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authorMark Rutland <mark.rutland@arm.com>2016-01-25 11:45:00 +0000
committerCatalin Marinas <catalin.marinas@arm.com>2016-02-16 15:10:45 +0000
commit609116d202a8c5fd3fe393eb85373cbee906df68 (patch)
tree8e52f5fcb06cbbbe17bfa620c873666d18ac6ea3
parent86ccce896cb0aa800a7a6dcd29b41ffc4eeb1a75 (diff)
downloadop-kernel-dev-609116d202a8c5fd3fe393eb85373cbee906df68.zip
op-kernel-dev-609116d202a8c5fd3fe393eb85373cbee906df68.tar.gz
arm64: add function to install the idmap
In some cases (e.g. when making invasive changes to the kernel page tables) we will need to execute code from the idmap. Add a new helper which may be used to install the idmap, complementing the existing cpu_uninstall_idmap. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
-rw-r--r--arch/arm64/include/asm/mmu_context.h16
1 files changed, 14 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h
index b1b2514..944f273 100644
--- a/arch/arm64/include/asm/mmu_context.h
+++ b/arch/arm64/include/asm/mmu_context.h
@@ -74,7 +74,7 @@ static inline bool __cpu_uses_extended_idmap(void)
/*
* Set TCR.T0SZ to its default value (based on VA_BITS)
*/
-static inline void cpu_set_default_tcr_t0sz(void)
+static inline void __cpu_set_tcr_t0sz(unsigned long t0sz)
{
unsigned long tcr;
@@ -87,9 +87,12 @@ static inline void cpu_set_default_tcr_t0sz(void)
" msr tcr_el1, %0 ;"
" isb"
: "=&r" (tcr)
- : "r"(TCR_T0SZ(VA_BITS)), "I"(TCR_T0SZ_OFFSET), "I"(TCR_TxSZ_WIDTH));
+ : "r"(t0sz), "I"(TCR_T0SZ_OFFSET), "I"(TCR_TxSZ_WIDTH));
}
+#define cpu_set_default_tcr_t0sz() __cpu_set_tcr_t0sz(TCR_T0SZ(VA_BITS))
+#define cpu_set_idmap_tcr_t0sz() __cpu_set_tcr_t0sz(idmap_t0sz)
+
/*
* Remove the idmap from TTBR0_EL1 and install the pgd of the active mm.
*
@@ -114,6 +117,15 @@ static inline void cpu_uninstall_idmap(void)
cpu_switch_mm(mm->pgd, mm);
}
+static inline void cpu_install_idmap(void)
+{
+ cpu_set_reserved_ttbr0();
+ local_flush_tlb_all();
+ cpu_set_idmap_tcr_t0sz();
+
+ cpu_switch_mm(idmap_pg_dir, &init_mm);
+}
+
/*
* It would be nice to return ASIDs back to the allocator, but unfortunately
* that introduces a race with a generation rollover where we could erroneously
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