MIPS: BCM63xx: Fix SDRAM size computation for BCM6345

Instead of hardcoding the amount of available RAM, read the number of
effective multiples of 8MB from SDRAM_MBASE_REG.
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3008/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/bcm63xx/cpu.c

@@ -170,8 +170,10 @@ static unsigned int detect_memory_size(void)
 	unsigned int cols = 0, rows = 0, is_32bits = 0, banks = 0;
 	u32 val;
 
-	if (BCMCPU_IS_6345())
-		return (8 * 1024 * 1024);
+	if (BCMCPU_IS_6345()) {
+		val = bcm_sdram_readl(SDRAM_MBASE_REG);
+		return (val * 8 * 1024 * 1024);
+	}
 
 	if (BCMCPU_IS_6338() || BCMCPU_IS_6348()) {
 		val = bcm_sdram_readl(SDRAM_CFG_REG);

arch/mips/include/asm/mach-bcm63xx/bcm63xx_regs.h

@@ -895,6 +895,8 @@
 #define SDRAM_CFG_BANK_SHIFT		13
 #define SDRAM_CFG_BANK_MASK		(1 << SDRAM_CFG_BANK_SHIFT)
 
+#define SDRAM_MBASE_REG			0xc
+
 #define SDRAM_PRIO_REG			0x2C
 #define SDRAM_PRIO_MIPS_SHIFT		29
 #define SDRAM_PRIO_MIPS_MASK		(1 << SDRAM_PRIO_MIPS_SHIFT)