bnxt_re/lib: Add uverbs object handle path for CQ/SRQ toggle page

The kernel driver supports two paths for the GET_TOGGLE_MEM ioctl:

- Legacy path (older kernels / older rdma-core): the caller sends
  BNXT_RE_TOGGLE_MEM_TYPE (enum: CQ or SRQ) and BNXT_RE_TOGGLE_MEM_RES_ID
  (the hardware queue ID). The kernel performs an XArray lookup per
  ucontext to find the toggle page.

- New path (new kernel + new rdma-core): the caller sends a uverbs
  object handle (BNXT_RE_TOGGLE_MEM_CQ_HANDLE or
  BNXT_RE_TOGGLE_MEM_SRQ_HANDLE). The kernel resolves the uobject
  directly, with built-in ownership verification and pinning.

During alloc_ucontext, lib  now sets the new request bit
BNXT_RE_COMP_MASK_REQ_UCNTX_TOGGLE_MEM_UOBJ_SUPPORT to advertise
uobj-handle capability. If the kernel responds with
BNXT_RE_UCNTX_CMASK_TOGGLE_MEM_UOBJ_SUPPORT. Based on the negotiated
capability, new path will be selected.

Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>

Author: selvintxavier

providers/bnxt_re/bnxt_re-abi.h

@@ -229,6 +229,7 @@ enum {
 	BNXT_RE_COMP_MASK_UCNTX_POW2_DISABLED = 0x04,
 	BNXT_RE_COMP_MASK_UCNTX_MSN_TABLE_ENABLED = 0x08,
 	BNXT_RE_COMP_MASK_UCNTX_RATE_LIMIT_ENABLED = 0x10,
+	BNXT_RE_COMP_MASK_UCNTX_TOGGLE_MEM_UOBJ_SUPPORT = 0x20,
 };
 
 enum bnxt_re_que_flags_mask {

providers/bnxt_re/main.c

@@ -200,6 +200,7 @@ static struct verbs_context *bnxt_re_alloc_context(struct ibv_device *vdev,
 
 	req.comp_mask |= BNXT_RE_COMP_MASK_REQ_UCNTX_POW2_SUPPORT;
 	req.comp_mask |= BNXT_RE_COMP_MASK_REQ_UCNTX_VAR_WQE_SUPPORT;
+	req.comp_mask |= BNXT_RE_COMP_MASK_REQ_UCNTX_TOGGLE_MEM_UOBJ_SUPPORT;
 	if (ibv_cmd_get_context(&cntx->ibvctx, &req.ibv_cmd, sizeof(req),
 				NULL, &resp.ibv_resp, sizeof(resp)))
 		goto failed;
@@ -231,7 +232,8 @@ static struct verbs_context *bnxt_re_alloc_context(struct ibv_device *vdev,
 		cntx->comp_mask |= BNXT_RE_COMP_MASK_UCNTX_MSN_TABLE_ENABLED;
 	if (resp.comp_mask & BNXT_RE_UCNTX_CMASK_QP_RATE_LIMIT_ENABLED)
 		cntx->comp_mask |= BNXT_RE_COMP_MASK_UCNTX_RATE_LIMIT_ENABLED;
-
+	if (resp.comp_mask & BNXT_RE_UCNTX_CMASK_TOGGLE_MEM_UOBJ_SUPPORT)
+		cntx->comp_mask |= BNXT_RE_COMP_MASK_UCNTX_TOGGLE_MEM_UOBJ_SUPPORT;
 	/* mmap shared page. */
 	cntx->shpg = mmap(NULL, rdev->pg_size, PROT_READ | PROT_WRITE,
 			  MAP_SHARED, cmd_fd, 0);

providers/bnxt_re/main.h

@@ -283,7 +283,7 @@ struct bnxt_re_pacing_data {
 };
 
 struct bnxt_re_mmap_info {
-	__u32 type;
+	enum bnxt_re_get_toggle_mem_type type;
 	__u32 dpi;
 	__u64 alloc_offset;
 	__u32 alloc_size;
@@ -319,6 +319,7 @@ int bnxt_re_alloc_page(struct ibv_context *ibvctx,
 int bnxt_re_notify_drv(struct ibv_context *ibvctx);
 int bnxt_re_get_toggle_mem(struct ibv_context *ibvctx,
 			   struct bnxt_re_mmap_info *minfo,
+			   uint32_t obj_handle,
 			   uint32_t *page_handle);
 
 /* pointer conversion functions*/
@@ -637,4 +638,6 @@ static inline void bnxt_re_sub_sec_busy_wait(uint32_t nsec)
 
 #define BNXT_RE_MSN_TBL_EN(a) ((a)->comp_mask & BNXT_RE_COMP_MASK_UCNTX_MSN_TABLE_ENABLED)
 #define BNXT_RE_RATE_LIMIT_EN(a) ((a)->comp_mask & BNXT_RE_COMP_MASK_UCNTX_RATE_LIMIT_ENABLED)
+#define BNXT_RE_TOGGLE_MEM_UOBJ_EN(a) \
+	((a)->comp_mask & BNXT_RE_COMP_MASK_UCNTX_TOGGLE_MEM_UOBJ_SUPPORT)
 #endif

providers/bnxt_re/verbs.c

@@ -117,8 +117,10 @@ static int bnxt_re_map_db_page(struct ibv_context *ibvctx,
 
 int bnxt_re_get_toggle_mem(struct ibv_context *ibvctx,
 			   struct bnxt_re_mmap_info *minfo,
+			   uint32_t obj_handle,
 			   uint32_t *page_handle)
 {
+	struct bnxt_re_context *cntx = to_bnxt_re_context(ibvctx);
 	DECLARE_COMMAND_BUFFER(cmd,
 			       BNXT_RE_OBJECT_GET_TOGGLE_MEM,
 			       BNXT_RE_METHOD_GET_TOGGLE_MEM,
@@ -127,15 +129,21 @@ int bnxt_re_get_toggle_mem(struct ibv_context *ibvctx,
 	int ret;
 
 	handle = fill_attr_out_obj(cmd, BNXT_RE_TOGGLE_MEM_HANDLE);
-	fill_attr_const_in(cmd, BNXT_RE_TOGGLE_MEM_TYPE, minfo->type);
-	fill_attr_in(cmd, BNXT_RE_TOGGLE_MEM_RES_ID, &minfo->res_id, sizeof(minfo->res_id));
-	fill_attr_out_ptr(cmd, BNXT_RE_TOGGLE_MEM_MMAP_PAGE,  &minfo->alloc_offset);
+	if (BNXT_RE_TOGGLE_MEM_UOBJ_EN(cntx)) {
+		if (minfo->type == BNXT_RE_CQ_TOGGLE_MEM)
+			fill_attr_in_obj(cmd, BNXT_RE_TOGGLE_MEM_CQ_HANDLE, obj_handle);
+		else
+			fill_attr_in_obj(cmd, BNXT_RE_TOGGLE_MEM_SRQ_HANDLE, obj_handle);
+	} else {
+		fill_attr_const_in(cmd, BNXT_RE_TOGGLE_MEM_TYPE, minfo->type);
+		fill_attr_in(cmd, BNXT_RE_TOGGLE_MEM_RES_ID,
+			     &minfo->res_id, sizeof(minfo->res_id));
+	}
+	fill_attr_out_ptr(cmd, BNXT_RE_TOGGLE_MEM_MMAP_PAGE, &minfo->alloc_offset);
 	fill_attr_out_ptr(cmd, BNXT_RE_TOGGLE_MEM_MMAP_LENGTH, &minfo->alloc_size);
 	fill_attr_out_ptr(cmd, BNXT_RE_TOGGLE_MEM_MMAP_OFFSET, &minfo->pg_offset);
 
-
 	ret = execute_ioctl(ibvctx, cmd);
-
 	if (ret)
 		return ret;
 	if (page_handle)
@@ -389,10 +397,10 @@ struct ibv_cq *bnxt_re_create_cq(struct ibv_context *ibvctx, int ncqe,
 	cq->rand.seed = cq->cqid;
 
 	if (resp.comp_mask & BNXT_RE_CQ_TOGGLE_PAGE_SUPPORT) {
-
 		minfo.type = BNXT_RE_CQ_TOGGLE_MEM;
 		minfo.res_id = resp.cqid;
-		ret = bnxt_re_get_toggle_mem(ibvctx, &minfo, &cq->mem_handle);
+		ret = bnxt_re_get_toggle_mem(ibvctx, &minfo, cq->ibvcq.handle,
+					     &cq->mem_handle);
 		if (ret)
 			goto cmdfail;
 		cq->toggle_map = mmap(NULL, minfo.alloc_size, PROT_READ,
@@ -2843,7 +2851,8 @@ struct ibv_srq *bnxt_re_create_srq(struct ibv_pd *ibvpd,
 	if (resp.comp_mask & BNXT_RE_SRQ_TOGGLE_PAGE_SUPPORT) {
 		minfo.type = BNXT_RE_SRQ_TOGGLE_MEM;
 		minfo.res_id = resp.srqid;
-		ret = bnxt_re_get_toggle_mem(ibvpd->context, &minfo, &srq->mem_handle);
+		ret = bnxt_re_get_toggle_mem(ibvpd->context, &minfo,
+					     srq->ibvsrq.handle, &srq->mem_handle);
 		if (ret)
 			goto fail;
 		srq->toggle_map = mmap(NULL, minfo.alloc_size, PROT_READ,