ARM: 6795/1: l2x0: Errata fix for flush by Way operation can cause data corrupti

PL310 implements the Clean & Invalidate by Way L2 cache maintenance
operation (offset 0x7FC). This operation runs in background so that
PL310 can handle normal accesses while it is in progress. Under very
rare circumstances, due to this erratum, write data can be lost when
PL310 treats a cacheable write transaction during a Clean & Invalidate
by Way operation.

Workaround:
Disable Write-Back and Cache Linefill (Debug Control Register)
Clean & Invalidate by Way (0x7FC)
Re-enable Write-Back and Cache Linefill (Debug Control Register)

This patch also removes any OMAP dependency on PL310 Errata's

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 170c9bb..803bce8 100644
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -67,18 +67,24 @@
 	writel_relaxed(addr, base + L2X0_INV_LINE_PA);
 }
 
-#ifdef CONFIG_PL310_ERRATA_588369
-static void debug_writel(unsigned long val)
-{
-	extern void omap_smc1(u32 fn, u32 arg);
+#if defined(CONFIG_PL310_ERRATA_588369) || defined(CONFIG_PL310_ERRATA_727915)
 
-	/*
-	 * Texas Instrument secure monitor api to modify the
-	 * PL310 Debug Control Register.
-	 */
-	omap_smc1(0x100, val);
+#define debug_writel(val)	outer_cache.set_debug(val)
+
+static void l2x0_set_debug(unsigned long val)
+{
+	writel_relaxed(val, l2x0_base + L2X0_DEBUG_CTRL);
+}
+#else
+/* Optimised out for non-errata case */
+static inline void debug_writel(unsigned long val)
+{
 }
 
+#define l2x0_set_debug	NULL
+#endif
+
+#ifdef CONFIG_PL310_ERRATA_588369
 static inline void l2x0_flush_line(unsigned long addr)
 {
 	void __iomem *base = l2x0_base;
@@ -91,11 +97,6 @@
 }
 #else
 
-/* Optimised out for non-errata case */
-static inline void debug_writel(unsigned long val)
-{
-}
-
 static inline void l2x0_flush_line(unsigned long addr)
 {
 	void __iomem *base = l2x0_base;
@@ -119,9 +120,11 @@
 
 	/* clean all ways */
 	spin_lock_irqsave(&l2x0_lock, flags);
+	debug_writel(0x03);
 	writel_relaxed(l2x0_way_mask, l2x0_base + L2X0_CLEAN_INV_WAY);
 	cache_wait_way(l2x0_base + L2X0_CLEAN_INV_WAY, l2x0_way_mask);
 	cache_sync();
+	debug_writel(0x00);
 	spin_unlock_irqrestore(&l2x0_lock, flags);
 }
 
@@ -329,6 +332,7 @@
 	outer_cache.flush_all = l2x0_flush_all;
 	outer_cache.inv_all = l2x0_inv_all;
 	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",