kernel_common_drivers/drivers/memory_debug/main.c

// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
/*
 * Copyright (c) 2019 Amlogic, Inc. All rights reserved.
 */

//#define DEBUG
#include <linux/module.h>
#include <linux/device.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/types.h>
#include <linux/moduleparam.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/mm.h>
#include <linux/kasan.h>
#include <linux/kthread.h>
#include <linux/time.h>
#include <linux/delay.h>
#include <linux/amlogic/module_merge.h>
#include "main.h"
#include <linux/amlogic/aml_free_reserved.h>
#include <linux/amlogic/aml_cma.h>

unsigned long aml_free_reserved_area(void *start, void *end, int poison, const char *s)
{
	void *pos;
	unsigned long pages = 0;

	start = (void *)PAGE_ALIGN((unsigned long)start);
	end = (void *)((unsigned long)end & PAGE_MASK);
	for (pos = start; pos < end; pos += PAGE_SIZE, pages++) {
		struct page *page = virt_to_page(pos);
		void *direct_map_addr;

		/*
		 * 'direct_map_addr' might be different from 'pos'
		 * because some architectures' virt_to_page()
		 * work with aliases.  Getting the direct map
		 * address ensures that we get a _writeable_
		 * alias for the memset().
		 */
		direct_map_addr = page_address(page);
		/*
		 * Perform a kasan-unchecked memset() since this memory
		 * has not been initialized.
		 */
		direct_map_addr = kasan_reset_tag(direct_map_addr);
		if ((unsigned int)poison <= 0xFF)
			memset(direct_map_addr, poison, PAGE_SIZE);

		free_reserved_page(page);
	}

	if (pages && s)
		pr_info("Freeing %s memory: %ldK\n",
			s, pages << (PAGE_SHIFT - 10));

	return pages;
}
EXPORT_SYMBOL(aml_free_reserved_area);

#if IS_ENABLED(CONFIG_AMLOGIC_DEBUG_IOTRACE)
#include <linux/of_address.h>
#include <linux/of.h>
#include <linux/amlogic/aml_iotrace.h>
#if IS_ENABLED(CONFIG_AMLOGIC_DEBUG_IOTM)
#include <linux/amlogic/aml_iotm.h>
#endif
void free_iotrace_reserved_memory(void)
{
	int ret;
	struct resource res;
	struct device_node *node = NULL;

	node = of_find_node_by_path("/reserved-memory/linux,iotrace");
	if (!node)
		return;

	/* Do nothing if linux,iotrace status is disabled */
	if (!of_device_is_available(node))
		return;

	ret = of_address_to_resource(node, 0, &res);
	if (ret)
		return;

	// free reserved-memory if no need
	if (!ramoops_ftrace_en) {
#if IS_ENABLED(CONFIG_AMLOGIC_DEBUG_IOTM)
		unsigned int iotm_ddr_size = 0;

		/* exclude iotm_ddr_size in axi_mode. */
		if (iotm_en_ddr_size_get(&iotm_ddr_size) && iotm_monitor_mode_get() == 0)
			res.end = res.end - PAGE_ALIGN(iotm_ddr_size);
#endif
		aml_free_reserved_area(__va(res.start), __va(PAGE_ALIGN(res.end)), 0,
								"free_reserved");
		pr_debug("free iotrace reserved_memory\n");
	}
}
#endif

#define MAX_CMA_TASKS 8
struct task_struct *matched_cmatasks[MAX_CMA_TASKS];

static int get_current_cma_task_nice(void)
{
	if (matched_cmatasks[0])
		return task_nice(matched_cmatasks[0]);

	pr_err("can not find cma task thread.\n");

	return -EINVAL;
}

static int set_cma_task_nice(int nice)
{
	int cur_nice;
	int i = 0;

	cur_nice = get_current_cma_task_nice();
	if (cur_nice == -EINVAL || cur_nice == nice)
		return 0;

	for (i = 0; i < MAX_CMA_TASKS; i++) {
		if (matched_cmatasks[i])
			set_user_nice(matched_cmatasks[i], nice);
	}
	pr_info("renice cma task to %d\n", nice);

	return 0;
}

/*
 * level 0: nice = -17, default value
 * level 1: nice = -10
 * level 2: nice = 0
 */
int set_cma_task_priority_level(int level)
{
	int ret;
	int cma_task_level[] = {-17, -10, 0};

	if (level < 0 || level > 2) {
		pr_err("out of level range: [0-2]");
		return -EINVAL;
	}
	ret = set_cma_task_nice(cma_task_level[level]);

	return ret;
}
EXPORT_SYMBOL(set_cma_task_priority_level);

static int find_cma_task_hook(void *data)
{
	struct task_struct *tsk;
	int i = 0;
	char task_name[MAX_CMA_TASKS][20] = {0};

	for (i = 0; i < MAX_CMA_TASKS; i++)
		sprintf(task_name[i], "cma_task%d", i);

	while (1) {
		rcu_read_lock();
		for_each_process(tsk) {
			/* skip userspace task */
			if (tsk->mm)
				continue;

			for (i = 0; i < MAX_CMA_TASKS; i++) {
				if (matched_cmatasks[i])
					continue;
				if (!strncmp(tsk->comm, task_name[i], 9)) {
					matched_cmatasks[i] = tsk;
					break;
				}
			}
		}
		rcu_read_unlock();

		if (matched_cmatasks[0])
			break;

		msleep_interruptible(500);
	}

	return 0;
}

static int __init memory_main_init(void)
{
	pr_debug("### %s() start\n", __func__);
	call_sub_init(filecache_module_init);
	call_sub_init(aml_watch_pint_init);
	call_sub_init(aml_reg_init);
	call_sub_init(ddr_tool_init);
	call_sub_init(ramdump_init);
#if IS_ENABLED(CONFIG_AMLOGIC_DEBUG_IOTRACE)
	free_iotrace_reserved_memory();
#endif
	pr_debug("### %s() end\n", __func__);

	kthread_run(find_cma_task_hook, NULL, "find_cma_task");

	return 0;
}

static void __exit memory_main_exit(void)
{
	ramdump_uninit();
	ddr_tool_exit();
	aml_reg_exit();
	aml_watch_point_uninit();
	filecache_module_exit();
}

module_init(memory_main_init);
module_exit(memory_main_exit);
MODULE_LICENSE("GPL v2");