android_kernel_xiaomi_sm7250/drivers/soc/qcom/mem-offline.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
 */

#include <linux/memory.h>
#include <linux/module.h>
#include <linux/memblock.h>
#include <linux/mmzone.h>
#include <linux/ktime.h>
#include <linux/of.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <linux/kobject.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/bootmem.h>
#include <linux/mailbox_client.h>
#include <linux/mailbox/qmp.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <soc/qcom/rpm-smd.h>

#define RPM_DDR_REQ 0x726464
#define AOP_MSG_ADDR_MASK		0xffffffff
#define AOP_MSG_ADDR_HIGH_SHIFT		32
#define MAX_LEN				96

static unsigned long start_section_nr, end_section_nr;
static struct kobject *kobj;
static unsigned int offline_granule, sections_per_block;
static bool is_rpm_controller;
#define MODULE_CLASS_NAME	"mem-offline"
#define BUF_LEN			100

struct section_stat {
	unsigned long success_count;
	unsigned long fail_count;
	unsigned long avg_time;
	unsigned long best_time;
	unsigned long worst_time;
	unsigned long total_time;
	unsigned long last_recorded_time;
};

enum memory_states {
	MEMORY_ONLINE,
	MEMORY_OFFLINE,
	MAX_STATE,
};

static enum memory_states *mem_sec_state;

static struct mem_offline_mailbox {
	struct mbox_client cl;
	struct mbox_chan *mbox;
} mailbox;

struct memory_refresh_request {
	u64 start;	/* Lower bit signifies action
			 * 0 - disable self-refresh
			 * 1 - enable self-refresh
			 * upper bits are for base address
			 */
	u32 size;	/* size of memory region */
};

static struct section_stat *mem_info;

static void clear_pgtable_mapping(phys_addr_t start, phys_addr_t end)
{
	unsigned long size = end - start;
	unsigned long virt = (unsigned long)phys_to_virt(start);
	unsigned long addr_end = virt + size;
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;

	pgd = pgd_offset_k(virt);

	while (virt < addr_end) {

		/* Check if we have PUD section mapping */
		pud = pud_offset(pgd, virt);
		if (pud_sect(*pud)) {
			pud_clear(pud);
			virt += PUD_SIZE;
			continue;
		}

		/* Check if we have PMD section mapping */
		pmd = pmd_offset(pud, virt);
		if (pmd_sect(*pmd)) {
			pmd_clear(pmd);
			virt += PMD_SIZE;
			continue;
		}

		/* Clear mapping for page entry */
		set_memory_valid(virt, 1, (int)false);
		virt += PAGE_SIZE;
	}

	virt = (unsigned long)phys_to_virt(start);
	flush_tlb_kernel_range(virt, addr_end);
}
void record_stat(unsigned long sec, ktime_t delay, int mode)
{
	unsigned int total_sec = end_section_nr - start_section_nr + 1;
	unsigned int blk_nr = (sec - start_section_nr + mode * total_sec) /
				sections_per_block;

	if (sec > end_section_nr)
		return;

	if (delay < mem_info[blk_nr].best_time || !mem_info[blk_nr].best_time)
		mem_info[blk_nr].best_time = delay;

	if (delay > mem_info[blk_nr].worst_time)
		mem_info[blk_nr].worst_time = delay;

	++mem_info[blk_nr].success_count;
	if (mem_info[blk_nr].fail_count)
		--mem_info[blk_nr].fail_count;

	mem_info[blk_nr].total_time += delay;

	mem_info[blk_nr].avg_time =
		mem_info[blk_nr].total_time / mem_info[blk_nr].success_count;

	mem_info[blk_nr].last_recorded_time = delay;
}

static int mem_region_refresh_control(unsigned long pfn,
				      unsigned long nr_pages,
				      bool enable)
{
	struct memory_refresh_request mem_req;
	struct msm_rpm_kvp rpm_kvp;

	mem_req.start = enable;
	mem_req.start |= pfn << PAGE_SHIFT;
	mem_req.size = nr_pages * PAGE_SIZE;

	rpm_kvp.key = RPM_DDR_REQ;
	rpm_kvp.data = (void *)&mem_req;
	rpm_kvp.length = sizeof(mem_req);

	return msm_rpm_send_message(MSM_RPM_CTX_ACTIVE_SET, RPM_DDR_REQ, 0,
				    &rpm_kvp, 1);
}

static int aop_send_msg(unsigned long addr, bool online)
{
	struct qmp_pkt pkt;
	char mbox_msg[MAX_LEN];
	unsigned long addr_low, addr_high;

	addr_low = addr & AOP_MSG_ADDR_MASK;
	addr_high = (addr >> AOP_MSG_ADDR_HIGH_SHIFT) & AOP_MSG_ADDR_MASK;

	snprintf(mbox_msg, MAX_LEN,
		 "{class: ddr, event: pasr, addr_hi: 0x%08lx, addr_lo: 0x%08lx, refresh: %s}",
		 addr_high, addr_low, online ? "on" : "off");

	pkt.size = MAX_LEN;
	pkt.data = mbox_msg;
	return (mbox_send_message(mailbox.mbox, &pkt) < 0);
}

/*
 * When offline_granule >= memory block size, this returns the number of
 * sections in a offlineable segment.
 * When offline_granule < memory block size, returns the sections_per_block.
 */
static unsigned long get_rounded_sections_per_segment(void)
{

	return max(((offline_granule * SZ_1M) / memory_block_size_bytes()) *
		     sections_per_block,
		     (unsigned long)sections_per_block);
}

static int send_msg(struct memory_notify *mn, bool online, int count)
{
	unsigned long segment_size = offline_granule * SZ_1M;
	unsigned long start, base_sec_nr, sec_nr, sections_per_segment;
	int ret, idx, i;

	sections_per_segment = get_rounded_sections_per_segment();
	sec_nr = pfn_to_section_nr(SECTION_ALIGN_DOWN(mn->start_pfn));
	idx = (sec_nr - start_section_nr) / sections_per_segment;
	base_sec_nr = start_section_nr + (idx * sections_per_segment);
	start = section_nr_to_pfn(base_sec_nr);

	for (i = 0; i < count; ++i) {
		if (is_rpm_controller)
			ret = mem_region_refresh_control(start,
						 segment_size >> PAGE_SHIFT,
						 online);
		else
			ret = aop_send_msg(__pfn_to_phys(start), online);

		if (ret) {
			pr_err("PASR: %s %s request addr:0x%llx failed\n",
			       is_rpm_controller ? "RPM" : "AOP",
			       online ? "online" : "offline",
			       __pfn_to_phys(start));
			goto undo;
		}

		start = __phys_to_pfn(__pfn_to_phys(start) + segment_size);
	}

	return 0;
undo:
	start = section_nr_to_pfn(base_sec_nr);
	while (i-- > 0) {
		int ret;

		if (is_rpm_controller)
			ret = mem_region_refresh_control(start,
						 segment_size >> PAGE_SHIFT,
						 !online);
		else
			ret = aop_send_msg(__pfn_to_phys(start), !online);

		if (ret)
			panic("Failed to completely online/offline a hotpluggable segment. A quasi state of memblock can cause randomn system failures.");
		start = __phys_to_pfn(__pfn_to_phys(start) + segment_size);
	}

	return ret;
}

static bool need_to_send_remote_request(struct memory_notify *mn,
				    enum memory_states request)
{
	int i, idx, cur_idx;
	int base_sec_nr, sec_nr;
	unsigned long sections_per_segment;

	sections_per_segment = get_rounded_sections_per_segment();
	sec_nr = pfn_to_section_nr(SECTION_ALIGN_DOWN(mn->start_pfn));
	idx = (sec_nr - start_section_nr) / sections_per_segment;
	cur_idx = (sec_nr - start_section_nr) / sections_per_block;
	base_sec_nr = start_section_nr + (idx * sections_per_segment);

	/*
	 * For MEM_OFFLINE, don't send the request if there are other online
	 * blocks in the segment.
	 * For MEM_ONLINE, don't send the request if there is already one
	 * online block in the segment.
	 */
	if (request == MEMORY_OFFLINE || request == MEMORY_ONLINE) {
		for (i = base_sec_nr;
		     i < (base_sec_nr + sections_per_segment);
		     i += sections_per_block) {
			idx = (i - start_section_nr) / sections_per_block;
			/* current operating block */
			if (idx == cur_idx)
				continue;
			if (mem_sec_state[idx] == MEMORY_ONLINE)
				goto out;
		}
		return true;
	}
out:
	return false;
}

/*
 * This returns the number of hotpluggable segments in a memory block.
 */
static int get_num_memblock_hotplug_segments(void)
{
	unsigned long segment_size = offline_granule * SZ_1M;
	unsigned long block_size = memory_block_size_bytes();

	if (segment_size < block_size) {
		if (block_size % segment_size) {
			pr_warn("PASR is unusable. Offline granule size should be in multiples for memory_block_size_bytes.\n");
			return 0;
		}
		return block_size / segment_size;
	}

	return 1;
}

static int mem_change_refresh_state(struct memory_notify *mn,
				    enum memory_states state)
{
	int start = SECTION_ALIGN_DOWN(mn->start_pfn);
	unsigned long sec_nr = pfn_to_section_nr(start);
	bool online = (state == MEMORY_ONLINE) ? true : false;
	unsigned long idx = (sec_nr - start_section_nr) / sections_per_block;
	int ret, count;

	if (mem_sec_state[idx] == state) {
		/* we shouldn't be getting this request */
		pr_warn("mem-offline: state of mem%d block already in %s state. Ignoring refresh state change request\n",
				sec_nr, online ? "online" : "offline");
		return 0;
	}

	count = get_num_memblock_hotplug_segments();
	if (!count)
		return -EINVAL;

	if (!need_to_send_remote_request(mn, state))
		goto out;

	ret = send_msg(mn, online, count);
	if (ret) {
		/* online failures are critical failures */
		if (online)
			BUG_ON(IS_ENABLED(CONFIG_BUG_ON_HW_MEM_ONLINE_FAIL));
		return -EINVAL;
	}
out:
	mem_sec_state[idx] = state;
	return 0;
}

static int mem_event_callback(struct notifier_block *self,
				unsigned long action, void *arg)
{
	struct memory_notify *mn = arg;
	unsigned long start, end, sec_nr;
	static ktime_t cur;
	ktime_t delay = 0;
	phys_addr_t start_addr, end_addr;
	unsigned int idx = end_section_nr - start_section_nr + 1;

	start = SECTION_ALIGN_DOWN(mn->start_pfn);
	end = SECTION_ALIGN_UP(mn->start_pfn + mn->nr_pages);

	if ((start != mn->start_pfn) || (end != mn->start_pfn + mn->nr_pages)) {
		WARN("mem-offline: %s pfn not aligned to section\n", __func__);
		pr_err("mem-offline: start pfn = %lu end pfn = %lu\n",
			mn->start_pfn, mn->start_pfn + mn->nr_pages);
		return -EINVAL;
	}

	start_addr = __pfn_to_phys(start);
	end_addr = __pfn_to_phys(end);
	sec_nr = pfn_to_section_nr(start);

	if (sec_nr > end_section_nr || sec_nr < start_section_nr) {
		if (action == MEM_ONLINE || action == MEM_OFFLINE)
			pr_info("mem-offline: %s mem%ld, but not our block. Not performing any action\n",
				action == MEM_ONLINE ? "Onlined" : "Offlined",
				sec_nr);
		return NOTIFY_OK;
	}
	switch (action) {
	case MEM_GOING_ONLINE:
		pr_debug("mem-offline: MEM_GOING_ONLINE : start = 0x%llx end = 0x%llx\n",
				start_addr, end_addr);
		++mem_info[(sec_nr - start_section_nr + MEMORY_ONLINE *
			   idx) / sections_per_block].fail_count;
		cur = ktime_get();

		if (mem_change_refresh_state(mn, MEMORY_ONLINE))
			return NOTIFY_BAD;

		if (!debug_pagealloc_enabled()) {
			/* Create kernel page-tables */
			create_pgtable_mapping(start_addr, end_addr);
		}

		break;
	case MEM_ONLINE:
		delay = ktime_ms_delta(ktime_get(), cur);
		record_stat(sec_nr, delay, MEMORY_ONLINE);
		cur = 0;
		pr_info("mem-offline: Onlined memory block mem%pK\n",
			(void *)sec_nr);
		break;
	case MEM_GOING_OFFLINE:
		pr_debug("mem-offline: MEM_GOING_OFFLINE : start = 0x%llx end = 0x%llx\n",
				start_addr, end_addr);
		++mem_info[(sec_nr - start_section_nr + MEMORY_OFFLINE *
			   idx) / sections_per_block].fail_count;
		cur = ktime_get();
		break;
	case MEM_OFFLINE:
		if (!debug_pagealloc_enabled()) {
			/* Clear kernel page-tables */
			clear_pgtable_mapping(start_addr, end_addr);
		}
		mem_change_refresh_state(mn, MEMORY_OFFLINE);
		/*
		 * Notifying that something went bad at this stage won't
		 * help since this is the last stage of memory hotplug.
		 */

		delay = ktime_ms_delta(ktime_get(), cur);
		record_stat(sec_nr, delay, MEMORY_OFFLINE);
		cur = 0;
		pr_info("mem-offline: Offlined memory block mem%pK\n",
			(void *)sec_nr);
		break;
	case MEM_CANCEL_ONLINE:
		pr_info("mem-offline: MEM_CANCEL_ONLINE: start = 0x%llx end = 0x%llx\n",
				start_addr, end_addr);
		mem_change_refresh_state(mn, MEMORY_OFFLINE);
		break;
	default:
		break;
	}
	return NOTIFY_OK;
}

static int mem_online_remaining_blocks(void)
{
	unsigned long memblock_end_pfn = __phys_to_pfn(memblock_end_of_DRAM());
	unsigned long ram_end_pfn = __phys_to_pfn(bootloader_memory_limit - 1);
	unsigned long block_size, memblock, pfn;
	unsigned int nid;
	phys_addr_t phys_addr;
	int fail = 0;

	block_size = memory_block_size_bytes();
	sections_per_block = block_size / MIN_MEMORY_BLOCK_SIZE;

	start_section_nr = pfn_to_section_nr(memblock_end_pfn);
	end_section_nr = pfn_to_section_nr(ram_end_pfn);

	if (memblock_end_of_DRAM() >= bootloader_memory_limit) {
		pr_info("mem-offline: System booted with no zone movable memory blocks. Cannot perform memory offlining\n");
		return -EINVAL;
	}
	for (memblock = start_section_nr; memblock <= end_section_nr;
			memblock += sections_per_block) {
		pfn = section_nr_to_pfn(memblock);
		phys_addr = __pfn_to_phys(pfn);

		if (phys_addr & (((PAGES_PER_SECTION * sections_per_block)
					<< PAGE_SHIFT) - 1)) {
			fail = 1;
			pr_warn("mem-offline: PFN of mem%lu block not aligned to section start. Not adding this memory block\n",
								memblock);
			continue;
		}
		nid = memory_add_physaddr_to_nid(phys_addr);
		if (add_memory(nid, phys_addr,
				 MIN_MEMORY_BLOCK_SIZE * sections_per_block)) {
			pr_warn("mem-offline: Adding memory block mem%lu failed\n",
								memblock);
			fail = 1;
		}
	}

	max_pfn = PFN_DOWN(memblock_end_of_DRAM());
	return fail;
}

static ssize_t show_mem_offline_granule(struct kobject *kobj,
				struct kobj_attribute *attr, char *buf)
{
	return snprintf(buf, BUF_LEN, "%lu\n", (unsigned long)offline_granule *
									SZ_1M);
}

static ssize_t show_mem_perf_stats(struct kobject *kobj,
				struct kobj_attribute *attr, char *buf)
{

	unsigned int blk_start = start_section_nr / sections_per_block;
	unsigned int blk_end = end_section_nr / sections_per_block;
	unsigned int idx = blk_end - blk_start + 1;
	unsigned int char_count = 0;
	unsigned int i, j;

	for (j = 0; j < MAX_STATE; j++) {
		char_count += snprintf(buf + char_count,  BUF_LEN,
			"\n\t%s\n\t\t\t", j == 0 ? "ONLINE" : "OFFLINE");
		for (i = blk_start; i <= blk_end; i++)
			char_count += snprintf(buf + char_count, BUF_LEN,
							"%s%d\t\t", "mem", i);
		char_count += snprintf(buf + char_count, BUF_LEN, "\n");
		char_count += snprintf(buf + char_count, BUF_LEN,
							"\tLast recd time:\t");
		for (i = 0; i <= blk_end - blk_start; i++)
			char_count += snprintf(buf + char_count, BUF_LEN,
			     "%lums\t\t", mem_info[i+j*idx].last_recorded_time);
		char_count += snprintf(buf + char_count, BUF_LEN, "\n");
		char_count += snprintf(buf + char_count, BUF_LEN,
							"\tAvg time:\t");
		for (i = 0; i <= blk_end - blk_start; i++)
			char_count += snprintf(buf + char_count, BUF_LEN,
				"%lums\t\t", mem_info[i+j*idx].avg_time);
		char_count += snprintf(buf + char_count, BUF_LEN, "\n");
		char_count += snprintf(buf + char_count, BUF_LEN,
							"\tBest time:\t");
		for (i = 0; i <= blk_end - blk_start; i++)
			char_count += snprintf(buf + char_count, BUF_LEN,
				"%lums\t\t", mem_info[i+j*idx].best_time);
		char_count += snprintf(buf + char_count, BUF_LEN, "\n");
		char_count += snprintf(buf + char_count, BUF_LEN,
							"\tWorst time:\t");
		for (i = 0; i <= blk_end - blk_start; i++)
			char_count += snprintf(buf + char_count, BUF_LEN,
				"%lums\t\t", mem_info[i+j*idx].worst_time);
		char_count += snprintf(buf + char_count, BUF_LEN, "\n");
		char_count += snprintf(buf + char_count, BUF_LEN,
							"\tSuccess count:\t");
		for (i = 0; i <= blk_end - blk_start; i++)
			char_count += snprintf(buf + char_count, BUF_LEN,
				"%lu\t\t", mem_info[i+j*idx].success_count);
		char_count += snprintf(buf + char_count, BUF_LEN, "\n");
		char_count += snprintf(buf + char_count, BUF_LEN,
							"\tFail count:\t");
		for (i = 0; i <= blk_end - blk_start; i++)
			char_count += snprintf(buf + char_count, BUF_LEN,
				"%lu\t\t", mem_info[i+j*idx].fail_count);
		char_count += snprintf(buf + char_count, BUF_LEN, "\n");
	}
	return char_count;
}

static struct kobj_attribute perf_stats_attr =
		__ATTR(perf_stats, 0444, show_mem_perf_stats, NULL);

static struct kobj_attribute offline_granule_attr =
		__ATTR(offline_granule, 0444, show_mem_offline_granule, NULL);

static struct attribute *mem_root_attrs[] = {
		&perf_stats_attr.attr,
		&offline_granule_attr.attr,
		NULL,
};

static struct attribute_group mem_attr_group = {
	.attrs = mem_root_attrs,
};

static int mem_sysfs_init(void)
{
	if (start_section_nr == end_section_nr)
		return -EINVAL;

	kobj = kobject_create_and_add(MODULE_CLASS_NAME, kernel_kobj);
	if (!kobj)
		return -ENOMEM;

	if (sysfs_create_group(kobj, &mem_attr_group))
		kobject_put(kobj);

	return 0;
}

static int mem_parse_dt(struct platform_device *pdev)
{
	const unsigned int *val;
	struct device_node *node = pdev->dev.of_node;

	val = of_get_property(node, "granule", NULL);
	if (!val) {
		pr_err("mem-offine: granule property not found in DT\n");
		return -EINVAL;
	}
	if (!*val) {
		pr_err("mem-offine: invalid granule property\n");
		return -EINVAL;
	}
	offline_granule = be32_to_cpup(val);
	if (!offline_granule || (offline_granule & (offline_granule - 1)) ||
	    ((offline_granule * SZ_1M < MIN_MEMORY_BLOCK_SIZE) &&
	     (MIN_MEMORY_BLOCK_SIZE % (offline_granule * SZ_1M)))) {
		pr_err("mem-offine: invalid granule property\n");
		return -EINVAL;
	}

	if (!of_find_property(node, "mboxes", NULL)) {
		is_rpm_controller = true;
		return 0;
	}

	mailbox.cl.dev = &pdev->dev;
	mailbox.cl.tx_block = true;
	mailbox.cl.tx_tout = 1000;
	mailbox.cl.knows_txdone = false;

	mailbox.mbox = mbox_request_channel(&mailbox.cl, 0);
	if (IS_ERR(mailbox.mbox)) {
		if (PTR_ERR(mailbox.mbox) != -EPROBE_DEFER)
			pr_err("mem-offline: failed to get mailbox channel %pK %ld\n",
				mailbox.mbox, PTR_ERR(mailbox.mbox));
		return PTR_ERR(mailbox.mbox);
	}

	return 0;
}

static struct notifier_block hotplug_memory_callback_nb = {
	.notifier_call = mem_event_callback,
	.priority = 0,
};

static int mem_offline_driver_probe(struct platform_device *pdev)
{
	unsigned int total_blks;
	int ret, i;

	ret = mem_parse_dt(pdev);
	if (ret)
		return ret;

	ret = mem_online_remaining_blocks();
	if (ret < 0)
		return -ENODEV;

	if (ret > 0)
		pr_err("mem-offline: !!ERROR!! Auto onlining some memory blocks failed. System could run with less RAM\n");

	total_blks = (end_section_nr - start_section_nr + 1) /
			sections_per_block;
	mem_info = kcalloc(total_blks * MAX_STATE, sizeof(*mem_info),
			   GFP_KERNEL);
	if (!mem_info)
		return -ENOMEM;

	mem_sec_state = kcalloc(total_blks, sizeof(*mem_sec_state), GFP_KERNEL);
	if (!mem_sec_state) {
		ret = -ENOMEM;
		goto err_free_mem_info;
	}

	/* we assume that hardware state of mem blocks are online after boot */
	for (i = 0; i < total_blks; i++)
		mem_sec_state[i] = MEMORY_ONLINE;

	if (mem_sysfs_init()) {
		ret = -ENODEV;
		goto err_free_mem_sec_state;
	}

	if (register_hotmemory_notifier(&hotplug_memory_callback_nb)) {
		pr_err("mem-offline: Registering memory hotplug notifier failed\n");
		ret = -ENODEV;
		goto err_sysfs_remove_group;
	}
	pr_info("mem-offline: Added memory blocks ranging from mem%lu - mem%lu\n",
			start_section_nr, end_section_nr);

	return 0;

err_sysfs_remove_group:
	sysfs_remove_group(kobj, &mem_attr_group);
	kobject_put(kobj);
err_free_mem_sec_state:
	kfree(mem_sec_state);
err_free_mem_info:
	kfree(mem_info);
	return ret;
}

static const struct of_device_id mem_offline_match_table[] = {
	{.compatible = "qcom,mem-offline"},
	{}
};

static struct platform_driver mem_offline_driver = {
	.probe = mem_offline_driver_probe,
	.driver = {
		.name = "mem_offline",
		.of_match_table = mem_offline_match_table,
		.owner = THIS_MODULE,
	},
};

static int __init mem_module_init(void)
{
	return platform_driver_register(&mem_offline_driver);
}

subsys_initcall(mem_module_init);