+
+#ifdef CONFIG_ACPI
+static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags)
+{
+ int trigger, polarity;
+
+ if (!interrupt)
+ return 0;
+
+ trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
+ : ACPI_LEVEL_SENSITIVE;
+
+ polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
+ : ACPI_ACTIVE_HIGH;
+
+ return acpi_register_gsi(NULL, interrupt, trigger, polarity);
+}
+
+/* Initialize per-processor generic timer */
+static int __init arch_timer_acpi_init(struct acpi_table_header *table)
+{
+ struct acpi_table_gtdt *gtdt;
+
+ if (arch_timers_present & ARCH_CP15_TIMER) {
+ pr_warn("arch_timer: already initialized, skipping\n");
+ return -EINVAL;
+ }
+
+ gtdt = container_of(table, struct acpi_table_gtdt, header);
+
+ arch_timers_present |= ARCH_CP15_TIMER;
+
+ arch_timer_ppi[PHYS_SECURE_PPI] =
+ map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
+ gtdt->secure_el1_flags);
+
+ arch_timer_ppi[PHYS_NONSECURE_PPI] =
+ map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
+ gtdt->non_secure_el1_flags);
+
+ arch_timer_ppi[VIRT_PPI] =
+ map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
+ gtdt->virtual_timer_flags);
+
+ arch_timer_ppi[HYP_PPI] =
+ map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
+ gtdt->non_secure_el2_flags);
+
+ /* Get the frequency from CNTFRQ */
+ arch_timer_detect_rate(NULL, NULL);
+
+ /* Always-on capability */
+ arch_timer_c3stop = !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
+
+ arch_timer_init();
+ return 0;
+}
+
+/* Initialize all the generic timers presented in GTDT */
+void __init acpi_generic_timer_init(void)
+{
+ if (acpi_disabled)
+ return;
+
+ acpi_table_parse(ACPI_SIG_GTDT, arch_timer_acpi_init);
+}
+#endif