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>
This commit is contained in:
Roland Dreier 2006-06-17 20:37:29 -07:00
parent a26026c122
commit f5358a172f
2 changed files with 228 additions and 87 deletions

View File

@ -105,7 +105,8 @@ static struct srp_iu *srp_alloc_iu(struct srp_host *host, size_t size,
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 @@ static void srp_free_iu(struct srp_host *host, struct srp_iu *iu)
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 @@ static int srp_init_qp(struct srp_target_port *target,
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 @@ static int srp_create_target_ib(struct srp_target_port *target)
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 @@ static int srp_create_target_ib(struct srp_target_port *target)
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 @@ static int srp_lookup_path(struct srp_target_port *target)
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 @@ static void srp_unmap_data(struct scsi_cmnd *scmnd,
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 @@ static void srp_unmap_data(struct scsi_cmnd *scmnd,
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 @@ static int srp_reconnect_target(struct srp_target_port *target)
* 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 @@ err:
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 @@ static int srp_map_data(struct scsi_cmnd *scmnd, struct srp_target_port *target,
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 @@ static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
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 @@ static void srp_handle_recv(struct srp_target_port *target, struct ib_wc *wc)
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 @@ static int __srp_post_recv(struct srp_target_port *target)
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 @@ static int __srp_post_send(struct srp_target_port *target,
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 @@ static int srp_queuecommand(struct scsi_cmnd *scmnd,
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 @@ static int srp_queuecommand(struct scsi_cmnd *scmnd,
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 @@ static int srp_add_target(struct srp_host *host, struct srp_target_port *target)
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 @@ static ssize_t srp_create_target(struct class_device *class_dev,
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 @@ static ssize_t srp_create_target(struct class_device *class_dev,
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 @@ static ssize_t show_ibdev(struct class_device *class_dev, char *buf)
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 ssize_t show_port(struct class_device *class_dev, char *buf)
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 @@ static struct srp_host *srp_add_port(struct ib_device *device, u8 port)
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 @@ static struct srp_host *srp_add_port(struct ib_device *device, u8 port)
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 @@ err_free:
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 @@ static void srp_add_one(struct ib_device *device)
}
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 @@ static void srp_remove_one(struct ib_device *device)
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)

View File

@ -46,6 +46,7 @@
#include <rdma/ib_verbs.h>
#include <rdma/ib_sa.h>
#include <rdma/ib_cm.h>
#include <rdma/ib_fmr_pool.h>
enum {
SRP_PATH_REC_TIMEOUT_MS = 1000,
@ -62,7 +63,11 @@ enum {
SRP_SQ_SIZE = SRP_RQ_SIZE - 1,
SRP_CQ_SIZE = SRP_SQ_SIZE + SRP_RQ_SIZE,
SRP_TAG_TSK_MGMT = 1 << (SRP_RQ_SHIFT + 1)
SRP_TAG_TSK_MGMT = 1 << (SRP_RQ_SHIFT + 1),
SRP_FMR_SIZE = 256,
SRP_FMR_POOL_SIZE = 1024,
SRP_FMR_DIRTY_SIZE = SRP_FMR_POOL_SIZE / 4
};
#define SRP_OP_RECV (1 << 31)
@ -77,15 +82,24 @@ enum srp_target_state {
SRP_TARGET_REMOVED
};
struct srp_host {
u8 initiator_port_id[16];
struct srp_device {
struct list_head dev_list;
struct ib_device *dev;
u8 port;
struct ib_pd *pd;
struct ib_mr *mr;
struct ib_fmr_pool *fmr_pool;
int fmr_page_shift;
int fmr_page_size;
unsigned long fmr_page_mask;
};
struct srp_host {
u8 initiator_port_id[16];
struct srp_device *dev;
u8 port;
struct class_device class_dev;
struct list_head target_list;
struct mutex target_mutex;
struct mutex target_mutex;
struct completion released;
struct list_head list;
};
@ -95,6 +109,7 @@ struct srp_request {
struct scsi_cmnd *scmnd;
struct srp_iu *cmd;
struct srp_iu *tsk_mgmt;
struct ib_pool_fmr *fmr;
/*
* Fake scatterlist used when scmnd->use_sg==0. Can be killed
* when the SCSI midlayer no longer generates non-SG commands.