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authorRussell King <rmk+kernel@arm.linux.org.uk>2011-01-30 16:40:20 +0000
committerGreg Kroah-Hartman <gregkh@suse.de>2011-02-17 15:14:44 -0800
commitb770e599b231a81cf53e00beee29261cfc8be46c (patch)
treed5b72d90fdc0aa1f781ae2cf839e7bc26a348ab9 /arch
parent3eb02dfd31bf0d6ada5c78a4136b215144871011 (diff)
ARM: smp_on_up: allow non-ARM SMP processors
commit e98ff0f55a0232b578c9aa7f1c245868277ac7bc upstream. Allow non-ARM SMP processors to use the SMP_ON_UP feature. CPUs supporting SMP must have the new CPU ID format, so check for this first. Then check for ARM11MPCore, which fails the MPIDR check. Lastly check the MPIDR reports multiprocessing extensions and that the CPU is part of a multiprocessing system. Reported-and-Tested-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/kernel/head.S22
1 files changed, 10 insertions, 12 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index f25ab9d8f998..7306b8e19add 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -392,24 +392,22 @@ ENDPROC(__turn_mmu_on)
#ifdef CONFIG_SMP_ON_UP
__fixup_smp:
- mov r4, #0x00070000
- orr r3, r4, #0xff000000 @ mask 0xff070000
- orr r4, r4, #0x41000000 @ val 0x41070000
- and r0, r9, r3
- teq r0, r4 @ ARM CPU and ARMv6/v7?
+ and r3, r9, #0x000f0000 @ architecture version
+ teq r3, #0x000f0000 @ CPU ID supported?
bne __fixup_smp_on_up @ no, assume UP
- orr r3, r3, #0x0000ff00
- orr r3, r3, #0x000000f0 @ mask 0xff07fff0
+ bic r3, r9, #0x00ff0000
+ bic r3, r3, #0x0000000f @ mask 0xff00fff0
+ mov r4, #0x41000000
orr r4, r4, #0x0000b000
- orr r4, r4, #0x00000020 @ val 0x4107b020
- and r0, r9, r3
- teq r0, r4 @ ARM 11MPCore?
+ orr r4, r4, #0x00000020 @ val 0x4100b020
+ teq r3, r4 @ ARM 11MPCore?
moveq pc, lr @ yes, assume SMP
mrc p15, 0, r0, c0, c0, 5 @ read MPIDR
- tst r0, #1 << 31
- movne pc, lr @ bit 31 => SMP
+ and r0, r0, #0xc0000000 @ multiprocessing extensions and
+ teq r0, #0x80000000 @ not part of a uniprocessor system?
+ moveq pc, lr @ yes, assume SMP
__fixup_smp_on_up:
adr r0, 1f