From: Fu Wei <fu.wei@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
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@xxxxxxxxxx>
+ * Fu Wei <fu.wei@xxxxxxxxxx>
+ * Hanjun Guo <hanjun.guo@xxxxxxxxxx>
+ *
+ * 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
--
2.7.4
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