[PATCH v2 04/28] ARM: mm: cache-l2x0: Add support for re-enabling l2x0

[ccross@android.com (Colin Cross)]

Remove __init annotation from l2x0_init so it can be used to
reinitialize the l2x0 after it has been reset during suspend.

Add l2x0_enable to re-enable the l2x0 after l2x0_disable if
the l2x0 was not reset.

l2x0_disable cannot use writel, as writel calls wmb(), and wmb()
may call outer_cache_sync, which takes the same spinlock as
l2x0_disable.

Signed-off-by: Colin Cross <ccross@android.com>
---
 arch/arm/include/asm/hardware/cache-l2x0.h |    3 ++-
 arch/arm/mm/cache-l2x0.c                   |   14 ++++++++++++--
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/hardware/cache-l2x0.h b/arch/arm/include/asm/hardware/cache-l2x0.h
index 5aeec1e..2b4479f 100644
--- a/arch/arm/include/asm/hardware/cache-l2x0.h
+++ b/arch/arm/include/asm/hardware/cache-l2x0.h
@@ -72,7 +72,8 @@
 #define L2X0_AUX_CTRL_EARLY_BRESP_SHIFT		30
 
 #ifndef __ASSEMBLY__
-extern void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask);
+extern void l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask);
+extern void l2x0_enable(void);
 #endif
 
 #endif
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 170c9bb..e525449 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -252,16 +252,26 @@ static void l2x0_flush_range(unsigned long start, unsigned long end)
 	spin_unlock_irqrestore(&l2x0_lock, flags);
 }
 
+/* enables l2x0 after l2x0_disable, does not invalidate */
+void l2x0_enable(void)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&l2x0_lock, flags);
+	writel_relaxed(1, l2x0_base + L2X0_CTRL);
+	spin_unlock_irqrestore(&l2x0_lock, flags);
+}
+
 static void l2x0_disable(void)
 {
 	unsigned long flags;
 
 	spin_lock_irqsave(&l2x0_lock, flags);
-	writel(0, l2x0_base + L2X0_CTRL);
+	writel_relaxed(0, l2x0_base + L2X0_CTRL);
 	spin_unlock_irqrestore(&l2x0_lock, flags);
 }
 
-void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
+void l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
 {
 	__u32 aux;
 	__u32 cache_id;
-- 
1.7.3.1