Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753329AbbEFRxY (ORCPT ); Wed, 6 May 2015 13:53:24 -0400 Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:37171 "EHLO e06smtp11.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752729AbbEFRux (ORCPT ); Wed, 6 May 2015 13:50:53 -0400 From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: dahi@linux.vnet.ibm.com, mingo@redhat.com, peterz@infradead.org, yang.shi@windriver.com, bigeasy@linutronix.de, benh@kernel.crashing.org, paulus@samba.org, akpm@linux-foundation.org, heiko.carstens@de.ibm.com, schwidefsky@de.ibm.com, borntraeger@de.ibm.com, mst@redhat.com, tglx@linutronix.de, David.Laight@ACULAB.COM, hughd@google.com, hocko@suse.cz, ralf@linux-mips.org, herbert@gondor.apana.org.au, linux@arm.linux.org.uk, airlied@linux.ie, daniel.vetter@intel.com, linux-mm@kvack.org, linux-arch@vger.kernel.org Subject: [PATCH RFC 04/15] mm: explicitly disable/enable preemption in kmap_atomic_* Date: Wed, 6 May 2015 19:50:28 +0200 Message-Id: <1430934639-2131-5-git-send-email-dahi@linux.vnet.ibm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1430934639-2131-1-git-send-email-dahi@linux.vnet.ibm.com> References: <1430934639-2131-1-git-send-email-dahi@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15050617-0041-0000-0000-0000044EECFC Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11188 Lines: 400 The existing code relies on pagefault_disable() implicitly disabling preemption, so that no schedule will happen between kmap_atomic() and kunmap_atomic(). Let's make this explicit, to prepare for pagefault_disable() not touching preemption anymore. Signed-off-by: David Hildenbrand --- arch/arm/mm/highmem.c | 3 +++ arch/frv/mm/highmem.c | 2 ++ arch/metag/mm/highmem.c | 4 +++- arch/microblaze/mm/highmem.c | 4 +++- arch/mips/mm/highmem.c | 5 ++++- arch/mn10300/include/asm/highmem.h | 3 +++ arch/parisc/include/asm/cacheflush.h | 2 ++ arch/powerpc/mm/highmem.c | 4 +++- arch/sparc/mm/highmem.c | 4 +++- arch/tile/mm/highmem.c | 3 ++- arch/x86/mm/highmem_32.c | 3 ++- arch/x86/mm/iomap_32.c | 2 ++ arch/xtensa/mm/highmem.c | 2 ++ include/linux/highmem.h | 2 ++ include/linux/io-mapping.h | 2 ++ 15 files changed, 38 insertions(+), 7 deletions(-) diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c index b98895d..ee8dfa7 100644 --- a/arch/arm/mm/highmem.c +++ b/arch/arm/mm/highmem.c @@ -59,6 +59,7 @@ void *kmap_atomic(struct page *page) void *kmap; int type; + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -121,6 +122,7 @@ void __kunmap_atomic(void *kvaddr) kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); } pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); @@ -130,6 +132,7 @@ void *kmap_atomic_pfn(unsigned long pfn) int idx, type; struct page *page = pfn_to_page(pfn); + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); diff --git a/arch/frv/mm/highmem.c b/arch/frv/mm/highmem.c index bed9a9b..785344b 100644 --- a/arch/frv/mm/highmem.c +++ b/arch/frv/mm/highmem.c @@ -42,6 +42,7 @@ void *kmap_atomic(struct page *page) unsigned long paddr; int type; + preempt_disable(); pagefault_disable(); type = kmap_atomic_idx_push(); paddr = page_to_phys(page); @@ -85,5 +86,6 @@ void __kunmap_atomic(void *kvaddr) } kmap_atomic_idx_pop(); pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); diff --git a/arch/metag/mm/highmem.c b/arch/metag/mm/highmem.c index d71f621..807f1b1 100644 --- a/arch/metag/mm/highmem.c +++ b/arch/metag/mm/highmem.c @@ -43,7 +43,7 @@ void *kmap_atomic(struct page *page) unsigned long vaddr; int type; - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -82,6 +82,7 @@ void __kunmap_atomic(void *kvaddr) } pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); @@ -95,6 +96,7 @@ void *kmap_atomic_pfn(unsigned long pfn) unsigned long vaddr; int type; + preempt_disable(); pagefault_disable(); type = kmap_atomic_idx_push(); diff --git a/arch/microblaze/mm/highmem.c b/arch/microblaze/mm/highmem.c index 5a92576..2fcc5a5 100644 --- a/arch/microblaze/mm/highmem.c +++ b/arch/microblaze/mm/highmem.c @@ -37,7 +37,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot) unsigned long vaddr; int idx, type; - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -63,6 +63,7 @@ void __kunmap_atomic(void *kvaddr) if (vaddr < __fix_to_virt(FIX_KMAP_END)) { pagefault_enable(); + preempt_enable(); return; } @@ -84,5 +85,6 @@ void __kunmap_atomic(void *kvaddr) #endif kmap_atomic_idx_pop(); pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c index da815d2..11661cb 100644 --- a/arch/mips/mm/highmem.c +++ b/arch/mips/mm/highmem.c @@ -47,7 +47,7 @@ void *kmap_atomic(struct page *page) unsigned long vaddr; int idx, type; - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -72,6 +72,7 @@ void __kunmap_atomic(void *kvaddr) if (vaddr < FIXADDR_START) { // FIXME pagefault_enable(); + preempt_enable(); return; } @@ -92,6 +93,7 @@ void __kunmap_atomic(void *kvaddr) #endif kmap_atomic_idx_pop(); pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); @@ -104,6 +106,7 @@ void *kmap_atomic_pfn(unsigned long pfn) unsigned long vaddr; int idx, type; + preempt_disable(); pagefault_disable(); type = kmap_atomic_idx_push(); diff --git a/arch/mn10300/include/asm/highmem.h b/arch/mn10300/include/asm/highmem.h index 2fbbe4d..1ddea5a 100644 --- a/arch/mn10300/include/asm/highmem.h +++ b/arch/mn10300/include/asm/highmem.h @@ -75,6 +75,7 @@ static inline void *kmap_atomic(struct page *page) unsigned long vaddr; int idx, type; + preempt_disable(); pagefault_disable(); if (page < highmem_start_page) return page_address(page); @@ -98,6 +99,7 @@ static inline void __kunmap_atomic(unsigned long vaddr) if (vaddr < FIXADDR_START) { /* FIXME */ pagefault_enable(); + preempt_enable(); return; } @@ -122,6 +124,7 @@ static inline void __kunmap_atomic(unsigned long vaddr) kmap_atomic_idx_pop(); pagefault_enable(); + preempt_enable(); } #endif /* __KERNEL__ */ diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h index de65f66..ec2df4b 100644 --- a/arch/parisc/include/asm/cacheflush.h +++ b/arch/parisc/include/asm/cacheflush.h @@ -142,6 +142,7 @@ static inline void kunmap(struct page *page) static inline void *kmap_atomic(struct page *page) { + preempt_disable(); pagefault_disable(); return page_address(page); } @@ -150,6 +151,7 @@ static inline void __kunmap_atomic(void *addr) { flush_kernel_dcache_page_addr(addr); pagefault_enable(); + preempt_enable(); } #define kmap_atomic_prot(page, prot) kmap_atomic(page) diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c index e7450bd..e292c8a 100644 --- a/arch/powerpc/mm/highmem.c +++ b/arch/powerpc/mm/highmem.c @@ -34,7 +34,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot) unsigned long vaddr; int idx, type; - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -59,6 +59,7 @@ void __kunmap_atomic(void *kvaddr) if (vaddr < __fix_to_virt(FIX_KMAP_END)) { pagefault_enable(); + preempt_enable(); return; } @@ -82,5 +83,6 @@ void __kunmap_atomic(void *kvaddr) kmap_atomic_idx_pop(); pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c index 449f864..a454ec5 100644 --- a/arch/sparc/mm/highmem.c +++ b/arch/sparc/mm/highmem.c @@ -53,7 +53,7 @@ void *kmap_atomic(struct page *page) unsigned long vaddr; long idx, type; - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -91,6 +91,7 @@ void __kunmap_atomic(void *kvaddr) if (vaddr < FIXADDR_START) { // FIXME pagefault_enable(); + preempt_enable(); return; } @@ -126,5 +127,6 @@ void __kunmap_atomic(void *kvaddr) kmap_atomic_idx_pop(); pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); diff --git a/arch/tile/mm/highmem.c b/arch/tile/mm/highmem.c index 6aa2f26..fcd5450 100644 --- a/arch/tile/mm/highmem.c +++ b/arch/tile/mm/highmem.c @@ -201,7 +201,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot) int idx, type; pte_t *pte; - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + preempt_disable(); pagefault_disable(); /* Avoid icache flushes by disallowing atomic executable mappings. */ @@ -259,6 +259,7 @@ void __kunmap_atomic(void *kvaddr) } pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c index 4500142..eecb207a 100644 --- a/arch/x86/mm/highmem_32.c +++ b/arch/x86/mm/highmem_32.c @@ -35,7 +35,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot) unsigned long vaddr; int idx, type; - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) @@ -100,6 +100,7 @@ void __kunmap_atomic(void *kvaddr) #endif pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); diff --git a/arch/x86/mm/iomap_32.c b/arch/x86/mm/iomap_32.c index 9ca35fc..2b7ece0 100644 --- a/arch/x86/mm/iomap_32.c +++ b/arch/x86/mm/iomap_32.c @@ -59,6 +59,7 @@ void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) unsigned long vaddr; int idx, type; + preempt_disable(); pagefault_disable(); type = kmap_atomic_idx_push(); @@ -117,5 +118,6 @@ iounmap_atomic(void __iomem *kvaddr) } pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL_GPL(iounmap_atomic); diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c index 8cfb71e..184cead 100644 --- a/arch/xtensa/mm/highmem.c +++ b/arch/xtensa/mm/highmem.c @@ -42,6 +42,7 @@ void *kmap_atomic(struct page *page) enum fixed_addresses idx; unsigned long vaddr; + preempt_disable(); pagefault_disable(); if (!PageHighMem(page)) return page_address(page); @@ -79,6 +80,7 @@ void __kunmap_atomic(void *kvaddr) } pagefault_enable(); + preempt_enable(); } EXPORT_SYMBOL(__kunmap_atomic); diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 9286a46..6aefcd0 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -65,6 +65,7 @@ static inline void kunmap(struct page *page) static inline void *kmap_atomic(struct page *page) { + preempt_disable(); pagefault_disable(); return page_address(page); } @@ -73,6 +74,7 @@ static inline void *kmap_atomic(struct page *page) static inline void __kunmap_atomic(void *addr) { pagefault_enable(); + preempt_enable(); } #define kmap_atomic_pfn(pfn) kmap_atomic(pfn_to_page(pfn)) diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h index 657fab4..c27dde7 100644 --- a/include/linux/io-mapping.h +++ b/include/linux/io-mapping.h @@ -141,6 +141,7 @@ static inline void __iomem * io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset) { + preempt_disable(); pagefault_disable(); return ((char __force __iomem *) mapping) + offset; } @@ -149,6 +150,7 @@ static inline void io_mapping_unmap_atomic(void __iomem *vaddr) { pagefault_enable(); + preempt_enable(); } /* Non-atomic map/unmap */ -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/