IB/iser: Introduce fast memory registration model (FRWR)

Newer HCAs and Virtual functions may not support FMRs but rather a fast
registration model, which we call FRWR - "Fast Registration Work Requests".

This model was introduced in 00f7ec36c ("RDMA/core: Add memory management
extensions support") and works when the IB device supports the
IB_DEVICE_MEM_MGT_EXTENSIONS capability.

Upon creating the iser device iser will test whether the HCA supports
FMRs.  If no support for FMRs, check if IB_DEVICE_MEM_MGT_EXTENSIONS
is supported and assign function pointers that handle fast
registration and allocation of appropriate resources (fast_reg
descriptors).

Registration is done using posting IB_WR_FAST_REG_MR to the QP and
invalidations using posting IB_WR_LOCAL_INV.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
This commit is contained in:
Sagi Grimberg 2013-07-28 12:35:42 +03:00 committed by Roland Dreier
parent e657571b76
commit 5587856c96
3 changed files with 287 additions and 12 deletions

View File

@ -211,7 +211,7 @@ struct iser_mem_reg {
u64 va;
u64 len;
void *mem_h;
int is_fmr;
int is_mr;
};
struct iser_regd_buf {
@ -277,6 +277,15 @@ struct iser_device {
enum iser_data_dir cmd_dir);
};
struct fast_reg_descriptor {
struct list_head list;
/* For fast registration - FRWR */
struct ib_mr *data_mr;
struct ib_fast_reg_page_list *data_frpl;
/* Valid for fast registration flag */
bool valid;
};
struct iser_conn {
struct iscsi_iser_conn *iser_conn; /* iser conn for upcalls */
struct iscsi_endpoint *ep;
@ -307,6 +316,10 @@ struct iser_conn {
struct iser_page_vec *page_vec; /* represents SG to fmr maps*
* maps serialized as tx is*/
} fmr;
struct {
struct list_head pool;
int pool_size;
} frwr;
} fastreg;
};
@ -393,6 +406,8 @@ void iser_finalize_rdma_unaligned_sg(struct iscsi_iser_task *task,
int iser_reg_rdma_mem_fmr(struct iscsi_iser_task *task,
enum iser_data_dir cmd_dir);
int iser_reg_rdma_mem_frwr(struct iscsi_iser_task *task,
enum iser_data_dir cmd_dir);
int iser_connect(struct iser_conn *ib_conn,
struct sockaddr_in *src_addr,
@ -405,6 +420,8 @@ int iser_reg_page_vec(struct iser_conn *ib_conn,
void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
enum iser_data_dir cmd_dir);
void iser_unreg_mem_frwr(struct iscsi_iser_task *iser_task,
enum iser_data_dir cmd_dir);
int iser_post_recvl(struct iser_conn *ib_conn);
int iser_post_recvm(struct iser_conn *ib_conn, int count);
@ -421,4 +438,6 @@ int iser_initialize_task_headers(struct iscsi_task *task,
int iser_alloc_rx_descriptors(struct iser_conn *ib_conn, struct iscsi_session *session);
int iser_create_fmr_pool(struct iser_conn *ib_conn, unsigned cmds_max);
void iser_free_fmr_pool(struct iser_conn *ib_conn);
int iser_create_frwr_pool(struct iser_conn *ib_conn, unsigned cmds_max);
void iser_free_frwr_pool(struct iser_conn *ib_conn);
#endif

View File

@ -395,8 +395,7 @@ int iser_reg_rdma_mem_fmr(struct iscsi_iser_task *iser_task,
regd_buf = &iser_task->rdma_regd[cmd_dir];
aligned_len = iser_data_buf_aligned_len(mem, ibdev);
if (aligned_len != mem->dma_nents ||
(!ib_conn->fastreg.fmr.pool && mem->dma_nents > 1)) {
if (aligned_len != mem->dma_nents) {
err = fall_to_bounce_buf(iser_task, ibdev,
cmd_dir, aligned_len);
if (err) {
@ -414,7 +413,7 @@ int iser_reg_rdma_mem_fmr(struct iscsi_iser_task *iser_task,
regd_buf->reg.rkey = device->mr->rkey;
regd_buf->reg.len = ib_sg_dma_len(ibdev, &sg[0]);
regd_buf->reg.va = ib_sg_dma_address(ibdev, &sg[0]);
regd_buf->reg.is_fmr = 0;
regd_buf->reg.is_mr = 0;
iser_dbg("PHYSICAL Mem.register: lkey: 0x%08X rkey: 0x%08X "
"va: 0x%08lX sz: %ld]\n",
@ -444,3 +443,138 @@ int iser_reg_rdma_mem_fmr(struct iscsi_iser_task *iser_task,
}
return 0;
}
static int iser_fast_reg_mr(struct fast_reg_descriptor *desc,
struct iser_conn *ib_conn,
struct iser_regd_buf *regd_buf,
u32 offset, unsigned int data_size,
unsigned int page_list_len)
{
struct ib_send_wr fastreg_wr, inv_wr;
struct ib_send_wr *bad_wr, *wr = NULL;
u8 key;
int ret;
if (!desc->valid) {
memset(&inv_wr, 0, sizeof(inv_wr));
inv_wr.opcode = IB_WR_LOCAL_INV;
inv_wr.send_flags = IB_SEND_SIGNALED;
inv_wr.ex.invalidate_rkey = desc->data_mr->rkey;
wr = &inv_wr;
/* Bump the key */
key = (u8)(desc->data_mr->rkey & 0x000000FF);
ib_update_fast_reg_key(desc->data_mr, ++key);
}
/* Prepare FASTREG WR */
memset(&fastreg_wr, 0, sizeof(fastreg_wr));
fastreg_wr.opcode = IB_WR_FAST_REG_MR;
fastreg_wr.send_flags = IB_SEND_SIGNALED;
fastreg_wr.wr.fast_reg.iova_start = desc->data_frpl->page_list[0] + offset;
fastreg_wr.wr.fast_reg.page_list = desc->data_frpl;
fastreg_wr.wr.fast_reg.page_list_len = page_list_len;
fastreg_wr.wr.fast_reg.page_shift = SHIFT_4K;
fastreg_wr.wr.fast_reg.length = data_size;
fastreg_wr.wr.fast_reg.rkey = desc->data_mr->rkey;
fastreg_wr.wr.fast_reg.access_flags = (IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_WRITE |
IB_ACCESS_REMOTE_READ);
if (!wr) {
wr = &fastreg_wr;
atomic_inc(&ib_conn->post_send_buf_count);
} else {
wr->next = &fastreg_wr;
atomic_add(2, &ib_conn->post_send_buf_count);
}
ret = ib_post_send(ib_conn->qp, wr, &bad_wr);
if (ret) {
if (bad_wr->next)
atomic_sub(2, &ib_conn->post_send_buf_count);
else
atomic_dec(&ib_conn->post_send_buf_count);
iser_err("fast registration failed, ret:%d\n", ret);
return ret;
}
desc->valid = false;
regd_buf->reg.mem_h = desc;
regd_buf->reg.lkey = desc->data_mr->lkey;
regd_buf->reg.rkey = desc->data_mr->rkey;
regd_buf->reg.va = desc->data_frpl->page_list[0] + offset;
regd_buf->reg.len = data_size;
regd_buf->reg.is_mr = 1;
return ret;
}
/**
* iser_reg_rdma_mem_frwr - Registers memory intended for RDMA,
* using Fast Registration WR (if possible) obtaining rkey and va
*
* returns 0 on success, errno code on failure
*/
int iser_reg_rdma_mem_frwr(struct iscsi_iser_task *iser_task,
enum iser_data_dir cmd_dir)
{
struct iser_conn *ib_conn = iser_task->iser_conn->ib_conn;
struct iser_device *device = ib_conn->device;
struct ib_device *ibdev = device->ib_device;
struct iser_data_buf *mem = &iser_task->data[cmd_dir];
struct iser_regd_buf *regd_buf = &iser_task->rdma_regd[cmd_dir];
struct fast_reg_descriptor *desc;
unsigned int data_size, page_list_len;
int err, aligned_len;
unsigned long flags;
u32 offset;
aligned_len = iser_data_buf_aligned_len(mem, ibdev);
if (aligned_len != mem->dma_nents) {
err = fall_to_bounce_buf(iser_task, ibdev,
cmd_dir, aligned_len);
if (err) {
iser_err("failed to allocate bounce buffer\n");
return err;
}
mem = &iser_task->data_copy[cmd_dir];
}
/* if there a single dma entry, dma mr suffices */
if (mem->dma_nents == 1) {
struct scatterlist *sg = (struct scatterlist *)mem->buf;
regd_buf->reg.lkey = device->mr->lkey;
regd_buf->reg.rkey = device->mr->rkey;
regd_buf->reg.len = ib_sg_dma_len(ibdev, &sg[0]);
regd_buf->reg.va = ib_sg_dma_address(ibdev, &sg[0]);
regd_buf->reg.is_mr = 0;
} else {
spin_lock_irqsave(&ib_conn->lock, flags);
desc = list_first_entry(&ib_conn->fastreg.frwr.pool,
struct fast_reg_descriptor, list);
list_del(&desc->list);
spin_unlock_irqrestore(&ib_conn->lock, flags);
page_list_len = iser_sg_to_page_vec(mem, device->ib_device,
desc->data_frpl->page_list,
&offset, &data_size);
if (page_list_len * SIZE_4K < data_size) {
iser_err("fast reg page_list too short to hold this SG\n");
err = -EINVAL;
goto err_reg;
}
err = iser_fast_reg_mr(desc, ib_conn, regd_buf,
offset, data_size, page_list_len);
if (err)
goto err_reg;
}
return 0;
err_reg:
spin_lock_irqsave(&ib_conn->lock, flags);
list_add_tail(&desc->list, &ib_conn->fastreg.frwr.pool);
spin_unlock_irqrestore(&ib_conn->lock, flags);
return err;
}

View File

@ -73,12 +73,36 @@ static int iser_create_device_ib_res(struct iser_device *device)
{
int i, j;
struct iser_cq_desc *cq_desc;
struct ib_device_attr *dev_attr;
/* Assign function handles */
device->iser_alloc_rdma_reg_res = iser_create_fmr_pool;
device->iser_free_rdma_reg_res = iser_free_fmr_pool;
device->iser_reg_rdma_mem = iser_reg_rdma_mem_fmr;
device->iser_unreg_rdma_mem = iser_unreg_mem_fmr;
dev_attr = kmalloc(sizeof(*dev_attr), GFP_KERNEL);
if (!dev_attr)
return -ENOMEM;
if (ib_query_device(device->ib_device, dev_attr)) {
pr_warn("Query device failed for %s\n", device->ib_device->name);
goto dev_attr_err;
}
/* Assign function handles - based on FMR support */
if (device->ib_device->alloc_fmr && device->ib_device->dealloc_fmr &&
device->ib_device->map_phys_fmr && device->ib_device->unmap_fmr) {
iser_info("FMR supported, using FMR for registration\n");
device->iser_alloc_rdma_reg_res = iser_create_fmr_pool;
device->iser_free_rdma_reg_res = iser_free_fmr_pool;
device->iser_reg_rdma_mem = iser_reg_rdma_mem_fmr;
device->iser_unreg_rdma_mem = iser_unreg_mem_fmr;
} else
if (dev_attr->device_cap_flags & IB_DEVICE_MEM_MGT_EXTENSIONS) {
iser_info("FRWR supported, using FRWR for registration\n");
device->iser_alloc_rdma_reg_res = iser_create_frwr_pool;
device->iser_free_rdma_reg_res = iser_free_frwr_pool;
device->iser_reg_rdma_mem = iser_reg_rdma_mem_frwr;
device->iser_unreg_rdma_mem = iser_unreg_mem_frwr;
} else {
iser_err("IB device does not support FMRs nor FRWRs, can't register memory\n");
goto dev_attr_err;
}
device->cqs_used = min(ISER_MAX_CQ, device->ib_device->num_comp_vectors);
iser_info("using %d CQs, device %s supports %d vectors\n",
@ -134,6 +158,7 @@ static int iser_create_device_ib_res(struct iser_device *device)
if (ib_register_event_handler(&device->event_handler))
goto handler_err;
kfree(dev_attr);
return 0;
handler_err:
@ -153,6 +178,8 @@ pd_err:
kfree(device->cq_desc);
cq_desc_err:
iser_err("failed to allocate an IB resource\n");
dev_attr_err:
kfree(dev_attr);
return -1;
}
@ -252,6 +279,80 @@ void iser_free_fmr_pool(struct iser_conn *ib_conn)
ib_conn->fastreg.fmr.page_vec = NULL;
}
/**
* iser_create_frwr_pool - Creates pool of fast_reg descriptors
* for fast registration work requests.
* returns 0 on success, or errno code on failure
*/
int iser_create_frwr_pool(struct iser_conn *ib_conn, unsigned cmds_max)
{
struct iser_device *device = ib_conn->device;
struct fast_reg_descriptor *desc;
int i, ret;
INIT_LIST_HEAD(&ib_conn->fastreg.frwr.pool);
ib_conn->fastreg.frwr.pool_size = 0;
for (i = 0; i < cmds_max; i++) {
desc = kmalloc(sizeof(*desc), GFP_KERNEL);
if (!desc) {
iser_err("Failed to allocate a new fast_reg descriptor\n");
ret = -ENOMEM;
goto err;
}
desc->data_frpl = ib_alloc_fast_reg_page_list(device->ib_device,
ISCSI_ISER_SG_TABLESIZE + 1);
if (IS_ERR(desc->data_frpl)) {
ret = PTR_ERR(desc->data_frpl);
iser_err("Failed to allocate ib_fast_reg_page_list err=%d\n", ret);
goto err;
}
desc->data_mr = ib_alloc_fast_reg_mr(device->pd,
ISCSI_ISER_SG_TABLESIZE + 1);
if (IS_ERR(desc->data_mr)) {
ret = PTR_ERR(desc->data_mr);
iser_err("Failed to allocate ib_fast_reg_mr err=%d\n", ret);
ib_free_fast_reg_page_list(desc->data_frpl);
goto err;
}
desc->valid = true;
list_add_tail(&desc->list, &ib_conn->fastreg.frwr.pool);
ib_conn->fastreg.frwr.pool_size++;
}
return 0;
err:
iser_free_frwr_pool(ib_conn);
return ret;
}
/**
* iser_free_frwr_pool - releases the pool of fast_reg descriptors
*/
void iser_free_frwr_pool(struct iser_conn *ib_conn)
{
struct fast_reg_descriptor *desc, *tmp;
int i = 0;
if (list_empty(&ib_conn->fastreg.frwr.pool))
return;
iser_info("freeing conn %p frwr pool\n", ib_conn);
list_for_each_entry_safe(desc, tmp, &ib_conn->fastreg.frwr.pool, list) {
list_del(&desc->list);
ib_free_fast_reg_page_list(desc->data_frpl);
ib_dereg_mr(desc->data_mr);
kfree(desc);
++i;
}
if (i < ib_conn->fastreg.frwr.pool_size)
iser_warn("pool still has %d regions registered\n",
ib_conn->fastreg.frwr.pool_size - i);
}
/**
* iser_create_ib_conn_res - Queue-Pair (QP)
*
@ -707,7 +808,7 @@ int iser_reg_page_vec(struct iser_conn *ib_conn,
mem_reg->rkey = mem->fmr->rkey;
mem_reg->len = page_vec->length * SIZE_4K;
mem_reg->va = io_addr;
mem_reg->is_fmr = 1;
mem_reg->is_mr = 1;
mem_reg->mem_h = (void *)mem;
mem_reg->va += page_vec->offset;
@ -734,7 +835,7 @@ void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
int ret;
if (!reg->is_fmr)
if (!reg->is_mr)
return;
iser_dbg("PHYSICAL Mem.Unregister mem_h %p\n",reg->mem_h);
@ -746,6 +847,23 @@ void iser_unreg_mem_fmr(struct iscsi_iser_task *iser_task,
reg->mem_h = NULL;
}
void iser_unreg_mem_frwr(struct iscsi_iser_task *iser_task,
enum iser_data_dir cmd_dir)
{
struct iser_mem_reg *reg = &iser_task->rdma_regd[cmd_dir].reg;
struct iser_conn *ib_conn = iser_task->iser_conn->ib_conn;
struct fast_reg_descriptor *desc = reg->mem_h;
if (!reg->is_mr)
return;
reg->mem_h = NULL;
reg->is_mr = 0;
spin_lock_bh(&ib_conn->lock);
list_add_tail(&desc->list, &ib_conn->fastreg.frwr.pool);
spin_unlock_bh(&ib_conn->lock);
}
int iser_post_recvl(struct iser_conn *ib_conn)
{
struct ib_recv_wr rx_wr, *rx_wr_failed;
@ -867,7 +985,11 @@ static int iser_drain_tx_cq(struct iser_device *device, int cq_index)
if (wc.status == IB_WC_SUCCESS) {
if (wc.opcode == IB_WC_SEND)
iser_snd_completion(tx_desc, ib_conn);
else
else if (wc.opcode == IB_WC_LOCAL_INV ||
wc.opcode == IB_WC_FAST_REG_MR) {
atomic_dec(&ib_conn->post_send_buf_count);
continue;
} else
iser_err("expected opcode %d got %d\n",
IB_WC_SEND, wc.opcode);
} else {