETURNS:
+ *	Zero.
+ */
+
+int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
+		     struct ata_port *ap)
+{
+	if (unlikely(!ata_dev_present(ap->device))) {
+		cmd->result = (DID_BAD_TARGET << 16);
+		done(cmd);
+		return 0;
+	}
+
+	if (cmd->cmd_len > ap->cdb_len) {
+		cmd->result = (DID_ABORT << 16);
+		done(cmd);
+		return 0;
+	}
+
+	__ata_scsi_queuecmd(cmd, done, ap, ap->device);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
diff -puN drivers/scsi/libata-core.c~libata_sas drivers/scsi/libata-core.c
--- linux-2.6/drivers/scsi/libata-core.c~libata_sas	2005-10-24 15:08:27.000000000 -0500
+++ linux-2.6-bjking1/drivers/scsi/libata-core.c	2005-10-24 15:08:27.000000000 -0500
@@ -1106,6 +1106,21 @@ static inline void ata_dump_id(struct at
 		dev->id[93]);
 }
 
+static void ata_set_cdb_len(struct ata_port *ap, unsigned int cdb_len)
+{
+	ap->cdb_len = cdb_len;
+	if (ap->host)
+		ap->host->max_cmd_len = cdb_len;
+}
+
+static void ata_set_max_sectors(struct ata_port *ap, unsigned int max_sectors)
+{
+	if (ap->host) {
+		ap->host->max_sectors = ATA_MAX_SECTORS;
+		ap->host->hostt->max_sectors = ATA_MAX_SECTORS;
+	}
+}
+
 /**
  *	ata_dev_identify - obtain IDENTIFY x DEVICE page
  *	@ap: port on which device we wish to probe resides
@@ -1266,7 +1281,7 @@ retry:
 			dev->n_sectors = ata_id_u32(dev->id, 60);
 		}
 
-		ap->host->max_cmd_len = 16;
+		ata_set_cdb_len(ap, 16);
 
 		/* print device info to dmesg */
 		printk(KERN_INFO "ata%u: dev %u ATA, max %s, %Lu sectors:%s\n",
@@ -1286,8 +1301,8 @@ retry:
 			printk(KERN_WARNING "ata%u: unsupported CDB len\n", ap->id);
 			goto err_out_nosup;
 		}
-		ap->cdb_len = (unsigned int) rc;
-		ap->host->max_cmd_len = (unsigned char) ap->cdb_len;
+
+		ata_set_cdb_len(ap, rc);
 
 		/* print device info to dmesg */
 		printk(KERN_INFO "ata%u: dev %u ATAPI, max %s\n",
@@ -1306,12 +1321,6 @@ err_out:
 	DPRINTK("EXIT, err\n");
 }
 
-
-static inline u8 ata_dev_knobble(struct ata_port *ap)
-{
-	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(ap->device->id)));
-}
-
 /**
  * 	ata_dev_config - Run device specific handlers and check for
  * 			 SATA->PATA bridges
@@ -1328,8 +1337,7 @@ void ata_dev_config(struct ata_port *ap,
 		printk(KERN_INFO "ata%u(%u): applying bridge limits\n",
 			ap->id, ap->device->devno);
 		ap->udma_mask &= ATA_UDMA5;
-		ap->host->max_sectors = ATA_MAX_SECTORS;
-		ap->host->hostt->max_sectors = ATA_MAX_SECTORS;
+		ata_set_max_sectors(ap, ATA_MAX_SECTORS);
 		ap->device->flags |= ATA_DFLAG_LOCK_SECTORS;
 	}
 
@@ -1352,7 +1360,7 @@ void ata_dev_config(struct ata_port *ap,
  *	Zero on success, non-zero on error.
  */
 
-static int ata_bus_probe(struct ata_port *ap)
+int ata_bus_probe(struct ata_port *ap)
 {
 	unsigned int i, found = 0;
 
diff -puN drivers/scsi/libata.h~libata_sas drivers/scsi/libata.h
--- linux-2.6/drivers/scsi/libata.h~libata_sas	2005-10-24 15:08:27.000000000 -0500
+++ linux-2.6-bjking1/drivers/scsi/libata.h	2005-10-24 15:08:27.000000000 -0500
@@ -79,6 +79,8 @@ extern void ata_scsi_badcmd(struct scsi_
 extern void ata_scsi_rbuf_fill(struct ata_scsi_args *args,
                         unsigned int (*actor) (struct ata_scsi_args *args,
                                            u8 *rbuf, unsigned int buflen));
+extern int ata_bus_probe(struct ata_port *ap);
+extern int ata_sas_port_init(struct ata_port *ap);
 
 static inline void ata_bad_scsiop(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
 {
@@ -90,4 +92,9 @@ static inline void ata_bad_cdb(struct sc
 	ata_scsi_badcmd(cmd, done, 0x24, 0x00);
 }
 
+static inline u8 ata_dev_knobble(struct ata_port *ap)
+{
+	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(ap->device->id)));
+}
+
 #endif /* __LIBATA_H__ */
diff -puN include/linux/libata.h~libata_sas include/linux/libata.h
--- linux-2.6/include/linux/libata.h~libata_sas	2005-10-24 15:08:27.000000000 -0500
+++ linux-2.6-bjking1/include/linux/libata.h	2005-10-24 15:08:27.000000000 -0500
@@ -401,6 +401,13 @@ extern int ata_scsi_ioctl(struct scsi_de
 extern int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *));
 extern int ata_scsi_error(struct Scsi_Host *host);
 extern int ata_scsi_release(struct Scsi_Host *host);
+extern void ata_sas_port_destroy(struct ata_port *ap);
+extern struct ata_port *ata_sas_port_alloc(struct pci_dev *pdev,
+					   struct ata_port_info *port_info);
+extern int ata_sas_port_init(struct ata_port *ap);
+extern int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap);
+extern int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
+			    struct ata_port *ap);
 extern unsigned int ata_host_intr(struct ata_port *ap, struct ata_queued_cmd *qc);
 /*
  * Default driver ops implementations
_

Re: [PATCH 2/2] libata: Add support for SATA attachment to SAS adapters

[Jeff Garzik]

Brian King wrote:
> +/**
> + *	ata_sas_port_alloc - Allocate port for a SAS attached SATA device
> + *	@pdev: PCI device that the scsi device is attached to
> + *	@port_info: Information from low-level host driver
> + *
> + *	LOCKING:
> + *	PCI/etc. bus probe sem.
> + *
> + *	RETURNS:
> + *	ata_port pointer on success / NULL on failure.
> + */
> +
> +struct ata_port *ata_sas_port_alloc(struct pci_dev *pdev,
> +				    struct ata_port_info *port_info)
> +{
> +	struct ata_port *ap = kzalloc(sizeof(*ap), GFP_KERNEL);
> +
> +	if (!ap)
> +		return NULL;
> +
> +	ap->dev = &pdev->dev;
> +	ap->ops = port_info->port_ops;
> +	ap->flags = port_info->host_flags;
> +	ap->pio_mask = port_info->pio_mask;
> +	ap->mwdma_mask = port_info->mwdma_mask;
> +	ap->udma_mask = port_info->udma_mask;
> +	ap->cbl = ATA_CBL_SATA;
> +	ap->active_tag = ATA_TAG_POISON;
> +	ap->last_ctl = 0xFF;
> +	return ap;
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_port_alloc);
> +
> +static void ata_sas_port_free(struct ata_port *ap)
> +{
> +	kfree(ap);
> +}
> +
> +/**
> + *	ata_sas_port_init - Initialize a SATA device
> + *	@ap: SATA port to initialize
> + *
> + *	LOCKING:
> + *	PCI/etc. bus probe sem.
> + *
> + *	RETURNS:
> + *	Zero on success, non-zero on error.
> + */
> +
> +int ata_sas_port_init(struct ata_port *ap)
> +{
> +	int rc = ap->ops->port_start(ap);
> +
> +	if (!rc)
> +		rc = ata_bus_probe(ap);
> +
> +	return rc;
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_port_init);
> +
> +/**
> + *	ata_sas_port_destroy - Destroy a SATA port allocated by ata_sas_port_alloc
> + *	@ap: SATA port to destroy
> + *
> + */
> +
> +void ata_sas_port_destroy(struct ata_port *ap)
> +{
> +	if (ap) {
> +		ap->ops->port_stop(ap);
> +		ata_sas_port_free(ap);
> +	}
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_port_destroy);
> +
> +/**
> + *	ata_sas_slave_configure - Default slave_config routine for libata devices
> + *	@sdev: SCSI device to configure
> + *	@ap: ATA port to which SCSI device is attached
> + *
> + *	RETURNS:
> + *	Zero.
> + */
> +
> +int ata_sas_slave_configure(struct scsi_device *sdev, struct ata_port *ap)
> +{
> +	ata_scsi_sdev_config(sdev);
> +	ata_scsi_dev_config(sdev, ap->device);
> +	if (ata_dev_knobble(ap))
> +		blk_queue_max_sectors(sdev->request_queue, ATA_MAX_SECTORS);
> +	return 0;
> +}
> +EXPORT_SYMBOL_GPL(ata_sas_slave_configure);
> +
> +/**
> + *	ata_sas_queuecmd - Issue SCSI cdb to libata-managed device
> + *	@cmd: SCSI command to be sent
> + *	@done: Completion function, called when command is complete
> + *	@ap:	ATA port to which the command is being sent
> + *
> + *	RETURNS:
> + *	Zero.
> + */
> +
> +int ata_sas_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *),
> +		     struct ata_port *ap)
> +{
> +	if (unlikely(!ata_dev_present(ap->device))) {
> +		cmd->result = (DID_BAD_TARGET << 16);
> +		done(cmd);
> +		return 0;
> +	}
> +
> +	if (cmd->cmd_len > ap->cdb_len) {
> +		cmd->result = (DID_ABORT << 16);
> +		done(cmd);
> +		return 0;
> +	}
> +
> +	__ata_scsi_queuecmd(cmd, done, ap, ap->device);
> +	return 0;
> +}

I'm still thinking about these functions, so it would be nice to split 
them up into a third patch.  That would allow me to apply the other 
cleanups in this patch.

	Jeff