mmc: allow upper layers to know immediately if card has been removed

Add a function mmc_detect_card_removed() which upper layers can use to
determine immediately if a card has been removed. This function should
be called after an I/O request fails so that all queued I/O requests
can be errored out immediately instead of waiting for the card device
to be removed.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 174a844..87a976c 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -180,6 +180,8 @@
 
 extern int mmc_flush_cache(struct mmc_card *);
 
+extern int mmc_detect_card_removed(struct mmc_host *host);
+
 /**
  *	mmc_claim_host - exclusively claim a host
  *	@host: mmc host to claim