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authorJames Morse <james.morse@arm.com>2018-01-08 15:38:18 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2018-01-14 18:49:50 +0000
commit79e9aa59dc29a995921fb01e64cd36b73cf5abe0 (patch)
tree503e94412b80a2ef435ab418f5d68c1a55fcf53c /arch/arm64/include/asm/mmu.h
parent83f8ee3a73f551aebb5b0bb029feaf6936615730 (diff)
downloadop-kernel-dev-79e9aa59dc29a995921fb01e64cd36b73cf5abe0.zip
op-kernel-dev-79e9aa59dc29a995921fb01e64cd36b73cf5abe0.tar.gz
arm64: sdei: Add trampoline code for remapping the kernel
When CONFIG_UNMAP_KERNEL_AT_EL0 is set the SDEI entry point and the rest of the kernel may be unmapped when we take an event. If this may be the case, use an entry trampoline that can switch to the kernel page tables. We can't use the provided PSTATE to determine whether to switch page tables as we may have interrupted the kernel's entry trampoline, (or a normal-priority event that interrupted the kernel's entry trampoline). Instead test for a user ASID in ttbr1_el1. Save a value in regs->addr_limit to indicate whether we need to restore the original ASID when returning from this event. This value is only used by do_page_fault(), which we don't call with the SDEI regs. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/mmu.h')
-rw-r--r--arch/arm64/include/asm/mmu.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index 6dd83d7..a050d4f 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -17,7 +17,8 @@
#define __ASM_MMU_H
#define MMCF_AARCH32 0x1 /* mm context flag for AArch32 executables */
-#define USER_ASID_FLAG (UL(1) << 48)
+#define USER_ASID_BIT 48
+#define USER_ASID_FLAG (UL(1) << USER_ASID_BIT)
#define TTBR_ASID_MASK (UL(0xffff) << 48)
#ifndef __ASSEMBLY__
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