mtd: nand: fix drivers abusing mtd->priv

The ->priv field of the mtd_info object attached to a nand_chip device
should point to the nand_chip device. The pxa and cafe drivers are
assigning this field their own private structure, which works fine as long
as the nand_chip field is the first one in the driver private struct but
seems a bit fragile.
Fix that by setting mtd->priv to point the nand_chip field and assigning
chip->priv to the private structure head.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 22 insertions, 12 deletions

diff --git a/drivers/mtd/nand/cafe_nand.c b/drivers/mtd/nand/cafe_nand.c
index 9de78d2a2eb1..cce3ac4939b6 100644
--- a/drivers/mtd/nand/cafe_nand.c
+++ b/drivers/mtd/nand/cafe_nand.c
@@ -101,7 +101,8 @@ static const char *part_probes[] = { "cmdlinepart", "RedBoot", NULL };
 
 static int cafe_device_ready(struct mtd_info *mtd)
 {
-	struct cafe_priv *cafe = mtd->priv;
+	struct nand_chip *chip = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 	int result = !!(cafe_readl(cafe, NAND_STATUS) & 0x40000000);
 	uint32_t irqs = cafe_readl(cafe, NAND_IRQ);
 
@@ -117,7 +118,8 @@ static int cafe_device_ready(struct mtd_info *mtd)
 
 static void cafe_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
 {
-	struct cafe_priv *cafe = mtd->priv;
+	struct nand_chip *chip = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 
 	if (usedma)
 		memcpy(cafe->dmabuf + cafe->datalen, buf, len);
@@ -132,7 +134,8 @@ static void cafe_write_buf(struct mtd_info *mtd, const uint8_t *buf, int len)
 
 static void cafe_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
 {
-	struct cafe_priv *cafe = mtd->priv;
+	struct nand_chip *chip = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 
 	if (usedma)
 		memcpy(buf, cafe->dmabuf + cafe->datalen, len);
@@ -146,7 +149,8 @@ static void cafe_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
 
 static uint8_t cafe_read_byte(struct mtd_info *mtd)
 {
-	struct cafe_priv *cafe = mtd->priv;
+	struct nand_chip *chip = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 	uint8_t d;
 
 	cafe_read_buf(mtd, &d, 1);
@@ -158,7 +162,8 @@ static uint8_t cafe_read_byte(struct mtd_info *mtd)
 static void cafe_nand_cmdfunc(struct mtd_info *mtd, unsigned command,
 			      int column, int page_addr)
 {
-	struct cafe_priv *cafe = mtd->priv;
+	struct nand_chip *chip = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 	int adrbytes = 0;
 	uint32_t ctl1;
 	uint32_t doneint = 0x80000000;
@@ -313,7 +318,8 @@ static void cafe_nand_cmdfunc(struct mtd_info *mtd, unsigned command,
 
 static void cafe_select_chip(struct mtd_info *mtd, int chipnr)
 {
-	struct cafe_priv *cafe = mtd->priv;
+	struct nand_chip *chip = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 
 	cafe_dev_dbg(&cafe->pdev->dev, "select_chip %d\n", chipnr);
 
@@ -328,7 +334,8 @@ static void cafe_select_chip(struct mtd_info *mtd, int chipnr)
 static irqreturn_t cafe_nand_interrupt(int irq, void *id)
 {
 	struct mtd_info *mtd = id;
-	struct cafe_priv *cafe = mtd->priv;
+	struct nand_chip *chip = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 	uint32_t irqs = cafe_readl(cafe, NAND_IRQ);
 	cafe_writel(cafe, irqs & ~0x90000000, NAND_IRQ);
 	if (!irqs)
@@ -377,7 +384,7 @@ static int cafe_nand_read_oob(struct mtd_info *mtd, struct nand_chip *chip,
 static int cafe_nand_read_page(struct mtd_info *mtd, struct nand_chip *chip,
 			       uint8_t *buf, int oob_required, int page)
 {
-	struct cafe_priv *cafe = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 	unsigned int max_bitflips = 0;
 
 	cafe_dev_dbg(&cafe->pdev->dev, "ECC result %08x SYN1,2 %08x\n",
@@ -519,7 +526,7 @@ static int cafe_nand_write_page_lowlevel(struct mtd_info *mtd,
 					  const uint8_t *buf, int oob_required,
 					  int page)
 {
-	struct cafe_priv *cafe = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 
 	chip->write_buf(mtd, buf, mtd->writesize);
 	chip->write_buf(mtd, chip->oob_poi, mtd->oobsize);
@@ -604,7 +611,8 @@ static int cafe_nand_probe(struct pci_dev *pdev,
 	cafe = (void *)(&mtd[1]);
 
 	mtd->dev.parent = &pdev->dev;
-	mtd->priv = cafe;
+	mtd->priv = &cafe->nand;
+	cafe->nand.priv = cafe;
 
 	cafe->pdev = pdev;
 	cafe->mmio = pci_iomap(pdev, 0, 0);
@@ -792,7 +800,8 @@ static int cafe_nand_probe(struct pci_dev *pdev,
 static void cafe_nand_remove(struct pci_dev *pdev)
 {
 	struct mtd_info *mtd = pci_get_drvdata(pdev);
-	struct cafe_priv *cafe = mtd->priv;
+	struct nand_chip *chip = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 
 	/* Disable NAND IRQ in global IRQ mask register */
 	cafe_writel(cafe, ~1 & cafe_readl(cafe, GLOBAL_IRQ_MASK), GLOBAL_IRQ_MASK);
@@ -819,7 +828,8 @@ static int cafe_nand_resume(struct pci_dev *pdev)
 {
 	uint32_t ctrl;
 	struct mtd_info *mtd = pci_get_drvdata(pdev);
-	struct cafe_priv *cafe = mtd->priv;
+	struct nand_chip *chip = mtd->priv;
+	struct cafe_priv *cafe = chip->priv;
 
        /* Start off by resetting the NAND controller completely */
 	cafe_writel(cafe, 1, NAND_RESET);