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Commit 005e975a authored by Marc Zyngier's avatar Marc Zyngier
Browse files

arm64: KVM: Dynamically compute the HYP VA mask 



As we're moving towards a much more dynamic way to compute our
HYP VA, let's express the mask in a slightly different way.

Instead of comparing the idmap position to the "low" VA mask,
we directly compute the mask by taking into account the idmap's
(VA_BIT-1) bit.

No functionnal change.

Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 11d76407

arch/arm64/kvm/va_layout.c

+6 −11
Original line number Diff line number Diff line
@@ -21,24 +21,19 @@ 
#include <asm/insn.h>

#include <asm/kvm_mmu.h>



#define HYP_PAGE_OFFSET_HIGH_MASK	((UL(1) << VA_BITS) - 1)

#define HYP_PAGE_OFFSET_LOW_MASK	((UL(1) << (VA_BITS - 1)) - 1)



static u64 va_mask;



static void compute_layout(void)

{

	phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start);

	unsigned long mask = HYP_PAGE_OFFSET_HIGH_MASK;

	u64 hyp_va_msb;



	/*

	 * Activate the lower HYP offset only if the idmap doesn't

	 * clash with it,

	 */

	if (idmap_addr > HYP_PAGE_OFFSET_LOW_MASK)

		mask = HYP_PAGE_OFFSET_LOW_MASK;

	/* Where is my RAM region? */

	hyp_va_msb  = idmap_addr & BIT(VA_BITS - 1);

	hyp_va_msb ^= BIT(VA_BITS - 1);



	va_mask = mask;

	va_mask  = GENMASK_ULL(VA_BITS - 2, 0);

	va_mask |= hyp_va_msb;

}



static u32 compute_instruction(int n, u32 rd, u32 rn)