1 files changed, 136 insertions, 0 deletions
diff --git a/arch/arm/mach-stm32mp/tzc400.c b/arch/arm/mach-stm32mp/tzc400.c
new file mode 100644
index 0000000..cdc4a40
--- /dev/null
+++ b/arch/arm/mach-stm32mp/tzc400.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Simple API for configuring TrustZone memory restrictions for TZC400
+ */
+
+#define LOG_CATEGORY LOGC_ARCH
+
+#include <linux/iopoll.h>
+#include <mach/tzc.h>
+
+#define TZC_TIMEOUT_US		100
+
+#define TZC_BUILD_CONFIG	0x00
+#define TZC_ACTION		0x04
+#define TZC_ACTION_NONE		0
+#define TZC_ACTION_ERR		1
+#define TZC_ACTION_INT		2
+#define TZC_ACTION_INT_ERR	3
+#define TZC_GATE_KEEPER		0x08
+
+#define TZC_REGION0_OFFSET	0x100
+#define TZC_REGION_CFG_SIZE	0x20
+#define TZC_REGION1_OFFSET	0x120
+#define TZC_REGION_BASE		0x00
+#define TZC_REGION_TOP		0x08
+#define TZC_REGION_ATTRIBUTE	0x10
+#define TZC_REGION_ACCESS	0x14
+
+static uint32_t tzc_read(uintptr_t tzc, size_t reg)
+{
+	return readl(tzc + reg);
+}
+
+static void tzc_write(uintptr_t tzc, size_t reg, uint32_t val)
+{
+	writel(val, tzc + reg);
+}
+
+static uint16_t tzc_config_get_active_filters(const struct tzc_region *cfg)
+{
+	uint16_t active_filters = 0;
+
+	for ( ; cfg->top != 0; cfg++)
+		active_filters |= cfg->filters_mask;
+
+	return active_filters;
+}
+
+int tzc_configure(uintptr_t tzc, const struct tzc_region *cfg)
+{
+	uintptr_t region = tzc + TZC_REGION1_OFFSET;
+	uint32_t nsid, attr_reg, active_filters;
+	int ret;
+
+	active_filters = tzc_config_get_active_filters(cfg);
+	if (active_filters == 0)
+		return -EINVAL;
+
+	ret = tzc_disable_filters(tzc, active_filters);
+	if (ret < 0)
+		return ret;
+
+	for ( ; cfg->top != 0; cfg++, region += TZC_REGION_CFG_SIZE) {
+		attr_reg = (cfg->sec_mode & 0x03) << 30;
+		attr_reg |= (cfg->filters_mask & 0x03) << 0;
+		nsid = cfg->nsec_id & 0xffff;
+		nsid |= nsid << 16;
+
+		tzc_write(region, TZC_REGION_BASE, cfg->base);
+		tzc_write(region, TZC_REGION_TOP, cfg->top);
+		tzc_write(region, TZC_REGION_ACCESS, nsid);
+		tzc_write(region, TZC_REGION_ATTRIBUTE, attr_reg);
+	}
+
+	tzc_write(tzc, TZC_ACTION, TZC_ACTION_ERR);
+	return tzc_enable_filters(tzc, active_filters);
+}
+
+int tzc_disable_filters(uintptr_t tzc, uint16_t filters_mask)
+{
+	uint32_t gate = tzc_read(tzc, TZC_GATE_KEEPER);
+	uint32_t filter_status = filters_mask << 16;
+
+	gate &= ~filters_mask;
+	tzc_write(tzc, TZC_GATE_KEEPER, gate);
+
+	return readl_poll_timeout(tzc + TZC_GATE_KEEPER, gate,
+				 (gate & filter_status) == 0, TZC_TIMEOUT_US);
+}
+
+int tzc_enable_filters(uintptr_t tzc, uint16_t filters_mask)
+{
+	uint32_t gate = tzc_read(tzc, TZC_GATE_KEEPER);
+	uint32_t filter_status = filters_mask << 16;
+
+	gate |= filters_mask;
+	tzc_write(tzc, TZC_GATE_KEEPER, gate);
+
+	return readl_poll_timeout(tzc + TZC_GATE_KEEPER, gate,
+				 (gate & filter_status) == filter_status,
+				 TZC_TIMEOUT_US);
+}
+
+static const char *sec_access_str_from_attr(uint32_t attr)
+{
+	const char *const sec_mode[] = { "none", "RO  ", "WO  ", "RW  " };
+
+	return sec_mode[(attr >> 30) & 0x03];
+}
+
+void tzc_dump_config(uintptr_t tzc)
+{
+	uint32_t build_config, base, top, attr, nsaid;
+	int num_regions, i;
+	uintptr_t region;
+
+	build_config = tzc_read(tzc, TZC_BUILD_CONFIG);
+	num_regions = ((build_config >> 0) & 0x1f) + 1;
+
+	for (i = 0; i < num_regions; i++) {
+		region = tzc + TZC_REGION0_OFFSET + i * TZC_REGION_CFG_SIZE;
+
+		base = tzc_read(region, TZC_REGION_BASE);
+		top = tzc_read(region, TZC_REGION_TOP);
+		attr = tzc_read(region, TZC_REGION_ATTRIBUTE);
+		nsaid = tzc_read(region, TZC_REGION_ACCESS);
+
+		if (attr == 0 && nsaid == 0)
+			continue;
+
+		log_info("TZC region %u: %08x->%08x - filters 0x%x\n",
+			 i, base, top, (attr >> 0) & 0xf);
+		log_info("\t Secure access %s NSAID %08x\n",
+			 sec_access_str_from_attr(attr), nsaid);
+	}
+}