elfloader: Add generic-timer driver

This driver just sets CNTVOFF_El2 to 0 if possible.
This can only be done if the elfloader is in hyp-mode, otherwise nothing
happens.

Signed-off-by: Kent McLeod <kent@kry10.com>

elfloader-tool/CMakeLists.txt

@@ -163,6 +163,7 @@ file(
         src/drivers/*.c
         src/drivers/smp/*.c
         src/drivers/uart/*.c
+        src/drivers/timer/*.c
         src/utils/*.c
         src/arch-${KernelArch}/*.c
         src/arch-${KernelArch}/*.S

elfloader-tool/include/drivers/common.h

@@ -26,6 +26,7 @@ enum driver_type {
     DRIVER_INVALID = 0,
     DRIVER_SMP,
     DRIVER_UART,
+    DRIVER_TIMER,
     DRIVER_MAX
 };
 

elfloader-tool/src/arch-arm/smp_boot.c

@@ -43,6 +43,9 @@ void non_boot_main(void)
     /* Initialise any platform-specific per-core state */
     non_boot_init();
 
+    /* Reset the virtual offset for the platform timer to 0 if it exists */
+    generic_timer_non_boot_init();
+
 #ifndef CONFIG_ARM_HYPERVISOR_SUPPORT
     if (is_hyp_mode()) {
         extern void leave_hyp(void);

elfloader-tool/src/drivers/timer/generic_timer.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2020, Data61, CSIRO (ABN 41 687 119 230)
+ *
+ * SPDX-License-Identifier: GPL-2.0-only
+ */
+
+#include <devices_gen.h>
+#include <drivers/common.h>
+#include <mode/arm_generic_timer.h>
+
+#include <elfloader_common.h>
+
+
+static unsigned int do_reset_cntvoff;
+
+/* Reset the virtual offset for the platform timer to 0 */
+#if CONFIG_MAX_NUM_NODES > 1
+void generic_timer_non_boot_init(void)
+{
+    if (do_reset_cntvoff) {
+        reset_cntvoff();
+    }
+}
+#endif
+
+
+static int generic_timer_init(UNUSED struct elfloader_device *dev, UNUSED void *match_data)
+{
+    do_reset_cntvoff = 1;
+    reset_cntvoff();
+    return 0;
+}
+
+static const struct dtb_match_table generic_timer_matches[] = {
+    { .compatible = "arm,armv7-timer" },
+    { .compatible = "arm,armv8-timer" },
+    { .compatible = NULL /* sentinel */ },
+};
+
+static const struct elfloader_driver generic_timer = {
+    .match_table = generic_timer_matches,
+    .type = DRIVER_TIMER,
+    .init = &generic_timer_init,
+    .ops = NULL,
+};
+
+ELFLOADER_DRIVER(generic_timer);