Tegra194: save system suspend entry marker to TZDRAM
This patch adds support to save the system suspend entry and exit
markers to TZDRAM to help the trampoline code decide if the current
warmboot is actually an exit from System Suspend.
The Tegra194 platform handler sets the system suspend entry marker
before entering SC7 state and the trampoline flips the state back to
system resume, on exiting SC7.
Change-Id: I29d73f1693c89ebc8d19d7abb1df1e460eb5558e
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/nvidia/tegra/soc/t194/plat_trampoline.S b/plat/nvidia/tegra/soc/t194/plat_trampoline.S
index ea8cbef..33c7e6f 100644
--- a/plat/nvidia/tegra/soc/t194/plat_trampoline.S
+++ b/plat/nvidia/tegra/soc/t194/plat_trampoline.S
@@ -10,6 +10,8 @@
#include <memctrl_v2.h>
#include <tegra_def.h>
+#define TEGRA194_STATE_SYSTEM_SUSPEND 0x5C7
+#define TEGRA194_STATE_SYSTEM_RESUME 0x600D
#define TEGRA194_SMMU_CTX_SIZE 0x490
.align 4
@@ -17,17 +19,24 @@
/* CPU reset handler routine */
func tegra194_cpu_reset_handler
- /*
- * The TZRAM loses state during System Suspend. We use this
- * information to decide if the reset handler is running after a
- * System Suspend. Resume from system suspend requires restoring
- * the entire state from TZDRAM to TZRAM.
- */
- mov x0, #BL31_BASE
- ldr x0, [x0]
- cbnz x0, boot_cpu
+ /* check if we are exiting system suspend state */
+ adr x0, __tegra194_system_suspend_state
+ ldr x1, [x0]
+ mov x2, #TEGRA194_STATE_SYSTEM_SUSPEND
+ lsl x2, x2, #16
+ add x2, x2, #TEGRA194_STATE_SYSTEM_SUSPEND
+ cmp x1, x2
+ bne boot_cpu
+
+ /* set system resume state */
+ mov x1, #TEGRA194_STATE_SYSTEM_RESUME
+ lsl x1, x1, #16
+ mov x2, #TEGRA194_STATE_SYSTEM_RESUME
+ add x1, x1, x2
+ str x1, [x0]
+ dsb sy
- /* resume from system suspend */
+ /* prepare to relocate to TZSRAM */
mov x0, #BL31_BASE
adr x1, __tegra194_cpu_reset_handler_end
adr x2, __tegra194_cpu_reset_handler_data
@@ -71,6 +80,10 @@
.quad tegra_secure_entrypoint
.quad __BL31_END__ - BL31_BASE
+ .globl __tegra194_system_suspend_state
+__tegra194_system_suspend_state:
+ .quad 0
+
.align 4
__tegra194_smmu_context:
.rept TEGRA194_SMMU_CTX_SIZE
@@ -86,6 +99,7 @@
.globl tegra194_get_cpu_reset_handler_size
.globl tegra194_get_cpu_reset_handler_base
.globl tegra194_get_smmu_ctx_offset
+ .globl tegra194_set_system_suspend_entry
/* return size of the CPU reset handler */
func tegra194_get_cpu_reset_handler_size
@@ -108,3 +122,23 @@
sub x0, x0, x1
ret
endfunc tegra194_get_smmu_ctx_offset
+
+/* set system suspend state before SC7 entry */
+func tegra194_set_system_suspend_entry
+ mov x0, #TEGRA_MC_BASE
+ mov x3, #MC_SECURITY_CFG3_0
+ ldr w1, [x0, x3]
+ lsl x1, x1, #32
+ mov x3, #MC_SECURITY_CFG0_0
+ ldr w2, [x0, x3]
+ orr x3, x1, x2 /* TZDRAM base */
+ adr x0, __tegra194_system_suspend_state
+ adr x1, tegra194_cpu_reset_handler
+ sub x2, x0, x1 /* offset in TZDRAM */
+ mov x0, #TEGRA194_STATE_SYSTEM_SUSPEND
+ lsl x0, x0, #16
+ add x0, x0, #TEGRA194_STATE_SYSTEM_SUSPEND
+ str x0, [x3, x2] /* set value in TZDRAM */
+ dsb sy
+ ret
+endfunc tegra194_set_system_suspend_entry