Commit 4f89fa28 authored by James Morse's avatar James Morse Committed by Rafael J. Wysocki
Browse files

ACPI / APEI: Replace ioremap_page_range() with fixmap 



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: default avatarFengguang Wu <fengguang.wu@intel.com>
Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Reviewed-by: default avatarBorislav Petkov <bp@suse.de>
Tested-by: default avatarTyler Baicar <tbaicar@codeaurora.org>
Tested-by: default avatarToshi Kani <toshi.kani@hpe.com>
[ For the arm64 bits: ]
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
[ For the x86 bits: ]
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: All applicable <stable@vger.kernel.org>
parent c49870e8

arch/arm64/include/asm/fixmap.h

+7 −0
Original line number Diff line number Diff line
@@ -51,6 +51,13 @@ enum fixed_addresses { 


	FIX_EARLYCON_MEM_BASE,

	FIX_TEXT_POKE0,



#ifdef CONFIG_ACPI_APEI_GHES

	/* Used for GHES mapping from assorted contexts */

	FIX_APEI_GHES_IRQ,

	FIX_APEI_GHES_NMI,

#endif /* CONFIG_ACPI_APEI_GHES */



	__end_of_permanent_fixed_addresses,



	/*

arch/x86/include/asm/fixmap.h

+6 −0
Original line number Diff line number Diff line
@@ -104,6 +104,12 @@ enum fixed_addresses { 
	FIX_GDT_REMAP_BEGIN,

	FIX_GDT_REMAP_END = FIX_GDT_REMAP_BEGIN + NR_CPUS - 1,



#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,



	/*

drivers/acpi/apei/ghes.c

+14 −30
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ 
#include <acpi/actbl1.h>

#include <acpi/ghes.h>

#include <acpi/apei.h>

#include <asm/fixmap.h>

#include <asm/tlbflush.h>

#include <ras/ras_event.h>
@@ -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);
@@ -159,53 +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;

	phys_addr_t 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)
@@ -361,10 +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);

		}

	}

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