Merge tag 'for-linus-5.16-1' of https://github.com/cminyard/linux-ipmi

Pull IPMI driver updates from Corey Minyard:
 "A new type of low-level IPMI driver is added for direct communication
  over the IPMI message bus without a BMC between the driver and the
  bus.

  Other than that, lots of little bug fixes and enhancements"

* tag 'for-linus-5.16-1' of https://github.com/cminyard/linux-ipmi:
  ipmi: kcs_bmc: Fix a memory leak in the error handling path of 'kcs_bmc_serio_add_device()'
  char: ipmi: replace snprintf in show functions with sysfs_emit
  ipmi: ipmb: fix dependencies to eliminate build error
  ipmi:ipmb: Add OF support
  ipmi: bt: Add ast2600 compatible string
  ipmi: bt-bmc: Use registers directly
  ipmi: ipmb: Fix off-by-one size check on rcvlen
  ipmi:ssif: Use depends on, not select, for I2C
  ipmi: Add docs for the IPMI IPMB driver
  ipmi: Add docs for IPMB direct addressing
  ipmi:ipmb: Add initial support for IPMI over IPMB
  ipmi: Add support for IPMB direct messages
  ipmi: Export ipmb_checksum()
  ipmi: Fix a typo
  ipmi: Check error code before processing BMC response
  ipmi:devintf: Return a proper error when recv buffer too small
  ipmi: Disable some operations during a panic
  ipmi:watchdog: Set panic count to proper value on a panic

3 files changed, 77 insertions, 1 deletions

diff --git a/include/linux/ipmi.h b/include/linux/ipmi.h
index 52850a02a3d0..163831a087ef 100644
--- a/include/linux/ipmi.h
+++ b/include/linux/ipmi.h
@@ -335,4 +335,7 @@ extern int ipmi_get_smi_info(int if_num, struct ipmi_smi_info *data);
 
 #define GET_DEVICE_ID_MAX_RETRY		5
 
+/* Helper function for computing the IPMB checksum of some data. */
+unsigned char ipmb_checksum(unsigned char *data, int size);
+
 #endif /* __LINUX_IPMI_H */
diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
index deec18b8944a..9277d21c2690 100644
--- a/include/linux/ipmi_smi.h
+++ b/include/linux/ipmi_smi.h
@@ -39,6 +39,59 @@ struct ipmi_smi;
 #define IPMI_WATCH_MASK_CHECK_COMMANDS	(1 << 2)
 
 /*
+ * SMI messages
+ *
+ * When communicating with an SMI, messages come in two formats:
+ *
+ * * Normal (to a BMC over a BMC interface)
+ *
+ * * IPMB (over a IPMB to another MC)
+ *
+ * When normal, commands are sent using the format defined by a
+ * standard message over KCS (NetFn must be even):
+ *
+ *   +-----------+-----+------+
+ *   | NetFn/LUN | Cmd | Data |
+ *   +-----------+-----+------+
+ *
+ * And responses, similarly, with an completion code added (NetFn must
+ * be odd):
+ *
+ *   +-----------+-----+------+------+
+ *   | NetFn/LUN | Cmd | CC   | Data |
+ *   +-----------+-----+------+------+
+ *
+ * With normal messages, only commands are sent and only responses are
+ * received.
+ *
+ * In IPMB mode, we are acting as an IPMB device. Commands will be in
+ * the following format (NetFn must be even):
+ *
+ *   +-------------+------+-------------+-----+------+
+ *   | NetFn/rsLUN | Addr | rqSeq/rqLUN | Cmd | Data |
+ *   +-------------+------+-------------+-----+------+
+ *
+ * Responses will using the following format:
+ *
+ *   +-------------+------+-------------+-----+------+------+
+ *   | NetFn/rqLUN | Addr | rqSeq/rsLUN | Cmd | CC   | Data |
+ *   +-------------+------+-------------+-----+------+------+
+ *
+ * This is similar to the format defined in the IPMB manual section
+ * 2.11.1 with the checksums and the first address removed.  Also, the
+ * address is always the remote address.
+ *
+ * IPMB messages can be commands and responses in both directions.
+ * Received commands are handled as received commands from the message
+ * queue.
+ */
+
+enum ipmi_smi_msg_type {
+	IPMI_SMI_MSG_TYPE_NORMAL = 0,
+	IPMI_SMI_MSG_TYPE_IPMB_DIRECT
+};
+
+/*
  * Messages to/from the lower layer.  The smi interface will take one
  * of these to send. After the send has occurred and a response has
  * been received, it will report this same data structure back up to
@@ -54,6 +107,8 @@ struct ipmi_smi;
 struct ipmi_smi_msg {
 	struct list_head link;
 
+	enum ipmi_smi_msg_type type;
+
 	long    msgid;
 	void    *user_data;
 
@@ -73,6 +128,10 @@ struct ipmi_smi_msg {
 struct ipmi_smi_handlers {
 	struct module *owner;
 
+	/* Capabilities of the SMI. */
+#define IPMI_SMI_CAN_HANDLE_IPMB_DIRECT		(1 << 0)
+	unsigned int flags;
+
 	/*
 	 * The low-level interface cannot start sending messages to
 	 * the upper layer until this function is called.  This may
diff --git a/include/uapi/linux/ipmi.h b/include/uapi/linux/ipmi.h
index 32d148309b16..966c3070959b 100644
--- a/include/uapi/linux/ipmi.h
+++ b/include/uapi/linux/ipmi.h
@@ -81,6 +81,20 @@ struct ipmi_ipmb_addr {
 };
 
 /*
+ * Used for messages received directly from an IPMB that have not gone
+ * through a MC.  This is for systems that sit right on an IPMB so
+ * they can receive commands and respond to them.
+ */
+#define IPMI_IPMB_DIRECT_ADDR_TYPE	0x81
+struct ipmi_ipmb_direct_addr {
+	int           addr_type;
+	short         channel;
+	unsigned char slave_addr;
+	unsigned char rs_lun;
+	unsigned char rq_lun;
+};
+
+/*
  * A LAN Address.  This is an address to/from a LAN interface bridged
  * by the BMC, not an address actually out on the LAN.
  *
@@ -158,7 +172,7 @@ struct kernel_ipmi_msg {
  * is used for the receive in-kernel interface and in the receive
  * IOCTL.
  *
- * The "IPMI_RESPONSE_RESPNOSE_TYPE" is a little strange sounding, but
+ * The "IPMI_RESPONSE_RESPONSE_TYPE" is a little strange sounding, but
  * it allows you to get the message results when you send a response
  * message.
  */