Add TrustZone (TZC-400) driver

The TZC-400 performs security checks on transactions to memory or
peripherals. Separate regions can be created in the address space each
with individual security settings.

Limitations:
This driver does not currently support raising an interrupt on access
violation.

Change-Id: Idf8ed64b4d8d218fc9b6f9d75acdb2cd441d2449

2 files changed, 476 insertions, 0 deletions

diff --git a/drivers/arm/interconnect/tzc-400/tzc400.c b/drivers/arm/interconnect/tzc-400/tzc400.c
new file mode 100644
index 0000000..b88e34a
--- /dev/null
+++ b/drivers/arm/interconnect/tzc-400/tzc400.c
@@ -0,0 +1,265 @@
+/*
+ * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include "arch_helpers.h"
+#include "tzc400.h"
+#include "mmio.h"
+#include "debug.h"
+
+static uint32_t tzc_read_build_config(uint64_t base)
+{
+	return mmio_read_32(base + BUILD_CONFIG_OFF);
+}
+
+static uint32_t tzc_read_gate_keeper(uint64_t base)
+{
+	return mmio_read_32(base + GATE_KEEPER_OFF);
+}
+
+static void tzc_write_gate_keeper(uint64_t base, uint32_t val)
+{
+	mmio_write_32(base + GATE_KEEPER_OFF, val);
+}
+
+static void tzc_write_action(uint64_t base, enum tzc_action action)
+{
+	mmio_write_32(base + ACTION_OFF, action);
+}
+
+static void tzc_write_region_base_low(uint64_t base, uint32_t region, uint32_t val)
+{
+	mmio_write_32(base + REGION_BASE_LOW_OFF + REGION_NUM_OFF(region), val);
+}
+
+static void tzc_write_region_base_high(uint64_t base, uint32_t region, uint32_t val)
+{
+	mmio_write_32(base + REGION_BASE_HIGH_OFF + REGION_NUM_OFF(region), val);
+}
+
+static void tzc_write_region_top_low(uint64_t base, uint32_t region, uint32_t val)
+{
+	mmio_write_32(base + REGION_TOP_LOW_OFF + REGION_NUM_OFF(region), val);
+}
+
+static void tzc_write_region_top_high(uint64_t base, uint32_t region, uint32_t val)
+{
+	mmio_write_32(base + REGION_TOP_HIGH_OFF + REGION_NUM_OFF(region), val);
+}
+
+static void tzc_write_region_attributes(uint64_t base, uint32_t region, uint32_t val)
+{
+	mmio_write_32(base + REGION_ATTRIBUTES_OFF + REGION_NUM_OFF(region), val);
+}
+
+static void tzc_write_region_id_access(uint64_t base, uint32_t region, uint32_t val)
+{
+	mmio_write_32(base + REGION_ID_ACCESS_OFF + REGION_NUM_OFF(region), val);
+}
+
+static uint32_t tzc_read_component_id(uint64_t base)
+{
+	uint32_t id;
+
+	id = mmio_read_8(base + CID0_OFF);
+	id |= (mmio_read_8(base + CID1_OFF) << 8);
+	id |= (mmio_read_8(base + CID2_OFF) << 16);
+	id |= (mmio_read_8(base + CID3_OFF) << 24);
+
+	return id;
+}
+
+static uint32_t tzc_get_gate_keeper(uint64_t base, uint8_t filter)
+{
+	uint32_t tmp;
+
+	tmp = (tzc_read_gate_keeper(base) >> GATE_KEEPER_OS_SHIFT) &
+		GATE_KEEPER_OS_MASK;
+
+	return tmp >> filter;
+}
+
+/* This function is not MP safe. */
+static void tzc_set_gate_keeper(uint64_t base, uint8_t filter, uint32_t val)
+{
+	uint32_t tmp;
+
+	/* Upper half is current state. Lower half is requested state. */
+	tmp = (tzc_read_gate_keeper(base) >> GATE_KEEPER_OS_SHIFT) &
+		GATE_KEEPER_OS_MASK;
+
+	if (val)
+		tmp |=  (1 << filter);
+	else
+		tmp &= ~(1 << filter);
+
+	tzc_write_gate_keeper(base, (tmp & GATE_KEEPER_OR_MASK) <<
+			      GATE_KEEPER_OR_SHIFT);
+
+	/* Wait here until we see the change reflected in the TZC status. */
+	while (((tzc_read_gate_keeper(base) >> GATE_KEEPER_OS_SHIFT) &
+		GATE_KEEPER_OS_MASK) != tmp)
+	  ;
+}
+
+
+void tzc_init(struct tzc_instance *controller)
+{
+	uint32_t tzc_id, tzc_build;
+
+	assert(controller != NULL);
+
+	/*
+	 * We expect to see a tzc400. Check component ID. The TZC-400 TRM shows
+	 * component ID is expected to be "0xB105F00D".
+	 */
+	tzc_id = tzc_read_component_id(controller->base);
+	if (tzc_id != TZC400_COMPONENT_ID) {
+		ERROR("TZC : Wrong device ID (0x%x).\n", tzc_id);
+		panic();
+	}
+
+	/* Save values we will use later. */
+	tzc_build = tzc_read_build_config(controller->base);
+	controller->num_filters = ((tzc_build >> BUILD_CONFIG_NF_SHIFT) &
+			   BUILD_CONFIG_NF_MASK) + 1;
+	controller->addr_width  = ((tzc_build >> BUILD_CONFIG_AW_SHIFT) &
+			   BUILD_CONFIG_AW_MASK) + 1;
+	controller->num_regions = ((tzc_build >> BUILD_CONFIG_NR_SHIFT) &
+			   BUILD_CONFIG_NR_MASK) + 1;
+}
+
+
+/*
+ * `tzc_configure_region` is used to program regions into the TrustZone
+ * controller. A region can be associated with more than one filter. The
+ * associated filters are passed in as a bitmap (bit0 = filter0).
+ * NOTE:
+ * The region 0 covers the whole address space and is enabled on all filters,
+ * this cannot be changed. It is, however, possible to change some region 0
+ * permissions.
+ */
+void tzc_configure_region(const struct tzc_instance *controller,
+			  uint32_t filters,
+			  uint8_t  region,
+			  uint64_t region_base,
+			  uint64_t region_top,
+			  enum tzc_region_attributes sec_attr,
+			  uint32_t ns_device_access)
+{
+	uint64_t max_addr;
+
+	assert(controller != NULL);
+
+	/* Do range checks on filters and regions. */
+	assert(((filters >> controller->num_filters) == 0) &&
+	       (region < controller->num_regions));
+
+	/*
+	 * Do address range check based on TZC configuration. A 64bit address is
+	 * the max and expected case.
+	 */
+	max_addr = UINT64_MAX >> (64 - controller->addr_width);
+	if ((region_top > max_addr) || (region_base >= region_top))
+		assert(0);
+
+	/* region_base and (region_top + 1) must be 4KB aligned */
+	assert(((region_base | (region_top + 1)) & (4096 - 1)) == 0);
+
+	assert(sec_attr <= TZC_REGION_S_RDWR);
+
+	/*
+	 * Inputs look ok, start programming registers.
+	 * All the address registers are 32 bits wide and have a LOW and HIGH
+	 * component used to construct a up to a 64bit address.
+	 */
+	tzc_write_region_base_low(controller->base, region, (uint32_t)(region_base));
+	tzc_write_region_base_high(controller->base, region, (uint32_t)(region_base >> 32));
+
+	tzc_write_region_top_low(controller->base, region, (uint32_t)(region_top));
+	tzc_write_region_top_high(controller->base, region, (uint32_t)(region_top >> 32));
+
+	/* Assign the region to a filter and set secure attributes */
+	tzc_write_region_attributes(controller->base, region,
+		(sec_attr << REGION_ATTRIBUTES_SEC_SHIFT) | filters);
+
+	/*
+	 * Specify which non-secure devices have permission to access this
+	 * region.
+	 */
+	tzc_write_region_id_access(controller->base, region, ns_device_access);
+}
+
+
+void tzc_set_action(const struct tzc_instance *controller, enum tzc_action action)
+{
+	assert(controller != NULL);
+
+	/*
+	 * - Currently no handler is provided to trap an error via interrupt
+	 *   or exception.
+	 * - The interrupt action has not been tested.
+	 */
+	tzc_write_action(controller->base, action);
+}
+
+
+void tzc_enable_filters(const struct tzc_instance *controller)
+{
+	uint32_t state;
+	uint32_t filter;
+
+	assert(controller != NULL);
+
+	for (filter = 0; filter < controller->num_filters; filter++) {
+		state = tzc_get_gate_keeper(controller->base, filter);
+		if (state) {
+			ERROR("TZC : Filter %d Gatekeeper already enabled.\n",
+				filter);
+			panic();
+		}
+		tzc_set_gate_keeper(controller->base, filter, 1);
+	}
+}
+
+
+void tzc_disable_filters(const struct tzc_instance *controller)
+{
+	uint32_t filter;
+
+	assert(controller != NULL);
+
+	/*
+	 * We don't do the same state check as above as the Gatekeepers are
+	 * disabled after reset.
+	 */
+	for (filter = 0; filter < controller->num_filters; filter++)
+		tzc_set_gate_keeper(controller->base, filter, 0);
+}
diff --git a/drivers/arm/interconnect/tzc-400/tzc400.h b/drivers/arm/interconnect/tzc-400/tzc400.h
new file mode 100644
index 0000000..7eaafd2
--- /dev/null
+++ b/drivers/arm/interconnect/tzc-400/tzc400.h
@@ -0,0 +1,211 @@
+/*
+ * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * Neither the name of ARM nor the names of its contributors may be used
+ * to endorse or promote products derived from this software without specific
+ * prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef __TZC400_H__
+#define __TZC400_H__
+
+#include <stdint.h>
+
+#define BUILD_CONFIG_OFF	0x000
+#define ACTION_OFF		0x004
+#define GATE_KEEPER_OFF		0x008
+#define SPECULATION_CTRL_OFF	0x00c
+#define INT_STATUS		0x010
+#define INT_CLEAR		0x014
+
+#define FAIL_ADDRESS_LOW_OFF	0x020
+#define FAIL_ADDRESS_HIGH_OFF	0x024
+#define FAIL_CONTROL_OFF	0x028
+#define FAIL_ID			0x02c
+
+#define REGION_BASE_LOW_OFF	0x100
+#define REGION_BASE_HIGH_OFF	0x104
+#define REGION_TOP_LOW_OFF	0x108
+#define REGION_TOP_HIGH_OFF	0x10c
+#define REGION_ATTRIBUTES_OFF	0x110
+#define REGION_ID_ACCESS_OFF	0x114
+#define REGION_NUM_OFF(region)  (0x20 * region)
+
+/* ID Registers */
+#define PID0_OFF		0xfe0
+#define PID1_OFF		0xfe4
+#define PID2_OFF		0xfe8
+#define PID3_OFF		0xfec
+#define PID4_OFF		0xfd0
+#define PID5_OFF		0xfd4
+#define PID6_OFF		0xfd8
+#define PID7_OFF		0xfdc
+#define CID0_OFF		0xff0
+#define CID1_OFF		0xff4
+#define CID2_OFF		0xff8
+#define CID3_OFF		0xffc
+
+#define BUILD_CONFIG_NF_SHIFT	24
+#define BUILD_CONFIG_NF_MASK	0x3
+#define BUILD_CONFIG_AW_SHIFT	8
+#define BUILD_CONFIG_AW_MASK	0x3f
+#define BUILD_CONFIG_NR_SHIFT	0
+#define BUILD_CONFIG_NR_MASK	0x1f
+
+/* Not describing the case where regions 1 to 8 overlap */
+#define ACTION_RV_SHIFT		0
+#define ACTION_RV_MASK		0x3
+#define  ACTION_RV_LOWOK	0x0
+#define  ACTION_RV_LOWERR	0x1
+#define  ACTION_RV_HIGHOK	0x2
+#define  ACTION_RV_HIGHERR	0x3
+
+/*
+ * Number of gate keepers is implementation defined. But we know the max for
+ * this device is 4. Get implementation details from BUILD_CONFIG.
+ */
+#define GATE_KEEPER_OS_SHIFT	16
+#define GATE_KEEPER_OS_MASK	0xf
+#define GATE_KEEPER_OR_SHIFT	0
+#define GATE_KEEPER_OR_MASK	0xf
+
+/* Speculation is enabled by default. */
+#define SPECULATION_CTRL_WRITE_DISABLE	(1 << 1)
+#define SPECULATION_CTRL_READ_DISABLE	(1 << 0)
+
+/* Max number of filters allowed is 4. */
+#define INT_STATUS_OVERLAP_SHIFT	16
+#define INT_STATUS_OVERLAP_MASK		0xf
+#define INT_STATUS_OVERRUN_SHIFT	8
+#define INT_STATUS_OVERRUN_MASK		0xf
+#define INT_STATUS_STATUS_SHIFT		0
+#define INT_STATUS_STATUS_MASK		0xf
+
+#define INT_CLEAR_CLEAR_SHIFT		0
+#define INT_CLEAR_CLEAR_MASK		0xf
+
+#define FAIL_CONTROL_DIR_SHIFT		(1 << 24)
+#define  FAIL_CONTROL_DIR_READ		0x0
+#define  FAIL_CONTROL_DIR_WRITE		0x1
+#define FAIL_CONTROL_NS_SHIFT		(1 << 21)
+#define  FAIL_CONTROL_NS_SECURE		0x0
+#define  FAIL_CONTROL_NS_NONSECURE	0x1
+#define FAIL_CONTROL_PRIV_SHIFT		(1 << 20)
+#define  FAIL_CONTROL_PRIV_PRIV		0x0
+#define  FAIL_CONTROL_PRIV_UNPRIV	0x1
+
+/*
+ * FAIL_ID_ID_MASK depends on AID_WIDTH which is platform specific.
+ * Platform should provide the value on initialisation.
+ */
+#define FAIL_ID_VNET_SHIFT		24
+#define FAIL_ID_VNET_MASK		0xf
+#define FAIL_ID_ID_SHIFT		0
+
+/* Used along with 'tzc_region_attributes_t' below */
+#define REGION_ATTRIBUTES_SEC_SHIFT	30
+#define REGION_ATTRIBUTES_F_EN_SHIFT	0
+#define REGION_ATTRIBUTES_F_EN_MASK	0xf
+
+#define REGION_ID_ACCESS_NSAID_WR_EN_SHIFT	16
+#define REGION_ID_ACCESS_NSAID_RD_EN_SHIFT	0
+#define REGION_ID_ACCESS_NSAID_ID_MASK		0xf
+
+
+/* Macros for setting Region ID access permissions based on NSAID */
+#define TZC_REGION_ACCESS_RD(id)					\
+		((1 << (id & REGION_ID_ACCESS_NSAID_ID_MASK)) <<	\
+		 REGION_ID_ACCESS_NSAID_RD_EN_SHIFT)
+#define TZC_REGION_ACCESS_WR(id)					\
+		((1 << (id & REGION_ID_ACCESS_NSAID_ID_MASK)) <<	\
+		 REGION_ID_ACCESS_NSAID_WR_EN_SHIFT)
+#define TZC_REGION_ACCESS_RDWR(id)					\
+		(TZC_REGION_ACCESS_RD(id) | TZC_REGION_ACCESS_WR(id))
+
+/* Filters are bit mapped 0 to 3. */
+#define TZC400_COMPONENT_ID	0xb105f00d
+
+#ifndef __ASSEMBLY__
+
+/*******************************************************************************
+ * Function & variable prototypes
+ ******************************************************************************/
+
+/*
+ * What type of action is expected when an access violation occurs.
+ * The memory requested is zeroed. But we can also raise and event to
+ * let the system know it happened.
+ * We can raise an interrupt(INT) and/or cause an exception(ERR).
+ *  TZC_ACTION_NONE    - No interrupt, no Exception
+ *  TZC_ACTION_ERR     - No interrupt, raise exception -> sync external
+ *                       data abort
+ *  TZC_ACTION_INT     - Raise interrupt, no exception
+ *  TZC_ACTION_ERR_INT - Raise interrupt, raise exception -> sync
+ *                       external data abort
+ */
+enum tzc_action {
+	TZC_ACTION_NONE = 0,
+	TZC_ACTION_ERR = 1,
+	TZC_ACTION_INT = 2,
+	TZC_ACTION_ERR_INT = (TZC_ACTION_ERR | TZC_ACTION_INT)
+};
+
+/*
+ * Controls secure access to a region. If not enabled secure access is not
+ * allowed to region.
+ */
+enum tzc_region_attributes {
+	TZC_REGION_S_NONE = 0,
+	TZC_REGION_S_RD = 1,
+	TZC_REGION_S_WR = 2,
+	TZC_REGION_S_RDWR = (TZC_REGION_S_RD | TZC_REGION_S_WR)
+};
+
+/*
+ * Implementation defined values used to validate inputs later.
+ * Filters : max of 4 ; 0 to 3
+ * Regions : max of 9 ; 0 to 8
+ * Address width : Values between 32 to 64
+ */
+struct tzc_instance {
+	uint64_t base;
+	uint32_t aid_width;
+	uint8_t addr_width;
+	uint8_t num_filters;
+	uint8_t num_regions;
+};
+
+void tzc_init(struct tzc_instance *controller);
+void tzc_configure_region(const struct tzc_instance *controller, uint32_t filters,
+	uint8_t region, uint64_t region_base, uint64_t region_top,
+	enum tzc_region_attributes sec_attr, uint32_t ns_device_access);
+void tzc_enable_filters(const struct tzc_instance *controller);
+void tzc_disable_filters(const struct tzc_instance *controller);
+void tzc_set_action(const struct tzc_instance *controller,
+	enum tzc_action action);
+
+#endif /*__ASSEMBLY__*/
+
+#endif /* __TZC400__ */