3.16.54-rc1 review patch. If anyone has any objections, please let me know.
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From: James Morse james.morse@arm.com
commit 4f89fa286f6729312e227e7c2d764e8e7b9d340e upstream.
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.
The GHES driver can only be enabled for architectures that select HAVE_ACPI_APEI: Add fixmap entries to both x86 and arm64.
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 fengguang.wu@intel.com Suggested-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: James Morse james.morse@arm.com Reviewed-by: Borislav Petkov bp@suse.de Tested-by: Tyler Baicar tbaicar@codeaurora.org Tested-by: Toshi Kani toshi.kani@hpe.com [ For the arm64 bits: ] Acked-by: Will Deacon will.deacon@arm.com [ For the x86 bits: ] Acked-by: Ingo Molnar mingo@kernel.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com [bwh: Backported to 3.16: - Drop arm64 changes; ghes is x86-only here - Don't use page or prot variables in ghes_ioremap_fn_{nmi,irq}() - Adjust context] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- --- a/arch/x86/include/asm/fixmap.h +++ b/arch/x86/include/asm/fixmap.h @@ -103,6 +103,12 @@ enum fixed_addresses { #ifdef CONFIG_X86_INTEL_MID FIX_LNW_VRTC, #endif +#ifdef CONFIG_ACPI_APEI_GHES + /* Used for GHES mapping from assorted contexts */ + FIX_APEI_GHES_IRQ, + FIX_APEI_GHES_NMI, +#endif + __end_of_permanent_fixed_addresses,
/* --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -49,6 +49,7 @@ #include <linux/aer.h>
#include <acpi/ghes.h> +#include <asm/fixmap.h> #include <asm/mce.h> #include <asm/tlbflush.h> #include <asm/nmi.h> @@ -110,7 +111,7 @@ static DEFINE_RAW_SPINLOCK(ghes_nmi_lock * 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. */
/* @@ -124,8 +125,8 @@ static DEFINE_RAW_SPINLOCK(ghes_nmi_lock /* 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); @@ -165,44 +166,26 @@ static void ghes_ioremap_exit(void)
static void __iomem *ghes_ioremap_pfn_nmi(u64 pfn) { - unsigned long vaddr; + __set_fixmap(FIX_APEI_GHES_NMI, pfn << PAGE_SHIFT, PAGE_KERNEL);
- vaddr = (unsigned long)GHES_IOREMAP_NMI_PAGE(ghes_ioremap_area->addr); - ioremap_page_range(vaddr, vaddr + PAGE_SIZE, - pfn << PAGE_SHIFT, PAGE_KERNEL); - - 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; - - vaddr = (unsigned long)GHES_IOREMAP_IRQ_PAGE(ghes_ioremap_area->addr); - ioremap_page_range(vaddr, vaddr + PAGE_SIZE, - pfn << PAGE_SHIFT, PAGE_KERNEL); + __set_fixmap(FIX_APEI_GHES_IRQ, pfn << PAGE_SHIFT, PAGE_KERNEL);
- 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); - __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); - __flush_tlb_one(vaddr); + clear_fixmap(FIX_APEI_GHES_IRQ); }
static int ghes_estatus_pool_init(void) @@ -341,10 +324,10 @@ static void ghes_copy_tofrom_phys(void * 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); } }