Commit 19b0e60a authored by Victor Kamensky's avatar Victor Kamensky Committed by Christoffer Dall
Browse files

ARM: KVM: handle 64bit values passed to mrcc or from mcrr instructions in BE case 



In some cases the mcrr and mrrc instructions in combination with the ldrd
and strd instructions need to deal with 64bit value in memory. The ldrd
and strd instructions already handle endianness within word (register)
boundaries but to get effect of the whole 64bit value represented correctly,
rr_lo_hi macro is introduced and is used to swap registers positions when
the mcrr and mrrc instructions are used. That has the effect of swapping
two words.

Signed-off-by: default avatarVictor Kamensky <victor.kamensky@linaro.org>
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 64054c25

arch/arm/include/asm/kvm_asm.h

+18 −0
Original line number Diff line number Diff line
@@ -61,6 +61,24 @@ 
#define ARM_EXCEPTION_FIQ	  6

#define ARM_EXCEPTION_HVC	  7



/*

 * The rr_lo_hi macro swaps a pair of registers depending on

 * current endianness. It is used in conjunction with ldrd and strd

 * instructions that load/store a 64-bit value from/to memory to/from

 * a pair of registers which are used with the mrrc and mcrr instructions.

 * If used with the ldrd/strd instructions, the a1 parameter is the first

 * source/destination register and the a2 parameter is the second

 * source/destination register. Note that the ldrd/strd instructions

 * already swap the bytes within the words correctly according to the

 * endianness setting, but the order of the registers need to be effectively

 * swapped when used with the mrrc/mcrr instructions.

 */

#ifdef CONFIG_CPU_ENDIAN_BE8

#define rr_lo_hi(a1, a2) a2, a1

#else

#define rr_lo_hi(a1, a2) a1, a2

#endif



#ifndef __ASSEMBLY__

struct kvm;

struct kvm_vcpu;

arch/arm/kvm/init.S

+2 −2
Original line number Diff line number Diff line
@@ -71,7 +71,7 @@ __do_hyp_init: 
	bne	phase2			@ Yes, second stage init



	@ Set the HTTBR to point to the hypervisor PGD pointer passed

	mcrr	p15, 4, r2, r3, c2

	mcrr	p15, 4, rr_lo_hi(r2, r3), c2



	@ Set the HTCR and VTCR to the same shareability and cacheability

	@ settings as the non-secure TTBCR and with T0SZ == 0.
@@ -137,7 +137,7 @@ phase2: 
	mov	pc, r0



target:	@ We're now in the trampoline code, switch page tables

	mcrr	p15, 4, r2, r3, c2

	mcrr	p15, 4, rr_lo_hi(r2, r3), c2

	isb



	@ Invalidate the old TLBs

arch/arm/kvm/interrupts.S

+2 −2
Original line number Diff line number Diff line
@@ -52,7 +52,7 @@ ENTRY(__kvm_tlb_flush_vmid_ipa) 
	dsb	ishst

	add	r0, r0, #KVM_VTTBR

	ldrd	r2, r3, [r0]

	mcrr	p15, 6, r2, r3, c2	@ Write VTTBR

	mcrr	p15, 6, rr_lo_hi(r2, r3), c2	@ Write VTTBR

	isb

	mcr     p15, 0, r0, c8, c3, 0	@ TLBIALLIS (rt ignored)

	dsb	ish
@@ -135,7 +135,7 @@ ENTRY(__kvm_vcpu_run) 
	ldr	r1, [vcpu, #VCPU_KVM]

	add	r1, r1, #KVM_VTTBR

	ldrd	r2, r3, [r1]

	mcrr	p15, 6, r2, r3, c2	@ Write VTTBR

	mcrr	p15, 6, rr_lo_hi(r2, r3), c2	@ Write VTTBR



	@ We're all done, just restore the GPRs and go to the guest

	restore_guest_regs

arch/arm/kvm/interrupts_head.S

+3 −3
Original line number Diff line number Diff line
@@ -520,7 +520,7 @@ ARM_BE8(rev r6, r6 ) 
	mcr	p15, 0, r2, c14, c3, 1	@ CNTV_CTL

	isb



	mrrc	p15, 3, r2, r3, c14	@ CNTV_CVAL

	mrrc	p15, 3, rr_lo_hi(r2, r3), c14	@ CNTV_CVAL

	ldr	r4, =VCPU_TIMER_CNTV_CVAL

	add	r5, vcpu, r4

	strd	r2, r3, [r5]
@@ -560,12 +560,12 @@ ARM_BE8(rev r6, r6 ) 


	ldr	r2, [r4, #KVM_TIMER_CNTVOFF]

	ldr	r3, [r4, #(KVM_TIMER_CNTVOFF + 4)]

	mcrr	p15, 4, r2, r3, c14	@ CNTVOFF

	mcrr	p15, 4, rr_lo_hi(r2, r3), c14	@ CNTVOFF



	ldr	r4, =VCPU_TIMER_CNTV_CVAL

	add	r5, vcpu, r4

	ldrd	r2, r3, [r5]

	mcrr	p15, 3, r2, r3, c14	@ CNTV_CVAL

	mcrr	p15, 3, rr_lo_hi(r2, r3), c14	@ CNTV_CVAL

	isb



	ldr	r2, [vcpu, #VCPU_TIMER_CNTV_CTL]

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