[PATCH v2 31/32] mtd: rawnand: do not export nand_scan_[ident|tail]() anymore

From: Miquel Raynal
Date: Tue Jul 03 2018 - 18:01:36 EST


Both nand_scan_ident() and nand_scan_tail() helpers used to be called
directly from controller drivers that needed to tweak some ECC-related
parameters before nand_scan_tail(). This separation prevented dynamic
allocations during the phase of NAND identification, which was
inconvenient.

All controller drivers have been moved to use nand_scan(), in
conjunction with the chip->ecc.[attach|detach]_chip() hooks that
actually do the required tweaking sequence between both ident/tail
calls, allowing programmers to use dynamic allocation as they need all
across the scanning sequence.

Signed-off-by: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
---
drivers/mtd/nand/raw/nand_base.c | 59 ++++++++++++++++++++++++++++++++--------
include/linux/mtd/rawnand.h | 11 ++------
2 files changed, 50 insertions(+), 20 deletions(-)

diff --git a/drivers/mtd/nand/raw/nand_base.c b/drivers/mtd/nand/raw/nand_base.c
index 97a74d48b0cf..9b8777e325da 100644
--- a/drivers/mtd/nand/raw/nand_base.c
+++ b/drivers/mtd/nand/raw/nand_base.c
@@ -5120,6 +5120,7 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)
{
struct mtd_info *mtd = nand_to_mtd(chip);
struct nand_onfi_params *p;
+ char *model;
char id[4];
int i, ret, val;

@@ -5194,8 +5195,15 @@ static int nand_flash_detect_onfi(struct nand_chip *chip)

sanitize_string(p->manufacturer, sizeof(p->manufacturer));
sanitize_string(p->model, sizeof(p->model));
- strncpy(chip->parameters.model, p->model,
- sizeof(chip->parameters.model) - 1);
+ model = kmemdup(p->model, sizeof(p->model), GFP_KERNEL);
+ if (!model) {
+ ret = -ENOMEM;
+ goto free_onfi_param_page;
+ }
+
+ chip->parameters.model = model;
+ if (!mtd->name)
+ mtd->name = chip->parameters.model;

mtd->writesize = le32_to_cpu(p->byte_per_page);

@@ -5275,6 +5283,7 @@ static int nand_flash_detect_jedec(struct nand_chip *chip)
struct nand_jedec_params *p;
struct jedec_ecc_info *ecc;
int jedec_version = 0;
+ char *model;
char id[5];
int i, val, ret;

@@ -5325,8 +5334,16 @@ static int nand_flash_detect_jedec(struct nand_chip *chip)

sanitize_string(p->manufacturer, sizeof(p->manufacturer));
sanitize_string(p->model, sizeof(p->model));
- strncpy(chip->parameters.model, p->model,
- sizeof(chip->parameters.model) - 1);
+ model = kzalloc(sizeof(p->model), GFP_KERNEL);
+ if (!p) {
+ ret = -ENOMEM;
+ goto free_jedec_param_page;
+ }
+
+ strncpy(model, p->model, sizeof(model) - 1);
+ chip->parameters.model = model;
+ if (!mtd->name)
+ mtd->name = chip->parameters.model;

mtd->writesize = le32_to_cpu(p->byte_per_page);

@@ -5893,7 +5910,7 @@ static int nand_dt_init(struct nand_chip *chip)
}

/**
- * nand_scan_ident - [NAND Interface] Scan for the NAND device
+ * nand_scan_ident - Scan for the NAND device
* @mtd: MTD device structure
* @maxchips: number of chips to scan for
* @table: alternative NAND ID table
@@ -5901,9 +5918,13 @@ static int nand_dt_init(struct nand_chip *chip)
* This is the first phase of the normal nand_scan() function. It reads the
* flash ID and sets up MTD fields accordingly.
*
+ * This helper used to be called directly from controller drivers that needed
+ * to tweak some ECC-related parameters before nand_scan_tail(). This separation
+ * prevented dynamic allocations during this phase which was unconvenient and
+ * as been banned for the benefit of the ->init_ecc()/cleanup_ecc() hooks.
*/
-int nand_scan_ident(struct mtd_info *mtd, int maxchips,
- struct nand_flash_dev *table)
+static int nand_scan_ident(struct mtd_info *mtd, int maxchips,
+ struct nand_flash_dev *table)
{
int i, nand_maf_id, nand_dev_id;
struct nand_chip *chip = mtd_to_nand(mtd);
@@ -5977,7 +5998,11 @@ int nand_scan_ident(struct mtd_info *mtd, int maxchips,

return 0;
}
-EXPORT_SYMBOL(nand_scan_ident);
+
+static void nand_scan_ident_cleanup(struct nand_chip *chip)
+{
+ kfree(chip->parameters.model);
+}

static int nand_set_ecc_soft_ops(struct mtd_info *mtd)
{
@@ -6354,14 +6379,14 @@ static bool nand_ecc_strength_good(struct mtd_info *mtd)
}

/**
- * nand_scan_tail - [NAND Interface] Scan for the NAND device
+ * nand_scan_tail - Scan for the NAND device
* @mtd: MTD device structure
*
* This is the second phase of the normal nand_scan() function. It fills out
* all the uninitialized function pointers with the defaults and scans for a
* bad block table if appropriate.
*/
-int nand_scan_tail(struct mtd_info *mtd)
+static int nand_scan_tail(struct mtd_info *mtd)
{
struct nand_chip *chip = mtd_to_nand(mtd);
struct nand_ecc_ctrl *ecc = &chip->ecc;
@@ -6685,7 +6710,6 @@ int nand_scan_tail(struct mtd_info *mtd)

return ret;
}
-EXPORT_SYMBOL(nand_scan_tail);

/*
* is_module_text_address() isn't exported, and it's mostly a pointless
@@ -6722,12 +6746,20 @@ int nand_scan_with_ids(struct mtd_info *mtd, int maxchips,
if (chip->controller->attach_chip) {
ret = chip->controller->attach_chip(chip);
if (ret)
- return ret;
+ goto cleanup_ident;
}

ret = nand_scan_tail(mtd);
+ if (ret)
+ goto detach_chip;
+
+ return 0;
+
+detach_chip:
if (ret && chip->controller->detach_chip)
chip->controller->detach_chip(chip);
+cleanup_ident:
+ nand_scan_ident_cleanup(chip);

return ret;
}
@@ -6760,6 +6792,9 @@ void nand_cleanup(struct nand_chip *chip)
/* Free controller specific allocations after chip identification */
if (chip->controller->detach_chip)
chip->controller->detach_chip(chip);
+
+ /* Free identification phase allocations */
+ nand_scan_ident_cleanup(chip);
}

EXPORT_SYMBOL_GPL(nand_cleanup);
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 81654211e520..61b8e9a7e870 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -37,14 +37,9 @@ static inline int nand_scan(struct mtd_info *mtd, int max_chips)
}

/*
- * Separate phases of nand_scan(), allowing board driver to intervene
- * and override command or ECC setup according to flash type.
+ * Unregister the MTD device and free resources held by the NAND device, must be
+ * called on error after a successful nand_scan().
*/
-int nand_scan_ident(struct mtd_info *mtd, int max_chips,
- struct nand_flash_dev *table);
-int nand_scan_tail(struct mtd_info *mtd);
-
-/* Unregister the MTD device and free resources held by the NAND device */
void nand_release(struct mtd_info *mtd);

/* Internal helper for board drivers which need to override command function */
@@ -488,7 +483,7 @@ struct onfi_params {
*/
struct nand_parameters {
/* Generic parameters */
- char model[100];
+ const char *model;
bool supports_set_get_features;
DECLARE_BITMAP(set_feature_list, ONFI_FEATURE_NUMBER);
DECLARE_BITMAP(get_feature_list, ONFI_FEATURE_NUMBER);
--
2.14.1