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authorRussell King <rmk+kernel@arm.linux.org.uk>2010-09-04 11:47:48 +0200
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-10-04 21:23:36 +0200
commitf00ec48fadf5e37e7889f14cff900aa70d18b644 (patch)
tree421cbce97167a78532aa825624f380caade3c0d2 /arch/arm/mm/cache-v7.S
parentARM: Provide common header for hard_smp_processor_id() (diff)
downloadlinux-f00ec48fadf5e37e7889f14cff900aa70d18b644.tar.xz
linux-f00ec48fadf5e37e7889f14cff900aa70d18b644.zip
ARM: Allow SMP kernels to boot on UP systems
UP systems do not implement all the instructions that SMP systems have, so in order to boot a SMP kernel on a UP system, we need to rewrite parts of the kernel. Do this using an 'alternatives' scheme, where the kernel code and data is modified prior to initialization to replace the SMP instructions, thereby rendering the problematical code ineffectual. We use the linker to generate a list of 32-bit word locations and their replacement values, and run through these replacements when we detect a UP system. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/cache-v7.S')
-rw-r--r--arch/arm/mm/cache-v7.S14
1 files changed, 4 insertions, 10 deletions
diff --git a/arch/arm/mm/cache-v7.S b/arch/arm/mm/cache-v7.S
index 37c8157e116e..e8ea1a071f43 100644
--- a/arch/arm/mm/cache-v7.S
+++ b/arch/arm/mm/cache-v7.S
@@ -91,11 +91,8 @@ ENTRY(v7_flush_kern_cache_all)
THUMB( stmfd sp!, {r4-r7, r9-r11, lr} )
bl v7_flush_dcache_all
mov r0, #0
-#ifdef CONFIG_SMP
- mcr p15, 0, r0, c7, c1, 0 @ invalidate I-cache inner shareable
-#else
- mcr p15, 0, r0, c7, c5, 0 @ I+BTB cache invalidate
-#endif
+ ALT_SMP(mcr p15, 0, r0, c7, c1, 0) @ invalidate I-cache inner shareable
+ ALT_UP(mcr p15, 0, r0, c7, c5, 0) @ I+BTB cache invalidate
ARM( ldmfd sp!, {r4-r5, r7, r9-r11, lr} )
THUMB( ldmfd sp!, {r4-r7, r9-r11, lr} )
mov pc, lr
@@ -171,11 +168,8 @@ ENTRY(v7_coherent_user_range)
cmp r0, r1
blo 1b
mov r0, #0
-#ifdef CONFIG_SMP
- mcr p15, 0, r0, c7, c1, 6 @ invalidate BTB Inner Shareable
-#else
- mcr p15, 0, r0, c7, c5, 6 @ invalidate BTB
-#endif
+ ALT_SMP(mcr p15, 0, r0, c7, c1, 6) @ invalidate BTB Inner Shareable
+ ALT_UP(mcr p15, 0, r0, c7, c5, 6) @ invalidate BTB
dsb
isb
mov pc, lr