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Message-Id: <20171031153832.17746-4-james.morse@arm.com>
Date: Tue, 31 Oct 2017 15:38:29 +0000
From: James Morse <james.morse@....com>
To: linux-acpi@...r.kernel.org
Cc: linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
x86@...nel.org, Catalin Marinas <catalin.marinas@....com>,
Will Deacon <will.deacon@....com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H . Peter Anvin" <hpa@...or.com>, Borislav Petkov <bp@...e.de>,
"Rafael J . Wysocki" <rjw@...ysocki.net>,
Len Brown <lenb@...nel.org>, Tony Luck <tony.luck@...el.com>,
Tyler Baicar <tbaicar@...eaurora.org>,
Dongjiu Geng <gengdongjiu@...wei.com>,
Xie XiuQi <xiexiuqi@...wei.com>, torvalds@...ux-foundation.org,
James Morse <james.morse@....com>
Subject: [RFC/RFT PATCH 3/6] 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.
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@...el.com>
Suggested-by: Linus Torvalds <torvalds@...ux-foundation.org>
Signed-off-by: James Morse <james.morse@....com>
CC: Tyler Baicar <tbaicar@...eaurora.org>
CC: Dongjiu Geng <gengdongjiu@...wei.com>
CC: Xie XiuQi <xiexiuqi@...wei.com>
---
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 <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);
@@ -159,52 +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
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