RDMA/mlx5: Refactor MR descriptors allocation

Improve code readability using static helpers for each memory region
type. Re-use the common logic to get smaller functions that are easy
to maintain and reduce code duplication.
Signed-off-by: Max Gurtovoy <maxg@mellanox.com>
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/mr.c

@@ -1651,80 +1651,63 @@ int mlx5_ib_dereg_mr(struct ib_mr *ibmr, struct ib_udata *udata)
 	return 0;
 }
 
-static struct mlx5_ib_mr *mlx5_ib_alloc_pi_mr(struct ib_pd *pd,
-				u32 max_num_sg, u32 max_num_meta_sg,
-				int desc_size, int access_mode)
+static void mlx5_set_umr_free_mkey(struct ib_pd *pd, u32 *in, int ndescs,
+				   int access_mode, int page_shift)
 {
-	struct mlx5_ib_dev *dev = to_mdev(pd->device);
-	int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
-	int ndescs = ALIGN(max_num_sg + max_num_meta_sg, 4);
-	struct mlx5_ib_mr *mr;
 	void *mkc;
-	u32 *in;
-	int err;
-
-	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
-	if (!mr)
-		return ERR_PTR(-ENOMEM);
-
-	in = kzalloc(inlen, GFP_KERNEL);
-	if (!in) {
-		err = -ENOMEM;
-		goto err_free;
-	}
 
 	mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
+
 	MLX5_SET(mkc, mkc, free, 1);
-	MLX5_SET(mkc, mkc, translations_octword_size, ndescs);
-	if (access_mode == MLX5_MKC_ACCESS_MODE_MTT)
-		MLX5_SET(mkc, mkc, log_page_size, PAGE_SHIFT);
 	MLX5_SET(mkc, mkc, qpn, 0xffffff);
 	MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);
+	MLX5_SET(mkc, mkc, translations_octword_size, ndescs);
+	MLX5_SET(mkc, mkc, access_mode_1_0, access_mode & 0x3);
+	MLX5_SET(mkc, mkc, access_mode_4_2, (access_mode >> 2) & 0x7);
+	MLX5_SET(mkc, mkc, umr_en, 1);
+	MLX5_SET(mkc, mkc, log_page_size, page_shift);
+}
+
+static int _mlx5_alloc_mkey_descs(struct ib_pd *pd, struct mlx5_ib_mr *mr,
+				  int ndescs, int desc_size, int page_shift,
+				  int access_mode, u32 *in, int inlen)
+{
+	struct mlx5_ib_dev *dev = to_mdev(pd->device);
+	int err;
 
 	mr->access_mode = access_mode;
+	mr->desc_size = desc_size;
+	mr->max_descs = ndescs;
 
 	err = mlx5_alloc_priv_descs(pd->device, mr, ndescs, desc_size);
 	if (err)
-		goto err_free_in;
-	mr->desc_size = desc_size;
-	mr->max_descs = ndescs;
+		return err;
 
-	MLX5_SET(mkc, mkc, access_mode_1_0, mr->access_mode & 0x3);
-	MLX5_SET(mkc, mkc, access_mode_4_2, (mr->access_mode >> 2) & 0x7);
-	MLX5_SET(mkc, mkc, umr_en, 1);
+	mlx5_set_umr_free_mkey(pd, in, ndescs, access_mode, page_shift);
 
-	mr->ibmr.pd = pd;
-	mr->ibmr.device = pd->device;
 	err = mlx5_core_create_mkey(dev->mdev, &mr->mmkey, in, inlen);
 	if (err)
-		goto err_priv_descs;
+		goto err_free_descs;
 
 	mr->mmkey.type = MLX5_MKEY_MR;
 	mr->ibmr.lkey = mr->mmkey.key;
 	mr->ibmr.rkey = mr->mmkey.key;
-	mr->umem = NULL;
-	kfree(in);
 
-	return mr;
+	return 0;
 
-err_priv_descs:
+err_free_descs:
 	mlx5_free_priv_descs(mr);
-err_free_in:
-	kfree(in);
-err_free:
-	kfree(mr);
-	return ERR_PTR(err);
+	return err;
 }
 
-static struct ib_mr *__mlx5_ib_alloc_mr(struct ib_pd *pd,
-					enum ib_mr_type mr_type, u32 max_num_sg,
-					u32 max_num_meta_sg)
+static struct mlx5_ib_mr *mlx5_ib_alloc_pi_mr(struct ib_pd *pd,
+				u32 max_num_sg, u32 max_num_meta_sg,
+				int desc_size, int access_mode)
 {
-	struct mlx5_ib_dev *dev = to_mdev(pd->device);
 	int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
-	int ndescs = ALIGN(max_num_sg, 4);
+	int ndescs = ALIGN(max_num_sg + max_num_meta_sg, 4);
+	int page_shift = 0;
 	struct mlx5_ib_mr *mr;
-	void *mkc;
 	u32 *in;
 	int err;
 
@@ -1732,57 +1715,68 @@ static struct ib_mr *__mlx5_ib_alloc_mr(struct ib_pd *pd,
 	if (!mr)
 		return ERR_PTR(-ENOMEM);
 
+	mr->ibmr.pd = pd;
+	mr->ibmr.device = pd->device;
+
 	in = kzalloc(inlen, GFP_KERNEL);
 	if (!in) {
 		err = -ENOMEM;
 		goto err_free;
 	}
 
-	mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
-	MLX5_SET(mkc, mkc, free, 1);
-	MLX5_SET(mkc, mkc, qpn, 0xffffff);
-	MLX5_SET(mkc, mkc, pd, to_mpd(pd)->pdn);
+	if (access_mode == MLX5_MKC_ACCESS_MODE_MTT)
+		page_shift = PAGE_SHIFT;
 
-	if (mr_type == IB_MR_TYPE_MEM_REG) {
-		mr->access_mode = MLX5_MKC_ACCESS_MODE_MTT;
-		MLX5_SET(mkc, mkc, translations_octword_size, ndescs);
-		MLX5_SET(mkc, mkc, log_page_size, PAGE_SHIFT);
-		err = mlx5_alloc_priv_descs(pd->device, mr,
-					    ndescs, sizeof(struct mlx5_mtt));
+	err = _mlx5_alloc_mkey_descs(pd, mr, ndescs, desc_size, page_shift,
+				     access_mode, in, inlen);
 	if (err)
 		goto err_free_in;
 
-		mr->desc_size = sizeof(struct mlx5_mtt);
-		mr->max_descs = ndescs;
-	} else if (mr_type == IB_MR_TYPE_SG_GAPS) {
-		mr->access_mode = MLX5_MKC_ACCESS_MODE_KLMS;
-		MLX5_SET(mkc, mkc, translations_octword_size, ndescs);
+	mr->umem = NULL;
+	kfree(in);
 
-		err = mlx5_alloc_priv_descs(pd->device, mr,
-					    ndescs, sizeof(struct mlx5_klm));
-		if (err)
-			goto err_free_in;
-		mr->desc_size = sizeof(struct mlx5_klm);
-		mr->max_descs = ndescs;
-	} else if (mr_type == IB_MR_TYPE_INTEGRITY) {
+	return mr;
+
+err_free_in:
+	kfree(in);
+err_free:
+	kfree(mr);
+	return ERR_PTR(err);
+}
+
+static int mlx5_alloc_mem_reg_descs(struct ib_pd *pd, struct mlx5_ib_mr *mr,
+				    int ndescs, u32 *in, int inlen)
+{
+	return _mlx5_alloc_mkey_descs(pd, mr, ndescs, sizeof(struct mlx5_mtt),
+				      PAGE_SHIFT, MLX5_MKC_ACCESS_MODE_MTT, in,
+				      inlen);
+}
+
+static int mlx5_alloc_sg_gaps_descs(struct ib_pd *pd, struct mlx5_ib_mr *mr,
+				    int ndescs, u32 *in, int inlen)
+{
+	return _mlx5_alloc_mkey_descs(pd, mr, ndescs, sizeof(struct mlx5_klm),
+				      0, MLX5_MKC_ACCESS_MODE_KLMS, in, inlen);
+}
+
+static int mlx5_alloc_integrity_descs(struct ib_pd *pd, struct mlx5_ib_mr *mr,
+				      int max_num_sg, int max_num_meta_sg,
+				      u32 *in, int inlen)
+{
+	struct mlx5_ib_dev *dev = to_mdev(pd->device);
 	u32 psv_index[2];
+	void *mkc;
+	int err;
 
-		MLX5_SET(mkc, mkc, bsf_en, 1);
-		MLX5_SET(mkc, mkc, bsf_octword_size, MLX5_MKEY_BSF_OCTO_SIZE);
-		MLX5_SET(mkc, mkc, translations_octword_size, 4);
 	mr->sig = kzalloc(sizeof(*mr->sig), GFP_KERNEL);
-		if (!mr->sig) {
-			err = -ENOMEM;
-			goto err_free_in;
-		}
+	if (!mr->sig)
+		return -ENOMEM;
 
 	/* create mem & wire PSVs */
-		err = mlx5_core_create_psv(dev->mdev, to_mpd(pd)->pdn,
-					   2, psv_index);
+	err = mlx5_core_create_psv(dev->mdev, to_mpd(pd)->pdn, 2, psv_index);
 	if (err)
 		goto err_free_sig;
 
-		mr->access_mode = MLX5_MKC_ACCESS_MODE_KLMS;
 	mr->sig->psv_memory.psv_idx = psv_index[0];
 	mr->sig->psv_wire.psv_idx = psv_index[1];
 
@@ -1790,69 +1784,99 @@ static struct ib_mr *__mlx5_ib_alloc_mr(struct ib_pd *pd,
 	mr->sig->sig_err_exists = false;
 	/* Next UMR, Arm SIGERR */
 	++mr->sig->sigerr_count;
-		mr->klm_mr = mlx5_ib_alloc_pi_mr(pd, max_num_sg,
-						max_num_meta_sg,
+	mr->klm_mr = mlx5_ib_alloc_pi_mr(pd, max_num_sg, max_num_meta_sg,
 					 sizeof(struct mlx5_klm),
 					 MLX5_MKC_ACCESS_MODE_KLMS);
 	if (IS_ERR(mr->klm_mr)) {
 		err = PTR_ERR(mr->klm_mr);
 		goto err_destroy_psv;
 	}
-		mr->mtt_mr = mlx5_ib_alloc_pi_mr(pd, max_num_sg,
-						max_num_meta_sg,
+	mr->mtt_mr = mlx5_ib_alloc_pi_mr(pd, max_num_sg, max_num_meta_sg,
 					 sizeof(struct mlx5_mtt),
 					 MLX5_MKC_ACCESS_MODE_MTT);
 	if (IS_ERR(mr->mtt_mr)) {
 		err = PTR_ERR(mr->mtt_mr);
 		goto err_free_klm_mr;
 	}
-	} else {
-		mlx5_ib_warn(dev, "Invalid mr type %d\n", mr_type);
-		err = -EINVAL;
-		goto err_free_in;
-	}
 
-	MLX5_SET(mkc, mkc, access_mode_1_0, mr->access_mode & 0x3);
-	MLX5_SET(mkc, mkc, access_mode_4_2, (mr->access_mode >> 2) & 0x7);
-	MLX5_SET(mkc, mkc, umr_en, 1);
+	/* Set bsf descriptors for mkey */
+	mkc = MLX5_ADDR_OF(create_mkey_in, in, memory_key_mkey_entry);
+	MLX5_SET(mkc, mkc, bsf_en, 1);
+	MLX5_SET(mkc, mkc, bsf_octword_size, MLX5_MKEY_BSF_OCTO_SIZE);
 
-	mr->ibmr.device = pd->device;
-	err = mlx5_core_create_mkey(dev->mdev, &mr->mmkey, in, inlen);
+	err = _mlx5_alloc_mkey_descs(pd, mr, 4, sizeof(struct mlx5_klm), 0,
+				     MLX5_MKC_ACCESS_MODE_KLMS, in, inlen);
 	if (err)
-		goto err_free_pi_mr;
+		goto err_free_mtt_mr;
 
-	mr->mmkey.type = MLX5_MKEY_MR;
-	mr->ibmr.lkey = mr->mmkey.key;
-	mr->ibmr.rkey = mr->mmkey.key;
-	mr->umem = NULL;
-	kfree(in);
-
-	return &mr->ibmr;
+	return 0;
 
-err_free_pi_mr:
-	if (mr->mtt_mr) {
+err_free_mtt_mr:
 	dereg_mr(to_mdev(mr->mtt_mr->ibmr.device), mr->mtt_mr);
 	mr->mtt_mr = NULL;
-	}
 err_free_klm_mr:
-	if (mr->klm_mr) {
 	dereg_mr(to_mdev(mr->klm_mr->ibmr.device), mr->klm_mr);
 	mr->klm_mr = NULL;
-	}
 err_destroy_psv:
-	if (mr->sig) {
-		if (mlx5_core_destroy_psv(dev->mdev,
-					  mr->sig->psv_memory.psv_idx))
+	if (mlx5_core_destroy_psv(dev->mdev, mr->sig->psv_memory.psv_idx))
 		mlx5_ib_warn(dev, "failed to destroy mem psv %d\n",
 			     mr->sig->psv_memory.psv_idx);
-		if (mlx5_core_destroy_psv(dev->mdev,
-					  mr->sig->psv_wire.psv_idx))
+	if (mlx5_core_destroy_psv(dev->mdev, mr->sig->psv_wire.psv_idx))
 		mlx5_ib_warn(dev, "failed to destroy wire psv %d\n",
 			     mr->sig->psv_wire.psv_idx);
-	}
-	mlx5_free_priv_descs(mr);
 err_free_sig:
 	kfree(mr->sig);
+
+	return err;
+}
+
+static struct ib_mr *__mlx5_ib_alloc_mr(struct ib_pd *pd,
+					enum ib_mr_type mr_type, u32 max_num_sg,
+					u32 max_num_meta_sg)
+{
+	struct mlx5_ib_dev *dev = to_mdev(pd->device);
+	int inlen = MLX5_ST_SZ_BYTES(create_mkey_in);
+	int ndescs = ALIGN(max_num_sg, 4);
+	struct mlx5_ib_mr *mr;
+	u32 *in;
+	int err;
+
+	mr = kzalloc(sizeof(*mr), GFP_KERNEL);
+	if (!mr)
+		return ERR_PTR(-ENOMEM);
+
+	in = kzalloc(inlen, GFP_KERNEL);
+	if (!in) {
+		err = -ENOMEM;
+		goto err_free;
+	}
+
+	mr->ibmr.device = pd->device;
+	mr->umem = NULL;
+
+	switch (mr_type) {
+	case IB_MR_TYPE_MEM_REG:
+		err = mlx5_alloc_mem_reg_descs(pd, mr, ndescs, in, inlen);
+		break;
+	case IB_MR_TYPE_SG_GAPS:
+		err = mlx5_alloc_sg_gaps_descs(pd, mr, ndescs, in, inlen);
+		break;
+	case IB_MR_TYPE_INTEGRITY:
+		err = mlx5_alloc_integrity_descs(pd, mr, max_num_sg,
+						 max_num_meta_sg, in, inlen);
+		break;
+	default:
+		mlx5_ib_warn(dev, "Invalid mr type %d\n", mr_type);
+		err = -EINVAL;
+	}
+
+	if (err)
+		goto err_free_in;
+
+	kfree(in);
+
+	return &mr->ibmr;
+
 err_free_in:
 	kfree(in);
 err_free: