mtd: core: Fix erase area alignment for non power of 2 erasesize
PATCH 1/1 mtd: core: Fix erase area alignment for non power of 2 erasesize
Devices as AT45DB161 DataFlash uses non power of two page size (528) while present alignment algorithm relies on erasesize being power of 2.
Fix that by introducing helper functions rounding to any multiply. Note that logic is sligthly changed to be consistent as ending address is moved forward to include also last byte meant to be erased while previous implementation moved it backward.
--- drivers/mtd/core.c | 28 ++++++++++++++++++++++------ include/linux/kernel.h | 5 +++++ 2 files changed, 27 insertions(+), 6 deletions(-)
drivers/mtd/core.c +22 -6
@@ -141,15 +141,31 @@ static struct mtd_erase_region_info *mtd_find_erase_region(struct mtd_info *mtd,return NULL ; } +static inline loff_t esize_up (loff_t x,uint32_t erasesize) +{ +uint32_t mod =DIV_ROUND_DOWN_ULL (x, erasesize); +if (mod ==0 ) +return x; +return x + erasesize - mod; +} + +static inline loff_t esize_down (loff_t x,uint32_t erasesize) +{ +uint32_t mod =DIV_ROUND_DOWN_ULL (x, erasesize); +if (mod ==0 ) +return x; +return x - mod; +} +static int mtd_erase_align (struct mtd_info *mtd,loff_t *count,loff_t *offset) {struct mtd_erase_region_info *e;loff_t ofs;if (mtd->numeraseregions ==0 ) { - ofs = *offset & ~(loff_t)(mtd->erasesize -1 ); - *count += (*offset - ofs); - *count =ALIGN (*count, mtd->erasesize); + ofs =esize_down (*offset, mtd->erasesize); + *count += *offset - ofs; + *count =esize_up (*count, mtd->erasesize); *offset = ofs;return 0 ; }
@@ -158,14 +174,14 @@ static int mtd_erase_align(struct mtd_info *mtd, loff_t *count, loff_t *offset)if (!e)return -EINVAL ; - ofs = *offset & ~(e->erasesize -1 ); - *count += (*offset - ofs); + ofs =esize_down (*offset, e->erasesize); + *count += *offset - ofs; e =mtd_find_erase_region (mtd, *offset + *count);if (!e)return -EINVAL ; - *count =ALIGN (*count, e->erasesize); + *count =esize_up (*count, e->erasesize); *offset = ofs;return 0 ;
include/linux/kernel.h +5 -0
@@ -55,6 +55,11 @@#define DIV_ROUND_UP (n,d) (((n) + (d) - 1) / (d)) +#define DIV_ROUND_DOWN_ULL (ll, d) \ + ({ unsigned long long _tmp = (ll); do_div(_tmp, d); _tmp; }) + +#define DIV_ROUND_UP_ULL (ll, d) DIV_ROUND_DOWN_ULL((ll) + (d) - 1, (d)) +#define DIV_ROUND_CLOSEST (x, divisor)( \ { \ typeof(divisor) __divisor = divisor; \
Signature · 7 lines
2.20.1 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
Sascha Hauer
AppliedQuoted 8 lines · Ladislav Michl
Devices as AT45DB161 DataFlash uses non power of two page size (528) while present alignment algorithm relies on erasesize being power of 2.
Fix that by introducing helper functions rounding to any multiply. Note that logic is sligthly changed to be consistent as ending address is moved forward to include also last byte meant to be erased while previous implementation moved it backward.
Quoted 5 lines
Signed-off-by Ladislav Michl <[email protected]>--- drivers/mtd/core.c | 28 ++++++++++++++++++++++------ include/linux/kernel.h | 5 +++++ 2 files changed, 27 insertions(+), 6 deletions(-)
Applied, thanks
Sascha
Signature · 9 lines
Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
Quoted 9 lines · Sascha Hauer
Quoted 8 lines · Ladislav Michl
Devices as AT45DB161 DataFlash uses non power of two page size (528) while present alignment algorithm relies on erasesize being power of 2.
Fix that by introducing helper functions rounding to any multiply. Note that logic is sligthly changed to be consistent as ending address is moved forward to include also last byte meant to be erased while previous implementation moved it backward.
Quoted 7 lines
Quoted 5 lines
Signed-off-by Ladislav Michl <[email protected]>--- drivers/mtd/core.c | 28 ++++++++++++++++++++++------ include/linux/kernel.h | 5 +++++ 2 files changed, 27 insertions(+), 6 deletions(-)Applied, thanks
Hi Sascha,
I was searching for paper bag, but was unable to find anything thick enouh to cover behind :-/ This version is buggy and I noticed right now when testing on another board. Corrected version follows, which is also 192 bytes shorter for my ARM target. It seems next branch at https://git.pengutronix.de/ is not yet updated, so perhaps my fault won't affect anyone.
--- 8< ---
From: Ladislav Michl <[email protected]>
Subject: [PATCH v2] mtd: core: Fix erase area alignment for non power of 2 erasesize
Devices as AT45DB161 DataFlash uses non power of two page size (528) while present alignment algorithm relies on erasesize being power of 2.
Fix that by introducing helper functions rounding to any multiply. Note that logic is sligthly changed to be consistent as ending address is moved forward to include also last byte meant to be erased while previous implementation moved it backward.
--- drivers/mtd/core.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-)
drivers/mtd/core.c +19 -6
@@ -141,15 +141,28 @@ static struct mtd_erase_region_info *mtd_find_erase_region(struct mtd_info *mtd,return NULL ; } +static loff_t __mtd_erase_round (loff_t x,uint32_t esize,int up) +{ +uint64_t dividend = x; +uint32_t mod =do_div (dividend, esize); +if (mod ==0 ) +return x; +if (up) + x += esize; +return x - mod; +} +#define mtd_erase_round_up (x, esize) __mtd_erase_round(x, esize, 1) +#define mtd_erase_round_down (x, esize) __mtd_erase_round(x, esize, 0) +static int mtd_erase_align (struct mtd_info *mtd,loff_t *count,loff_t *offset) {struct mtd_erase_region_info *e;loff_t ofs;if (mtd->numeraseregions ==0 ) { - ofs = *offset & ~(loff_t)(mtd->erasesize -1 ); - *count += (*offset - ofs); - *count =ALIGN (*count, mtd->erasesize); + ofs =mtd_erase_round_down (*offset, mtd->erasesize); + *count += *offset - ofs; + *count =mtd_erase_round_up (*count, mtd->erasesize); *offset = ofs;return 0 ; }
@@ -158,14 +171,14 @@ static int mtd_erase_align(struct mtd_info *mtd, loff_t *count, loff_t *offset)if (!e)return -EINVAL ; - ofs = *offset & ~(e->erasesize -1 ); - *count += (*offset - ofs); + ofs =mtd_erase_round_down (*offset, e->erasesize); + *count += *offset - ofs; e =mtd_find_erase_region (mtd, *offset + *count);if (!e)return -EINVAL ; - *count =ALIGN (*count, e->erasesize); + *count =mtd_erase_round_up (*count, e->erasesize); *offset = ofs;return 0 ;
Signature · 7 lines
2.20.1 _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
Quoted 18 lines · Ladislav Michl
Quoted 9 lines · Sascha Hauer
Quoted 8 lines · Ladislav Michl
Devices as AT45DB161 DataFlash uses non power of two page size (528) while present alignment algorithm relies on erasesize being power of 2.
Fix that by introducing helper functions rounding to any multiply. Note that logic is sligthly changed to be consistent as ending address is moved forward to include also last byte meant to be erased while previous implementation moved it backward.Quoted 7 lines
Quoted 5 lines
Signed-off-by Ladislav Michl <[email protected]>--- drivers/mtd/core.c | 28 ++++++++++++++++++++++------ include/linux/kernel.h | 5 +++++ 2 files changed, 27 insertions(+), 6 deletions(-)Applied, thanks
Quoted 8 lines
Hi Sascha,
I was searching for paper bag, but was unable to find anything thick enouh to cover behind :-/ This version is buggy and I noticed right now when testing on another board. Corrected version follows, which is also 192 bytes shorter for my ARM target. It seems next branch at https://git.pengutronix.de/ is not yet updated, so perhaps my fault won't affect anyone.
I did in the meantime, but updated it now again with your updated patch.
Sascha
Signature · 9 lines
Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox