19d5171a8SRashmica Gupta /* 29d5171a8SRashmica Gupta * Copyright (C) IBM Corporation, 2014, 2017 39d5171a8SRashmica Gupta * Anton Blanchard, Rashmica Gupta. 49d5171a8SRashmica Gupta * 59d5171a8SRashmica Gupta * This program is free software; you can redistribute it and/or modify 69d5171a8SRashmica Gupta * it under the terms of the GNU General Public License as published by 79d5171a8SRashmica Gupta * the Free Software Foundation; either version 2 of the License, or 89d5171a8SRashmica Gupta * (at your option) any later version. 99d5171a8SRashmica Gupta */ 109d5171a8SRashmica Gupta 119d5171a8SRashmica Gupta #define pr_fmt(fmt) "memtrace: " fmt 129d5171a8SRashmica Gupta 139d5171a8SRashmica Gupta #include <linux/bitops.h> 149d5171a8SRashmica Gupta #include <linux/string.h> 159d5171a8SRashmica Gupta #include <linux/memblock.h> 169d5171a8SRashmica Gupta #include <linux/init.h> 179d5171a8SRashmica Gupta #include <linux/moduleparam.h> 189d5171a8SRashmica Gupta #include <linux/fs.h> 199d5171a8SRashmica Gupta #include <linux/debugfs.h> 209d5171a8SRashmica Gupta #include <linux/slab.h> 219d5171a8SRashmica Gupta #include <linux/memory.h> 229d5171a8SRashmica Gupta #include <linux/memory_hotplug.h> 239d5171a8SRashmica Gupta #include <asm/machdep.h> 249d5171a8SRashmica Gupta #include <asm/debugfs.h> 259d5171a8SRashmica Gupta 269d5171a8SRashmica Gupta /* This enables us to keep track of the memory removed from each node. */ 279d5171a8SRashmica Gupta struct memtrace_entry { 289d5171a8SRashmica Gupta void *mem; 299d5171a8SRashmica Gupta u64 start; 309d5171a8SRashmica Gupta u64 size; 319d5171a8SRashmica Gupta u32 nid; 329d5171a8SRashmica Gupta struct dentry *dir; 339d5171a8SRashmica Gupta char name[16]; 349d5171a8SRashmica Gupta }; 359d5171a8SRashmica Gupta 369d5171a8SRashmica Gupta static u64 memtrace_size; 379d5171a8SRashmica Gupta 389d5171a8SRashmica Gupta static struct memtrace_entry *memtrace_array; 399d5171a8SRashmica Gupta static unsigned int memtrace_array_nr; 409d5171a8SRashmica Gupta 419d5171a8SRashmica Gupta 429d5171a8SRashmica Gupta static ssize_t memtrace_read(struct file *filp, char __user *ubuf, 439d5171a8SRashmica Gupta size_t count, loff_t *ppos) 449d5171a8SRashmica Gupta { 459d5171a8SRashmica Gupta struct memtrace_entry *ent = filp->private_data; 469d5171a8SRashmica Gupta 479d5171a8SRashmica Gupta return simple_read_from_buffer(ubuf, count, ppos, ent->mem, ent->size); 489d5171a8SRashmica Gupta } 499d5171a8SRashmica Gupta 509d5171a8SRashmica Gupta static const struct file_operations memtrace_fops = { 519d5171a8SRashmica Gupta .llseek = default_llseek, 529d5171a8SRashmica Gupta .read = memtrace_read, 539d5171a8SRashmica Gupta .open = simple_open, 549d5171a8SRashmica Gupta }; 559d5171a8SRashmica Gupta 569d5171a8SRashmica Gupta static int check_memblock_online(struct memory_block *mem, void *arg) 579d5171a8SRashmica Gupta { 589d5171a8SRashmica Gupta if (mem->state != MEM_ONLINE) 599d5171a8SRashmica Gupta return -1; 609d5171a8SRashmica Gupta 619d5171a8SRashmica Gupta return 0; 629d5171a8SRashmica Gupta } 639d5171a8SRashmica Gupta 649d5171a8SRashmica Gupta static int change_memblock_state(struct memory_block *mem, void *arg) 659d5171a8SRashmica Gupta { 669d5171a8SRashmica Gupta unsigned long state = (unsigned long)arg; 679d5171a8SRashmica Gupta 689d5171a8SRashmica Gupta mem->state = state; 699d5171a8SRashmica Gupta 709d5171a8SRashmica Gupta return 0; 719d5171a8SRashmica Gupta } 729d5171a8SRashmica Gupta 739d5171a8SRashmica Gupta static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) 749d5171a8SRashmica Gupta { 759d5171a8SRashmica Gupta u64 end_pfn = start_pfn + nr_pages - 1; 769d5171a8SRashmica Gupta 779d5171a8SRashmica Gupta if (walk_memory_range(start_pfn, end_pfn, NULL, 789d5171a8SRashmica Gupta check_memblock_online)) 799d5171a8SRashmica Gupta return false; 809d5171a8SRashmica Gupta 819d5171a8SRashmica Gupta walk_memory_range(start_pfn, end_pfn, (void *)MEM_GOING_OFFLINE, 829d5171a8SRashmica Gupta change_memblock_state); 839d5171a8SRashmica Gupta 849d5171a8SRashmica Gupta if (offline_pages(start_pfn, nr_pages)) { 859d5171a8SRashmica Gupta walk_memory_range(start_pfn, end_pfn, (void *)MEM_ONLINE, 869d5171a8SRashmica Gupta change_memblock_state); 879d5171a8SRashmica Gupta return false; 889d5171a8SRashmica Gupta } 899d5171a8SRashmica Gupta 909d5171a8SRashmica Gupta walk_memory_range(start_pfn, end_pfn, (void *)MEM_OFFLINE, 919d5171a8SRashmica Gupta change_memblock_state); 929d5171a8SRashmica Gupta 939d5171a8SRashmica Gupta lock_device_hotplug(); 949d5171a8SRashmica Gupta remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT); 959d5171a8SRashmica Gupta unlock_device_hotplug(); 969d5171a8SRashmica Gupta 979d5171a8SRashmica Gupta return true; 989d5171a8SRashmica Gupta } 999d5171a8SRashmica Gupta 1009d5171a8SRashmica Gupta static u64 memtrace_alloc_node(u32 nid, u64 size) 1019d5171a8SRashmica Gupta { 1029d5171a8SRashmica Gupta u64 start_pfn, end_pfn, nr_pages; 1039d5171a8SRashmica Gupta u64 base_pfn; 1049d5171a8SRashmica Gupta 1058ccb442dSMichael Ellerman if (!node_spanned_pages(nid)) 1069d5171a8SRashmica Gupta return 0; 1079d5171a8SRashmica Gupta 1089d5171a8SRashmica Gupta start_pfn = node_start_pfn(nid); 1099d5171a8SRashmica Gupta end_pfn = node_end_pfn(nid); 1109d5171a8SRashmica Gupta nr_pages = size >> PAGE_SHIFT; 1119d5171a8SRashmica Gupta 1129d5171a8SRashmica Gupta /* Trace memory needs to be aligned to the size */ 1139d5171a8SRashmica Gupta end_pfn = round_down(end_pfn - nr_pages, nr_pages); 1149d5171a8SRashmica Gupta 1159d5171a8SRashmica Gupta for (base_pfn = end_pfn; base_pfn > start_pfn; base_pfn -= nr_pages) { 1169d5171a8SRashmica Gupta if (memtrace_offline_pages(nid, base_pfn, nr_pages) == true) 1179d5171a8SRashmica Gupta return base_pfn << PAGE_SHIFT; 1189d5171a8SRashmica Gupta } 1199d5171a8SRashmica Gupta 1209d5171a8SRashmica Gupta return 0; 1219d5171a8SRashmica Gupta } 1229d5171a8SRashmica Gupta 1239d5171a8SRashmica Gupta static int memtrace_init_regions_runtime(u64 size) 1249d5171a8SRashmica Gupta { 1259d5171a8SRashmica Gupta u32 nid; 1269d5171a8SRashmica Gupta u64 m; 1279d5171a8SRashmica Gupta 1289d5171a8SRashmica Gupta memtrace_array = kcalloc(num_online_nodes(), 1299d5171a8SRashmica Gupta sizeof(struct memtrace_entry), GFP_KERNEL); 1309d5171a8SRashmica Gupta if (!memtrace_array) { 1319d5171a8SRashmica Gupta pr_err("Failed to allocate memtrace_array\n"); 1329d5171a8SRashmica Gupta return -EINVAL; 1339d5171a8SRashmica Gupta } 1349d5171a8SRashmica Gupta 1359d5171a8SRashmica Gupta for_each_online_node(nid) { 1369d5171a8SRashmica Gupta m = memtrace_alloc_node(nid, size); 1379d5171a8SRashmica Gupta 1389d5171a8SRashmica Gupta /* 1399d5171a8SRashmica Gupta * A node might not have any local memory, so warn but 1409d5171a8SRashmica Gupta * continue on. 1419d5171a8SRashmica Gupta */ 1429d5171a8SRashmica Gupta if (!m) { 1439d5171a8SRashmica Gupta pr_err("Failed to allocate trace memory on node %d\n", nid); 1449d5171a8SRashmica Gupta continue; 1459d5171a8SRashmica Gupta } 1469d5171a8SRashmica Gupta 1479d5171a8SRashmica Gupta pr_info("Allocated trace memory on node %d at 0x%016llx\n", nid, m); 1489d5171a8SRashmica Gupta 1499d5171a8SRashmica Gupta memtrace_array[memtrace_array_nr].start = m; 1509d5171a8SRashmica Gupta memtrace_array[memtrace_array_nr].size = size; 1519d5171a8SRashmica Gupta memtrace_array[memtrace_array_nr].nid = nid; 1529d5171a8SRashmica Gupta memtrace_array_nr++; 1539d5171a8SRashmica Gupta } 1549d5171a8SRashmica Gupta 1559d5171a8SRashmica Gupta return 0; 1569d5171a8SRashmica Gupta } 1579d5171a8SRashmica Gupta 1589d5171a8SRashmica Gupta static struct dentry *memtrace_debugfs_dir; 1599d5171a8SRashmica Gupta 1609d5171a8SRashmica Gupta static int memtrace_init_debugfs(void) 1619d5171a8SRashmica Gupta { 1629d5171a8SRashmica Gupta int ret = 0; 1639d5171a8SRashmica Gupta int i; 1649d5171a8SRashmica Gupta 1659d5171a8SRashmica Gupta for (i = 0; i < memtrace_array_nr; i++) { 1669d5171a8SRashmica Gupta struct dentry *dir; 1679d5171a8SRashmica Gupta struct memtrace_entry *ent = &memtrace_array[i]; 1689d5171a8SRashmica Gupta 1699d5171a8SRashmica Gupta ent->mem = ioremap(ent->start, ent->size); 1709d5171a8SRashmica Gupta /* Warn but continue on */ 1719d5171a8SRashmica Gupta if (!ent->mem) { 1729d5171a8SRashmica Gupta pr_err("Failed to map trace memory at 0x%llx\n", 1739d5171a8SRashmica Gupta ent->start); 1749d5171a8SRashmica Gupta ret = -1; 1759d5171a8SRashmica Gupta continue; 1769d5171a8SRashmica Gupta } 1779d5171a8SRashmica Gupta 1789d5171a8SRashmica Gupta snprintf(ent->name, 16, "%08x", ent->nid); 1799d5171a8SRashmica Gupta dir = debugfs_create_dir(ent->name, memtrace_debugfs_dir); 180d3da701dSRashmica Gupta if (!dir) { 181d3da701dSRashmica Gupta pr_err("Failed to create debugfs directory for node %d\n", 182d3da701dSRashmica Gupta ent->nid); 1839d5171a8SRashmica Gupta return -1; 184d3da701dSRashmica Gupta } 1859d5171a8SRashmica Gupta 1869d5171a8SRashmica Gupta ent->dir = dir; 1879d5171a8SRashmica Gupta debugfs_create_file("trace", 0400, dir, ent, &memtrace_fops); 1889d5171a8SRashmica Gupta debugfs_create_x64("start", 0400, dir, &ent->start); 1899d5171a8SRashmica Gupta debugfs_create_x64("size", 0400, dir, &ent->size); 1909d5171a8SRashmica Gupta } 1919d5171a8SRashmica Gupta 1929d5171a8SRashmica Gupta return ret; 1939d5171a8SRashmica Gupta } 1949d5171a8SRashmica Gupta 195d3da701dSRashmica Gupta static int online_mem_block(struct memory_block *mem, void *arg) 196d3da701dSRashmica Gupta { 197d3da701dSRashmica Gupta return device_online(&mem->dev); 198d3da701dSRashmica Gupta } 199d3da701dSRashmica Gupta 200d3da701dSRashmica Gupta /* 201d3da701dSRashmica Gupta * Iterate through the chunks of memory we have removed from the kernel 202d3da701dSRashmica Gupta * and attempt to add them back to the kernel. 203d3da701dSRashmica Gupta */ 204d3da701dSRashmica Gupta static int memtrace_online(void) 205d3da701dSRashmica Gupta { 206d3da701dSRashmica Gupta int i, ret = 0; 207d3da701dSRashmica Gupta struct memtrace_entry *ent; 208d3da701dSRashmica Gupta 209d3da701dSRashmica Gupta for (i = memtrace_array_nr - 1; i >= 0; i--) { 210d3da701dSRashmica Gupta ent = &memtrace_array[i]; 211d3da701dSRashmica Gupta 212d3da701dSRashmica Gupta /* We have onlined this chunk previously */ 213d3da701dSRashmica Gupta if (ent->nid == -1) 214d3da701dSRashmica Gupta continue; 215d3da701dSRashmica Gupta 216d3da701dSRashmica Gupta /* Remove from io mappings */ 217d3da701dSRashmica Gupta if (ent->mem) { 218d3da701dSRashmica Gupta iounmap(ent->mem); 219d3da701dSRashmica Gupta ent->mem = 0; 220d3da701dSRashmica Gupta } 221d3da701dSRashmica Gupta 222d3da701dSRashmica Gupta if (add_memory(ent->nid, ent->start, ent->size)) { 223d3da701dSRashmica Gupta pr_err("Failed to add trace memory to node %d\n", 224d3da701dSRashmica Gupta ent->nid); 225d3da701dSRashmica Gupta ret += 1; 226d3da701dSRashmica Gupta continue; 227d3da701dSRashmica Gupta } 228d3da701dSRashmica Gupta 229d3da701dSRashmica Gupta /* 230d3da701dSRashmica Gupta * If kernel isn't compiled with the auto online option 231d3da701dSRashmica Gupta * we need to online the memory ourselves. 232d3da701dSRashmica Gupta */ 233d3da701dSRashmica Gupta if (!memhp_auto_online) { 234d3da701dSRashmica Gupta walk_memory_range(PFN_DOWN(ent->start), 235d3da701dSRashmica Gupta PFN_UP(ent->start + ent->size - 1), 236d3da701dSRashmica Gupta NULL, online_mem_block); 237d3da701dSRashmica Gupta } 238d3da701dSRashmica Gupta 239d3da701dSRashmica Gupta /* 240d3da701dSRashmica Gupta * Memory was added successfully so clean up references to it 241d3da701dSRashmica Gupta * so on reentry we can tell that this chunk was added. 242d3da701dSRashmica Gupta */ 243d3da701dSRashmica Gupta debugfs_remove_recursive(ent->dir); 244d3da701dSRashmica Gupta pr_info("Added trace memory back to node %d\n", ent->nid); 245d3da701dSRashmica Gupta ent->size = ent->start = ent->nid = -1; 246d3da701dSRashmica Gupta } 247d3da701dSRashmica Gupta if (ret) 248d3da701dSRashmica Gupta return ret; 249d3da701dSRashmica Gupta 250d3da701dSRashmica Gupta /* If all chunks of memory were added successfully, reset globals */ 251d3da701dSRashmica Gupta kfree(memtrace_array); 252d3da701dSRashmica Gupta memtrace_array = NULL; 253d3da701dSRashmica Gupta memtrace_size = 0; 254d3da701dSRashmica Gupta memtrace_array_nr = 0; 255d3da701dSRashmica Gupta return 0; 256d3da701dSRashmica Gupta } 257d3da701dSRashmica Gupta 2589d5171a8SRashmica Gupta static int memtrace_enable_set(void *data, u64 val) 2599d5171a8SRashmica Gupta { 260d3da701dSRashmica Gupta u64 bytes; 261d3da701dSRashmica Gupta 262d3da701dSRashmica Gupta /* 263d3da701dSRashmica Gupta * Don't attempt to do anything if size isn't aligned to a memory 264d3da701dSRashmica Gupta * block or equal to zero. 265d3da701dSRashmica Gupta */ 266d3da701dSRashmica Gupta bytes = memory_block_size_bytes(); 267d3da701dSRashmica Gupta if (val & (bytes - 1)) { 268d3da701dSRashmica Gupta pr_err("Value must be aligned with 0x%llx\n", bytes); 2699d5171a8SRashmica Gupta return -EINVAL; 270d3da701dSRashmica Gupta } 271d3da701dSRashmica Gupta 272d3da701dSRashmica Gupta /* Re-add/online previously removed/offlined memory */ 273d3da701dSRashmica Gupta if (memtrace_size) { 274d3da701dSRashmica Gupta if (memtrace_online()) 275d3da701dSRashmica Gupta return -EAGAIN; 276d3da701dSRashmica Gupta } 2779d5171a8SRashmica Gupta 2789d5171a8SRashmica Gupta if (!val) 279d3da701dSRashmica Gupta return 0; 2809d5171a8SRashmica Gupta 281d3da701dSRashmica Gupta /* Offline and remove memory */ 2829d5171a8SRashmica Gupta if (memtrace_init_regions_runtime(val)) 2839d5171a8SRashmica Gupta return -EINVAL; 2849d5171a8SRashmica Gupta 2859d5171a8SRashmica Gupta if (memtrace_init_debugfs()) 2869d5171a8SRashmica Gupta return -EINVAL; 2879d5171a8SRashmica Gupta 2889d5171a8SRashmica Gupta memtrace_size = val; 2899d5171a8SRashmica Gupta 2909d5171a8SRashmica Gupta return 0; 2919d5171a8SRashmica Gupta } 2929d5171a8SRashmica Gupta 2939d5171a8SRashmica Gupta static int memtrace_enable_get(void *data, u64 *val) 2949d5171a8SRashmica Gupta { 2959d5171a8SRashmica Gupta *val = memtrace_size; 2969d5171a8SRashmica Gupta return 0; 2979d5171a8SRashmica Gupta } 2989d5171a8SRashmica Gupta 2999d5171a8SRashmica Gupta DEFINE_SIMPLE_ATTRIBUTE(memtrace_init_fops, memtrace_enable_get, 3009d5171a8SRashmica Gupta memtrace_enable_set, "0x%016llx\n"); 3019d5171a8SRashmica Gupta 3029d5171a8SRashmica Gupta static int memtrace_init(void) 3039d5171a8SRashmica Gupta { 3049d5171a8SRashmica Gupta memtrace_debugfs_dir = debugfs_create_dir("memtrace", 3059d5171a8SRashmica Gupta powerpc_debugfs_root); 3069d5171a8SRashmica Gupta if (!memtrace_debugfs_dir) 3079d5171a8SRashmica Gupta return -1; 3089d5171a8SRashmica Gupta 3099d5171a8SRashmica Gupta debugfs_create_file("enable", 0600, memtrace_debugfs_dir, 3109d5171a8SRashmica Gupta NULL, &memtrace_init_fops); 3119d5171a8SRashmica Gupta 3129d5171a8SRashmica Gupta return 0; 3139d5171a8SRashmica Gupta } 3149d5171a8SRashmica Gupta machine_device_initcall(powernv, memtrace_init); 315