From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Morse Subject: [RFC/RFT PATCH 3/6] ACPI / APEI: Replace ioremap_page_range() with fixmap Date: Tue, 31 Oct 2017 15:38:29 +0000 Message-ID: <20171031153832.17746-4-james.morse@arm.com> References: <20171031153832.17746-1-james.morse@arm.com> Return-path: In-Reply-To: <20171031153832.17746-1-james.morse@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-acpi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, Catalin Marinas , Will Deacon , Thomas Gleixner , Ingo Molnar , "H . Peter Anvin" , Borislav Petkov , "Rafael J . Wysocki" , Len Brown , Tony Luck , Tyler Baicar , Dongjiu Geng , Xie XiuQi , torvalds@linux-foundation.org, James Morse List-Id: linux-acpi@vger.kernel.org Replace ghes_io{re,un}map_pfn_{nmi,irq}()s use of ioremap_page_range() with __set_fixmap() as ioremap_page_range() may sleep to allocate a new level of page-table, even if its passed an existing final-address to use in the mapping. clear_fixmap() does the TLB invalidation in __set_fixmap() for arm64 and __set_pte_vaddr() for x86. In each case its the same as the respective arch_apei_flush_tlb_one(). Reported-by: Fengguang Wu Suggested-by: Linus Torvalds Signed-off-by: James Morse CC: Tyler Baicar CC: Dongjiu Geng CC: Xie XiuQi --- CC'd people I've seen posting CPER log fragments, could you give this a test on your platforms? drivers/acpi/apei/ghes.c | 45 +++++++++++++++------------------------------ 1 file changed, 15 insertions(+), 30 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 3c3a37b8503b..f3269816b997 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -51,6 +51,7 @@ #include #include #include +#include #include #include @@ -112,7 +113,7 @@ static DEFINE_MUTEX(ghes_list_mutex); * Because the memory area used to transfer hardware error information * from BIOS to Linux can be determined only in NMI, IRQ or timer * handler, but general ioremap can not be used in atomic context, so - * a special version of atomic ioremap is implemented for that. + * the fixmap is used instead. */ /* @@ -126,8 +127,8 @@ static DEFINE_MUTEX(ghes_list_mutex); /* virtual memory area for atomic ioremap */ static struct vm_struct *ghes_ioremap_area; /* - * These 2 spinlock is used to prevent atomic ioremap virtual memory - * area from being mapped simultaneously. + * These 2 spinlocks are used to prevent the fixmap entries from being used + * simultaneously. */ static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi); static DEFINE_SPINLOCK(ghes_ioremap_lock_irq); @@ -159,52 +160,36 @@ static void ghes_ioremap_exit(void) static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn) { - unsigned long vaddr; phys_addr_t paddr; pgprot_t prot; - vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr); - paddr = pfn << PAGE_SHIFT; prot = arch_apei_get_mem_attribute(paddr); - ioremap_page_range(vaddr, vaddr + PAGE_SIZE, paddr, prot); + __set_fixmap(FIX_APEI_GHES_NMI, paddr, prot); - return (void __iomem *)vaddr; + return (void __iomem *) fix_to_virt(FIX_APEI_GHES_NMI); } static void __iomem *ghes_ioremap_pfn_irq(u64 pfn) { - unsigned long vaddr, paddr; + unsigned long paddr; pgprot_t prot; - vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr); - paddr = pfn << PAGE_SHIFT; prot = arch_apei_get_mem_attribute(paddr); + __set_fixmap(FIX_APEI_GHES_IRQ, paddr, prot); - ioremap_page_range(vaddr, vaddr + PAGE_SIZE, paddr, prot); - - return (void __iomem *)vaddr; + return (void __iomem *) fix_to_virt(FIX_APEI_GHES_IRQ); } -static void ghes_iounmap_nmi(void __iomem *vaddr_ptr) +static void ghes_iounmap_nmi(void) { - unsigned long vaddr = (unsigned long __force)vaddr_ptr; - void *base = ghes_ioremap_area->addr; - - BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base)); - unmap_kernel_range_noflush(vaddr, PAGE_SIZE); - arch_apei_flush_tlb_one(vaddr); + clear_fixmap(FIX_APEI_GHES_NMI); } -static void ghes_iounmap_irq(void __iomem *vaddr_ptr) +static void ghes_iounmap_irq(void) { - unsigned long vaddr = (unsigned long __force)vaddr_ptr; - void *base = ghes_ioremap_area->addr; - - BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base)); - unmap_kernel_range_noflush(vaddr, PAGE_SIZE); - arch_apei_flush_tlb_one(vaddr); + clear_fixmap(FIX_APEI_GHES_IRQ); } static int ghes_estatus_pool_init(void) @@ -360,10 +345,10 @@ static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len, paddr += trunk; buffer += trunk; if (in_nmi) { - ghes_iounmap_nmi(vaddr); + ghes_iounmap_nmi(); raw_spin_unlock(&ghes_ioremap_lock_nmi); } else { - ghes_iounmap_irq(vaddr); + ghes_iounmap_irq(); spin_unlock_irqrestore(&ghes_ioremap_lock_irq, flags); } } -- 2.15.0.rc2 From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.morse@arm.com (James Morse) Date: Tue, 31 Oct 2017 15:38:29 +0000 Subject: [RFC/RFT PATCH 3/6] ACPI / APEI: Replace ioremap_page_range() with fixmap In-Reply-To: <20171031153832.17746-1-james.morse@arm.com> References: <20171031153832.17746-1-james.morse@arm.com> Message-ID: <20171031153832.17746-4-james.morse@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Replace ghes_io{re,un}map_pfn_{nmi,irq}()s use of ioremap_page_range() with __set_fixmap() as ioremap_page_range() may sleep to allocate a new level of page-table, even if its passed an existing final-address to use in the mapping. clear_fixmap() does the TLB invalidation in __set_fixmap() for arm64 and __set_pte_vaddr() for x86. In each case its the same as the respective arch_apei_flush_tlb_one(). Reported-by: Fengguang Wu Suggested-by: Linus Torvalds Signed-off-by: James Morse CC: Tyler Baicar CC: Dongjiu Geng CC: Xie XiuQi --- CC'd people I've seen posting CPER log fragments, could you give this a test on your platforms? drivers/acpi/apei/ghes.c | 45 +++++++++++++++------------------------------ 1 file changed, 15 insertions(+), 30 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 3c3a37b8503b..f3269816b997 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -51,6 +51,7 @@ #include #include #include +#include #include #include @@ -112,7 +113,7 @@ static DEFINE_MUTEX(ghes_list_mutex); * Because the memory area used to transfer hardware error information * from BIOS to Linux can be determined only in NMI, IRQ or timer * handler, but general ioremap can not be used in atomic context, so - * a special version of atomic ioremap is implemented for that. + * the fixmap is used instead. */ /* @@ -126,8 +127,8 @@ static DEFINE_MUTEX(ghes_list_mutex); /* virtual memory area for atomic ioremap */ static struct vm_struct *ghes_ioremap_area; /* - * These 2 spinlock is used to prevent atomic ioremap virtual memory - * area from being mapped simultaneously. + * These 2 spinlocks are used to prevent the fixmap entries from being used + * simultaneously. */ static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi); static DEFINE_SPINLOCK(ghes_ioremap_lock_irq); @@ -159,52 +160,36 @@ static void ghes_ioremap_exit(void) static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn) { - unsigned long vaddr; phys_addr_t paddr; pgprot_t prot; - vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr); - paddr = pfn << PAGE_SHIFT; prot = arch_apei_get_mem_attribute(paddr); - ioremap_page_range(vaddr, vaddr + PAGE_SIZE, paddr, prot); + __set_fixmap(FIX_APEI_GHES_NMI, paddr, prot); - return (void __iomem *)vaddr; + return (void __iomem *) fix_to_virt(FIX_APEI_GHES_NMI); } static void __iomem *ghes_ioremap_pfn_irq(u64 pfn) { - unsigned long vaddr, paddr; + unsigned long paddr; pgprot_t prot; - vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr); - paddr = pfn << PAGE_SHIFT; prot = arch_apei_get_mem_attribute(paddr); + __set_fixmap(FIX_APEI_GHES_IRQ, paddr, prot); - ioremap_page_range(vaddr, vaddr + PAGE_SIZE, paddr, prot); - - return (void __iomem *)vaddr; + return (void __iomem *) fix_to_virt(FIX_APEI_GHES_IRQ); } -static void ghes_iounmap_nmi(void __iomem *vaddr_ptr) +static void ghes_iounmap_nmi(void) { - unsigned long vaddr = (unsigned long __force)vaddr_ptr; - void *base = ghes_ioremap_area->addr; - - BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base)); - unmap_kernel_range_noflush(vaddr, PAGE_SIZE); - arch_apei_flush_tlb_one(vaddr); + clear_fixmap(FIX_APEI_GHES_NMI); } -static void ghes_iounmap_irq(void __iomem *vaddr_ptr) +static void ghes_iounmap_irq(void) { - unsigned long vaddr = (unsigned long __force)vaddr_ptr; - void *base = ghes_ioremap_area->addr; - - BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base)); - unmap_kernel_range_noflush(vaddr, PAGE_SIZE); - arch_apei_flush_tlb_one(vaddr); + clear_fixmap(FIX_APEI_GHES_IRQ); } static int ghes_estatus_pool_init(void) @@ -360,10 +345,10 @@ static void ghes_copy_tofrom_phys(void *buffer, u64 paddr, u32 len, paddr += trunk; buffer += trunk; if (in_nmi) { - ghes_iounmap_nmi(vaddr); + ghes_iounmap_nmi(); raw_spin_unlock(&ghes_ioremap_lock_nmi); } else { - ghes_iounmap_irq(vaddr); + ghes_iounmap_irq(); spin_unlock_irqrestore(&ghes_ioremap_lock_irq, flags); } } -- 2.15.0.rc2