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 | 216 ++++++++++++++++++++++++++++++++++++++++++++ include/linux/acpi.h | 7 ++ 5 files changed, 228 insertions(+)
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 969ef88..4277a21 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..2de79aa --- /dev/null +++ b/drivers/acpi/arm64/gtdt.c @@ -0,0 +1,216 @@ +/* + * 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 *gtdt_end; + unsigned int timer_block_count; + unsigned int watchdog_count; +}; + +static struct acpi_gtdt_descriptor acpi_gtdt_desc __initdata; +static struct acpi_gtdt_timer_block **timer_block __initdata; +static struct acpi_gtdt_watchdog **watchdog __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; _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; + + 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. + * Note: Linux on arm64 isn't supported on the secure side. + * So we only handle the non-secure timer PPIs, + * ARCH_TIMER_PHYS_SECURE_PPI is treated as invalid type. + */ +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 + * @type: the type of PPI + * Returns 1 if the timer is powered in deep idle state, 0 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 0; +} + +/* + * Release the memory we have allocated in acpi_gtdt_init. + * This should be called, when the driver who called "acpi_gtdt_init" previously + * doesn't need the GTDT info anymore. + */ +void __init acpi_gtdt_release(void) +{ + kfree(timer_block); + kfree(watchdog); + timer_block = NULL; + watchdog = NULL; +} + +/* + * 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) +{ + int timer_count; + void *platform_timer; + struct acpi_table_gtdt *gtdt; + + gtdt = container_of(table, struct acpi_table_gtdt, header); + + if (table->revision < 2) { + pr_debug("Revision:%d doesn't support Platform Timers.\n", + table->revision); + timer_count = 0; + } else if (!gtdt->platform_timer_count) { + pr_debug("No Platform Timer.\n"); + timer_count = 0; + } else { + timer_count = gtdt->platform_timer_count; + } + + acpi_gtdt_desc.gtdt = gtdt; + acpi_gtdt_desc.gtdt_end = (void *)table + table->length; + + if (!timer_count) + return 0; + + platform_timer = (void *)gtdt + gtdt->platform_timer_offset; + if (platform_timer < (void *)table + sizeof(struct acpi_table_gtdt)) { + pr_err(FW_BUG "Failed to retrieve timer info from firmware: invalid data.\n"); + return -EINVAL; + } + + timer_block = kcalloc(timer_count, + sizeof(struct acpi_gtdt_timer_block *), + GFP_KERNEL); + if (!timer_block) + return -ENOMEM; + + watchdog = kcalloc(timer_count, sizeof(struct acpi_gtdt_watchdog *), + GFP_KERNEL); + if (!watchdog) { + kfree(timer_block); + timer_block = NULL; + return -ENOMEM; + } + + acpi_gtdt_desc.timer_block_count = 0; + acpi_gtdt_desc.watchdog_count = 0; + for_each_platform_timer(platform_timer) { + if (is_timer_block(platform_timer)) { + timer_block[acpi_gtdt_desc.timer_block_count++] = + platform_timer; + } else if (is_watchdog(platform_timer)) { + watchdog[acpi_gtdt_desc.watchdog_count++] = + platform_timer; + } else { + pr_err(FW_BUG "Invalid platform timer type.\n"); + goto error; + } + } + + if (timer_count == acpi_gtdt_desc.watchdog_count + + acpi_gtdt_desc.timer_block_count) + return 0; + + pr_err(FW_BUG "Invalid platform timer number.\n"); +error: + acpi_gtdt_release(); + return -EINVAL; +} diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 61a3d90..a1611d1 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -577,6 +577,13 @@ 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(int type); +void acpi_gtdt_release(void); +#endif + #else /* !CONFIG_ACPI */
#define acpi_disabled 1