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ARM: smp_on_up: allow non-ARM SMP processors 

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.

Cc: <stable@kernel.org>
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>
This commit is contained in:
Russell King 2011-01-30 16:40:20 +00:00
parent c1928022ef
commit e98ff0f55a
1 changed files with 10 additions and 12 deletions
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22
arch/arm/kernel/head.S
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@ -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