[PATCH] ARM: mm: cache-l2x0: Add support for re-enabling l2x0

Colin Cross ccross at android.com
Sun Jun 12 20:46:58 EDT 2011

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

Only print the init messages the first time l2x0_init is called.

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

Signed-off-by: Colin Cross <ccross at android.com>
 arch/arm/include/asm/hardware/cache-l2x0.h |    3 ++-
 arch/arm/mm/cache-l2x0.c                   |   18 ++++++++++++++----
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/arch/arm/include/asm/hardware/cache-l2x0.h b/arch/arm/include/asm/hardware/cache-l2x0.h
index 16bd480..8fd87fe 100644
--- a/arch/arm/include/asm/hardware/cache-l2x0.h
+++ b/arch/arm/include/asm/hardware/cache-l2x0.h
@@ -73,7 +73,8 @@
 #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);
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index ef59099..4db0d9c 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -261,16 +261,26 @@ 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;
@@ -340,7 +350,7 @@ void __init l2x0_init(void __iomem *base, __u32 aux_val, __u32 aux_mask)
 	outer_cache.disable = l2x0_disable;
 	outer_cache.set_debug = l2x0_set_debug;
-	printk(KERN_INFO "%s cache controller enabled\n", type);
-	printk(KERN_INFO "l2x0: %d ways, CACHE_ID 0x%08x, AUX_CTRL 0x%08x, Cache size: %d B\n",
+	pr_info_once("%s cache controller enabled\n", type);
+	pr_info_once("l2x0: %d ways, CACHE_ID 0x%08x, AUX_CTRL 0x%08x, Cache size: %d B\n",
 			ways, cache_id, aux, l2x0_size);

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