mmc: core: Fix ambiguous TRIM and DISCARD arg

Clean up the MMC_TRIM_ARGS define that became ambiguous with DISCARD
introduction.  While at it, let's fix one usage where MMC_TRIM_ARGS falsely
included DISCARD too.

Fixes: b3bf915308 ("mmc: core: new discard feature support at eMMC v4.5")
Signed-off-by: Christian Loehle <cloehle@hyperstone.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/11376b5714964345908f3990f17e0701@hyperstone.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/core/core.c

@@ -1484,6 +1484,11 @@ void mmc_init_erase(struct mmc_card *card)
 		card->pref_erase = 0;
 }
 
+static bool is_trim_arg(unsigned int arg)
+{
+	return (arg & MMC_TRIM_OR_DISCARD_ARGS) && arg != MMC_DISCARD_ARG;
+}
+
 static unsigned int mmc_mmc_erase_timeout(struct mmc_card *card,
 				          unsigned int arg, unsigned int qty)
 {
@@ -1766,7 +1771,7 @@ int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
 	    !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN))
 		return -EOPNOTSUPP;
 
-	if (mmc_card_mmc(card) && (arg & MMC_TRIM_ARGS) &&
+	if (mmc_card_mmc(card) && is_trim_arg(arg) &&
 	    !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN))
 		return -EOPNOTSUPP;
 
@@ -1796,7 +1801,7 @@ int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
 	 * identified by the card->eg_boundary flag.
 	 */
 	rem = card->erase_size - (from % card->erase_size);
-	if ((arg & MMC_TRIM_ARGS) && (card->eg_boundary) && (nr > rem)) {
+	if ((arg & MMC_TRIM_OR_DISCARD_ARGS) && card->eg_boundary && nr > rem) {
 		err = mmc_do_erase(card, from, from + rem - 1, arg);
 		from += rem;
 		if ((err) || (to <= from))

include/linux/mmc/mmc.h

@@ -451,7 +451,7 @@ static inline bool mmc_ready_for_data(u32 status)
 #define MMC_SECURE_TRIM1_ARG		0x80000001
 #define MMC_SECURE_TRIM2_ARG		0x80008000
 #define MMC_SECURE_ARGS			0x80000000
-#define MMC_TRIM_ARGS			0x00008001
+#define MMC_TRIM_OR_DISCARD_ARGS	0x00008003
 
 #define mmc_driver_type_mask(n)		(1 << (n))