Commit fbd36818 authored by Sergey Gorenko's avatar Sergey Gorenko Committed by Jason Gunthorpe

IB/srp: Use the IB_DEVICE_SG_GAPS_REG HCA feature if supported

If a HCA supports the SG_GAPS_REG feature then fewer memory regions
are required per command. This patch reduces the number of memory
regions that is allocated per SRP session.
Signed-off-by: default avatarSergey Gorenko <sergeygo@mellanox.com>
Reviewed-by: default avatarMax Gurtovoy <maxg@mellanox.com>
Tested-by: default avatarLaurence Oberman <loberman@redhat.com>
Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
Acked-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 41904439
......@@ -431,6 +431,7 @@ static struct srp_fr_pool *srp_create_fr_pool(struct ib_device *device,
struct srp_fr_desc *d;
struct ib_mr *mr;
int i, ret = -EINVAL;
enum ib_mr_type mr_type;
if (pool_size <= 0)
goto err;
......@@ -444,9 +445,13 @@ static struct srp_fr_pool *srp_create_fr_pool(struct ib_device *device,
spin_lock_init(&pool->lock);
INIT_LIST_HEAD(&pool->free_list);
if (device->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG)
mr_type = IB_MR_TYPE_SG_GAPS;
else
mr_type = IB_MR_TYPE_MEM_REG;
for (i = 0, d = &pool->desc[0]; i < pool->size; i++, d++) {
mr = ib_alloc_mr(pd, IB_MR_TYPE_MEM_REG,
max_page_list_len);
mr = ib_alloc_mr(pd, mr_type, max_page_list_len);
if (IS_ERR(mr)) {
ret = PTR_ERR(mr);
if (ret == -ENOMEM)
......@@ -2996,8 +3001,9 @@ static int srp_slave_alloc(struct scsi_device *sdev)
struct Scsi_Host *shost = sdev->host;
struct srp_target_port *target = host_to_target(shost);
struct srp_device *srp_dev = target->srp_host->srp_dev;
struct ib_device *ibdev = srp_dev->dev;
if (true)
if (!(ibdev->attrs.device_cap_flags & IB_DEVICE_SG_GAPS_REG))
blk_queue_virt_boundary(sdev->request_queue,
~srp_dev->mr_page_mask);
......@@ -3775,26 +3781,36 @@ static ssize_t srp_create_target(struct device *dev,
}
if (srp_dev->use_fast_reg || srp_dev->use_fmr) {
/*
* FR and FMR can only map one HCA page per entry. If the
* start address is not aligned on a HCA page boundary two
* entries will be used for the head and the tail although
* these two entries combined contain at most one HCA page of
* data. Hence the "+ 1" in the calculation below.
*
* The indirect data buffer descriptor is contiguous so the
* memory for that buffer will only be registered if
* register_always is true. Hence add one to mr_per_cmd if
* register_always has been set.
*/
bool gaps_reg = (ibdev->attrs.device_cap_flags &
IB_DEVICE_SG_GAPS_REG);
max_sectors_per_mr = srp_dev->max_pages_per_mr <<
(ilog2(srp_dev->mr_page_size) - 9);
mr_per_cmd = register_always +
(target->scsi_host->max_sectors + 1 +
max_sectors_per_mr - 1) / max_sectors_per_mr;
if (!gaps_reg) {
/*
* FR and FMR can only map one HCA page per entry. If
* the start address is not aligned on a HCA page
* boundary two entries will be used for the head and
* the tail although these two entries combined
* contain at most one HCA page of data. Hence the "+
* 1" in the calculation below.
*
* The indirect data buffer descriptor is contiguous
* so the memory for that buffer will only be
* registered if register_always is true. Hence add
* one to mr_per_cmd if register_always has been set.
*/
mr_per_cmd = register_always +
(target->scsi_host->max_sectors + 1 +
max_sectors_per_mr - 1) / max_sectors_per_mr;
} else {
mr_per_cmd = register_always +
(target->sg_tablesize +
srp_dev->max_pages_per_mr - 1) /
srp_dev->max_pages_per_mr;
}
pr_debug("max_sectors = %u; max_pages_per_mr = %u; mr_page_size = %u; max_sectors_per_mr = %u; mr_per_cmd = %u\n",
target->scsi_host->max_sectors,
srp_dev->max_pages_per_mr, srp_dev->mr_page_size,
target->scsi_host->max_sectors, srp_dev->max_pages_per_mr, srp_dev->mr_page_size,
max_sectors_per_mr, mr_per_cmd);
}
......
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