// SPDX-License-Identifier: GPL-2.0-only
/*
 * Generic show_mem() implementation
 *
 * Copyright (C) 2008 Johannes Weiner <hannes@saeurebad.de>
 */

#include <linux/blkdev.h>
#include <linux/cma.h>
#include <linux/cpuset.h>
#include <linux/highmem.h>
#include <linux/hugetlb.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/swap.h>
#include <linux/vmstat.h>

#include "internal.h"
#include "swap.h"

atomic_long_t _totalram_pages __read_mostly;
EXPORT_SYMBOL(_totalram_pages);
unsigned long totalreserve_pages __read_mostly;
unsigned long totalcma_pages __read_mostly;

static inline void show_node(struct zone *zone)
{
        if (IS_ENABLED(CONFIG_NUMA))
                printk("Node %d ", zone_to_nid(zone));
}

long si_mem_available(void)
{
        long available;
        unsigned long pagecache;
        unsigned long wmark_low = 0;
        unsigned long reclaimable;
        struct zone *zone;

        for_each_zone(zone)
                wmark_low += low_wmark_pages(zone);

        /*
         * Estimate the amount of memory available for userspace allocations,
         * without causing swapping or OOM.
         */
        available = global_zone_page_state(NR_FREE_PAGES) - totalreserve_pages;

        /*
         * Not all the page cache can be freed, otherwise the system will
         * start swapping or thrashing. Assume at least half of the page
         * cache, or the low watermark worth of cache, needs to stay.
         */
        pagecache = global_node_page_state(NR_ACTIVE_FILE) +
                global_node_page_state(NR_INACTIVE_FILE);
        pagecache -= min(pagecache / 2, wmark_low);
        available += pagecache;

        /*
         * Part of the reclaimable slab and other kernel memory consists of
         * items that are in use, and cannot be freed. Cap this estimate at the
         * low watermark.
         */
        reclaimable = global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B) +
                global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE);
        reclaimable -= min(reclaimable / 2, wmark_low);
        available += reclaimable;

        if (available < 0)
                available = 0;
        return available;
}
EXPORT_SYMBOL_GPL(si_mem_available);

void si_meminfo(struct sysinfo *val)
{
        val->totalram = totalram_pages();
        val->sharedram = global_node_page_state(NR_SHMEM);
        val->freeram = global_zone_page_state(NR_FREE_PAGES);
        val->bufferram = nr_blockdev_pages();
        val->totalhigh = totalhigh_pages();
        val->freehigh = nr_free_highpages();
        val->mem_unit = PAGE_SIZE;
}

EXPORT_SYMBOL(si_meminfo);

#ifdef CONFIG_NUMA
void si_meminfo_node(struct sysinfo *val, int nid)
{
        int zone_type;          /* needs to be signed */
        unsigned long managed_pages = 0;
        unsigned long managed_highpages = 0;
        unsigned long free_highpages = 0;
        pg_data_t *pgdat = NODE_DATA(nid);

        for (zone_type = 0; zone_type < MAX_NR_ZONES; zone_type++) {
                struct zone *zone = &pgdat->node_zones[zone_type];
                managed_pages += zone_managed_pages(zone);
                if (is_highmem(zone)) {
                        managed_highpages += zone_managed_pages(zone);
                        free_highpages += zone_page_state(zone, NR_FREE_PAGES);
                }
        }

        val->totalram = managed_pages;
        val->sharedram = node_page_state(pgdat, NR_SHMEM);
        val->freeram = sum_zone_node_page_state(nid, NR_FREE_PAGES);
        val->totalhigh = managed_highpages;
        val->freehigh = free_highpages;
        val->mem_unit = PAGE_SIZE;
}
#endif

/*
 * Determine whether the node should be displayed or not, depending on whether
 * SHOW_MEM_FILTER_NODES was passed to show_free_areas().
 */
static bool show_mem_node_skip(unsigned int flags, int nid, nodemask_t *nodemask)
{
        if (!(flags & SHOW_MEM_FILTER_NODES))
                return false;

        /*
         * no node mask - aka implicit memory numa policy. Do not bother with
         * the synchronization - read_mems_allowed_begin - because we do not
         * have to be precise here.
         */
        if (!nodemask)
                nodemask = &cpuset_current_mems_allowed;

        return !node_isset(nid, *nodemask);
}

static void show_migration_types(unsigned char type)
{
        static const char types[MIGRATE_TYPES] = {
                [MIGRATE_UNMOVABLE]     = 'U',
                [MIGRATE_MOVABLE]       = 'M',
                [MIGRATE_RECLAIMABLE]   = 'E',
                [MIGRATE_HIGHATOMIC]    = 'H',
#ifdef CONFIG_CMA
                [MIGRATE_CMA]           = 'C',
#endif
#ifdef CONFIG_MEMORY_ISOLATION
                [MIGRATE_ISOLATE]       = 'I',
#endif
        };
        char tmp[MIGRATE_TYPES + 1];
        char *p = tmp;
        int i;

        for (i = 0; i < MIGRATE_TYPES; i++) {
                if (type & (1 << i))
                        *p++ = types[i];
        }

        *p = '\0';
        printk(KERN_CONT "(%s) ", tmp);
}

static bool node_has_managed_zones(pg_data_t *pgdat, int max_zone_idx)
{
        int zone_idx;
        for (zone_idx = 0; zone_idx <= max_zone_idx; zone_idx++)
                if (zone_managed_pages(pgdat->node_zones + zone_idx))
                        return true;
        return false;
}

/*
 * Show free area list (used inside shift_scroll-lock stuff)
 * We also calculate the percentage fragmentation. We do this by counting the
 * memory on each free list with the exception of the first item on the list.
 *
 * Bits in @filter:
 * SHOW_MEM_FILTER_NODES: suppress nodes that are not allowed by current's
 *   cpuset.
 */
static void show_free_areas(unsigned int filter, nodemask_t *nodemask, int max_zone_idx)
{
        unsigned long free_pcp = 0;
        int cpu, nid;
        struct zone *zone;
        pg_data_t *pgdat;

        for_each_populated_zone(zone) {
                if (zone_idx(zone) > max_zone_idx)
                        continue;
                if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
                        continue;

                for_each_online_cpu(cpu)
                        free_pcp += per_cpu_ptr(zone->per_cpu_pageset, cpu)->count;
        }

        printk("active_anon:%lu inactive_anon:%lu isolated_anon:%lu\n"
                " active_file:%lu inactive_file:%lu isolated_file:%lu\n"
                " unevictable:%lu dirty:%lu writeback:%lu\n"
                " slab_reclaimable:%lu slab_unreclaimable:%lu\n"
                " mapped:%lu shmem:%lu pagetables:%lu\n"
                " sec_pagetables:%lu bounce:%lu\n"
                " kernel_misc_reclaimable:%lu\n"
                " free:%lu free_pcp:%lu free_cma:%lu\n",
                global_node_page_state(NR_ACTIVE_ANON),
                global_node_page_state(NR_INACTIVE_ANON),
                global_node_page_state(NR_ISOLATED_ANON),
                global_node_page_state(NR_ACTIVE_FILE),
                global_node_page_state(NR_INACTIVE_FILE),
                global_node_page_state(NR_ISOLATED_FILE),
                global_node_page_state(NR_UNEVICTABLE),
                global_node_page_state(NR_FILE_DIRTY),
                global_node_page_state(NR_WRITEBACK),
                global_node_page_state_pages(NR_SLAB_RECLAIMABLE_B),
                global_node_page_state_pages(NR_SLAB_UNRECLAIMABLE_B),
                global_node_page_state(NR_FILE_MAPPED),
                global_node_page_state(NR_SHMEM),
                global_node_page_state(NR_PAGETABLE),
                global_node_page_state(NR_SECONDARY_PAGETABLE),
                0UL,
                global_node_page_state(NR_KERNEL_MISC_RECLAIMABLE),
                global_zone_page_state(NR_FREE_PAGES),
                free_pcp,
                global_zone_page_state(NR_FREE_CMA_PAGES));

        for_each_online_pgdat(pgdat) {
                if (show_mem_node_skip(filter, pgdat->node_id, nodemask))
                        continue;
                if (!node_has_managed_zones(pgdat, max_zone_idx))
                        continue;

                printk("Node %d"
                        " active_anon:%lukB"
                        " inactive_anon:%lukB"
                        " active_file:%lukB"
                        " inactive_file:%lukB"
                        " unevictable:%lukB"
                        " isolated(anon):%lukB"
                        " isolated(file):%lukB"
                        " mapped:%lukB"
                        " dirty:%lukB"
                        " writeback:%lukB"
                        " shmem:%lukB"
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
                        " shmem_thp:%lukB"
                        " shmem_pmdmapped:%lukB"
                        " anon_thp:%lukB"
#endif
                        " kernel_stack:%lukB"
#ifdef CONFIG_SHADOW_CALL_STACK
                        " shadow_call_stack:%lukB"
#endif
                        " pagetables:%lukB"
                        " sec_pagetables:%lukB"
                        " all_unreclaimable? %s"
                        " Balloon:%lukB"
                        "\n",
                        pgdat->node_id,
                        K(node_page_state(pgdat, NR_ACTIVE_ANON)),
                        K(node_page_state(pgdat, NR_INACTIVE_ANON)),
                        K(node_page_state(pgdat, NR_ACTIVE_FILE)),
                        K(node_page_state(pgdat, NR_INACTIVE_FILE)),
                        K(node_page_state(pgdat, NR_UNEVICTABLE)),
                        K(node_page_state(pgdat, NR_ISOLATED_ANON)),
                        K(node_page_state(pgdat, NR_ISOLATED_FILE)),
                        K(node_page_state(pgdat, NR_FILE_MAPPED)),
                        K(node_page_state(pgdat, NR_FILE_DIRTY)),
                        K(node_page_state(pgdat, NR_WRITEBACK)),
                        K(node_page_state(pgdat, NR_SHMEM)),
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
                        K(node_page_state(pgdat, NR_SHMEM_THPS)),
                        K(node_page_state(pgdat, NR_SHMEM_PMDMAPPED)),
                        K(node_page_state(pgdat, NR_ANON_THPS)),
#endif
                        node_page_state(pgdat, NR_KERNEL_STACK_KB),
#ifdef CONFIG_SHADOW_CALL_STACK
                        node_page_state(pgdat, NR_KERNEL_SCS_KB),
#endif
                        K(node_page_state(pgdat, NR_PAGETABLE)),
                        K(node_page_state(pgdat, NR_SECONDARY_PAGETABLE)),
                        str_yes_no(kswapd_test_hopeless(pgdat)),
                        K(node_page_state(pgdat, NR_BALLOON_PAGES)));
        }

        for_each_populated_zone(zone) {
                int i;

                if (zone_idx(zone) > max_zone_idx)
                        continue;
                if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
                        continue;

                free_pcp = 0;
                for_each_online_cpu(cpu)
                        free_pcp += per_cpu_ptr(zone->per_cpu_pageset, cpu)->count;

                show_node(zone);
                printk(KERN_CONT
                        "%s"
                        " free:%lukB"
                        " boost:%lukB"
                        " min:%lukB"
                        " low:%lukB"
                        " high:%lukB"
                        " reserved_highatomic:%luKB"
                        " free_highatomic:%luKB"
                        " active_anon:%lukB"
                        " inactive_anon:%lukB"
                        " active_file:%lukB"
                        " inactive_file:%lukB"
                        " unevictable:%lukB"
                        " writepending:%lukB"
                        " zspages:%lukB"
                        " present:%lukB"
                        " managed:%lukB"
                        " mlocked:%lukB"
                        " bounce:%lukB"
                        " free_pcp:%lukB"
                        " local_pcp:%ukB"
                        " free_cma:%lukB"
                        "\n",
                        zone->name,
                        K(zone_page_state(zone, NR_FREE_PAGES)),
                        K(zone->watermark_boost),
                        K(min_wmark_pages(zone)),
                        K(low_wmark_pages(zone)),
                        K(high_wmark_pages(zone)),
                        K(zone->nr_reserved_highatomic),
                        K(zone->nr_free_highatomic),
                        K(zone_page_state(zone, NR_ZONE_ACTIVE_ANON)),
                        K(zone_page_state(zone, NR_ZONE_INACTIVE_ANON)),
                        K(zone_page_state(zone, NR_ZONE_ACTIVE_FILE)),
                        K(zone_page_state(zone, NR_ZONE_INACTIVE_FILE)),
                        K(zone_page_state(zone, NR_ZONE_UNEVICTABLE)),
                        K(zone_page_state(zone, NR_ZONE_WRITE_PENDING)),
#if IS_ENABLED(CONFIG_ZSMALLOC)
                        K(zone_page_state(zone, NR_ZSPAGES)),
#else
                        0UL,
#endif
                        K(zone->present_pages),
                        K(zone_managed_pages(zone)),
                        K(zone_page_state(zone, NR_MLOCK)),
                        0UL,
                        K(free_pcp),
                        K(this_cpu_read(zone->per_cpu_pageset->count)),
                        K(zone_page_state(zone, NR_FREE_CMA_PAGES)));
                printk("lowmem_reserve[]:");
                for (i = 0; i < MAX_NR_ZONES; i++)
                        printk(KERN_CONT " %ld", zone->lowmem_reserve[i]);
                printk(KERN_CONT "\n");
        }

        for_each_populated_zone(zone) {
                unsigned int order;
                unsigned long nr[NR_PAGE_ORDERS], flags, total = 0;
                unsigned char types[NR_PAGE_ORDERS];

                if (zone_idx(zone) > max_zone_idx)
                        continue;
                if (show_mem_node_skip(filter, zone_to_nid(zone), nodemask))
                        continue;
                show_node(zone);
                printk(KERN_CONT "%s: ", zone->name);

                spin_lock_irqsave(&zone->lock, flags);
                for (order = 0; order < NR_PAGE_ORDERS; order++) {
                        struct free_area *area = &zone->free_area[order];
                        int type;

                        nr[order] = area->nr_free;
                        total += nr[order] << order;

                        types[order] = 0;
                        for (type = 0; type < MIGRATE_TYPES; type++) {
                                if (!free_area_empty(area, type))
                                        types[order] |= 1 << type;
                        }
                }
                spin_unlock_irqrestore(&zone->lock, flags);
                for (order = 0; order < NR_PAGE_ORDERS; order++) {
                        printk(KERN_CONT "%lu*%lukB ",
                               nr[order], K(1UL) << order);
                        if (nr[order])
                                show_migration_types(types[order]);
                }
                printk(KERN_CONT "= %lukB\n", K(total));
        }

        for_each_online_node(nid) {
                if (show_mem_node_skip(filter, nid, nodemask))
                        continue;
                hugetlb_show_meminfo_node(nid);
        }

        printk("%ld total pagecache pages\n", global_node_page_state(NR_FILE_PAGES));

        show_swap_cache_info();
}

void __show_mem(unsigned int filter, nodemask_t *nodemask, int max_zone_idx)
{
        unsigned long total = 0, reserved = 0, highmem = 0;
        struct zone *zone;

        printk("Mem-Info:\n");
        show_free_areas(filter, nodemask, max_zone_idx);

        for_each_populated_zone(zone) {

                total += zone->present_pages;
                reserved += zone->present_pages - zone_managed_pages(zone);

                if (is_highmem(zone))
                        highmem += zone->present_pages;
        }

        printk("%lu pages RAM\n", total);
        printk("%lu pages HighMem/MovableOnly\n", highmem);
        printk("%lu pages reserved\n", reserved);
#ifdef CONFIG_CMA
        printk("%lu pages cma reserved\n", totalcma_pages);
#endif
#ifdef CONFIG_MEMORY_FAILURE
        printk("%lu pages hwpoisoned\n", atomic_long_read(&num_poisoned_pages));
#endif
#ifdef CONFIG_MEM_ALLOC_PROFILING
        static DEFINE_SPINLOCK(mem_alloc_profiling_spinlock);

        if (spin_trylock(&mem_alloc_profiling_spinlock)) {
                struct codetag_bytes tags[10];
                size_t i, nr;

                nr = alloc_tag_top_users(tags, ARRAY_SIZE(tags), false);
                if (nr) {
                        pr_notice("Memory allocations (profiling is currently turned %s):\n",
                                mem_alloc_profiling_enabled() ? "on" : "off");
                        for (i = 0; i < nr; i++) {
                                struct codetag *ct = tags[i].ct;
                                struct alloc_tag *tag = ct_to_alloc_tag(ct);
                                struct alloc_tag_counters counter = alloc_tag_read(tag);
                                char bytes[10];

                                string_get_size(counter.bytes, 1, STRING_UNITS_2, bytes, sizeof(bytes));

                                /* Same as alloc_tag_to_text() but w/o intermediate buffer */
                                if (ct->modname)
                                        pr_notice("%12s %8llu %s:%u [%s] func:%s\n",
                                                  bytes, counter.calls, ct->filename,
                                                  ct->lineno, ct->modname, ct->function);
                                else
                                        pr_notice("%12s %8llu %s:%u func:%s\n",
                                                  bytes, counter.calls, ct->filename,
                                                  ct->lineno, ct->function);
                        }
                }
                spin_unlock(&mem_alloc_profiling_spinlock);
        }
#endif
}