From: Shannon Zhao <shannon.z...@linaro.org>
Parse GTDT (Generic Timer Descriptor Table) to initialize timer. Using
the information presented by GTDT to initialize the arch timer (not
memory-mapped).
Signed-off-by: Parth Dixit <parth.di...@linaro.org>
Signed-off-by: Shannon Zhao <shannon.z...@linaro.org>
Reviewed-by: Stefano Stabellini <stefano.stabell...@eu.citrix.com>
---
xen/arch/arm/time.c | 86 +++++++++++++++++++++++++++++++++++++++++++----------
1 file changed, 70 insertions(+), 16 deletions(-)
diff --git a/xen/arch/arm/time.c b/xen/arch/arm/time.c
index 73a1a3e..5f8f974 100644
--- a/xen/arch/arm/time.c
+++ b/xen/arch/arm/time.c
@@ -29,6 +29,7 @@
#include <xen/time.h>
#include <xen/sched.h>
#include <xen/event.h>
+#include <xen/acpi.h>
#include <asm/system.h>
#include <asm/time.h>
#include <asm/gic.h>
@@ -65,8 +66,51 @@ unsigned int timer_get_irq(enum timer_ppi ppi)
static __initdata struct dt_device_node *timer;
+#ifdef CONFIG_ACPI
+static u32 __init acpi_get_timer_irq_type(u32 flags)
+{
+ return (flags & ACPI_GTDT_INTERRUPT_MODE) ? IRQ_TYPE_EDGE_BOTH
+ : IRQ_TYPE_LEVEL_MASK;
+}
+
+/* Initialize per-processor generic timer */
+static int __init arch_timer_acpi_init(struct acpi_table_header *header)
+{
+ u32 irq_type;
+ struct acpi_table_gtdt *gtdt;
+
+ gtdt = container_of(header, struct acpi_table_gtdt, header);
+
+ /* Initialize all the generic timer IRQ variable from GTDT table */
+ irq_type = acpi_get_timer_irq_type(gtdt->non_secure_el1_flags);
+ irq_set_type(gtdt->non_secure_el1_interrupt, irq_type);
+ timer_irq[TIMER_PHYS_NONSECURE_PPI] = gtdt->non_secure_el1_interrupt;
+
+ irq_type = acpi_get_timer_irq_type(gtdt->secure_el1_flags);
+ irq_set_type(gtdt->secure_el1_interrupt, irq_type);
+ timer_irq[TIMER_PHYS_SECURE_PPI] = gtdt->secure_el1_interrupt;
+
+ irq_type = acpi_get_timer_irq_type(gtdt->virtual_timer_flags);
+ irq_set_type(gtdt->virtual_timer_interrupt, irq_type);
+ timer_irq[TIMER_VIRT_PPI] = gtdt->virtual_timer_interrupt;
+
+ irq_type = acpi_get_timer_irq_type(gtdt->non_secure_el2_flags);
+ irq_set_type(gtdt->non_secure_el2_interrupt, irq_type);
+ timer_irq[TIMER_HYP_PPI] = gtdt->non_secure_el2_interrupt;
+
+ return 0;
+}
+
+static void __init preinit_acpi_xen_time(void)
+{
+ acpi_table_parse(ACPI_SIG_GTDT, arch_timer_acpi_init);
+}
+#else
+static void __init preinit_acpi_xen_time(void) { }
+#endif
+
/* Set up the timer on the boot CPU (early init function) */
-void __init preinit_xen_time(void)
+static void __init preinit_dt_xen_time(void)
{
static const struct dt_device_match timer_ids[] __initconst =
{
@@ -75,6 +119,7 @@ void __init preinit_xen_time(void)
};
int res;
u32 rate;
+ unsigned int i;
timer = dt_find_matching_node(NULL, timer_ids);
if ( !timer )
@@ -82,27 +127,12 @@ void __init preinit_xen_time(void)
dt_device_set_used_by(timer, DOMID_XEN);
- res = platform_init_time();
- if ( res )
- panic("Timer: Cannot initialize platform timer");
-
res = dt_property_read_u32(timer, "clock-frequency", &rate);
if ( res )
{
cpu_khz = rate / 1000;
timer_dt_clock_frequency = rate;
}
- else
- cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
-
- boot_count = READ_SYSREG64(CNTPCT_EL0);
-}
-
-/* Set up the timer on the boot CPU (late init function) */
-int __init init_xen_time(void)
-{
- int res;
- unsigned int i;
/* Retrieve all IRQs for the timer */
for ( i = TIMER_PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++ )
@@ -113,7 +143,31 @@ int __init init_xen_time(void)
panic("Timer: Unable to retrieve IRQ %u from the device tree", i);
timer_irq[i] = res;
}
+}
+
+void __init preinit_xen_time(void)
+{
+ int res;
+
+ /* Initialize all the generic timers presented in GTDT */
+ if ( acpi_disabled )
+ preinit_dt_xen_time();
+ else
+ preinit_acpi_xen_time();
+
+ if ( !cpu_khz )
+ cpu_khz = READ_SYSREG32(CNTFRQ_EL0) / 1000;
+
+ res = platform_init_time();
+ if ( res )
+ panic("Timer: Cannot initialize platform timer");
+ boot_count = READ_SYSREG64(CNTPCT_EL0);
+}
+
+/* Set up the timer on the boot CPU (late init function) */
+int __init init_xen_time(void)
+{
/* Check that this CPU supports the Generic Timer interface */
if ( !cpu_has_gentimer )
panic("CPU does not support the Generic Timer v1 interface");
--
2.0.4
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