fsl_sec_mon: Update driver for Security Monitor

Update the API's for transition of Security Monitor states. Instead
of providing both initial and final states for transition, just
provide final state for transition as Security Monitor driver will
take care of it internally.

Signed-off-by: Sumit Garg <sumit.garg@nxp.com>
[York Sun: Reformatted commit message slightly]
Reviewed-by: York Sun <york.sun@nxp.com>

1 files changed, 129 insertions, 111 deletions

diff --git a/drivers/misc/fsl_sec_mon.c b/drivers/misc/fsl_sec_mon.c
index d482a7d..415232e 100644
--- a/drivers/misc/fsl_sec_mon.c
+++ b/drivers/misc/fsl_sec_mon.c
@@ -7,140 +7,158 @@
 #include <common.h>
 #include <fsl_sec_mon.h>
 
-int change_sec_mon_state(u32 initial_state, u32 final_state)
+static u32 get_sec_mon_state(void)
 {
 	struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
 						(CONFIG_SYS_SEC_MON_ADDR);
-	u32 sts = sec_mon_in32(&sec_mon_regs->hp_stat);
+	return sec_mon_in32(&sec_mon_regs->hp_stat) & HPSR_SSM_ST_MASK;
+}
+
+static int set_sec_mon_state_non_sec(void)
+{
+	u32 sts;
 	int timeout = 10;
+	struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
+						(CONFIG_SYS_SEC_MON_ADDR);
 
-	if ((sts & HPSR_SSM_ST_MASK) != initial_state)
-		return -1;
+	sts = get_sec_mon_state();
 
-	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--;
-				}
-			}
+	switch (sts) {
+	/*
+	 * If initial state is check or Non-Secure, then set the Software
+	 * Security Violation Bit and transition to Non-Secure State.
+	 */
+	case HPSR_SSM_ST_CHECK:
+		printf("SEC_MON state transitioning to Non Secure.\n");
+		sec_mon_setbits32(&sec_mon_regs->hp_com, HPCOMR_SW_SV);
 
-			if (timeout == 0) {
-				printf("SEC_MON state transition timeout.\n");
-				return -1;
-			}
+		/* polling loop till SEC_MON is in Non Secure state */
+		while (timeout) {
+			sts = get_sec_mon_state();
+
+			if ((sts & HPSR_SSM_ST_MASK) ==
+				HPSR_SSM_ST_NON_SECURE)
+				break;
+
+			udelay(10);
+			timeout--;
+		}
 
-			timeout = 10;
+		if (timeout == 0) {
+			printf("SEC_MON state transition timeout.\n");
+			return -1;
+		}
+		break;
+
+	/*
+	 * If initial state is Trusted, Secure or Soft-Fail, then first set
+	 * the Software Security Violation Bit and transition to Soft-Fail
+	 * State.
+	 */
+	case HPSR_SSM_ST_TRUST:
+	case HPSR_SSM_ST_SECURE:
+	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_SV);
+
+		/* polling loop till SEC_MON is in Soft-Fail state */
+		while (timeout) {
+			sts = get_sec_mon_state();
+
+			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;
 
+		/*
+		 * If SSM Soft Fail to Non-Secure State Transition
+		 * disable is not set, then set SSM_ST bit and
+		 * transition to Non-Secure State.
+		 */
+		if ((sec_mon_in32(&sec_mon_regs->hp_com) &
+			HPCOMR_SSM_SFNS_DIS) == 0) {
 			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--;
-				}
-			}
+			/* polling loop till SEC_MON is in Non Secure*/
+			while (timeout) {
+				sts = get_sec_mon_state();
 
-			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 ((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;
-		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--;
-				}
-			}
+		break;
+	default:
+		printf("SEC_MON already in Non Secure state.\n");
+		return 0;
+	}
+	return 0;
+}
 
-			if (timeout == 0) {
-				printf("SEC_MON state transition timeout.\n");
-				return -1;
-			}
+static int set_sec_mon_state_soft_fail(void)
+{
+	u32 sts;
+	int timeout = 10;
+	struct ccsr_sec_mon_regs *sec_mon_regs = (void *)
+						(CONFIG_SYS_SEC_MON_ADDR);
+
+	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 (timeout) {
+		sts = get_sec_mon_state();
+
+		if ((sts & HPSR_SSM_ST_MASK) ==
+			HPSR_SSM_ST_SOFT_FAIL)
 			break;
-		default:
-			return -1;
-		}
+
+		udelay(10);
+		timeout--;
 	}
 
+	if (timeout == 0) {
+		printf("SEC_MON state transition timeout.\n");
+		return -1;
+	}
 	return 0;
 }
+
+int set_sec_mon_state(u32 state)
+{
+	int ret = -1;
+
+	switch (state) {
+	case HPSR_SSM_ST_NON_SECURE:
+		ret = set_sec_mon_state_non_sec();
+		break;
+	case HPSR_SSM_ST_SOFT_FAIL:
+		ret = set_sec_mon_state_soft_fail();
+		break;
+	default:
+		printf("SEC_MON state transition not supported.\n");
+		return 0;
+	}
+
+	return ret;
+}