diff mbox

[v8,5/9] acpi/arm64: Add GTDT table parse driver

Message ID 1468952284-28942-6-git-send-email-fu.wei@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

fu.wei@linaro.org July 19, 2016, 6:18 p.m. UTC
From: Fu Wei <fu.wei@linaro.org>

This patch adds support for parsing arch timer in GTDT,
provides some kernel APIs to parse all the PPIs and
always-on info in GTDT and export them.

By this driver, we can simplify arm_arch_timer drivers, and
separate the ACPI GTDT knowledge from it.

Signed-off-by: Fu Wei <fu.wei@linaro.org>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 arch/arm64/Kconfig             |   1 +
 drivers/acpi/Kconfig           |   5 ++
 drivers/acpi/Makefile          |   1 +
 drivers/acpi/arm64/Kconfig     |   5 ++
 drivers/acpi/arm64/Makefile    |   1 +
 drivers/acpi/arm64/acpi_gtdt.c | 152 +++++++++++++++++++++++++++++++++++++++++
 drivers/clocksource/Kconfig    |   1 -
 include/linux/acpi.h           |   6 ++
 8 files changed, 171 insertions(+), 1 deletion(-)

Comments

Rafael J. Wysocki July 21, 2016, 1:28 p.m. UTC | #1
On Wednesday, July 20, 2016 02:18:00 AM fu.wei@linaro.org wrote:
> From: Fu Wei <fu.wei@linaro.org>
> 
> This patch adds support for parsing arch timer in GTDT,
> provides some kernel APIs to parse all the PPIs and
> always-on info in GTDT and export them.
> 
> By this driver, we can simplify arm_arch_timer drivers, and
> separate the ACPI GTDT knowledge from it.
> 
> Signed-off-by: Fu Wei <fu.wei@linaro.org>
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
>  arch/arm64/Kconfig             |   1 +
>  drivers/acpi/Kconfig           |   5 ++
>  drivers/acpi/Makefile          |   1 +
>  drivers/acpi/arm64/Kconfig     |   5 ++
>  drivers/acpi/arm64/Makefile    |   1 +
>  drivers/acpi/arm64/acpi_gtdt.c | 152 +++++++++++++++++++++++++++++++++++++++++
>  drivers/clocksource/Kconfig    |   1 -
>  include/linux/acpi.h           |   6 ++
>  8 files changed, 171 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 5a0a691..0b9fba7 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -2,6 +2,7 @@ config ARM64
>  	def_bool y
>  	select ACPI_CCA_REQUIRED if ACPI
>  	select ACPI_GENERIC_GSI if ACPI
> +	select ACPI_GTDT if ACPI
>  	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
>  	select ARCH_HAS_DEVMEM_IS_ALLOWED
>  	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> index b7e2e77..1cdc7d2 100644
> --- a/drivers/acpi/Kconfig
> +++ b/drivers/acpi/Kconfig
> @@ -521,4 +521,9 @@ config XPOWER_PMIC_OPREGION
>  
>  endif
>  
> +if ARM64
> +source "drivers/acpi/arm64/Kconfig"
> +
> +endif
> +
>  endif	# ACPI
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 251ce85..1a94ff7 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -99,5 +99,6 @@ obj-$(CONFIG_ACPI_EXTLOG)	+= acpi_extlog.o
>  obj-$(CONFIG_PMIC_OPREGION)	+= pmic/intel_pmic.o
>  obj-$(CONFIG_CRC_PMIC_OPREGION) += pmic/intel_pmic_crc.o
>  obj-$(CONFIG_XPOWER_PMIC_OPREGION) += pmic/intel_pmic_xpower.o
> +obj-$(CONFIG_ARM64)	+= arm64/
>  
>  video-objs			+= acpi_video.o video_detect.o
> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
> new file mode 100644
> index 0000000..80201be
> --- /dev/null
> +++ b/drivers/acpi/arm64/Kconfig
> @@ -0,0 +1,5 @@
> +#
> +# ACPI Configuration for ARM64
> +#
> +config ACPI_GTDT
> +	bool
> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
> new file mode 100644
> index 0000000..466de6b
> --- /dev/null
> +++ b/drivers/acpi/arm64/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_ACPI_GTDT)		+= acpi_gtdt.o
> diff --git a/drivers/acpi/arm64/acpi_gtdt.c b/drivers/acpi/arm64/acpi_gtdt.c
> new file mode 100644
> index 0000000..e1cfc9e
> --- /dev/null
> +++ b/drivers/acpi/arm64/acpi_gtdt.c
> @@ -0,0 +1,152 @@
> +/*
> + * ARM Specific GTDT table Support
> + *
> + * Copyright (C) 2016, Linaro Ltd.
> + * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
> + *         Fu Wei <fu.wei@linaro.org>
> + *         Hanjun Guo <hanjun.guo@linaro.org>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +
> +#include <clocksource/arm_arch_timer.h>
> +
> +#undef pr_fmt
> +#define pr_fmt(fmt) "ACPI GTDT: " fmt
> +
> +typedef struct {
> +	struct acpi_table_gtdt *gtdt;
> +	void *platform_timer_start;
> +	void *gtdt_end;
> +} acpi_gtdt_desc_t;
> +
> +static acpi_gtdt_desc_t acpi_gtdt_desc __initdata;
> +
> +static inline void *next_platform_timer(void *platform_timer)
> +{
> +	struct acpi_gtdt_header *gh = platform_timer;
> +
> +	platform_timer += gh->length;
> +	if (platform_timer < acpi_gtdt_desc.gtdt_end)
> +		return platform_timer;
> +
> +	return NULL;
> +}
> +
> +#define for_each_platform_timer(_g)				\
> +	for (_g = acpi_gtdt_desc.platform_timer_start; _g;	\
> +	     _g = next_platform_timer(_g))
> +
> +static inline bool is_timer_block(void *platform_timer)
> +{
> +	struct acpi_gtdt_header *gh = platform_timer;
> +
> +	return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK;
> +}
> +
> +static inline bool is_watchdog(void *platform_timer)
> +{
> +	struct acpi_gtdt_header *gh = platform_timer;
> +
> +	return gh->type == ACPI_GTDT_TYPE_WATCHDOG;
> +}
> +
> +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);
> +}
> +
> +/*
> + * Map the PPIs of per-cpu arch_timer.
> + * @type: the type of PPI
> + * Returns 0 if error.
> + */
> +int __init acpi_gtdt_map_ppi(int type)
> +{
> +	struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
> +
> +	switch (type) {
> +	case PHYS_SECURE_PPI:
> +		return map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
> +						   gtdt->secure_el1_flags);
> +	case PHYS_NONSECURE_PPI:
> +		return map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
> +						   gtdt->non_secure_el1_flags);
> +	case VIRT_PPI:
> +		return map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
> +						   gtdt->virtual_timer_flags);
> +
> +	case HYP_PPI:
> +		return map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
> +						   gtdt->non_secure_el2_flags);
> +	default:
> +		pr_err("Map PPI failed: invalid type.\n");
> +	}
> +
> +	return 0;
> +}
> +
> +/*
> + * acpi_gtdt_c3stop - got c3stop info from GTDT
> + *
> + * Returns 1 if the timer is powered in deep idle state, 0 otherwise.
> + */
> +bool __init acpi_gtdt_c3stop(void)
> +{
> +	struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
> +
> +	return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
> +}
> +
> +/*
> + * Get some basic info from GTDT table, and init the global variables above
> + * for all timers initialization of Generic Timer.
> + * This function does some validation on GTDT table.
> + */
> +int __init acpi_gtdt_init(struct acpi_table_header *table)
> +{
> +	void *start;
> +	struct acpi_table_gtdt *gtdt;
> +
> +	gtdt = container_of(table, struct acpi_table_gtdt, header);
> +
> +	acpi_gtdt_desc.gtdt = gtdt;
> +	acpi_gtdt_desc.gtdt_end = (void *)table + table->length;
> +
> +	if (table->revision < 2) {
> +		pr_debug("Revision:%d doesn't support Platform Timers.\n",
> +			 table->revision);
> +		return 0;
> +	}
> +
> +	if (!gtdt->platform_timer_count) {
> +		pr_debug("No Platform Timer.\n");
> +		return 0;
> +	}
> +
> +	start = (void *)gtdt + gtdt->platform_timer_offset;
> +	if (start < (void *)table + sizeof(struct acpi_table_gtdt)) {
> +		pr_err(FW_BUG "Failed to init table: ACPI/GTDT is buggy.\n");

I would prefer something like

		pr_err(FW_BUG "Failed to retrieve timer information from firmware (invalid data)\n");

which is clear enough IMO and doesn't require whoever reads this message
to know anything about ACPI/GTDT etc.

Thanks,
Rafael
fu.wei@linaro.org July 22, 2016, 5:57 p.m. UTC | #2
Hi Rafael,

On 21 July 2016 at 21:28, Rafael J. Wysocki <rjw@rjwysocki.net> wrote:
> On Wednesday, July 20, 2016 02:18:00 AM fu.wei@linaro.org wrote:
>> From: Fu Wei <fu.wei@linaro.org>
>>
>> This patch adds support for parsing arch timer in GTDT,
>> provides some kernel APIs to parse all the PPIs and
>> always-on info in GTDT and export them.
>>
>> By this driver, we can simplify arm_arch_timer drivers, and
>> separate the ACPI GTDT knowledge from it.
>>
>> Signed-off-by: Fu Wei <fu.wei@linaro.org>
>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
>> ---
>>  arch/arm64/Kconfig             |   1 +
>>  drivers/acpi/Kconfig           |   5 ++
>>  drivers/acpi/Makefile          |   1 +
>>  drivers/acpi/arm64/Kconfig     |   5 ++
>>  drivers/acpi/arm64/Makefile    |   1 +
>>  drivers/acpi/arm64/acpi_gtdt.c | 152 +++++++++++++++++++++++++++++++++++++++++
>>  drivers/clocksource/Kconfig    |   1 -
>>  include/linux/acpi.h           |   6 ++
>>  8 files changed, 171 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 5a0a691..0b9fba7 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -2,6 +2,7 @@ config ARM64
>>       def_bool y
>>       select ACPI_CCA_REQUIRED if ACPI
>>       select ACPI_GENERIC_GSI if ACPI
>> +     select ACPI_GTDT if ACPI
>>       select ACPI_REDUCED_HARDWARE_ONLY if ACPI
>>       select ARCH_HAS_DEVMEM_IS_ALLOWED
>>       select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
>> index b7e2e77..1cdc7d2 100644
>> --- a/drivers/acpi/Kconfig
>> +++ b/drivers/acpi/Kconfig
>> @@ -521,4 +521,9 @@ config XPOWER_PMIC_OPREGION
>>
>>  endif
>>
>> +if ARM64
>> +source "drivers/acpi/arm64/Kconfig"
>> +
>> +endif
>> +
>>  endif        # ACPI
>> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
>> index 251ce85..1a94ff7 100644
>> --- a/drivers/acpi/Makefile
>> +++ b/drivers/acpi/Makefile
>> @@ -99,5 +99,6 @@ obj-$(CONFIG_ACPI_EXTLOG)   += acpi_extlog.o
>>  obj-$(CONFIG_PMIC_OPREGION)  += pmic/intel_pmic.o
>>  obj-$(CONFIG_CRC_PMIC_OPREGION) += pmic/intel_pmic_crc.o
>>  obj-$(CONFIG_XPOWER_PMIC_OPREGION) += pmic/intel_pmic_xpower.o
>> +obj-$(CONFIG_ARM64)  += arm64/
>>
>>  video-objs                   += acpi_video.o video_detect.o
>> diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
>> new file mode 100644
>> index 0000000..80201be
>> --- /dev/null
>> +++ b/drivers/acpi/arm64/Kconfig
>> @@ -0,0 +1,5 @@
>> +#
>> +# ACPI Configuration for ARM64
>> +#
>> +config ACPI_GTDT
>> +     bool
>> diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
>> new file mode 100644
>> index 0000000..466de6b
>> --- /dev/null
>> +++ b/drivers/acpi/arm64/Makefile
>> @@ -0,0 +1 @@
>> +obj-$(CONFIG_ACPI_GTDT)              += acpi_gtdt.o
>> diff --git a/drivers/acpi/arm64/acpi_gtdt.c b/drivers/acpi/arm64/acpi_gtdt.c
>> new file mode 100644
>> index 0000000..e1cfc9e
>> --- /dev/null
>> +++ b/drivers/acpi/arm64/acpi_gtdt.c
>> @@ -0,0 +1,152 @@
>> +/*
>> + * ARM Specific GTDT table Support
>> + *
>> + * Copyright (C) 2016, Linaro Ltd.
>> + * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
>> + *         Fu Wei <fu.wei@linaro.org>
>> + *         Hanjun Guo <hanjun.guo@linaro.org>
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License version 2 as
>> + * published by the Free Software Foundation.
>> + */
>> +
>> +#include <linux/acpi.h>
>> +#include <linux/init.h>
>> +#include <linux/kernel.h>
>> +
>> +#include <clocksource/arm_arch_timer.h>
>> +
>> +#undef pr_fmt
>> +#define pr_fmt(fmt) "ACPI GTDT: " fmt
>> +
>> +typedef struct {
>> +     struct acpi_table_gtdt *gtdt;
>> +     void *platform_timer_start;
>> +     void *gtdt_end;
>> +} acpi_gtdt_desc_t;
>> +
>> +static acpi_gtdt_desc_t acpi_gtdt_desc __initdata;
>> +
>> +static inline void *next_platform_timer(void *platform_timer)
>> +{
>> +     struct acpi_gtdt_header *gh = platform_timer;
>> +
>> +     platform_timer += gh->length;
>> +     if (platform_timer < acpi_gtdt_desc.gtdt_end)
>> +             return platform_timer;
>> +
>> +     return NULL;
>> +}
>> +
>> +#define for_each_platform_timer(_g)                          \
>> +     for (_g = acpi_gtdt_desc.platform_timer_start; _g;      \
>> +          _g = next_platform_timer(_g))
>> +
>> +static inline bool is_timer_block(void *platform_timer)
>> +{
>> +     struct acpi_gtdt_header *gh = platform_timer;
>> +
>> +     return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK;
>> +}
>> +
>> +static inline bool is_watchdog(void *platform_timer)
>> +{
>> +     struct acpi_gtdt_header *gh = platform_timer;
>> +
>> +     return gh->type == ACPI_GTDT_TYPE_WATCHDOG;
>> +}
>> +
>> +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);
>> +}
>> +
>> +/*
>> + * Map the PPIs of per-cpu arch_timer.
>> + * @type: the type of PPI
>> + * Returns 0 if error.
>> + */
>> +int __init acpi_gtdt_map_ppi(int type)
>> +{
>> +     struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
>> +
>> +     switch (type) {
>> +     case PHYS_SECURE_PPI:
>> +             return map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
>> +                                                gtdt->secure_el1_flags);
>> +     case PHYS_NONSECURE_PPI:
>> +             return map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
>> +                                                gtdt->non_secure_el1_flags);
>> +     case VIRT_PPI:
>> +             return map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
>> +                                                gtdt->virtual_timer_flags);
>> +
>> +     case HYP_PPI:
>> +             return map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
>> +                                                gtdt->non_secure_el2_flags);
>> +     default:
>> +             pr_err("Map PPI failed: invalid type.\n");
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> +/*
>> + * acpi_gtdt_c3stop - got c3stop info from GTDT
>> + *
>> + * Returns 1 if the timer is powered in deep idle state, 0 otherwise.
>> + */
>> +bool __init acpi_gtdt_c3stop(void)
>> +{
>> +     struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
>> +
>> +     return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
>> +}
>> +
>> +/*
>> + * Get some basic info from GTDT table, and init the global variables above
>> + * for all timers initialization of Generic Timer.
>> + * This function does some validation on GTDT table.
>> + */
>> +int __init acpi_gtdt_init(struct acpi_table_header *table)
>> +{
>> +     void *start;
>> +     struct acpi_table_gtdt *gtdt;
>> +
>> +     gtdt = container_of(table, struct acpi_table_gtdt, header);
>> +
>> +     acpi_gtdt_desc.gtdt = gtdt;
>> +     acpi_gtdt_desc.gtdt_end = (void *)table + table->length;
>> +
>> +     if (table->revision < 2) {
>> +             pr_debug("Revision:%d doesn't support Platform Timers.\n",
>> +                      table->revision);
>> +             return 0;
>> +     }
>> +
>> +     if (!gtdt->platform_timer_count) {
>> +             pr_debug("No Platform Timer.\n");
>> +             return 0;
>> +     }
>> +
>> +     start = (void *)gtdt + gtdt->platform_timer_offset;
>> +     if (start < (void *)table + sizeof(struct acpi_table_gtdt)) {
>> +             pr_err(FW_BUG "Failed to init table: ACPI/GTDT is buggy.\n");
>
> I would prefer something like
>
>                 pr_err(FW_BUG "Failed to retrieve timer information from firmware (invalid data)\n");
>
> which is clear enough IMO and doesn't require whoever reads this message
> to know anything about ACPI/GTDT etc.

OK, NP, I will do, and Thanks for your suggestion :-)
I will also check other pr_* , see If I can update them

thanks

>
> Thanks,
> Rafael
>
diff mbox

Patch

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 5a0a691..0b9fba7 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -2,6 +2,7 @@  config ARM64
 	def_bool y
 	select ACPI_CCA_REQUIRED if ACPI
 	select ACPI_GENERIC_GSI if ACPI
+	select ACPI_GTDT if ACPI
 	select ACPI_REDUCED_HARDWARE_ONLY if ACPI
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index b7e2e77..1cdc7d2 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -521,4 +521,9 @@  config XPOWER_PMIC_OPREGION
 
 endif
 
+if ARM64
+source "drivers/acpi/arm64/Kconfig"
+
+endif
+
 endif	# ACPI
diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
index 251ce85..1a94ff7 100644
--- a/drivers/acpi/Makefile
+++ b/drivers/acpi/Makefile
@@ -99,5 +99,6 @@  obj-$(CONFIG_ACPI_EXTLOG)	+= acpi_extlog.o
 obj-$(CONFIG_PMIC_OPREGION)	+= pmic/intel_pmic.o
 obj-$(CONFIG_CRC_PMIC_OPREGION) += pmic/intel_pmic_crc.o
 obj-$(CONFIG_XPOWER_PMIC_OPREGION) += pmic/intel_pmic_xpower.o
+obj-$(CONFIG_ARM64)	+= arm64/
 
 video-objs			+= acpi_video.o video_detect.o
diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig
new file mode 100644
index 0000000..80201be
--- /dev/null
+++ b/drivers/acpi/arm64/Kconfig
@@ -0,0 +1,5 @@ 
+#
+# ACPI Configuration for ARM64
+#
+config ACPI_GTDT
+	bool
diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
new file mode 100644
index 0000000..466de6b
--- /dev/null
+++ b/drivers/acpi/arm64/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_ACPI_GTDT)		+= acpi_gtdt.o
diff --git a/drivers/acpi/arm64/acpi_gtdt.c b/drivers/acpi/arm64/acpi_gtdt.c
new file mode 100644
index 0000000..e1cfc9e
--- /dev/null
+++ b/drivers/acpi/arm64/acpi_gtdt.c
@@ -0,0 +1,152 @@ 
+/*
+ * ARM Specific GTDT table Support
+ *
+ * Copyright (C) 2016, Linaro Ltd.
+ * Author: Daniel Lezcano <daniel.lezcano@linaro.org>
+ *         Fu Wei <fu.wei@linaro.org>
+ *         Hanjun Guo <hanjun.guo@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/acpi.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+
+#include <clocksource/arm_arch_timer.h>
+
+#undef pr_fmt
+#define pr_fmt(fmt) "ACPI GTDT: " fmt
+
+typedef struct {
+	struct acpi_table_gtdt *gtdt;
+	void *platform_timer_start;
+	void *gtdt_end;
+} acpi_gtdt_desc_t;
+
+static acpi_gtdt_desc_t acpi_gtdt_desc __initdata;
+
+static inline void *next_platform_timer(void *platform_timer)
+{
+	struct acpi_gtdt_header *gh = platform_timer;
+
+	platform_timer += gh->length;
+	if (platform_timer < acpi_gtdt_desc.gtdt_end)
+		return platform_timer;
+
+	return NULL;
+}
+
+#define for_each_platform_timer(_g)				\
+	for (_g = acpi_gtdt_desc.platform_timer_start; _g;	\
+	     _g = next_platform_timer(_g))
+
+static inline bool is_timer_block(void *platform_timer)
+{
+	struct acpi_gtdt_header *gh = platform_timer;
+
+	return gh->type == ACPI_GTDT_TYPE_TIMER_BLOCK;
+}
+
+static inline bool is_watchdog(void *platform_timer)
+{
+	struct acpi_gtdt_header *gh = platform_timer;
+
+	return gh->type == ACPI_GTDT_TYPE_WATCHDOG;
+}
+
+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);
+}
+
+/*
+ * Map the PPIs of per-cpu arch_timer.
+ * @type: the type of PPI
+ * Returns 0 if error.
+ */
+int __init acpi_gtdt_map_ppi(int type)
+{
+	struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
+
+	switch (type) {
+	case PHYS_SECURE_PPI:
+		return map_generic_timer_interrupt(gtdt->secure_el1_interrupt,
+						   gtdt->secure_el1_flags);
+	case PHYS_NONSECURE_PPI:
+		return map_generic_timer_interrupt(gtdt->non_secure_el1_interrupt,
+						   gtdt->non_secure_el1_flags);
+	case VIRT_PPI:
+		return map_generic_timer_interrupt(gtdt->virtual_timer_interrupt,
+						   gtdt->virtual_timer_flags);
+
+	case HYP_PPI:
+		return map_generic_timer_interrupt(gtdt->non_secure_el2_interrupt,
+						   gtdt->non_secure_el2_flags);
+	default:
+		pr_err("Map PPI failed: invalid type.\n");
+	}
+
+	return 0;
+}
+
+/*
+ * acpi_gtdt_c3stop - got c3stop info from GTDT
+ *
+ * Returns 1 if the timer is powered in deep idle state, 0 otherwise.
+ */
+bool __init acpi_gtdt_c3stop(void)
+{
+	struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt;
+
+	return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON);
+}
+
+/*
+ * Get some basic info from GTDT table, and init the global variables above
+ * for all timers initialization of Generic Timer.
+ * This function does some validation on GTDT table.
+ */
+int __init acpi_gtdt_init(struct acpi_table_header *table)
+{
+	void *start;
+	struct acpi_table_gtdt *gtdt;
+
+	gtdt = container_of(table, struct acpi_table_gtdt, header);
+
+	acpi_gtdt_desc.gtdt = gtdt;
+	acpi_gtdt_desc.gtdt_end = (void *)table + table->length;
+
+	if (table->revision < 2) {
+		pr_debug("Revision:%d doesn't support Platform Timers.\n",
+			 table->revision);
+		return 0;
+	}
+
+	if (!gtdt->platform_timer_count) {
+		pr_debug("No Platform Timer.\n");
+		return 0;
+	}
+
+	start = (void *)gtdt + gtdt->platform_timer_offset;
+	if (start < (void *)table + sizeof(struct acpi_table_gtdt)) {
+		pr_err(FW_BUG "Failed to init table: ACPI/GTDT is buggy.\n");
+		return -EINVAL;
+	}
+	acpi_gtdt_desc.platform_timer_start = start;
+
+	return gtdt->platform_timer_count;
+}
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index 47352d2..108dbc3 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -205,7 +205,6 @@  config CLKSRC_MPS2
 config ARM_ARCH_TIMER
 	bool
 	select CLKSRC_OF if OF
-	select CLKSRC_ACPI if ACPI
 
 config ARM_ARCH_TIMER_EVTSTREAM
 	bool "Support for ARM architected timer event stream generation"
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 288fac5..fb8b689 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -532,6 +532,12 @@  void acpi_walk_dep_device_list(acpi_handle handle);
 struct platform_device *acpi_create_platform_device(struct acpi_device *);
 #define ACPI_PTR(_ptr)	(_ptr)
 
+#ifdef CONFIG_ACPI_GTDT
+int acpi_gtdt_init(struct acpi_table_header *table);
+int acpi_gtdt_map_ppi(int type);
+bool acpi_gtdt_c3stop(void);
+#endif
+
 #else	/* !CONFIG_ACPI */
 
 #define acpi_disabled 1