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-rw-r--r--arch/arm/mach-tegra/headsmp.S61
1 files changed, 61 insertions, 0 deletions
diff --git a/arch/arm/mach-tegra/headsmp.S b/arch/arm/mach-tegra/headsmp.S
new file mode 100644
index 00000000000..b5349b2f13d
--- /dev/null
+++ b/arch/arm/mach-tegra/headsmp.S
@@ -0,0 +1,61 @@
+#include <linux/linkage.h>
+#include <linux/init.h>
+
+ .section ".text.head", "ax"
+ __CPUINIT
+
+/*
+ * Tegra specific entry point for secondary CPUs.
+ * 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.
+ */
+ENTRY(v7_invalidate_l1)
+ mov r0, #0
+ 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(tegra_secondary_startup)
+ msr cpsr_fsxc, #0xd3
+ bl v7_invalidate_l1
+ mrc p15, 0, r0, c0, c0, 5
+ and r0, r0, #15
+ ldr r1, =0x6000f100
+ str r0, [r1]
+1: ldr r2, [r1]
+ cmp r0, r2
+ beq 1b
+ b secondary_startup
+ENDPROC(tegra_secondary_startup)