kernel/linux.git/drivers/misc/xilinx_sdfec.c, branch v6.1.174

misc/xilinx_sdfec: Replace kmap() with kmap_local_page()

2022-09-09T08:22:36+00:00

kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as the mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap’s pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and still valid. Since its use in xilinx_sdfec.c is safe, replace kmap()i / kunmap() with kmap_local_page() / kunmap_local(). Cc: "Venkataramanan, Anirudh" Suggested-by: Ira Weiny Signed-off-by: Fabio M. De Francesco Link: https://lore.kernel.org/r/20220901154408.23984-3-fmdefrancesco@gmail.com Signed-off-by: Greg Kroah-Hartman

misc/xilinx_sdfec: Call kunmap() on pages mapped with kmap()

2022-09-09T08:22:36+00:00

Pages in an array are mapped in a loop but, after the code is done with the virtual addresses, these pages are never unmapped. Therefore, call kunmap() to unmap pages[i]. Cc: "Venkataramanan, Anirudh" Cc: Ira Weiny Signed-off-by: Fabio M. De Francesco Link: https://lore.kernel.org/r/20220901154408.23984-2-fmdefrancesco@gmail.com Signed-off-by: Greg Kroah-Hartman

misc: xilinx-sdfec: Drop unnecessary NULL check after container_of

2021-05-21T20:14:48+00:00

container_of() only returns NULL if the passed pointer is NULL _and_ if the embedded element is the first element of the structure. Even if that is the case, testing against it is misleading and possibly dangerous because the position of the embedded element may change. In this case, the check is unnecessary since it is known that file->private_data is never NULL for an open file, and container_of() will therefore also never be NULL. Drop the check. Acked-by: Dragan Cvetic Signed-off-by: Guenter Roeck Link: https://lore.kernel.org/r/20210521200457.2112041-1-linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman

misc: xilinx-sdfec: remove check for ioctl cmd and argument.

2020-11-03T09:11:48+00:00

if (_IOC_TYPE(cmd) != PP_IOCTL) return -ENOTTY; Invalid ioctl command check normally performs by “default” case. if (_IOC_DIR(cmd) != _IOC_NONE) { argp = (void __user *)arg; if (!argp) return -EINVAL; } And for checking ioctl arguments, copy_from_user()/copy_to_user() checks are enough. Reviewed-by: Arnd Bergmann Signed-off-by: Harshal Chaudhari Link: https://lore.kernel.org/r/20201101170949.18616-1-harshalchau04@gmail.com Signed-off-by: Greg Kroah-Hartman

misc: xilinx_sdfec: add compat_ptr_ioctl()

2020-10-29T07:37:36+00:00

Driver has a trivial helper function to convert the pointer argument and then call the native ioctl handler. But now we have a generic implementation for that, so we can use it. Signed-off-by: Harshal Chaudhari Link: https://lore.kernel.org/r/20201026155801.16053-1-harshalchau04@gmail.com Signed-off-by: Greg Kroah-Hartman

misc: xilinx-sdfec: convert get_user_pages() --> pin_user_pages()

2020-05-27T09:09:26+00:00

This code was using get_user_pages*(), in approximately a "Case 1" scenario (Direct IO), using the categorization from [1]. That means that it's time to convert the get_user_pages*() + put_page() calls to pin_user_pages*() + unpin_user_pages() calls. There is some helpful background in [2]: basically, this is a small part of fixing a long-standing disconnect between pinning pages, and file systems' use of those pages. [1] Documentation/core-api/pin_user_pages.rst [2] "Explicit pinning of user-space pages": https://lwn.net/Articles/807108/ Cc: Derek Kiernan Cc: Dragan Cvetic Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Michal Simek Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: John Hubbard Link: https://lore.kernel.org/r/20200527012628.1100649-4-jhubbard@nvidia.com Signed-off-by: Greg Kroah-Hartman

misc: xilinx-sdfec: cleanup return value in xsdfec_table_write()

2020-05-27T09:09:26+00:00

Return 0 for success, rather than the value of an incrementing "reg" index. The reg value was never actually used, so this simplifies the caller slightly. Cc: Derek Kiernan Cc: Dragan Cvetic Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Michal Simek Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: John Hubbard Link: https://lore.kernel.org/r/20200527012628.1100649-3-jhubbard@nvidia.com Signed-off-by: Greg Kroah-Hartman

misc: xilinx-sdfec: improve get_user_pages_fast() error handling

2020-05-27T09:09:26+00:00

This fixes the case of get_user_pages_fast() returning a -errno. The result needs to be stored in a signed integer. And for safe signed/unsigned comparisons, it's best to keep everything signed. And get_user_pages_fast() also expects a signed value for number of pages to pin. Therefore, change most relevant variables, from u32 to int. Leave "n" unsigned, for convenience in checking for overflow. And provide a WARN_ON_ONCE() and early return, if overflow occurs. Also, as long as we're tidying up: rename the page array from page, to pages, in order to match the conventions used in most other call sites. Fixes: 20ec628e8007e ("misc: xilinx_sdfec: Add ability to configure LDPC") Cc: Derek Kiernan Cc: Dragan Cvetic Cc: Arnd Bergmann Cc: Greg Kroah-Hartman Cc: Michal Simek Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: John Hubbard Link: https://lore.kernel.org/r/20200527012628.1100649-2-jhubbard@nvidia.com Signed-off-by: Greg Kroah-Hartman

misc: xilinx-sdfec: convert to module_platform_driver()

2020-05-15T14:20:01+00:00

The driver init and exit function don't do anything besides registering and unregistering the platform driver, so the module_platform_driver() macro could just be used instead of having separate functions. Signed-off-by: Harshal Chaudhari Acked-by: Dragan Cvetic Link: https://lore.kernel.org/r/20200510164308.31358-1-harshalchau04@gmail.com Signed-off-by: Greg Kroah-Hartman

misc: xilinx_sdfec: Use memdup_user() as a cleanup

2020-04-23T14:32:51+00:00

Fix coccicheck warning which recommends to use memdup_user(). This patch fixes the following coccicheck warnings: drivers/misc/xilinx_sdfec.c:652:8-15: WARNING opportunity for memdup_user Reported-by: Hulk Robot Signed-off-by: Zou Wei Link: https://lore.kernel.org/r/1587524330-119776-1-git-send-email-zou_wei@huawei.com Signed-off-by: Greg Kroah-Hartman