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 bool valid_memtrace_range(struct memtrace_entry *dev, 519d5171a8SRashmica Gupta unsigned long start, unsigned long size) 529d5171a8SRashmica Gupta { 539d5171a8SRashmica Gupta if ((start >= dev->start) && 549d5171a8SRashmica Gupta ((start + size) <= (dev->start + dev->size))) 559d5171a8SRashmica Gupta return true; 569d5171a8SRashmica Gupta 579d5171a8SRashmica Gupta return false; 589d5171a8SRashmica Gupta } 599d5171a8SRashmica Gupta 609d5171a8SRashmica Gupta static int memtrace_mmap(struct file *filp, struct vm_area_struct *vma) 619d5171a8SRashmica Gupta { 629d5171a8SRashmica Gupta unsigned long size = vma->vm_end - vma->vm_start; 639d5171a8SRashmica Gupta struct memtrace_entry *dev = filp->private_data; 649d5171a8SRashmica Gupta 659d5171a8SRashmica Gupta if (!valid_memtrace_range(dev, vma->vm_pgoff << PAGE_SHIFT, size)) 669d5171a8SRashmica Gupta return -EINVAL; 679d5171a8SRashmica Gupta 689d5171a8SRashmica Gupta vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); 699d5171a8SRashmica Gupta 709d5171a8SRashmica Gupta if (remap_pfn_range(vma, vma->vm_start, 719d5171a8SRashmica Gupta vma->vm_pgoff + (dev->start >> PAGE_SHIFT), 729d5171a8SRashmica Gupta size, vma->vm_page_prot)) 739d5171a8SRashmica Gupta return -EAGAIN; 749d5171a8SRashmica Gupta 759d5171a8SRashmica Gupta return 0; 769d5171a8SRashmica Gupta } 779d5171a8SRashmica Gupta 789d5171a8SRashmica Gupta static const struct file_operations memtrace_fops = { 799d5171a8SRashmica Gupta .llseek = default_llseek, 809d5171a8SRashmica Gupta .read = memtrace_read, 819d5171a8SRashmica Gupta .mmap = memtrace_mmap, 829d5171a8SRashmica Gupta .open = simple_open, 839d5171a8SRashmica Gupta }; 849d5171a8SRashmica Gupta 859d5171a8SRashmica Gupta static void flush_memory_region(u64 base, u64 size) 869d5171a8SRashmica Gupta { 879d5171a8SRashmica Gupta unsigned long line_size = ppc64_caches.l1d.size; 889d5171a8SRashmica Gupta u64 end = base + size; 899d5171a8SRashmica Gupta u64 addr; 909d5171a8SRashmica Gupta 919d5171a8SRashmica Gupta base = round_down(base, line_size); 929d5171a8SRashmica Gupta end = round_up(end, line_size); 939d5171a8SRashmica Gupta 949d5171a8SRashmica Gupta for (addr = base; addr < end; addr += line_size) 959d5171a8SRashmica Gupta asm volatile("dcbf 0,%0" : "=r" (addr) :: "memory"); 969d5171a8SRashmica Gupta } 979d5171a8SRashmica Gupta 989d5171a8SRashmica Gupta static int check_memblock_online(struct memory_block *mem, void *arg) 999d5171a8SRashmica Gupta { 1009d5171a8SRashmica Gupta if (mem->state != MEM_ONLINE) 1019d5171a8SRashmica Gupta return -1; 1029d5171a8SRashmica Gupta 1039d5171a8SRashmica Gupta return 0; 1049d5171a8SRashmica Gupta } 1059d5171a8SRashmica Gupta 1069d5171a8SRashmica Gupta static int change_memblock_state(struct memory_block *mem, void *arg) 1079d5171a8SRashmica Gupta { 1089d5171a8SRashmica Gupta unsigned long state = (unsigned long)arg; 1099d5171a8SRashmica Gupta 1109d5171a8SRashmica Gupta mem->state = state; 1119d5171a8SRashmica Gupta 1129d5171a8SRashmica Gupta return 0; 1139d5171a8SRashmica Gupta } 1149d5171a8SRashmica Gupta 1159d5171a8SRashmica Gupta static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) 1169d5171a8SRashmica Gupta { 1179d5171a8SRashmica Gupta u64 end_pfn = start_pfn + nr_pages - 1; 1189d5171a8SRashmica Gupta 1199d5171a8SRashmica Gupta if (walk_memory_range(start_pfn, end_pfn, NULL, 1209d5171a8SRashmica Gupta check_memblock_online)) 1219d5171a8SRashmica Gupta return false; 1229d5171a8SRashmica Gupta 1239d5171a8SRashmica Gupta walk_memory_range(start_pfn, end_pfn, (void *)MEM_GOING_OFFLINE, 1249d5171a8SRashmica Gupta change_memblock_state); 1259d5171a8SRashmica Gupta 1269d5171a8SRashmica Gupta if (offline_pages(start_pfn, nr_pages)) { 1279d5171a8SRashmica Gupta walk_memory_range(start_pfn, end_pfn, (void *)MEM_ONLINE, 1289d5171a8SRashmica Gupta change_memblock_state); 1299d5171a8SRashmica Gupta return false; 1309d5171a8SRashmica Gupta } 1319d5171a8SRashmica Gupta 1329d5171a8SRashmica Gupta walk_memory_range(start_pfn, end_pfn, (void *)MEM_OFFLINE, 1339d5171a8SRashmica Gupta change_memblock_state); 1349d5171a8SRashmica Gupta 1359d5171a8SRashmica Gupta /* RCU grace period? */ 1369d5171a8SRashmica Gupta flush_memory_region((u64)__va(start_pfn << PAGE_SHIFT), 1379d5171a8SRashmica Gupta nr_pages << PAGE_SHIFT); 1389d5171a8SRashmica Gupta 1399d5171a8SRashmica Gupta lock_device_hotplug(); 1409d5171a8SRashmica Gupta remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT); 1419d5171a8SRashmica Gupta unlock_device_hotplug(); 1429d5171a8SRashmica Gupta 1439d5171a8SRashmica Gupta return true; 1449d5171a8SRashmica Gupta } 1459d5171a8SRashmica Gupta 1469d5171a8SRashmica Gupta static u64 memtrace_alloc_node(u32 nid, u64 size) 1479d5171a8SRashmica Gupta { 1489d5171a8SRashmica Gupta u64 start_pfn, end_pfn, nr_pages; 1499d5171a8SRashmica Gupta u64 base_pfn; 1509d5171a8SRashmica Gupta 1519d5171a8SRashmica Gupta if (!NODE_DATA(nid) || !node_spanned_pages(nid)) 1529d5171a8SRashmica Gupta return 0; 1539d5171a8SRashmica Gupta 1549d5171a8SRashmica Gupta start_pfn = node_start_pfn(nid); 1559d5171a8SRashmica Gupta end_pfn = node_end_pfn(nid); 1569d5171a8SRashmica Gupta nr_pages = size >> PAGE_SHIFT; 1579d5171a8SRashmica Gupta 1589d5171a8SRashmica Gupta /* Trace memory needs to be aligned to the size */ 1599d5171a8SRashmica Gupta end_pfn = round_down(end_pfn - nr_pages, nr_pages); 1609d5171a8SRashmica Gupta 1619d5171a8SRashmica Gupta for (base_pfn = end_pfn; base_pfn > start_pfn; base_pfn -= nr_pages) { 1629d5171a8SRashmica Gupta if (memtrace_offline_pages(nid, base_pfn, nr_pages) == true) 1639d5171a8SRashmica Gupta return base_pfn << PAGE_SHIFT; 1649d5171a8SRashmica Gupta } 1659d5171a8SRashmica Gupta 1669d5171a8SRashmica Gupta return 0; 1679d5171a8SRashmica Gupta } 1689d5171a8SRashmica Gupta 1699d5171a8SRashmica Gupta static int memtrace_init_regions_runtime(u64 size) 1709d5171a8SRashmica Gupta { 1719d5171a8SRashmica Gupta u32 nid; 1729d5171a8SRashmica Gupta u64 m; 1739d5171a8SRashmica Gupta 1749d5171a8SRashmica Gupta memtrace_array = kcalloc(num_online_nodes(), 1759d5171a8SRashmica Gupta sizeof(struct memtrace_entry), GFP_KERNEL); 1769d5171a8SRashmica Gupta if (!memtrace_array) { 1779d5171a8SRashmica Gupta pr_err("Failed to allocate memtrace_array\n"); 1789d5171a8SRashmica Gupta return -EINVAL; 1799d5171a8SRashmica Gupta } 1809d5171a8SRashmica Gupta 1819d5171a8SRashmica Gupta for_each_online_node(nid) { 1829d5171a8SRashmica Gupta m = memtrace_alloc_node(nid, size); 1839d5171a8SRashmica Gupta 1849d5171a8SRashmica Gupta /* 1859d5171a8SRashmica Gupta * A node might not have any local memory, so warn but 1869d5171a8SRashmica Gupta * continue on. 1879d5171a8SRashmica Gupta */ 1889d5171a8SRashmica Gupta if (!m) { 1899d5171a8SRashmica Gupta pr_err("Failed to allocate trace memory on node %d\n", nid); 1909d5171a8SRashmica Gupta continue; 1919d5171a8SRashmica Gupta } 1929d5171a8SRashmica Gupta 1939d5171a8SRashmica Gupta pr_info("Allocated trace memory on node %d at 0x%016llx\n", nid, m); 1949d5171a8SRashmica Gupta 1959d5171a8SRashmica Gupta memtrace_array[memtrace_array_nr].start = m; 1969d5171a8SRashmica Gupta memtrace_array[memtrace_array_nr].size = size; 1979d5171a8SRashmica Gupta memtrace_array[memtrace_array_nr].nid = nid; 1989d5171a8SRashmica Gupta memtrace_array_nr++; 1999d5171a8SRashmica Gupta } 2009d5171a8SRashmica Gupta 2019d5171a8SRashmica Gupta return 0; 2029d5171a8SRashmica Gupta } 2039d5171a8SRashmica Gupta 2049d5171a8SRashmica Gupta static struct dentry *memtrace_debugfs_dir; 2059d5171a8SRashmica Gupta 2069d5171a8SRashmica Gupta static int memtrace_init_debugfs(void) 2079d5171a8SRashmica Gupta { 2089d5171a8SRashmica Gupta int ret = 0; 2099d5171a8SRashmica Gupta int i; 2109d5171a8SRashmica Gupta 2119d5171a8SRashmica Gupta for (i = 0; i < memtrace_array_nr; i++) { 2129d5171a8SRashmica Gupta struct dentry *dir; 2139d5171a8SRashmica Gupta struct memtrace_entry *ent = &memtrace_array[i]; 2149d5171a8SRashmica Gupta 2159d5171a8SRashmica Gupta ent->mem = ioremap(ent->start, ent->size); 2169d5171a8SRashmica Gupta /* Warn but continue on */ 2179d5171a8SRashmica Gupta if (!ent->mem) { 2189d5171a8SRashmica Gupta pr_err("Failed to map trace memory at 0x%llx\n", 2199d5171a8SRashmica Gupta ent->start); 2209d5171a8SRashmica Gupta ret = -1; 2219d5171a8SRashmica Gupta continue; 2229d5171a8SRashmica Gupta } 2239d5171a8SRashmica Gupta 2249d5171a8SRashmica Gupta snprintf(ent->name, 16, "%08x", ent->nid); 2259d5171a8SRashmica Gupta dir = debugfs_create_dir(ent->name, memtrace_debugfs_dir); 2269d5171a8SRashmica Gupta if (!dir) 2279d5171a8SRashmica Gupta return -1; 2289d5171a8SRashmica Gupta 2299d5171a8SRashmica Gupta ent->dir = dir; 2309d5171a8SRashmica Gupta debugfs_create_file("trace", 0400, dir, ent, &memtrace_fops); 2319d5171a8SRashmica Gupta debugfs_create_x64("start", 0400, dir, &ent->start); 2329d5171a8SRashmica Gupta debugfs_create_x64("size", 0400, dir, &ent->size); 2339d5171a8SRashmica Gupta } 2349d5171a8SRashmica Gupta 2359d5171a8SRashmica Gupta return ret; 2369d5171a8SRashmica Gupta } 2379d5171a8SRashmica Gupta 2389d5171a8SRashmica Gupta static int memtrace_enable_set(void *data, u64 val) 2399d5171a8SRashmica Gupta { 2409d5171a8SRashmica Gupta if (memtrace_size) 2419d5171a8SRashmica Gupta return -EINVAL; 2429d5171a8SRashmica Gupta 2439d5171a8SRashmica Gupta if (!val) 2449d5171a8SRashmica Gupta return -EINVAL; 2459d5171a8SRashmica Gupta 2469d5171a8SRashmica Gupta /* Make sure size is aligned to a memory block */ 2479d5171a8SRashmica Gupta if (val & (memory_block_size_bytes() - 1)) 2489d5171a8SRashmica Gupta return -EINVAL; 2499d5171a8SRashmica Gupta 2509d5171a8SRashmica Gupta if (memtrace_init_regions_runtime(val)) 2519d5171a8SRashmica Gupta return -EINVAL; 2529d5171a8SRashmica Gupta 2539d5171a8SRashmica Gupta if (memtrace_init_debugfs()) 2549d5171a8SRashmica Gupta return -EINVAL; 2559d5171a8SRashmica Gupta 2569d5171a8SRashmica Gupta memtrace_size = val; 2579d5171a8SRashmica Gupta 2589d5171a8SRashmica Gupta return 0; 2599d5171a8SRashmica Gupta } 2609d5171a8SRashmica Gupta 2619d5171a8SRashmica Gupta static int memtrace_enable_get(void *data, u64 *val) 2629d5171a8SRashmica Gupta { 2639d5171a8SRashmica Gupta *val = memtrace_size; 2649d5171a8SRashmica Gupta return 0; 2659d5171a8SRashmica Gupta } 2669d5171a8SRashmica Gupta 2679d5171a8SRashmica Gupta DEFINE_SIMPLE_ATTRIBUTE(memtrace_init_fops, memtrace_enable_get, 2689d5171a8SRashmica Gupta memtrace_enable_set, "0x%016llx\n"); 2699d5171a8SRashmica Gupta 2709d5171a8SRashmica Gupta static int memtrace_init(void) 2719d5171a8SRashmica Gupta { 2729d5171a8SRashmica Gupta memtrace_debugfs_dir = debugfs_create_dir("memtrace", 2739d5171a8SRashmica Gupta powerpc_debugfs_root); 2749d5171a8SRashmica Gupta if (!memtrace_debugfs_dir) 2759d5171a8SRashmica Gupta return -1; 2769d5171a8SRashmica Gupta 2779d5171a8SRashmica Gupta debugfs_create_file("enable", 0600, memtrace_debugfs_dir, 2789d5171a8SRashmica Gupta NULL, &memtrace_init_fops); 2799d5171a8SRashmica Gupta 2809d5171a8SRashmica Gupta return 0; 2819d5171a8SRashmica Gupta } 2829d5171a8SRashmica Gupta machine_device_initcall(powernv, memtrace_init); 283