Tegra186: helper functions for CPU rst handler and SMMU ctx offset

This patch adds a helper function to get the SMMU context's offset
and uses another helper function to get the CPU trampoline offset.
These helper functions are used by the System Suspend entry sequence
to save the SMMU context and CPU reset handler to TZDRAM.

Change-Id: I95e2862fe37ccad00fa48ec165c6e4024df01147
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/include/t186/tegra186_private.h

@@ -10,5 +10,6 @@
 void tegra186_cpu_reset_handler(void);
 uint64_t tegra186_get_cpu_reset_handler_base(void);
 uint64_t tegra186_get_cpu_reset_handler_size(void);
+uint64_t tegra186_get_smmu_ctx_offset(void);
 
 #endif /* TEGRA186_PRIVATE_H */

plat/nvidia/tegra/soc/t186/plat_psci_handlers.c

@@ -22,12 +22,10 @@
 #include <smmu.h>
 #include <stdbool.h>
 #include <t18x_ari.h>
+#include <tegra186_private.h>
 #include <tegra_private.h>
 
 extern void memcpy16(void *dest, const void *src, unsigned int length);
-extern void tegra186_cpu_reset_handler(void);
-extern uint64_t __tegra186_cpu_reset_handler_end,
-		__tegra186_smmu_context;
 
 /* state id mask */
 #define TEGRA186_STATE_ID_MASK		0xFU
@@ -127,8 +125,7 @@ int32_t tegra_soc_pwr_domain_suspend(const psci_power_state_t *target_state)
 
 		/* save SMMU context to TZDRAM */
 		smmu_ctx_base = params_from_bl2->tzdram_base +
-			((uintptr_t)&__tegra186_smmu_context -
-			 (uintptr_t)&tegra186_cpu_reset_handler);
+				tegra186_get_smmu_ctx_offset();
 		tegra_smmu_save_context((uintptr_t)smmu_ctx_base);
 
 		/* Prepare for system suspend */
@@ -279,8 +276,7 @@ int32_t tegra_soc_pwr_domain_power_down_wfi(const psci_power_state_t *target_sta
 		 * BL3-1 over to TZDRAM.
 		 */
 		val = params_from_bl2->tzdram_base +
-			((uintptr_t)&__tegra186_cpu_reset_handler_end -
-			 (uintptr_t)&tegra186_cpu_reset_handler);
+			tegra186_get_cpu_reset_handler_size();
 		memcpy16((void *)(uintptr_t)val, (void *)(uintptr_t)BL31_BASE,
 			 (uintptr_t)&__BL31_END__ - (uintptr_t)BL31_BASE);
 	}

plat/nvidia/tegra/soc/t186/plat_trampoline.S

@@ -69,6 +69,8 @@ endfunc tegra186_cpu_reset_handler
 __tegra186_cpu_reset_handler_data:
 	.quad	tegra_secure_entrypoint
 	.quad	__BL31_END__ - BL31_BASE
+
+	.align 4
 	.globl	__tegra186_smmu_context
 __tegra186_smmu_context:
 	.rept	TEGRA186_SMMU_CTX_SIZE
@@ -83,6 +85,7 @@ __tegra186_cpu_reset_handler_end:
 
 	.globl tegra186_get_cpu_reset_handler_size
 	.globl tegra186_get_cpu_reset_handler_base
+	.globl tegra186_get_smmu_ctx_offset
 
 /* return size of the CPU reset handler */
 func tegra186_get_cpu_reset_handler_size
@@ -97,3 +100,11 @@ func tegra186_get_cpu_reset_handler_base
 	adr	x0, tegra186_cpu_reset_handler
 	ret
 endfunc tegra186_get_cpu_reset_handler_base
+
+/* return the size of the SMMU context */
+func tegra186_get_smmu_ctx_offset
+	adr	x0, __tegra186_smmu_context
+	adr	x1, tegra186_cpu_reset_handler
+	sub	x0, x0, x1
+	ret
+endfunc tegra186_get_smmu_ctx_offset