描述：register stag for fast memory registration
static struct ib_mr *rxe_alloc_mr(struct ib_pd *ibpd, enum ib_mr_type mr_type, u32 max_num_sg, struct ib_udata *udata)
Value
Description
参数1
pd
ibv_alloc_pd ()返回的 pd
参数2
mr_type
指定类型IB_MR_TYPE_MEM_REG
参数3
max_num_sg
最大页数mem->max_buf
参数4
udata
元数据，在rxe_alloc_mr未使用
返回ok
struct ib_mr *
指向新分配的mr的指针
返回err
NULL
流程：
a) 将ib类型转换为rxe类型
b) 验证mr_type
c) 申请rxe_mem： mr = rxe_alloc(&rxe->mr_pool);
d) 为mr分配索引：rxe_add_index(mr)
e) 对对象进行引用：rxe_add_ref(pd)
f) 构成mr：rxe_mem_init_fast(pd, max_num_sg, mr);
1) int rxe_mem_init_fast(struct rxe_pd *pd,
int max_pages, struct rxe_mem *mem)
2) 初始化mr：rxe_mem_init(0, mem)->生成lkey和rkey
3) 申请mr：rxe_mem_alloc(mem, max_pages)->申请对应大小的mr
g) 返回新分配的mr
用户申请一块长度为len的虚拟内存，执行RDMA注册函数，将会得到一个映射表，包含两部分，
一个是sg_table记录着物理地址到pci域地址的转换关系，
另一个是VA->PA映射表，记录着VA到PA的转换关系。
调用链：在ib_create_qp()中使用
static inline struct ib_qp *ib_create_qp(struct ib_pd *pd,
struct ib_qp_init_attr *qp_init_attr)
{
return ib_create_qp_user(pd, qp_init_attr, NULL);
}
for user qp use ib_create_qp_user with valid udata：
struct ib_qp *ib_create_qp_user(struct ib_pd *pd,
struct ib_qp_init_attr *qp_init_attr,
struct ib_udata *udata);
在ib_creat_qp_user()中
if (qp_init_attr->cap.max_rdma_ctxs) {
ret = rdma_rw_init_mrs(qp, qp_init_attr);
if (ret)
goto err;
在rdma_rw_init_mrs()中-> ib_mr_pool_init()
int rdma_rw_init_mrs(struct ib_qp *qp, struct ib_qp_init_attr *attr)
{
u32 nr_mrs = 0, nr_sig_mrs = 0, max_num_sg = 0;
if (attr->create_flags & IB_QP_CREATE_INTEGRITY_EN) {
nr_sig_mrs = attr->cap.max_rdma_ctxs;
nr_mrs = attr->cap.max_rdma_ctxs;
max_num_sg = rdma_rw_fr_page_list_len(dev, true);
} else if (rdma_rw_can_use_mr(dev, attr->port_num)) {
nr_mrs = attr->cap.max_rdma_ctxs;
max_num_sg = rdma_rw_fr_page_list_len(dev, false);
if (nr_mrs) {
ret = ib_mr_pool_init(qp, &qp->rdma_mrs, nr_mrs,
IB_MR_TYPE_MEM_REG,
max_num_sg, 0);
if (ret) {
pr_err("%s: failed to allocated %d MRs\n",
__func__, nr_mrs);
return ret;
if (nr_sig_mrs) {
ret = ib_mr_pool_init(qp, &qp->sig_mrs, nr_sig_mrs,
IB_MR_TYPE_INTEGRITY, max_num_sg, max_num_sg);
if (ret) {
pr_err("%s: failed to allocated %d SIG MRs\n",
__func__, nr_sig_mrs);
goto out_free_rdma_mrs;
int ib_mr_pool_init(struct ib_qp *qp, struct list_head *list, int nr,
enum ib_mr_type type, u32 max_num_sg, u32 max_num_meta_sg)
{
for (i = 0; i < nr; i++) {
if (type == IB_MR_TYPE_INTEGRITY)
mr = ib_alloc_mr_integrity(qp->pd, max_num_sg,
max_num_meta_sg);
else
mr = ib_alloc_mr(qp->pd, type, max_num_sg);
}
static inline struct ib_mr *ib_alloc_mr(struct ib_pd *pd,
enum ib_mr_type mr_type, u32 max_num_sg)
{
return ib_alloc_mr_user(pd, mr_type, max_num_sg, NULL);
}
struct ib_mr *ib_alloc_mr_user(struct ib_pd *pd, enum ib_mr_type mr_type,u32 max_num_sg, struct ib_udata *udata)
{
mr = pd->device->ops.alloc_mr(pd, mr_type, max_num_sg, udata);
if (!IS_ERR(mr)) {
mr->device = pd->device;
mr->pd = pd;
mr->dm = NULL;
mr->uobject = NULL;
atomic_inc(&pd->usecnt);
mr->need_inval = false;
mr->res.type = RDMA_RESTRACK_MR;
rdma_restrack_kadd(&mr->res);
mr->type = mr_type;
mr->sig_attrs = NULL;
return mr;
}
在pd->device->ops.alloc_mr调用到.alloc_mr
总结：在申请QP的时候会使用到.alloc_mr，申请快速内存注册
Ops_rxe:
int rxe_mem_init_fast(struct rxe_pd *pd,
int max_pages, struct rxe_mem *mem)
{
int err;
rxe_mem_init(0, mem);
/* In fastreg, we also set the rkey */
mem->ibmr.rkey = mem->ibmr.lkey;
err = rxe_mem_alloc(mem, max_pages);
if (err)
goto err1;
mem->pd = pd;
mem->max_buf = max_pages;
mem->state = RXE_MEM_STATE_FREE;
mem->type = RXE_MEM_TYPE_MR;
return 0;
err1:
return err;
}
Ops_i40iw:
/**
* i40iw_alloc_mr - register stag for fast memory registration
* @pd: ibpd pointer
* @mr_type: memory for stag registrion
* @max_num_sg: man number of pages
* @udata: user data or NULL for kernel objects
*/
static struct ib_mr *i40iw_alloc_mr(struct ib_pd *pd, enum ib_mr_type mr_type,
u32 max_num_sg, struct ib_udata *udata)
{
struct i40iw_pd *iwpd = to_iwpd(pd);
struct i40iw_device *iwdev = to_iwdev(pd->device);
struct i40iw_pble_alloc *palloc;
struct i40iw_pbl *iwpbl;
struct i40iw_mr *iwmr;
enum i40iw_status_code status;
u32 stag;
int err_code = -ENOMEM;
iwmr = kzalloc(sizeof(*iwmr), GFP_KERNEL);
if (!iwmr)
return ERR_PTR(-ENOMEM);
stag = i40iw_create_stag(iwdev);
if (!stag) {
err_code = -EOVERFLOW;
goto err;
stag &= ~I40IW_CQPSQ_STAG_KEY_MASK;
iwmr->stag = stag;
iwmr->ibmr.rkey = stag;
iwmr->ibmr.lkey = stag;
iwmr->ibmr.pd = pd;
iwmr->ibmr.device = pd->device;
iwpbl = &iwmr->iwpbl;
iwpbl->iwmr = iwmr;
iwmr->type =
palloc = &iwpbl->pble_alloc;
iwmr->page_cnt = max_num_sg;
mutex_lock(&iwdev->pbl_mutex);
status = i40iw_get_pble(&iwdev->sc_dev, iwdev->pble_rsrc, palloc, iwmr->page_cnt);
mutex_unlock(&iwdev->pbl_mutex);
if (status)
goto err1;
if (palloc->level != I40IW_LEVEL_1)
goto err2;
err_code = i40iw_hw_alloc_stag(iwdev, iwmr);
if (err_code)
goto err2;
iwpbl->pbl_allocated = true;
i40iw_add_pdusecount(iwpd);
return &iwmr->ibmr;
err2:
i40iw_free_pble(iwdev->pble_rsrc, palloc);
err1:
i40iw_free_stag(iwdev, stag);
err:
kfree(iwmr);
return ERR_PTR(err_code);
}