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bh=0XIt0OG9v8n7AQWOk83zwx5cp0WK011IAZjG+scyfH4=; b=Spd0rKrVk5mEYc0dyTJ4iz+KcEIAt2OhrseiQcrt1t+X4bg1UccUo17ILUwR0E0cLm7whX sVUPsbNN+EiPEQ+AUFccwTs1C66JI38RWhB/b/Zl/VJwZpX/UjkoicHVZ3rakjR2gAUZjZ U1nTxsSsGfg9fJ4bBHcyGDw20lGzWiYqrRVXq00gGU9BNEXhi2a3Kzf4T17xi/gY3/8psy mjs51YEttlDICb5SbZ4kolv+JfcoDR4fMb+oUdLtW60zseOhaXFmIuJOyySm0ygg5e8SSJ 3bfHRXyurkul3vA0395FiZlvN+QvgPrb+JOi+uTghsinWNVdnTtpsF6dpaM7ag== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1604010732; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=0XIt0OG9v8n7AQWOk83zwx5cp0WK011IAZjG+scyfH4=; b=ZieSIkPqQ9T6Zn/Y+kRu7RVGaPV5thY3g3ejT/d6bLIns9xrZbjcZ7j4HxTIAoRF4tEwVz xc/ieNRL3cMbBFBA== Date: Thu, 29 Oct 2020 23:18:09 +0100 From: Thomas Gleixner To: LKML Subject: [patch V2 03/18] highmem: Provide generic variant of kmap_atomic* References: <20201029221806.189523375@linutronix.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201029_183213_473328_0627B8D1 X-CRM114-Status: GOOD ( 21.80 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Juri Lelli , linux-xtensa@linux-xtensa.org, Peter Zijlstra , Benjamin Herrenschmidt , Sebastian Andrzej Siewior , Ben Segall , linux-mm@kvack.org, Guo Ren , sparclinux@vger.kernel.org, Vincent Chen , Ingo Molnar , linux-arch@vger.kernel.org, Vincent Guittot , Herbert Xu , Michael Ellerman , x86@kernel.org, Russell King , linux-csky@vger.kernel.org, Christoph Hellwig , David Airlie , Mel Gorman , linux-snps-arc@lists.infradead.org, Ard Biesheuvel , Paul McKenney , linuxppc-dev@lists.ozlabs.org, Steven Rostedt , Linus Torvalds , Greentime Hu , Dietmar Eggemann , linux-arm-kernel@lists.infradead.org, Chris Zankel , Michal Simek , Thomas Bogendoerfer , Nick Hu , Max Filippov , Vineet Gupta , linux-mips@vger.kernel.org, Arnd Bergmann , Daniel Vetter , Paul Mackerras , Andrew Morton , Daniel Bristot de Oliveira , "David S. Miller" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org The kmap_atomic* interfaces in all architectures are pretty much the same except for post map operations (flush) and pre- and post unmap operations. Provide a generic variant for that. Signed-off-by: Thomas Gleixner Cc: Andrew Morton Cc: linux-mm@kvack.org --- V2: Address review comments from Christoph (style and EXPORT variant) --- include/linux/highmem.h | 79 ++++++++++++++++++++++++++------ mm/Kconfig | 3 + mm/highmem.c | 118 +++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 183 insertions(+), 17 deletions(-) --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -31,9 +31,16 @@ static inline void invalidate_kernel_vma #include +/* + * Outside of CONFIG_HIGHMEM to support X86 32bit iomap_atomic() cruft. + */ +#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); +#endif + #ifdef CONFIG_HIGHMEM -extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot); -extern void kunmap_atomic_high(void *kvaddr); #include #ifndef ARCH_HAS_KMAP_FLUSH_TLB @@ -81,6 +88,11 @@ static inline void kunmap(struct page *p * be used in IRQ contexts, so in some (very limited) cases we need * it. */ + +#ifndef CONFIG_KMAP_LOCAL +void *kmap_atomic_high_prot(struct page *page, pgprot_t prot); +void kunmap_atomic_high(void *kvaddr); + static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) { preempt_disable(); @@ -89,7 +101,38 @@ static inline void *kmap_atomic_prot(str return page_address(page); return kmap_atomic_high_prot(page, prot); } -#define kmap_atomic(page) kmap_atomic_prot(page, kmap_prot) + +static inline void __kunmap_atomic(void *vaddr) +{ + kunmap_atomic_high(vaddr); +} +#else /* !CONFIG_KMAP_LOCAL */ + +static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) +{ + preempt_disable(); + pagefault_disable(); + return __kmap_local_page_prot(page, prot); +} + +static inline void *kmap_atomic_pfn(unsigned long pfn) +{ + preempt_disable(); + pagefault_disable(); + return __kmap_local_pfn_prot(pfn, kmap_prot); +} + +static inline void __kunmap_atomic(void *addr) +{ + kunmap_local_indexed(addr); +} + +#endif /* CONFIG_KMAP_LOCAL */ + +static inline void *kmap_atomic(struct page *page) +{ + return kmap_atomic_prot(page, kmap_prot); +} /* declarations for linux/mm/highmem.c */ unsigned int nr_free_highpages(void); @@ -157,21 +200,28 @@ static inline void *kmap_atomic(struct p pagefault_disable(); return page_address(page); } -#define kmap_atomic_prot(page, prot) kmap_atomic(page) -static inline void kunmap_atomic_high(void *addr) +static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot) +{ + return kmap_atomic(page); +} + +static inline void *kmap_atomic_pfn(unsigned long pfn) +{ + return kmap_atomic(pfn_to_page(pfn)); +} + +static inline void __kunmap_atomic(void *addr) { /* * Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic() - * handles re-enabling faults + preemption + * handles re-enabling faults and preemption */ #ifdef ARCH_HAS_FLUSH_ON_KUNMAP kunmap_flush_on_unmap(addr); #endif } -#define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn)) - #define kmap_flush_unused() do {} while(0) #endif /* CONFIG_HIGHMEM */ @@ -213,15 +263,14 @@ static inline void kmap_atomic_idx_pop(v * 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. */ -#define kunmap_atomic(addr) \ -do { \ - BUILD_BUG_ON(__same_type((addr), struct page *)); \ - kunmap_atomic_high(addr); \ - pagefault_enable(); \ - preempt_enable(); \ +#define kunmap_atomic(__addr) \ +do { \ + BUILD_BUG_ON(__same_type((__addr), struct page *)); \ + __kunmap_atomic(__addr); \ + pagefault_enable(); \ + preempt_enable(); \ } while (0) - /* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ #ifndef clear_user_highpage static inline void clear_user_highpage(struct page *page, unsigned long vaddr) --- a/mm/Kconfig +++ b/mm/Kconfig @@ -872,4 +872,7 @@ config ARCH_HAS_HUGEPD config MAPPING_DIRTY_HELPERS bool +config KMAP_LOCAL + bool + endmenu --- a/mm/highmem.c +++ b/mm/highmem.c @@ -30,6 +30,7 @@ #include #include #include +#include #if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) DEFINE_PER_CPU(int, __kmap_atomic_idx); @@ -365,9 +366,122 @@ void kunmap_high(struct page *page) if (need_wakeup) wake_up(pkmap_map_wait); } - EXPORT_SYMBOL(kunmap_high); -#endif /* CONFIG_HIGHMEM */ +#endif /* CONFIG_HIGHMEM */ + +#ifdef CONFIG_KMAP_LOCAL +#ifndef arch_kmap_local_post_map +# define arch_kmap_local_post_map(vaddr, pteval) do { } while (0) +#endif + +#ifndef arch_kmap_local_pre_unmap +# define arch_kmap_local_pre_unmap(vaddr) do { } while (0) +#endif + +#ifndef arch_kmap_local_post_unmap +# define arch_kmap_local_post_unmap(vaddr) do { } while (0) +#endif + +#ifndef arch_kmap_local_map_idx +#define arch_kmap_local_map_idx(type, pfn) kmap_local_calc_idx(type) +#endif + +#ifndef arch_kmap_local_unmap_idx +#define arch_kmap_local_unmap_idx(type, vaddr) kmap_local_calc_idx(type) +#endif + +#ifndef arch_kmap_local_high_get +static inline void *arch_kmap_local_high_get(struct page *page) +{ + return NULL; +} +#endif + +/* Unmap a local mapping which was obtained by kmap_high_get() */ +static inline void kmap_high_unmap_local(unsigned long vaddr) +{ +#ifdef ARCH_NEEDS_KMAP_HIGH_GET + if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) + kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); +#endif +} + +static inline int kmap_local_calc_idx(int type) +{ + return type + KM_TYPE_NR * smp_processor_id(); +} + +static pte_t *__kmap_pte; + +static pte_t *kmap_get_pte(void) +{ + if (!__kmap_pte) + __kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN)); + return __kmap_pte; +} + +void *__kmap_local_pfn_prot(unsigned long pfn, pgprot_t prot) +{ + pte_t pteval, *kmap_pte = kmap_get_pte(); + unsigned long vaddr; + int idx; + + preempt_disable(); + idx = arch_kmap_local_map_idx(kmap_atomic_idx_push(), pfn); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + BUG_ON(!pte_none(*(kmap_pte - idx))); + pteval = pfn_pte(pfn, prot); + set_pte_at(&init_mm, vaddr, kmap_pte - idx, pteval); + arch_kmap_local_post_map(vaddr, pteval); + preempt_enable(); + + return (void *)vaddr; +} +EXPORT_SYMBOL_GPL(__kmap_local_pfn_prot); + +void *__kmap_local_page_prot(struct page *page, pgprot_t prot) +{ + void *kmap; + + if (!PageHighMem(page)) + return page_address(page); + + /* Try kmap_high_get() if architecture has it enabled */ + kmap = arch_kmap_local_high_get(page); + if (kmap) + return kmap; + + return __kmap_local_pfn_prot(page_to_pfn(page), prot); +} +EXPORT_SYMBOL(__kmap_local_page_prot); + +void kunmap_local_indexed(void *vaddr) +{ + unsigned long addr = (unsigned long) vaddr & PAGE_MASK; + pte_t *kmap_pte = kmap_get_pte(); + int idx; + + if (addr < __fix_to_virt(FIX_KMAP_END) || + addr > __fix_to_virt(FIX_KMAP_BEGIN)) { + WARN_ON_ONCE(addr < PAGE_OFFSET); + + /* Handle mappings which were obtained by kmap_high_get() */ + kmap_high_unmap_local(addr); + return; + } + + preempt_disable(); + idx = arch_kmap_local_unmap_idx(kmap_atomic_idx(), addr); + WARN_ON_ONCE(addr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); + + arch_kmap_local_pre_unmap(addr); + pte_clear(&init_mm, addr, kmap_pte - idx); + arch_kmap_local_post_unmap(addr); + kmap_atomic_idx_pop(); + preempt_enable(); +} +EXPORT_SYMBOL(kunmap_local_indexed); +#endif #if defined(HASHED_PAGE_VIRTUAL)