net/mlx5: FPGA, Add SBU infrastructure

Add interface to initialize and interact with Innova FPGA SBU
connections.
A client driver may use these functions to set up a high-speed DMA
connection with its SBU hardware logic, and send/receive messages
over this connection.

A later patch in this patchset will make use of these functions for
Innova IPSec offload in mlx5 Ethernet driver.

Add commands to retrieve Innova FPGA SBU capabilities, and to
read/write Innova FPGA configuration space registers and memory,
over internal I2C.

At high level, the FPGA configuration space is divided such:
 0x00000000 - 0x007fffff is reserved for the SBU
 0x00800000 - 0xffffffff is reserved for the Shell
0x400000000 - ...        is DDR memory

A later patchset will add support for accessing FPGA CrSpace and memory
over a high-speed connection. This is the reason for the ACCESS_TYPE
enumeration, which currently only supports I2C.

Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>

1 files changed, 98 insertions, 0 deletions

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/fpga/sdk.h b/drivers/net/ethernet/mellanox/mlx5/core/fpga/sdk.h
index 331798d..baa537e 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/fpga/sdk.h
+++ b/drivers/net/ethernet/mellanox/mlx5/core/fpga/sdk.h
@@ -42,6 +42,11 @@
  * This header defines the in-kernel API for Innova FPGA client drivers.
  */
 
+enum mlx5_fpga_access_type {
+	MLX5_FPGA_ACCESS_TYPE_I2C = 0x0,
+	MLX5_FPGA_ACCESS_TYPE_DONTCARE = 0x0,
+};
+
 struct mlx5_fpga_conn;
 struct mlx5_fpga_device;
 
@@ -103,4 +108,97 @@ struct mlx5_fpga_conn_attr {
 	void *cb_arg;
 };
 
+/**
+ * mlx5_fpga_sbu_conn_create() - Initialize a new FPGA SBU connection
+ * @fdev: The FPGA device
+ * @attr: Attributes of the new connection
+ *
+ * Sets up a new FPGA SBU connection with the specified attributes.
+ * The receive callback function may be called for incoming messages even
+ * before this function returns.
+ *
+ * The caller must eventually destroy the connection by calling
+ * mlx5_fpga_sbu_conn_destroy.
+ *
+ * Return: A new connection, or ERR_PTR() error value otherwise.
+ */
+struct mlx5_fpga_conn *
+mlx5_fpga_sbu_conn_create(struct mlx5_fpga_device *fdev,
+			  struct mlx5_fpga_conn_attr *attr);
+
+/**
+ * mlx5_fpga_sbu_conn_destroy() - Destroy an FPGA SBU connection
+ * @conn: The FPGA SBU connection to destroy
+ *
+ * Cleans up an FPGA SBU connection which was previously created with
+ * mlx5_fpga_sbu_conn_create.
+ */
+void mlx5_fpga_sbu_conn_destroy(struct mlx5_fpga_conn *conn);
+
+/**
+ * mlx5_fpga_sbu_conn_sendmsg() - Queue the transmission of a packet
+ * @fdev: An FPGA SBU connection
+ * @buf: The packet buffer
+ *
+ * Queues a packet for transmission over an FPGA SBU connection.
+ * The buffer should not be modified or freed until completion.
+ * Upon completion, the buf's complete() callback is invoked, indicating the
+ * success or error status of the transmission.
+ *
+ * Return: 0 if successful, or an error value otherwise.
+ */
+int mlx5_fpga_sbu_conn_sendmsg(struct mlx5_fpga_conn *conn,
+			       struct mlx5_fpga_dma_buf *buf);
+
+/**
+ * mlx5_fpga_mem_read() - Read from FPGA memory address space
+ * @fdev: The FPGA device
+ * @size: Size of chunk to read, in bytes
+ * @addr: Starting address to read from, in FPGA address space
+ * @buf: Buffer to read into
+ * @access_type: Method for reading
+ *
+ * Reads from the specified address into the specified buffer.
+ * The address may point to configuration space or to DDR.
+ * Large reads may be performed internally as several non-atomic operations.
+ * This function may sleep, so should not be called from atomic contexts.
+ *
+ * Return: 0 if successful, or an error value otherwise.
+ */
+int mlx5_fpga_mem_read(struct mlx5_fpga_device *fdev, size_t size, u64 addr,
+		       void *buf, enum mlx5_fpga_access_type access_type);
+
+/**
+ * mlx5_fpga_mem_write() - Write to FPGA memory address space
+ * @fdev: The FPGA device
+ * @size: Size of chunk to write, in bytes
+ * @addr: Starting address to write to, in FPGA address space
+ * @buf: Buffer which contains data to write
+ * @access_type: Method for writing
+ *
+ * Writes the specified buffer data to FPGA memory at the specified address.
+ * The address may point to configuration space or to DDR.
+ * Large writes may be performed internally as several non-atomic operations.
+ * This function may sleep, so should not be called from atomic contexts.
+ *
+ * Return: 0 if successful, or an error value otherwise.
+ */
+int mlx5_fpga_mem_write(struct mlx5_fpga_device *fdev, size_t size, u64 addr,
+			void *buf, enum mlx5_fpga_access_type access_type);
+
+/**
+ * mlx5_fpga_get_sbu_caps() - Read the SBU capabilities
+ * @fdev: The FPGA device
+ * @size: Size of the buffer to read into
+ * @buf: Buffer to read the capabilities into
+ *
+ * Reads the FPGA SBU capabilities into the specified buffer.
+ * The format of the capabilities buffer is SBU-dependent.
+ *
+ * Return: 0 if successful
+ *         -EINVAL if the buffer is not large enough to contain SBU caps
+ *         or any other error value otherwise.
+ */
+int mlx5_fpga_get_sbu_caps(struct mlx5_fpga_device *fdev, int size, void *buf);
+
 #endif /* MLX5_FPGA_SDK_H */