Tegra: enable ECC/Parity protection for Cortex-A57 CPUs

This patch enables L2 ECC and Parity Protection for ARM Cortex-A57 CPUs
for Tegra SoCs.

Change-Id: I038fcd529991d0201a4951ce2730ab71b1c980f9
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

docs/plat/nvidia-tegra.md

@@ -84,3 +84,10 @@ The PSCI implementation expects each platform to expose the 'power state'
 parameter to be used during the 'SYSTEM SUSPEND' call. The state-id field
 is implementation defined on Tegra SoCs and is preferably defined by
 tegra_def.h.
+
+Tegra configs
+=============
+
+* 'tegra_enable_l2_ecc_parity_prot': This flag enables the L2 ECC and Parity
+   Protection bit, for ARM Cortex-A57 CPUs, during CPU boot. This flag will
+   be enabled by Tegrs SoCs during 'Cluster power up' or 'System Suspend' exit.

include/lib/cpus/aarch64/cortex_a57.h

@@ -87,6 +87,8 @@
 #define L2_DATA_RAM_LATENCY_3_CYCLES	0x2
 #define L2_TAG_RAM_LATENCY_3_CYCLES	0x2
 
+#define L2_ECC_PARITY_PROTECTION_BIT	(1 << 21)
+
 /*******************************************************************************
  * L2 Extended Control register specific definitions.
  ******************************************************************************/

plat/nvidia/tegra/common/aarch64/tegra_helpers.S

@@ -68,6 +68,7 @@
 	.globl	ns_image_entrypoint
 	.globl	tegra_bl31_phys_base
 	.globl	tegra_console_base
+	.globl	tegra_enable_l2_ecc_parity_prot
 
 	/* ---------------------
 	 * Common CPU init code
@@ -76,8 +77,8 @@
 .macro	cpu_init_common
 
 	/* ------------------------------------------------
-	 * We enable procesor retention and L2/CPUECTLR NS
+	 * We enable procesor retention, L2/CPUECTLR NS
-	 * access for A57 CPUs only.
+	 * access and ECC/Parity protection for A57 CPUs
 	 * ------------------------------------------------
 	 */
 	mrs	x0, midr_el1
@@ -90,7 +91,7 @@
 	/* ---------------------------
 	 * Enable processor retention
 	 * ---------------------------
-	*/
+	 */
 	mrs	x0, L2ECTLR_EL1
 	mov	x1, #RETENTION_ENTRY_TICKS_512 << L2ECTLR_RET_CTRL_SHIFT
 	bic	x0, x0, #L2ECTLR_RET_CTRL_MASK
@@ -108,12 +109,26 @@
 	/* -------------------------------------------------------
 	 * Enable L2 and CPU ECTLR RW access from non-secure world
 	 * -------------------------------------------------------
-	*/
+	 */
 	mov	x0, #ACTLR_EL3_ENABLE_ALL_ACCESS
 	msr	actlr_el3, x0
 	msr	actlr_el2, x0
 	isb
 
+	/* -------------------------------------------------------
+	 * Enable L2 ECC and Parity Protection
+	 * -------------------------------------------------------
+	 */
+	adr	x0, tegra_enable_l2_ecc_parity_prot
+	ldr	x0, [x0]
+	cbz	x0, 1f
+	mrs	x0, L2CTLR_EL1
+	and	x1, x0, #L2_ECC_PARITY_PROTECTION_BIT
+	cbnz	x1, 1f
+	orr	x0, x0, #L2_ECC_PARITY_PROTECTION_BIT
+	msr	L2CTLR_EL1, x0
+	isb
+
 	/* --------------------------------
 	 * Enable the cycle count register
 	 * --------------------------------
@@ -454,3 +469,10 @@ tegra_bl31_phys_base:
 	 */
 tegra_console_base:
 	.quad	0
+
+	/* --------------------------------------------------
+	 * Enable L2 ECC and Parity Protection
+	 * --------------------------------------------------
+	 */
+tegra_enable_l2_ecc_parity_prot:
+	.quad	0