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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-12 17:27:41 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-12 17:27:41 -0700
commit5889fc32171a41d2f306bba320715b72655dcb1a (patch)
tree7bec4883544f504664a01a600688d8fd963c2a7d /arch/arm/mach-shmobile/headsmp.S
parent1bc4a5be0acbd16de4df6e4fb73a76fa92e9a521 (diff)
parent85d5c4a362add39f7491b38ed0160df1dcae1d2b (diff)
Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM: SoC fixes from Olof Johansson: "I was hoping to be done with fixes for 3.4 but we got two branches from subarch maintainers the last couple of days. So here is one last(?) pull request for arm-soc containing 7 patches: - Five of them are for shmobile dealing with SMP setup and compile failures - The remaining two are for regressions on the Samsung platforms" * tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: ARM: EXYNOS: fix ctrlbit for exynos5_clk_pdma1 ARM: EXYNOS: use s5p-timer for UniversalC210 board ARM / mach-shmobile: Invalidate caches when booting secondary cores ARM / mach-shmobile: sh73a0 SMP TWD boot regression fix ARM / mach-shmobile: r8a7779 SMP TWD boot regression fix ARM: mach-shmobile: convert ag5evm to use the generic MMC GPIO hotplug helper ARM: mach-shmobile: convert mackerel to use the generic MMC GPIO hotplug helper
Diffstat (limited to 'arch/arm/mach-shmobile/headsmp.S')
-rw-r--r--arch/arm/mach-shmobile/headsmp.S56
1 files changed, 55 insertions, 1 deletions
diff --git a/arch/arm/mach-shmobile/headsmp.S b/arch/arm/mach-shmobile/headsmp.S
index 6ac015c89206..b202c1272526 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)