fm10k: Add support for mailbox

This patch adds generic mailbox support.  The general idea of the mailboxes
is to use a pair of ring buffers, one for request, one for response to send
data between the local driver and some remote entity be it the PF of the
Switch Manager.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 240 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_mbx.h b/drivers/net/ethernet/intel/fm10k/fm10k_mbx.h
new file mode 100644
index 000000000000..cb7aa4af9437
--- /dev/null
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_mbx.h
@@ -0,0 +1,240 @@
+/* Intel Ethernet Switch Host Interface Driver
+ * Copyright(c) 2013 - 2014 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Contact Information:
+ * e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
+ * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
+ */
+
+#ifndef _FM10K_MBX_H_
+#define _FM10K_MBX_H_
+
+/* forward declaration */
+struct fm10k_mbx_info;
+
+#include "fm10k_type.h"
+#include "fm10k_tlv.h"
+
+/* PF Mailbox Registers */
+#define FM10K_MBMEM(_n)		((_n) + 0x18000)
+#define FM10K_MBMEM_VF(_n, _m)	(((_n) * 0x10) + (_m) + 0x18000)
+#define FM10K_MBMEM_SM(_n)	((_n) + 0x18400)
+#define FM10K_MBMEM_PF(_n)	((_n) + 0x18600)
+/* XOR provides means of switching from Tx to Rx FIFO */
+#define FM10K_MBMEM_PF_XOR	(FM10K_MBMEM_SM(0) ^ FM10K_MBMEM_PF(0))
+#define FM10K_MBX(_n)		((_n) + 0x18800)
+#define FM10K_MBX_REQ				0x00000002
+#define FM10K_MBX_ACK				0x00000004
+#define FM10K_MBX_REQ_INTERRUPT			0x00000008
+#define FM10K_MBX_ACK_INTERRUPT			0x00000010
+#define FM10K_MBX_INTERRUPT_ENABLE		0x00000020
+#define FM10K_MBX_INTERRUPT_DISABLE		0x00000040
+#define FM10K_MBICR(_n)		((_n) + 0x18840)
+#define FM10K_GMBX		0x18842
+
+/* VF Mailbox Registers */
+#define FM10K_VFMBX		0x00010
+#define FM10K_VFMBMEM(_n)	((_n) + 0x00020)
+#define FM10K_VFMBMEM_LEN	16
+#define FM10K_VFMBMEM_VF_XOR	(FM10K_VFMBMEM_LEN / 2)
+
+/* Delays/timeouts */
+#define FM10K_MBX_DISCONNECT_TIMEOUT		500
+#define FM10K_MBX_POLL_DELAY			19
+#define FM10K_MBX_INT_DELAY			20
+
+/* PF/VF Mailbox state machine
+ *
+ * +----------+	    connect()	+----------+
+ * |  CLOSED  | --------------> |  CONNECT |
+ * +----------+			+----------+
+ *   ^				  ^	 |
+ *   | rcv:	      rcv:	  |	 | rcv:
+ *   |  Connect	       Disconnect |	 |  Connect
+ *   |  Disconnect     Error	  |	 |  Data
+ *   |				  |	 |
+ *   |				  |	 V
+ * +----------+   disconnect()	+----------+
+ * |DISCONNECT| <-------------- |   OPEN   |
+ * +----------+			+----------+
+ *
+ * The diagram above describes the PF/VF mailbox state machine.  There
+ * are four main states to this machine.
+ * Closed: This state represents a mailbox that is in a standby state
+ *	   with interrupts disabled.  In this state the mailbox should not
+ *	   read the mailbox or write any data.  The only means of exiting
+ *	   this state is for the system to make the connect() call for the
+ *	   mailbox, it will then transition to the connect state.
+ * Connect: In this state the mailbox is seeking a connection.  It will
+ *	    post a connect message with no specified destination and will
+ *	    wait for a reply from the other side of the mailbox.  This state
+ *	    is exited when either a connect with the local mailbox as the
+ *	    destination is received or when a data message is received with
+ *	    a valid sequence number.
+ * Open: In this state the mailbox is able to transfer data between the local
+ *       entity and the remote.  It will fall back to connect in the event of
+ *       receiving either an error message, or a disconnect message.  It will
+ *       transition to disconnect on a call to disconnect();
+ * Disconnect: In this state the mailbox is attempting to gracefully terminate
+ *	       the connection.  It will do so at the first point where it knows
+ *	       that the remote endpoint is either done sending, or when the
+ *	       remote endpoint has fallen back into connect.
+ */
+enum fm10k_mbx_state {
+	FM10K_STATE_CLOSED,
+	FM10K_STATE_CONNECT,
+	FM10K_STATE_OPEN,
+	FM10K_STATE_DISCONNECT,
+};
+
+/* macros for retriving and setting header values */
+#define FM10K_MSG_HDR_MASK(name) \
+	((0x1u << FM10K_MSG_##name##_SIZE) - 1)
+#define FM10K_MSG_HDR_FIELD_SET(value, name) \
+	(((u32)(value) & FM10K_MSG_HDR_MASK(name)) << FM10K_MSG_##name##_SHIFT)
+#define FM10K_MSG_HDR_FIELD_GET(value, name) \
+	((u16)((value) >> FM10K_MSG_##name##_SHIFT) & FM10K_MSG_HDR_MASK(name))
+
+/* HNI/SM Mailbox FIFO format
+ *    3                   2                   1                   0
+ *  1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+ * +-------+-----------------------+-------+-----------------------+
+ * | Error |      Remote Head      |Version|      Local Tail       |
+ * +-------+-----------------------+-------+-----------------------+
+ * |                                                               |
+ * .                        Local FIFO Data                        .
+ * .                                                               .
+ * +-------+-----------------------+-------+-----------------------+
+ *
+ * The layout above describes the format for the FIFOs used by the host
+ * network interface and the switch manager to communicate messages back
+ * and forth.  Both the HNI and the switch maintain one such FIFO.  The
+ * layout in memory has the switch manager FIFO followed immediately by
+ * the HNI FIFO.  For this reason I am using just the pointer to the
+ * HNI FIFO in the mailbox ops as the offset between the two is fixed.
+ *
+ * The header for the FIFO is broken out into the following fields:
+ * Local Tail:  Offset into FIFO region for next DWORD to write.
+ * Version:  Version info for mailbox, only values of 0/1 are supported.
+ * Remote Head:  Offset into remote FIFO to indicate how much we have read.
+ * Error: Error indication, values TBD.
+ */
+
+/* version number for switch manager mailboxes */
+#define FM10K_SM_MBX_VERSION		1
+#define FM10K_SM_MBX_FIFO_LEN		(FM10K_MBMEM_PF_XOR - 1)
+
+/* offsets shared between all SM FIFO headers */
+#define FM10K_MSG_SM_TAIL_SHIFT			0
+#define FM10K_MSG_SM_TAIL_SIZE			12
+#define FM10K_MSG_SM_VER_SHIFT			12
+#define FM10K_MSG_SM_VER_SIZE			4
+#define FM10K_MSG_SM_HEAD_SHIFT			16
+#define FM10K_MSG_SM_HEAD_SIZE			12
+#define FM10K_MSG_SM_ERR_SHIFT			28
+#define FM10K_MSG_SM_ERR_SIZE			4
+
+/* All error messages returned by mailbox functions
+ * The value -511 is 0xFE01 in hex.  The idea is to order the errors
+ * from 0xFE01 - 0xFEFF so error codes are easily visible in the mailbox
+ * messages.  This also helps to avoid error number collisions as Linux
+ * doesn't appear to use error numbers 256 - 511.
+ */
+#define FM10K_MBX_ERR(_n) ((_n) - 512)
+#define FM10K_MBX_ERR_NO_MBX		FM10K_MBX_ERR(0x01)
+#define FM10K_MBX_ERR_NO_SPACE		FM10K_MBX_ERR(0x03)
+#define FM10K_MBX_ERR_TAIL		FM10K_MBX_ERR(0x05)
+#define FM10K_MBX_ERR_HEAD		FM10K_MBX_ERR(0x06)
+#define FM10K_MBX_ERR_SRC		FM10K_MBX_ERR(0x08)
+#define FM10K_MBX_ERR_TYPE		FM10K_MBX_ERR(0x09)
+#define FM10K_MBX_ERR_SIZE		FM10K_MBX_ERR(0x0B)
+#define FM10K_MBX_ERR_BUSY		FM10K_MBX_ERR(0x0C)
+#define FM10K_MBX_ERR_RSVD0		FM10K_MBX_ERR(0x0E)
+#define FM10K_MBX_ERR_CRC		FM10K_MBX_ERR(0x0F)
+
+#define FM10K_MBX_CRC_SEED		0xFFFF
+
+struct fm10k_mbx_ops {
+	s32 (*connect)(struct fm10k_hw *, struct fm10k_mbx_info *);
+	void (*disconnect)(struct fm10k_hw *, struct fm10k_mbx_info *);
+	bool (*rx_ready)(struct fm10k_mbx_info *);
+	bool (*tx_ready)(struct fm10k_mbx_info *, u16);
+	bool (*tx_complete)(struct fm10k_mbx_info *);
+	s32 (*enqueue_tx)(struct fm10k_hw *, struct fm10k_mbx_info *,
+			  const u32 *);
+	s32 (*process)(struct fm10k_hw *, struct fm10k_mbx_info *);
+	s32 (*register_handlers)(struct fm10k_mbx_info *,
+				 const struct fm10k_msg_data *);
+};
+
+struct fm10k_mbx_fifo {
+	u32 *buffer;
+	u16 head;
+	u16 tail;
+	u16 size;
+};
+
+/* size of buffer to be stored in mailbox for FIFOs */
+#define FM10K_MBX_TX_BUFFER_SIZE	512
+#define FM10K_MBX_RX_BUFFER_SIZE	128
+#define FM10K_MBX_BUFFER_SIZE \
+	(FM10K_MBX_TX_BUFFER_SIZE + FM10K_MBX_RX_BUFFER_SIZE)
+
+/* minimum and maximum message size in dwords */
+#define FM10K_MBX_MSG_MAX_SIZE \
+	((FM10K_MBX_TX_BUFFER_SIZE - 1) & (FM10K_MBX_RX_BUFFER_SIZE - 1))
+#define FM10K_VFMBX_MSG_MTU	((FM10K_VFMBMEM_LEN / 2) - 1)
+
+#define FM10K_MBX_INIT_TIMEOUT	2000 /* number of retries on mailbox */
+#define FM10K_MBX_INIT_DELAY	500  /* microseconds between retries */
+
+struct fm10k_mbx_info {
+	/* function pointers for mailbox operations */
+	struct fm10k_mbx_ops ops;
+	const struct fm10k_msg_data *msg_data;
+
+	/* message FIFOs */
+	struct fm10k_mbx_fifo rx;
+	struct fm10k_mbx_fifo tx;
+
+	/* delay for handling timeouts */
+	u32 timeout;
+	u32 udelay;
+
+	/* mailbox state info */
+	u32 mbx_reg, mbmem_reg, mbx_lock, mbx_hdr;
+	u16 max_size, mbmem_len;
+	u16 tail, tail_len, pulled;
+	u16 head, head_len, pushed;
+	u16 local, remote;
+	enum fm10k_mbx_state state;
+
+	/* result of last mailbox test */
+	s32 test_result;
+
+	/* statistics */
+	u64 tx_busy;
+	u64 tx_dropped;
+	u64 tx_messages;
+	u64 tx_dwords;
+	u64 rx_messages;
+	u64 rx_dwords;
+	u64 rx_parse_err;
+
+	/* Buffer to store messages */
+	u32 buffer[FM10K_MBX_BUFFER_SIZE];
+};
+
+#endif /* _FM10K_MBX_H_ */