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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tokunori Ikegami <ikegami.t@gmail.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>
Subject: [PATCH 4.19 286/287] mtd: cfi_cmdset_0002: Move and rename chip_check/chip_ready/chip_good_for_write
Date:   Mon, 13 Jun 2022 12:11:50 +0200
Message-Id: <20220613094932.665758427@linuxfoundation.org>
In-Reply-To: <20220613094923.832156175@linuxfoundation.org>
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From: Tokunori Ikegami <ikegami.t@gmail.com>

commit 083084df578a8bdb18334f69e7b32d690aaa3247 upstream.

This is a preparation patch for the S29GL064N buffer writes fix. There
is no functional change.

Link: https://lore.kernel.org/r/b687c259-6413-26c9-d4c9-b3afa69ea124@pengutronix.de/
Fixes: dfeae1073583("mtd: cfi_cmdset_0002: Change write buffer to check correct value")
Signed-off-by: Tokunori Ikegami <ikegami.t@gmail.com>
Cc: stable@vger.kernel.org
Acked-by: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20220323170458.5608-2-ikegami.t@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/mtd/chips/cfi_cmdset_0002.c |   77 ++++++++++++++----------------------
 1 file changed, 32 insertions(+), 45 deletions(-)

--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -731,50 +731,34 @@ static struct mtd_info *cfi_amdstd_setup
 }
 
 /*
- * Return true if the chip is ready.
+ * Return true if the chip is ready and has the correct value.
  *
  * Ready is one of: read mode, query mode, erase-suspend-read mode (in any
  * non-suspended sector) and is indicated by no toggle bits toggling.
  *
+ * Error are indicated by toggling bits or bits held with the wrong value,
+ * or with bits toggling.
+ *
  * Note that anything more complicated than checking if no bits are toggling
  * (including checking DQ5 for an error status) is tricky to get working
  * correctly and is therefore not done	(particularly with interleaved chips
  * as each chip must be checked independently of the others).
  */
-static int __xipram chip_ready(struct map_info *map, unsigned long addr)
+static int __xipram chip_ready(struct map_info *map, unsigned long addr,
+			       map_word *expected)
 {
 	map_word d, t;
+	int ret;
 
 	d = map_read(map, addr);
 	t = map_read(map, addr);
 
-	return map_word_equal(map, d, t);
-}
+	ret = map_word_equal(map, d, t);
 
-/*
- * Return true if the chip is ready and has the correct value.
- *
- * Ready is one of: read mode, query mode, erase-suspend-read mode (in any
- * non-suspended sector) and it is indicated by no bits toggling.
- *
- * Error are indicated by toggling bits or bits held with the wrong value,
- * or with bits toggling.
- *
- * Note that anything more complicated than checking if no bits are toggling
- * (including checking DQ5 for an error status) is tricky to get working
- * correctly and is therefore not done	(particularly with interleaved chips
- * as each chip must be checked independently of the others).
- *
- */
-static int __xipram chip_good(struct map_info *map, unsigned long addr, map_word expected)
-{
-	map_word oldd, curd;
-
-	oldd = map_read(map, addr);
-	curd = map_read(map, addr);
+	if (!ret || !expected)
+		return ret;
 
-	return	map_word_equal(map, oldd, curd) &&
-		map_word_equal(map, curd, expected);
+	return map_word_equal(map, t, *expected);
 }
 
 static int get_chip(struct map_info *map, struct flchip *chip, unsigned long adr, int mode)
@@ -791,7 +775,7 @@ static int get_chip(struct map_info *map
 
 	case FL_STATUS:
 		for (;;) {
-			if (chip_ready(map, adr))
+			if (chip_ready(map, adr, NULL))
 				break;
 
 			if (time_after(jiffies, timeo)) {
@@ -829,7 +813,7 @@ static int get_chip(struct map_info *map
 		chip->state = FL_ERASE_SUSPENDING;
 		chip->erase_suspended = 1;
 		for (;;) {
-			if (chip_ready(map, adr))
+			if (chip_ready(map, adr, NULL))
 				break;
 
 			if (time_after(jiffies, timeo)) {
@@ -1360,7 +1344,7 @@ static int do_otp_lock(struct map_info *
 	/* wait for chip to become ready */
 	timeo = jiffies + msecs_to_jiffies(2);
 	for (;;) {
-		if (chip_ready(map, adr))
+		if (chip_ready(map, adr, NULL))
 			break;
 
 		if (time_after(jiffies, timeo)) {
@@ -1627,10 +1611,11 @@ static int __xipram do_write_oneword(str
 		}
 
 		/*
-		 * We check "time_after" and "!chip_good" before checking
-		 * "chip_good" to avoid the failure due to scheduling.
+		 * We check "time_after" and "!chip_ready" before checking
+		 * "chip_ready" to avoid the failure due to scheduling.
 		 */
-		if (time_after(jiffies, timeo) && !chip_good(map, adr, datum)) {
+		if (time_after(jiffies, timeo) &&
+		    !chip_ready(map, adr, &datum)) {
 			xip_enable(map, chip, adr);
 			printk(KERN_WARNING "MTD %s(): software timeout\n", __func__);
 			xip_disable(map, chip, adr);
@@ -1638,7 +1623,7 @@ static int __xipram do_write_oneword(str
 			break;
 		}
 
-		if (chip_good(map, adr, datum))
+		if (chip_ready(map, adr, &datum))
 			break;
 
 		/* Latency issues. Drop the lock, wait a while and retry */
@@ -1882,13 +1867,13 @@ static int __xipram do_write_buffer(stru
 		}
 
 		/*
-		 * We check "time_after" and "!chip_good" before checking "chip_good" to avoid
-		 * the failure due to scheduling.
+		 * We check "time_after" and "!chip_ready" before checking
+		 * "chip_ready" to avoid the failure due to scheduling.
 		 */
-		if (time_after(jiffies, timeo) && !chip_good(map, adr, datum))
+		if (time_after(jiffies, timeo) && !chip_ready(map, adr, &datum))
 			break;
 
-		if (chip_good(map, adr, datum)) {
+		if (chip_ready(map, adr, &datum)) {
 			xip_enable(map, chip, adr);
 			goto op_done;
 		}
@@ -2022,7 +2007,7 @@ static int cfi_amdstd_panic_wait(struct
 	 * If the driver thinks the chip is idle, and no toggle bits
 	 * are changing, then the chip is actually idle for sure.
 	 */
-	if (chip->state == FL_READY && chip_ready(map, adr))
+	if (chip->state == FL_READY && chip_ready(map, adr, NULL))
 		return 0;
 
 	/*
@@ -2039,7 +2024,7 @@ static int cfi_amdstd_panic_wait(struct
 
 		/* wait for the chip to become ready */
 		for (i = 0; i < jiffies_to_usecs(timeo); i++) {
-			if (chip_ready(map, adr))
+			if (chip_ready(map, adr, NULL))
 				return 0;
 
 			udelay(1);
@@ -2103,13 +2088,13 @@ retry:
 	map_write(map, datum, adr);
 
 	for (i = 0; i < jiffies_to_usecs(uWriteTimeout); i++) {
-		if (chip_ready(map, adr))
+		if (chip_ready(map, adr, NULL))
 			break;
 
 		udelay(1);
 	}
 
-	if (!chip_good(map, adr, datum)) {
+	if (!chip_ready(map, adr, &datum)) {
 		/* reset on all failures. */
 		map_write(map, CMD(0xF0), chip->start);
 		/* FIXME - should have reset delay before continuing */
@@ -2250,6 +2235,7 @@ static int __xipram do_erase_chip(struct
 	DECLARE_WAITQUEUE(wait, current);
 	int ret = 0;
 	int retry_cnt = 0;
+	map_word datum = map_word_ff(map);
 
 	adr = cfi->addr_unlock1;
 
@@ -2304,7 +2290,7 @@ static int __xipram do_erase_chip(struct
 			chip->erase_suspended = 0;
 		}
 
-		if (chip_good(map, adr, map_word_ff(map)))
+		if (chip_ready(map, adr, &datum))
 			break;
 
 		if (time_after(jiffies, timeo)) {
@@ -2346,6 +2332,7 @@ static int __xipram do_erase_oneblock(st
 	DECLARE_WAITQUEUE(wait, current);
 	int ret = 0;
 	int retry_cnt = 0;
+	map_word datum = map_word_ff(map);
 
 	adr += chip->start;
 
@@ -2400,7 +2387,7 @@ static int __xipram do_erase_oneblock(st
 			chip->erase_suspended = 0;
 		}
 
-		if (chip_good(map, adr, map_word_ff(map)))
+		if (chip_ready(map, adr, &datum))
 			break;
 
 		if (time_after(jiffies, timeo)) {
@@ -2593,7 +2580,7 @@ static int __maybe_unused do_ppb_xxlock(
 	 */
 	timeo = jiffies + msecs_to_jiffies(2000);	/* 2s max (un)locking */
 	for (;;) {
-		if (chip_ready(map, adr))
+		if (chip_ready(map, adr, NULL))
 			break;
 
 		if (time_after(jiffies, timeo)) {