diff options
Diffstat (limited to 'arch/arm/mach-shmobile/headsmp.S')
| -rw-r--r-- | arch/arm/mach-shmobile/headsmp.S | 56 |
1 files changed, 55 insertions, 1 deletions
diff --git a/arch/arm/mach-shmobile/headsmp.S b/arch/arm/mach-shmobile/headsmp.S index 6ac015c8920..b202c127252 100644 --- a/arch/arm/mach-shmobile/headsmp.S +++ b/arch/arm/mach-shmobile/headsmp.S @@ -16,6 +16,59 @@ __CPUINIT +/* Cache invalidation nicked from arch/arm/mach-imx/head-v7.S, thanks! + * + * The secondary kernel init calls v7_flush_dcache_all before it enables + * the L1; however, the L1 comes out of reset in an undefined state, so + * the clean + invalidate performed by v7_flush_dcache_all causes a bunch + * of cache lines with uninitialized data and uninitialized tags to get + * written out to memory, which does really unpleasant things to the main + * processor. We fix this by performing an invalidate, rather than a + * clean + invalidate, before jumping into the kernel. + * + * This funciton is cloned from arch/arm/mach-tegra/headsmp.S, and needs + * to be called for both secondary cores startup and primary core resume + * procedures. Ideally, it should be moved into arch/arm/mm/cache-v7.S. + */ +ENTRY(v7_invalidate_l1) + mov r0, #0 + mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache + mcr p15, 2, r0, c0, c0, 0 + mrc p15, 1, r0, c0, c0, 0 + + ldr r1, =0x7fff + and r2, r1, r0, lsr #13 + + ldr r1, =0x3ff + + and r3, r1, r0, lsr #3 @ NumWays - 1 + add r2, r2, #1 @ NumSets + + and r0, r0, #0x7 + add r0, r0, #4 @ SetShift + + clz r1, r3 @ WayShift + add r4, r3, #1 @ NumWays +1: sub r2, r2, #1 @ NumSets-- + mov r3, r4 @ Temp = NumWays +2: subs r3, r3, #1 @ Temp-- + mov r5, r3, lsl r1 + mov r6, r2, lsl r0 + orr r5, r5, r6 @ Reg = (Temp<<WayShift)|(NumSets<<SetShift) + mcr p15, 0, r5, c7, c6, 2 + bgt 2b + cmp r2, #0 + bgt 1b + dsb + isb + mov pc, lr +ENDPROC(v7_invalidate_l1) + +ENTRY(shmobile_invalidate_start) + bl v7_invalidate_l1 + b secondary_startup +ENDPROC(shmobile_invalidate_start) + /* * Reset vector for secondary CPUs. * This will be mapped at address 0 by SBAR register. @@ -24,4 +77,5 @@ .align 12 ENTRY(shmobile_secondary_vector) ldr pc, 1f -1: .long secondary_startup - PAGE_OFFSET + PLAT_PHYS_OFFSET +1: .long shmobile_invalidate_start - PAGE_OFFSET + PLAT_PHYS_OFFSET +ENDPROC(shmobile_secondary_vector) |