First and foremost, avoid an obious race between two or more processes

trying to get MMC commands through to the SD/MMC host controller via the
emulated SCSI layer.  This is achieved by ensuring exclusive access to
the host controller for one process during any MMC command and during a
sequence of commands at the sdmmc(4) layer.

While at it, the command processing thread has been moved to sdmmc(4),
so as to simplify the implementation of future host controller drivers.
This should also pave the way for further cleanup of the code and for
new drivers.

Minor cleanups are included in this commit, as well.

1 files changed, 29 insertions, 12 deletions

diff --git a/sys/dev/sdmmc/sdmmc_mem.c b/sys/dev/sdmmc/sdmmc_mem.c
index c8cdaaa1e5b..a3daba6411d 100644
--- a/sys/dev/sdmmc/sdmmc_mem.c
+++ b/sys/dev/sdmmc/sdmmc_mem.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: sdmmc_mem.c,v 1.4 2006/06/29 01:40:51 uwe Exp $	*/
+/*	$OpenBSD: sdmmc_mem.c,v 1.5 2006/07/18 04:10:35 uwe Exp $	*/
 
 /*
  * Copyright (c) 2006 Uwe Stuehler <uwe@openbsd.org>
@@ -59,7 +59,6 @@ sdmmc_mem_enable(struct sdmmc_softc *sc)
 	 */
  mmc_mode:
 	if (sdmmc_mem_send_op_cond(sc, 0, &card_ocr) != 0) {
-		DPRINTF(("flags %x\n", sc->sc_flags));
 		if (ISSET(sc->sc_flags, SMF_SD_MODE) &&
 		    !ISSET(sc->sc_flags, SMF_IO_MODE)) {
 			/* Not a SD card, switch to MMC mode. */
@@ -213,10 +212,14 @@ sdmmc_mem_scan(struct sdmmc_softc *sc)
 int
 sdmmc_mem_init(struct sdmmc_softc *sc, struct sdmmc_function *sf)
 {
+	int error = 0;
+
+	SDMMC_LOCK(sc);
 	if (sdmmc_select_card(sc, sf) != 0 ||
 	    sdmmc_mem_set_blocklen(sc, sf) != 0)
-		return 1;
-	return 0;
+		error = 1;
+	SDMMC_UNLOCK(sc);
+	return error;
 }
 
 /*
@@ -230,6 +233,8 @@ sdmmc_mem_send_op_cond(struct sdmmc_softc *sc, u_int32_t ocr,
 	int error;
 	int i;
 
+	SDMMC_LOCK(sc);
+
 	/*
 	 * If we change the OCR value, retry the command until the OCR
 	 * we receive in response has the "CARD BUSY" bit set, meaning
@@ -257,6 +262,8 @@ sdmmc_mem_send_op_cond(struct sdmmc_softc *sc, u_int32_t ocr,
 	}
 	if (error == 0 && ocrp != NULL)
 		*ocrp = MMC_R3(cmd.c_resp);
+
+	SDMMC_UNLOCK(sc);
 	return error;
 }
 
@@ -280,14 +287,17 @@ sdmmc_mem_set_blocklen(struct sdmmc_softc *sc, struct sdmmc_function *sf)
 }
 
 int
-sdmmc_mem_read_block(struct sdmmc_softc *sc, struct sdmmc_function *sf,
-    int blkno, u_char *data, size_t datalen)
+sdmmc_mem_read_block(struct sdmmc_function *sf, int blkno, u_char *data,
+    size_t datalen)
 {
+	struct sdmmc_softc *sc = sf->sc;
 	struct sdmmc_command cmd;
 	int error;
 
+	SDMMC_LOCK(sc);
+
 	if ((error = sdmmc_select_card(sc, sf)) != 0)
-		return error;
+		goto err;
 
 	bzero(&cmd, sizeof cmd);
 	cmd.c_data = data;
@@ -300,7 +310,7 @@ sdmmc_mem_read_block(struct sdmmc_softc *sc, struct sdmmc_function *sf,
 
 	error = sdmmc_mmc_command(sc, &cmd);
 	if (error != 0)
-		return error;
+		goto err;
 
 	do {
 		bzero(&cmd, sizeof cmd);
@@ -313,18 +323,23 @@ sdmmc_mem_read_block(struct sdmmc_softc *sc, struct sdmmc_function *sf,
 		/* XXX time out */
 	} while (!ISSET(MMC_R1(cmd.c_resp), MMC_R1_READY_FOR_DATA));
 
+err:
+	SDMMC_UNLOCK(sc);
 	return error;
 }
 
 int
-sdmmc_mem_write_block(struct sdmmc_softc *sc, struct sdmmc_function *sf,
-    int blkno, u_char *data, size_t datalen)
+sdmmc_mem_write_block(struct sdmmc_function *sf, int blkno, u_char *data,
+    size_t datalen)
 {
+	struct sdmmc_softc *sc = sf->sc;
 	struct sdmmc_command cmd;
 	int error;
 
+	SDMMC_LOCK(sc);
+
 	if ((error = sdmmc_select_card(sc, sf)) != 0)
-		return error;
+		goto err;
 
 	bzero(&cmd, sizeof cmd);
 	cmd.c_data = data;
@@ -337,7 +352,7 @@ sdmmc_mem_write_block(struct sdmmc_softc *sc, struct sdmmc_function *sf,
 
 	error = sdmmc_mmc_command(sc, &cmd);
 	if (error != 0)
-		return error;
+		goto err;
 
 	do {
 		bzero(&cmd, sizeof cmd);
@@ -350,5 +365,7 @@ sdmmc_mem_write_block(struct sdmmc_softc *sc, struct sdmmc_function *sf,
 		/* XXX time out */
 	} while (!ISSET(MMC_R1(cmd.c_resp), MMC_R1_READY_FOR_DATA));
 
+err:
+	SDMMC_UNLOCK(sc);
 	return error;
 }