kernel/linux.git/drivers/mtd/devices/phram.c, branch linux-6.0.y

mtd: phram: Allow cached mappings

2022-05-16T16:37:48+00:00

Currently phram always uses ioremap(), but this is unnecessary when normal memory is used. If the reserved-memory node does not specify the no-map property, indicating it should be mapped as system RAM and ioremap() cannot be used on it, use a cached mapping using memremap(MEMREMAP_WB) instead. On one of my systems this improves read performance by ~70%. (Note that this driver has always used normal memcpy/memset functions on memory obtained from ioremap(), which sparse doesn't like. There is no memremap() variant which maps exactly to ioremap() on all architectures, so that behaviour of the driver is not changed to avoid affecting existing users, but the sparse warnings are suppressed in the moved code with __force.) Signed-off-by: Vincent Whitchurch Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220510151822.1809278-1-vincent.whitchurch@axis.com

mtd: phram: Allow probing via reserved-memory

2022-04-25T08:37:49+00:00

Allow phram to be probed from the devicetree. It expects to be in a reserved-memory node as documented by the bindings. This allows things like partitioning to be specified via the devicetree. Signed-off-by: Vincent Whitchurch Acked-by: Rob Herring Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220412135302.1682890-4-vincent.whitchurch@axis.com

mtd: phram: Prevent divide by zero bug in phram_setup()

2022-01-25T09:32:07+00:00

The problem is that "erasesize" is a uint64_t type so it might be non-zero but the lower 32 bits are zero so when it's truncated, "(uint32_t)erasesize", then that value is zero. This leads to a divide by zero bug. Avoid the bug by delaying the divide until after we have validated that "erasesize" is non-zero and within the uint32_t range. Fixes: dc2b3e5cbc80 ("mtd: phram: use div_u64_rem to stop overwrite len in phram_setup") Signed-off-by: Dan Carpenter Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20220121115505.GI1978@kadam

mtd: phram: Fix error return code in phram_setup()

2021-05-10T08:44:34+00:00

Return a negative error code from the error handling case instead of 0, as done elsewhere in this function. Reported-by: Hulk Robot Signed-off-by: Yu Kuai Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20210408133812.1209798-1-yukuai3@huawei.com

mtd: phram: use div_u64_rem to stop overwrite len in phram_setup

2021-01-27T12:45:51+00:00

We now support user to set erase page size, and use do_div between len and erase size to determine the reasonableness for the erase size. However, do_div is a macro and will overwrite the value of len. Which results a mtd device with unexcepted size. Fix it by use div_u64_rem. Fixes: ffad560394de ("mtd: phram: Allow the user to set the erase page size.") Signed-off-by: yangerkun Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20210125124936.651812-1-yangerkun@huawei.com

mtd: phram: Allow the user to set the erase page size.

2020-12-07T11:29:19+00:00

Permit the user to specify the erase page size as a parameter. This solves two problems: - phram can access images made by mkfs.jffs2. mkfs.jffs2 won't create images with erase sizes less than 8KiB; many architectures define PAGE_SIZE as 4KiB. - Allows more effective use of small capacity devices. JFFS2 needs somewhere between 2 and 5 empty pages for garbage collection; and for an NVRAM part with only 32KiB of space, a smaller erase page allows much better utilization in applications where garbage collection is important. Signed-off-by: Patrick O'Grady Reviewed-by: Joern Engel Link: https://lore.kernel.org/lkml/CAJ7m5OqYv_=JB9NhHsqBsa8YU0DFRoP7C+W10PY22wonAGJK=A@mail.gmail.com/ [Guohua Zhong: fix token array index out of bounds and update patch for kernel master branch] Signed-off-by: Guohua Zhong Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20201207095529.20896-1-zhongguohua1@huawei.com

mtd: devices: phram: File headers are not good candidates for kernel-doc

2020-11-20T11:37:29+00:00

Fixes the following W=1 kernel build warning(s): drivers/mtd/devices/phram.c:19: warning: Function parameter or member 'fmt' not described in 'pr_fmt' Cc: Miquel Raynal Cc: Richard Weinberger Cc: Vignesh Raghavendra Cc: "Jochen Schäuble" Cc: linux-mtd@lists.infradead.org Signed-off-by: Lee Jones Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20201109182206.3037326-3-lee.jones@linaro.org

mtd: Convert fallthrough comments into statements

2020-03-30T08:14:54+00:00

Use Joe Perches cvt_fallthrough.pl script to convert /* fallthrough */ comments (and its derivatives) into a fallthrough; statement. This automatically drops useless ones. Do it MTD-wide. Signed-off-by: Miquel Raynal Acked-by: Vignesh Raghavendra Acked-by: Tudor Ambarus Acked-by: Richard Weinberger Link: https://lore.kernel.org/linux-mtd/20200325212115.14170-1-miquel.raynal@bootlin.com

mtd: phram: fix a double free issue in error path

2020-03-24T22:01:36+00:00

The variable 'name' is released multiple times in the error path, which may cause double free issues. This problem is avoided by adding a goto label to release the memory uniformly. And this change also makes the code a bit more cleaner. Fixes: 4f678a58d335 ("mtd: fix memory leaks in phram_setup") Signed-off-by: Wen Yang Cc: Joern Engel Cc: Miquel Raynal Cc: Richard Weinberger Cc: Vignesh Raghavendra Cc: linux-mtd@lists.infradead.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20200318153156.25612-1-wenyang@linux.alibaba.com

mtd: phram: Module parameters add writable permissions

2019-09-15T21:50:38+00:00

The phram code implements managing multiple devices through a linked list. However, due to the module parameter permission of 0, the /sys/module/phram/parameters/phram interface is missing. The command line arguments in insmod can only create one device. Therefore, add writable permissions to the module parameters, create /sys/module/phram/parameters/phram interface, and create multi-device support. Signed-off-by: Xiaoming Ni Signed-off-by: Richard Weinberger