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/of_address.h> 14 #include <linux/memblock.h> 15 #include <linux/vmalloc.h> 16 #include <linux/memory.h> 17 18 #include <asm/firmware.h> 19 #include <asm/machdep.h> 20 #include <asm/prom.h> 21 #include <asm/sparsemem.h> 22 23 static unsigned long get_memblock_size(void) 24 { 25 struct device_node *np; 26 unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE; 27 struct resource r; 28 29 np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory"); 30 if (np) { 31 const __be64 *size; 32 33 size = of_get_property(np, "ibm,lmb-size", NULL); 34 if (size) 35 memblock_size = be64_to_cpup(size); 36 of_node_put(np); 37 } else if (machine_is(pseries)) { 38 /* This fallback really only applies to pseries */ 39 unsigned int memzero_size = 0; 40 41 np = of_find_node_by_path("/memory@0"); 42 if (np) { 43 if (!of_address_to_resource(np, 0, &r)) 44 memzero_size = resource_size(&r); 45 of_node_put(np); 46 } 47 48 if (memzero_size) { 49 /* We now know the size of memory@0, use this to find 50 * the first memoryblock and get its size. 51 */ 52 char buf[64]; 53 54 sprintf(buf, "/memory@%x", memzero_size); 55 np = of_find_node_by_path(buf); 56 if (np) { 57 if (!of_address_to_resource(np, 0, &r)) 58 memblock_size = resource_size(&r); 59 of_node_put(np); 60 } 61 } 62 } 63 return memblock_size; 64 } 65 66 /* WARNING: This is going to override the generic definition whenever 67 * pseries is built-in regardless of what platform is active at boot 68 * time. This is fine for now as this is the only "option" and it 69 * should work everywhere. If not, we'll have to turn this into a 70 * ppc_md. callback 71 */ 72 unsigned long memory_block_size_bytes(void) 73 { 74 return get_memblock_size(); 75 } 76 77 #ifdef CONFIG_MEMORY_HOTREMOVE 78 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size) 79 { 80 unsigned long start, start_pfn; 81 struct zone *zone; 82 int ret; 83 unsigned long section; 84 unsigned long sections_to_remove; 85 86 start_pfn = base >> PAGE_SHIFT; 87 88 if (!pfn_valid(start_pfn)) { 89 memblock_remove(base, memblock_size); 90 return 0; 91 } 92 93 zone = page_zone(pfn_to_page(start_pfn)); 94 95 /* 96 * Remove section mappings and sysfs entries for the 97 * section of the memory we are removing. 98 * 99 * NOTE: Ideally, this should be done in generic code like 100 * remove_memory(). But remove_memory() gets called by writing 101 * to sysfs "state" file and we can't remove sysfs entries 102 * while writing to it. So we have to defer it to here. 103 */ 104 sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION; 105 for (section = 0; section < sections_to_remove; section++) { 106 unsigned long pfn = start_pfn + section * PAGES_PER_SECTION; 107 ret = __remove_pages(zone, pfn, PAGES_PER_SECTION); 108 if (ret) 109 return ret; 110 } 111 112 /* 113 * Update memory regions for memory remove 114 */ 115 memblock_remove(base, memblock_size); 116 117 /* 118 * Remove htab bolted mappings for this section of memory 119 */ 120 start = (unsigned long)__va(base); 121 ret = remove_section_mapping(start, start + memblock_size); 122 123 /* Ensure all vmalloc mappings are flushed in case they also 124 * hit that section of memory 125 */ 126 vm_unmap_aliases(); 127 128 return ret; 129 } 130 131 static int pseries_remove_memory(struct device_node *np) 132 { 133 const char *type; 134 const unsigned int *regs; 135 unsigned long base; 136 unsigned int lmb_size; 137 int ret = -EINVAL; 138 139 /* 140 * Check to see if we are actually removing memory 141 */ 142 type = of_get_property(np, "device_type", NULL); 143 if (type == NULL || strcmp(type, "memory") != 0) 144 return 0; 145 146 /* 147 * Find the bae address and size of the memblock 148 */ 149 regs = of_get_property(np, "reg", NULL); 150 if (!regs) 151 return ret; 152 153 base = *(unsigned long *)regs; 154 lmb_size = regs[3]; 155 156 ret = pseries_remove_memblock(base, lmb_size); 157 return ret; 158 } 159 #else 160 static inline int pseries_remove_memblock(unsigned long base, 161 unsigned int memblock_size) 162 { 163 return -EOPNOTSUPP; 164 } 165 static inline int pseries_remove_memory(struct device_node *np) 166 { 167 return -EOPNOTSUPP; 168 } 169 #endif /* CONFIG_MEMORY_HOTREMOVE */ 170 171 static int pseries_add_memory(struct device_node *np) 172 { 173 const char *type; 174 const unsigned int *regs; 175 unsigned long base; 176 unsigned int lmb_size; 177 int ret = -EINVAL; 178 179 /* 180 * Check to see if we are actually adding memory 181 */ 182 type = of_get_property(np, "device_type", NULL); 183 if (type == NULL || strcmp(type, "memory") != 0) 184 return 0; 185 186 /* 187 * Find the base and size of the memblock 188 */ 189 regs = of_get_property(np, "reg", NULL); 190 if (!regs) 191 return ret; 192 193 base = *(unsigned long *)regs; 194 lmb_size = regs[3]; 195 196 /* 197 * Update memory region to represent the memory add 198 */ 199 ret = memblock_add(base, lmb_size); 200 return (ret < 0) ? -EINVAL : 0; 201 } 202 203 static int pseries_update_drconf_memory(struct of_prop_reconfig *pr) 204 { 205 struct of_drconf_cell *new_drmem, *old_drmem; 206 unsigned long memblock_size; 207 u32 entries; 208 u32 *p; 209 int i, rc = -EINVAL; 210 211 memblock_size = get_memblock_size(); 212 if (!memblock_size) 213 return -EINVAL; 214 215 p = (u32 *)of_get_property(pr->dn, "ibm,dynamic-memory", NULL); 216 if (!p) 217 return -EINVAL; 218 219 /* The first int of the property is the number of lmb's described 220 * by the property. This is followed by an array of of_drconf_cell 221 * entries. Get the niumber of entries and skip to the array of 222 * of_drconf_cell's. 223 */ 224 entries = *p++; 225 old_drmem = (struct of_drconf_cell *)p; 226 227 p = (u32 *)pr->prop->value; 228 p++; 229 new_drmem = (struct of_drconf_cell *)p; 230 231 for (i = 0; i < entries; i++) { 232 if ((old_drmem[i].flags & DRCONF_MEM_ASSIGNED) && 233 (!(new_drmem[i].flags & DRCONF_MEM_ASSIGNED))) { 234 rc = pseries_remove_memblock(old_drmem[i].base_addr, 235 memblock_size); 236 break; 237 } else if ((!(old_drmem[i].flags & DRCONF_MEM_ASSIGNED)) && 238 (new_drmem[i].flags & DRCONF_MEM_ASSIGNED)) { 239 rc = memblock_add(old_drmem[i].base_addr, 240 memblock_size); 241 rc = (rc < 0) ? -EINVAL : 0; 242 break; 243 } 244 } 245 246 return rc; 247 } 248 249 static int pseries_memory_notifier(struct notifier_block *nb, 250 unsigned long action, void *node) 251 { 252 struct of_prop_reconfig *pr; 253 int err = 0; 254 255 switch (action) { 256 case OF_RECONFIG_ATTACH_NODE: 257 err = pseries_add_memory(node); 258 break; 259 case OF_RECONFIG_DETACH_NODE: 260 err = pseries_remove_memory(node); 261 break; 262 case OF_RECONFIG_UPDATE_PROPERTY: 263 pr = (struct of_prop_reconfig *)node; 264 if (!strcmp(pr->prop->name, "ibm,dynamic-memory")) 265 err = pseries_update_drconf_memory(pr); 266 break; 267 } 268 return notifier_from_errno(err); 269 } 270 271 static struct notifier_block pseries_mem_nb = { 272 .notifier_call = pseries_memory_notifier, 273 }; 274 275 static int __init pseries_memory_hotplug_init(void) 276 { 277 if (firmware_has_feature(FW_FEATURE_LPAR)) 278 of_reconfig_notifier_register(&pseries_mem_nb); 279 280 return 0; 281 } 282 machine_device_initcall(pseries, pseries_memory_hotplug_init); 283