On Monday, February 02, 2015 08:45:45 PM Hanjun Guo wrote:
Using the information presented by GTDT (Generic Timer Description Table) to initialize the arch timer (not memory-mapped).
CC: Daniel Lezcano daniel.lezcano@linaro.org Originally-by: Amit Daniel Kachhap amit.daniel@samsung.com Tested-by: Suravee Suthikulpanit Suravee.Suthikulpanit@amd.com Tested-by: Yijing Wang wangyijing@huawei.com Tested-by: Mark Langsdorf mlangsdo@redhat.com Tested-by: Jon Masters jcm@redhat.com Tested-by: Timur Tabi timur@codeaurora.org Signed-off-by: Hanjun Guo hanjun.guo@linaro.org
arch/arm64/kernel/time.c | 7 ++ drivers/clocksource/arm_arch_timer.c | 132 ++++++++++++++++++++++++++++-------
An ACK from Thomas Gleixner is necessary for that.
include/linux/clocksource.h | 6 ++ 3 files changed, 118 insertions(+), 27 deletions(-)
diff --git a/arch/arm64/kernel/time.c b/arch/arm64/kernel/time.c index 1a7125c..42f9195 100644 --- a/arch/arm64/kernel/time.c +++ b/arch/arm64/kernel/time.c @@ -35,6 +35,7 @@ #include <linux/delay.h> #include <linux/clocksource.h> #include <linux/clk-provider.h> +#include <linux/acpi.h> #include <clocksource/arm_arch_timer.h> @@ -72,6 +73,12 @@ void __init time_init(void) tick_setup_hrtimer_broadcast();
- /*
* Since ACPI or FDT will only one be available in the system,
* we can use acpi_generic_timer_init() here safely
*/
- acpi_generic_timer_init();
- arch_timer_rate = arch_timer_get_rate(); if (!arch_timer_rate) panic("Unable to initialise architected timer.\n");
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 095c177..407aa63 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -21,6 +21,7 @@ #include <linux/io.h> #include <linux/slab.h> #include <linux/sched_clock.h> +#include <linux/acpi.h> #include <asm/arch_timer.h> #include <asm/virt.h> @@ -370,8 +371,12 @@ arch_timer_detect_rate(void __iomem *cntbase, struct device_node *np) if (arch_timer_rate) return;
- /* Try to determine the frequency from the device tree or CNTFRQ */
- if (of_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
- /*
* Try to determine the frequency from the device tree or CNTFRQ,
* if ACPI is enabled, get the frequency from CNTFRQ ONLY.
*/
- if (!acpi_disabled ||
if (cntbase) arch_timer_rate = readl_relaxed(cntbase + CNTFRQ); elseof_property_read_u32(np, "clock-frequency", &arch_timer_rate)) {
@@ -690,28 +695,8 @@ static void __init arch_timer_common_init(void) arch_timer_arch_init(); } -static void __init arch_timer_init(struct device_node *np) +static void __init arch_timer_init(void) {
- int i;
- if (arch_timers_present & ARCH_CP15_TIMER) {
pr_warn("arch_timer: multiple nodes in dt, skipping\n");
return;
- }
- arch_timers_present |= ARCH_CP15_TIMER;
- for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
- arch_timer_detect_rate(NULL, np);
- /*
* If we cannot rely on firmware initializing the timer registers then
* we should use the physical timers instead.
*/
- if (IS_ENABLED(CONFIG_ARM) &&
of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
arch_timer_use_virtual = false;
- /*
- If HYP mode is available, we know that the physical timer
- has been configured to be accessible from PL1. Use it, so
@@ -730,13 +715,39 @@ static void __init arch_timer_init(struct device_node *np) } }
- arch_timer_c3stop = !of_property_read_bool(np, "always-on");
- arch_timer_register(); arch_timer_common_init();
} -CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_init); -CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_init);
+static void __init arch_timer_of_init(struct device_node *np) +{
- int i;
- if (arch_timers_present & ARCH_CP15_TIMER) {
pr_warn("arch_timer: multiple nodes in dt, skipping\n");
return;
- }
- arch_timers_present |= ARCH_CP15_TIMER;
- for (i = PHYS_SECURE_PPI; i < MAX_TIMER_PPI; i++)
arch_timer_ppi[i] = irq_of_parse_and_map(np, i);
- arch_timer_detect_rate(NULL, np);
- arch_timer_c3stop = !of_property_read_bool(np, "always-on");
- /*
* If we cannot rely on firmware initializing the timer registers then
* we should use the physical timers instead.
*/
- if (IS_ENABLED(CONFIG_ARM) &&
of_property_read_bool(np, "arm,cpu-registers-not-fw-configured"))
arch_timer_use_virtual = false;
- arch_timer_init();
+} +CLOCKSOURCE_OF_DECLARE(armv7_arch_timer, "arm,armv7-timer", arch_timer_of_init); +CLOCKSOURCE_OF_DECLARE(armv8_arch_timer, "arm,armv8-timer", arch_timer_of_init); static void __init arch_timer_mem_init(struct device_node *np) { @@ -803,3 +814,70 @@ static void __init arch_timer_mem_init(struct device_node *np) } CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem", arch_timer_mem_init);
+#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 diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index abcafaa..af6155a 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -346,4 +346,10 @@ extern void clocksource_of_init(void); static inline void clocksource_of_init(void) {} #endif +#ifdef CONFIG_ACPI +void acpi_generic_timer_init(void); +#else +static inline void acpi_generic_timer_init(void) { } +#endif
#endif /* _LINUX_CLOCKSOURCE_H */