IB/core: Introduce signature verbs API

Introduce a verbs interface for signature-related operations.  A
signature handover operation configures the layouts of data and
protection attributes both in memory and wire domains.

Signature operations are:

- INSERT:
  Generate and insert protection information when handing over
  data from input space to output space.
- validate and STRIP:
  Validate protection information and remove it when handing over
  data from input space to output space.
- validate and PASS:
  Validate protection information and pass it when handing over
  data from input space to output space.

Once the signature handover opration is done, the HCA will offload
data integrity generation/validation while performing the actual data
transfer.

Additions:

1. HCA signature capabilities in device attributes
    Verbs provider supporting signature handover operations fills
    relevant fields in device attributes structure returned by
    ib_query_device.

2. QP creation flag IB_QP_CREATE_SIGNATURE_EN
    Creating a QP that will carry signature handover operations may
    require some special preparations from the verbs provider.  So we
    add QP creation flag IB_QP_CREATE_SIGNATURE_EN to declare that the
    created QP may carry out signature handover operations.  Expose
    signature support to verbs layer (no support for now).

3. New send work request IB_WR_REG_SIG_MR
    Signature handover work request. This WR will define the signature
    handover properties of the memory/wire domains as well as the
    domains layout. The purpose of this work request is to bind all
    the needed information for the signature operation:

    - data to be transferred:  wr->sg_list (ib_sge).
      * The raw data, pre-registered to a single MR (normally, before
        signature, this MR would have been used directly for the data
        transfer)
    - data protection guards: sig_handover.prot (ib_sge).
      * The data protection buffer, pre-registered to a single MR, which
        contains the data integrity guards of the raw data blocks.
        Note that it may not always exist, only in cases where the user is
        interested in storing protection guards in memory.
    - signature operation attributes: sig_handover.sig_attrs.
      * Tells the HCA how to validate/generate the protection information.

    Once the work request is executed, the memory region that will
    describe the signature transaction will be the sig_mr.  The
    application can now go ahead and send the sig_mr.rkey or use the
    sig_mr.lkey for data transfer.

4. New Verb ib_check_mr_status
    check_mr_status verb checks the status of the memory region post
    transaction.  The first check that may be used is
    IB_MR_CHECK_SIG_STATUS, which will indicate if any signature
    errors are pending for a specific signature-enabled ib_mr.  This
    verb is a lightwight check and is allowed to be taken from
    interrupt context.  An application must call this verb after it is
    known that the actual data transfer has finished.
Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/core/verbs.c

@@ -1437,3 +1437,11 @@ int ib_destroy_flow(struct ib_flow *flow_id)
 	return err;
 }
 EXPORT_SYMBOL(ib_destroy_flow);
+
+int ib_check_mr_status(struct ib_mr *mr, u32 check_mask,
+		       struct ib_mr_status *mr_status)
+{
+	return mr->device->check_mr_status ?
+		mr->device->check_mr_status(mr, check_mask, mr_status) : -ENOSYS;
+}
+EXPORT_SYMBOL(ib_check_mr_status);

include/rdma/ib_verbs.h

@@ -122,7 +122,19 @@ enum ib_device_cap_flags {
 	IB_DEVICE_BLOCK_MULTICAST_LOOPBACK = (1<<22),
 	IB_DEVICE_MEM_WINDOW_TYPE_2A	= (1<<23),
 	IB_DEVICE_MEM_WINDOW_TYPE_2B	= (1<<24),
-	IB_DEVICE_MANAGED_FLOW_STEERING = (1<<29)
+	IB_DEVICE_MANAGED_FLOW_STEERING = (1<<29),
+	IB_DEVICE_SIGNATURE_HANDOVER	= (1<<30)
+};
+
+enum ib_signature_prot_cap {
+	IB_PROT_T10DIF_TYPE_1 = 1,
+	IB_PROT_T10DIF_TYPE_2 = 1 << 1,
+	IB_PROT_T10DIF_TYPE_3 = 1 << 2,
+};
+
+enum ib_signature_guard_cap {
+	IB_GUARD_T10DIF_CRC	= 1,
+	IB_GUARD_T10DIF_CSUM	= 1 << 1,
 };
 
 enum ib_atomic_cap {
@@ -172,6 +184,8 @@ struct ib_device_attr {
 	unsigned int		max_fast_reg_page_list_len;
 	u16			max_pkeys;
 	u8			local_ca_ack_delay;
+	int			sig_prot_cap;
+	int			sig_guard_cap;
 };
 
 enum ib_mtu {
@@ -477,6 +491,114 @@ struct ib_mr_init_attr {
 	u32	    flags;
 };
 
+enum ib_signature_type {
+	IB_SIG_TYPE_T10_DIF,
+};
+
+/**
+ * T10-DIF Signature types
+ * T10-DIF types are defined by SCSI
+ * specifications.
+ */
+enum ib_t10_dif_type {
+	IB_T10DIF_NONE,
+	IB_T10DIF_TYPE1,
+	IB_T10DIF_TYPE2,
+	IB_T10DIF_TYPE3
+};
+
+/**
+ * Signature T10-DIF block-guard types
+ * IB_T10DIF_CRC: Corresponds to T10-PI mandated CRC checksum rules.
+ * IB_T10DIF_CSUM: Corresponds to IP checksum rules.
+ */
+enum ib_t10_dif_bg_type {
+	IB_T10DIF_CRC,
+	IB_T10DIF_CSUM
+};
+
+/**
+ * struct ib_t10_dif_domain - Parameters specific for T10-DIF
+ *     domain.
+ * @type: T10-DIF type (0|1|2|3)
+ * @bg_type: T10-DIF block guard type (CRC|CSUM)
+ * @pi_interval: protection information interval.
+ * @bg: seed of guard computation.
+ * @app_tag: application tag of guard block
+ * @ref_tag: initial guard block reference tag.
+ * @type3_inc_reftag: T10-DIF type 3 does not state
+ *     about the reference tag, it is the user
+ *     choice to increment it or not.
+ */
+struct ib_t10_dif_domain {
+	enum ib_t10_dif_type	type;
+	enum ib_t10_dif_bg_type bg_type;
+	u16			pi_interval;
+	u16			bg;
+	u16			app_tag;
+	u32			ref_tag;
+	bool			type3_inc_reftag;
+};
+
+/**
+ * struct ib_sig_domain - Parameters for signature domain
+ * @sig_type: specific signauture type
+ * @sig: union of all signature domain attributes that may
+ *     be used to set domain layout.
+ */
+struct ib_sig_domain {
+	enum ib_signature_type sig_type;
+	union {
+		struct ib_t10_dif_domain dif;
+	} sig;
+};
+
+/**
+ * struct ib_sig_attrs - Parameters for signature handover operation
+ * @check_mask: bitmask for signature byte check (8 bytes)
+ * @mem: memory domain layout desciptor.
+ * @wire: wire domain layout desciptor.
+ */
+struct ib_sig_attrs {
+	u8			check_mask;
+	struct ib_sig_domain	mem;
+	struct ib_sig_domain	wire;
+};
+
+enum ib_sig_err_type {
+	IB_SIG_BAD_GUARD,
+	IB_SIG_BAD_REFTAG,
+	IB_SIG_BAD_APPTAG,
+};
+
+/**
+ * struct ib_sig_err - signature error descriptor
+ */
+struct ib_sig_err {
+	enum ib_sig_err_type	err_type;
+	u32			expected;
+	u32			actual;
+	u64			sig_err_offset;
+	u32			key;
+};
+
+enum ib_mr_status_check {
+	IB_MR_CHECK_SIG_STATUS = 1,
+};
+
+/**
+ * struct ib_mr_status - Memory region status container
+ *
+ * @fail_status: Bitmask of MR checks status. For each
+ *     failed check a corresponding status bit is set.
+ * @sig_err: Additional info for IB_MR_CEHCK_SIG_STATUS
+ *     failure.
+ */
+struct ib_mr_status {
+	u32		    fail_status;
+	struct ib_sig_err   sig_err;
+};
+
 /**
  * mult_to_ib_rate - Convert a multiple of 2.5 Gbit/sec to an IB rate
  * enum.
@@ -660,6 +782,7 @@ enum ib_qp_create_flags {
 	IB_QP_CREATE_IPOIB_UD_LSO		= 1 << 0,
 	IB_QP_CREATE_BLOCK_MULTICAST_LOOPBACK	= 1 << 1,
 	IB_QP_CREATE_NETIF_QP			= 1 << 5,
+	IB_QP_CREATE_SIGNATURE_EN		= 1 << 6,
 	/* reserve bits 26-31 for low level drivers' internal use */
 	IB_QP_CREATE_RESERVED_START		= 1 << 26,
 	IB_QP_CREATE_RESERVED_END		= 1 << 31,
@@ -824,6 +947,7 @@ enum ib_wr_opcode {
 	IB_WR_MASKED_ATOMIC_CMP_AND_SWP,
 	IB_WR_MASKED_ATOMIC_FETCH_AND_ADD,
 	IB_WR_BIND_MW,
+	IB_WR_REG_SIG_MR,
 	/* reserve values for low level drivers' internal use.
 	 * These values will not be used at all in the ib core layer.
 	 */
@@ -929,6 +1053,12 @@ struct ib_send_wr {
 			u32                      rkey;
 			struct ib_mw_bind_info   bind_info;
 		} bind_mw;
+		struct {
+			struct ib_sig_attrs    *sig_attrs;
+			struct ib_mr	       *sig_mr;
+			int			access_flags;
+			struct ib_sge	       *prot;
+		} sig_handover;
 	} wr;
 	u32			xrc_remote_srq_num;	/* XRC TGT QPs only */
 };
@@ -1474,6 +1604,8 @@ struct ib_device {
 						  *flow_attr,
 						  int domain);
 	int			   (*destroy_flow)(struct ib_flow *flow_id);
+	int			   (*check_mr_status)(struct ib_mr *mr, u32 check_mask,
+						      struct ib_mr_status *mr_status);
 
 	struct ib_dma_mapping_ops   *dma_ops;
 
@@ -2473,4 +2605,19 @@ static inline int ib_check_mr_access(int flags)
 	return 0;
 }
 
+/**
+ * ib_check_mr_status: lightweight check of MR status.
+ *     This routine may provide status checks on a selected
+ *     ib_mr. first use is for signature status check.
+ *
+ * @mr: A memory region.
+ * @check_mask: Bitmask of which checks to perform from
+ *     ib_mr_status_check enumeration.
+ * @mr_status: The container of relevant status checks.
+ *     failed checks will be indicated in the status bitmask
+ *     and the relevant info shall be in the error item.
+ */
+int ib_check_mr_status(struct ib_mr *mr, u32 check_mask,
+		       struct ib_mr_status *mr_status);
+
 #endif /* IB_VERBS_H */