mlx5_core: Add support for page faults events and low level handling

* Add a handler function pointer in the mlx5_core_qp struct for page
  fault events. Handle page fault events by calling the handler
  function, if not NULL.
* Add on-demand paging capability query command.
* Export command for resuming QPs after page faults.
* Add various constants related to paging support.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

3 files changed, 120 insertions, 1 deletions

diff --git a/include/linux/mlx5/device.h b/include/linux/mlx5/device.h
index 096abe543d2c..70c28239e339 100644
--- a/include/linux/mlx5/device.h
+++ b/include/linux/mlx5/device.h
@@ -120,6 +120,15 @@ enum {
 };
 
 enum {
+        MLX5_MKEY_INBOX_PG_ACCESS = 1 << 31
+};
+
+enum {
+        MLX5_PFAULT_SUBTYPE_WQE = 0,
+        MLX5_PFAULT_SUBTYPE_RDMA = 1,
+};
+
+enum {
         MLX5_PERM_LOCAL_READ    = 1 << 2,
         MLX5_PERM_LOCAL_WRITE   = 1 << 3,
         MLX5_PERM_REMOTE_READ   = 1 << 4,
@@ -215,6 +224,8 @@ enum mlx5_event {
 
         MLX5_EVENT_TYPE_CMD                = 0x0a,
         MLX5_EVENT_TYPE_PAGE_REQUEST       = 0xb,
+
+        MLX5_EVENT_TYPE_PAGE_FAULT         = 0xc,
 };
 
 enum {
@@ -300,6 +311,8 @@ enum {
 enum {
         HCA_CAP_OPMOD_GET_MAX   = 0,
         HCA_CAP_OPMOD_GET_CUR   = 1,
+        HCA_CAP_OPMOD_GET_ODP_MAX = 4,
+        HCA_CAP_OPMOD_GET_ODP_CUR = 5
 };
 
 struct mlx5_inbox_hdr {
@@ -329,6 +342,23 @@ struct mlx5_cmd_query_adapter_mbox_out {
         u8                      vsd_psid[16];
 };
 
+enum mlx5_odp_transport_cap_bits {
+        MLX5_ODP_SUPPORT_SEND    = 1 << 31,
+        MLX5_ODP_SUPPORT_RECV    = 1 << 30,
+        MLX5_ODP_SUPPORT_WRITE   = 1 << 29,
+        MLX5_ODP_SUPPORT_READ    = 1 << 28,
+};
+
+struct mlx5_odp_caps {
+        char reserved[0x10];
+        struct {
+                __be32                  rc_odp_caps;
+                __be32                  uc_odp_caps;
+                __be32                  ud_odp_caps;
+        } per_transport_caps;
+        char reserved2[0xe4];
+};
+
 struct mlx5_cmd_init_hca_mbox_in {
         struct mlx5_inbox_hdr   hdr;
         u8                      rsvd0[2];
@@ -449,6 +479,27 @@ struct mlx5_eqe_page_req {
         __be32          rsvd1[5];
 };
 
+struct mlx5_eqe_page_fault {
+        __be32 bytes_committed;
+        union {
+                struct {
+                        u16     reserved1;
+                        __be16  wqe_index;
+                        u16     reserved2;
+                        __be16  packet_length;
+                        u8      reserved3[12];
+                } __packed wqe;
+                struct {
+                        __be32  r_key;
+                        u16     reserved1;
+                        __be16  packet_length;
+                        __be32  rdma_op_len;
+                        __be64  rdma_va;
+                } __packed rdma;
+        } __packed;
+        __be32 flags_qpn;
+} __packed;
+
 union ev_data {
         __be32                          raw[7];
         struct mlx5_eqe_cmd             cmd;
@@ -460,6 +511,7 @@ union ev_data {
         struct mlx5_eqe_congestion      cong;
         struct mlx5_eqe_stall_vl        stall_vl;
         struct mlx5_eqe_page_req        req_pages;
+        struct mlx5_eqe_page_fault      page_fault;
 } __packed;
 
 struct mlx5_eqe {
@@ -826,7 +878,7 @@ struct mlx5_query_special_ctxs_mbox_out {
 struct mlx5_create_mkey_mbox_in {
         struct mlx5_inbox_hdr   hdr;
         __be32                  input_mkey_index;
-        u8                      rsvd0[4];
+        __be32                  flags;
         struct mlx5_mkey_seg    seg;
         u8                      rsvd1[16];
         __be32                  xlat_oct_act_size;
diff --git a/include/linux/mlx5/driver.h b/include/linux/mlx5/driver.h
index b1bf41556b32..7088dcd19214 100644
--- a/include/linux/mlx5/driver.h
+++ b/include/linux/mlx5/driver.h
@@ -113,6 +113,13 @@ enum {
         MLX5_REG_HOST_ENDIANNESS = 0x7004,
 };
 
+enum mlx5_page_fault_resume_flags {
+        MLX5_PAGE_FAULT_RESUME_REQUESTOR = 1 << 0,
+        MLX5_PAGE_FAULT_RESUME_WRITE     = 1 << 1,
+        MLX5_PAGE_FAULT_RESUME_RDMA      = 1 << 2,
+        MLX5_PAGE_FAULT_RESUME_ERROR     = 1 << 7,
+};
+
 enum dbg_rsc_type {
         MLX5_DBG_RSC_QP,
         MLX5_DBG_RSC_EQ,
@@ -703,6 +710,9 @@ void mlx5_eq_cleanup(struct mlx5_core_dev *dev);
 void mlx5_fill_page_array(struct mlx5_buf *buf, __be64 *pas);
 void mlx5_cq_completion(struct mlx5_core_dev *dev, u32 cqn);
 void mlx5_rsc_event(struct mlx5_core_dev *dev, u32 rsn, int event_type);
+#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
+void mlx5_eq_pagefault(struct mlx5_core_dev *dev, struct mlx5_eqe *eqe);
+#endif
 void mlx5_srq_event(struct mlx5_core_dev *dev, u32 srqn, int event_type);
 struct mlx5_core_srq *mlx5_core_get_srq(struct mlx5_core_dev *dev, u32 srqn);
 void mlx5_cmd_comp_handler(struct mlx5_core_dev *dev, unsigned long vector);
@@ -740,6 +750,8 @@ int mlx5_core_create_psv(struct mlx5_core_dev *dev, u32 pdn,
                          int npsvs, u32 *sig_index);
 int mlx5_core_destroy_psv(struct mlx5_core_dev *dev, int psv_num);
 void mlx5_core_put_rsc(struct mlx5_core_rsc_common *common);
+int mlx5_query_odp_caps(struct mlx5_core_dev *dev,
+                        struct mlx5_odp_caps *odp_caps);
 
 static inline u32 mlx5_mkey_to_idx(u32 mkey)
 {
diff --git a/include/linux/mlx5/qp.h b/include/linux/mlx5/qp.h
index 67f4b9660b06..6b1d6f60c7e6 100644
--- a/include/linux/mlx5/qp.h
+++ b/include/linux/mlx5/qp.h
@@ -50,6 +50,9 @@
 #define MLX5_BSF_APPTAG_ESCAPE  0x1
 #define MLX5_BSF_APPREF_ESCAPE  0x2
 
+#define MLX5_QPN_BITS           24
+#define MLX5_QPN_MASK           ((1 << MLX5_QPN_BITS) - 1)
+
 enum mlx5_qp_optpar {
         MLX5_QP_OPTPAR_ALT_ADDR_PATH            = 1 << 0,
         MLX5_QP_OPTPAR_RRE                      = 1 << 1,
@@ -363,9 +366,46 @@ struct mlx5_stride_block_ctrl_seg {
         __be16          num_entries;
 };
 
+enum mlx5_pagefault_flags {
+        MLX5_PFAULT_REQUESTOR = 1 << 0,
+        MLX5_PFAULT_WRITE     = 1 << 1,
+        MLX5_PFAULT_RDMA      = 1 << 2,
+};
+
+/* Contains the details of a pagefault. */
+struct mlx5_pagefault {
+        u32                     bytes_committed;
+        u8                      event_subtype;
+        enum mlx5_pagefault_flags flags;
+        union {
+                /* Initiator or send message responder pagefault details. */
+                struct {
+                        /* Received packet size, only valid for responders. */
+                        u32     packet_size;
+                        /*
+                         * WQE index. Refers to either the send queue or
+                         * receive queue, according to event_subtype.
+                         */
+                        u16     wqe_index;
+                } wqe;
+                /* RDMA responder pagefault details */
+                struct {
+                        u32     r_key;
+                        /*
+                         * Received packet size, minimal size page fault
+                         * resolution required for forward progress.
+                         */
+                        u32     packet_size;
+                        u32     rdma_op_len;
+                        u64     rdma_va;
+                } rdma;
+        };
+};
+
 struct mlx5_core_qp {
         struct mlx5_core_rsc_common     common; /* must be first */
         void (*event)           (struct mlx5_core_qp *, int);
+        void (*pfault_handler)(struct mlx5_core_qp *, struct mlx5_pagefault *);
         int                     qpn;
         struct mlx5_rsc_debug   *dbg;
         int                     pid;
@@ -533,6 +573,17 @@ static inline struct mlx5_core_mr *__mlx5_mr_lookup(struct mlx5_core_dev *dev, u
         return radix_tree_lookup(&dev->priv.mr_table.tree, key);
 }
 
+struct mlx5_page_fault_resume_mbox_in {
+        struct mlx5_inbox_hdr   hdr;
+        __be32                  flags_qpn;
+        u8                      reserved[4];
+};
+
+struct mlx5_page_fault_resume_mbox_out {
+        struct mlx5_outbox_hdr  hdr;
+        u8                      rsvd[8];
+};
+
 int mlx5_core_create_qp(struct mlx5_core_dev *dev,
                         struct mlx5_core_qp *qp,
                         struct mlx5_create_qp_mbox_in *in,
@@ -552,6 +603,10 @@ void mlx5_init_qp_table(struct mlx5_core_dev *dev);
 void mlx5_cleanup_qp_table(struct mlx5_core_dev *dev);
 int mlx5_debug_qp_add(struct mlx5_core_dev *dev, struct mlx5_core_qp *qp);
 void mlx5_debug_qp_remove(struct mlx5_core_dev *dev, struct mlx5_core_qp *qp);
+#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
+int mlx5_core_page_fault_resume(struct mlx5_core_dev *dev, u32 qpn,
+                                u8 context, int error);
+#endif
 
 static inline const char *mlx5_qp_type_str(int type)
 {