diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-11-22 12:06:28 +0000 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2010-12-20 15:08:02 +0000 |
| commit | 0eb0511d176534674600a1986c3c766756288908 (patch) | |
| tree | 28e3625826844913f85aebe22eb1e4e79ecaa167 /arch/arm/kernel/head.S | |
| parent | b54992fe1b4bad7b7488d58b8696e4e8974fdab0 (diff) | |
ARM: SMP: use more sane register allocation for __fixup_smp_on_up
Use r0,r3-r6 rather than r0,r3,r4,r6,r7, which makes it easier to
understand which registers can be modified. Also document which
registers hold values which must be preserved.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/head.S')
| -rw-r--r-- | arch/arm/kernel/head.S | 39 |
1 files changed, 22 insertions, 17 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index dd6b369ac69..fd94e4e82fc 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -89,6 +89,11 @@ ENTRY(stext) bl __lookup_machine_type @ r5=machinfo movs r8, r5 @ invalid machine (r5=0)? beq __error_a @ yes, error 'a' + + /* + * r1 = machine no, r2 = atags, + * r8 = machinfo, r9 = cpuid, r10 = procinfo + */ bl __vet_atags #ifdef CONFIG_SMP_ON_UP bl __fixup_smp @@ -381,19 +386,19 @@ ENDPROC(__turn_mmu_on) #ifdef CONFIG_SMP_ON_UP __fixup_smp: - mov r7, #0x00070000 - orr r6, r7, #0xff000000 @ mask 0xff070000 - orr r7, r7, #0x41000000 @ val 0x41070000 - and r0, r9, r6 - teq r0, r7 @ ARM CPU and ARMv6/v7? + 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? bne __fixup_smp_on_up @ no, assume UP - orr r6, r6, #0x0000ff00 - orr r6, r6, #0x000000f0 @ mask 0xff07fff0 - orr r7, r7, #0x0000b000 - orr r7, r7, #0x00000020 @ val 0x4107b020 - and r0, r9, r6 - teq r0, r7 @ ARM 11MPCore? + orr r3, r3, #0x0000ff00 + orr r3, r3, #0x000000f0 @ mask 0xff07fff0 + orr r4, r4, #0x0000b000 + orr r4, r4, #0x00000020 @ val 0x4107b020 + and r0, r9, r3 + teq r0, r4 @ ARM 11MPCore? moveq pc, lr @ yes, assume SMP mrc p15, 0, r0, c0, c0, 5 @ read MPIDR @@ -402,13 +407,13 @@ __fixup_smp: __fixup_smp_on_up: adr r0, 1f - ldmia r0, {r3, r6, r7} + ldmia r0, {r3 - r5} sub r3, r0, r3 - add r6, r6, r3 - add r7, r7, r3 -2: cmp r6, r7 - ldmia r6!, {r0, r4} - strlo r4, [r0, r3] + add r4, r4, r3 + add r5, r5, r3 +2: cmp r4, r5 + ldmia r4!, {r0, r6} + strlo r6, [r0, r3] blo 2b mov pc, lr ENDPROC(__fixup_smp) |