commit e6b871e01e4cec00e100906497d8c666436178d5
author York Sun <york.sun@nxp.com> Mon May 15 08:51:59 2017 -0700
committer York Sun <york.sun@nxp.com> Thu Jun 01 19:57:24 2017 -0700
tree 5e13e5deea8e8d73302f4731e1ea1d6d42ef3236
parent 1afa9009c217dae2c67ad4764aabd06ea0223a7e

armv8: layerscape: Make U-Boot EL2 safe

When U-Boot boots from EL2, skip some lowlevel init code requiring
EL3, including CCI-400/CCN-504, trust zone, GIC, etc. These
initialization tasks are carried out before U-Boot runs. This applies
to the RAM version image used for SPL boot if PPA is loaded first.

Signed-off-by: York Sun <york.sun@nxp.com>

arch/arm/cpu/armv8/fsl-layerscape/soc.c

diff --git a/arch/arm/cpu/armv8/fsl-layerscape/soc.c b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
index 76e3af0..0943e83 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
@@ -288,6 +288,10 @@
 	struct ccsr_cci400 __iomem *cci = (void *)CONFIG_SYS_CCI400_ADDR;
 	struct ccsr_ddr __iomem *ddr = (void *)CONFIG_SYS_FSL_DDR_ADDR;
 
+	/* Skip if running at lower exception level */
+	if (current_el() < 3)
+		return;
+
 	/* disables propagation of barrier transactions to DDRC from CCI400 */
 	out_le32(&cci->ctrl_ord, CCI400_CTRLORD_TERM_BARRIER);
 
@@ -304,6 +308,10 @@
 	struct ccsr_ddr __iomem *ddr = (void *)CONFIG_SYS_FSL_DDR_ADDR;
 	u32 tmp;
 
+	/* Skip if running at lower exception level */
+	if (current_el() < 3)
+		return;
+
 	/* enable propagation of barrier transactions to DDRC from CCI400 */
 	out_le32(&cci->ctrl_ord, CCI400_CTRLORD_EN_BARRIER);
 
@@ -455,8 +463,10 @@
 	 * Enable snoop requests and DVM message requests for
 	 * Slave insterface S4 (A53 core cluster)
 	 */
-	out_le32(&cci->slave[4].snoop_ctrl,
-		 CCI400_DVM_MESSAGE_REQ_EN | CCI400_SNOOP_REQ_EN);
+	if (current_el() == 3) {
+		out_le32(&cci->slave[4].snoop_ctrl,
+			 CCI400_DVM_MESSAGE_REQ_EN | CCI400_SNOOP_REQ_EN);
+	}
 
 	/* Erratum */
 	erratum_a008850_early(); /* part 1 of 2 */