ARM926EJS: Implement cache operations

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/arch/arm/cpu/arm926ejs/cache.c b/arch/arm/cpu/arm926ejs/cache.c
index 504f604..5b23e3a 100644
--- a/arch/arm/cpu/arm926ejs/cache.c
+++ b/arch/arm/cpu/arm926ejs/cache.c
@@ -23,29 +23,71 @@
 #include <common.h>
 
 #ifndef CONFIG_SYS_DCACHE_OFF
-static inline void dcache_noop(void)
+
+#ifndef CONFIG_SYS_CACHELINE_SIZE
+#define CONFIG_SYS_CACHELINE_SIZE	32
+#endif
+
+void invalidate_dcache_all(void)
 {
-	if (dcache_status()) {
-		puts("WARNING: cache operations are not implemented!\n"
-		     "WARNING: disabling D-Cache now, you can re-enable it"
-		     "later with 'dcache on' command\n");
-		dcache_disable();
-	}
+	asm volatile("mcr p15, 0, %0, c7, c6, 0\n"::"r"(0));
 }
 
-void invalidate_dcache_all(void)
+void flush_dcache_all(void)
 {
-	dcache_noop();
+	asm volatile(
+		"0:"
+		"mrc p15, 0, r15, c7, c14, 3\n"
+		"bne 0b\n"
+		"mcr p15, 0, %0, c7, c10, 4\n"
+		::"r"(0):"memory"
+	);
 }
 
+static int check_cache_range(unsigned long start, unsigned long stop)
+{
+	int ok = 1;
+
+	if (start & (CONFIG_SYS_CACHELINE_SIZE - 1))
+		ok = 0;
+
+	if (stop & (CONFIG_SYS_CACHELINE_SIZE - 1))
+		ok = 0;
+
+	if (!ok)
+		printf("CACHE: Misaligned operation at range [%08lx, %08lx]\n",
+			start, stop);
+
+	return ok;
+}
+
 void invalidate_dcache_range(unsigned long start, unsigned long stop)
 {
-	dcache_noop();
+	if (!check_cache_range(start, stop))
+		return;
+
+	while (start < stop) {
+		asm volatile("mcr p15, 0, %0, c7, c6, 1\n"::"r"(start));
+		start += CONFIG_SYS_CACHELINE_SIZE;
+	}
 }
 
 void flush_dcache_range(unsigned long start, unsigned long stop)
 {
+	if (!check_cache_range(start, stop))
+		return;
+
+	while (start < stop) {
+		asm volatile("mcr p15, 0, %0, c7, c14, 1\n"::"r"(start));
+		start += CONFIG_SYS_CACHELINE_SIZE;
+	}
+
+	asm("mcr p15, 0, %0, c7, c10, 4\n"::"r"(0));
+}
+
+void flush_cache(unsigned long start, unsigned long size)
+{
-	dcache_noop();
+	flush_dcache_range(start, start + size);
 }
 #else /* #ifndef CONFIG_SYS_DCACHE_OFF */
 void invalidate_dcache_all(void)
@@ -64,7 +106,7 @@
 {
 }
 
-void  flush_cache(unsigned long start, unsigned long size)
+void flush_cache(unsigned long start, unsigned long size)
 {
 }
 #endif /* #ifndef CONFIG_SYS_DCACHE_OFF */