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 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size) 76 { 77 unsigned long start, start_pfn; 78 struct zone *zone; 79 int ret; 80 unsigned long section; 81 unsigned long sections_to_remove; 82 83 start_pfn = base >> PAGE_SHIFT; 84 85 if (!pfn_valid(start_pfn)) { 86 memblock_remove(base, memblock_size); 87 return 0; 88 } 89 90 zone = page_zone(pfn_to_page(start_pfn)); 91 92 /* 93 * Remove section mappings and sysfs entries for the 94 * section of the memory we are removing. 95 * 96 * NOTE: Ideally, this should be done in generic code like 97 * remove_memory(). But remove_memory() gets called by writing 98 * to sysfs "state" file and we can't remove sysfs entries 99 * while writing to it. So we have to defer it to here. 100 */ 101 sections_to_remove = (memblock_size >> PAGE_SHIFT) / PAGES_PER_SECTION; 102 for (section = 0; section < sections_to_remove; section++) { 103 unsigned long pfn = start_pfn + section * PAGES_PER_SECTION; 104 ret = __remove_pages(zone, pfn, PAGES_PER_SECTION); 105 if (ret) 106 return ret; 107 } 108 109 /* 110 * Update memory regions for memory remove 111 */ 112 memblock_remove(base, memblock_size); 113 114 /* 115 * Remove htab bolted mappings for this section of memory 116 */ 117 start = (unsigned long)__va(base); 118 ret = remove_section_mapping(start, start + memblock_size); 119 120 /* Ensure all vmalloc mappings are flushed in case they also 121 * hit that section of memory 122 */ 123 vm_unmap_aliases(); 124 125 return ret; 126 } 127 128 static int pseries_remove_memory(struct device_node *np) 129 { 130 const char *type; 131 const unsigned int *regs; 132 unsigned long base; 133 unsigned int lmb_size; 134 int ret = -EINVAL; 135 136 /* 137 * Check to see if we are actually removing memory 138 */ 139 type = of_get_property(np, "device_type", NULL); 140 if (type == NULL || strcmp(type, "memory") != 0) 141 return 0; 142 143 /* 144 * Find the bae address and size of the memblock 145 */ 146 regs = of_get_property(np, "reg", NULL); 147 if (!regs) 148 return ret; 149 150 base = *(unsigned long *)regs; 151 lmb_size = regs[3]; 152 153 ret = pseries_remove_memblock(base, lmb_size); 154 return ret; 155 } 156 157 static int pseries_add_memory(struct device_node *np) 158 { 159 const char *type; 160 const unsigned int *regs; 161 unsigned long base; 162 unsigned int lmb_size; 163 int ret = -EINVAL; 164 165 /* 166 * Check to see if we are actually adding memory 167 */ 168 type = of_get_property(np, "device_type", NULL); 169 if (type == NULL || strcmp(type, "memory") != 0) 170 return 0; 171 172 /* 173 * Find the base and size of the memblock 174 */ 175 regs = of_get_property(np, "reg", NULL); 176 if (!regs) 177 return ret; 178 179 base = *(unsigned long *)regs; 180 lmb_size = regs[3]; 181 182 /* 183 * Update memory region to represent the memory add 184 */ 185 ret = memblock_add(base, lmb_size); 186 return (ret < 0) ? -EINVAL : 0; 187 } 188 189 static int pseries_update_drconf_memory(struct of_prop_reconfig *pr) 190 { 191 struct of_drconf_cell *new_drmem, *old_drmem; 192 unsigned long memblock_size; 193 u32 entries; 194 u32 *p; 195 int i, rc = -EINVAL; 196 197 memblock_size = get_memblock_size(); 198 if (!memblock_size) 199 return -EINVAL; 200 201 p = (u32 *)of_get_property(pr->dn, "ibm,dynamic-memory", NULL); 202 if (!p) 203 return -EINVAL; 204 205 /* The first int of the property is the number of lmb's described 206 * by the property. This is followed by an array of of_drconf_cell 207 * entries. Get the niumber of entries and skip to the array of 208 * of_drconf_cell's. 209 */ 210 entries = *p++; 211 old_drmem = (struct of_drconf_cell *)p; 212 213 p = (u32 *)pr->prop->value; 214 p++; 215 new_drmem = (struct of_drconf_cell *)p; 216 217 for (i = 0; i < entries; i++) { 218 if ((old_drmem[i].flags & DRCONF_MEM_ASSIGNED) && 219 (!(new_drmem[i].flags & DRCONF_MEM_ASSIGNED))) { 220 rc = pseries_remove_memblock(old_drmem[i].base_addr, 221 memblock_size); 222 break; 223 } else if ((!(old_drmem[i].flags & DRCONF_MEM_ASSIGNED)) && 224 (new_drmem[i].flags & DRCONF_MEM_ASSIGNED)) { 225 rc = memblock_add(old_drmem[i].base_addr, 226 memblock_size); 227 rc = (rc < 0) ? -EINVAL : 0; 228 break; 229 } 230 } 231 232 return rc; 233 } 234 235 static int pseries_memory_notifier(struct notifier_block *nb, 236 unsigned long action, void *node) 237 { 238 struct of_prop_reconfig *pr; 239 int err = 0; 240 241 switch (action) { 242 case OF_RECONFIG_ATTACH_NODE: 243 err = pseries_add_memory(node); 244 break; 245 case OF_RECONFIG_DETACH_NODE: 246 err = pseries_remove_memory(node); 247 break; 248 case OF_RECONFIG_UPDATE_PROPERTY: 249 pr = (struct of_prop_reconfig *)node; 250 if (!strcmp(pr->prop->name, "ibm,dynamic-memory")) 251 err = pseries_update_drconf_memory(pr); 252 break; 253 } 254 return notifier_from_errno(err); 255 } 256 257 static struct notifier_block pseries_mem_nb = { 258 .notifier_call = pseries_memory_notifier, 259 }; 260 261 static int __init pseries_memory_hotplug_init(void) 262 { 263 if (firmware_has_feature(FW_FEATURE_LPAR)) 264 of_reconfig_notifier_register(&pseries_mem_nb); 265 266 return 0; 267 } 268 machine_device_initcall(pseries, pseries_memory_hotplug_init); 269