Tegra186: save/restore BL31 context to/from TZDRAM
This patch adds support to save the BL31 state to the TZDRAM
before entering system suspend. The TZRAM loses state during
system suspend and so we need to copy the entire BL31 code to
TZDRAM before entering the state.
In order to restore the state on exiting system suspend, a new
CPU reset handler is implemented which gets copied to TZDRAM
during boot. TO keep things simple we use this same reset handler
for booting secondary CPUs too.
Change-Id: I770f799c255d22279b5cdb9b4d587d3a4c54fad7
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/nvidia/tegra/soc/t186/plat_secondary.c b/plat/nvidia/tegra/soc/t186/plat_secondary.c
index df80289..406c1e0 100644
--- a/plat/nvidia/tegra/soc/t186/plat_secondary.c
+++ b/plat/nvidia/tegra/soc/t186/plat_secondary.c
@@ -28,10 +28,13 @@
* POSSIBILITY OF SUCH DAMAGE.
*/
+#include <arch_helpers.h>
#include <debug.h>
#include <mce.h>
#include <mmio.h>
+#include <string.h>
#include <tegra_def.h>
+#include <tegra_private.h>
#define MISCREG_CPU_RESET_VECTOR 0x2000
#define MISCREG_AA64_RST_LOW 0x2004
@@ -42,7 +45,8 @@
#define CPU_RESET_MODE_AA64 1
-extern void tegra_secure_entrypoint(void);
+extern uint64_t tegra_bl31_phys_base;
+extern uint64_t __tegra186_cpu_reset_handler_end;
/*******************************************************************************
* Setup secondary CPU vectors
@@ -50,12 +54,31 @@
void plat_secondary_setup(void)
{
uint32_t addr_low, addr_high;
- uint64_t reset_addr = (uint64_t)tegra_secure_entrypoint;
+ plat_params_from_bl2_t *params_from_bl2 = bl31_get_plat_params();
+ uint64_t cpu_reset_handler_base;
INFO("Setting up secondary CPU boot\n");
- addr_low = (uint32_t)reset_addr | CPU_RESET_MODE_AA64;
- addr_high = (uint32_t)((reset_addr >> 32) & 0x7ff);
+ if ((tegra_bl31_phys_base >= TEGRA_TZRAM_BASE) &&
+ (tegra_bl31_phys_base <= (TEGRA_TZRAM_BASE + TEGRA_TZRAM_SIZE))) {
+
+ /*
+ * The BL31 code resides in the TZSRAM which loses state
+ * when we enter System Suspend. Copy the wakeup trampoline
+ * code to TZDRAM to help us exit from System Suspend.
+ */
+ cpu_reset_handler_base = params_from_bl2->tzdram_base;
+ memcpy16((void *)((uintptr_t)cpu_reset_handler_base),
+ (void *)(uintptr_t)tegra186_cpu_reset_handler,
+ (uintptr_t)&__tegra186_cpu_reset_handler_end -
+ (uintptr_t)tegra186_cpu_reset_handler);
+
+ } else {
+ cpu_reset_handler_base = (uintptr_t)tegra_secure_entrypoint;
+ }
+
+ addr_low = (uint32_t)cpu_reset_handler_base | CPU_RESET_MODE_AA64;
+ addr_high = (uint32_t)((cpu_reset_handler_base >> 32) & 0x7ff);
/* write lower 32 bits first, then the upper 11 bits */
mmio_write_32(TEGRA_MISC_BASE + MISCREG_AA64_RST_LOW, addr_low);