The quilt patch titled Subject: mm/highmem: fix kernel-doc warnings in highmem*.h has been removed from the -mm tree. Its filename was mm-highmem-fix-kernel-doc-warnings-in-highmemh.patch This patch was dropped because it was merged into the mm-stable branch\nof git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "Fabio M. De Francesco" <fmdefrancesco@xxxxxxxxx> Subject: mm/highmem: fix kernel-doc warnings in highmem*.h Patch series "Extend and reorganize Highmem's documentation", v4. This series has the purpose to extend and reorganize Highmem's documentation. This is a work in progress because some information should still be moved from highmem.rst to highmem.h and highmem-internal.h. Specifically I'm talking about moving the "how to" information to the relevant headers, as it as been suggested by Ira Weiny (Intel). Also, this is a work in progress because some kdocs in highmem.h and highmem-internal.h should be improved. This patch (of 4): `scripts/kernel-doc -v -none include/linux/highmem*` reports the following warnings: include/linux/highmem.h:160: warning: expecting prototype for kunmap_atomic(). Prototype was for nr_free_highpages() instead include/linux/highmem.h:204: warning: No description found for return value of 'alloc_zeroed_user_highpage_movable' include/linux/highmem-internal.h:256: warning: Function parameter or member '__addr' not described in 'kunmap_atomic' include/linux/highmem-internal.h:256: warning: Excess function parameter 'addr' description in 'kunmap_atomic' Fix these warnings by (1) moving the kernel-doc comments from highmem.h to highmem-internal.h (which is the file were the kunmap_atomic() macro is actually defined), (2) extending and merging it with the comment which was already in highmem-internal.h, and (3) using correct parameter names (4) correcting a few technical inaccuracies in comments, and (5) adding a deprecation notice in kunmap_atomic() for consistency with kmap_atomic(). Link: https://lkml.kernel.org/r/20220428212455.892-1-fmdefrancesco@xxxxxxxxx Link: https://lkml.kernel.org/r/20220428212455.892-2-fmdefrancesco@xxxxxxxxx Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Cc: Peter Collingbourne <pcc@xxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/highmem-internal.h | 18 +++++++++++++++--- include/linux/highmem.h | 22 ++++++++-------------- 2 files changed, 23 insertions(+), 17 deletions(-) --- a/include/linux/highmem.h~mm-highmem-fix-kernel-doc-warnings-in-highmemh +++ a/include/linux/highmem.h @@ -37,7 +37,7 @@ static inline void *kmap(struct page *pa /** * kunmap - Unmap the virtual address mapped by kmap() - * @addr: Virtual address to be unmapped + * @page: Pointer to the page which was mapped by kmap() * * Counterpart to kmap(). A NOOP for CONFIG_HIGHMEM=n and for mappings of * pages in the low memory area. @@ -138,24 +138,16 @@ static inline void *kmap_local_folio(str * * Returns: The virtual address of the mapping * - * Effectively a wrapper around kmap_local_page() which disables pagefaults - * and preemption. + * In fact a wrapper around kmap_local_page() which also disables pagefaults + * and, depending on PREEMPT_RT configuration, also CPU migration and + * preemption. Therefore users should not count on the latter two side effects. + * + * Mappings should always be released by kunmap_atomic(). * * Do not use in new code. Use kmap_local_page() instead. */ static inline void *kmap_atomic(struct page *page); -/** - * kunmap_atomic - Unmap the virtual address mapped by kmap_atomic() - * @addr: Virtual address to be unmapped - * - * Counterpart to kmap_atomic(). - * - * Effectively a wrapper around kunmap_local() which additionally undoes - * the side effects of kmap_atomic(), i.e. reenabling pagefaults and - * preemption. - */ - /* Highmem related interfaces for management code */ static inline unsigned int nr_free_highpages(void); static inline unsigned long totalhigh_pages(void); @@ -191,6 +183,8 @@ static inline void clear_user_highpage(s * @vma: The VMA the page is to be allocated for * @vaddr: The virtual address the page will be inserted into * + * Returns: The allocated and zeroed HIGHMEM page + * * This function will allocate a page for a VMA that the caller knows will * be able to migrate in the future using move_pages() or reclaimed * --- a/include/linux/highmem-internal.h~mm-highmem-fix-kernel-doc-warnings-in-highmemh +++ a/include/linux/highmem-internal.h @@ -236,9 +236,21 @@ static inline unsigned long totalhigh_pa #endif /* CONFIG_HIGHMEM */ -/* - * Prevent people trying to call kunmap_atomic() as if it were kunmap() - * kunmap_atomic() should get the return value of kmap_atomic, not the page. +/** + * kunmap_atomic - Unmap the virtual address mapped by kmap_atomic() - deprecated! + * @__addr: Virtual address to be unmapped + * + * Unmaps an address previously mapped by kmap_atomic() and re-enables + * pagefaults. Depending on PREEMP_RT configuration, re-enables also + * migration and preemption. Users should not count on these side effects. + * + * Mappings should be unmapped in the reverse order that they were mapped. + * See kmap_local_page() for details on nesting. + * + * @__addr can be any address within the mapped page, so there is no need + * to subtract any offset that has been added. In contrast to kunmap(), + * this function takes the address returned from kmap_atomic(), not the + * page passed to it. The compiler will warn you if you pass the page. */ #define kunmap_atomic(__addr) \ do { \ _ Patches currently in -mm which might be from fmdefrancesco@xxxxxxxxx are