| Message ID | 1399997646-4716-4-git-send-email-victor.kamensky@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 13, 2014 at 09:13:55AM -0700, Victor Kamensky wrote: > 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. So in this version you decided to keep the ordering of the TTBRX and TTBRX_high bits (high being most significant). I assume this is because of the trapping of VM registers introduced by mark and to maintain access_vm_reg()? Any other changes since the last version? If none, then for the content of this patch: Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
On 13/05/14 17:13, Victor Kamensky wrote: > 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: Victor Kamensky <victor.kamensky@linaro.org> > --- > arch/arm/include/asm/kvm_asm.h | 18 ++++++++++++++++++ > arch/arm/kvm/init.S | 4 ++-- > arch/arm/kvm/interrupts.S | 4 ++-- > arch/arm/kvm/interrupts_head.S | 6 +++--- > 4 files changed, 25 insertions(+), 7 deletions(-) > > diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h > index 53b3c4a..3a67bec 100644 > --- a/arch/arm/include/asm/kvm_asm.h > +++ b/arch/arm/include/asm/kvm_asm.h > @@ -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; > diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S > index 74f0718..2d10b2d 100644 > --- a/arch/arm/kvm/init.S > +++ b/arch/arm/kvm/init.S > @@ -74,7 +74,7 @@ __do_hyp_init: > ARM_BE8(setend be) @ Switch to Big Endian mode if needed > > @ 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. > @@ -140,7 +140,7 @@ 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 > diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S > index 0d68d40..24d4e65 100644 > --- a/arch/arm/kvm/interrupts.S > +++ b/arch/arm/kvm/interrupts.S > @@ -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 > diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S > index e627858..104977f 100644 > --- a/arch/arm/kvm/interrupts_head.S > +++ b/arch/arm/kvm/interrupts_head.S > @@ -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] > As much as I hate the macro, I can't find a better solution. As such: Acked-by: Marc Zyngier <marc.zyngier@arm.com> M.
On 26 May 2014 08:28, Christoffer Dall <christoffer.dall@linaro.org> wrote: > On Tue, May 13, 2014 at 09:13:55AM -0700, Victor Kamensky wrote: >> 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. > > So in this version you decided to keep the ordering of the TTBRX and > TTBRX_high bits (high being most significant). I assume this is because > of the trapping of VM registers introduced by mark and to maintain > access_vm_reg()? Yes, that is correct. > Any other changes since the last version? No > If none, then for the content of this patch: > > Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Thanks, Victor
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h index 53b3c4a..3a67bec 100644 --- a/arch/arm/include/asm/kvm_asm.h +++ b/arch/arm/include/asm/kvm_asm.h @@ -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; diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S index 74f0718..2d10b2d 100644 --- a/arch/arm/kvm/init.S +++ b/arch/arm/kvm/init.S @@ -74,7 +74,7 @@ __do_hyp_init: ARM_BE8(setend be) @ Switch to Big Endian mode if needed @ 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. @@ -140,7 +140,7 @@ 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 diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S index 0d68d40..24d4e65 100644 --- a/arch/arm/kvm/interrupts.S +++ b/arch/arm/kvm/interrupts.S @@ -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 diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S index e627858..104977f 100644 --- a/arch/arm/kvm/interrupts_head.S +++ b/arch/arm/kvm/interrupts_head.S @@ -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]
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: Victor Kamensky <victor.kamensky@linaro.org> --- arch/arm/include/asm/kvm_asm.h | 18 ++++++++++++++++++ arch/arm/kvm/init.S | 4 ++-- arch/arm/kvm/interrupts.S | 4 ++-- arch/arm/kvm/interrupts_head.S | 6 +++--- 4 files changed, 25 insertions(+), 7 deletions(-)