This is a follow-up to the series at [0] to fix SCSI device tagging and
use the per-device token as the libata qc tag.
I added the changes Christoph shared on the list to move
the functionality from ata_qc_new_init() into libata-scsi.c
Please do not apply on a kernel which does not include
"scsi: core: Fix sbitmap depth in scsi_realloc_sdev_budget_map()"
v5.18-rc2 should be the release to include that patch.
[0] https://lore.kernel.org/linux-ide/[email protected]/
Christoph Hellwig (1):
libata: Inline ata_qc_new_init() in ata_scsi_qc_new()
John Garry (1):
libata: Use scsi cmnd budget token for qc tag for SAS host
Documentation/driver-api/libata.rst | 11 -------
drivers/ata/libata-core.c | 48 +----------------------------
drivers/ata/libata-sata.c | 25 ---------------
drivers/ata/libata-scsi.c | 45 ++++++++++++++++++++-------
drivers/ata/libata.h | 13 --------
include/linux/libata.h | 1 -
6 files changed, 35 insertions(+), 108 deletions(-)
--
2.26.2
For attaining a qc tag for a SAS host we need to allocate a bit in
ata_port.sas_tag_allocated bitmap.
However we already have a unique tag per device in range
[0, ATA_MAX_QUEUE) in the scsi cmnd budget token, so just use that
instead.
Signed-off-by: John Garry <[email protected]>
---
drivers/ata/libata-core.c | 14 +++++---------
drivers/ata/libata-sata.c | 25 ++++---------------------
drivers/ata/libata-scsi.c | 2 +-
drivers/ata/libata.h | 7 +++----
include/linux/libata.h | 1 -
5 files changed, 13 insertions(+), 36 deletions(-)
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index cceedde51126..1067b2e2be28 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4566,14 +4566,15 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
/**
* ata_qc_new_init - Request an available ATA command, and initialize it
* @dev: Device from whom we request an available command structure
- * @tag: tag
+ * @scmd: scmd for which to get qc
*
* LOCKING:
* None.
*/
-struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
+struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, struct scsi_cmnd *scmd)
{
+ int tag = scsi_cmd_to_rq(scmd)->tag;
struct ata_port *ap = dev->link->ap;
struct ata_queued_cmd *qc;
@@ -4583,7 +4584,7 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
/* libsas case */
if (ap->flags & ATA_FLAG_SAS_HOST) {
- tag = ata_sas_allocate_tag(ap);
+ tag = ata_sas_get_tag(scmd);
if (tag < 0)
return NULL;
}
@@ -4611,19 +4612,14 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
*/
void ata_qc_free(struct ata_queued_cmd *qc)
{
- struct ata_port *ap;
unsigned int tag;
WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
- ap = qc->ap;
qc->flags = 0;
tag = qc->tag;
- if (ata_tag_valid(tag)) {
+ if (ata_tag_valid(tag))
qc->tag = ATA_TAG_POISON;
- if (ap->flags & ATA_FLAG_SAS_HOST)
- ata_sas_free_tag(tag, ap);
- }
}
void __ata_qc_complete(struct ata_queued_cmd *qc)
diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
index 044a16daa2d4..c3e9fd7d920c 100644
--- a/drivers/ata/libata-sata.c
+++ b/drivers/ata/libata-sata.c
@@ -1268,29 +1268,12 @@ int ata_sas_queuecmd(struct scsi_cmnd *cmd, struct ata_port *ap)
}
EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
-int ata_sas_allocate_tag(struct ata_port *ap)
+int ata_sas_get_tag(struct scsi_cmnd *scmd)
{
- unsigned int max_queue = ap->host->n_tags;
- unsigned int i, tag;
+ if (WARN_ON_ONCE(scmd->budget_token >= ATA_MAX_QUEUE))
+ return -1;
- for (i = 0, tag = ap->sas_last_tag + 1; i < max_queue; i++, tag++) {
- tag = tag < max_queue ? tag : 0;
-
- /* the last tag is reserved for internal command. */
- if (ata_tag_internal(tag))
- continue;
-
- if (!test_and_set_bit(tag, &ap->sas_tag_allocated)) {
- ap->sas_last_tag = tag;
- return tag;
- }
- }
- return -1;
-}
-
-void ata_sas_free_tag(unsigned int tag, struct ata_port *ap)
-{
- clear_bit(tag, &ap->sas_tag_allocated);
+ return scmd->budget_token;
}
/**
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 06c9d90238d9..61dd7f7c7743 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -640,7 +640,7 @@ static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev,
{
struct ata_queued_cmd *qc;
- qc = ata_qc_new_init(dev, scsi_cmd_to_rq(cmd)->tag);
+ qc = ata_qc_new_init(dev, cmd);
if (qc) {
qc->scsicmd = cmd;
qc->scsidone = scsi_done;
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index c9c2496d91ea..92e52090165b 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -44,7 +44,7 @@ static inline void ata_force_cbl(struct ata_port *ap) { }
#endif
extern u64 ata_tf_to_lba(const struct ata_taskfile *tf);
extern u64 ata_tf_to_lba48(const struct ata_taskfile *tf);
-extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag);
+extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, struct scsi_cmnd *scmd);
extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
u64 block, u32 n_block, unsigned int tf_flags,
unsigned int tag, int class);
@@ -93,10 +93,9 @@ extern unsigned int ata_read_log_page(struct ata_device *dev, u8 log,
/* libata-sata.c */
#ifdef CONFIG_SATA_HOST
-int ata_sas_allocate_tag(struct ata_port *ap);
-void ata_sas_free_tag(unsigned int tag, struct ata_port *ap);
+int ata_sas_get_tag(struct scsi_cmnd *scmd);
#else
-static inline int ata_sas_allocate_tag(struct ata_port *ap)
+static inline int ata_sas_get_tag(struct scsi_cmnd *scmd)
{
return -EOPNOTSUPP;
}
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 9b1d3d8b1252..16107122e587 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -820,7 +820,6 @@ struct ata_port {
unsigned int cbl; /* cable type; ATA_CBL_xxx */
struct ata_queued_cmd qcmd[ATA_MAX_QUEUE + 1];
- unsigned long sas_tag_allocated; /* for sas tag allocation only */
u64 qc_active;
int nr_active_links; /* #links with active qcs */
unsigned int sas_last_tag; /* track next tag hw expects */
--
2.26.2
On 4/4/22 23:53, John Garry wrote:
> For attaining a qc tag for a SAS host we need to allocate a bit in
> ata_port.sas_tag_allocated bitmap.
>
> However we already have a unique tag per device in range
> [0, ATA_MAX_QUEUE) in the scsi cmnd budget token, so just use that
> instead.
The valid range is [0, ATA_MAX_QUEUE - 1]. Tag ATA_MAX_QUEUE is
ATA_TAG_INTERNAL which is never allocated as a valid device tag but used
directly in ata_exec_internal().
>
> Signed-off-by: John Garry <[email protected]>
> ---
> drivers/ata/libata-core.c | 14 +++++---------
> drivers/ata/libata-sata.c | 25 ++++---------------------
> drivers/ata/libata-scsi.c | 2 +-
> drivers/ata/libata.h | 7 +++----
> include/linux/libata.h | 1 -
> 5 files changed, 13 insertions(+), 36 deletions(-)
>
> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
> index cceedde51126..1067b2e2be28 100644
> --- a/drivers/ata/libata-core.c
> +++ b/drivers/ata/libata-core.c
> @@ -4566,14 +4566,15 @@ void swap_buf_le16(u16 *buf, unsigned int buf_words)
> /**
> * ata_qc_new_init - Request an available ATA command, and initialize it
> * @dev: Device from whom we request an available command structure
> - * @tag: tag
> + * @scmd: scmd for which to get qc
> *
> * LOCKING:
> * None.
> */
>
> -struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
> +struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, struct scsi_cmnd *scmd)
> {
> + int tag = scsi_cmd_to_rq(scmd)->tag;
> struct ata_port *ap = dev->link->ap;
> struct ata_queued_cmd *qc;
>
> @@ -4583,7 +4584,7 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
>
> /* libsas case */
> if (ap->flags & ATA_FLAG_SAS_HOST) {
> - tag = ata_sas_allocate_tag(ap);
> + tag = ata_sas_get_tag(scmd);
> if (tag < 0)
> return NULL;
> }
> @@ -4611,19 +4612,14 @@ struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
> */
> void ata_qc_free(struct ata_queued_cmd *qc)
> {
> - struct ata_port *ap;
> unsigned int tag;
>
> WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
> - ap = qc->ap;
>
> qc->flags = 0;
> tag = qc->tag;
> - if (ata_tag_valid(tag)) {
> + if (ata_tag_valid(tag))
> qc->tag = ATA_TAG_POISON;
> - if (ap->flags & ATA_FLAG_SAS_HOST)
> - ata_sas_free_tag(tag, ap);
> - }
> }
>
> void __ata_qc_complete(struct ata_queued_cmd *qc)
> diff --git a/drivers/ata/libata-sata.c b/drivers/ata/libata-sata.c
> index 044a16daa2d4..c3e9fd7d920c 100644
> --- a/drivers/ata/libata-sata.c
> +++ b/drivers/ata/libata-sata.c
> @@ -1268,29 +1268,12 @@ int ata_sas_queuecmd(struct scsi_cmnd *cmd, struct ata_port *ap)
> }
> EXPORT_SYMBOL_GPL(ata_sas_queuecmd);
>
> -int ata_sas_allocate_tag(struct ata_port *ap)
> +int ata_sas_get_tag(struct scsi_cmnd *scmd)
> {
> - unsigned int max_queue = ap->host->n_tags;
> - unsigned int i, tag;
> + if (WARN_ON_ONCE(scmd->budget_token >= ATA_MAX_QUEUE))
> + return -1;
>
> - for (i = 0, tag = ap->sas_last_tag + 1; i < max_queue; i++, tag++) {
> - tag = tag < max_queue ? tag : 0;
> -
> - /* the last tag is reserved for internal command. */
> - if (ata_tag_internal(tag))
> - continue;
> -
> - if (!test_and_set_bit(tag, &ap->sas_tag_allocated)) {
> - ap->sas_last_tag = tag;
> - return tag;
> - }
> - }
> - return -1;
> -}
> -
> -void ata_sas_free_tag(unsigned int tag, struct ata_port *ap)
> -{
> - clear_bit(tag, &ap->sas_tag_allocated);
> + return scmd->budget_token;
> }
>
> /**
> diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
> index 06c9d90238d9..61dd7f7c7743 100644
> --- a/drivers/ata/libata-scsi.c
> +++ b/drivers/ata/libata-scsi.c
> @@ -640,7 +640,7 @@ static struct ata_queued_cmd *ata_scsi_qc_new(struct ata_device *dev,
> {
> struct ata_queued_cmd *qc;
>
> - qc = ata_qc_new_init(dev, scsi_cmd_to_rq(cmd)->tag);
> + qc = ata_qc_new_init(dev, cmd);
> if (qc) {
> qc->scsicmd = cmd;
> qc->scsidone = scsi_done;
> diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
> index c9c2496d91ea..92e52090165b 100644
> --- a/drivers/ata/libata.h
> +++ b/drivers/ata/libata.h
> @@ -44,7 +44,7 @@ static inline void ata_force_cbl(struct ata_port *ap) { }
> #endif
> extern u64 ata_tf_to_lba(const struct ata_taskfile *tf);
> extern u64 ata_tf_to_lba48(const struct ata_taskfile *tf);
> -extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag);
> +extern struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, struct scsi_cmnd *scmd);
> extern int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
> u64 block, u32 n_block, unsigned int tf_flags,
> unsigned int tag, int class);
> @@ -93,10 +93,9 @@ extern unsigned int ata_read_log_page(struct ata_device *dev, u8 log,
>
> /* libata-sata.c */
> #ifdef CONFIG_SATA_HOST
> -int ata_sas_allocate_tag(struct ata_port *ap);
> -void ata_sas_free_tag(unsigned int tag, struct ata_port *ap);
> +int ata_sas_get_tag(struct scsi_cmnd *scmd);
> #else
> -static inline int ata_sas_allocate_tag(struct ata_port *ap)
> +static inline int ata_sas_get_tag(struct scsi_cmnd *scmd)
> {
> return -EOPNOTSUPP;
> }
> diff --git a/include/linux/libata.h b/include/linux/libata.h
> index 9b1d3d8b1252..16107122e587 100644
> --- a/include/linux/libata.h
> +++ b/include/linux/libata.h
> @@ -820,7 +820,6 @@ struct ata_port {
> unsigned int cbl; /* cable type; ATA_CBL_xxx */
>
> struct ata_queued_cmd qcmd[ATA_MAX_QUEUE + 1];
> - unsigned long sas_tag_allocated; /* for sas tag allocation only */
> u64 qc_active;
> int nr_active_links; /* #links with active qcs */
> unsigned int sas_last_tag; /* track next tag hw expects */
--
Damien Le Moal
Western Digital Research
On 06/04/2022 02:39, Damien Le Moal wrote:
> On 4/4/22 23:53, John Garry wrote:
>> For attaining a qc tag for a SAS host we need to allocate a bit in
>> ata_port.sas_tag_allocated bitmap.
>>
>> However we already have a unique tag per device in range
>> [0, ATA_MAX_QUEUE) in the scsi cmnd budget token, so just use that
>> instead.
>
> The valid range is [0, ATA_MAX_QUEUE - 1]. Tag ATA_MAX_QUEUE is
> ATA_TAG_INTERNAL which is never allocated as a valid device tag but used
> directly in ata_exec_internal().
But that is what I have in [0, ATA_MAX_QUEUE), which is same as [0,
ATA_MAX_QUEUE - 1].
Thanks,
john
On 4/6/22 16:12, John Garry wrote:
> On 06/04/2022 02:39, Damien Le Moal wrote:
>> On 4/4/22 23:53, John Garry wrote:
>>> For attaining a qc tag for a SAS host we need to allocate a bit in
>>> ata_port.sas_tag_allocated bitmap.
>>>
>>> However we already have a unique tag per device in range
>>> [0, ATA_MAX_QUEUE) in the scsi cmnd budget token, so just use that
>>> instead.
>>
>> The valid range is [0, ATA_MAX_QUEUE - 1]. Tag ATA_MAX_QUEUE is
>> ATA_TAG_INTERNAL which is never allocated as a valid device tag but
>> used directly in ata_exec_internal().
>
> But that is what I have in [0, ATA_MAX_QUEUE), which is same as [0,
> ATA_MAX_QUEUE - 1].
Oh ! I missed the ")" !
I would prefer an explicit [0, ATA_MAX_QUEUE - 1] to be clear :)
>
> Thanks,
> john
--
Damien Le Moal
Western Digital Research