[PATCH 07/23] scsi: add a dma_alignment field to the host and host template

Christoph Hellwig
2024-04-09T14:38:21Z

Get drivers out of the business of having to call the block layer
dma alignment limits helpers themselves.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: John Garry <john.g.garry@oracle.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
drivers/firewire/sbp2.c | 6 ------
drivers/message/fusion/mptfc.c | 1 +
drivers/message/fusion/mptsas.c | 1 +
drivers/message/fusion/mptscsih.c | 2 --
drivers/message/fusion/mptspi.c | 1 +
drivers/scsi/hosts.c | 6 ++++++
drivers/scsi/iscsi_tcp.c | 2 +-
drivers/scsi/qla2xxx/qla_os.c | 6 +++---
drivers/scsi/scsi_lib.c | 11 ++---------
drivers/staging/rts5208/rtsx.c | 24 ++++++++++++------------
drivers/usb/image/microtek.c | 8 +-------
drivers/usb/storage/scsiglue.c | 11 +++++------
drivers/usb/storage/uas.c | 13 ++++++-------
include/scsi/scsi_host.h | 3 +++
14 files changed, 42 insertions(+), 53 deletions(-)

diff --git a/drivers/firewire/sbp2.c b/drivers/firewire/sbp2.c
index e779d866022b9f..8f7810b2a4c10f 100644
--- a/drivers/firewire/sbp2.c
+++ b/drivers/firewire/sbp2.c
@@ -1500,12 +1500,6 @@ static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)

sdev->allow_restart = 1;

- /*
- * SBP-2 does not require any alignment, but we set it anyway
- * for compatibility with earlier versions of this driver.
- */
- blk_queue_update_dma_alignment(sdev->request_queue, 4 - 1);
-
if (lu->tgt->workarounds & SBP2_WORKAROUND_INQUIRY_36)
sdev->inquiry_len = 36;

diff --git a/drivers/message/fusion/mptfc.c b/drivers/message/fusion/mptfc.c
index c459f709107b7c..a3c17c4fe69c54 100644
--- a/drivers/message/fusion/mptfc.c
+++ b/drivers/message/fusion/mptfc.c
@@ -129,6 +129,7 @@ static const struct scsi_host_template mptfc_driver_template = {
.sg_tablesize = MPT_SCSI_SG_DEPTH,
.max_sectors = 8192,
.cmd_per_lun = 7,
+ .dma_alignment = 511,
.shost_groups = mptscsih_host_attr_groups,
};

diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c
index 300f8e955a5319..30cb4f64e77047 100644
--- a/drivers/message/fusion/mptsas.c
+++ b/drivers/message/fusion/mptsas.c
@@ -2020,6 +2020,7 @@ static const struct scsi_host_template mptsas_driver_template = {
.sg_tablesize = MPT_SCSI_SG_DEPTH,
.max_sectors = 8192,
.cmd_per_lun = 7,
+ .dma_alignment = 511,
.shost_groups = mptscsih_host_attr_groups,
.no_write_same = 1,
};
diff --git a/drivers/message/fusion/mptscsih.c b/drivers/message/fusion/mptscsih.c
index 9080a73b4ea64a..6c3f25cc33ff99 100644
--- a/drivers/message/fusion/mptscsih.c
+++ b/drivers/message/fusion/mptscsih.c
@@ -2438,8 +2438,6 @@ mptscsih_slave_configure(struct scsi_device *sdev)
"tagged %d, simple %d\n",
ioc->name,sdev->tagged_supported, sdev->simple_tags));

- blk_queue_dma_alignment (sdev->request_queue, 512 - 1);
-
return 0;
}

diff --git a/drivers/message/fusion/mptspi.c b/drivers/message/fusion/mptspi.c
index 6c5920db1e9dc5..574b882c9a8540 100644
--- a/drivers/message/fusion/mptspi.c
+++ b/drivers/message/fusion/mptspi.c
@@ -843,6 +843,7 @@ static const struct scsi_host_template mptspi_driver_template = {
.sg_tablesize = MPT_SCSI_SG_DEPTH,
.max_sectors = 8192,
.cmd_per_lun = 7,
+ .dma_alignment = 511,
.shost_groups = mptscsih_host_attr_groups,
};

diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 4f495a41ec4aae..a67a98bd7ae2d7 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -478,6 +478,12 @@ struct Scsi_Host *scsi_host_alloc(const struct scsi_host_template *sht, int priv
else
shost->max_segment_size = BLK_MAX_SEGMENT_SIZE;

+ /* 32-byte (dword) is a common minimum for HBAs. */
+ if (sht->dma_alignment)
+ shost->dma_alignment = sht->dma_alignment;
+ else
+ shost->dma_alignment = 3;
+
/*
* assume a 4GB boundary, if not set
*/
diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 8e14cea15f9808..60688f18fac6f7 100644
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -943,6 +943,7 @@ iscsi_sw_tcp_session_create(struct iscsi_endpoint *ep, uint16_t cmds_max,
shost->max_id = 0;
shost->max_channel = 0;
shost->max_cmd_len = SCSI_MAX_VARLEN_CDB_SIZE;
+ shost->dma_alignment = 0;

rc = iscsi_host_get_max_scsi_cmds(shost, cmds_max);
if (rc < 0)
@@ -1065,7 +1066,6 @@ static int iscsi_sw_tcp_slave_configure(struct scsi_device *sdev)
if (conn->datadgst_en)
blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES,
sdev->request_queue);
- blk_queue_dma_alignment(sdev->request_queue, 0);
return 0;
}

diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 6a1900e96a5a5f..fcb06df2ce4e68 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -1957,9 +1957,6 @@ qla2xxx_slave_configure(struct scsi_device *sdev)
scsi_qla_host_t *vha = shost_priv(sdev->host);
struct req_que *req = vha->req;

- if (IS_T10_PI_CAPABLE(vha->hw))
- blk_queue_update_dma_alignment(sdev->request_queue, 0x7);
-
scsi_change_queue_depth(sdev, req->max_q_depth);
return 0;
}
@@ -3575,6 +3572,9 @@ qla2x00_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
QLA_SG_ALL : 128;
}

+ if (IS_T10_PI_CAPABLE(base_vha->hw))
+ host->dma_alignment = 0x7;
+
ret = scsi_add_host(host, &pdev->dev);
if (ret)
goto probe_failed;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index f1936f98abe3e2..26b51406c477e3 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1985,15 +1985,8 @@ void scsi_init_limits(struct Scsi_Host *shost, struct queue_limits *lim)
lim->seg_boundary_mask = shost->dma_boundary;
lim->max_segment_size = shost->max_segment_size;
lim->virt_boundary_mask = shost->virt_boundary_mask;
-
- /*
- * Set a reasonable default alignment: The larger of 32-byte (dword),
- * which is a common minimum for HBAs, and the minimum DMA alignment,
- * which is set by the platform.
- *
- * Devices that require a bigger alignment can increase it later.
- */
- lim->dma_alignment = max(4, dma_get_cache_alignment()) - 1;
+ lim->dma_alignment = max_t(unsigned int,
+ shost->dma_alignment, dma_get_cache_alignment() - 1);

if (shost->no_highmem)
lim->bounce = BLK_BOUNCE_HIGH;
diff --git a/drivers/staging/rts5208/rtsx.c b/drivers/staging/rts5208/rtsx.c
index 86d32e3b3282a5..c4f54c311d0549 100644
--- a/drivers/staging/rts5208/rtsx.c
+++ b/drivers/staging/rts5208/rtsx.c
@@ -70,18 +70,6 @@ static int slave_alloc(struct scsi_device *sdev)

static int slave_configure(struct scsi_device *sdev)
{
- /*
- * Scatter-gather buffers (all but the last) must have a length
- * divisible by the bulk maxpacket size. Otherwise a data packet
- * would end up being short, causing a premature end to the data
- * transfer. Since high-speed bulk pipes have a maxpacket size
- * of 512, we'll use that as the scsi device queue's DMA alignment
- * mask. Guaranteeing proper alignment of the first buffer will
- * have the desired effect because, except at the beginning and
- * the end, scatter-gather buffers follow page boundaries.
- */
- blk_queue_dma_alignment(sdev->request_queue, (512 - 1));
-
/* Set the SCSI level to at least 2. We'll leave it at 3 if that's
* what is originally reported. We need this to avoid confusing
* the SCSI layer with devices that report 0 or 1, but need 10-byte
@@ -219,6 +207,18 @@ static const struct scsi_host_template rtsx_host_template = {
/* limit the total size of a transfer to 120 KB */
.max_sectors = 240,

+ /*
+ * Scatter-gather buffers (all but the last) must have a length
+ * divisible by the bulk maxpacket size. Otherwise a data packet
+ * would end up being short, causing a premature end to the data
+ * transfer. Since high-speed bulk pipes have a maxpacket size
+ * of 512, we'll use that as the scsi device queue's DMA alignment
+ * mask. Guaranteeing proper alignment of the first buffer will
+ * have the desired effect because, except at the beginning and
+ * the end, scatter-gather buffers follow page boundaries.
+ */
+ .dma_alignment = 511,
+
/* emulated HBA */
.emulated = 1,

diff --git a/drivers/usb/image/microtek.c b/drivers/usb/image/microtek.c
index 8c8fa71c69c411..9f758241d9d376 100644
--- a/drivers/usb/image/microtek.c
+++ b/drivers/usb/image/microtek.c
@@ -328,12 +328,6 @@ static int mts_slave_alloc (struct scsi_device *s)
return 0;
}

-static int mts_slave_configure (struct scsi_device *s)
-{
- blk_queue_dma_alignment(s->request_queue, (512 - 1));
- return 0;
-}
-
static int mts_scsi_abort(struct scsi_cmnd *srb)
{
struct mts_desc* desc = (struct mts_desc*)(srb->device->host->hostdata[0]);
@@ -631,8 +625,8 @@ static const struct scsi_host_template mts_scsi_host_template = {
.can_queue = 1,
.this_id = -1,
.emulated = 1,
+ .dma_alignment = 511,
.slave_alloc = mts_slave_alloc,
- .slave_configure = mts_slave_configure,
.max_sectors= 256, /* 128 K */
};

diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 1d14c678f3d3e3..eb4ba03e082d89 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -75,12 +75,6 @@ static int slave_alloc (struct scsi_device *sdev)
*/
sdev->inquiry_len = 36;

- /*
- * Some host controllers may have alignment requirements.
- * We'll play it safe by requiring 512-byte alignment always.
- */
- blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
-
/* Tell the SCSI layer if we know there is more than one LUN */
if (us->protocol == USB_PR_BULK && us->max_lun > 0)
sdev->sdev_bflags |= BLIST_FORCELUN;
@@ -638,6 +632,11 @@ static const struct scsi_host_template usb_stor_host_template = {
/* lots of sg segments can be handled */
.sg_tablesize = SG_MAX_SEGMENTS,

+ /*
+ * Some host controllers may have alignment requirements.
+ * We'll play it safe by requiring 512-byte alignment always.
+ */
+ .dma_alignment = 511,

/*
* Limit the total size of a transfer to 120 KB.
diff --git a/drivers/usb/storage/uas.c b/drivers/usb/storage/uas.c
index 71ace274761f18..0668182e1c469c 100644
--- a/drivers/usb/storage/uas.c
+++ b/drivers/usb/storage/uas.c
@@ -824,13 +824,6 @@ static int uas_slave_alloc(struct scsi_device *sdev)

sdev->hostdata = devinfo;

- /*
- * The protocol has no requirements on alignment in the strict sense.
- * Controllers may or may not have alignment restrictions.
- * As this is not exported, we use an extremely conservative guess.
- */
- blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
-
if (devinfo->flags & US_FL_MAX_SECTORS_64)
blk_queue_max_hw_sectors(sdev->request_queue, 64);
else if (devinfo->flags & US_FL_MAX_SECTORS_240)
@@ -912,6 +905,12 @@ static const struct scsi_host_template uas_host_template = {
.eh_device_reset_handler = uas_eh_device_reset_handler,
.this_id = -1,
.skip_settle_delay = 1,
+ /*
+ * The protocol has no requirements on alignment in the strict sense.
+ * Controllers may or may not have alignment restrictions.
+ * As this is not exported, we use an extremely conservative guess.
+ */
+ .dma_alignment = 511,
.dma_boundary = PAGE_SIZE - 1,
.cmd_size = sizeof(struct uas_cmd_info),
};
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 6d77c48e8311fb..b0948ab69e0fa6 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -405,6 +405,8 @@ struct scsi_host_template {
*/
unsigned int max_segment_size;

+ unsigned int dma_alignment;
+
/*
* DMA scatter gather segment boundary limit. A segment crossing this
* boundary will be split in two.
@@ -614,6 +616,7 @@ struct Scsi_Host {
unsigned int max_sectors;
unsigned int opt_sectors;
unsigned int max_segment_size;
+ unsigned int dma_alignment;
unsigned long dma_boundary;
unsigned long virt_boundary_mask;
/*
--
2.39.2