LinuxLists.cc - [PATCH v2 0/6] scsi: libsas: Use request tag in more drivers

[permalink] [raw]

Subject: [PATCH v2 3/6] scsi: pm8001: Remove pm8001_tag_init()

From: Igor Pylypiv <[email protected]>

In commit 5a141315ed7c ("scsi: pm80xx: Increase the number of outstanding
I/O supported to 1024") the pm8001_ha->tags allocation was moved into
pm8001_init_ccb_tag(). This changed the execution order of allocation.
pm8001_tag_init() used to be called after the pm8001_ha->tags allocation
and now it is called before the allocation.

Before:

pm8001_pci_probe()
`--> pm8001_pci_alloc()
`--> pm8001_alloc()
`--> pm8001_ha->tags = kzalloc(...)
`--> pm8001_tag_init(pm8001_ha); // OK: tags are allocated

After:

pm8001_pci_probe()
`--> pm8001_pci_alloc()
| `--> pm8001_alloc()
| `--> pm8001_tag_init(pm8001_ha); // NOK: tags are not allocated
|
`--> pm8001_init_ccb_tag()
`--> pm8001_ha->tags = kzalloc(...) // today it is bitmap_zalloc()

Since pm8001_ha->tags_num is zero when pm8001_tag_init() is called it does
nothing. Tags memory is allocated with bitmap_zalloc() so there is no need
to manually clear each bit with pm8001_tag_free().

Reviewed-by: Changyuan Lyu <[email protected]>
Signed-off-by: Igor Pylypiv <[email protected]>
Signed-off-by: John Garry <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
---
drivers/scsi/pm8001/pm8001_init.c | 2 --
drivers/scsi/pm8001/pm8001_sas.c | 7 -------
drivers/scsi/pm8001/pm8001_sas.h | 1 -
3 files changed, 10 deletions(-)

diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index a0028e130a7e..0edc9857a8bd 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -436,8 +436,6 @@ static int pm8001_alloc(struct pm8001_hba_info *pm8001_ha,
atomic_set(&pm8001_ha->devices[i].running_req, 0);
}
pm8001_ha->flags = PM8001F_INIT_TIME;
- /* Initialize tags */
- pm8001_tag_init(pm8001_ha);
return 0;

err_out_nodev:
diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index d5ec29f69be3..066dfa9f4683 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -96,13 +96,6 @@ int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
return 0;
}

-void pm8001_tag_init(struct pm8001_hba_info *pm8001_ha)
-{
- int i;
- for (i = 0; i < pm8001_ha->tags_num; ++i)
- pm8001_tag_free(pm8001_ha, i);
-}
-
/**
* pm8001_mem_alloc - allocate memory for pm8001.
* @pdev: pci device.
diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
index 8ab0654327f9..9acaadf02150 100644
--- a/drivers/scsi/pm8001/pm8001_sas.h
+++ b/drivers/scsi/pm8001/pm8001_sas.h
@@ -632,7 +632,6 @@ extern struct workqueue_struct *pm8001_wq;

/******************** function prototype *********************/
int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out);
-void pm8001_tag_init(struct pm8001_hba_info *pm8001_ha);
u32 pm8001_get_ncq_tag(struct sas_task *task, u32 *tag);
void pm8001_ccb_task_free(struct pm8001_hba_info *pm8001_ha,
struct pm8001_ccb_info *ccb);
--
2.35.3

2022-09-30 09:10:20

[permalink] [raw]

Subject: [PATCH v2 5/6] scsi: mvsas: Delete mvs_tag_init()

All mvs_tag_init() does is zero the tag bitmap, but this is already done
with the kzalloc() call to alloc the tags, so delete this unneeded
function.

Signed-off-by: John Garry <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
---
drivers/scsi/mvsas/mv_init.c | 2 --
drivers/scsi/mvsas/mv_sas.c | 7 -------
drivers/scsi/mvsas/mv_sas.h | 1 -
3 files changed, 10 deletions(-)

diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c
index 2fde496fff5f..c85fb812ad43 100644
--- a/drivers/scsi/mvsas/mv_init.c
+++ b/drivers/scsi/mvsas/mv_init.c
@@ -286,8 +286,6 @@ static int mvs_alloc(struct mvs_info *mvi, struct Scsi_Host *shost)
}
mvi->tags_num = slot_nr;

- /* Initialize tags */
- mvs_tag_init(mvi);
return 0;
err_out:
return 1;
diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
index a6867dae0e7c..0810e6c930e1 100644
--- a/drivers/scsi/mvsas/mv_sas.c
+++ b/drivers/scsi/mvsas/mv_sas.c
@@ -51,13 +51,6 @@ inline int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out)
return 0;
}

-void mvs_tag_init(struct mvs_info *mvi)
-{
- int i;
- for (i = 0; i < mvi->tags_num; ++i)
- mvs_tag_clear(mvi, i);
-}
-
static struct mvs_info *mvs_find_dev_mvi(struct domain_device *dev)
{
unsigned long i = 0, j = 0, hi = 0;
diff --git a/drivers/scsi/mvsas/mv_sas.h b/drivers/scsi/mvsas/mv_sas.h
index 509d8f32a04f..fe57665bdb50 100644
--- a/drivers/scsi/mvsas/mv_sas.h
+++ b/drivers/scsi/mvsas/mv_sas.h
@@ -428,7 +428,6 @@ void mvs_tag_clear(struct mvs_info *mvi, u32 tag);
void mvs_tag_free(struct mvs_info *mvi, u32 tag);
void mvs_tag_set(struct mvs_info *mvi, unsigned int tag);
int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out);
-void mvs_tag_init(struct mvs_info *mvi);
void mvs_iounmap(void __iomem *regs);
int mvs_ioremap(struct mvs_info *mvi, int bar, int bar_ex);
void mvs_phys_reset(struct mvs_info *mvi, u32 phy_mask, int hard);
--
2.35.3

2022-09-30 09:10:51

[permalink] [raw]

Subject: [PATCH v2 1/6] scsi: libsas: Add sas_task_find_rq()

blk-mq already provides a unique tag per request. Some libsas LLDDs - like
hisi_sas - already use this tag as the unique per-IO HW tag.

Add a common function to provide the request associated with a sas_task
for all libsas LLDDs.

Signed-off-by: John Garry <[email protected]>
---
include/scsi/libsas.h | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)

diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index f86b56bf7833..f498217961db 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -644,6 +644,24 @@ static inline bool sas_is_internal_abort(struct sas_task *task)
return task->task_proto == SAS_PROTOCOL_INTERNAL_ABORT;
}

+static inline struct request *sas_task_find_rq(struct sas_task *task)
+{
+ struct scsi_cmnd *scmd;
+
+ if (task->task_proto & SAS_PROTOCOL_STP_ALL) {
+ struct ata_queued_cmd *qc = task->uldd_task;
+
+ scmd = qc ? qc->scsicmd : NULL;
+ } else {
+ scmd = task->uldd_task;
+ }
+
+ if (!scmd)
+ return NULL;
+
+ return scsi_cmd_to_rq(scmd);
+}
+
struct sas_domain_function_template {
/* The class calls these to notify the LLDD of an event. */
void (*lldd_port_formed)(struct asd_sas_phy *);
--
2.35.3

2022-09-30 09:23:38

[permalink] [raw]

Subject: Re: [PATCH v2 1/6] scsi: libsas: Add sas_task_find_rq()

On Fri, Sep 30, 2022 at 11:03 AM John Garry <[email protected]> wrote:
>
> blk-mq already provides a unique tag per request. Some libsas LLDDs - like
> hisi_sas - already use this tag as the unique per-IO HW tag.
>
> Add a common function to provide the request associated with a sas_task
> for all libsas LLDDs.
>
> Signed-off-by: John Garry <[email protected]>
lgtm
Reviewed-by: Jack Wang <[email protected]>
> ---
> include/scsi/libsas.h | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
> diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
> index f86b56bf7833..f498217961db 100644
> --- a/include/scsi/libsas.h
> +++ b/include/scsi/libsas.h
> @@ -644,6 +644,24 @@ static inline bool sas_is_internal_abort(struct sas_task *task)
> return task->task_proto == SAS_PROTOCOL_INTERNAL_ABORT;
> }
>
> +static inline struct request *sas_task_find_rq(struct sas_task *task)
> +{
> + struct scsi_cmnd *scmd;
> +
> + if (task->task_proto & SAS_PROTOCOL_STP_ALL) {
> + struct ata_queued_cmd *qc = task->uldd_task;
> +
> + scmd = qc ? qc->scsicmd : NULL;
> + } else {
> + scmd = task->uldd_task;
> + }
> +
> + if (!scmd)
> + return NULL;
> +
> + return scsi_cmd_to_rq(scmd);
> +}
> +
> struct sas_domain_function_template {
> /* The class calls these to notify the LLDD of an event. */
> void (*lldd_port_formed)(struct asd_sas_phy *);
> --
> 2.35.3
>

2022-09-30 09:28:16

[permalink] [raw]

Subject: [PATCH v2 4/6] scsi: pm8001: Use sas_task_find_rq() for tagging

The request associated with a scsi command coming from the block layer
has a unique tag, so use that when possible for getting a CCB.

Unfortunately we don't support reserved commands in the SCSI midlayer yet,
so in the interim continue to manage those tags internally (along with
tags for private commands).

Signed-off-by: John Garry <[email protected]>
---
drivers/scsi/pm8001/pm8001_init.c | 12 ++++--------
drivers/scsi/pm8001/pm8001_sas.c | 16 ++++++++++++----
drivers/scsi/pm8001/pm8001_sas.h | 11 ++++++++---
drivers/scsi/pm8001/pm80xx_hwi.c | 17 +++--------------
4 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index 0edc9857a8bd..abb884ddcaf9 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -196,7 +196,7 @@ static void pm8001_free(struct pm8001_hba_info *pm8001_ha)
}
PM8001_CHIP_DISP->chip_iounmap(pm8001_ha);
flush_workqueue(pm8001_wq);
- bitmap_free(pm8001_ha->tags);
+ bitmap_free(pm8001_ha->rsvd_tags);
kfree(pm8001_ha);
}

@@ -1208,18 +1208,15 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
struct Scsi_Host *shost = pm8001_ha->shost;
struct device *dev = pm8001_ha->dev;
u32 max_out_io, ccb_count;
- u32 can_queue;
int i;

max_out_io = pm8001_ha->main_cfg_tbl.pm80xx_tbl.max_out_io;
ccb_count = min_t(int, PM8001_MAX_CCB, max_out_io);

- /* Update to the scsi host*/
- can_queue = ccb_count - PM8001_RESERVE_SLOT;
- shost->can_queue = can_queue;
+ shost->can_queue = ccb_count - PM8001_RESERVE_SLOT;

- pm8001_ha->tags = bitmap_zalloc(ccb_count, GFP_KERNEL);
- if (!pm8001_ha->tags)
+ pm8001_ha->rsvd_tags = bitmap_zalloc(PM8001_RESERVE_SLOT, GFP_KERNEL);
+ if (!pm8001_ha->rsvd_tags)
goto err_out;

/* Memory region for ccb_info*/
@@ -1244,7 +1241,6 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
pm8001_ha->ccb_info[i].task = NULL;
pm8001_ha->ccb_info[i].ccb_tag = PM8001_INVALID_TAG;
pm8001_ha->ccb_info[i].device = NULL;
- ++pm8001_ha->tags_num;
}

return 0;
diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index 066dfa9f4683..d60bc311a4e9 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -65,9 +65,14 @@ static int pm8001_find_tag(struct sas_task *task, u32 *tag)
*/
void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
{
- void *bitmap = pm8001_ha->tags;
+ void *bitmap = pm8001_ha->rsvd_tags;
unsigned long flags;

+ if (tag < pm8001_ha->shost->can_queue)
+ return;
+
+ tag -= pm8001_ha->shost->can_queue;
+
spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
__clear_bit(tag, bitmap);
spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
@@ -80,18 +85,21 @@ void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
*/
int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
{
- void *bitmap = pm8001_ha->tags;
+ void *bitmap = pm8001_ha->rsvd_tags;
unsigned long flags;
unsigned int tag;

spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
- tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
- if (tag >= pm8001_ha->tags_num) {
+ tag = find_first_zero_bit(bitmap, PM8001_RESERVE_SLOT);
+ if (tag >= PM8001_RESERVE_SLOT) {
spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
return -SAS_QUEUE_FULL;
}
__set_bit(tag, bitmap);
spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
+
+ /* reserved tags are in the upper region of the tagset */
+ tag += pm8001_ha->shost->can_queue;
*tag_out = tag;
return 0;
}
diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
index 9acaadf02150..ba32b009f412 100644
--- a/drivers/scsi/pm8001/pm8001_sas.h
+++ b/drivers/scsi/pm8001/pm8001_sas.h
@@ -510,8 +510,7 @@ struct pm8001_hba_info {
u32 chip_id;
const struct pm8001_chip_info *chip;
struct completion *nvmd_completion;
- int tags_num;
- unsigned long *tags;
+ unsigned long *rsvd_tags;
struct pm8001_phy phy[PM8001_MAX_PHYS];
struct pm8001_port port[PM8001_MAX_PHYS];
u32 id;
@@ -737,9 +736,15 @@ pm8001_ccb_alloc(struct pm8001_hba_info *pm8001_ha,
struct pm8001_device *dev, struct sas_task *task)
{
struct pm8001_ccb_info *ccb;
+ struct request *rq = NULL;
u32 tag;

- if (pm8001_tag_alloc(pm8001_ha, &tag)) {
+ if (task)
+ rq = sas_task_find_rq(task);
+
+ if (rq) {
+ tag = rq->tag;
+ } else if (pm8001_tag_alloc(pm8001_ha, &tag)) {
pm8001_dbg(pm8001_ha, FAIL, "Failed to allocate a tag\n");
return NULL;
}
diff --git a/drivers/scsi/pm8001/pm80xx_hwi.c b/drivers/scsi/pm8001/pm80xx_hwi.c
index 4484c498bcb6..ed2d65d3749a 100644
--- a/drivers/scsi/pm8001/pm80xx_hwi.c
+++ b/drivers/scsi/pm8001/pm80xx_hwi.c
@@ -4247,24 +4247,13 @@ static int check_enc_sat_cmd(struct sas_task *task)

static u32 pm80xx_chip_get_q_index(struct sas_task *task)
{
- struct scsi_cmnd *scmd = NULL;
+ struct request *rq = sas_task_find_rq(task);
u32 blk_tag;

- if (task->uldd_task) {
- struct ata_queued_cmd *qc;
-
- if (dev_is_sata(task->dev)) {
- qc = task->uldd_task;
- scmd = qc->scsicmd;
- } else {
- scmd = task->uldd_task;
- }
- }
-
- if (!scmd)
+ if (!rq)
return 0;

- blk_tag = blk_mq_unique_tag(scsi_cmd_to_rq(scmd));
+ blk_tag = blk_mq_unique_tag(rq);
return blk_mq_unique_tag_to_hwq(blk_tag);
}

--
2.35.3

2022-09-30 09:31:56

[permalink] [raw]

Subject: Re: [PATCH v2 4/6] scsi: pm8001: Use sas_task_find_rq() for tagging

On Fri, Sep 30, 2022 at 11:03 AM John Garry <[email protected]> wrote:
>
> The request associated with a scsi command coming from the block layer
> has a unique tag, so use that when possible for getting a CCB.
>
> Unfortunately we don't support reserved commands in the SCSI midlayer yet,
> so in the interim continue to manage those tags internally (along with
> tags for private commands).
>
> Signed-off-by: John Garry <[email protected]>
Reviewed-by: Jack Wang <[email protected]>
nice, I would expect this can improve performance, do you have numbers?
> ---
> drivers/scsi/pm8001/pm8001_init.c | 12 ++++--------
> drivers/scsi/pm8001/pm8001_sas.c | 16 ++++++++++++----
> drivers/scsi/pm8001/pm8001_sas.h | 11 ++++++++---
> drivers/scsi/pm8001/pm80xx_hwi.c | 17 +++--------------
> 4 files changed, 27 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
> index 0edc9857a8bd..abb884ddcaf9 100644
> --- a/drivers/scsi/pm8001/pm8001_init.c
> +++ b/drivers/scsi/pm8001/pm8001_init.c
> @@ -196,7 +196,7 @@ static void pm8001_free(struct pm8001_hba_info *pm8001_ha)
> }
> PM8001_CHIP_DISP->chip_iounmap(pm8001_ha);
> flush_workqueue(pm8001_wq);
> - bitmap_free(pm8001_ha->tags);
> + bitmap_free(pm8001_ha->rsvd_tags);
> kfree(pm8001_ha);
> }
>
> @@ -1208,18 +1208,15 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
> struct Scsi_Host *shost = pm8001_ha->shost;
> struct device *dev = pm8001_ha->dev;
> u32 max_out_io, ccb_count;
> - u32 can_queue;
> int i;
>
> max_out_io = pm8001_ha->main_cfg_tbl.pm80xx_tbl.max_out_io;
> ccb_count = min_t(int, PM8001_MAX_CCB, max_out_io);
>
> - /* Update to the scsi host*/
> - can_queue = ccb_count - PM8001_RESERVE_SLOT;
> - shost->can_queue = can_queue;
> + shost->can_queue = ccb_count - PM8001_RESERVE_SLOT;
>
> - pm8001_ha->tags = bitmap_zalloc(ccb_count, GFP_KERNEL);
> - if (!pm8001_ha->tags)
> + pm8001_ha->rsvd_tags = bitmap_zalloc(PM8001_RESERVE_SLOT, GFP_KERNEL);
> + if (!pm8001_ha->rsvd_tags)
> goto err_out;
>
> /* Memory region for ccb_info*/
> @@ -1244,7 +1241,6 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
> pm8001_ha->ccb_info[i].task = NULL;
> pm8001_ha->ccb_info[i].ccb_tag = PM8001_INVALID_TAG;
> pm8001_ha->ccb_info[i].device = NULL;
> - ++pm8001_ha->tags_num;
> }
>
> return 0;
> diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
> index 066dfa9f4683..d60bc311a4e9 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.c
> +++ b/drivers/scsi/pm8001/pm8001_sas.c
> @@ -65,9 +65,14 @@ static int pm8001_find_tag(struct sas_task *task, u32 *tag)
> */
> void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
> {
> - void *bitmap = pm8001_ha->tags;
> + void *bitmap = pm8001_ha->rsvd_tags;
> unsigned long flags;
>
> + if (tag < pm8001_ha->shost->can_queue)
> + return;
> +
> + tag -= pm8001_ha->shost->can_queue;
> +
> spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
> __clear_bit(tag, bitmap);
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> @@ -80,18 +85,21 @@ void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
> */
> int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
> {
> - void *bitmap = pm8001_ha->tags;
> + void *bitmap = pm8001_ha->rsvd_tags;
> unsigned long flags;
> unsigned int tag;
>
> spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
> - tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
> - if (tag >= pm8001_ha->tags_num) {
> + tag = find_first_zero_bit(bitmap, PM8001_RESERVE_SLOT);
> + if (tag >= PM8001_RESERVE_SLOT) {
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> return -SAS_QUEUE_FULL;
> }
> __set_bit(tag, bitmap);
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> +
> + /* reserved tags are in the upper region of the tagset */
> + tag += pm8001_ha->shost->can_queue;
> *tag_out = tag;
> return 0;
> }
> diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
> index 9acaadf02150..ba32b009f412 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.h
> +++ b/drivers/scsi/pm8001/pm8001_sas.h
> @@ -510,8 +510,7 @@ struct pm8001_hba_info {
> u32 chip_id;
> const struct pm8001_chip_info *chip;
> struct completion *nvmd_completion;
> - int tags_num;
> - unsigned long *tags;
> + unsigned long *rsvd_tags;
> struct pm8001_phy phy[PM8001_MAX_PHYS];
> struct pm8001_port port[PM8001_MAX_PHYS];
> u32 id;
> @@ -737,9 +736,15 @@ pm8001_ccb_alloc(struct pm8001_hba_info *pm8001_ha,
> struct pm8001_device *dev, struct sas_task *task)
> {
> struct pm8001_ccb_info *ccb;
> + struct request *rq = NULL;
> u32 tag;
>
> - if (pm8001_tag_alloc(pm8001_ha, &tag)) {
> + if (task)
> + rq = sas_task_find_rq(task);
> +
> + if (rq) {
> + tag = rq->tag;
> + } else if (pm8001_tag_alloc(pm8001_ha, &tag)) {
> pm8001_dbg(pm8001_ha, FAIL, "Failed to allocate a tag\n");
> return NULL;
> }
> diff --git a/drivers/scsi/pm8001/pm80xx_hwi.c b/drivers/scsi/pm8001/pm80xx_hwi.c
> index 4484c498bcb6..ed2d65d3749a 100644
> --- a/drivers/scsi/pm8001/pm80xx_hwi.c
> +++ b/drivers/scsi/pm8001/pm80xx_hwi.c
> @@ -4247,24 +4247,13 @@ static int check_enc_sat_cmd(struct sas_task *task)
>
> static u32 pm80xx_chip_get_q_index(struct sas_task *task)
> {
> - struct scsi_cmnd *scmd = NULL;
> + struct request *rq = sas_task_find_rq(task);
> u32 blk_tag;
>
> - if (task->uldd_task) {
> - struct ata_queued_cmd *qc;
> -
> - if (dev_is_sata(task->dev)) {
> - qc = task->uldd_task;
> - scmd = qc->scsicmd;
> - } else {
> - scmd = task->uldd_task;
> - }
> - }
> -
> - if (!scmd)
> + if (!rq)
> return 0;
>
> - blk_tag = blk_mq_unique_tag(scsi_cmd_to_rq(scmd));
> + blk_tag = blk_mq_unique_tag(rq);
> return blk_mq_unique_tag_to_hwq(blk_tag);
> }
>
> --
> 2.35.3
>

2022-09-30 09:33:34

[permalink] [raw]

Subject: [PATCH v2 6/6] scsi: mvsas: Use sas_task_find_rq() for tagging

The request associated with a scsi command coming from the block layer
has a unique tag, so use that when possible for getting a slot.

Unfortunately we don't support reserved commands in the SCSI midlayer yet.
As such, SMP tasks - as an example - will not have a request associated, so
in the interim continue to manage those tags for that type of sas_task
internally.

We reserve an arbitrary 4 tags for these internal tags. Indeed, we already
decrement MVS_RSVD_SLOTS by 2 for the shost can_queue when flag
MVF_FLAG_SOC is set. This change was made in commit 20b09c2992fef
("[PATCH] [SCSI] mvsas: add support for 94xx; layout change; bug fixes"),
but what those 2 slots are used for is not obvious.

Also make the tag management functions static, where possible.

Signed-off-by: John Garry <[email protected]>
---
drivers/scsi/mvsas/mv_defs.h | 1 +
drivers/scsi/mvsas/mv_init.c | 9 +++++----
drivers/scsi/mvsas/mv_sas.c | 38 ++++++++++++++++++++++++------------
drivers/scsi/mvsas/mv_sas.h | 7 +------
4 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/drivers/scsi/mvsas/mv_defs.h b/drivers/scsi/mvsas/mv_defs.h
index 7123a2efbf58..8ef174cd4d37 100644
--- a/drivers/scsi/mvsas/mv_defs.h
+++ b/drivers/scsi/mvsas/mv_defs.h
@@ -40,6 +40,7 @@ enum driver_configuration {
MVS_ATA_CMD_SZ = 96, /* SATA command table buffer size */
MVS_OAF_SZ = 64, /* Open address frame buffer size */
MVS_QUEUE_SIZE = 64, /* Support Queue depth */
+ MVS_RSVD_SLOTS = 4,
MVS_SOC_CAN_QUEUE = MVS_SOC_SLOTS - 2,
};

diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c
index c85fb812ad43..cfe84473a515 100644
--- a/drivers/scsi/mvsas/mv_init.c
+++ b/drivers/scsi/mvsas/mv_init.c
@@ -142,7 +142,7 @@ static void mvs_free(struct mvs_info *mvi)
scsi_host_put(mvi->shost);
list_for_each_entry(mwq, &mvi->wq_list, entry)
cancel_delayed_work(&mwq->work_q);
- kfree(mvi->tags);
+ kfree(mvi->rsvd_tags);
kfree(mvi);
}

@@ -284,7 +284,6 @@ static int mvs_alloc(struct mvs_info *mvi, struct Scsi_Host *shost)
printk(KERN_DEBUG "failed to create dma pool %s.\n", pool_name);
goto err_out;
}
- mvi->tags_num = slot_nr;

return 0;
err_out:
@@ -367,8 +366,8 @@ static struct mvs_info *mvs_pci_alloc(struct pci_dev *pdev,
mvi->sas = sha;
mvi->shost = shost;

- mvi->tags = kzalloc(MVS_CHIP_SLOT_SZ>>3, GFP_KERNEL);
- if (!mvi->tags)
+ mvi->rsvd_tags = bitmap_zalloc(MVS_RSVD_SLOTS, GFP_KERNEL);
+ if (!mvi->rsvd_tags)
goto err_out;

if (MVS_CHIP_DISP->chip_ioremap(mvi))
@@ -469,6 +468,8 @@ static void mvs_post_sas_ha_init(struct Scsi_Host *shost,
else
can_queue = MVS_CHIP_SLOT_SZ;

+ can_queue -= MVS_RSVD_SLOTS;
+
shost->sg_tablesize = min_t(u16, SG_ALL, MVS_MAX_SG);
shost->can_queue = can_queue;
mvi->shost->cmd_per_lun = MVS_QUEUE_SIZE;
diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
index 0810e6c930e1..00b3a2781d21 100644
--- a/drivers/scsi/mvsas/mv_sas.c
+++ b/drivers/scsi/mvsas/mv_sas.c
@@ -20,33 +20,39 @@ static int mvs_find_tag(struct mvs_info *mvi, struct sas_task *task, u32 *tag)
return 0;
}

-void mvs_tag_clear(struct mvs_info *mvi, u32 tag)
+static void mvs_tag_clear(struct mvs_info *mvi, u32 tag)
{
- void *bitmap = mvi->tags;
+ void *bitmap = mvi->rsvd_tags;
clear_bit(tag, bitmap);
}

-void mvs_tag_free(struct mvs_info *mvi, u32 tag)
+static void mvs_tag_free(struct mvs_info *mvi, u32 tag)
{
+ if (tag < mvi->shost->can_queue)
+ return;
+
+ tag -= mvi->shost->can_queue;
+
mvs_tag_clear(mvi, tag);
}

-void mvs_tag_set(struct mvs_info *mvi, unsigned int tag)
+static void mvs_tag_set(struct mvs_info *mvi, unsigned int tag)
{
- void *bitmap = mvi->tags;
+ void *bitmap = mvi->rsvd_tags;
set_bit(tag, bitmap);
}

-inline int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out)
+static int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out)
{
unsigned int index, tag;
- void *bitmap = mvi->tags;
+ void *bitmap = mvi->rsvd_tags;

- index = find_first_zero_bit(bitmap, mvi->tags_num);
+ index = find_first_zero_bit(bitmap, MVS_RSVD_SLOTS);
tag = index;
- if (tag >= mvi->tags_num)
+ if (tag >= MVS_RSVD_SLOTS)
return -SAS_QUEUE_FULL;
mvs_tag_set(mvi, tag);
+ tag += mvi->shost->can_queue;
*tag_out = tag;
return 0;
}
@@ -696,6 +702,7 @@ static int mvs_task_prep(struct sas_task *task, struct mvs_info *mvi, int is_tmf
struct mvs_task_exec_info tei;
struct mvs_slot_info *slot;
u32 tag = 0xdeadbeef, n_elem = 0;
+ struct request *rq;
int rc = 0;

if (!dev->port) {
@@ -760,9 +767,14 @@ static int mvs_task_prep(struct sas_task *task, struct mvs_info *mvi, int is_tmf
n_elem = task->num_scatter;
}

- rc = mvs_tag_alloc(mvi, &tag);
- if (rc)
- goto err_out;
+ rq = sas_task_find_rq(task);
+ if (rq) {
+ tag = rq->tag;
+ } else {
+ rc = mvs_tag_alloc(mvi, &tag);
+ if (rc)
+ goto err_out;
+ }

slot = &mvi->slot_info[tag];

@@ -857,7 +869,7 @@ int mvs_queue_command(struct sas_task *task, gfp_t gfp_flags)
static void mvs_slot_free(struct mvs_info *mvi, u32 rx_desc)
{
u32 slot_idx = rx_desc & RXQ_SLOT_MASK;
- mvs_tag_clear(mvi, slot_idx);
+ mvs_tag_free(mvi, slot_idx);
}

static void mvs_slot_task_free(struct mvs_info *mvi, struct sas_task *task,
diff --git a/drivers/scsi/mvsas/mv_sas.h b/drivers/scsi/mvsas/mv_sas.h
index fe57665bdb50..68df771e2975 100644
--- a/drivers/scsi/mvsas/mv_sas.h
+++ b/drivers/scsi/mvsas/mv_sas.h
@@ -370,8 +370,7 @@ struct mvs_info {
u32 chip_id;
const struct mvs_chip_info *chip;

- int tags_num;
- unsigned long *tags;
+ unsigned long *rsvd_tags;
/* further per-slot information */
struct mvs_phy phy[MVS_MAX_PHYS];
struct mvs_port port[MVS_MAX_PHYS];
@@ -424,10 +423,6 @@ struct mvs_task_exec_info {

/******************** function prototype *********************/
void mvs_get_sas_addr(void *buf, u32 buflen);
-void mvs_tag_clear(struct mvs_info *mvi, u32 tag);
-void mvs_tag_free(struct mvs_info *mvi, u32 tag);
-void mvs_tag_set(struct mvs_info *mvi, unsigned int tag);
-int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out);
void mvs_iounmap(void __iomem *regs);
int mvs_ioremap(struct mvs_info *mvi, int bar, int bar_ex);
void mvs_phys_reset(struct mvs_info *mvi, u32 phy_mask, int hard);
--
2.35.3

2022-09-30 09:35:23

by Jason Yan

[permalink] [raw]

Subject: Re: [PATCH v2 1/6] scsi: libsas: Add sas_task_find_rq()

On 2022/9/30 16:56, John Garry wrote:
> blk-mq already provides a unique tag per request. Some libsas LLDDs - like
> hisi_sas - already use this tag as the unique per-IO HW tag.
>
> Add a common function to provide the request associated with a sas_task
> for all libsas LLDDs.
>
> Signed-off-by: John Garry<[email protected]>
> ---
> include/scsi/libsas.h | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)

Reviewed-by: Jason Yan <[email protected]>

2022-09-30 09:35:43

[permalink] [raw]

Subject: [PATCH v2 2/6] scsi: hisi_sas: Use sas_task_find_rq()

Use sas_task_find_rq() to lookup the request per task for its driver tag.

Signed-off-by: John Garry <[email protected]>
Reviewed-by: Damien Le Moal <[email protected]>
---
drivers/scsi/hisi_sas/hisi_sas_main.c | 26 ++++++++------------------
1 file changed, 8 insertions(+), 18 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 4c37ae9eb6b6..1011dffed51f 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -177,13 +177,13 @@ static void hisi_sas_slot_index_set(struct hisi_hba *hisi_hba, int slot_idx)
}

static int hisi_sas_slot_index_alloc(struct hisi_hba *hisi_hba,
- struct scsi_cmnd *scsi_cmnd)
+ struct request *rq)
{
int index;
void *bitmap = hisi_hba->slot_index_tags;

- if (scsi_cmnd)
- return scsi_cmd_to_rq(scsi_cmnd)->tag;
+ if (rq)
+ return rq->tag;

spin_lock(&hisi_hba->lock);
index = find_next_zero_bit(bitmap, hisi_hba->slot_index_count,
@@ -461,11 +461,11 @@ static int hisi_sas_queue_command(struct sas_task *task, gfp_t gfp_flags)
struct asd_sas_port *sas_port = device->port;
struct hisi_sas_device *sas_dev = device->lldd_dev;
bool internal_abort = sas_is_internal_abort(task);
- struct scsi_cmnd *scmd = NULL;
struct hisi_sas_dq *dq = NULL;
struct hisi_sas_port *port;
struct hisi_hba *hisi_hba;
struct hisi_sas_slot *slot;
+ struct request *rq = NULL;
struct device *dev;
int rc;

@@ -520,22 +520,12 @@ static int hisi_sas_queue_command(struct sas_task *task, gfp_t gfp_flags)
return -ECOMM;
}

- if (task->uldd_task) {
- struct ata_queued_cmd *qc;
-
- if (dev_is_sata(device)) {
- qc = task->uldd_task;
- scmd = qc->scsicmd;
- } else {
- scmd = task->uldd_task;
- }
- }
-
- if (scmd) {
+ rq = sas_task_find_rq(task);
+ if (rq) {
unsigned int dq_index;
u32 blk_tag;

- blk_tag = blk_mq_unique_tag(scsi_cmd_to_rq(scmd));
+ blk_tag = blk_mq_unique_tag(rq);
dq_index = blk_mq_unique_tag_to_hwq(blk_tag);
dq = &hisi_hba->dq[dq_index];
} else {
@@ -580,7 +570,7 @@ static int hisi_sas_queue_command(struct sas_task *task, gfp_t gfp_flags)
if (!internal_abort && hisi_hba->hw->slot_index_alloc)
rc = hisi_hba->hw->slot_index_alloc(hisi_hba, device);
else
- rc = hisi_sas_slot_index_alloc(hisi_hba, scmd);
+ rc = hisi_sas_slot_index_alloc(hisi_hba, rq);

if (rc < 0)
goto err_out_dif_dma_unmap;
--
2.35.3

2022-09-30 09:53:23

[permalink] [raw]

Subject: Re: [PATCH v2 3/6] scsi: pm8001: Remove pm8001_tag_init()

On Fri, Sep 30, 2022 at 11:03 AM John Garry <[email protected]> wrote:
>
> From: Igor Pylypiv <[email protected]>
>
> In commit 5a141315ed7c ("scsi: pm80xx: Increase the number of outstanding
> I/O supported to 1024") the pm8001_ha->tags allocation was moved into
> pm8001_init_ccb_tag(). This changed the execution order of allocation.
> pm8001_tag_init() used to be called after the pm8001_ha->tags allocation
> and now it is called before the allocation.
>
> Before:
>
> pm8001_pci_probe()
> `--> pm8001_pci_alloc()
> `--> pm8001_alloc()
> `--> pm8001_ha->tags = kzalloc(...)
> `--> pm8001_tag_init(pm8001_ha); // OK: tags are allocated
>
> After:
>
> pm8001_pci_probe()
> `--> pm8001_pci_alloc()
> | `--> pm8001_alloc()
> | `--> pm8001_tag_init(pm8001_ha); // NOK: tags are not allocated
> |
> `--> pm8001_init_ccb_tag()
> `--> pm8001_ha->tags = kzalloc(...) // today it is bitmap_zalloc()
>
> Since pm8001_ha->tags_num is zero when pm8001_tag_init() is called it does
> nothing. Tags memory is allocated with bitmap_zalloc() so there is no need
> to manually clear each bit with pm8001_tag_free().
>
> Reviewed-by: Changyuan Lyu <[email protected]>
> Signed-off-by: Igor Pylypiv <[email protected]>
> Signed-off-by: John Garry <[email protected]>
> Reviewed-by: Damien Le Moal <[email protected]>
Reviewed-by: Jack Wang <[email protected]>
> ---
> drivers/scsi/pm8001/pm8001_init.c | 2 --
> drivers/scsi/pm8001/pm8001_sas.c | 7 -------
> drivers/scsi/pm8001/pm8001_sas.h | 1 -
> 3 files changed, 10 deletions(-)
>
> diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
> index a0028e130a7e..0edc9857a8bd 100644
> --- a/drivers/scsi/pm8001/pm8001_init.c
> +++ b/drivers/scsi/pm8001/pm8001_init.c
> @@ -436,8 +436,6 @@ static int pm8001_alloc(struct pm8001_hba_info *pm8001_ha,
> atomic_set(&pm8001_ha->devices[i].running_req, 0);
> }
> pm8001_ha->flags = PM8001F_INIT_TIME;
> - /* Initialize tags */
> - pm8001_tag_init(pm8001_ha);
> return 0;
>
> err_out_nodev:
> diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
> index d5ec29f69be3..066dfa9f4683 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.c
> +++ b/drivers/scsi/pm8001/pm8001_sas.c
> @@ -96,13 +96,6 @@ int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
> return 0;
> }
>
> -void pm8001_tag_init(struct pm8001_hba_info *pm8001_ha)
> -{
> - int i;
> - for (i = 0; i < pm8001_ha->tags_num; ++i)
> - pm8001_tag_free(pm8001_ha, i);
> -}
> -
> /**
> * pm8001_mem_alloc - allocate memory for pm8001.
> * @pdev: pci device.
> diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
> index 8ab0654327f9..9acaadf02150 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.h
> +++ b/drivers/scsi/pm8001/pm8001_sas.h
> @@ -632,7 +632,6 @@ extern struct workqueue_struct *pm8001_wq;
>
> /******************** function prototype *********************/
> int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out);
> -void pm8001_tag_init(struct pm8001_hba_info *pm8001_ha);
> u32 pm8001_get_ncq_tag(struct sas_task *task, u32 *tag);
> void pm8001_ccb_task_free(struct pm8001_hba_info *pm8001_ha,
> struct pm8001_ccb_info *ccb);
> --
> 2.35.3
>

2022-09-30 10:56:22

[permalink] [raw]

Subject: Re: [PATCH v2 4/6] scsi: pm8001: Use sas_task_find_rq() for tagging

On 30/09/2022 10:17, Jinpu Wang wrote:
> On Fri, Sep 30, 2022 at 11:03 AM John Garry<[email protected]> wrote:
>> The request associated with a scsi command coming from the block layer
>> has a unique tag, so use that when possible for getting a CCB.
>>
>> Unfortunately we don't support reserved commands in the SCSI midlayer yet,
>> so in the interim continue to manage those tags internally (along with
>> tags for private commands).
>>
>> Signed-off-by: John Garry<[email protected]>
> Reviewed-by: Jack Wang<[email protected]>
> nice, I would expect this can improve performance, do you have numbers?

Unfortunately my system hangs after I run for an appreciable period of
time. I normally get around it by turning on much heavy debug options,
but that would not be much use for performance testing.

But we did get considerable performance improvement for hisi_sas when we
made the equivalent change.

Damien, if you are interested then sharing any results would be great.

BTW, I do notice that we still have this global lock in delivery path
which should be removed at some stage:

int mvs_queue_command(struct sas_task *task, gfp_t gfp_flags)
{
...

spin_lock_irqsave(&mvi->lock, flags);
rc = mvs_task_prep(task, mvi, is_tmf, tmf, &pass);
...
spin_unlock_irqrestore(&mvi->lock, flags);
}

That really will affect performance...

Thanks,
John

2022-09-30 11:28:10

[permalink] [raw]

Subject: Re: [PATCH v2 4/6] scsi: pm8001: Use sas_task_find_rq() for tagging

On 30/09/2022 11:20, John Garry wrote:
> BTW, I do notice that we still have this global lock in delivery path
> which should be removed at some stage:
> > int mvs_queue_command(struct sas_task *task, gfp_t gfp_flags)
> {
>     ...
>
>     spin_lock_irqsave(&mvi->lock, flags);
>     rc = mvs_task_prep(task, mvi, is_tmf, tmf, &pass);
>     ...
>     spin_unlock_irqrestore(&mvi->lock, flags);
> }
>

oops... that's mvsas. But pm8001 does still use a big lock (which we
should get rid off):

int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags)
{
...
pm8001_dbg(pm8001_ha, IO, "pm8001_task_exec device\n");

spin_lock_irqsave(&pm8001_ha->lock, flags);

Thanks,
John

> That really will affect performance...

2022-10-04 05:46:47

[permalink] [raw]

Subject: Re: [PATCH v2 4/6] scsi: pm8001: Use sas_task_find_rq() for tagging

On Fri, Sep 30, 2022 at 1:05 PM John Garry <[email protected]> wrote:
>
> On 30/09/2022 11:20, John Garry wrote:
> > BTW, I do notice that we still have this global lock in delivery path
> > which should be removed at some stage:
> > > int mvs_queue_command(struct sas_task *task, gfp_t gfp_flags)
> > {
> > ...
> >
> > spin_lock_irqsave(&mvi->lock, flags);
> > rc = mvs_task_prep(task, mvi, is_tmf, tmf, &pass);
> > ...
> > spin_unlock_irqrestore(&mvi->lock, flags);
> > }
> >
>
> oops... that's mvsas. But pm8001 does still use a big lock (which we
> should get rid off):
Yes, would be great to get rid of the per ha lock.
>
> int pm8001_queue_command(struct sas_task *task, gfp_t gfp_flags)
> {
> ...
> pm8001_dbg(pm8001_ha, IO, "pm8001_task_exec device\n");
>
> spin_lock_irqsave(&pm8001_ha->lock, flags);
>
>
> Thanks,
> John
>
> > That really will affect performance...
>

2022-10-04 06:09:03

[permalink] [raw]

Subject: Re: [PATCH v2 3/6] scsi: pm8001: Remove pm8001_tag_init()

On 9/30/22 10:56, John Garry wrote:
> From: Igor Pylypiv <[email protected]>
>
> In commit 5a141315ed7c ("scsi: pm80xx: Increase the number of outstanding
> I/O supported to 1024") the pm8001_ha->tags allocation was moved into
> pm8001_init_ccb_tag(). This changed the execution order of allocation.
> pm8001_tag_init() used to be called after the pm8001_ha->tags allocation
> and now it is called before the allocation.
>
> Before:
>
> pm8001_pci_probe()
> `--> pm8001_pci_alloc()
> `--> pm8001_alloc()
> `--> pm8001_ha->tags = kzalloc(...)
> `--> pm8001_tag_init(pm8001_ha); // OK: tags are allocated
>
> After:
>
> pm8001_pci_probe()
> `--> pm8001_pci_alloc()
> | `--> pm8001_alloc()
> | `--> pm8001_tag_init(pm8001_ha); // NOK: tags are not allocated
> |
> `--> pm8001_init_ccb_tag()
> `--> pm8001_ha->tags = kzalloc(...) // today it is bitmap_zalloc()
>
> Since pm8001_ha->tags_num is zero when pm8001_tag_init() is called it does
> nothing. Tags memory is allocated with bitmap_zalloc() so there is no need
> to manually clear each bit with pm8001_tag_free().
>
> Reviewed-by: Changyuan Lyu <[email protected]>
> Signed-off-by: Igor Pylypiv <[email protected]>
> Signed-off-by: John Garry <[email protected]>
> Reviewed-by: Damien Le Moal <[email protected]>
> ---
> drivers/scsi/pm8001/pm8001_init.c | 2 --
> drivers/scsi/pm8001/pm8001_sas.c | 7 -------
> drivers/scsi/pm8001/pm8001_sas.h | 1 -
> 3 files changed, 10 deletions(-)
>
Reviewed-by: Hannes Reinecke <[email protected]>

Cheerx,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

2022-10-04 06:20:21

[permalink] [raw]

Subject: Re: [PATCH v2 5/6] scsi: mvsas: Delete mvs_tag_init()

On 9/30/22 10:56, John Garry wrote:
> All mvs_tag_init() does is zero the tag bitmap, but this is already done
> with the kzalloc() call to alloc the tags, so delete this unneeded
> function.
>
> Signed-off-by: John Garry <[email protected]>
> Reviewed-by: Damien Le Moal <[email protected]>
> ---
> drivers/scsi/mvsas/mv_init.c | 2 --
> drivers/scsi/mvsas/mv_sas.c | 7 -------
> drivers/scsi/mvsas/mv_sas.h | 1 -
> 3 files changed, 10 deletions(-)
>
Reviewed-by: Hannes Reinecke <[email protected]>

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

2022-10-04 06:26:32

[permalink] [raw]

Subject: Re: [PATCH v2 4/6] scsi: pm8001: Use sas_task_find_rq() for tagging

On 9/30/22 10:56, John Garry wrote:
> The request associated with a scsi command coming from the block layer
> has a unique tag, so use that when possible for getting a CCB.
>
> Unfortunately we don't support reserved commands in the SCSI midlayer yet,
> so in the interim continue to manage those tags internally (along with
> tags for private commands).
>
> Signed-off-by: John Garry <[email protected]>
> ---
> drivers/scsi/pm8001/pm8001_init.c | 12 ++++--------
> drivers/scsi/pm8001/pm8001_sas.c | 16 ++++++++++++----
> drivers/scsi/pm8001/pm8001_sas.h | 11 ++++++++---
> drivers/scsi/pm8001/pm80xx_hwi.c | 17 +++--------------
> 4 files changed, 27 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
> index 0edc9857a8bd..abb884ddcaf9 100644
> --- a/drivers/scsi/pm8001/pm8001_init.c
> +++ b/drivers/scsi/pm8001/pm8001_init.c
> @@ -196,7 +196,7 @@ static void pm8001_free(struct pm8001_hba_info *pm8001_ha)
> }
> PM8001_CHIP_DISP->chip_iounmap(pm8001_ha);
> flush_workqueue(pm8001_wq);
> - bitmap_free(pm8001_ha->tags);
> + bitmap_free(pm8001_ha->rsvd_tags);
> kfree(pm8001_ha);
> }
>
> @@ -1208,18 +1208,15 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
> struct Scsi_Host *shost = pm8001_ha->shost;
> struct device *dev = pm8001_ha->dev;
> u32 max_out_io, ccb_count;
> - u32 can_queue;
> int i;
>
> max_out_io = pm8001_ha->main_cfg_tbl.pm80xx_tbl.max_out_io;
> ccb_count = min_t(int, PM8001_MAX_CCB, max_out_io);
>
> - /* Update to the scsi host*/
> - can_queue = ccb_count - PM8001_RESERVE_SLOT;
> - shost->can_queue = can_queue;
> + shost->can_queue = ccb_count - PM8001_RESERVE_SLOT;
>
> - pm8001_ha->tags = bitmap_zalloc(ccb_count, GFP_KERNEL);
> - if (!pm8001_ha->tags)
> + pm8001_ha->rsvd_tags = bitmap_zalloc(PM8001_RESERVE_SLOT, GFP_KERNEL);
> + if (!pm8001_ha->rsvd_tags)
> goto err_out;
>
> /* Memory region for ccb_info*/
> @@ -1244,7 +1241,6 @@ static int pm8001_init_ccb_tag(struct pm8001_hba_info *pm8001_ha)
> pm8001_ha->ccb_info[i].task = NULL;
> pm8001_ha->ccb_info[i].ccb_tag = PM8001_INVALID_TAG;
> pm8001_ha->ccb_info[i].device = NULL;
> - ++pm8001_ha->tags_num;
> }
>
> return 0;
> diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
> index 066dfa9f4683..d60bc311a4e9 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.c
> +++ b/drivers/scsi/pm8001/pm8001_sas.c
> @@ -65,9 +65,14 @@ static int pm8001_find_tag(struct sas_task *task, u32 *tag)
> */
> void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
> {
> - void *bitmap = pm8001_ha->tags;
> + void *bitmap = pm8001_ha->rsvd_tags;
> unsigned long flags;
>
> + if (tag < pm8001_ha->shost->can_queue)
> + return;
> +
> + tag -= pm8001_ha->shost->can_queue;
> +
> spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
> __clear_bit(tag, bitmap);
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> @@ -80,18 +85,21 @@ void pm8001_tag_free(struct pm8001_hba_info *pm8001_ha, u32 tag)
> */
> int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
> {
> - void *bitmap = pm8001_ha->tags;
> + void *bitmap = pm8001_ha->rsvd_tags;
> unsigned long flags;
> unsigned int tag;
>
> spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
> - tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
> - if (tag >= pm8001_ha->tags_num) {
> + tag = find_first_zero_bit(bitmap, PM8001_RESERVE_SLOT);
> + if (tag >= PM8001_RESERVE_SLOT) {
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> return -SAS_QUEUE_FULL;
> }
> __set_bit(tag, bitmap);
> spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
> +
> + /* reserved tags are in the upper region of the tagset */
> + tag += pm8001_ha->shost->can_queue;
> *tag_out = tag;
> return 0;
> }
Can you move the reserved tags to the _lower_ region of the tagset?
That way the tag allocation scheme matches with what the block-layer
does, and the eventual conversion to reserved tags becomes easier.

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

2022-10-04 06:28:01

[permalink] [raw]

Subject: Re: [PATCH v2 2/6] scsi: hisi_sas: Use sas_task_find_rq()

On 9/30/22 10:56, John Garry wrote:
> Use sas_task_find_rq() to lookup the request per task for its driver tag.
>
> Signed-off-by: John Garry <[email protected]>
> Reviewed-by: Damien Le Moal <[email protected]>
> ---
> drivers/scsi/hisi_sas/hisi_sas_main.c | 26 ++++++++------------------
> 1 file changed, 8 insertions(+), 18 deletions(-)
>
Reviewed-by: Hannes Reinecke <[email protected]>

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

2022-10-04 06:29:33

[permalink] [raw]

Subject: Re: [PATCH v2 1/6] scsi: libsas: Add sas_task_find_rq()

On 9/30/22 10:56, John Garry wrote:
> blk-mq already provides a unique tag per request. Some libsas LLDDs - like
> hisi_sas - already use this tag as the unique per-IO HW tag.
>
> Add a common function to provide the request associated with a sas_task
> for all libsas LLDDs.
>
> Signed-off-by: John Garry <[email protected]>
> ---
> include/scsi/libsas.h | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
Reviewed-by: Hannes Reinecke <[email protected]>

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

2022-10-04 06:29:34

[permalink] [raw]

Subject: Re: [PATCH v2 6/6] scsi: mvsas: Use sas_task_find_rq() for tagging

On 9/30/22 10:56, John Garry wrote:
> The request associated with a scsi command coming from the block layer
> has a unique tag, so use that when possible for getting a slot.
>
> Unfortunately we don't support reserved commands in the SCSI midlayer yet.
> As such, SMP tasks - as an example - will not have a request associated, so
> in the interim continue to manage those tags for that type of sas_task
> internally.
>
> We reserve an arbitrary 4 tags for these internal tags. Indeed, we already
> decrement MVS_RSVD_SLOTS by 2 for the shost can_queue when flag
> MVF_FLAG_SOC is set. This change was made in commit 20b09c2992fef
> ("[PATCH] [SCSI] mvsas: add support for 94xx; layout change; bug fixes"),
> but what those 2 slots are used for is not obvious.
>
> Also make the tag management functions static, where possible.
>
> Signed-off-by: John Garry <[email protected]>
> ---
> drivers/scsi/mvsas/mv_defs.h | 1 +
> drivers/scsi/mvsas/mv_init.c | 9 +++++----
> drivers/scsi/mvsas/mv_sas.c | 38 ++++++++++++++++++++++++------------
> drivers/scsi/mvsas/mv_sas.h | 7 +------
> 4 files changed, 32 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/scsi/mvsas/mv_defs.h b/drivers/scsi/mvsas/mv_defs.h
> index 7123a2efbf58..8ef174cd4d37 100644
> --- a/drivers/scsi/mvsas/mv_defs.h
> +++ b/drivers/scsi/mvsas/mv_defs.h
> @@ -40,6 +40,7 @@ enum driver_configuration {
> MVS_ATA_CMD_SZ = 96, /* SATA command table buffer size */
> MVS_OAF_SZ = 64, /* Open address frame buffer size */
> MVS_QUEUE_SIZE = 64, /* Support Queue depth */
> + MVS_RSVD_SLOTS = 4,
> MVS_SOC_CAN_QUEUE = MVS_SOC_SLOTS - 2,
> };
>
> diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c
> index c85fb812ad43..cfe84473a515 100644
> --- a/drivers/scsi/mvsas/mv_init.c
> +++ b/drivers/scsi/mvsas/mv_init.c
> @@ -142,7 +142,7 @@ static void mvs_free(struct mvs_info *mvi)
> scsi_host_put(mvi->shost);
> list_for_each_entry(mwq, &mvi->wq_list, entry)
> cancel_delayed_work(&mwq->work_q);
> - kfree(mvi->tags);
> + kfree(mvi->rsvd_tags);
> kfree(mvi);
> }
>
> @@ -284,7 +284,6 @@ static int mvs_alloc(struct mvs_info *mvi, struct Scsi_Host *shost)
> printk(KERN_DEBUG "failed to create dma pool %s.\n", pool_name);
> goto err_out;
> }
> - mvi->tags_num = slot_nr;
>
> return 0;
> err_out:
> @@ -367,8 +366,8 @@ static struct mvs_info *mvs_pci_alloc(struct pci_dev *pdev,
> mvi->sas = sha;
> mvi->shost = shost;
>
> - mvi->tags = kzalloc(MVS_CHIP_SLOT_SZ>>3, GFP_KERNEL);
> - if (!mvi->tags)
> + mvi->rsvd_tags = bitmap_zalloc(MVS_RSVD_SLOTS, GFP_KERNEL);
> + if (!mvi->rsvd_tags)
> goto err_out;
>
> if (MVS_CHIP_DISP->chip_ioremap(mvi))
> @@ -469,6 +468,8 @@ static void mvs_post_sas_ha_init(struct Scsi_Host *shost,
> else
> can_queue = MVS_CHIP_SLOT_SZ;
>
> + can_queue -= MVS_RSVD_SLOTS;
> +
> shost->sg_tablesize = min_t(u16, SG_ALL, MVS_MAX_SG);
> shost->can_queue = can_queue;
> mvi->shost->cmd_per_lun = MVS_QUEUE_SIZE;
> diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
> index 0810e6c930e1..00b3a2781d21 100644
> --- a/drivers/scsi/mvsas/mv_sas.c
> +++ b/drivers/scsi/mvsas/mv_sas.c
> @@ -20,33 +20,39 @@ static int mvs_find_tag(struct mvs_info *mvi, struct sas_task *task, u32 *tag)
> return 0;
> }
>
> -void mvs_tag_clear(struct mvs_info *mvi, u32 tag)
> +static void mvs_tag_clear(struct mvs_info *mvi, u32 tag)
> {
> - void *bitmap = mvi->tags;
> + void *bitmap = mvi->rsvd_tags;
> clear_bit(tag, bitmap);
> }
>
> -void mvs_tag_free(struct mvs_info *mvi, u32 tag)
> +static void mvs_tag_free(struct mvs_info *mvi, u32 tag)
> {
> + if (tag < mvi->shost->can_queue)
> + return;
> +
> + tag -= mvi->shost->can_queue;
> +
> mvs_tag_clear(mvi, tag);
> }
>
> -void mvs_tag_set(struct mvs_info *mvi, unsigned int tag)
> +static void mvs_tag_set(struct mvs_info *mvi, unsigned int tag)
> {
> - void *bitmap = mvi->tags;
> + void *bitmap = mvi->rsvd_tags;
> set_bit(tag, bitmap);
> }
>
> -inline int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out)
> +static int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out)
> {
> unsigned int index, tag;
> - void *bitmap = mvi->tags;
> + void *bitmap = mvi->rsvd_tags;
>
> - index = find_first_zero_bit(bitmap, mvi->tags_num);
> + index = find_first_zero_bit(bitmap, MVS_RSVD_SLOTS);
> tag = index;
> - if (tag >= mvi->tags_num)
> + if (tag >= MVS_RSVD_SLOTS)
> return -SAS_QUEUE_FULL;
> mvs_tag_set(mvi, tag);
> + tag += mvi->shost->can_queue;
> *tag_out = tag;
> return 0;
> }

Also here: please move the reserved tags to the front, such that the tag
allocation scheme matches with the blk-mq tag allocation scheme.

Cheers,

Hannes
--
Dr. Hannes Reinecke Kernel Storage Architect
[email protected] +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman

2022-10-04 09:03:27