fsl_sec_mon: Add driver for Security Monitor block of Freescale

The Security Monitor is the SOC’s central reporting point for
security-relevant events such as the success or failure of boot
software validation and the detection of potential security compromises.

The API's for transition of Security states have been added
which will be used in case of SECURE BOOT.

Signed-off-by: Ruchika Gupta <ruchika.gupta@freescale.com>
Signed-off-by: Gaurav Rana <gaurav.rana@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>

drivers/misc/Kconfig

@@ -53,3 +53,11 @@ config DM_CROS_EC
 	  but otherwise makes few changes. Since cros_ec also supports
 	  LPC (which doesn't support driver model yet), a full
 	  conversion is not yet possible.
+
+config CONFIG_FSL_SEC_MON
+	bool "Enable FSL SEC_MON Driver"
+	help
+	  Freescale Security Monitor block is responsible for monitoring
+	  system states.
+	  Security Monitor can be transitioned on any security failures,
+	  like software violations or hardware security violations.

drivers/misc/Makefile

@@ -28,3 +28,4 @@ obj-$(CONFIG_SMSC_LPC47M) += smsc_lpc47m.o
 obj-$(CONFIG_STATUS_LED) += status_led.o
 obj-$(CONFIG_TWL4030_LED) += twl4030_led.o
 obj-$(CONFIG_FSL_IFC) += fsl_ifc.o
+obj-$(CONFIG_FSL_SEC_MON) += fsl_sec_mon.o

drivers/misc/fsl_sec_mon.c

@@ -0,0 +1,146 @@
+/*
+ * Copyright 2015 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <fsl_sec_mon.h>
+
+int change_sec_mon_state(u32 initial_state, u32 final_state)
+{
+	struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
+						(CONFIG_SYS_SEC_MON_ADDR);
+	u32 sts = sec_mon_in32(&sec_mon_regs->hp_stat);
+	int timeout = 10;
+
+	if ((sts & HPSR_SSM_ST_MASK) != initial_state)
+		return -1;
+
+	if (initial_state == HPSR_SSM_ST_TRUST) {
+		switch (final_state) {
+		case HPSR_SSM_ST_NON_SECURE:
+			printf("SEC_MON state transitioning to Soft Fail.\n");
+			sec_mon_setbits32(&sec_mon_regs->hp_com, HPCOMR_SW_SV);
+
+			/*
+			 * poll till SEC_MON is in
+			 * Soft Fail state
+			 */
+			while (((sts & HPSR_SSM_ST_MASK) !=
+				HPSR_SSM_ST_SOFT_FAIL)) {
+				while (timeout) {
+					sts = sec_mon_in32
+						(&sec_mon_regs->hp_stat);
+
+					if ((sts & HPSR_SSM_ST_MASK) ==
+						HPSR_SSM_ST_SOFT_FAIL)
+						break;
+
+					udelay(10);
+					timeout--;
+				}
+			}
+
+			if (timeout == 0) {
+				printf("SEC_MON state transition timeout.\n");
+				return -1;
+			}
+
+			timeout = 10;
+
+			printf("SEC_MON state transitioning to Non Secure.\n");
+			sec_mon_setbits32(&sec_mon_regs->hp_com, HPCOMR_SSM_ST);
+
+			/*
+			 * poll till SEC_MON is in
+			 * Non Secure state
+			 */
+			while (((sts & HPSR_SSM_ST_MASK) !=
+				HPSR_SSM_ST_NON_SECURE)) {
+				while (timeout) {
+					sts = sec_mon_in32
+						(&sec_mon_regs->hp_stat);
+
+					if ((sts & HPSR_SSM_ST_MASK) ==
+						HPSR_SSM_ST_NON_SECURE)
+						break;
+
+					udelay(10);
+					timeout--;
+				}
+			}
+
+			if (timeout == 0) {
+				printf("SEC_MON state transition timeout.\n");
+				return -1;
+			}
+			break;
+		case HPSR_SSM_ST_SOFT_FAIL:
+			printf("SEC_MON state transitioning to Soft Fail.\n");
+			sec_mon_setbits32(&sec_mon_regs->hp_com, HPCOMR_SW_FSV);
+
+			/*
+			 * polling loop till SEC_MON is in
+			 * Soft Fail state
+			 */
+			while (((sts & HPSR_SSM_ST_MASK) !=
+				HPSR_SSM_ST_SOFT_FAIL)) {
+				while (timeout) {
+					sts = sec_mon_in32
+						(&sec_mon_regs->hp_stat);
+
+					if ((sts & HPSR_SSM_ST_MASK) ==
+						HPSR_SSM_ST_SOFT_FAIL)
+						break;
+
+					udelay(10);
+					timeout--;
+				}
+			}
+
+			if (timeout == 0) {
+				printf("SEC_MON state transition timeout.\n");
+				return -1;
+			}
+			break;
+		default:
+			return -1;
+		}
+	} else if (initial_state == HPSR_SSM_ST_NON_SECURE) {
+		switch (final_state) {
+		case HPSR_SSM_ST_SOFT_FAIL:
+			printf("SEC_MON state transitioning to Soft Fail.\n");
+			sec_mon_setbits32(&sec_mon_regs->hp_com, HPCOMR_SW_FSV);
+
+			/*
+			 * polling loop till SEC_MON is in
+			 * Soft Fail state
+			 */
+			while (((sts & HPSR_SSM_ST_MASK) !=
+				HPSR_SSM_ST_SOFT_FAIL)) {
+				while (timeout) {
+					sts = sec_mon_in32
+						(&sec_mon_regs->hp_stat);
+
+					if ((sts & HPSR_SSM_ST_MASK) ==
+						HPSR_SSM_ST_SOFT_FAIL)
+						break;
+
+					udelay(10);
+					timeout--;
+				}
+			}
+
+			if (timeout == 0) {
+				printf("SEC_MON state transition timeout.\n");
+				return -1;
+			}
+			break;
+		default:
+			return -1;
+		}
+	}
+
+	return 0;
+}

include/fsl_sec_mon.h

@@ -0,0 +1,58 @@
+/*
+ * Common internal memory map for some Freescale SoCs
+ *
+ * Copyright 2015 Freescale Semiconductor, Inc.
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __FSL_SEC_MON_H
+#define __FSL_SEC_MON_H
+
+#include <common.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_SYS_FSL_SEC_MON_LE
+#define sec_mon_in32(a)       in_le32(a)
+#define sec_mon_out32(a, v)   out_le32(a, v)
+#define sec_mon_in16(a)       in_le16(a)
+#define sec_mon_clrbits32     clrbits_le32
+#define sec_mon_setbits32     setbits_le32
+#elif defined(CONFIG_SYS_FSL_SEC_MON_BE)
+#define sec_mon_in32(a)       in_be32(a)
+#define sec_mon_out32(a, v)   out_be32(a, v)
+#define sec_mon_in16(a)       in_be16(a)
+#define sec_mon_clrbits32     clrbits_be32
+#define sec_mon_setbits32     setbits_be32
+#else
+#error Neither CONFIG_SYS_FSL_SEC_MON_LE nor CONFIG_SYS_FSL_SEC_MON_BE defined
+#endif
+
+struct ccsr_sec_mon_regs {
+	u8 reserved0[0x04];
+	u32 hp_com;	/* 0x04 SEC_MON_HP Command Register */
+	u8 reserved2[0x0c];
+	u32 hp_stat;	/* 0x08 SEC_MON_HP Status Register */
+};
+
+#define HPCOMR_SW_SV 0x100		/* Security Violation bit */
+#define HPCOMR_SW_FSV 0x200		/* Fatal Security Violation bit */
+#define HPCOMR_SSM_ST 0x1		/* SSM_ST field in SEC_MON command */
+#define HPSR_SSM_ST_CHECK	0x900	/* SEC_MON is in check state */
+#define HPSR_SSM_ST_NON_SECURE	0xb00	/* SEC_MON is in non secure state */
+#define HPSR_SSM_ST_TRUST	0xd00	/* SEC_MON is in trusted state */
+#define HPSR_SSM_ST_SOFT_FAIL	0x300	/* SEC_MON is in soft fail state */
+#define HPSR_SSM_ST_MASK	0xf00	/* Mask for SSM_ST field */
+
+/*
+ * SEC_MON read. This specifies the possible reads
+ * from the SEC_MON
+ */
+enum {
+	SEC_MON_SSM_ST,
+	SEC_MON_SW_FSV,
+	SEC_MON_SW_SV,
+};
+
+int change_sec_mon_state(uint32_t initial_state, uint32_t final_state);
+
+#endif /* __FSL_SEC_MON_H */