[PATCH 3.13 086/103] ARM/ARM64: KVM: Nuke Hyp-mode tlbs before enabling MMU

From: Kamal Mostafa
Date: Tue Sep 30 2014 - 17:41:52 EST -stable review patch. If anyone has any objections, please let me know.


From: Pranavkumar Sawargaonkar <pranavkumar@xxxxxxxxxx>

commit f6edbbf36da3a27b298b66c7955fc84e1dcca305 upstream.

X-Gene u-boot runs in EL2 mode with MMU enabled hence we might
have stale EL2 tlb enteris when we enable EL2 MMU on each host CPU.

This can happen on any ARM/ARM64 board running bootloader in
Hyp-mode (or EL2-mode) with MMU enabled.

This patch ensures that we flush all Hyp-mode (or EL2-mode) TLBs
on each host CPU before enabling Hyp-mode (or EL2-mode) MMU.

Tested-by: Mark Rutland <mark.rutland@xxxxxxx>
Reviewed-by: Marc Zyngier <marc.zyngier@xxxxxxx>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@xxxxxxxxxx>
Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxx>
Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
arch/arm/kvm/init.S | 4 ++++
arch/arm64/kvm/hyp-init.S | 4 ++++
2 files changed, 8 insertions(+)

diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
index 1b9844d..ee4f744 100644
--- a/arch/arm/kvm/init.S
+++ b/arch/arm/kvm/init.S
@@ -98,6 +98,10 @@ __do_hyp_init:
mrc p15, 0, r0, c10, c2, 1
mcr p15, 4, r0, c10, c2, 1

+ @ Invalidate the stale TLBs from Bootloader
+ mcr p15, 4, r0, c8, c7, 0 @ TLBIALLH
+ dsb ish
@ Set the HSCTLR to:
@ - ARM/THUMB exceptions: Kernel config (Thumb-2 kernel)
@ - Endianness: Kernel config
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 2b0244d..12e26f3 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -74,6 +74,10 @@ __do_hyp_init:
msr mair_el2, x4

+ /* Invalidate the stale TLBs from Bootloader */
+ tlbi alle2
+ dsb sy
mrs x4, sctlr_el2
and x4, x4, #SCTLR_EL2_EE // preserve endianness of EL2
ldr x5, =SCTLR_EL2_FLAGS

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