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authorCatalin Marinas <catalin.marinas@arm.com>2012-01-09 12:24:47 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-01-13 08:56:41 +0000
commit294064f58953f9964e5945424b09c51800330a83 (patch)
treeb0593f1aaa41a96e23140934c1e54cc97020e9a2
parente37051dc7f35de5ce3f64c40852365ff24f2436c (diff)
ARM: 7275/1: LPAE: Check the CPU support for the long descriptor format
This patch adds a check for the presence of the LPAE feature during the CPU initialisation. If not present, it reports an error when CONFIG_DEBUG_LL is enabled. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/kernel/head.S8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 14e277d2ff9..6d579114406 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -99,6 +99,14 @@ ENTRY(stext)
THUMB( it eq ) @ force fixup-able long branch encoding
beq __error_p @ yes, error 'p'
+#ifdef CONFIG_ARM_LPAE
+ mrc p15, 0, r3, c0, c1, 4 @ read ID_MMFR0
+ and r3, r3, #0xf @ extract VMSA support
+ cmp r3, #5 @ long-descriptor translation table format?
+ THUMB( it lo ) @ force fixup-able long branch encoding
+ blo __error_p @ only classic page table format
+#endif
+
#ifndef CONFIG_XIP_KERNEL
adr r3, 2f
ldmia r3, {r4, r8}