ti: k3: drivers: Add Secure Proxy driver

Secure Proxy module manages hardware threads that are meant
for communication between the processor entities. Add support
for this here.
Signed-off-by: Andrew F. Davis <afd@ti.com>

plat/ti/k3/common/drivers/sec_proxy/sec_proxy.c

+/*
+ * Texas Instruments K3 Secure Proxy Driver
+ *   Based on Linux and U-Boot implementation
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <debug.h>
+#include <errno.h>
+#include <mmio.h>
+#include <platform_def.h>
+#include <stdlib.h>
+#include <utils.h>
+#include <utils_def.h>
+
+#include "sec_proxy.h"
+
+/* SEC PROXY RT THREAD STATUS */
+#define RT_THREAD_STATUS			(0x0)
+#define RT_THREAD_STATUS_ERROR_SHIFT		(31)
+#define RT_THREAD_STATUS_ERROR_MASK		BIT(31)
+#define RT_THREAD_STATUS_CUR_CNT_SHIFT		(0)
+#define RT_THREAD_STATUS_CUR_CNT_MASK		GENMASK(7, 0)
+
+/* SEC PROXY SCFG THREAD CTRL */
+#define SCFG_THREAD_CTRL			(0x1000)
+#define SCFG_THREAD_CTRL_DIR_SHIFT		(31)
+#define SCFG_THREAD_CTRL_DIR_MASK		BIT(31)
+
+#define SEC_PROXY_THREAD(base, x)		((base) + (0x1000 * (x)))
+#define THREAD_IS_RX				(1)
+#define THREAD_IS_TX				(0)
+
+/**
+ * struct k3_sec_proxy_desc - Description of secure proxy integration
+ * @timeout_us:		Timeout for communication (in Microseconds)
+ * @max_msg_size:	Message size in bytes
+ * @data_start_offset:	Offset of the First data register of the thread
+ * @data_end_offset:	Offset of the Last data register of the thread
+ */
+struct k3_sec_proxy_desc {
+	uint32_t timeout_us;
+	uint16_t max_msg_size;
+	uint16_t data_start_offset;
+	uint16_t data_end_offset;
+};
+
+/**
+ * struct k3_sec_proxy_thread - Description of a secure proxy Thread
+ * @id:		Thread ID
+ * @data:	Thread Data path region for target
+ * @scfg:	Secure Config Region for Thread
+ * @rt:		RealTime Region for Thread
+ */
+struct k3_sec_proxy_thread {
+	uint32_t id;
+	uintptr_t data;
+	uintptr_t scfg;
+	uintptr_t rt;
+};
+
+/**
+ * struct k3_sec_proxy_mbox - Description of a Secure Proxy Instance
+ * @desc:	Description of the SoC integration
+ * @chans:	Array for valid thread instances
+ */
+struct k3_sec_proxy_mbox {
+	const struct k3_sec_proxy_desc desc;
+	struct k3_sec_proxy_thread threads[];
+};
+
+/*
+ * Thread ID #0: DMSC notify
+ * Thread ID #1: DMSC request response
+ * Thread ID #2: DMSC request high priority
+ * Thread ID #3: DMSC request low priority
+ * Thread ID #4: DMSC notify response
+ */
+#define SP_THREAD(_x) \
+	[_x] = { \
+		.id = _x, \
+		.data = SEC_PROXY_THREAD(SEC_PROXY_DATA_BASE, _x), \
+		.scfg = SEC_PROXY_THREAD(SEC_PROXY_SCFG_BASE, _x), \
+		.rt = SEC_PROXY_THREAD(SEC_PROXY_RT_BASE, _x), \
+	}
+
+static struct k3_sec_proxy_mbox spm = {
+	.desc = {
+		.timeout_us = SEC_PROXY_TIMEOUT_US,
+		.max_msg_size = SEC_PROXY_MAX_MESSAGE_SIZE,
+		.data_start_offset = 0x4,
+		.data_end_offset = 0x3C,
+	},
+	.threads = {
+		SP_THREAD(SP_NOTIFY),
+		SP_THREAD(SP_RESPONSE),
+		SP_THREAD(SP_HIGH_PRIORITY),
+		SP_THREAD(SP_LOW_PRIORITY),
+		SP_THREAD(SP_NOTIFY_RESP),
+	},
+};
+
+/**
+ * struct sec_msg_hdr - Message header for secure messages and responses
+ * @checksum:	CRC of message for integrity checking
+ */
+union sec_msg_hdr {
+	struct {
+		uint16_t checksum;
+		uint16_t reserved;
+	} __packed;
+	uint32_t data;
+};
+
+/**
+ * k3_sec_proxy_verify_thread() - Verify thread status before
+ *				  sending/receiving data
+ * @spt: Pointer to Secure Proxy thread description
+ * @dir: Direction of the thread
+ *
+ * Return: 0 if all goes well, else appropriate error message
+ */
+static inline int k3_sec_proxy_verify_thread(struct k3_sec_proxy_thread *spt,
+					     uint32_t dir)
+{
+	/* Check for any errors already available */
+	if (mmio_read_32(spt->rt + RT_THREAD_STATUS) &
+	    RT_THREAD_STATUS_ERROR_MASK) {
+		ERROR("Thread %d is corrupted, cannot send data\n", spt->id);
+		return -EINVAL;
+	}
+
+	/* Make sure thread is configured for right direction */
+	if ((mmio_read_32(spt->scfg + SCFG_THREAD_CTRL) & SCFG_THREAD_CTRL_DIR_MASK)
+	    != (dir << SCFG_THREAD_CTRL_DIR_SHIFT)) {
+		if (dir)
+			ERROR("Trying to receive data on tx Thread %d\n",
+			      spt->id);
+		else
+			ERROR("Trying to send data on rx Thread %d\n",
+			      spt->id);
+		return -EINVAL;
+	}
+
+	/* Check the message queue before sending/receiving data */
+	uint32_t tick_start = (uint32_t)read_cntpct_el0();
+	uint32_t ticks_per_us = SYS_COUNTER_FREQ_IN_TICKS / 1000000;
+	while (!(mmio_read_32(spt->rt + RT_THREAD_STATUS) & RT_THREAD_STATUS_CUR_CNT_MASK)) {
+		VERBOSE("Waiting for thread %d to clear\n", spt->id);
+		if (((uint32_t)read_cntpct_el0() - tick_start) >
+		    (spm.desc.timeout_us * ticks_per_us)) {
+			ERROR("Timeout waiting for thread %d to clear\n", spt->id);
+			return -ETIMEDOUT;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * k3_sec_proxy_send() - Send data over a Secure Proxy thread
+ * @id: Channel Identifier
+ * @msg: Pointer to k3_sec_proxy_msg
+ *
+ * Return: 0 if all goes well, else appropriate error message
+ */
+int k3_sec_proxy_send(enum k3_sec_proxy_chan_id id, const struct k3_sec_proxy_msg *msg)
+{
+	struct k3_sec_proxy_thread *spt = &spm.threads[id];
+	union sec_msg_hdr secure_header;
+	int num_words, trail_bytes, i, ret;
+	uintptr_t data_reg;
+
+	ret = k3_sec_proxy_verify_thread(spt, THREAD_IS_TX);
+	if (ret) {
+		ERROR("Thread %d verification failed (%d)\n", spt->id, ret);
+		return ret;
+	}
+
+	/* Check the message size */
+	if (msg->len + sizeof(secure_header) > spm.desc.max_msg_size) {
+		ERROR("Thread %d message length %lu > max msg size\n",
+		      spt->id, msg->len);
+		return -EINVAL;
+	}
+
+	/* TODO: Calculate checksum */
+	secure_header.checksum = 0;
+
+	/* Send the secure header */
+	data_reg = spm.desc.data_start_offset;
+	mmio_write_32(spt->data + data_reg, secure_header.data);
+	data_reg += sizeof(uint32_t);
+
+	/* Send whole words */
+	num_words = msg->len / sizeof(uint32_t);
+	for (i = 0; i < num_words; i++) {
+		mmio_write_32(spt->data + data_reg, ((uint32_t *)msg->buf)[i]);
+		data_reg += sizeof(uint32_t);
+	}
+
+	/* Send remaining bytes */
+	trail_bytes = msg->len % sizeof(uint32_t);
+	if (trail_bytes) {
+		uint32_t data_trail = 0;
+
+		i = msg->len - trail_bytes;
+		while (trail_bytes--) {
+			data_trail <<= 8;
+			data_trail |= msg->buf[i++];
+		}
+
+		mmio_write_32(spt->data + data_reg, data_trail);
+		data_reg += sizeof(uint32_t);
+	}
+	/*
+	 * 'data_reg' indicates next register to write. If we did not already
+	 * write on tx complete reg(last reg), we must do so for transmit
+	 */
+	if (data_reg <= spm.desc.data_end_offset)
+		mmio_write_32(spt->data + spm.desc.data_end_offset, 0);
+
+	VERBOSE("Message successfully sent on thread %ud\n", id);
+
+	return 0;
+}
+
+/**
+ * k3_sec_proxy_recv() - Receive data from a Secure Proxy thread
+ * @id: Channel Identifier
+ * @msg: Pointer to k3_sec_proxy_msg
+ *
+ * Return: 0 if all goes well, else appropriate error message
+ */
+int k3_sec_proxy_recv(uint32_t id, struct k3_sec_proxy_msg *msg)
+{
+	struct k3_sec_proxy_thread *spt = &spm.threads[id];
+	union sec_msg_hdr secure_header;
+	uintptr_t data_reg;
+	int num_words, trail_bytes, i, ret;
+
+	ret = k3_sec_proxy_verify_thread(spt, THREAD_IS_RX);
+	if (ret) {
+		ERROR("Thread %d verification failed (%d)\n", spt->id, ret);
+		return ret;
+	}
+
+	/* Read secure header */
+	data_reg = spm.desc.data_start_offset;
+	secure_header.data = mmio_read_32(spt->data + data_reg);
+	data_reg += sizeof(uint32_t);
+
+	/* Read whole words */
+	num_words = msg->len / sizeof(uint32_t);
+	for (i = 0; i < num_words; i++) {
+		((uint32_t *)msg->buf)[i] = mmio_read_32(spt->data + data_reg);
+		data_reg += sizeof(uint32_t);
+	}
+
+	/* Read remaining bytes */
+	trail_bytes = msg->len % sizeof(uint32_t);
+	if (trail_bytes) {
+		uint32_t data_trail = mmio_read_32(spt->data + data_reg);
+		data_reg += sizeof(uint32_t);
+
+		i = msg->len - trail_bytes;
+		while (trail_bytes--) {
+			msg->buf[i] = data_trail & 0xff;
+			data_trail >>= 8;
+		}
+	}
+
+	/*
+	 * 'data_reg' indicates next register to read. If we did not already
+	 * read on rx complete reg(last reg), we must do so for receive
+	 */
+	if (data_reg <= spm.desc.data_end_offset)
+		mmio_read_32(spt->data + spm.desc.data_end_offset);
+
+	/* TODO: Verify checksum */
+	(void)secure_header.checksum;
+
+	VERBOSE("Message successfully received from thread %ud\n", id);
+
+	return 0;
+}

plat/ti/k3/common/drivers/sec_proxy/sec_proxy.h

+/*
+ * Texas Instruments K3 Secure Proxy Driver
+ *   Based on Linux and U-Boot implementation
+ *
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef K3_SEC_PROXY_H
+#define K3_SEC_PROXY_H
+
+#include <stdint.h>
+
+/**
+ * enum k3_sec_proxy_chan_id - Secure Proxy thread IDs
+ *
+ * These the available IDs used in k3_sec_proxy_{send,recv}()
+ */
+enum k3_sec_proxy_chan_id {
+	SP_NOTIFY = 0,
+	SP_RESPONSE,
+	SP_HIGH_PRIORITY,
+	SP_LOW_PRIORITY,
+	SP_NOTIFY_RESP,
+};
+
+/**
+ * struct k3_sec_proxy_msg - Secure proxy message structure
+ * @len: Length of data in the Buffer
+ * @buf: Buffer pointer
+ *
+ * This is the structure for data used in k3_sec_proxy_{send,recv}()
+ */
+struct k3_sec_proxy_msg {
+	size_t len;
+	uint8_t *buf;
+};
+
+/**
+ * k3_sec_proxy_send() - Send data over a Secure Proxy thread
+ * @id: Channel Identifier
+ * @msg: Pointer to k3_sec_proxy_msg
+ *
+ * Return: 0 if all goes well, else appropriate error message
+ */
+int k3_sec_proxy_send(enum k3_sec_proxy_chan_id id, const struct k3_sec_proxy_msg *msg);
+
+/**
+ * k3_sec_proxy_recv() - Receive data from a Secure Proxy thread
+ * @id: Channel Identifier
+ * @msg: Pointer to k3_sec_proxy_msg
+ *
+ * Return: 0 if all goes well, else appropriate error message
+ */
+int k3_sec_proxy_recv(enum k3_sec_proxy_chan_id id, struct k3_sec_proxy_msg *msg);
+
+#endif /* K3_SEC_PROXY_H */

plat/ti/k3/common/k3_bl31_setup.c

@@ -21,6 +21,9 @@ const mmap_region_t plat_arm_mmap[] = {
 	MAP_REGION_FLAT(K3_USART_BASE_ADDRESS, K3_USART_SIZE, MT_DEVICE | MT_RW | MT_SECURE),
 	MAP_REGION_FLAT(K3_GICD_BASE, K3_GICD_SIZE, MT_DEVICE | MT_RW | MT_SECURE),
 	MAP_REGION_FLAT(K3_GICR_BASE, K3_GICR_SIZE, MT_DEVICE | MT_RW | MT_SECURE),
+	MAP_REGION_FLAT(SEC_PROXY_RT_BASE, SEC_PROXY_RT_SIZE, MT_DEVICE | MT_RW | MT_SECURE),
+	MAP_REGION_FLAT(SEC_PROXY_SCFG_BASE, SEC_PROXY_SCFG_SIZE, MT_DEVICE | MT_RW | MT_SECURE),
+	MAP_REGION_FLAT(SEC_PROXY_DATA_BASE, SEC_PROXY_DATA_SIZE, MT_DEVICE | MT_RW | MT_SECURE),
 	{ /* sentinel */ }
 };
 

plat/ti/k3/common/plat_common.mk

@@ -36,6 +36,7 @@ PLAT_INCLUDES		+=	\
 				-I${PLAT_PATH}/include			\
 				-Iinclude/plat/arm/common/		\
 				-Iinclude/plat/arm/common/aarch64/	\
+				-I${PLAT_PATH}/common/drivers/sec_proxy	\
 
 K3_CONSOLE_SOURCES	+=	\
 				drivers/console/aarch64/console.S	\
@@ -53,6 +54,9 @@ K3_PSCI_SOURCES		+=	\
 				plat/common/plat_psci_common.c		\
 				${PLAT_PATH}/common/k3_psci.c		\
 
+K3_SEC_PROXY_SOURCES	+=	\
+				${PLAT_PATH}/common/drivers/sec_proxy/sec_proxy.c \
+
 PLAT_BL_COMMON_SOURCES	+=	\
 				plat/arm/common/arm_common.c		\
 				lib/cpus/aarch64/cortex_a53.S		\
@@ -65,3 +69,4 @@ BL31_SOURCES		+=	\
 				${PLAT_PATH}/common/k3_topology.c	\
 				${K3_GIC_SOURCES}			\
 				${K3_PSCI_SOURCES}			\
+				${K3_SEC_PROXY_SOURCES}			\

plat/ti/k3/include/platform_def.h

@@ -106,7 +106,7 @@
  * runtime memory used, choose the smallest value needed to register the
  * required regions for each BL stage.
  */
-#define MAX_MMAP_REGIONS	8
+#define MAX_MMAP_REGIONS	11
 
 /*
  * Defines the total size of the address space in bytes. For example, for a 32
@@ -193,4 +193,14 @@
 #define K3_GICR_BASE  0x01880000
 #define K3_GICR_SIZE  0x100000
 
+#define SEC_PROXY_DATA_BASE	0x32C00000
+#define SEC_PROXY_DATA_SIZE	0x80000
+#define SEC_PROXY_SCFG_BASE	0x32800000
+#define SEC_PROXY_SCFG_SIZE	0x80000
+#define SEC_PROXY_RT_BASE	0x32400000
+#define SEC_PROXY_RT_SIZE	0x80000
+
+#define SEC_PROXY_TIMEOUT_US		1000000
+#define SEC_PROXY_MAX_MESSAGE_SIZE	56
+
 #endif /* __PLATFORM_DEF_H__ */