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authorRobin Murphy <robin.murphy@arm.com>2016-08-19 19:38:41 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2016-08-23 10:08:33 +0100
commit1527eda3ab290f4ab519fe495c70ede5b0ad699f (patch)
tree2ac653646115e4bf534eae1aebfebcf4b9e86186
parentf271b779f415455e904f3f10067ab7f2fb8af497 (diff)
downloadop-kernel-dev-1527eda3ab290f4ab519fe495c70ede5b0ad699f.zip
op-kernel-dev-1527eda3ab290f4ab519fe495c70ede5b0ad699f.tar.gz
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 <linux@armlinux.org.uk> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/kernel/hyp-stub.S13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm/kernel/hyp-stub.S b/arch/arm/kernel/hyp-stub.S
index 0b1e4a9..15d073a 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
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