From: Fu Wei fu.wei@linaro.org
This patch adds support for parsing arch timer info 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 Tested-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Hanjun Guo hanjun.guo@linaro.org Tested-by: Hanjun Guo hanjun.guo@linaro.org Acked-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com --- arch/arm64/Kconfig | 1 + drivers/acpi/arm64/Kconfig | 3 + drivers/acpi/arm64/Makefile | 1 + drivers/acpi/arm64/gtdt.c | 157 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 6 ++ 5 files changed, 168 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3741859..7e2baec 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 ACPI_SPCR_TABLE if ACPI 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..3d95af8 --- /dev/null +++ b/drivers/acpi/arm64/gtdt.c @@ -0,0 +1,157 @@ +/* + * 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 - Store the key info of GTDT for all functions + * @gtdt: The pointer to the struct acpi_table_gtdt of GTDT table. + * @gtdt_end: The pointer to the end of GTDT table. + * @platform_timer: The pointer to the start of Platform Timer Structure + * + * The struct store the key info of GTDT table, it should be initialized by + * acpi_gtdt_init. + */ +struct acpi_gtdt_descriptor { + struct acpi_table_gtdt *gtdt; + void *gtdt_end; + void *platform_timer; +}; + +static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata; + +static int __init map_gt_gsi(u32 interrupt, u32 flags) +{ + int trigger, polarity; + + 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); +} + +/** + * acpi_gtdt_map_ppi() - Map the PPIs of per-cpu arch_timer. + * @type: the type of PPI. + * + * Note: Secure state is not managed by the kernel on ARM64 systems. + * So we only handle the non-secure timer PPIs, + * ARCH_TIMER_PHYS_SECURE_PPI is treated as invalid type. + * + * Return: the mapped PPI value, 0 if error. + */ +int __init acpi_gtdt_map_ppi(int type) +{ + struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; + + switch (type) { + case ARCH_TIMER_PHYS_NONSECURE_PPI: + return map_gt_gsi(gtdt->non_secure_el1_interrupt, + gtdt->non_secure_el1_flags); + case ARCH_TIMER_VIRT_PPI: + return map_gt_gsi(gtdt->virtual_timer_interrupt, + gtdt->virtual_timer_flags); + + case ARCH_TIMER_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 according to the type of PPI. + * @type: the type of PPI. + * + * Return: true if the timer HW state is lost when a CPU enters an idle state, + * false otherwise + */ +bool __init acpi_gtdt_c3stop(int type) +{ + struct acpi_table_gtdt *gtdt = acpi_gtdt_desc.gtdt; + + switch (type) { + case ARCH_TIMER_PHYS_NONSECURE_PPI: + return !(gtdt->non_secure_el1_flags & ACPI_GTDT_ALWAYS_ON); + + case ARCH_TIMER_VIRT_PPI: + return !(gtdt->virtual_timer_flags & ACPI_GTDT_ALWAYS_ON); + + case ARCH_TIMER_HYP_PPI: + return !(gtdt->non_secure_el2_flags & ACPI_GTDT_ALWAYS_ON); + + default: + pr_err("Failed to get c3stop info: invalid type.\n"); + } + + return false; +} + +/** + * acpi_gtdt_init() - Get the info of GTDT table to prepare for further init. + * @table: The pointer to GTDT table. + * @platform_timer_count: It points to a integer variable which is used + * for storing the number of platform timers. + * This pointer could be NULL, if the caller + * doesn't need this info. + * + * Return: 0 if success, -EINVAL if error. + */ +int __init acpi_gtdt_init(struct acpi_table_header *table, + int *platform_timer_count) +{ + void *platform_timer; + 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; + acpi_gtdt_desc.platform_timer = NULL; + if (platform_timer_count) + *platform_timer_count = 0; + + if (table->revision < 2) { + pr_warn("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; + } + + platform_timer = (void *)gtdt + gtdt->platform_timer_offset; + if (platform_timer < (void *)table + sizeof(struct acpi_table_gtdt)) { + pr_err(FW_BUG "invalid timer data.\n"); + return -EINVAL; + } + acpi_gtdt_desc.platform_timer = platform_timer; + if (platform_timer_count) + *platform_timer_count = gtdt->platform_timer_count; + + return 0; +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 9b05886..4b5c146 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -595,6 +595,12 @@ 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 *platform_timer_count); +int acpi_gtdt_map_ppi(int type); +bool acpi_gtdt_c3stop(int type); +#endif + #else /* !CONFIG_ACPI */
#define acpi_disabled 1