// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2022-2023, NVIDIA CORPORATION.  All rights reserved.

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/seq_file.h>
#include <linux/fs.h>
#include <linux/debugfs.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/memblock.h>
#include <asm/page.h>
#include "tegra_bootloader_debug.h"

static const char *module_name = "tegra_bootloader_debug";
static const char *dir_name = "tegra_bootloader";
static void __iomem *usc;

#ifdef CONFIG_DEBUG_FS
static const char *gr_file_mb1 = "gr_mb1";
static const char *gr_file_mb2 = "gr_mb2";
static const char *gr_file_cpu_bl = "gr_cpu_bl";
static const char *boot_cfg = "boot_cfg";
#endif

struct gr_address_value {
	unsigned int gr_address;
	unsigned int gr_value;
};

struct gr_header {
	uint32_t mb1_offset;
	uint32_t mb1_size;
	uint32_t mb2_offset;
	uint32_t mb2_size;
	uint32_t cpu_bl_offset;
	uint32_t cpu_bl_size;
};

enum gr_stage {
	enum_gr_mb1,
	enum_gr_mb2,
	enum_gr_cpu_bl,
};

struct spi_header {
	uint16_t crc;
	uint16_t crc_ack;
	uint16_t frame_len;
	struct {
		uint8_t id: 3;
		uint8_t version: 3;
		uint8_t reserved: 1;
		uint8_t has_ts: 1;
	} version;
} __packed;

struct spi_boot_header {
	struct spi_header header;
	bool rm_respond_evt: 1;
	uint8_t rm_respond_data: 4;
	uint8_t reserved1: 3;
};

struct spi_boot_rx_frame_full {
	struct spi_boot_header header;
	uint8_t data[8200 - sizeof(struct spi_boot_header)];
};

static spinlock_t tegra_bl_lock;
static struct kobject *boot_profiler_kobj;
static void *tegra_bl_mapped_prof_start;
static void *tegra_bl_mapped_prof_ro_start;
static bool is_privileged_vm;

#ifdef CONFIG_DEBUG_FS
static const uint32_t gr_mb1 = enum_gr_mb1;
static const uint32_t gr_mb2 = enum_gr_mb2;
static const uint32_t gr_cpu_bl = enum_gr_cpu_bl;

static int dbg_golden_register_show(struct seq_file *s, void *unused);
static int dbg_golden_register_open_mb1(struct inode *inode, struct file *file);
static int dbg_golden_register_open_mb2(struct inode *inode, struct file *file);
static int dbg_golden_register_open_cpu_bl(struct inode *inode, struct file *file);
static struct dentry *bl_debug_node;
static struct dentry *bl_debug_verify_reg_node;
static struct dentry *bl_debug_boot_cfg;
static void *tegra_bl_mapped_debug_data_start;
static int boot_cfg_show(struct seq_file *s, void *unused);
static int boot_cfg_open(struct inode *inode, struct file *file);
static void *tegra_bl_mapped_boot_cfg_start;

static const struct file_operations debug_gr_fops_mb1 = {
	.open		= dbg_golden_register_open_mb1,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};


static const struct file_operations debug_gr_fops_mb2 = {
	.open		= dbg_golden_register_open_mb2,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};


static const struct file_operations debug_gr_fops_cpu_bl = {
	.open		= dbg_golden_register_open_cpu_bl,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static const struct file_operations boot_cfg_fops = {
	.open		= boot_cfg_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};
#endif /* CONFIG_DEBUG_FS */

#define MAX_PROFILE_STRLEN	55
/* This address corresponds to T234
 * TBD - get this information from DT node
 */
#define TEGRA_US_COUNTER_REG	0x0C6B0000
/* Size is currently hardcoded to 64k
 * as QB is using the same size.
 */
#define SIZE_OF_FULL_CARVEOUT (64*1024)

struct profiler_record {
	char str[MAX_PROFILE_STRLEN + 1];
	uint64_t timestamp;
} __packed;

static void profiler_show_entries(void *addr, int size)
{
	struct profiler_record *profiler_data;
	int count = 0;
	int i = 0;
	int prof_data_section_valid = 0;

	profiler_data = (struct profiler_record *)addr;
	count = size / sizeof(struct profiler_record);
	i = -1;
	pr_info("\n");
	while (count--) {
		i++;
		if (!profiler_data[i].timestamp) {
			if (prof_data_section_valid) {
				pr_info("\n");
				prof_data_section_valid = 0;
			}
			continue;
		}
		pr_info("%-54s\t%16lld",
			profiler_data[i].str, profiler_data[i].timestamp);
		if (i > 0 && profiler_data[i - 1].timestamp) {
			pr_cont("\t%16lld",
			profiler_data[i].timestamp - profiler_data[i - 1].timestamp);
		}
		prof_data_section_valid = 1;
	}
}

static ssize_t profiler_show(struct kobject *kobj,
			struct kobj_attribute *attr,
			char *buf)
{
	if (is_privileged_vm) {
		if (!tegra_bl_mapped_prof_ro_start) {
			pr_err("%s\n", "Error mapping RO profiling data\n");
			return -EINVAL;
		}

		profiler_show_entries(tegra_bl_mapped_prof_ro_start, tegra_bl_prof_ro_size);
	} else {
		if (!tegra_bl_mapped_prof_start) {
			pr_err("%s\n", "Error mapping RW profiling data\n");
			return -EINVAL;
		}

		profiler_show_entries(tegra_bl_mapped_prof_start, tegra_bl_prof_size);
	}

	return 0;
}

static struct kobj_attribute profiler_attribute =
	__ATTR(profiler, 0400, profiler_show, NULL);

/**
 * tegra_bl_add_profiler_entry - add a new profiling point
 * @buf: string to add as a profiling marker
 * @len: length of the string
 *
 * Return: 0 on success or error code in case of failure.
 */
size_t tegra_bl_add_profiler_entry(const char *buf, size_t len)
{
	int count = 0;
	int i = 0;
	struct profiler_record *profiler_data;

	if (len > MAX_PROFILE_STRLEN) {
		pr_err("%s: Failed to add record, invalid length: %ld\n",
			module_name, len);
		return -EINVAL;
	}

	if (!tegra_bl_mapped_prof_start || !tegra_bl_prof_size) {
		pr_err("Error mapping profiling data\n");
		return -EINVAL;
	}

	spin_lock(&tegra_bl_lock);

	profiler_data = (struct profiler_record *)tegra_bl_mapped_prof_start;
	count = tegra_bl_prof_size / sizeof(struct profiler_record);
	while (i < count) {
		if (!profiler_data[i].timestamp)
			break;
		i++;
	}

	if (i == count) {
		pr_err("Error profiling data buffer full\n");
		spin_unlock(&tegra_bl_lock);
		return -ENOMEM;
	}

	profiler_data[i].timestamp = readl(usc);
	spin_unlock(&tegra_bl_lock);

	strncpy(profiler_data[i].str, buf, len);

	return 0;
}
EXPORT_SYMBOL(tegra_bl_add_profiler_entry);

static ssize_t add_profiler_record_store(struct kobject *kobj,
			struct kobj_attribute *attr,
			const char *buf, size_t len)
{
	if (tegra_bl_add_profiler_entry(buf, len))
		pr_err("Error adding profiler entry failed\n");

	return len;
}

static struct kobj_attribute add_profiler_record_attribute =
	__ATTR_WO(add_profiler_record);

#ifdef CONFIG_DEBUG_FS
static int dbg_golden_register_show(struct seq_file *s, void *unused)
{
	struct gr_header *golden_reg_header = (struct gr_header *)tegra_bl_mapped_debug_data_start;
	struct gr_address_value *gr_memory_dump;
	unsigned int gr_entries = 0;
	int i;

	switch (*(int *)(s->private)){
		case enum_gr_mb1:
			gr_entries = golden_reg_header->mb1_size / sizeof(struct gr_address_value);
			gr_memory_dump = (struct gr_address_value *)(golden_reg_header->mb1_offset +
					tegra_bl_mapped_debug_data_start + sizeof(struct gr_header));
			break;
		case enum_gr_mb2:
			gr_entries = golden_reg_header->mb2_size / sizeof(struct gr_address_value);
			gr_memory_dump = (struct gr_address_value *)(golden_reg_header->mb2_offset +
					tegra_bl_mapped_debug_data_start + sizeof(struct gr_header));
			break;
		case enum_gr_cpu_bl:
			gr_entries = golden_reg_header->cpu_bl_size / sizeof(struct gr_address_value);
			gr_memory_dump = (struct gr_address_value *)(golden_reg_header->cpu_bl_offset +
					tegra_bl_mapped_debug_data_start + sizeof(struct gr_header));
			break;
		default:
			seq_printf(s, "Eiiiirror mapping bootloader debug data%x \n",*(int *)(s->private));
			return 0;
	}
	if (!gr_entries || !tegra_bl_mapped_debug_data_start) {
		seq_puts(s, "Error mapping bootloader debug data\n");
		return 0;
	}

	for (i = 0; i < gr_entries; i++) {
		seq_printf(s, "{Address 0x%08x}, {Value 0x%08x}\n",
			gr_memory_dump->gr_address, gr_memory_dump->gr_value);

		gr_memory_dump++;
	}

	return 0;
}

static int dbg_golden_register_open_mb1(__attribute((unused))struct inode *inode, struct file *file)
{
	return single_open(file, dbg_golden_register_show, (void *)&gr_mb1);
}

static int dbg_golden_register_open_mb2( __attribute((unused))struct inode *inode, struct file *file)
{
	return single_open(file, dbg_golden_register_show, (void *)&gr_mb2);
}

static int dbg_golden_register_open_cpu_bl( __attribute((unused))struct inode *inode, struct file *file)
{
	return single_open(file, dbg_golden_register_show, (void *)&gr_cpu_bl);
}
#endif /* CONFIG_DEBUG_FS */

static int __init tegra_bootloader_debuginit(void)
{
	void __iomem *ptr_bl_prof_ro_carveout = NULL;
	void __iomem *ptr_bl_prof_carveout = NULL;
	int bl_debug_verify_file_entry;
#ifdef CONFIG_DEBUG_FS
	void __iomem *ptr_bl_debug_data_start = NULL;
	void __iomem *ptr_bl_boot_cfg_start = NULL;

	if (debugfs_initialized()) {
		bl_debug_node = debugfs_create_dir(dir_name, NULL);

		if (IS_ERR_OR_NULL(bl_debug_node)) {
			pr_err("%s: failed to create debugfs entries: %ld\n",
				module_name, PTR_ERR(bl_debug_node));
			goto out_err;
		}

		pr_info("%s: created %s directory\n", module_name, dir_name);

		bl_debug_verify_reg_node = debugfs_create_file(gr_file_mb1, S_IRUGO,
					bl_debug_node, NULL, &debug_gr_fops_mb1);

		if (IS_ERR_OR_NULL(bl_debug_verify_reg_node)) {
			pr_err("%s: failed to create debugfs entries: %ld\n",
				module_name, PTR_ERR(bl_debug_verify_reg_node));
			goto out_err;
		}

		bl_debug_verify_reg_node = debugfs_create_file(gr_file_mb2, S_IRUGO,
					bl_debug_node, NULL, &debug_gr_fops_mb2);

		if (IS_ERR_OR_NULL(bl_debug_verify_reg_node)) {
			pr_err("%s: failed to create debugfs entries: %ld\n",
				module_name, PTR_ERR(bl_debug_verify_reg_node));
			goto out_err;
		}

		bl_debug_verify_reg_node = debugfs_create_file(gr_file_cpu_bl, S_IRUGO,
					bl_debug_node, NULL, &debug_gr_fops_cpu_bl);

		if (IS_ERR_OR_NULL(bl_debug_verify_reg_node)) {
			pr_err("%s: failed to create debugfs entries: %ld\n",
				module_name, PTR_ERR(bl_debug_verify_reg_node));
			goto out_err;
		}

		tegra_bl_mapped_debug_data_start =
			phys_to_virt(tegra_bl_debug_data_start);
		if (tegra_bl_debug_data_start != 0
				&& !pfn_valid(__phys_to_pfn(tegra_bl_debug_data_start))) {
			ptr_bl_debug_data_start = ioremap(tegra_bl_debug_data_start,
					tegra_bl_debug_data_size);

			WARN_ON(!ptr_bl_debug_data_start);
			if (!ptr_bl_debug_data_start) {
				pr_err("%s: Failed to map tegra_bl_debug_data_start%08x\n",
				   __func__, (unsigned int)tegra_bl_debug_data_start);
				goto out_err;
			}

			pr_info("Remapped tegra_bl_debug_data_start(0x%llx)"
				" to address(0x%llx), size(0x%llx)\n",
				(u64)tegra_bl_debug_data_start,
				(__force u64)ptr_bl_debug_data_start,
				(u64)tegra_bl_debug_data_size);
			tegra_bl_mapped_debug_data_start = (__force void *)ptr_bl_debug_data_start;
		}

		/*
		 * The BCP can be optional, so ignore creating if variables are not set
		 */
		if (tegra_bl_bcp_start && tegra_bl_bcp_size) {
			bl_debug_boot_cfg = debugfs_create_file(boot_cfg, 0444,
				bl_debug_node, NULL, &boot_cfg_fops);
			if (IS_ERR_OR_NULL(bl_debug_boot_cfg)) {
				pr_err("%s: failed to create debugfs entries: %ld\n",
					__func__, PTR_ERR(bl_debug_boot_cfg));
				goto out_err;
			}

			tegra_bl_mapped_boot_cfg_start =
				phys_to_virt(tegra_bl_bcp_start);
			if (!pfn_valid(__phys_to_pfn(tegra_bl_bcp_start))) {
				ptr_bl_boot_cfg_start = ioremap(tegra_bl_bcp_start,
								tegra_bl_bcp_size);

				WARN_ON(!ptr_bl_boot_cfg_start);
				if (!ptr_bl_boot_cfg_start) {
					pr_err("%s: Failed to map tegra_bl_prof_start %08x\n",
						__func__,
						(unsigned int)tegra_bl_bcp_start);
					goto out_err;
				}
				tegra_bl_mapped_boot_cfg_start =
					(__force void *)ptr_bl_boot_cfg_start;
			}
		}
	}
#endif /* CONFIG_DEBUG_FS */
	boot_profiler_kobj = kobject_create_and_add(dir_name, kernel_kobj);
	if (IS_ERR_OR_NULL(boot_profiler_kobj)) {
		pr_err("%s: failed to create sysfs entries: %ld\n",
			module_name, PTR_ERR(boot_profiler_kobj));
		goto out_err;
	}

	bl_debug_verify_file_entry = sysfs_create_file(boot_profiler_kobj,
			&profiler_attribute.attr);
	if (bl_debug_verify_file_entry) {
		pr_err("%s: failed to create sysfs file : %d\n",
			module_name, bl_debug_verify_file_entry);
		goto out_err;
	}

	bl_debug_verify_file_entry = sysfs_create_file(boot_profiler_kobj,
			&add_profiler_record_attribute.attr);
	if (bl_debug_verify_file_entry) {
		pr_err("%s: failed to create sysfs file : %d\n",
			module_name, bl_debug_verify_file_entry);
		goto out_err;
	}

	if (tegra_bl_prof_start != 0 && tegra_bl_prof_size != 0 &&
			!pfn_valid(__phys_to_pfn(tegra_bl_prof_start))) {
		ptr_bl_prof_carveout = ioremap(tegra_bl_prof_start, tegra_bl_prof_size);
		if (!ptr_bl_prof_carveout) {
			pr_err("%s: failed to map tegra_bl_prof_start\n", __func__);
			goto out_err;
		}

		pr_info("Remapped tegra_bl_prof_start(0x%llx) "
			"to address 0x%llx, size(0x%llx)\n",
			(u64)tegra_bl_prof_start,
			(__force u64)ptr_bl_prof_carveout,
			(u64)tegra_bl_prof_size);

		tegra_bl_mapped_prof_start = (__force void *)ptr_bl_prof_carveout;
	}

	if (tegra_bl_prof_ro_start != 0 && tegra_bl_prof_ro_size != 0 &&
			!pfn_valid(__phys_to_pfn(tegra_bl_prof_ro_start))) {
		ptr_bl_prof_ro_carveout = ioremap(tegra_bl_prof_ro_start, tegra_bl_prof_ro_size);
		if (!ptr_bl_prof_ro_carveout) {
			pr_err("%s: failed to map tegra_bl_prof_ro_start\n", __func__);
			goto out_err;
		}

		pr_info("Remapped tegra_bl_prof_ro_start(0x%llx) "
			"to address 0x%llx, size(0x%llx)\n",
			(u64)tegra_bl_prof_ro_start,
			(__force u64)ptr_bl_prof_ro_carveout,
			(u64)tegra_bl_prof_ro_size);

		tegra_bl_mapped_prof_ro_start = (__force void *)ptr_bl_prof_ro_carveout;

		is_privileged_vm = true;
	} else {
		is_privileged_vm = false;
	}

	usc = ioremap(TEGRA_US_COUNTER_REG, 4);
	if (!usc) {
		pr_err("Failed to map TEGRA_US_COUNTER_REG\n");
		goto out_err;
	}

	spin_lock_init(&tegra_bl_lock);

	return 0;

out_err:
#ifdef CONFIG_DEBUG_FS
	if (!IS_ERR_OR_NULL(bl_debug_node))
		debugfs_remove_recursive(bl_debug_node);
	if (ptr_bl_debug_data_start)
		iounmap(ptr_bl_debug_data_start);
	if (ptr_bl_boot_cfg_start)
		iounmap(ptr_bl_boot_cfg_start);
#endif
	if (ptr_bl_prof_carveout)
		iounmap(ptr_bl_prof_carveout);
	if (ptr_bl_prof_ro_carveout)
		iounmap(ptr_bl_prof_ro_carveout);

	if (boot_profiler_kobj) {
		sysfs_remove_file(boot_profiler_kobj,
			&profiler_attribute.attr);
		sysfs_remove_file(boot_profiler_kobj,
			&add_profiler_record_attribute.attr);
		kobject_put(boot_profiler_kobj);
		boot_profiler_kobj = NULL;
	}

	return -ENODEV;
}

#ifdef CONFIG_DEBUG_FS
static int boot_cfg_show(struct seq_file *s, void *unused)
{
	uint8_t *data = tegra_bl_mapped_boot_cfg_start;
	struct spi_boot_rx_frame_full *spi_frame =
			tegra_bl_mapped_boot_cfg_start;
	uint32_t i;

	seq_puts(s, "\n Dumping Boot Configuration Protocol ");
	seq_printf(s, "0x%08x bytes @ 0x%08x\n",
			(unsigned int)tegra_bl_bcp_size,
			(unsigned int)tegra_bl_bcp_start);

	seq_puts(s, "\n SPI frame header\n");
	seq_printf(s, " CRC	  : 0x%02x\n",
			spi_frame->header.header.crc);
	seq_printf(s, " CRC ACK	  : 0x%02x\n",
			spi_frame->header.header.crc_ack);
	seq_printf(s, " Frame len	: 0x%02x (%d)\n",
			spi_frame->header.header.frame_len,
			spi_frame->header.header.frame_len);
	seq_printf(s, " Protocol ID  : 0x%01x\n",
			spi_frame->header.header.version.id);
	seq_printf(s, " Version	  : 0x%01x\n",
			spi_frame->header.header.version.version);
	seq_printf(s, " Has ts	: 0x%01x\n",
			spi_frame->header.header.version.has_ts);
	seq_printf(s, " Run mode evt: 0x%01x\n",
			spi_frame->header.rm_respond_evt);
	seq_printf(s, " Run mode	 : 0x%01x\n",
			spi_frame->header.rm_respond_data);

	for (i = 0; i < tegra_bl_bcp_size; i++) {
		if (i % 12 == 0)
			seq_printf(s, "\n %05d | ", i);

		seq_printf(s, "0x%02x ", data[i]);
	}
	return 0;
}

static int boot_cfg_open(struct inode *inode, struct file *file)
{
	return single_open(file, boot_cfg_show, &inode->i_private);
}
#endif /* CONFIG_DEBUG_FS */

static int __init tegra_bl_debuginit_module_init(void)
{
	return tegra_bootloader_debuginit();
}

static void __exit tegra_bl_debuginit_module_exit(void)
{
#ifdef CONFIG_DEBUG_FS
	if (!IS_ERR_OR_NULL(bl_debug_node))
		debugfs_remove_recursive(bl_debug_node);

	if (tegra_bl_mapped_debug_data_start)
		iounmap((void __iomem *)tegra_bl_mapped_debug_data_start);

	if (tegra_bl_mapped_boot_cfg_start)
		iounmap((void __iomem *)tegra_bl_mapped_boot_cfg_start);
#endif
	if (tegra_bl_mapped_prof_ro_start)
		iounmap((void __iomem *)tegra_bl_mapped_prof_ro_start);

	if (tegra_bl_mapped_prof_start)
		iounmap((void __iomem *)tegra_bl_mapped_prof_start);

	if (boot_profiler_kobj) {
		sysfs_remove_file(boot_profiler_kobj,
			&profiler_attribute.attr);
		sysfs_remove_file(boot_profiler_kobj,
			&add_profiler_record_attribute.attr);
		kobject_put(boot_profiler_kobj);
		boot_profiler_kobj = NULL;
	}

	if (usc)
		iounmap(usc);
}

module_init(tegra_bl_debuginit_module_init);
module_exit(tegra_bl_debuginit_module_exit);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Driver to enumerate bootloader's debug data");
MODULE_AUTHOR("Mohit Dhingra <mdhingra@nvidia.com>");