1 /* 2 * pseries Memory Hotplug infrastructure. 3 * 4 * Copyright (C) 2008 Badari Pulavarty, IBM Corporation 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #include <linux/of.h> 13 #include <linux/memblock.h> 14 #include <linux/vmalloc.h> 15 #include <linux/memory.h> 16 17 #include <asm/firmware.h> 18 #include <asm/machdep.h> 19 #include <asm/sparsemem.h> 20 21 static unsigned long get_memblock_size(void) 22 { 23 struct device_node *np; 24 unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE; 25 struct resource r; 26 27 np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory"); 28 if (np) { 29 const __be64 *size; 30 31 size = of_get_property(np, "ibm,lmb-size", NULL); 32 if (size) 33 memblock_size = be64_to_cpup(size); 34 of_node_put(np); 35 } else if (machine_is(pseries)) { 36 /* This fallback really only applies to pseries */ 37 unsigned int memzero_size = 0; 38 39 np = of_find_node_by_path("/memory@0"); 40 if (np) { 41 if (!of_address_to_resource(np, 0, &r)) 42 memzero_size = resource_size(&r); 43 of_node_put(np); 44 } 45 46 if (memzero_size) { 47 /* We now know the size of memory@0, use this to find 48 * the first memoryblock and get its size. 49 */ 50 char buf[64]; 51 52 sprintf(buf, "/memory@%x", memzero_size); 53 np = of_find_node_by_path(buf); 54 if (np) { 55 if (!of_address_to_resource(np, 0, &r)) 56 memblock_size = resource_size(&r); 57 of_node_put(np); 58 } 59 } 60 } 61 return memblock_size; 62 } 63 64 /* WARNING: This is going to override the generic definition whenever 65 * pseries is built-in regardless of what platform is active at boot 66 * time. This is fine for now as this is the only "option" and it 67 * should work everywhere. If not, we'll have to turn this into a 68 * ppc_md. callback 69 */ 70 unsigned long memory_block_size_bytes(void) 71 { 72 return get_memblock_size(); 73 } 74 75 #ifdef CONFIG_MEMORY_HOTREMOVE 76 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size) 77 { 78 unsigned long start, start_pfn; 79 struct zone *zone; 80 int ret; 81 unsigned long section; 82 unsigned long sections_to_remove; 83 84 start_pfn = base >> PAGE_SHIFT; 85 86 if (!pfn_valid(start_pfn)) { 87 memblock_remove(base, memblock_size); 88 return 0; 89 } 90 91 zone = page_zone(pfn_to_page(start_pfn)); 92 93 /* 94 * Remove section mappings and sysfs entries for the 95 * section of the memory we are removing. 96 * 97 * NOTE: Ideally, this should be done in generic code like 98 * remove_memory(). But remove_memory() gets called by writing 99 * to sysfs "state" file and we can't remove sysfs entries 100 * while writing to it. So we have to defer it to here. 101 */ 102 sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION; 103 for (section = 0; section < sections_to_remove; section++) { 104 unsigned long pfn = start_pfn + section * PAGES_PER_SECTION; 105 ret = __remove_pages(zone, pfn, PAGES_PER_SECTION); 106 if (ret) 107 return ret; 108 } 109 110 /* 111 * Update memory regions for memory remove 112 */ 113 memblock_remove(base, memblock_size); 114 115 /* 116 * Remove htab bolted mappings for this section of memory 117 */ 118 start = (unsigned long)__va(base); 119 ret = remove_section_mapping(start, start + memblock_size); 120 121 /* Ensure all vmalloc mappings are flushed in case they also 122 * hit that section of memory 123 */ 124 vm_unmap_aliases(); 125 126 return ret; 127 } 128 129 static int pseries_remove_memory(struct device_node *np) 130 { 131 const char *type; 132 const unsigned int *regs; 133 unsigned long base; 134 unsigned int lmb_size; 135 int ret = -EINVAL; 136 137 /* 138 * Check to see if we are actually removing memory 139 */ 140 type = of_get_property(np, "device_type", NULL); 141 if (type == NULL || strcmp(type, "memory") != 0) 142 return 0; 143 144 /* 145 * Find the bae address and size of the memblock 146 */ 147 regs = of_get_property(np, "reg", NULL); 148 if (!regs) 149 return ret; 150 151 base = *(unsigned long *)regs; 152 lmb_size = regs[3]; 153 154 ret = pseries_remove_memblock(base, lmb_size); 155 return ret; 156 } 157 #else 158 static inline int pseries_remove_memblock(unsigned long base, 159 unsigned int memblock_size) 160 { 161 return -EOPNOTSUPP; 162 } 163 static inline int pseries_remove_memory(struct device_node *np) 164 { 165 return -EOPNOTSUPP; 166 } 167 #endif /* CONFIG_MEMORY_HOTREMOVE */ 168 169 static int pseries_add_memory(struct device_node *np) 170 { 171 const char *type; 172 const unsigned int *regs; 173 unsigned long base; 174 unsigned int lmb_size; 175 int ret = -EINVAL; 176 177 /* 178 * Check to see if we are actually adding memory 179 */ 180 type = of_get_property(np, "device_type", NULL); 181 if (type == NULL || strcmp(type, "memory") != 0) 182 return 0; 183 184 /* 185 * Find the base and size of the memblock 186 */ 187 regs = of_get_property(np, "reg", NULL); 188 if (!regs) 189 return ret; 190 191 base = *(unsigned long *)regs; 192 lmb_size = regs[3]; 193 194 /* 195 * Update memory region to represent the memory add 196 */ 197 ret = memblock_add(base, lmb_size); 198 return (ret < 0) ? -EINVAL : 0; 199 } 200 201 static int pseries_update_drconf_memory(struct of_prop_reconfig *pr) 202 { 203 struct of_drconf_cell *new_drmem, *old_drmem; 204 unsigned long memblock_size; 205 u32 entries; 206 u32 *p; 207 int i, rc = -EINVAL; 208 209 memblock_size = get_memblock_size(); 210 if (!memblock_size) 211 return -EINVAL; 212 213 p = (u32 *)of_get_property(pr->dn, "ibm,dynamic-memory", NULL); 214 if (!p) 215 return -EINVAL; 216 217 /* The first int of the property is the number of lmb's described 218 * by the property. This is followed by an array of of_drconf_cell 219 * entries. Get the niumber of entries and skip to the array of 220 * of_drconf_cell's. 221 */ 222 entries = *p++; 223 old_drmem = (struct of_drconf_cell *)p; 224 225 p = (u32 *)pr->prop->value; 226 p++; 227 new_drmem = (struct of_drconf_cell *)p; 228 229 for (i = 0; i < entries; i++) { 230 if ((old_drmem[i].flags & DRCONF_MEM_ASSIGNED) && 231 (!(new_drmem[i].flags & DRCONF_MEM_ASSIGNED))) { 232 rc = pseries_remove_memblock(old_drmem[i].base_addr, 233 memblock_size); 234 break; 235 } else if ((!(old_drmem[i].flags & DRCONF_MEM_ASSIGNED)) && 236 (new_drmem[i].flags & DRCONF_MEM_ASSIGNED)) { 237 rc = memblock_add(old_drmem[i].base_addr, 238 memblock_size); 239 rc = (rc < 0) ? -EINVAL : 0; 240 break; 241 } 242 } 243 244 return rc; 245 } 246 247 static int pseries_memory_notifier(struct notifier_block *nb, 248 unsigned long action, void *node) 249 { 250 struct of_prop_reconfig *pr; 251 int err = 0; 252 253 switch (action) { 254 case OF_RECONFIG_ATTACH_NODE: 255 err = pseries_add_memory(node); 256 break; 257 case OF_RECONFIG_DETACH_NODE: 258 err = pseries_remove_memory(node); 259 break; 260 case OF_RECONFIG_UPDATE_PROPERTY: 261 pr = (struct of_prop_reconfig *)node; 262 if (!strcmp(pr->prop->name, "ibm,dynamic-memory")) 263 err = pseries_update_drconf_memory(pr); 264 break; 265 } 266 return notifier_from_errno(err); 267 } 268 269 static struct notifier_block pseries_mem_nb = { 270 .notifier_call = pseries_memory_notifier, 271 }; 272 273 static int __init pseries_memory_hotplug_init(void) 274 { 275 if (firmware_has_feature(FW_FEATURE_LPAR)) 276 of_reconfig_notifier_register(&pseries_mem_nb); 277 278 return 0; 279 } 280 machine_device_initcall(pseries, pseries_memory_hotplug_init); 281