mtd: rawnand: qcom: embed nand_controller into qcom_nand_controller

The qcom_nand_controller had a struct nand_controller *controller
pointer that was assigned to (struct nand_controller *)&nandc[1],
with the allocation oversized by sizeof(*controller) to make room.
get_qcom_nand_controller() then walked backwards from chip->controller
using sizeof()-based arithmetic to recover the enclosing nandc.

Embed the nand_controller directly into qcom_nand_controller and use
container_of() in get_qcom_nand_controller(). The header now needs
the full rawnand.h definition rather than a forward declaration.

Assisted-by: Claude:Opus-4.7
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>

diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
index b7e79b76654d908e4ee8ff832938901c9c08541f..4b80ce084d9acf6c8e84eea79ec463aa39d5eab6 100644 (file)
--- a/drivers/mtd/nand/raw/qcom_nandc.c
+++ b/drivers/mtd/nand/raw/qcom_nandc.c
@@ -128,8 +128,8 @@ static struct qcom_nand_host *to_qcom_nand_host(struct nand_chip *chip)
 static struct qcom_nand_controller *
 get_qcom_nand_controller(struct nand_chip *chip)
 {
-       return (struct qcom_nand_controller *)
-               ((u8 *)chip->controller - sizeof(struct qcom_nand_controller));
+       return container_of(chip->controller, struct qcom_nand_controller,
+                           controller);
 }
 
 static u32 nandc_read(struct qcom_nand_controller *nandc, int offset)
@@ -2034,8 +2034,8 @@ static int qcom_nandc_setup(struct qcom_nand_controller *nandc)
 {
        u32 nand_ctrl;
 
-       nand_controller_init(nandc->controller);
-       nandc->controller->ops = &qcom_nandc_ops;
+       nand_controller_init(&nandc->controller);
+       nandc->controller.ops = &qcom_nandc_ops;
 
        /* kill onenand */
        if (!nandc->props->nandc_part_of_qpic)
@@ -2175,7 +2175,7 @@ static int qcom_nand_host_init_and_register(struct qcom_nand_controller *nandc,
        chip->legacy.block_bad          = qcom_nandc_block_bad;
        chip->legacy.block_markbad      = qcom_nandc_block_markbad;
 
-       chip->controller = nandc->controller;
+       chip->controller = &nandc->controller;
        chip->options |= NAND_NO_SUBPAGE_WRITE | NAND_USES_DMA |
                         NAND_SKIP_BBTSCAN;
 
@@ -2256,21 +2256,17 @@ static int qcom_nandc_parse_dt(struct platform_device *pdev)
 static int qcom_nandc_probe(struct platform_device *pdev)
 {
        struct qcom_nand_controller *nandc;
-       struct nand_controller *controller;
        const void *dev_data;
        struct device *dev = &pdev->dev;
        struct resource *res;
        int ret;
 
-       nandc = devm_kzalloc(&pdev->dev, sizeof(*nandc) + sizeof(*controller),
-                            GFP_KERNEL);
+       nandc = devm_kzalloc(&pdev->dev, sizeof(*nandc), GFP_KERNEL);
        if (!nandc)
                return -ENOMEM;
-       controller = (struct nand_controller *)&nandc[1];
 
        platform_set_drvdata(pdev, nandc);
        nandc->dev = dev;
-       nandc->controller = controller;
 
        dev_data = of_device_get_match_data(dev);
        if (!dev_data) {

diff --git a/include/linux/mtd/nand-qpic-common.h b/include/linux/mtd/nand-qpic-common.h
index e8201d1b7cf9d0f0a5a0e07bd600362b3f0f1f67..006ca8c978a91e5399b1a048127aad8c81e3aa18 100644 (file)
--- a/include/linux/mtd/nand-qpic-common.h
+++ b/include/linux/mtd/nand-qpic-common.h
@@ -9,6 +9,8 @@
 #ifndef __MTD_NAND_QPIC_COMMON_H__
 #define __MTD_NAND_QPIC_COMMON_H__
 
+#include <linux/mtd/rawnand.h>
+
 /* NANDc reg offsets */
 #define        NAND_FLASH_CMD                  0x00
 #define        NAND_ADDR0                      0x04
@@ -394,7 +396,7 @@ struct qcom_nand_controller {
 
        const struct qcom_nandc_props *props;
 
-       struct nand_controller *controller;
+       struct nand_controller controller;
        struct qpic_spi_nand *qspi;
        struct list_head host_list;