[PATCH 09/20] soc: sifive: l2_cache: enable maximum available cache ways

[Ahmad Fatoum]

Previous boot stages may not enable all cache ways, e.g. because they
are running from L2 cache. By the time barebox proper is running,
execution should be from main SDRAM, so it's ok now to enable the
maximum available count of cache ways.

Signed-off-by: Ahmad Fatoum <a.fatoum at pengutronix.de>
---
 drivers/soc/sifive/sifive_l2_cache.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/soc/sifive/sifive_l2_cache.c b/drivers/soc/sifive/sifive_l2_cache.c
index 1ac39c743681..f2cef133de63 100644
--- a/drivers/soc/sifive/sifive_l2_cache.c
+++ b/drivers/soc/sifive/sifive_l2_cache.c
@@ -16,6 +16,7 @@
 #include <of.h>
 #include <asm/cache.h>
 #include <asm/barrier.h>
+#include <linux/bitops.h>
 
 #define SIFIVE_L2_DIRECCFIX_LOW 0x100
 #define SIFIVE_L2_DIRECCFIX_HIGH 0x104
@@ -41,6 +42,9 @@
 
 #define SIFIVE_L2_MAX_ECCINTR 4
 
+#define MASK_NUM_WAYS   GENMASK(15, 8)
+#define NUM_WAYS_SHIFT  8
+
 #define SIFIVE_L2_FLUSH64_LINE_LEN 64
 
 static void __iomem *l2_base = NULL;
@@ -87,6 +91,21 @@ struct cache_ops sifive_l2_ops = {
 	.dma_inv_range = sifive_l2_flush64_range,
 };
 
+static int sifive_l2_enable_ways(void)
+{
+	u32 config;
+	u32 ways;
+
+	config = readl(l2_base + SIFIVE_L2_CONFIG);
+	ways = (config & MASK_NUM_WAYS) >> NUM_WAYS_SHIFT;
+
+	mb();
+	writel(ways - 1, l2_base + SIFIVE_L2_WAYENABLE);
+	mb();
+
+	return 0;
+}
+
 /* Normally, L2 should be kept coherent between SiFive CPUs and other
  * DMA masters on the SoC. If that's not the case, add it to the table
  * here, so barebox dma_map_single and co. flush and invalidate as
@@ -112,6 +131,8 @@ static int sifive_l2_probe(struct device_d *dev)
 
 	l2_base = IOMEM(iores->start);
 
+	sifive_l2_enable_ways();
+
 	dev->info = sifive_l2_config_read;
 
 	if (of_match_node(incoherent_soc_dt_ids, of_get_root_node())) {
-- 
2.29.2