[PATCH v4 4/4] mips: bmips: enable RAC on BMIPS4350

[Christian Marangi <ansuelsmth@gmail.com>]

From: Daniel González Cabanelas <dgcbueu@gmail.com>

The data RAC is left disabled by the bootloader in some SoCs, at least in
the core it boots from.
Enabling this feature increases the performance up to +30% depending on the
task.

Signed-off-by: Daniel González Cabanelas <dgcbueu@gmail.com>
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
[ rework code and reduce code duplication ]
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
---
 arch/mips/kernel/smp-bmips.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
index 20e2fb10022d..52324738cbb3 100644
--- a/arch/mips/kernel/smp-bmips.c
+++ b/arch/mips/kernel/smp-bmips.c
@@ -626,6 +626,23 @@ void bmips_cpu_setup(void)
 		__raw_readl(cbr + BMIPS_RAC_ADDRESS_RANGE);
 		break;
 
+	case CPU_BMIPS4350:
+		u32 rac_addr = BMIPS_RAC_CONFIG_1;
+
+		if (!(read_c0_brcm_cmt_local() & (1 << 31)))
+			rac_addr = BMIPS_RAC_CONFIG;
+
+		/* Enable data RAC */
+		cfg = __raw_readl(cbr + rac_addr);
+		__raw_writel(cfg | 0xf, cbr + rac_addr);
+		__raw_readl(cbr + rac_addr);
+
+		/* Flush stale data out of the readahead cache */
+		cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG);
+		__raw_writel(cfg | 0x100, cbr + BMIPS_RAC_CONFIG);
+		__raw_readl(cbr + BMIPS_RAC_CONFIG);
+		break;
+
 	case CPU_BMIPS4380:
 		/* CBG workaround for early BMIPS4380 CPUs */
 		switch (read_c0_prid()) {
-- 
2.43.0