From: Robin Murphy Date: Fri, 19 Aug 2016 18:38:41 +0000 (+0100) Subject: ARM: 8600/1: Enforce some NS-SVC initialisation X-Git-Url: http://drtracing.org/?a=commitdiff_plain;h=1527eda3ab290f4ab519fe495c70ede5b0ad699f;p=deliverable%2Flinux.git ARM: 8600/1: Enforce some NS-SVC initialisation Since the non-secure copies of banked registers lack architecturally defined reset values, there is no actual guarantee when entering in Hyp from secure-only firmware that the Non-Secure PL1 state will look the way that kernel entry (in particular the decompressor stub) expects. So far, we've been getting away with it thanks to implementation details of ARMv7 cores and/or bootloader behaviour, but for the sake of forwards compatibility let's try to ensure that we have a minimally sane state before dropping down into it. Cc: Russell King Reviewed-by: Marc Zyngier Reviewed-by: Christoffer Dall Signed-off-by: Robin Murphy Signed-off-by: Russell King --- diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S index 0b1e4a93d67e..15d073ae5da2 100644 --- a/arch/arm/kernel/hyp-stub.S +++ b/arch/arm/kernel/hyp-stub.S @@ -142,6 +142,19 @@ ARM_BE8(orr r7, r7, #(1 << 25)) @ HSCTLR.EE and r7, #0x1f @ Preserve HPMN mcr p15, 4, r7, c1, c1, 1 @ HDCR + @ Make sure NS-SVC is initialised appropriately + mrc p15, 0, r7, c1, c0, 0 @ SCTLR + orr r7, #(1 << 5) @ CP15 barriers enabled + bic r7, #(3 << 7) @ Clear SED/ITD for v8 (RES0 for v7) + bic r7, #(3 << 19) @ WXN and UWXN disabled + mcr p15, 0, r7, c1, c0, 0 @ SCTLR + + mrc p15, 0, r7, c0, c0, 0 @ MIDR + mcr p15, 4, r7, c0, c0, 0 @ VPIDR + + mrc p15, 0, r7, c0, c0, 5 @ MPIDR + mcr p15, 4, r7, c0, c0, 5 @ VMPIDR + #if !defined(ZIMAGE) && defined(CONFIG_ARM_ARCH_TIMER) @ make CNTP_* and CNTPCT accessible from PL1 mrc p15, 0, r7, c0, c1, 1 @ ID_PFR1