sdio: allow for mmc_claim_host to be aborted

It is sometimes necessary to give up on trying to claim the host lock,
especially if that happens in a thread that has to be stopped.

While at it, fix the description for mmc_claim_host() which was wrong.

Signed-off-by: Nicolas Pitre <npitre@mvista.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 43a9273..8945da9 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -114,7 +114,18 @@
 
 extern void mmc_set_data_timeout(struct mmc_data *, const struct mmc_card *);
 
-extern void mmc_claim_host(struct mmc_host *host);
+extern int __mmc_claim_host(struct mmc_host *host, atomic_t *abort);
 extern void mmc_release_host(struct mmc_host *host);
 
+/**
+ *	mmc_claim_host - exclusively claim a host
+ *	@host: mmc host to claim
+ *
+ *	Claim a host for a set of operations.
+ */
+static inline void mmc_claim_host(struct mmc_host *host)
+{
+	__mmc_claim_host(host, NULL);
+}
+
 #endif