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Commit a1efdff4 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

arm64: cpufeatures: Drop the ARM64_HYP_OFFSET_LOW feature flag 



Now that we can dynamically compute the kernek/hyp VA mask, there
is no need for a feature flag to trigger the alternative patching.
Let's drop the flag and everything that depends on it.

Acked-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 2b4d1606

arch/arm64/include/asm/cpucaps.h

+1 −1
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ 
#define ARM64_HAS_VIRT_HOST_EXTN		11

#define ARM64_WORKAROUND_CAVIUM_27456		12

#define ARM64_HAS_32BIT_EL0			13

#define ARM64_HYP_OFFSET_LOW			14

/* #define ARM64_UNALLOCATED_ENTRY			14 */

#define ARM64_MISMATCHED_CACHE_LINE_SIZE	15

#define ARM64_HAS_NO_FPSIMD			16

#define ARM64_WORKAROUND_REPEAT_TLBI		17

arch/arm64/kernel/cpufeature.c

+0 −19
Original line number Diff line number Diff line
@@ -831,19 +831,6 @@ static bool runs_at_el2(const struct arm64_cpu_capabilities *entry, int __unused 
	return is_kernel_in_hyp_mode();

}



static bool hyp_offset_low(const struct arm64_cpu_capabilities *entry,

			   int __unused)

{

	phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start);



	/*

	 * Activate the lower HYP offset only if:

	 * - the idmap doesn't clash with it,

	 * - the kernel is not running at EL2.

	 */

	return idmap_addr > GENMASK(VA_BITS - 2, 0) && !is_kernel_in_hyp_mode();

}



static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused)

{

	u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1);
@@ -1029,12 +1016,6 @@ static const struct arm64_cpu_capabilities arm64_features[] = { 
		.field_pos = ID_AA64PFR0_EL0_SHIFT,

		.min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT,

	},

	{

		.desc = "Reduced HYP mapping offset",

		.capability = ARM64_HYP_OFFSET_LOW,

		.def_scope = SCOPE_SYSTEM,

		.matches = hyp_offset_low,

	},

#ifdef CONFIG_UNMAP_KERNEL_AT_EL0

	{

		.desc = "Kernel page table isolation (KPTI)",