From 39ade048a32ea653b94dcfbf816b0b13a6be8a33 Mon Sep 17 00:00:00 2001 From: "Fabio M. De Francesco" Date: Wed, 6 Jul 2022 13:15:19 +0200 Subject: [PATCH] highmem: Make __kunmap_{local,atomic}() take const void pointer __kunmap_ {local,atomic}() currently take pointers to void. However, this is semantically incorrect, since these functions do not change the memory their arguments point to. Therefore, make this semantics explicit by modifying the __kunmap_{local,atomic}() prototypes to take pointers to const void. As a side effect, compilers may produce more efficient code. Acked-by: Andrew Morton Acked-by: Helge Deller # parisc Suggested-by: David Sterba Suggested-by: Ira Weiny Reviewed-by: Ira Weiny Signed-off-by: Fabio M. De Francesco Reviewed-by: David Sterba Signed-off-by: David Sterba --- arch/parisc/include/asm/cacheflush.h | 6 +++--- arch/parisc/kernel/cache.c | 2 +- include/linux/highmem-internal.h | 10 +++++----- mm/highmem.c | 2 +- 4 files changed, 10 insertions(+), 10 deletions(-) diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h index 8d03b3b26229..0bdee6724132 100644 --- a/arch/parisc/include/asm/cacheflush.h +++ b/arch/parisc/include/asm/cacheflush.h @@ -22,7 +22,7 @@ void flush_kernel_icache_range_asm(unsigned long, unsigned long); void flush_user_dcache_range_asm(unsigned long, unsigned long); void flush_kernel_dcache_range_asm(unsigned long, unsigned long); void purge_kernel_dcache_range_asm(unsigned long, unsigned long); -void flush_kernel_dcache_page_asm(void *); +void flush_kernel_dcache_page_asm(const void *addr); void flush_kernel_icache_page(void *); /* Cache flush operations */ @@ -31,7 +31,7 @@ void flush_cache_all_local(void); void flush_cache_all(void); void flush_cache_mm(struct mm_struct *mm); -void flush_kernel_dcache_page_addr(void *addr); +void flush_kernel_dcache_page_addr(const void *addr); #define flush_kernel_dcache_range(start,size) \ flush_kernel_dcache_range_asm((start), (start)+(size)); @@ -75,7 +75,7 @@ void flush_dcache_page_asm(unsigned long phys_addr, unsigned long vaddr); void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr); #define ARCH_HAS_FLUSH_ON_KUNMAP -static inline void kunmap_flush_on_unmap(void *addr) +static inline void kunmap_flush_on_unmap(const void *addr) { flush_kernel_dcache_page_addr(addr); } diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index a9bc578e4c52..993999a65e54 100644 --- a/arch/parisc/kernel/cache.c +++ b/arch/parisc/kernel/cache.c @@ -549,7 +549,7 @@ extern void purge_kernel_dcache_page_asm(unsigned long); extern void clear_user_page_asm(void *, unsigned long); extern void copy_user_page_asm(void *, void *, unsigned long); -void flush_kernel_dcache_page_addr(void *addr) +void flush_kernel_dcache_page_addr(const void *addr) { unsigned long flags; diff --git a/include/linux/highmem-internal.h b/include/linux/highmem-internal.h index cddb42ff0473..034b1106d022 100644 --- a/include/linux/highmem-internal.h +++ b/include/linux/highmem-internal.h @@ -8,7 +8,7 @@ #ifdef CONFIG_KMAP_LOCAL void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot); void *__kmap_local_page_prot(struct page *page, pgprot_t prot); -void kunmap_local_indexed(void *vaddr); +void kunmap_local_indexed(const void *vaddr); void kmap_local_fork(struct task_struct *tsk); void __kmap_local_sched_out(void); void __kmap_local_sched_in(void); @@ -89,7 +89,7 @@ static inline void *kmap_local_pfn(unsigned long pfn) return __kmap_local_pfn_prot(pfn, kmap_prot); } -static inline void __kunmap_local(void *vaddr) +static inline void __kunmap_local(const void *vaddr) { kunmap_local_indexed(vaddr); } @@ -121,7 +121,7 @@ static inline void *kmap_atomic_pfn(unsigned long pfn) return __kmap_local_pfn_prot(pfn, kmap_prot); } -static inline void __kunmap_atomic(void *addr) +static inline void __kunmap_atomic(const void *addr) { kunmap_local_indexed(addr); pagefault_enable(); @@ -197,7 +197,7 @@ static inline void *kmap_local_pfn(unsigned long pfn) return kmap_local_page(pfn_to_page(pfn)); } -static inline void __kunmap_local(void *addr) +static inline void __kunmap_local(const void *addr) { #ifdef ARCH_HAS_FLUSH_ON_KUNMAP kunmap_flush_on_unmap(addr); @@ -224,7 +224,7 @@ static inline void *kmap_atomic_pfn(unsigned long pfn) return kmap_atomic(pfn_to_page(pfn)); } -static inline void __kunmap_atomic(void *addr) +static inline void __kunmap_atomic(const void *addr) { #ifdef ARCH_HAS_FLUSH_ON_KUNMAP kunmap_flush_on_unmap(addr); diff --git a/mm/highmem.c b/mm/highmem.c index 1a692997fac4..e32083e4ce0d 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -561,7 +561,7 @@ void *__kmap_local_page_prot(struct page *page, pgprot_t prot) } EXPORT_SYMBOL(__kmap_local_page_prot); -void kunmap_local_indexed(void *vaddr) +void kunmap_local_indexed(const void *vaddr) { unsigned long addr = (unsigned long) vaddr & PAGE_MASK; pte_t *kmap_pte;