ARM: tegra: set up the correct L2 data RAM latency for Cortex-A15

When there is a cluster power down cycle in suspend, we need to set up
the correct L2 RAM data RAM latency to make L2 cache work correctly. This
is only needed for cluster 0 and needs to be done in tegra_resume before
the cache is enabled.

Signed-off-by: Joseph Lo <josephl@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>

arch/arm/mach-tegra/reset-handler.S

@@ -45,6 +45,7 @@
 ENTRY(tegra_resume)
 	check_cpu_part_num 0xc09, r8, r9
 	bleq	v7_invalidate_l1
+	blne	tegra_init_l2_for_a15
 
 	cpu_id	r0
 	tegra_get_soc_id TEGRA_APB_MISC_BASE, r6

arch/arm/mach-tegra/sleep.S

@@ -68,6 +68,28 @@ ENDPROC(tegra_disable_clean_inv_dcache)
 #endif
 
 #ifdef CONFIG_PM_SLEEP
+/*
+ * tegra_init_l2_for_a15
+ *
+ * set up the correct L2 cache data RAM latency
+ */
+ENTRY(tegra_init_l2_for_a15)
+	mrc	p15, 0, r0, c0, c0, 5
+	ubfx	r0, r0, #8, #4
+	tst	r0, #1				@ only need for cluster 0
+	bne	_exit_init_l2_a15
+
+	mrc	p15, 0x1, r0, c9, c0, 2
+	and	r0, r0, #7
+	cmp	r0, #2
+	bicne	r0, r0, #7
+	orrne	r0, r0, #2
+	mcrne	p15, 0x1, r0, c9, c0, 2
+_exit_init_l2_a15:
+
+	mov	pc, lr
+ENDPROC(tegra_init_l2_for_a15)
+
 /*
  * tegra_sleep_cpu_finish(unsigned long v2p)
  *