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 Acked-by: Rafael J. Wysocki rafael.j.wysocki@intel.com --- arch/arm64/Kconfig | 1 + drivers/acpi/arm64/Kconfig | 3 + drivers/acpi/arm64/Makefile | 1 + drivers/acpi/arm64/gtdt.c | 152 ++++++++++++++++++++++++++++++++++++++++++++ drivers/clocksource/Kconfig | 1 - include/linux/acpi.h | 6 ++ 6 files changed, 163 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index bc3f00f..0607728 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 ACPI_MCFG if ACPI select ARCH_HAS_DEVMEM_IS_ALLOWED diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig index 4616da4..5a6f80f 100644 --- a/drivers/acpi/arm64/Kconfig +++ b/drivers/acpi/arm64/Kconfig @@ -4,3 +4,6 @@
config ACPI_IORT bool + +config ACPI_GTDT + bool diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile index 72331f2..1017def 100644 --- a/drivers/acpi/arm64/Makefile +++ b/drivers/acpi/arm64/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_ACPI_IORT) += iort.o +obj-$(CONFIG_ACPI_GTDT) += gtdt.o diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c new file mode 100644 index 0000000..b24844d --- /dev/null +++ b/drivers/acpi/arm64/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 + +struct acpi_gtdt_descriptor { + struct acpi_table_gtdt *gtdt; + void *platform_timer_start; + void *gtdt_end; +}; + +static struct acpi_gtdt_descriptor 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_gt_gsi(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_gt_gsi(gtdt->secure_el1_interrupt, + gtdt->secure_el1_flags); + case PHYS_NONSECURE_PPI: + return map_gt_gsi(gtdt->non_secure_el1_interrupt, + gtdt->non_secure_el1_flags); + case VIRT_PPI: + return map_gt_gsi(gtdt->virtual_timer_interrupt, + gtdt->virtual_timer_flags); + + case HYP_PPI: + return map_gt_gsi(gtdt->non_secure_el2_interrupt, + gtdt->non_secure_el2_flags); + default: + pr_err("Failed to map timer interrupt: 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 retrieve timer info from firmware: invalid data.\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 5677886..b58d259 100644 --- a/drivers/clocksource/Kconfig +++ b/drivers/clocksource/Kconfig @@ -285,7 +285,6 @@ config CLKSRC_MPS2 config ARM_ARCH_TIMER bool select CLKSRC_OF if OF - select CLKSRC_ACPI if ACPI
config ARM_ARCH_TIMER_EVTSTREAM bool "Enable ARM architected timer event stream generation by default" diff --git a/include/linux/acpi.h b/include/linux/acpi.h index c5eaf2f..e2f9841 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -567,6 +567,12 @@ enum acpi_reconfig_event { int acpi_reconfig_notifier_register(struct notifier_block *nb); int acpi_reconfig_notifier_unregister(struct notifier_block *nb);
+#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