linux/arch/x86/kernel/cpu/mce/genpool.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * MCE event pool management in MCE context
 *
 * Copyright (C) 2015 Intel Corp.
 * Author: Chen, Gong <[email protected]>
 */
#include <linux/smp.h>
#include <linux/mm.h>
#include <linux/genalloc.h>
#include <linux/llist.h>
#include "internal.h"

/*
 * printk() is not safe in MCE context. This is a lock-less memory allocator
 * used to save error information organized in a lock-less list.
 *
 * This memory pool is only to be used to save MCE records in MCE context.
 * MCE events are rare, so a fixed size memory pool should be enough.
 * Allocate on a sliding scale based on number of CPUs.
 */
#define MCE_MIN_ENTRIES …
#define MCE_PER_CPU …

static struct gen_pool *mce_evt_pool;
static LLIST_HEAD(mce_event_llist);

/*
 * Compare the record "t" with each of the records on list "l" to see if
 * an equivalent one is present in the list.
 */
static bool is_duplicate_mce_record(struct mce_evt_llist *t, struct mce_evt_llist *l)
{ … }

/*
 * The system has panicked - we'd like to peruse the list of MCE records
 * that have been queued, but not seen by anyone yet.  The list is in
 * reverse time order, so we need to reverse it. While doing that we can
 * also drop duplicate records (these were logged because some banks are
 * shared between cores or by all threads on a socket).
 */
struct llist_node *mce_gen_pool_prepare_records(void)
{ … }

void mce_gen_pool_process(struct work_struct *__unused)
{ … }

bool mce_gen_pool_empty(void)
{ … }

int mce_gen_pool_add(struct mce *mce)
{ … }

static int mce_gen_pool_create(void)
{ … }

int mce_gen_pool_init(void)
{ … }