ipmi: Refactored ipmi layer to use generic backend

The initial implementation of the ipmi stack was still tightly coupled
with the backend (in this case bt). This patch refactors the ipmi code
to use a generic backend device.

The core ipmi messaging functionality and the implementation of
specific commands has also been split into different files.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 53 insertions, 26 deletions

diff --git a/include/bt.h b/include/bt.h
index 5f8a91e..1763d9f 100644
--- a/include/bt.h
+++ b/include/bt.h
@@ -17,21 +17,7 @@
 #ifndef __BT_H
 #define __BT_H
 
-#include <ipmi.h>
-
 /* Initialise the BT interface */
-void bt_init(void (*ipmi_cmd_done)(struct ipmi_msg *));
-
-/* Allocate an BT-IPMI message */
-struct ipmi_msg *bt_alloc_ipmi_msg(size_t request_size, size_t response_size);
-
-/* Free a BT-IPMI message */
-void bt_free_ipmi_msg(struct ipmi_msg *ipmi_msg);
-
-/* Add an IPMI message to the BT queue and wait for a resposne */
-int bt_add_ipmi_msg_wait(struct ipmi_msg *msg);
-
-/* Remove an IPMI message from the BT queue */
-void bt_del_ipmi_msg(struct ipmi_msg *ipmi_msg);
+void bt_init(void);
 
 #endif
diff --git a/include/ipmi.h b/include/ipmi.h
index 6181c53..78eb5cd 100644
--- a/include/ipmi.h
+++ b/include/ipmi.h
@@ -22,8 +22,6 @@
 /*
  * IPMI codes as defined by the standard.
  */
-#define IPMI_NETFN_APP_REQUEST		0x06
-#define IPMI_NETFN_APP_RESPONSE		0x07
 #define IPMI_GET_DEVICE_ID_CMD		0x01
 #define IPMI_COLD_RESET_CMD		0x02
 #define IPMI_WARM_RESET_CMD		0x03
@@ -54,8 +52,6 @@
 #define IPMI_CHASSIS_GET_SYS_BOOT_OPT_CMD	0x0b
 #define IPMI_CHASSIS_GET_POH_COUNTER_CMD	0x0f
 
-#define IPMI_NETFN_CHASSIS_REQUEST		0x00
-#define IPMI_NETFN_CHASSIS_RESPONSE		0x01
 
 /* 28.3. Chassis Control Command */
 #define   IPMI_CHASSIS_PWR_DOWN 		0x00
@@ -65,11 +61,18 @@
 #define   IPMI_CHASSIS_PULSE_DIAG		0x04
 #define   IPMI_CHASSIS_SOFT_SHUTDOWN		0x05
 
-#define IPMI_NETFN_STORAGE_REQUEST	0x0a
-#define IPMI_NETFN_STORAGE_RESPONSE	0x0b
-#define   IPMI_GET_SEL_INFO_CMD		0x40
-#define   IPMI_GET_SEL_TIME_CMD		0x48
-#define   IPMI_SET_SEL_TIME_CMD		0x49
+#define IPMI_CODE(netfn, cmd)		((netfn) << 8 | (cmd))
+#define IPMI_CMD(code)			((code) & 0xff)
+#define IPMI_NETFN(code)		((code) >> 8 & 0xff)
+
+#define IPMI_NETFN_CHASSIS		0x00
+#define IPMI_NETFN_STORAGE		0x0a
+#define IPMI_NETFN_APP			0x06
+
+#define IPMI_GET_SEL_INFO		IPMI_CODE(IPMI_NETFN_STORAGE, 0x40)
+#define IPMI_GET_SEL_TIME		IPMI_CODE(IPMI_NETFN_STORAGE, 0x48)
+#define IPMI_SET_SEL_TIME		IPMI_CODE(IPMI_NETFN_STORAGE, 0x49)
+#define IPMI_CHASSIS_CONTROL		IPMI_CODE(IPMI_NETFN_CHASSIS, 0x02)
 
 /*
  * IPMI response codes.
@@ -87,19 +90,57 @@
 #define IPMI_NAK_ON_WRITE_ERR		0x83
 #define IPMI_ERR_UNSPECIFIED		0xff
 
+#define IPMI_DEFAULT_INTERFACE		0
+
+struct ipmi_backend;
 struct ipmi_msg {
+	struct ipmi_backend *backend;
 	uint8_t netfn;
 	uint8_t cmd;
 	uint8_t cc;
-	uint8_t req_data_len;
-	uint8_t resp_data_len;
+
+	/* Called when a response is received to the ipmi message */
+	void (*complete)(struct ipmi_msg *);
+
+	/* Called if non-NULL when the ipmi layer detects an error */
+	void (*error)(struct ipmi_msg *);
+	void *user_data;
+
+	uint8_t req_size;
+	uint8_t resp_size;
 	uint8_t *data;
 };
 
+struct ipmi_backend {
+	struct ipmi_msg *(*alloc_msg)(size_t, size_t);
+	void (*free_msg)(struct ipmi_msg *);
+	int (*queue_msg)(struct ipmi_msg *);
+	int (*dequeue_msg)(struct ipmi_msg *);
+};
+
 /* Initialise the IPMI interface */
 void ipmi_init(void);
 
+void ipmi_free_msg(struct ipmi_msg *msg);
+
+struct ipmi_msg *ipmi_mkmsg_simple(uint32_t code, void *req_data, size_t req_size);
+struct ipmi_msg *ipmi_mkmsg(int interface, uint32_t code,
+			    void (*complete)(struct ipmi_msg *),
+			    void *user_data, void *req_data, size_t req_size,
+			    size_t resp_size);
+
+int ipmi_sync_queue_msg(struct ipmi_msg *msg);
+
+/* Process a completed message */
+void ipmi_cmd_done(struct ipmi_msg *msg);
+
 /* Change the power state of the P8 */
 int64_t ipmi_opal_chassis_control(uint64_t request);
 
+/* Register a backend with the ipmi core. Currently we only support one. */
+void ipmi_register_backend(struct ipmi_backend *backend);
+
+/* Register rtc ipmi commands with as opal callbacks. */
+void ipmi_rtc_init(void);
+
 #endif