ARM: B15: Update to support Brahma-B53

The B53 CPU design supports up to 8 processors, which moved the RAC_FLUSH_REG
offset 0x4 bytes below to make room for a RAC_CONFIG2_REG to control RAC
settings for CPU4-7.

Lookup the processor type (B15 or B53) and adjust the RAC_FLUSH_REG offset
accordingly, if we do not know the processor, bail out.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

arch/arm/mm/cache-b15-rac.c

@@ -33,7 +33,10 @@ extern void v7_flush_kern_cache_all(void);
 #define  RAC_CPU_SHIFT			(8)
 #define  RACCFG_MASK			(0xff)
 #define RAC_CONFIG1_REG			(0x7c)
-#define RAC_FLUSH_REG			(0x80)
+/* Brahma-B15 is a quad-core only design */
+#define B15_RAC_FLUSH_REG		(0x80)
+/* Brahma-B53 is an octo-core design */
+#define B53_RAC_FLUSH_REG		(0x84)
 #define  FLUSH_RAC			(1 << 0)
 
 /* Bitmask to enable instruction and data prefetching with a 256-bytes stride */
@@ -52,6 +55,7 @@ static void __iomem *b15_rac_base;
 static DEFINE_SPINLOCK(rac_lock);
 
 static u32 rac_config0_reg;
+static u32 rac_flush_offset;
 
 /* Initialization flag to avoid checking for b15_rac_base, and to prevent
  * multi-platform kernels from crashing here as well.
@@ -70,14 +74,14 @@ static inline void __b15_rac_flush(void)
 {
 	u32 reg;
 
-	__raw_writel(FLUSH_RAC, b15_rac_base + RAC_FLUSH_REG);
+	__raw_writel(FLUSH_RAC, b15_rac_base + rac_flush_offset);
 	do {
 		/* This dmb() is required to force the Bus Interface Unit
 		 * to clean oustanding writes, and forces an idle cycle
 		 * to be inserted.
 		 */
 		dmb();
-		reg = __raw_readl(b15_rac_base + RAC_FLUSH_REG);
+		reg = __raw_readl(b15_rac_base + rac_flush_offset);
 	} while (reg & FLUSH_RAC);
 }
 
@@ -287,7 +291,7 @@ static struct syscore_ops b15_rac_syscore_ops = {
 
 static int __init b15_rac_init(void)
 {
-	struct device_node *dn;
+	struct device_node *dn, *cpu_dn;
 	int ret = 0, cpu;
 	u32 reg, en_mask = 0;
 
@@ -305,6 +309,24 @@ static int __init b15_rac_init(void)
 		goto out;
 	}
 
+	cpu_dn = of_get_cpu_node(0, NULL);
+	if (!cpu_dn) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	if (of_device_is_compatible(cpu_dn, "brcm,brahma-b15"))
+		rac_flush_offset = B15_RAC_FLUSH_REG;
+	else if (of_device_is_compatible(cpu_dn, "brcm,brahma-b53"))
+		rac_flush_offset = B53_RAC_FLUSH_REG;
+	else {
+		pr_err("Unsupported CPU\n");
+		of_node_put(cpu_dn);
+		ret = -EINVAL;
+		goto out;
+	}
+	of_node_put(cpu_dn);
+
 	ret = register_reboot_notifier(&b15_rac_reboot_nb);
 	if (ret) {
 		pr_err("failed to register reboot notifier\n");