| /* |
| * MCE event pool management in MCE context |
| * |
| * Copyright (C) 2015 Intel Corp. |
| * Author: Chen, Gong <gong.chen@linux.intel.com> |
| * |
| * This file is licensed under GPLv2. |
| */ |
| #include <linux/smp.h> |
| #include <linux/mm.h> |
| #include <linux/genalloc.h> |
| #include <linux/llist.h> |
| #include "mce-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. Use |
| * 2 pages to save MCE events for now (~80 MCE records at most). |
| */ |
| #define MCE_POOLSZ (2 * PAGE_SIZE) |
| |
| static struct gen_pool *mce_evt_pool; |
| static LLIST_HEAD(mce_event_llist); |
| static char gen_pool_buf[MCE_POOLSZ]; |
| |
| void mce_gen_pool_process(void) |
| { |
| struct llist_node *head; |
| struct mce_evt_llist *node; |
| struct mce *mce; |
| |
| head = llist_del_all(&mce_event_llist); |
| if (!head) |
| return; |
| |
| head = llist_reverse_order(head); |
| llist_for_each_entry(node, head, llnode) { |
| mce = &node->mce; |
| atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce); |
| gen_pool_free(mce_evt_pool, (unsigned long)node, sizeof(*node)); |
| } |
| } |
| |
| bool mce_gen_pool_empty(void) |
| { |
| return llist_empty(&mce_event_llist); |
| } |
| |
| int mce_gen_pool_add(struct mce *mce) |
| { |
| struct mce_evt_llist *node; |
| |
| if (!mce_evt_pool) |
| return -EINVAL; |
| |
| node = (void *)gen_pool_alloc(mce_evt_pool, sizeof(*node)); |
| if (!node) { |
| pr_warn_ratelimited("MCE records pool full!\n"); |
| return -ENOMEM; |
| } |
| |
| memcpy(&node->mce, mce, sizeof(*mce)); |
| llist_add(&node->llnode, &mce_event_llist); |
| |
| return 0; |
| } |
| |
| static int mce_gen_pool_create(void) |
| { |
| struct gen_pool *tmpp; |
| int ret = -ENOMEM; |
| |
| tmpp = gen_pool_create(ilog2(sizeof(struct mce_evt_llist)), -1); |
| if (!tmpp) |
| goto out; |
| |
| ret = gen_pool_add(tmpp, (unsigned long)gen_pool_buf, MCE_POOLSZ, -1); |
| if (ret) { |
| gen_pool_destroy(tmpp); |
| goto out; |
| } |
| |
| mce_evt_pool = tmpp; |
| |
| out: |
| return ret; |
| } |
| |
| int mce_gen_pool_init(void) |
| { |
| /* Just init mce_gen_pool once. */ |
| if (mce_evt_pool) |
| return 0; |
| |
| return mce_gen_pool_create(); |
| } |