[RFC 03/12] mtd: nand: use a static data_interface in the nand_chip structure
Miquel Raynal
miquel.raynal at free-electrons.com
Wed Oct 18 07:36:20 PDT 2017
Change the data_interface field from the nand_chip structure, convert
the pointer to a static structure.
Also remove the nand_get_default_data_interface() function that become
useless and rename the onfi_init_data_interface() by
nand_fill_data_interface(), which is a more appropriate name because
applied timings are ONFI, no matter if the NAND actually is one.
This is needed before passing to ->exec_op() to avoid any race that
could lead to a panic (null pointer dereference) on the initialization
of the timings structure that will be used from the first reset
operation if the pointer to data_interface was not referenced yet.
Signed-off-by: Miquel Raynal <miquel.raynal at free-electrons.com>
---
drivers/mtd/nand/nand_base.c | 35 ++++++++++-------------------------
drivers/mtd/nand/nand_timings.c | 23 ++++++-----------------
include/linux/mtd/rawnand.h | 9 ++-------
3 files changed, 18 insertions(+), 49 deletions(-)
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index 318595c29053..bef20e06f0db 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -814,8 +814,8 @@ static void nand_ccs_delay(struct nand_chip *chip)
* Wait tCCS_min if it is correctly defined, otherwise wait 500ns
* (which should be safe for all NANDs).
*/
- if (chip->data_interface && chip->data_interface->timings.sdr.tCCS_min)
- ndelay(chip->data_interface->timings.sdr.tCCS_min / 1000);
+ if (chip->data_interface.timings.sdr.tCCS_min)
+ ndelay(chip->data_interface.timings.sdr.tCCS_min / 1000);
else
ndelay(500);
}
@@ -1107,7 +1107,6 @@ static int nand_wait(struct mtd_info *mtd, struct nand_chip *chip)
static int nand_reset_data_interface(struct nand_chip *chip, int chipnr)
{
struct mtd_info *mtd = nand_to_mtd(chip);
- const struct nand_data_interface *conf;
int ret;
if (!chip->setup_data_interface)
@@ -1127,8 +1126,8 @@ static int nand_reset_data_interface(struct nand_chip *chip, int chipnr)
* timings to timing mode 0.
*/
- conf = nand_get_default_data_interface();
- ret = chip->setup_data_interface(mtd, chipnr, conf);
+ nand_fill_data_interface(chip, 0);
+ ret = chip->setup_data_interface(mtd, chipnr, &chip->data_interface);
if (ret)
pr_err("Failed to configure data interface to SDR timing mode 0\n");
@@ -1153,7 +1152,7 @@ static int nand_setup_data_interface(struct nand_chip *chip, int chipnr)
struct mtd_info *mtd = nand_to_mtd(chip);
int ret;
- if (!chip->setup_data_interface || !chip->data_interface)
+ if (!chip->setup_data_interface)
return 0;
/*
@@ -1174,7 +1173,7 @@ static int nand_setup_data_interface(struct nand_chip *chip, int chipnr)
goto err;
}
- ret = chip->setup_data_interface(mtd, chipnr, chip->data_interface);
+ ret = chip->setup_data_interface(mtd, chipnr, &chip->data_interface);
err:
return ret;
}
@@ -1214,21 +1213,16 @@ static int nand_init_data_interface(struct nand_chip *chip)
modes = GENMASK(chip->onfi_timing_mode_default, 0);
}
- chip->data_interface = kzalloc(sizeof(*chip->data_interface),
- GFP_KERNEL);
- if (!chip->data_interface)
- return -ENOMEM;
for (mode = fls(modes) - 1; mode >= 0; mode--) {
- ret = onfi_init_data_interface(chip, chip->data_interface,
- NAND_SDR_IFACE, mode);
+ ret = nand_fill_data_interface(chip, mode);
if (ret)
continue;
/* Pass -1 to only */
ret = chip->setup_data_interface(mtd,
NAND_DATA_IFACE_CHECK_ONLY,
- chip->data_interface);
+ &chip->data_interface);
if (!ret) {
chip->onfi_timing_mode_default = mode;
break;
@@ -1238,11 +1232,6 @@ static int nand_init_data_interface(struct nand_chip *chip)
return 0;
}
-static void nand_release_data_interface(struct nand_chip *chip)
-{
- kfree(chip->data_interface);
-}
-
/**
* nand_read_page_op - Do a READ PAGE operation
* @chip: The NAND chip
@@ -5567,7 +5556,7 @@ int nand_scan_tail(struct mtd_info *mtd)
chip->select_chip(mtd, -1);
if (ret)
- goto err_nand_data_iface_cleanup;
+ goto err_nand_manuf_cleanup;
}
/* Check, if we should skip the bad block table scan */
@@ -5577,12 +5566,10 @@ int nand_scan_tail(struct mtd_info *mtd)
/* Build bad block table */
ret = chip->scan_bbt(mtd);
if (ret)
- goto err_nand_data_iface_cleanup;
+ goto err_nand_manuf_cleanup;
return 0;
-err_nand_data_iface_cleanup:
- nand_release_data_interface(chip);
err_nand_manuf_cleanup:
nand_manufacturer_cleanup(chip);
@@ -5641,8 +5628,6 @@ void nand_cleanup(struct nand_chip *chip)
chip->ecc.algo == NAND_ECC_BCH)
nand_bch_free((struct nand_bch_control *)chip->ecc.priv);
- nand_release_data_interface(chip);
-
/* Free bad block table memory */
kfree(chip->bbt);
if (!(chip->options & NAND_OWN_BUFFERS) && chip->buffers) {
diff --git a/drivers/mtd/nand/nand_timings.c b/drivers/mtd/nand/nand_timings.c
index 5d1533bcc5bd..745b6404c901 100644
--- a/drivers/mtd/nand/nand_timings.c
+++ b/drivers/mtd/nand/nand_timings.c
@@ -283,17 +283,17 @@ const struct nand_sdr_timings *onfi_async_timing_mode_to_sdr_timings(int mode)
EXPORT_SYMBOL(onfi_async_timing_mode_to_sdr_timings);
/**
- * onfi_init_data_interface - [NAND Interface] Initialize a data interface from
+ * nand_fill_data_interface - [NAND Interface] Initialize a data interface from
* given ONFI mode
* @iface: The data interface to be initialized
* @mode: The ONFI timing mode
*/
-int onfi_init_data_interface(struct nand_chip *chip,
- struct nand_data_interface *iface,
- enum nand_data_interface_type type,
+int nand_fill_data_interface(struct nand_chip *chip,
int timing_mode)
{
- if (type != NAND_SDR_IFACE)
+ struct nand_data_interface *iface = &chip->data_interface;
+
+ if (iface->type != NAND_SDR_IFACE)
return -EINVAL;
if (timing_mode < 0 || timing_mode >= ARRAY_SIZE(onfi_sdr_timings))
@@ -321,15 +321,4 @@ int onfi_init_data_interface(struct nand_chip *chip,
return 0;
}
-EXPORT_SYMBOL(onfi_init_data_interface);
-
-/**
- * nand_get_default_data_interface - [NAND Interface] Retrieve NAND
- * data interface for mode 0. This is used as default timing after
- * reset.
- */
-const struct nand_data_interface *nand_get_default_data_interface(void)
-{
- return &onfi_sdr_timings[0];
-}
-EXPORT_SYMBOL(nand_get_default_data_interface);
+EXPORT_SYMBOL(nand_fill_data_interface);
diff --git a/include/linux/mtd/rawnand.h b/include/linux/mtd/rawnand.h
index 04f4cfbe6c09..1acc26ed0e91 100644
--- a/include/linux/mtd/rawnand.h
+++ b/include/linux/mtd/rawnand.h
@@ -917,7 +917,7 @@ struct nand_chip {
u16 max_bb_per_die;
u32 blocks_per_die;
- struct nand_data_interface *data_interface;
+ struct nand_data_interface data_interface;
int read_retries;
@@ -1214,10 +1214,7 @@ static inline int onfi_get_sync_timing_mode(struct nand_chip *chip)
return le16_to_cpu(chip->onfi_params.src_sync_timing_mode);
}
-int onfi_init_data_interface(struct nand_chip *chip,
- struct nand_data_interface *iface,
- enum nand_data_interface_type type,
- int timing_mode);
+int nand_fill_data_interface(struct nand_chip *chip, int timing_mode);
/*
* Check if it is a SLC nand.
@@ -1258,8 +1255,6 @@ static inline int jedec_feature(struct nand_chip *chip)
/* get timing characteristics from ONFI timing mode. */
const struct nand_sdr_timings *onfi_async_timing_mode_to_sdr_timings(int mode);
-/* get data interface from ONFI timing mode 0, used after reset. */
-const struct nand_data_interface *nand_get_default_data_interface(void);
int nand_check_erased_ecc_chunk(void *data, int datalen,
void *ecc, int ecclen,
--
2.11.0
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