12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 29d5171a8SRashmica Gupta /* 39d5171a8SRashmica Gupta * Copyright (C) IBM Corporation, 2014, 2017 49d5171a8SRashmica Gupta * Anton Blanchard, Rashmica Gupta. 59d5171a8SRashmica Gupta */ 69d5171a8SRashmica Gupta 79d5171a8SRashmica Gupta #define pr_fmt(fmt) "memtrace: " fmt 89d5171a8SRashmica Gupta 99d5171a8SRashmica Gupta #include <linux/bitops.h> 109d5171a8SRashmica Gupta #include <linux/string.h> 119d5171a8SRashmica Gupta #include <linux/memblock.h> 129d5171a8SRashmica Gupta #include <linux/init.h> 139d5171a8SRashmica Gupta #include <linux/moduleparam.h> 149d5171a8SRashmica Gupta #include <linux/fs.h> 159d5171a8SRashmica Gupta #include <linux/debugfs.h> 169d5171a8SRashmica Gupta #include <linux/slab.h> 179d5171a8SRashmica Gupta #include <linux/memory.h> 189d5171a8SRashmica Gupta #include <linux/memory_hotplug.h> 1998fa15f3SAnshuman Khandual #include <linux/numa.h> 209d5171a8SRashmica Gupta #include <asm/machdep.h> 219d5171a8SRashmica Gupta #include <asm/debugfs.h> 229d5171a8SRashmica Gupta 239d5171a8SRashmica Gupta /* This enables us to keep track of the memory removed from each node. */ 249d5171a8SRashmica Gupta struct memtrace_entry { 259d5171a8SRashmica Gupta void *mem; 269d5171a8SRashmica Gupta u64 start; 279d5171a8SRashmica Gupta u64 size; 289d5171a8SRashmica Gupta u32 nid; 299d5171a8SRashmica Gupta struct dentry *dir; 309d5171a8SRashmica Gupta char name[16]; 319d5171a8SRashmica Gupta }; 329d5171a8SRashmica Gupta 339d5171a8SRashmica Gupta static u64 memtrace_size; 349d5171a8SRashmica Gupta 359d5171a8SRashmica Gupta static struct memtrace_entry *memtrace_array; 369d5171a8SRashmica Gupta static unsigned int memtrace_array_nr; 379d5171a8SRashmica Gupta 389d5171a8SRashmica Gupta 399d5171a8SRashmica Gupta static ssize_t memtrace_read(struct file *filp, char __user *ubuf, 409d5171a8SRashmica Gupta size_t count, loff_t *ppos) 419d5171a8SRashmica Gupta { 429d5171a8SRashmica Gupta struct memtrace_entry *ent = filp->private_data; 439d5171a8SRashmica Gupta 449d5171a8SRashmica Gupta return simple_read_from_buffer(ubuf, count, ppos, ent->mem, ent->size); 459d5171a8SRashmica Gupta } 469d5171a8SRashmica Gupta 479d5171a8SRashmica Gupta static const struct file_operations memtrace_fops = { 489d5171a8SRashmica Gupta .llseek = default_llseek, 499d5171a8SRashmica Gupta .read = memtrace_read, 509d5171a8SRashmica Gupta .open = simple_open, 519d5171a8SRashmica Gupta }; 529d5171a8SRashmica Gupta 539d5171a8SRashmica Gupta static int check_memblock_online(struct memory_block *mem, void *arg) 549d5171a8SRashmica Gupta { 559d5171a8SRashmica Gupta if (mem->state != MEM_ONLINE) 569d5171a8SRashmica Gupta return -1; 579d5171a8SRashmica Gupta 589d5171a8SRashmica Gupta return 0; 599d5171a8SRashmica Gupta } 609d5171a8SRashmica Gupta 619d5171a8SRashmica Gupta static int change_memblock_state(struct memory_block *mem, void *arg) 629d5171a8SRashmica Gupta { 639d5171a8SRashmica Gupta unsigned long state = (unsigned long)arg; 649d5171a8SRashmica Gupta 659d5171a8SRashmica Gupta mem->state = state; 669d5171a8SRashmica Gupta 679d5171a8SRashmica Gupta return 0; 689d5171a8SRashmica Gupta } 699d5171a8SRashmica Gupta 7056668487SDavid Hildenbrand /* called with device_hotplug_lock held */ 719d5171a8SRashmica Gupta static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) 729d5171a8SRashmica Gupta { 739d5171a8SRashmica Gupta u64 end_pfn = start_pfn + nr_pages - 1; 749d5171a8SRashmica Gupta 759d5171a8SRashmica Gupta if (walk_memory_range(start_pfn, end_pfn, NULL, 769d5171a8SRashmica Gupta check_memblock_online)) 779d5171a8SRashmica Gupta return false; 789d5171a8SRashmica Gupta 799d5171a8SRashmica Gupta walk_memory_range(start_pfn, end_pfn, (void *)MEM_GOING_OFFLINE, 809d5171a8SRashmica Gupta change_memblock_state); 819d5171a8SRashmica Gupta 829d5171a8SRashmica Gupta if (offline_pages(start_pfn, nr_pages)) { 839d5171a8SRashmica Gupta walk_memory_range(start_pfn, end_pfn, (void *)MEM_ONLINE, 849d5171a8SRashmica Gupta change_memblock_state); 859d5171a8SRashmica Gupta return false; 869d5171a8SRashmica Gupta } 879d5171a8SRashmica Gupta 889d5171a8SRashmica Gupta walk_memory_range(start_pfn, end_pfn, (void *)MEM_OFFLINE, 899d5171a8SRashmica Gupta change_memblock_state); 909d5171a8SRashmica Gupta 919d5171a8SRashmica Gupta 929d5171a8SRashmica Gupta return true; 939d5171a8SRashmica Gupta } 949d5171a8SRashmica Gupta 959d5171a8SRashmica Gupta static u64 memtrace_alloc_node(u32 nid, u64 size) 969d5171a8SRashmica Gupta { 973f7daf3dSRashmica Gupta u64 start_pfn, end_pfn, nr_pages, pfn; 989d5171a8SRashmica Gupta u64 base_pfn; 993f7daf3dSRashmica Gupta u64 bytes = memory_block_size_bytes(); 1009d5171a8SRashmica Gupta 1018ccb442dSMichael Ellerman if (!node_spanned_pages(nid)) 1029d5171a8SRashmica Gupta return 0; 1039d5171a8SRashmica Gupta 1049d5171a8SRashmica Gupta start_pfn = node_start_pfn(nid); 1059d5171a8SRashmica Gupta end_pfn = node_end_pfn(nid); 1069d5171a8SRashmica Gupta nr_pages = size >> PAGE_SHIFT; 1079d5171a8SRashmica Gupta 1089d5171a8SRashmica Gupta /* Trace memory needs to be aligned to the size */ 1099d5171a8SRashmica Gupta end_pfn = round_down(end_pfn - nr_pages, nr_pages); 1109d5171a8SRashmica Gupta 11156668487SDavid Hildenbrand lock_device_hotplug(); 1129d5171a8SRashmica Gupta for (base_pfn = end_pfn; base_pfn > start_pfn; base_pfn -= nr_pages) { 1133f7daf3dSRashmica Gupta if (memtrace_offline_pages(nid, base_pfn, nr_pages) == true) { 1143f7daf3dSRashmica Gupta /* 1153f7daf3dSRashmica Gupta * Remove memory in memory block size chunks so that 1163f7daf3dSRashmica Gupta * iomem resources are always split to the same size and 1173f7daf3dSRashmica Gupta * we never try to remove memory that spans two iomem 1183f7daf3dSRashmica Gupta * resources. 1193f7daf3dSRashmica Gupta */ 1203f7daf3dSRashmica Gupta end_pfn = base_pfn + nr_pages; 1213f7daf3dSRashmica Gupta for (pfn = base_pfn; pfn < end_pfn; pfn += bytes>> PAGE_SHIFT) { 122d15e5926SDavid Hildenbrand __remove_memory(nid, pfn << PAGE_SHIFT, bytes); 1233f7daf3dSRashmica Gupta } 1243f7daf3dSRashmica Gupta unlock_device_hotplug(); 1259d5171a8SRashmica Gupta return base_pfn << PAGE_SHIFT; 1269d5171a8SRashmica Gupta } 1273f7daf3dSRashmica Gupta } 12856668487SDavid Hildenbrand unlock_device_hotplug(); 1299d5171a8SRashmica Gupta 1309d5171a8SRashmica Gupta return 0; 1319d5171a8SRashmica Gupta } 1329d5171a8SRashmica Gupta 1339d5171a8SRashmica Gupta static int memtrace_init_regions_runtime(u64 size) 1349d5171a8SRashmica Gupta { 1359d5171a8SRashmica Gupta u32 nid; 1369d5171a8SRashmica Gupta u64 m; 1379d5171a8SRashmica Gupta 1389d5171a8SRashmica Gupta memtrace_array = kcalloc(num_online_nodes(), 1399d5171a8SRashmica Gupta sizeof(struct memtrace_entry), GFP_KERNEL); 1409d5171a8SRashmica Gupta if (!memtrace_array) { 1419d5171a8SRashmica Gupta pr_err("Failed to allocate memtrace_array\n"); 1429d5171a8SRashmica Gupta return -EINVAL; 1439d5171a8SRashmica Gupta } 1449d5171a8SRashmica Gupta 1459d5171a8SRashmica Gupta for_each_online_node(nid) { 1469d5171a8SRashmica Gupta m = memtrace_alloc_node(nid, size); 1479d5171a8SRashmica Gupta 1489d5171a8SRashmica Gupta /* 1499d5171a8SRashmica Gupta * A node might not have any local memory, so warn but 1509d5171a8SRashmica Gupta * continue on. 1519d5171a8SRashmica Gupta */ 1529d5171a8SRashmica Gupta if (!m) { 1539d5171a8SRashmica Gupta pr_err("Failed to allocate trace memory on node %d\n", nid); 1549d5171a8SRashmica Gupta continue; 1559d5171a8SRashmica Gupta } 1569d5171a8SRashmica Gupta 1579d5171a8SRashmica Gupta pr_info("Allocated trace memory on node %d at 0x%016llx\n", nid, m); 1589d5171a8SRashmica Gupta 1599d5171a8SRashmica Gupta memtrace_array[memtrace_array_nr].start = m; 1609d5171a8SRashmica Gupta memtrace_array[memtrace_array_nr].size = size; 1619d5171a8SRashmica Gupta memtrace_array[memtrace_array_nr].nid = nid; 1629d5171a8SRashmica Gupta memtrace_array_nr++; 1639d5171a8SRashmica Gupta } 1649d5171a8SRashmica Gupta 1659d5171a8SRashmica Gupta return 0; 1669d5171a8SRashmica Gupta } 1679d5171a8SRashmica Gupta 1689d5171a8SRashmica Gupta static struct dentry *memtrace_debugfs_dir; 1699d5171a8SRashmica Gupta 1709d5171a8SRashmica Gupta static int memtrace_init_debugfs(void) 1719d5171a8SRashmica Gupta { 1729d5171a8SRashmica Gupta int ret = 0; 1739d5171a8SRashmica Gupta int i; 1749d5171a8SRashmica Gupta 1759d5171a8SRashmica Gupta for (i = 0; i < memtrace_array_nr; i++) { 1769d5171a8SRashmica Gupta struct dentry *dir; 1779d5171a8SRashmica Gupta struct memtrace_entry *ent = &memtrace_array[i]; 1789d5171a8SRashmica Gupta 1799d5171a8SRashmica Gupta ent->mem = ioremap(ent->start, ent->size); 1809d5171a8SRashmica Gupta /* Warn but continue on */ 1819d5171a8SRashmica Gupta if (!ent->mem) { 1829d5171a8SRashmica Gupta pr_err("Failed to map trace memory at 0x%llx\n", 1839d5171a8SRashmica Gupta ent->start); 1849d5171a8SRashmica Gupta ret = -1; 1859d5171a8SRashmica Gupta continue; 1869d5171a8SRashmica Gupta } 1879d5171a8SRashmica Gupta 1889d5171a8SRashmica Gupta snprintf(ent->name, 16, "%08x", ent->nid); 1899d5171a8SRashmica Gupta dir = debugfs_create_dir(ent->name, memtrace_debugfs_dir); 190d3da701dSRashmica Gupta if (!dir) { 191d3da701dSRashmica Gupta pr_err("Failed to create debugfs directory for node %d\n", 192d3da701dSRashmica Gupta ent->nid); 1939d5171a8SRashmica Gupta return -1; 194d3da701dSRashmica Gupta } 1959d5171a8SRashmica Gupta 1969d5171a8SRashmica Gupta ent->dir = dir; 1979d5171a8SRashmica Gupta debugfs_create_file("trace", 0400, dir, ent, &memtrace_fops); 1989d5171a8SRashmica Gupta debugfs_create_x64("start", 0400, dir, &ent->start); 1999d5171a8SRashmica Gupta debugfs_create_x64("size", 0400, dir, &ent->size); 2009d5171a8SRashmica Gupta } 2019d5171a8SRashmica Gupta 2029d5171a8SRashmica Gupta return ret; 2039d5171a8SRashmica Gupta } 2049d5171a8SRashmica Gupta 205d3da701dSRashmica Gupta static int online_mem_block(struct memory_block *mem, void *arg) 206d3da701dSRashmica Gupta { 207d3da701dSRashmica Gupta return device_online(&mem->dev); 208d3da701dSRashmica Gupta } 209d3da701dSRashmica Gupta 210d3da701dSRashmica Gupta /* 211d3da701dSRashmica Gupta * Iterate through the chunks of memory we have removed from the kernel 212d3da701dSRashmica Gupta * and attempt to add them back to the kernel. 213d3da701dSRashmica Gupta */ 214d3da701dSRashmica Gupta static int memtrace_online(void) 215d3da701dSRashmica Gupta { 216d3da701dSRashmica Gupta int i, ret = 0; 217d3da701dSRashmica Gupta struct memtrace_entry *ent; 218d3da701dSRashmica Gupta 219d3da701dSRashmica Gupta for (i = memtrace_array_nr - 1; i >= 0; i--) { 220d3da701dSRashmica Gupta ent = &memtrace_array[i]; 221d3da701dSRashmica Gupta 222d3da701dSRashmica Gupta /* We have onlined this chunk previously */ 22398fa15f3SAnshuman Khandual if (ent->nid == NUMA_NO_NODE) 224d3da701dSRashmica Gupta continue; 225d3da701dSRashmica Gupta 226d3da701dSRashmica Gupta /* Remove from io mappings */ 227d3da701dSRashmica Gupta if (ent->mem) { 228d3da701dSRashmica Gupta iounmap(ent->mem); 229d3da701dSRashmica Gupta ent->mem = 0; 230d3da701dSRashmica Gupta } 231d3da701dSRashmica Gupta 232d3da701dSRashmica Gupta if (add_memory(ent->nid, ent->start, ent->size)) { 233d3da701dSRashmica Gupta pr_err("Failed to add trace memory to node %d\n", 234d3da701dSRashmica Gupta ent->nid); 235d3da701dSRashmica Gupta ret += 1; 236d3da701dSRashmica Gupta continue; 237d3da701dSRashmica Gupta } 238d3da701dSRashmica Gupta 239d3da701dSRashmica Gupta /* 240d3da701dSRashmica Gupta * If kernel isn't compiled with the auto online option 241d3da701dSRashmica Gupta * we need to online the memory ourselves. 242d3da701dSRashmica Gupta */ 243d3da701dSRashmica Gupta if (!memhp_auto_online) { 244cec16805SDavid Hildenbrand lock_device_hotplug(); 245d3da701dSRashmica Gupta walk_memory_range(PFN_DOWN(ent->start), 246d3da701dSRashmica Gupta PFN_UP(ent->start + ent->size - 1), 247d3da701dSRashmica Gupta NULL, online_mem_block); 248cec16805SDavid Hildenbrand unlock_device_hotplug(); 249d3da701dSRashmica Gupta } 250d3da701dSRashmica Gupta 251d3da701dSRashmica Gupta /* 252d3da701dSRashmica Gupta * Memory was added successfully so clean up references to it 253d3da701dSRashmica Gupta * so on reentry we can tell that this chunk was added. 254d3da701dSRashmica Gupta */ 255d3da701dSRashmica Gupta debugfs_remove_recursive(ent->dir); 256d3da701dSRashmica Gupta pr_info("Added trace memory back to node %d\n", ent->nid); 25798fa15f3SAnshuman Khandual ent->size = ent->start = ent->nid = NUMA_NO_NODE; 258d3da701dSRashmica Gupta } 259d3da701dSRashmica Gupta if (ret) 260d3da701dSRashmica Gupta return ret; 261d3da701dSRashmica Gupta 262d3da701dSRashmica Gupta /* If all chunks of memory were added successfully, reset globals */ 263d3da701dSRashmica Gupta kfree(memtrace_array); 264d3da701dSRashmica Gupta memtrace_array = NULL; 265d3da701dSRashmica Gupta memtrace_size = 0; 266d3da701dSRashmica Gupta memtrace_array_nr = 0; 267d3da701dSRashmica Gupta return 0; 268d3da701dSRashmica Gupta } 269d3da701dSRashmica Gupta 2709d5171a8SRashmica Gupta static int memtrace_enable_set(void *data, u64 val) 2719d5171a8SRashmica Gupta { 272d3da701dSRashmica Gupta u64 bytes; 273d3da701dSRashmica Gupta 274d3da701dSRashmica Gupta /* 275d3da701dSRashmica Gupta * Don't attempt to do anything if size isn't aligned to a memory 276d3da701dSRashmica Gupta * block or equal to zero. 277d3da701dSRashmica Gupta */ 278d3da701dSRashmica Gupta bytes = memory_block_size_bytes(); 279d3da701dSRashmica Gupta if (val & (bytes - 1)) { 280d3da701dSRashmica Gupta pr_err("Value must be aligned with 0x%llx\n", bytes); 2819d5171a8SRashmica Gupta return -EINVAL; 282d3da701dSRashmica Gupta } 283d3da701dSRashmica Gupta 284d3da701dSRashmica Gupta /* Re-add/online previously removed/offlined memory */ 285d3da701dSRashmica Gupta if (memtrace_size) { 286d3da701dSRashmica Gupta if (memtrace_online()) 287d3da701dSRashmica Gupta return -EAGAIN; 288d3da701dSRashmica Gupta } 2899d5171a8SRashmica Gupta 2909d5171a8SRashmica Gupta if (!val) 291d3da701dSRashmica Gupta return 0; 2929d5171a8SRashmica Gupta 293d3da701dSRashmica Gupta /* Offline and remove memory */ 2949d5171a8SRashmica Gupta if (memtrace_init_regions_runtime(val)) 2959d5171a8SRashmica Gupta return -EINVAL; 2969d5171a8SRashmica Gupta 2979d5171a8SRashmica Gupta if (memtrace_init_debugfs()) 2989d5171a8SRashmica Gupta return -EINVAL; 2999d5171a8SRashmica Gupta 3009d5171a8SRashmica Gupta memtrace_size = val; 3019d5171a8SRashmica Gupta 3029d5171a8SRashmica Gupta return 0; 3039d5171a8SRashmica Gupta } 3049d5171a8SRashmica Gupta 3059d5171a8SRashmica Gupta static int memtrace_enable_get(void *data, u64 *val) 3069d5171a8SRashmica Gupta { 3079d5171a8SRashmica Gupta *val = memtrace_size; 3089d5171a8SRashmica Gupta return 0; 3099d5171a8SRashmica Gupta } 3109d5171a8SRashmica Gupta 3119d5171a8SRashmica Gupta DEFINE_SIMPLE_ATTRIBUTE(memtrace_init_fops, memtrace_enable_get, 3129d5171a8SRashmica Gupta memtrace_enable_set, "0x%016llx\n"); 3139d5171a8SRashmica Gupta 3149d5171a8SRashmica Gupta static int memtrace_init(void) 3159d5171a8SRashmica Gupta { 3169d5171a8SRashmica Gupta memtrace_debugfs_dir = debugfs_create_dir("memtrace", 3179d5171a8SRashmica Gupta powerpc_debugfs_root); 3189d5171a8SRashmica Gupta if (!memtrace_debugfs_dir) 3199d5171a8SRashmica Gupta return -1; 3209d5171a8SRashmica Gupta 3219d5171a8SRashmica Gupta debugfs_create_file("enable", 0600, memtrace_debugfs_dir, 3229d5171a8SRashmica Gupta NULL, &memtrace_init_fops); 3239d5171a8SRashmica Gupta 3249d5171a8SRashmica Gupta return 0; 3259d5171a8SRashmica Gupta } 3269d5171a8SRashmica Gupta machine_device_initcall(powernv, memtrace_init); 327