IB/mlx5: Move to fully dynamic UAR mode once user space supports it

Move to fully dynamic UAR mode once user space supports it.  In this case
we prevent any legacy mode of UARs on the allocated context and prevent
redundant allocation of the static ones.

Link: https://lore.kernel.org/r/20200324060143.1569116-6-leon@kernel.org
Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Reviewed-by: Michael Guralnik <michaelgur@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

4 files changed, 25 insertions, 3 deletions

diff --git a/drivers/infiniband/hw/mlx5/cq.c b/drivers/infiniband/hw/mlx5/cq.c
index 1d184bd5c759..f1c7fa561b16 100644
--- a/drivers/infiniband/hw/mlx5/cq.c
+++ b/drivers/infiniband/hw/mlx5/cq.c
@@ -741,10 +741,14 @@ static int create_cq_user(struct mlx5_ib_dev *dev, struct ib_udata *udata,
 	MLX5_SET(cqc, cqc, log_page_size,
 		 page_shift - MLX5_ADAPTER_PAGE_SHIFT);
 
-	if (ucmd.flags & MLX5_IB_CREATE_CQ_FLAGS_UAR_PAGE_INDEX)
+	if (ucmd.flags & MLX5_IB_CREATE_CQ_FLAGS_UAR_PAGE_INDEX) {
 		*index = ucmd.uar_page_index;
-	else
+	} else if (context->bfregi.lib_uar_dyn) {
+		err = -EINVAL;
+		goto err_cqb;
+	} else {
 		*index = context->bfregi.sys_pages[0];
+	}
 
 	if (ucmd.cqe_comp_en == 1) {
 		int mini_cqe_format;
diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 289445f6af21..12273851f2db 100644
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -1786,6 +1786,7 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 				     max_cqe_version);
 	u32 dump_fill_mkey;
 	bool lib_uar_4k;
+	bool lib_uar_dyn;
 
 	if (!dev->ib_active)
 		return -EAGAIN;
@@ -1844,8 +1845,14 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 	}
 
 	lib_uar_4k = req.lib_caps & MLX5_LIB_CAP_4K_UAR;
+	lib_uar_dyn = req.lib_caps & MLX5_LIB_CAP_DYN_UAR;
 	bfregi = &context->bfregi;
 
+	if (lib_uar_dyn) {
+		bfregi->lib_uar_dyn = lib_uar_dyn;
+		goto uar_done;
+	}
+
 	/* updates req->total_num_bfregs */
 	err = calc_total_bfregs(dev, lib_uar_4k, &req, bfregi);
 	if (err)
@@ -1872,6 +1879,7 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 	if (err)
 		goto out_sys_pages;
 
+uar_done:
 	if (req.flags & MLX5_IB_ALLOC_UCTX_DEVX) {
 		err = mlx5_ib_devx_create(dev, true);
 		if (err < 0)
@@ -1893,7 +1901,7 @@ static int mlx5_ib_alloc_ucontext(struct ib_ucontext *uctx,
 	INIT_LIST_HEAD(&context->db_page_list);
 	mutex_init(&context->db_page_mutex);
 
-	resp.tot_bfregs = req.total_num_bfregs;
+	resp.tot_bfregs = lib_uar_dyn ? 0 : req.total_num_bfregs;
 	resp.num_ports = dev->num_ports;
 
 	if (offsetofend(typeof(resp), cqe_version) <= udata->outlen)
@@ -2141,6 +2149,9 @@ static int uar_mmap(struct mlx5_ib_dev *dev, enum mlx5_ib_mmap_cmd cmd,
 	int max_valid_idx = dyn_uar ? bfregi->num_sys_pages :
 				bfregi->num_static_sys_pages;
 
+	if (bfregi->lib_uar_dyn)
+		return -EINVAL;
+
 	if (vma->vm_end - vma->vm_start != PAGE_SIZE)
 		return -EINVAL;
 
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index ae6289133cd8..b88414acb993 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -139,6 +139,7 @@ struct mlx5_bfreg_info {
 	struct mutex lock;
 	u32 ver;
 	u8 lib_uar_4k : 1;
+	u8 lib_uar_dyn : 1;
 	u32 num_sys_pages;
 	u32 num_static_sys_pages;
 	u32 total_num_bfregs;
diff --git a/drivers/infiniband/hw/mlx5/qp.c b/drivers/infiniband/hw/mlx5/qp.c
index b708a0484f77..aa7834d80493 100644
--- a/drivers/infiniband/hw/mlx5/qp.c
+++ b/drivers/infiniband/hw/mlx5/qp.c
@@ -697,6 +697,9 @@ static int alloc_bfreg(struct mlx5_ib_dev *dev,
 {
 	int bfregn = -ENOMEM;
 
+	if (bfregi->lib_uar_dyn)
+		return -EINVAL;
+
 	mutex_lock(&bfregi->lock);
 	if (bfregi->ver >= 2) {
 		bfregn = alloc_high_class_bfreg(dev, bfregi);
@@ -768,6 +771,9 @@ int bfregn_to_uar_index(struct mlx5_ib_dev *dev,
 	u32 index_of_sys_page;
 	u32 offset;
 
+	if (bfregi->lib_uar_dyn)
+		return -EINVAL;
+
 	bfregs_per_sys_page = get_uars_per_sys_page(dev, bfregi->lib_uar_4k) *
 				MLX5_NON_FP_BFREGS_PER_UAR;
 	index_of_sys_page = bfregn / bfregs_per_sys_page;