mtd: nand: fsl_ifc: Fix eccstat array overflow for IFC ver >= 2.0.0

commit 843c3a59997f18060848b8632607dd04781b52d1 upstream.

Number of ECC status registers i.e. (ECCSTATx) has been increased in IFC
version 2.0.0 due to increase in SRAM size. This is causing eccstat
array to over flow.

So, replace eccstat array with u32 variable to make it fail-safe and
independent of number of ECC status registers or SRAM size.

Fixes: bccb06c353af ("mtd: nand: ifc: update bufnum mask for ver >= 2.0.0")
Cc: stable@vger.kernel.org # 3.18+
Signed-off-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
Signed-off-by: Jagdish Gediya <jagdish.gediya@nxp.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/mtd/nand/fsl_ifc_nand.c b/drivers/mtd/nand/fsl_ifc_nand.c
index 8e0b4543b514833abc5a7f8bc5b079a2e491bc14..398e8408a937b9dd139883795cd7afa8d8b81939 100644 (file)
--- a/drivers/mtd/nand/fsl_ifc_nand.c
+++ b/drivers/mtd/nand/fsl_ifc_nand.c
@@ -173,14 +173,9 @@ static void set_addr(struct mtd_info *mtd, int column, int page_addr, int oob)
 
 /* returns nonzero if entire page is blank */
 static int check_read_ecc(struct mtd_info *mtd, struct fsl_ifc_ctrl *ctrl,
-                         u32 *eccstat, unsigned int bufnum)
+                         u32 eccstat, unsigned int bufnum)
 {
-       u32 reg = eccstat[bufnum / 4];
-       int errors;
-
-       errors = (reg >> ((3 - bufnum % 4) * 8)) & 15;
-
-       return errors;
+       return  (eccstat >> ((3 - bufnum % 4) * 8)) & 15;
 }
 
 /*
@@ -193,7 +188,7 @@ static void fsl_ifc_run_command(struct mtd_info *mtd)
        struct fsl_ifc_ctrl *ctrl = priv->ctrl;
        struct fsl_ifc_nand_ctrl *nctrl = ifc_nand_ctrl;
        struct fsl_ifc_runtime __iomem *ifc = ctrl->rregs;
-       u32 eccstat[4];
+       u32 eccstat;
        int i;
 
        /* set the chip select for NAND Transaction */
@@ -228,8 +223,8 @@ static void fsl_ifc_run_command(struct mtd_info *mtd)
        if (nctrl->eccread) {
                int errors;
                int bufnum = nctrl->page & priv->bufnum_mask;
-               int sector = bufnum * chip->ecc.steps;
-               int sector_end = sector + chip->ecc.steps - 1;
+               int sector_start = bufnum * chip->ecc.steps;
+               int sector_end = sector_start + chip->ecc.steps - 1;
                __be32 *eccstat_regs;
 
                if (ctrl->version >= FSL_IFC_VERSION_2_0_0)
@@ -237,10 +232,12 @@ static void fsl_ifc_run_command(struct mtd_info *mtd)
                else
                        eccstat_regs = ifc->ifc_nand.v1_nand_eccstat;
 
-               for (i = sector / 4; i <= sector_end / 4; i++)
-                       eccstat[i] = ifc_in32(&eccstat_regs[i]);
+               eccstat = ifc_in32(&eccstat_regs[sector_start / 4]);
+
+               for (i = sector_start; i <= sector_end; i++) {
+                       if (i != sector_start && !(i % 4))
+                               eccstat = ifc_in32(&eccstat_regs[i / 4]);
 
-               for (i = sector; i <= sector_end; i++) {
                        errors = check_read_ecc(mtd, ctrl, eccstat, i);
 
                        if (errors == 15) {