IB/srp: Use FMRs to map gather/scatter lists
Create an SRP FMR pool on HCAs that support FMRs, and use FMRs to map
gather/scatter lists that have more than one entry into a single
memory region that appears virtually contiguous to the SRP target
(which is the RDMA initiator).
This patch bails out on FMR mapping for SCSI commands where the
gather/scatter list cannot be mapped into a single FMR because there
are sub-page-sized entries in middle of the list. An unaligned
start or end of the list is OK.
Based on a patch by Vu Pham <vuhuong@mellanox.com>.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c
index 9cbdffa..9c37313 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.c
+++ b/drivers/infiniband/ulp/srp/ib_srp.c
@@ -105,7 +105,8 @@
if (!iu->buf)
goto out_free_iu;
- iu->dma = dma_map_single(host->dev->dma_device, iu->buf, size, direction);
+ iu->dma = dma_map_single(host->dev->dev->dma_device,
+ iu->buf, size, direction);
if (dma_mapping_error(iu->dma))
goto out_free_buf;
@@ -127,7 +128,8 @@
if (!iu)
return;
- dma_unmap_single(host->dev->dma_device, iu->dma, iu->size, iu->direction);
+ dma_unmap_single(host->dev->dev->dma_device,
+ iu->dma, iu->size, iu->direction);
kfree(iu->buf);
kfree(iu);
}
@@ -147,7 +149,7 @@
if (!attr)
return -ENOMEM;
- ret = ib_find_cached_pkey(target->srp_host->dev,
+ ret = ib_find_cached_pkey(target->srp_host->dev->dev,
target->srp_host->port,
be16_to_cpu(target->path.pkey),
&attr->pkey_index);
@@ -179,7 +181,7 @@
if (!init_attr)
return -ENOMEM;
- target->cq = ib_create_cq(target->srp_host->dev, srp_completion,
+ target->cq = ib_create_cq(target->srp_host->dev->dev, srp_completion,
NULL, target, SRP_CQ_SIZE);
if (IS_ERR(target->cq)) {
ret = PTR_ERR(target->cq);
@@ -198,7 +200,7 @@
init_attr->send_cq = target->cq;
init_attr->recv_cq = target->cq;
- target->qp = ib_create_qp(target->srp_host->pd, init_attr);
+ target->qp = ib_create_qp(target->srp_host->dev->pd, init_attr);
if (IS_ERR(target->qp)) {
ret = PTR_ERR(target->qp);
ib_destroy_cq(target->cq);
@@ -250,7 +252,7 @@
init_completion(&target->done);
- target->path_query_id = ib_sa_path_rec_get(target->srp_host->dev,
+ target->path_query_id = ib_sa_path_rec_get(target->srp_host->dev->dev,
target->srp_host->port,
&target->path,
IB_SA_PATH_REC_DGID |
@@ -421,6 +423,11 @@
scmnd->sc_data_direction != DMA_FROM_DEVICE))
return;
+ if (req->fmr) {
+ ib_fmr_pool_unmap(req->fmr);
+ req->fmr = NULL;
+ }
+
/*
* This handling of non-SG commands can be killed when the
* SCSI midlayer no longer generates non-SG commands.
@@ -433,7 +440,7 @@
scat = &req->fake_sg;
}
- dma_unmap_sg(target->srp_host->dev->dma_device, scat, nents,
+ dma_unmap_sg(target->srp_host->dev->dev->dma_device, scat, nents,
scmnd->sc_data_direction);
}
@@ -459,7 +466,7 @@
* Now get a new local CM ID so that we avoid confusing the
* target in case things are really fouled up.
*/
- new_cm_id = ib_create_cm_id(target->srp_host->dev,
+ new_cm_id = ib_create_cm_id(target->srp_host->dev->dev,
srp_cm_handler, target);
if (IS_ERR(new_cm_id)) {
ret = PTR_ERR(new_cm_id);
@@ -528,14 +535,79 @@
return ret;
}
+static int srp_map_fmr(struct srp_device *dev, struct scatterlist *scat,
+ int sg_cnt, struct srp_request *req,
+ struct srp_direct_buf *buf)
+{
+ u64 io_addr = 0;
+ u64 *dma_pages;
+ u32 len;
+ int page_cnt;
+ int i, j;
+ int ret;
+
+ if (!dev->fmr_pool)
+ return -ENODEV;
+
+ len = page_cnt = 0;
+ for (i = 0; i < sg_cnt; ++i) {
+ if (sg_dma_address(&scat[i]) & ~dev->fmr_page_mask) {
+ if (i > 0)
+ return -EINVAL;
+ else
+ ++page_cnt;
+ }
+ if ((sg_dma_address(&scat[i]) + sg_dma_len(&scat[i])) &
+ ~dev->fmr_page_mask) {
+ if (i < sg_cnt - 1)
+ return -EINVAL;
+ else
+ ++page_cnt;
+ }
+
+ len += sg_dma_len(&scat[i]);
+ }
+
+ page_cnt += len >> dev->fmr_page_shift;
+ if (page_cnt > SRP_FMR_SIZE)
+ return -ENOMEM;
+
+ dma_pages = kmalloc(sizeof (u64) * page_cnt, GFP_ATOMIC);
+ if (!dma_pages)
+ return -ENOMEM;
+
+ page_cnt = 0;
+ for (i = 0; i < sg_cnt; ++i)
+ for (j = 0; j < sg_dma_len(&scat[i]); j += dev->fmr_page_size)
+ dma_pages[page_cnt++] =
+ (sg_dma_address(&scat[i]) & dev->fmr_page_mask) + j;
+
+ req->fmr = ib_fmr_pool_map_phys(dev->fmr_pool,
+ dma_pages, page_cnt, &io_addr);
+ if (IS_ERR(req->fmr)) {
+ ret = PTR_ERR(req->fmr);
+ goto out;
+ }
+
+ buf->va = cpu_to_be64(sg_dma_address(&scat[0]) & ~dev->fmr_page_mask);
+ buf->key = cpu_to_be32(req->fmr->fmr->rkey);
+ buf->len = cpu_to_be32(len);
+
+ ret = 0;
+
+out:
+ kfree(dma_pages);
+
+ return ret;
+}
+
static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
struct srp_request *req)
{
struct scatterlist *scat;
struct srp_cmd *cmd = req->cmd->buf;
int len, nents, count;
- int i;
- u8 fmt;
+ u8 fmt = SRP_DATA_DESC_DIRECT;
if (!scmnd->request_buffer || scmnd->sc_data_direction == DMA_NONE)
return sizeof (struct srp_cmd);
@@ -560,53 +632,63 @@
sg_init_one(scat, scmnd->request_buffer, scmnd->request_bufflen);
}
- count = dma_map_sg(target->srp_host->dev->dma_device, scat, nents,
- scmnd->sc_data_direction);
+ count = dma_map_sg(target->srp_host->dev->dev->dma_device,
+ scat, nents, scmnd->sc_data_direction);
+
+ fmt = SRP_DATA_DESC_DIRECT;
+ len = sizeof (struct srp_cmd) + sizeof (struct srp_direct_buf);
if (count == 1) {
+ /*
+ * The midlayer only generated a single gather/scatter
+ * entry, or DMA mapping coalesced everything to a
+ * single entry. So a direct descriptor along with
+ * the DMA MR suffices.
+ */
struct srp_direct_buf *buf = (void *) cmd->add_data;
- fmt = SRP_DATA_DESC_DIRECT;
-
buf->va = cpu_to_be64(sg_dma_address(scat));
- buf->key = cpu_to_be32(target->srp_host->mr->rkey);
+ buf->key = cpu_to_be32(target->srp_host->dev->mr->rkey);
buf->len = cpu_to_be32(sg_dma_len(scat));
-
- len = sizeof (struct srp_cmd) +
- sizeof (struct srp_direct_buf);
- } else {
+ } else if (srp_map_fmr(target->srp_host->dev, scat, count, req,
+ (void *) cmd->add_data)) {
+ /*
+ * FMR mapping failed, and the scatterlist has more
+ * than one entry. Generate an indirect memory
+ * descriptor.
+ */
struct srp_indirect_buf *buf = (void *) cmd->add_data;
u32 datalen = 0;
+ int i;
fmt = SRP_DATA_DESC_INDIRECT;
+ len = sizeof (struct srp_cmd) +
+ sizeof (struct srp_indirect_buf) +
+ count * sizeof (struct srp_direct_buf);
+
+ for (i = 0; i < count; ++i) {
+ buf->desc_list[i].va =
+ cpu_to_be64(sg_dma_address(&scat[i]));
+ buf->desc_list[i].key =
+ cpu_to_be32(target->srp_host->dev->mr->rkey);
+ buf->desc_list[i].len =
+ cpu_to_be32(sg_dma_len(&scat[i]));
+ datalen += sg_dma_len(&scat[i]);
+ }
if (scmnd->sc_data_direction == DMA_TO_DEVICE)
cmd->data_out_desc_cnt = count;
else
cmd->data_in_desc_cnt = count;
- buf->table_desc.va = cpu_to_be64(req->cmd->dma +
- sizeof *cmd +
- sizeof *buf);
+ buf->table_desc.va =
+ cpu_to_be64(req->cmd->dma + sizeof *cmd + sizeof *buf);
buf->table_desc.key =
- cpu_to_be32(target->srp_host->mr->rkey);
+ cpu_to_be32(target->srp_host->dev->mr->rkey);
buf->table_desc.len =
cpu_to_be32(count * sizeof (struct srp_direct_buf));
- for (i = 0; i < count; ++i) {
- buf->desc_list[i].va = cpu_to_be64(sg_dma_address(&scat[i]));
- buf->desc_list[i].key =
- cpu_to_be32(target->srp_host->mr->rkey);
- buf->desc_list[i].len = cpu_to_be32(sg_dma_len(&scat[i]));
-
- datalen += sg_dma_len(&scat[i]);
- }
-
buf->len = cpu_to_be32(datalen);
-
- len = sizeof (struct srp_cmd) +
- sizeof (struct srp_indirect_buf) +
- count * sizeof (struct srp_direct_buf);
}
if (scmnd->sc_data_direction == DMA_TO_DEVICE)
@@ -689,7 +771,7 @@
iu = target->rx_ring[wc->wr_id & ~SRP_OP_RECV];
- dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
+ dma_sync_single_for_cpu(target->srp_host->dev->dev->dma_device, iu->dma,
target->max_ti_iu_len, DMA_FROM_DEVICE);
opcode = *(u8 *) iu->buf;
@@ -726,7 +808,7 @@
break;
}
- dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
+ dma_sync_single_for_device(target->srp_host->dev->dev->dma_device, iu->dma,
target->max_ti_iu_len, DMA_FROM_DEVICE);
}
@@ -770,7 +852,7 @@
list.addr = iu->dma;
list.length = iu->size;
- list.lkey = target->srp_host->mr->lkey;
+ list.lkey = target->srp_host->dev->mr->lkey;
wr.next = NULL;
wr.sg_list = &list;
@@ -828,7 +910,7 @@
list.addr = iu->dma;
list.length = len;
- list.lkey = target->srp_host->mr->lkey;
+ list.lkey = target->srp_host->dev->mr->lkey;
wr.next = NULL;
wr.wr_id = target->tx_head & SRP_SQ_SIZE;
@@ -870,7 +952,7 @@
if (!iu)
goto err;
- dma_sync_single_for_cpu(target->srp_host->dev->dma_device, iu->dma,
+ dma_sync_single_for_cpu(target->srp_host->dev->dev->dma_device, iu->dma,
SRP_MAX_IU_LEN, DMA_TO_DEVICE);
req = list_entry(target->free_reqs.next, struct srp_request, list);
@@ -903,7 +985,7 @@
goto err_unmap;
}
- dma_sync_single_for_device(target->srp_host->dev->dma_device, iu->dma,
+ dma_sync_single_for_device(target->srp_host->dev->dev->dma_device, iu->dma,
SRP_MAX_IU_LEN, DMA_TO_DEVICE);
if (__srp_post_send(target, iu, len)) {
@@ -1365,7 +1447,7 @@
sprintf(target->target_name, "SRP.T10:%016llX",
(unsigned long long) be64_to_cpu(target->id_ext));
- if (scsi_add_host(target->scsi_host, host->dev->dma_device))
+ if (scsi_add_host(target->scsi_host, host->dev->dev->dma_device))
return -ENODEV;
mutex_lock(&host->target_mutex);
@@ -1558,7 +1640,7 @@
if (ret)
goto err;
- ib_get_cached_gid(host->dev, host->port, 0, &target->path.sgid);
+ ib_get_cached_gid(host->dev->dev, host->port, 0, &target->path.sgid);
printk(KERN_DEBUG PFX "new target: id_ext %016llx ioc_guid %016llx pkey %04x "
"service_id %016llx dgid %04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
@@ -1579,7 +1661,7 @@
if (ret)
goto err;
- target->cm_id = ib_create_cm_id(host->dev, srp_cm_handler, target);
+ target->cm_id = ib_create_cm_id(host->dev->dev, srp_cm_handler, target);
if (IS_ERR(target->cm_id)) {
ret = PTR_ERR(target->cm_id);
goto err_free;
@@ -1619,7 +1701,7 @@
struct srp_host *host =
container_of(class_dev, struct srp_host, class_dev);
- return sprintf(buf, "%s\n", host->dev->name);
+ return sprintf(buf, "%s\n", host->dev->dev->name);
}
static CLASS_DEVICE_ATTR(ibdev, S_IRUGO, show_ibdev, NULL);
@@ -1634,7 +1716,7 @@
static CLASS_DEVICE_ATTR(port, S_IRUGO, show_port, NULL);
-static struct srp_host *srp_add_port(struct ib_device *device, u8 port)
+static struct srp_host *srp_add_port(struct srp_device *device, u8 port)
{
struct srp_host *host;
@@ -1649,26 +1731,15 @@
host->port = port;
host->initiator_port_id[7] = port;
- memcpy(host->initiator_port_id + 8, &device->node_guid, 8);
-
- host->pd = ib_alloc_pd(device);
- if (IS_ERR(host->pd))
- goto err_free;
-
- host->mr = ib_get_dma_mr(host->pd,
- IB_ACCESS_LOCAL_WRITE |
- IB_ACCESS_REMOTE_READ |
- IB_ACCESS_REMOTE_WRITE);
- if (IS_ERR(host->mr))
- goto err_pd;
+ memcpy(host->initiator_port_id + 8, &device->dev->node_guid, 8);
host->class_dev.class = &srp_class;
- host->class_dev.dev = device->dma_device;
+ host->class_dev.dev = device->dev->dma_device;
snprintf(host->class_dev.class_id, BUS_ID_SIZE, "srp-%s-%d",
- device->name, port);
+ device->dev->name, port);
if (class_device_register(&host->class_dev))
- goto err_mr;
+ goto free_host;
if (class_device_create_file(&host->class_dev, &class_device_attr_add_target))
goto err_class;
if (class_device_create_file(&host->class_dev, &class_device_attr_ibdev))
@@ -1681,13 +1752,7 @@
err_class:
class_device_unregister(&host->class_dev);
-err_mr:
- ib_dereg_mr(host->mr);
-
-err_pd:
- ib_dealloc_pd(host->pd);
-
-err_free:
+free_host:
kfree(host);
return NULL;
@@ -1695,15 +1760,62 @@
static void srp_add_one(struct ib_device *device)
{
- struct list_head *dev_list;
+ struct srp_device *srp_dev;
+ struct ib_device_attr *dev_attr;
+ struct ib_fmr_pool_param fmr_param;
struct srp_host *host;
int s, e, p;
- dev_list = kmalloc(sizeof *dev_list, GFP_KERNEL);
- if (!dev_list)
+ dev_attr = kmalloc(sizeof *dev_attr, GFP_KERNEL);
+ if (!dev_attr)
return;
- INIT_LIST_HEAD(dev_list);
+ if (ib_query_device(device, dev_attr)) {
+ printk(KERN_WARNING PFX "Query device failed for %s\n",
+ device->name);
+ goto free_attr;
+ }
+
+ srp_dev = kmalloc(sizeof *srp_dev, GFP_KERNEL);
+ if (!srp_dev)
+ goto free_attr;
+
+ /*
+ * Use the smallest page size supported by the HCA, down to a
+ * minimum of 512 bytes (which is the smallest sector that a
+ * SCSI command will ever carry).
+ */
+ srp_dev->fmr_page_shift = max(9, ffs(dev_attr->page_size_cap) - 1);
+ srp_dev->fmr_page_size = 1 << srp_dev->fmr_page_shift;
+ srp_dev->fmr_page_mask = ~((unsigned long) srp_dev->fmr_page_size - 1);
+
+ INIT_LIST_HEAD(&srp_dev->dev_list);
+
+ srp_dev->dev = device;
+ srp_dev->pd = ib_alloc_pd(device);
+ if (IS_ERR(srp_dev->pd))
+ goto free_dev;
+
+ srp_dev->mr = ib_get_dma_mr(srp_dev->pd,
+ IB_ACCESS_LOCAL_WRITE |
+ IB_ACCESS_REMOTE_READ |
+ IB_ACCESS_REMOTE_WRITE);
+ if (IS_ERR(srp_dev->mr))
+ goto err_pd;
+
+ memset(&fmr_param, 0, sizeof fmr_param);
+ fmr_param.pool_size = SRP_FMR_POOL_SIZE;
+ fmr_param.dirty_watermark = SRP_FMR_DIRTY_SIZE;
+ fmr_param.cache = 1;
+ fmr_param.max_pages_per_fmr = SRP_FMR_SIZE;
+ fmr_param.page_shift = srp_dev->fmr_page_shift;
+ fmr_param.access = (IB_ACCESS_LOCAL_WRITE |
+ IB_ACCESS_REMOTE_WRITE |
+ IB_ACCESS_REMOTE_READ);
+
+ srp_dev->fmr_pool = ib_create_fmr_pool(srp_dev->pd, &fmr_param);
+ if (IS_ERR(srp_dev->fmr_pool))
+ srp_dev->fmr_pool = NULL;
if (device->node_type == IB_NODE_SWITCH) {
s = 0;
@@ -1714,25 +1826,36 @@
}
for (p = s; p <= e; ++p) {
- host = srp_add_port(device, p);
+ host = srp_add_port(srp_dev, p);
if (host)
- list_add_tail(&host->list, dev_list);
+ list_add_tail(&host->list, &srp_dev->dev_list);
}
- ib_set_client_data(device, &srp_client, dev_list);
+ ib_set_client_data(device, &srp_client, srp_dev);
+
+ goto free_attr;
+
+err_pd:
+ ib_dealloc_pd(srp_dev->pd);
+
+free_dev:
+ kfree(srp_dev);
+
+free_attr:
+ kfree(dev_attr);
}
static void srp_remove_one(struct ib_device *device)
{
- struct list_head *dev_list;
+ struct srp_device *srp_dev;
struct srp_host *host, *tmp_host;
LIST_HEAD(target_list);
struct srp_target_port *target, *tmp_target;
unsigned long flags;
- dev_list = ib_get_client_data(device, &srp_client);
+ srp_dev = ib_get_client_data(device, &srp_client);
- list_for_each_entry_safe(host, tmp_host, dev_list, list) {
+ list_for_each_entry_safe(host, tmp_host, &srp_dev->dev_list, list) {
class_device_unregister(&host->class_dev);
/*
* Wait for the sysfs entry to go away, so that no new
@@ -1770,12 +1893,15 @@
scsi_host_put(target->scsi_host);
}
- ib_dereg_mr(host->mr);
- ib_dealloc_pd(host->pd);
kfree(host);
}
- kfree(dev_list);
+ if (srp_dev->fmr_pool)
+ ib_destroy_fmr_pool(srp_dev->fmr_pool);
+ ib_dereg_mr(srp_dev->mr);
+ ib_dealloc_pd(srp_dev->pd);
+
+ kfree(srp_dev);
}
static int __init srp_init_module(void)