diff options
Diffstat (limited to 'nixos/modules/kernel-patches/0045-mtd-spi-nor-write-support-for-minor-aligned-partitio.patch')
| -rw-r--r-- | nixos/modules/kernel-patches/0045-mtd-spi-nor-write-support-for-minor-aligned-partitio.patch | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/nixos/modules/kernel-patches/0045-mtd-spi-nor-write-support-for-minor-aligned-partitio.patch b/nixos/modules/kernel-patches/0045-mtd-spi-nor-write-support-for-minor-aligned-partitio.patch new file mode 100644 index 0000000..1374147 --- /dev/null +++ b/nixos/modules/kernel-patches/0045-mtd-spi-nor-write-support-for-minor-aligned-partitio.patch @@ -0,0 +1,238 @@ +From cb9e7995c29b8c25bd84b3f47797d67dbf6dfd0e Mon Sep 17 00:00:00 2001 +From: John Thomson <git@johnthomson.fastmail.com.au> +Date: Fri, 25 Dec 2020 18:50:08 +1000 +Subject: [PATCH 45/96] mtd: spi-nor: write support for minor aligned + partitions +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Do not prevent writing to mtd partitions where a partition boundary sits +on a minor erasesize boundary. +This addresses a FIXME that has been present since the start of the +linux git history: +/* Doesn't start on a boundary of major erase size */ +/* FIXME: Let it be writable if it is on a boundary of + * _minor_ erase size though */ + +Allow a uniform erase region spi-nor device to be configured +to use the non-uniform erase regions code path for an erase with: +CONFIG_MTD_SPI_NOR_USE_VARIABLE_ERASE=y + +On supporting hardware (SECT_4K: majority of current SPI-NOR device) +provide the facility for an erase to use the least number +of SPI-NOR operations, as well as access to 4K erase without +requiring CONFIG_MTD_SPI_NOR_USE_4K_SECTORS + +Introduce erasesize_minor to the mtd struct, +the smallest erasesize supported by the device + +On existing devices, this is useful where write support is wanted +for data on a 4K partition, such as some u-boot-env partitions, +or RouterBoot soft_config, while still netting the performance +benefits of using 64K sectors + +Performance: +time mtd erase firmware +OpenWrt 5.10 ramips MT7621 w25q128jv 0xfc0000 partition length + +Without this patch +MTD_SPI_NOR_USE_4K_SECTORS=y |n +real 2m 11.66s |0m 50.86s +user 0m 0.00s |0m 0.00s +sys 1m 56.20s |0m 50.80s + +With this patch +MTD_SPI_NOR_USE_VARIABLE_ERASE=n|y |4K_SECTORS=y +real 0m 51.68s |0m 50.85s |2m 12.89s +user 0m 0.00s |0m 0.00s |0m 0.01s +sys 0m 46.94s |0m 50.38s |2m 12.46s + +Signed-off-by: John Thomson <git@johnthomson.fastmail.com.au> +Signed-off-by: Thibaut VARÈNE <hacks+kernel@slashdirt.org> +--- + drivers/mtd/mtdcore.c | 10 ++++++++++ + drivers/mtd/mtdpart.c | 35 +++++++++++++++++++++++++---------- + drivers/mtd/spi-nor/Kconfig | 10 ++++++++++ + drivers/mtd/spi-nor/core.c | 11 +++++++++-- + include/linux/mtd/mtd.h | 2 ++ + 5 files changed, 56 insertions(+), 12 deletions(-) + +diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c +index 9eb0680db312..ccb80197d960 100644 +--- a/drivers/mtd/mtdcore.c ++++ b/drivers/mtd/mtdcore.c +@@ -168,6 +168,15 @@ static ssize_t mtd_erasesize_show(struct device *dev, + } + MTD_DEVICE_ATTR_RO(erasesize); + ++static ssize_t mtd_erasesize_minor_show(struct device *dev, ++ struct device_attribute *attr, char *buf) ++{ ++ struct mtd_info *mtd = dev_get_drvdata(dev); ++ ++ return sysfs_emit(buf, "%lu\n", (unsigned long)mtd->erasesize_minor); ++} ++MTD_DEVICE_ATTR_RO(erasesize_minor); ++ + static ssize_t mtd_writesize_show(struct device *dev, + struct device_attribute *attr, char *buf) + { +@@ -313,6 +322,7 @@ static struct attribute *mtd_attrs[] = { + &dev_attr_flags.attr, + &dev_attr_size.attr, + &dev_attr_erasesize.attr, ++ &dev_attr_erasesize_minor.attr, + &dev_attr_writesize.attr, + &dev_attr_subpagesize.attr, + &dev_attr_oobsize.attr, +diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c +index f1ed12aae1fe..0b7be183a1f6 100644 +--- a/drivers/mtd/mtdpart.c ++++ b/drivers/mtd/mtdpart.c +@@ -41,6 +41,7 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, + struct mtd_info *master = mtd_get_master(parent); + int wr_alignment = (parent->flags & MTD_NO_ERASE) ? + master->writesize : master->erasesize; ++ int wr_alignment_minor = 0; + u64 parent_size = mtd_is_partition(parent) ? + parent->part.size : parent->size; + struct mtd_info *child; +@@ -165,6 +166,7 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, + } else { + /* Single erase size */ + child->erasesize = master->erasesize; ++ child->erasesize_minor = master->erasesize_minor; + } + + /* +@@ -172,26 +174,39 @@ static struct mtd_info *allocate_partition(struct mtd_info *parent, + * exposes several regions with different erasesize. Adjust + * wr_alignment accordingly. + */ +- if (!(child->flags & MTD_NO_ERASE)) ++ if (!(child->flags & MTD_NO_ERASE)) { + wr_alignment = child->erasesize; ++ wr_alignment_minor = child->erasesize_minor; ++ } + + tmp = mtd_get_master_ofs(child, 0); + remainder = do_div(tmp, wr_alignment); + if ((child->flags & MTD_WRITEABLE) && remainder) { +- /* Doesn't start on a boundary of major erase size */ +- /* FIXME: Let it be writable if it is on a boundary of +- * _minor_ erase size though */ +- child->flags &= ~MTD_WRITEABLE; +- printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n", +- part->name); ++ if (wr_alignment_minor) { ++ /* rely on minor being a factor of major erasesize */ ++ tmp = remainder; ++ remainder = do_div(tmp, wr_alignment_minor); ++ } ++ if (remainder) { ++ child->flags &= ~MTD_WRITEABLE; ++ printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase/write block boundary -- force read-only\n", ++ part->name); ++ } + } + + tmp = mtd_get_master_ofs(child, 0) + child->part.size; + remainder = do_div(tmp, wr_alignment); + if ((child->flags & MTD_WRITEABLE) && remainder) { +- child->flags &= ~MTD_WRITEABLE; +- printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n", +- part->name); ++ if (wr_alignment_minor) { ++ tmp = remainder; ++ remainder = do_div(tmp, wr_alignment_minor); ++ } ++ ++ if (remainder) { ++ child->flags &= ~MTD_WRITEABLE; ++ printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase/write block -- force read-only\n", ++ part->name); ++ } + } + + child->size = child->part.size; +diff --git a/drivers/mtd/spi-nor/Kconfig b/drivers/mtd/spi-nor/Kconfig +index 24cd25de2b8b..09df9f1a8127 100644 +--- a/drivers/mtd/spi-nor/Kconfig ++++ b/drivers/mtd/spi-nor/Kconfig +@@ -10,6 +10,16 @@ menuconfig MTD_SPI_NOR + + if MTD_SPI_NOR + ++config MTD_SPI_NOR_USE_VARIABLE_ERASE ++ bool "Disable uniform_erase to allow use of all hardware supported erasesizes" ++ depends on !MTD_SPI_NOR_USE_4K_SECTORS ++ default n ++ help ++ Allow mixed use of all hardware supported erasesizes, ++ by forcing spi_nor to use the multiple eraseregions code path. ++ For example: A 68K erase will use one 64K erase, and one 4K erase ++ on supporting hardware. ++ + config MTD_SPI_NOR_USE_4K_SECTORS + bool "Use small 4096 B erase sectors" + default y +diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c +index e758ebfe1a9f..f237f050b43c 100644 +--- a/drivers/mtd/spi-nor/core.c ++++ b/drivers/mtd/spi-nor/core.c +@@ -1048,6 +1048,8 @@ static u8 spi_nor_convert_3to4_erase(u8 opcode) + + static bool spi_nor_has_uniform_erase(const struct spi_nor *nor) + { ++ if (IS_ENABLED(CONFIG_MTD_SPI_NOR_USE_VARIABLE_ERASE)) ++ return false; + return !!nor->params->erase_map.uniform_erase_type; + } + +@@ -2144,6 +2146,7 @@ static int spi_nor_select_erase(struct spi_nor *nor) + { + struct spi_nor_erase_map *map = &nor->params->erase_map; + const struct spi_nor_erase_type *erase = NULL; ++ const struct spi_nor_erase_type *erase_minor = NULL; + struct mtd_info *mtd = &nor->mtd; + u32 wanted_size = nor->info->sector_size; + int i; +@@ -2176,8 +2179,9 @@ static int spi_nor_select_erase(struct spi_nor *nor) + */ + for (i = SNOR_ERASE_TYPE_MAX - 1; i >= 0; i--) { + if (map->erase_type[i].size) { +- erase = &map->erase_type[i]; +- break; ++ if (!erase) ++ erase = &map->erase_type[i]; ++ erase_minor = &map->erase_type[i]; + } + } + +@@ -2185,6 +2189,9 @@ static int spi_nor_select_erase(struct spi_nor *nor) + return -EINVAL; + + mtd->erasesize = erase->size; ++ if (IS_ENABLED(CONFIG_MTD_SPI_NOR_USE_VARIABLE_ERASE) && ++ erase_minor && erase_minor->size < erase->size) ++ mtd->erasesize_minor = erase_minor->size; + return 0; + } + +diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h +index e2359a3569f0..cd7807a23123 100644 +--- a/include/linux/mtd/mtd.h ++++ b/include/linux/mtd/mtd.h +@@ -238,6 +238,8 @@ struct mtd_info { + * information below if they desire + */ + uint32_t erasesize; ++ /* "Minor" (smallest) erase size supported by the whole device */ ++ uint32_t erasesize_minor; + /* Minimal writable flash unit size. In case of NOR flash it is 1 (even + * though individual bits can be cleared), in case of NAND flash it is + * one NAND page (or half, or one-fourths of it), in case of ECC-ed NOR +-- +2.37.2 + |