transport: mbox: Centralise errno translation

We only need to do it once, after we've invoked the transport handler.
Previously it was distributed across the handler implementations which
was necessary while we were converting the handlers to standard errnos.

Change-Id: I76c02d768d297aa50bb9809b0392832d76046fc1
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>

1 files changed, 27 insertions, 67 deletions

diff --git a/transport_mbox.c b/transport_mbox.c
index 0d3d9b7..b0e0c04 100644
--- a/transport_mbox.c
+++ b/transport_mbox.c
@@ -38,9 +38,12 @@ struct errno_map {
 static const struct errno_map errno_map_v1[] = {
 	{ 0, MBOX_R_SUCCESS },
 	{ EACCES, MBOX_R_PARAM_ERROR },
+	{ EBADMSG, MBOX_R_PARAM_ERROR },
 	{ EBUSY, MBOX_R_SYSTEM_ERROR },
 	{ EINVAL, MBOX_R_PARAM_ERROR },
+	{ ENOTSUP, MBOX_R_PARAM_ERROR },
 	{ EPERM, MBOX_R_PARAM_ERROR },
+	{ EPROTO, MBOX_R_PARAM_ERROR },
 	{ ETIMEDOUT, MBOX_R_TIMEOUT },
 	{ -1, MBOX_R_SYSTEM_ERROR },
 };
@@ -48,9 +51,12 @@ static const struct errno_map errno_map_v1[] = {
 static const struct errno_map errno_map_v2[] = {
 	{ 0, MBOX_R_SUCCESS },
 	{ EACCES, MBOX_R_WINDOW_ERROR },
+	{ EBADMSG, MBOX_R_SEQ_ERROR },
 	{ EBUSY, MBOX_R_BUSY },
 	{ EINVAL, MBOX_R_PARAM_ERROR },
+	{ ENOTSUP, MBOX_R_PARAM_ERROR },
 	{ EPERM, MBOX_R_WINDOW_ERROR },
+	{ EPROTO, MBOX_R_PARAM_ERROR },
 	{ ETIMEDOUT, MBOX_R_TIMEOUT },
 	{ -1, MBOX_R_SYSTEM_ERROR },
 };
@@ -67,13 +73,14 @@ static inline int mbox_xlate_errno(struct mbox_context *context,
 	const struct errno_map *entry;
 
 	rc = -rc;
+	MSG_DBG("Translating errno %d: %s\n", rc, strerror(rc));
 	for(entry = errno_maps[context->version]; entry->rc != -1; entry++) {
 		if (rc == entry->rc) {
-			return -entry->mbox_errno;
+			return entry->mbox_errno;
 		}
 	}
 
-	return -entry->mbox_errno;
+	return entry->mbox_errno;
 }
 
 /*
@@ -168,12 +175,7 @@ int clr_bmc_events(struct mbox_context *context, uint8_t bmc_event,
 int mbox_handle_reset(struct mbox_context *context,
 			     union mbox_regs *req, struct mbox_msg *resp)
 {
-	int rc = context->protocol->reset(context);
-	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
-	}
-
-	return 0;
+	return context->protocol->reset(context);
 }
 
 /*
@@ -209,7 +211,7 @@ int mbox_handle_mbox_info(struct mbox_context *context,
 
 	rc = context->protocol->get_info(context, &io);
 	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
+		return rc;
 	}
 
 	resp->args[0] = io.resp.api_version;
@@ -243,7 +245,7 @@ int mbox_handle_flash_info(struct mbox_context *context,
 
 	rc = context->protocol->get_flash_info(context, &io);
 	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
+		return rc;
 	}
 
 	switch (context->version) {
@@ -330,12 +332,7 @@ int mbox_handle_create_window(struct mbox_context *context, bool ro,
 int mbox_handle_read_window(struct mbox_context *context,
 				   union mbox_regs *req, struct mbox_msg *resp)
 {
-	int rc = mbox_handle_create_window(context, true, req, resp);
-	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
-	}
-
-	return 0;
+	return mbox_handle_create_window(context, true, req, resp);
 }
 
 /*
@@ -360,12 +357,7 @@ int mbox_handle_read_window(struct mbox_context *context,
 int mbox_handle_write_window(struct mbox_context *context,
 				    union mbox_regs *req, struct mbox_msg *resp)
 {
-	int rc = mbox_handle_create_window(context, false, req, resp);
-	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
-	}
-
-	return 0;
+	return mbox_handle_create_window(context, false, req, resp);
 }
 
 /*
@@ -388,7 +380,6 @@ int mbox_handle_dirty_window(struct mbox_context *context,
 				    union mbox_regs *req, struct mbox_msg *resp)
 {
 	struct protocol_mark_dirty io;
-	int rc;
 
 	if (context->version == API_VERSION_1) {
 		io.req.v1.offset = get_u16(&req->msg.args[0]);
@@ -398,12 +389,7 @@ int mbox_handle_dirty_window(struct mbox_context *context,
 		io.req.v2.size = get_u16(&req->msg.args[2]);
 	}
 
-	rc = context->protocol->mark_dirty(context, &io);
-	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
-	}
-
-	return rc;
+	return context->protocol->mark_dirty(context, &io);
 }
 
 /*
@@ -423,22 +409,16 @@ int mbox_handle_erase_window(struct mbox_context *context,
 				    union mbox_regs *req, struct mbox_msg *resp)
 {
 	struct protocol_erase io;
-	int rc;
 
 	io.req.offset = get_u16(&req->msg.args[0]);
 	io.req.size = get_u16(&req->msg.args[2]);
 
 	if (!context->protocol->erase) {
 		MSG_ERR("Protocol Version invalid for Erase Command\n");
-		return -MBOX_R_PARAM_ERROR;
+		return -ENOTSUP;
 	}
 
-	rc = context->protocol->erase(context, &io);
-	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
-	}
-
-	return rc;
+	return context->protocol->erase(context, &io);
 }
 
 /*
@@ -462,19 +442,13 @@ int mbox_handle_flush_window(struct mbox_context *context,
 				    union mbox_regs *req, struct mbox_msg *resp)
 {
 	struct protocol_flush io = { 0 };
-	int rc;
 
 	if (context->version == API_VERSION_1) {
 		io.req.offset = get_u16(&req->msg.args[0]);
 		io.req.size = get_u32(&req->msg.args[2]);
 	}
 
-	rc = context->protocol->flush(context, &io);
-	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
-	}
-
-	return rc;
+	return context->protocol->flush(context, &io);
 }
 
 /*
@@ -492,18 +466,12 @@ int mbox_handle_close_window(struct mbox_context *context,
 				    union mbox_regs *req, struct mbox_msg *resp)
 {
 	struct protocol_close io = { 0 };
-	int rc;
 
 	if (context->version >= API_VERSION_2) {
 		io.req.flags = req->msg.args[0];
 	}
 
-	rc = context->protocol->close(context, &io);
-	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
-	}
-
-	return rc;
+	return context->protocol->close(context, &io);
 }
 
 /*
@@ -516,16 +484,10 @@ int mbox_handle_ack(struct mbox_context *context, union mbox_regs *req,
 			   struct mbox_msg *resp)
 {
 	struct protocol_ack io;
-	int rc;
 
 	io.req.flags = req->msg.args[0];
 
-	rc = context->protocol->ack(context, &io);
-	if (rc < 0) {
-		return mbox_xlate_errno(context, rc);
-	}
-
-	return 0;
+	return context->protocol->ack(context, &io);
 }
 
 /*
@@ -542,21 +504,20 @@ static int check_req_valid(struct mbox_context *context, union mbox_regs *req)
 
 	if (cmd > NUM_MBOX_CMDS) {
 		MSG_ERR("Unknown mbox command: %d\n", cmd);
-		return -MBOX_R_PARAM_ERROR;
+		return -ENOTSUP;
 	}
 
 	if (seq == context->prev_seq && cmd != MBOX_C_GET_MBOX_INFO) {
 		MSG_ERR("Invalid sequence number: %d, previous: %d\n", seq,
 			context->prev_seq);
-		return -MBOX_R_SEQ_ERROR;
+		return -EBADMSG;
 	}
 
 	if (context->state & STATE_SUSPENDED) {
 		if (cmd != MBOX_C_GET_MBOX_INFO && cmd != MBOX_C_ACK) {
 			MSG_ERR("Cannot use that cmd while suspended: %d\n",
 				cmd);
-			return context->version >= API_VERSION_2 ? -MBOX_R_BUSY
-						: -MBOX_R_PARAM_ERROR;
+			return -EBUSY;
 		}
 	}
 
@@ -564,7 +525,7 @@ static int check_req_valid(struct mbox_context *context, union mbox_regs *req)
 		if (cmd != MBOX_C_RESET_STATE && cmd != MBOX_C_GET_MBOX_INFO
 					      && cmd != MBOX_C_ACK) {
 			MSG_ERR("Must call GET_MBOX_INFO before %d\n", cmd);
-			return -MBOX_R_PARAM_ERROR;
+			return -EPROTO;
 		}
 	}
 
@@ -603,19 +564,18 @@ static int handle_mbox_req(struct mbox_context *context, union mbox_regs *req)
 
 	MSG_INFO("Received MBOX command: %u\n", req->msg.command);
 	rc = check_req_valid(context, req);
-	if (rc < 0) {
-		resp.response = -rc;
-	} else {
+	if (!rc) {
 		/* Commands start at 1 so we have to subtract 1 from the cmd */
 		mboxd_mbox_handler h = context->handlers[req->msg.command - 1];
 		rc = h(context, req, &resp);
 		if (rc < 0) {
 			MSG_ERR("Error handling mbox cmd: %d\n",
 				req->msg.command);
-			resp.response = -rc;
 		}
 	}
 
+	rc = mbox_xlate_errno(context, rc);
+	resp.response = rc;
 	context->prev_seq = req->msg.seq;
 
 	MSG_DBG("Writing MBOX response:\n");