1 files changed, 417 insertions, 0 deletions

diff --git a/drivers/acpi/arm64/gtdt.c b/drivers/acpi/arm64/gtdt.c
new file mode 100644
index 0000000..597a737
--- /dev/null
+++ b/drivers/acpi/arm64/gtdt.c
@@ -0,0 +1,417 @@
+/*
+ * 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/irqdomain.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.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 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; _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_non_secure_watchdog(void *platform_timer)
+{
+	struct acpi_gtdt_header *gh = platform_timer;
+	struct acpi_gtdt_watchdog *wd = platform_timer;
+
+	if (gh->type != ACPI_GTDT_TYPE_WATCHDOG)
+		return false;
+
+	return !(wd->timer_flags & ACPI_GTDT_WATCHDOG_SECURE);
+}
+
+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;
+}
+
+static int __init gtdt_parse_timer_block(struct acpi_gtdt_timer_block *block,
+					 struct arch_timer_mem *timer_mem)
+{
+	int i;
+	struct arch_timer_mem_frame *frame;
+	struct acpi_gtdt_timer_entry *gtdt_frame;
+
+	if (!block->timer_count) {
+		pr_err(FW_BUG "GT block present, but frame count is zero.");
+		return -ENODEV;
+	}
+
+	if (block->timer_count > ARCH_TIMER_MEM_MAX_FRAMES) {
+		pr_err(FW_BUG "GT block lists %d frames, ACPI spec only allows 8\n",
+		       block->timer_count);
+		return -EINVAL;
+	}
+
+	timer_mem->cntctlbase = (phys_addr_t)block->block_address;
+	/*
+	 * The CNTCTLBase frame is 4KB (register offsets 0x000 - 0xFFC).
+	 * See ARM DDI 0487A.k_iss10775, page I1-5129, Table I1-3
+	 * "CNTCTLBase memory map".
+	 */
+	timer_mem->size = SZ_4K;
+
+	gtdt_frame = (void *)block + block->timer_offset;
+	if (gtdt_frame + block->timer_count != (void *)block + block->header.length)
+		return -EINVAL;
+
+	/*
+	 * Get the GT timer Frame data for every GT Block Timer
+	 */
+	for (i = 0; i < block->timer_count; i++, gtdt_frame++) {
+		if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER)
+			continue;
+		if (gtdt_frame->frame_number >= ARCH_TIMER_MEM_MAX_FRAMES ||
+		    !gtdt_frame->base_address || !gtdt_frame->timer_interrupt)
+			goto error;
+
+		frame = &timer_mem->frame[gtdt_frame->frame_number];
+
+		/* duplicate frame */
+		if (frame->valid)
+			goto error;
+
+		frame->phys_irq = map_gt_gsi(gtdt_frame->timer_interrupt,
+					     gtdt_frame->timer_flags);
+		if (frame->phys_irq <= 0) {
+			pr_warn("failed to map physical timer irq in frame %d.\n",
+				gtdt_frame->frame_number);
+			goto error;
+		}
+
+		if (gtdt_frame->virtual_timer_interrupt) {
+			frame->virt_irq =
+				map_gt_gsi(gtdt_frame->virtual_timer_interrupt,
+					   gtdt_frame->virtual_timer_flags);
+			if (frame->virt_irq <= 0) {
+				pr_warn("failed to map virtual timer irq in frame %d.\n",
+					gtdt_frame->frame_number);
+				goto error;
+			}
+		} else {
+			pr_debug("virtual timer in frame %d not implemented.\n",
+				 gtdt_frame->frame_number);
+		}
+
+		frame->cntbase = gtdt_frame->base_address;
+		/*
+		 * The CNTBaseN frame is 4KB (register offsets 0x000 - 0xFFC).
+		 * See ARM DDI 0487A.k_iss10775, page I1-5130, Table I1-4
+		 * "CNTBaseN memory map".
+		 */
+		frame->size = SZ_4K;
+		frame->valid = true;
+	}
+
+	return 0;
+
+error:
+	do {
+		if (gtdt_frame->common_flags & ACPI_GTDT_GT_IS_SECURE_TIMER ||
+		    gtdt_frame->frame_number >= ARCH_TIMER_MEM_MAX_FRAMES)
+			continue;
+
+		frame = &timer_mem->frame[gtdt_frame->frame_number];
+
+		if (frame->phys_irq > 0)
+			acpi_unregister_gsi(gtdt_frame->timer_interrupt);
+		frame->phys_irq = 0;
+
+		if (frame->virt_irq > 0)
+			acpi_unregister_gsi(gtdt_frame->virtual_timer_interrupt);
+		frame->virt_irq = 0;
+	} while (i-- >= 0 && gtdt_frame--);
+
+	return -EINVAL;
+}
+
+/**
+ * acpi_arch_timer_mem_init() - Get the info of all GT blocks in GTDT table.
+ * @timer_mem:	The pointer to the array of struct arch_timer_mem for returning
+ *		the result of parsing. The element number of this array should
+ *		be platform_timer_count(the total number of platform timers).
+ * @timer_count: It points to a integer variable which is used for storing the
+ *		number of GT blocks we have parsed.
+ *
+ * Return: 0 if success, -EINVAL/-ENODEV if error.
+ */
+int __init acpi_arch_timer_mem_init(struct arch_timer_mem *timer_mem,
+				    int *timer_count)
+{
+	int ret;
+	void *platform_timer;
+
+	*timer_count = 0;
+	for_each_platform_timer(platform_timer) {
+		if (is_timer_block(platform_timer)) {
+			ret = gtdt_parse_timer_block(platform_timer, timer_mem);
+			if (ret)
+				return ret;
+			timer_mem++;
+			(*timer_count)++;
+		}
+	}
+
+	if (*timer_count)
+		pr_info("found %d memory-mapped timer block(s).\n",
+			*timer_count);
+
+	return 0;
+}
+
+/*
+ * Initialize a SBSA generic Watchdog platform device info from GTDT
+ */
+static int __init gtdt_import_sbsa_gwdt(struct acpi_gtdt_watchdog *wd,
+					int index)
+{
+	struct platform_device *pdev;
+	int irq = map_gt_gsi(wd->timer_interrupt, wd->timer_flags);
+
+	/*
+	 * According to SBSA specification the size of refresh and control
+	 * frames of SBSA Generic Watchdog is SZ_4K(Offset 0x000 – 0xFFF).
+	 */
+	struct resource res[] = {
+		DEFINE_RES_MEM(wd->control_frame_address, SZ_4K),
+		DEFINE_RES_MEM(wd->refresh_frame_address, SZ_4K),
+		DEFINE_RES_IRQ(irq),
+	};
+	int nr_res = ARRAY_SIZE(res);
+
+	pr_debug("found a Watchdog (0x%llx/0x%llx gsi:%u flags:0x%x).\n",
+		 wd->refresh_frame_address, wd->control_frame_address,
+		 wd->timer_interrupt, wd->timer_flags);
+
+	if (!(wd->refresh_frame_address && wd->control_frame_address)) {
+		pr_err(FW_BUG "failed to get the Watchdog base address.\n");
+		acpi_unregister_gsi(wd->timer_interrupt);
+		return -EINVAL;
+	}
+
+	if (irq <= 0) {
+		pr_warn("failed to map the Watchdog interrupt.\n");
+		nr_res--;
+	}
+
+	/*
+	 * Add a platform device named "sbsa-gwdt" to match the platform driver.
+	 * "sbsa-gwdt": SBSA(Server Base System Architecture) Generic Watchdog
+	 * The platform driver can get device info below by matching this name.
+	 */
+	pdev = platform_device_register_simple("sbsa-gwdt", index, res, nr_res);
+	if (IS_ERR(pdev)) {
+		acpi_unregister_gsi(wd->timer_interrupt);
+		return PTR_ERR(pdev);
+	}
+
+	return 0;
+}
+
+static int __init gtdt_sbsa_gwdt_init(void)
+{
+	void *platform_timer;
+	struct acpi_table_header *table;
+	int ret, timer_count, gwdt_count = 0;
+
+	if (acpi_disabled)
+		return 0;
+
+	if (ACPI_FAILURE(acpi_get_table(ACPI_SIG_GTDT, 0, &table)))
+		return -EINVAL;
+
+	/*
+	 * Note: Even though the global variable acpi_gtdt_desc has been
+	 * initialized by acpi_gtdt_init() while initializing the arch timers,
+	 * when we call this function to get SBSA watchdogs info from GTDT, the
+	 * pointers stashed in it are stale (since they are early temporary
+	 * mappings carried out before acpi_permanent_mmap is set) and we need
+	 * to re-initialize them with permanent mapped pointer values to let the
+	 * GTDT parsing possible.
+	 */
+	ret = acpi_gtdt_init(table, &timer_count);
+	if (ret || !timer_count)
+		return ret;
+
+	for_each_platform_timer(platform_timer) {
+		if (is_non_secure_watchdog(platform_timer)) {
+			ret = gtdt_import_sbsa_gwdt(platform_timer, gwdt_count);
+			if (ret)
+				break;
+			gwdt_count++;
+		}
+	}
+
+	if (gwdt_count)
+		pr_info("found %d SBSA generic Watchdog(s).\n", gwdt_count);
+
+	return ret;
+}
+
+device_initcall(gtdt_sbsa_gwdt_init);