Commit e98ff0f5 authored by Russell King's avatar Russell King

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: default avatarStephen Boyd <sboyd@codeaurora.org>
Acked-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent c1928022
...@@ -392,24 +392,22 @@ ENDPROC(__turn_mmu_on) ...@@ -392,24 +392,22 @@ ENDPROC(__turn_mmu_on)
#ifdef CONFIG_SMP_ON_UP #ifdef CONFIG_SMP_ON_UP
__fixup_smp: __fixup_smp:
mov r4, #0x00070000 and r3, r9, #0x000f0000 @ architecture version
orr r3, r4, #0xff000000 @ mask 0xff070000 teq r3, #0x000f0000 @ CPU ID supported?
orr r4, r4, #0x41000000 @ val 0x41070000
and r0, r9, r3
teq r0, r4 @ ARM CPU and ARMv6/v7?
bne __fixup_smp_on_up @ no, assume UP bne __fixup_smp_on_up @ no, assume UP
orr r3, r3, #0x0000ff00 bic r3, r9, #0x00ff0000
orr r3, r3, #0x000000f0 @ mask 0xff07fff0 bic r3, r3, #0x0000000f @ mask 0xff00fff0
mov r4, #0x41000000
orr r4, r4, #0x0000b000 orr r4, r4, #0x0000b000
orr r4, r4, #0x00000020 @ val 0x4107b020 orr r4, r4, #0x00000020 @ val 0x4100b020
and r0, r9, r3 teq r3, r4 @ ARM 11MPCore?
teq r0, r4 @ ARM 11MPCore?
moveq pc, lr @ yes, assume SMP moveq pc, lr @ yes, assume SMP
mrc p15, 0, r0, c0, c0, 5 @ read MPIDR mrc p15, 0, r0, c0, c0, 5 @ read MPIDR
tst r0, #1 << 31 and r0, r0, #0xc0000000 @ multiprocessing extensions and
movne pc, lr @ bit 31 => SMP teq r0, #0x80000000 @ not part of a uniprocessor system?
moveq pc, lr @ yes, assume SMP
__fixup_smp_on_up: __fixup_smp_on_up:
adr r0, 1f adr r0, 1f
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment