[PATCH v4 1/8] ARM: trusted_foundations: Implement L2 cache initialization callback

[Dmitry Osipenko]

Implement L2 cache initialization firmware callback that should be
invoked early during boot in order to set up the required outer cache
driver's callbacks.

Partially based on work done by MichaÅ MirosÅaw [1].

[1] https://www.spinics.net/lists/arm-kernel/msg594765.html

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
 arch/arm/firmware/trusted_foundations.c | 46 +++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/arch/arm/firmware/trusted_foundations.c b/arch/arm/firmware/trusted_foundations.c
index 689e6565abfc..3bf61a5933b9 100644
--- a/arch/arm/firmware/trusted_foundations.c
+++ b/arch/arm/firmware/trusted_foundations.c
@@ -18,8 +18,15 @@
 #include <linux/init.h>
 #include <linux/of.h>
 #include <asm/firmware.h>
+#include <asm/hardware/cache-l2x0.h>
+#include <asm/outercache.h>
 #include <asm/trusted_foundations.h>
 
+#define TF_CACHE_MAINT		0xfffff100
+
+#define TF_CACHE_ENABLE		1
+#define TF_CACHE_DISABLE	2
+
 #define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200
 
 #define TF_CPU_PM		0xfffffffc
@@ -67,9 +74,48 @@ static int tf_prepare_idle(void)
 	return 0;
 }
 
+#ifdef CONFIG_CACHE_L2X0
+static void tf_cache_write_sec(unsigned long val, unsigned int reg)
+{
+	static u32 l2x0_way_mask = 0xff;
+	static u32 l2x0_aux_ctrl = 0;
+
+	switch (reg) {
+	case L2X0_AUX_CTRL:
+		l2x0_aux_ctrl = val;
+
+		if (l2x0_aux_ctrl & BIT(16))
+			l2x0_way_mask = 0xffff;
+		break;
+
+	case L2X0_CTRL:
+		if (val == L2X0_CTRL_EN)
+			tf_generic_smc(TF_CACHE_MAINT, TF_CACHE_ENABLE,
+				       l2x0_aux_ctrl);
+		else
+			tf_generic_smc(TF_CACHE_MAINT, TF_CACHE_DISABLE,
+				       l2x0_way_mask);
+		break;
+
+	default:
+		break;
+	}
+}
+
+static int tf_init_cache(void)
+{
+	outer_cache.write_sec = tf_cache_write_sec;
+
+	return 0;
+}
+#endif /* CONFIG_CACHE_L2X0 */
+
 static const struct firmware_ops trusted_foundations_ops = {
 	.set_cpu_boot_addr = tf_set_cpu_boot_addr,
 	.prepare_idle = tf_prepare_idle,
+#ifdef CONFIG_CACHE_L2X0
+	.l2x0_init = tf_init_cache,
+#endif
 };
 
 void register_trusted_foundations(struct trusted_foundations_platform_data *pd)
-- 
2.20.1