mtd: rawnand: Provide a helper to get chip->data_buf

We plan to move cache related fields to a pagecache struct in nand_chip
but some drivers access ->pagebuf directly to invalidate the cache
before they start using ->data_buf.

Let's provide an helper that returns a pointer to ->data_buf after
invalidating the cache.

Signed-off-by: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Frieder Schrempf <frieder.schrempf@kontron.de>

diff --git a/drivers/mtd/nand/raw/brcmnand/brcmnand.c b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
index 482c6f0..ce0b8ff 100644 (file)
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -1676,11 +1676,8 @@ static int brcmstb_nand_verify_erased_page(struct mtd_info *mtd,
        int page = addr >> chip->page_shift;
        int ret;
 
-       if (!buf) {
-               buf = chip->data_buf;
-               /* Invalidate page cache */
-               chip->pagebuf = -1;
-       }
+       if (!buf)
+               buf = nand_get_data_buf(chip);
 
        sas = mtd->oobsize / chip->ecc.steps;
 

diff --git a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
index bcf5328..df7071e 100644 (file)
--- a/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
+++ b/drivers/mtd/nand/raw/gpmi-nand/gpmi-nand.c
@@ -1602,7 +1602,7 @@ static int mx23_check_transcription_stamp(struct gpmi_nand_data *this)
        unsigned int search_area_size_in_strides;
        unsigned int stride;
        unsigned int page;
-       uint8_t *buffer = chip->data_buf;
+       u8 *buffer = nand_get_data_buf(chip);
        int saved_chip_number;
        int found_an_ncb_fingerprint = false;
 
@@ -1664,7 +1664,7 @@ static int mx23_write_transcription_stamp(struct gpmi_nand_data *this)
        unsigned int block;
        unsigned int stride;
        unsigned int page;
-       uint8_t      *buffer = chip->data_buf;
+       u8 *buffer = nand_get_data_buf(chip);
        int saved_chip_number;
        int status;
 

diff --git a/drivers/mtd/nand/raw/marvell_nand.c b/drivers/mtd/nand/raw/marvell_nand.c
index f38e5c1..e81d401 100644 (file)
--- a/drivers/mtd/nand/raw/marvell_nand.c
+++ b/drivers/mtd/nand/raw/marvell_nand.c
@@ -1083,12 +1083,11 @@ static int marvell_nfc_hw_ecc_hmg_read_page(struct nand_chip *chip, u8 *buf,
  */
 static int marvell_nfc_hw_ecc_hmg_read_oob_raw(struct nand_chip *chip, int page)
 {
-       /* Invalidate page cache */
-       chip->pagebuf = -1;
+       u8 *buf = nand_get_data_buf(chip);
 
        marvell_nfc_select_target(chip, chip->cur_cs);
-       return marvell_nfc_hw_ecc_hmg_do_read_page(chip, chip->data_buf,
-                                                  chip->oob_poi, true, page);
+       return marvell_nfc_hw_ecc_hmg_do_read_page(chip, buf, chip->oob_poi,
+                                                  true, page);
 }
 
 /* Hamming write helpers */
@@ -1179,15 +1178,13 @@ static int marvell_nfc_hw_ecc_hmg_write_oob_raw(struct nand_chip *chip,
                                                int page)
 {
        struct mtd_info *mtd = nand_to_mtd(chip);
+       u8 *buf = nand_get_data_buf(chip);
 
-       /* Invalidate page cache */
-       chip->pagebuf = -1;
-
-       memset(chip->data_buf, 0xFF, mtd->writesize);
+       memset(buf, 0xFF, mtd->writesize);
 
        marvell_nfc_select_target(chip, chip->cur_cs);
-       return marvell_nfc_hw_ecc_hmg_do_write_page(chip, chip->data_buf,
-                                                   chip->oob_poi, true, page);
+       return marvell_nfc_hw_ecc_hmg_do_write_page(chip, buf, chip->oob_poi,
+                                                   true, page);
 }
 
 /* BCH read helpers */
@@ -1434,18 +1431,16 @@ static int marvell_nfc_hw_ecc_bch_read_page(struct nand_chip *chip,
 
 static int marvell_nfc_hw_ecc_bch_read_oob_raw(struct nand_chip *chip, int page)
 {
-       /* Invalidate page cache */
-       chip->pagebuf = -1;
+       u8 *buf = nand_get_data_buf(chip);
 
-       return chip->ecc.read_page_raw(chip, chip->data_buf, true, page);
+       return chip->ecc.read_page_raw(chip, buf, true, page);
 }
 
 static int marvell_nfc_hw_ecc_bch_read_oob(struct nand_chip *chip, int page)
 {
-       /* Invalidate page cache */
-       chip->pagebuf = -1;
+       u8 *buf = nand_get_data_buf(chip);
 
-       return chip->ecc.read_page(chip, chip->data_buf, true, page);
+       return chip->ecc.read_page(chip, buf, true, page);
 }
 
 /* BCH write helpers */
@@ -1619,25 +1614,21 @@ static int marvell_nfc_hw_ecc_bch_write_oob_raw(struct nand_chip *chip,
                                                int page)
 {
        struct mtd_info *mtd = nand_to_mtd(chip);
+       u8 *buf = nand_get_data_buf(chip);
 
-       /* Invalidate page cache */
-       chip->pagebuf = -1;
-
-       memset(chip->data_buf, 0xFF, mtd->writesize);
+       memset(buf, 0xFF, mtd->writesize);
 
-       return chip->ecc.write_page_raw(chip, chip->data_buf, true, page);
+       return chip->ecc.write_page_raw(chip, buf, true, page);
 }
 
 static int marvell_nfc_hw_ecc_bch_write_oob(struct nand_chip *chip, int page)
 {
        struct mtd_info *mtd = nand_to_mtd(chip);
+       u8 *buf = nand_get_data_buf(chip);
 
-       /* Invalidate page cache */
-       chip->pagebuf = -1;
-
-       memset(chip->data_buf, 0xFF, mtd->writesize);
+       memset(buf, 0xFF, mtd->writesize);
 
-       return chip->ecc.write_page(chip, chip->data_buf, true, page);
+       return chip->ecc.write_page(chip, buf, true, page);
 }
 
 /* NAND framework ->exec_op() hooks and related helpers */

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 071a0c6..fe8119c 100644 (file)
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -4004,10 +4004,9 @@ static int nand_do_write_ops(struct nand_chip *chip, loff_t to,
                                         __func__, buf);
                        if (part_pagewr)
                                bytes = min_t(int, bytes - column, writelen);
-                       chip->pagebuf = -1;
-                       memset(chip->data_buf, 0xff, mtd->writesize);
-                       memcpy(&chip->data_buf[column], buf, bytes);
-                       wbuf = chip->data_buf;
+                       wbuf = nand_get_data_buf(chip);
+                       memset(wbuf, 0xff, mtd->writesize);
+                       memcpy(&wbuf[column], buf, bytes);
                }
 
                if (unlikely(oob)) {

diff --git a/drivers/mtd/nand/raw/nand_bbt.c b/drivers/mtd/nand/raw/nand_bbt.c
index 19a2b56..fff8036 100644 (file)
--- a/drivers/mtd/nand/raw/nand_bbt.c
+++ b/drivers/mtd/nand/raw/nand_bbt.c
@@ -901,7 +901,9 @@ static int write_bbt(struct nand_chip *this, uint8_t *buf,
 static inline int nand_memory_bbt(struct nand_chip *this,
                                  struct nand_bbt_descr *bd)
 {
-       return create_bbt(this, this->data_buf, bd, -1);
+       u8 *pagebuf = nand_get_data_buf(this);
+
+       return create_bbt(this, pagebuf, bd, -1);
 }
 
 /**

diff --git a/drivers/mtd/nand/raw/qcom_nandc.c b/drivers/mtd/nand/raw/qcom_nandc.c
index 920e737..6ead55e 100644 (file)
--- a/drivers/mtd/nand/raw/qcom_nandc.c
+++ b/drivers/mtd/nand/raw/qcom_nandc.c
@@ -1680,14 +1680,12 @@ check_for_erased_page(struct qcom_nand_host *host, u8 *data_buf,
        u8 *cw_data_buf, *cw_oob_buf;
        int cw, data_size, oob_size, ret = 0;
 
-       if (!data_buf) {
-               data_buf = chip->data_buf;
-               chip->pagebuf = -1;
-       }
+       if (!data_buf)
+               data_buf = nand_get_data_buf(chip);
 
        if (!oob_buf) {
+               nand_get_data_buf(chip);
                oob_buf = chip->oob_poi;
-               chip->pagebuf = -1;
        }
 
        for_each_set_bit(cw, &uncorrectable_cws, ecc->steps) {

diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
index 4282bc4..d206819 100644 (file)
--- a/drivers/mtd/nand/raw/sunxi_nand.c
+++ b/drivers/mtd/nand/raw/sunxi_nand.c
@@ -1313,20 +1313,19 @@ pio_fallback:
 
 static int sunxi_nfc_hw_ecc_read_oob(struct nand_chip *nand, int page)
 {
-       nand->pagebuf = -1;
+       u8 *buf = nand_get_data_buf(nand);
 
-       return nand->ecc.read_page(nand, nand->data_buf, 1, page);
+       return nand->ecc.read_page(nand, buf, 1, page);
 }
 
 static int sunxi_nfc_hw_ecc_write_oob(struct nand_chip *nand, int page)
 {
        struct mtd_info *mtd = nand_to_mtd(nand);
+       u8 *buf = nand_get_data_buf(nand);
        int ret;
 
-       nand->pagebuf = -1;
-
-       memset(nand->data_buf, 0xff, mtd->writesize);
-       ret = nand->ecc.write_page(nand, nand->data_buf, 1, page);
+       memset(buf, 0xff, mtd->writesize);
+       ret = nand->ecc.write_page(nand, buf, 1, page);
        if (ret)
                return ret;
 

diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 58887cb..253f994 100644 (file)
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -1350,4 +1350,25 @@ int nand_gpio_waitrdy(struct nand_chip *chip, struct gpio_desc *gpiod,
 void nand_select_target(struct nand_chip *chip, unsigned int cs);
 void nand_deselect_target(struct nand_chip *chip);
 
+/**
+ * nand_get_data_buf() - Get the internal page buffer
+ * @chip: NAND chip object
+ *
+ * Returns the pre-allocated page buffer after invalidating the cache. This
+ * function should be used by drivers that do not want to allocate their own
+ * bounce buffer and still need such a buffer for specific operations (most
+ * commonly when reading OOB data only).
+ *
+ * Be careful to never call this function in the write/write_oob path, because
+ * the core may have placed the data to be written out in this buffer.
+ *
+ * Return: pointer to the page cache buffer
+ */
+static inline void *nand_get_data_buf(struct nand_chip *chip)
+{
+       chip->pagebuf = -1;
+
+       return chip->data_buf;
+}
+
 #endif /* __LINUX_MTD_RAWNAND_H */