arch/powerpc/platforms/pseries/hotplug-memory.c

   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 #include <linux/memory_hotplug.h>
  18
  19 #include <asm/firmware.h>
  20 #include <asm/machdep.h>
  21 #include <asm/prom.h>
  22 #include <asm/sparsemem.h>
  23 #include "pseries.h"
  24
  25 unsigned long pseries_memory_block_size(void)
  26 {
  27         struct device_node *np;
  28         unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
  29         struct resource r;
  30
  31         np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
  32         if (np) {
  33                 const __be64 *size;
  34
  35                 size = of_get_property(np, "ibm,lmb-size", NULL);
  36                 if (size)
  37                         memblock_size = be64_to_cpup(size);
  38                 of_node_put(np);
  39         } else  if (machine_is(pseries)) {
  40                 /* This fallback really only applies to pseries */
  41                 unsigned int memzero_size = 0;
  42
  43                 np = of_find_node_by_path("/memory@0");
  44                 if (np) {
  45                         if (!of_address_to_resource(np, 0, &r))
  46                                 memzero_size = resource_size(&r);
  47                         of_node_put(np);
  48                 }
  49
  50                 if (memzero_size) {
  51                         /* We now know the size of memory@0, use this to find
  52                          * the first memoryblock and get its size.
  53                          */
  54                         char buf[64];
  55
  56                         sprintf(buf, "/memory@%x", memzero_size);
  57                         np = of_find_node_by_path(buf);
  58                         if (np) {
  59                                 if (!of_address_to_resource(np, 0, &r))
  60                                         memblock_size = resource_size(&r);
  61                                 of_node_put(np);
  62                         }
  63                 }
  64         }
  65         return memblock_size;
  66 }
  67
  68 #ifdef CONFIG_MEMORY_HOTREMOVE
  69 static int pseries_remove_memory(u64 start, u64 size)
  70 {
  71         int ret;
  72
  73         /* Remove htab bolted mappings for this section of memory */
  74         start = (unsigned long)__va(start);
  75         ret = remove_section_mapping(start, start + size);
  76
  77         /* Ensure all vmalloc mappings are flushed in case they also
  78          * hit that section of memory
  79          */
  80         vm_unmap_aliases();
  81
  82         return ret;
  83 }
  84
  85 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
  86 {
  87         unsigned long block_sz, start_pfn;
  88         int sections_per_block;
  89         int i, nid;
  90
  91         start_pfn = base >> PAGE_SHIFT;
  92
  93         lock_device_hotplug();
  94
  95         if (!pfn_valid(start_pfn))
  96                 goto out;
  97
  98         block_sz = pseries_memory_block_size();
  99         sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
 100         nid = memory_add_physaddr_to_nid(base);
 101
 102         for (i = 0; i < sections_per_block; i++) {
 103                 remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
 104                 base += MIN_MEMORY_BLOCK_SIZE;
 105         }
 106
 107 out:
 108         /* Update memory regions for memory remove */
 109         memblock_remove(base, memblock_size);
 110         unlock_device_hotplug();
 111         return 0;
 112 }
 113
 114 static int pseries_remove_mem_node(struct device_node *np)
 115 {
 116         const char *type;
 117         const __be32 *regs;
 118         unsigned long base;
 119         unsigned int lmb_size;
 120         int ret = -EINVAL;
 121
 122         /*
 123          * Check to see if we are actually removing memory
 124          */
 125         type = of_get_property(np, "device_type", NULL);
 126         if (type == NULL || strcmp(type, "memory") != 0)
 127                 return 0;
 128
 129         /*
 130          * Find the base address and size of the memblock
 131          */
 132         regs = of_get_property(np, "reg", NULL);
 133         if (!regs)
 134                 return ret;
 135
 136         base = be64_to_cpu(*(unsigned long *)regs);
 137         lmb_size = be32_to_cpu(regs[3]);
 138
 139         pseries_remove_memblock(base, lmb_size);
 140         return 0;
 141 }
 142 #else
 143 static inline int pseries_remove_memblock(unsigned long base,
 144                                           unsigned int memblock_size)
 145 {
 146         return -EOPNOTSUPP;
 147 }
 148 static inline int pseries_remove_mem_node(struct device_node *np)
 149 {
 150         return 0;
 151 }
 152 #endif /* CONFIG_MEMORY_HOTREMOVE */
 153
 154 static int pseries_add_mem_node(struct device_node *np)
 155 {
 156         const char *type;
 157         const __be32 *regs;
 158         unsigned long base;
 159         unsigned int lmb_size;
 160         int ret = -EINVAL;
 161
 162         /*
 163          * Check to see if we are actually adding memory
 164          */
 165         type = of_get_property(np, "device_type", NULL);
 166         if (type == NULL || strcmp(type, "memory") != 0)
 167                 return 0;
 168
 169         /*
 170          * Find the base and size of the memblock
 171          */
 172         regs = of_get_property(np, "reg", NULL);
 173         if (!regs)
 174                 return ret;
 175
 176         base = be64_to_cpu(*(unsigned long *)regs);
 177         lmb_size = be32_to_cpu(regs[3]);
 178
 179         /*
 180          * Update memory region to represent the memory add
 181          */
 182         ret = memblock_add(base, lmb_size);
 183         return (ret < 0) ? -EINVAL : 0;
 184 }
 185
 186 static int pseries_update_drconf_memory(struct of_prop_reconfig *pr)
 187 {
 188         struct of_drconf_cell *new_drmem, *old_drmem;
 189         unsigned long memblock_size;
 190         u32 entries;
 191         __be32 *p;
 192         int i, rc = -EINVAL;
 193
 194         memblock_size = pseries_memory_block_size();
 195         if (!memblock_size)
 196                 return -EINVAL;
 197
 198         p = (__be32 *) pr->old_prop->value;
 199         if (!p)
 200                 return -EINVAL;
 201
 202         /* The first int of the property is the number of lmb's described
 203          * by the property. This is followed by an array of of_drconf_cell
 204          * entries. Get the number of entries and skip to the array of
 205          * of_drconf_cell's.
 206          */
 207         entries = be32_to_cpu(*p++);
 208         old_drmem = (struct of_drconf_cell *)p;
 209
 210         p = (__be32 *)pr->prop->value;
 211         p++;
 212         new_drmem = (struct of_drconf_cell *)p;
 213
 214         for (i = 0; i < entries; i++) {
 215                 if ((be32_to_cpu(old_drmem[i].flags) & DRCONF_MEM_ASSIGNED) &&
 216                     (!(be32_to_cpu(new_drmem[i].flags) & DRCONF_MEM_ASSIGNED))) {
 217                         rc = pseries_remove_memblock(
 218                                 be64_to_cpu(old_drmem[i].base_addr),
 219                                                      memblock_size);
 220                         break;
 221                 } else if ((!(be32_to_cpu(old_drmem[i].flags) &
 222                             DRCONF_MEM_ASSIGNED)) &&
 223                             (be32_to_cpu(new_drmem[i].flags) &
 224                             DRCONF_MEM_ASSIGNED)) {
 225                         rc = memblock_add(be64_to_cpu(old_drmem[i].base_addr),
 226                                           memblock_size);
 227                         rc = (rc < 0) ? -EINVAL : 0;
 228                         break;
 229                 }
 230         }
 231         return rc;
 232 }
 233
 234 static int pseries_memory_notifier(struct notifier_block *nb,
 235                                    unsigned long action, void *node)
 236 {
 237         struct of_prop_reconfig *pr;
 238         int err = 0;
 239
 240         switch (action) {
 241         case OF_RECONFIG_ATTACH_NODE:
 242                 err = pseries_add_mem_node(node);
 243                 break;
 244         case OF_RECONFIG_DETACH_NODE:
 245                 err = pseries_remove_mem_node(node);
 246                 break;
 247         case OF_RECONFIG_UPDATE_PROPERTY:
 248                 pr = (struct of_prop_reconfig *)node;
 249                 if (!strcmp(pr->prop->name, "ibm,dynamic-memory"))
 250                         err = pseries_update_drconf_memory(pr);
 251                 break;
 252         }
 253         return notifier_from_errno(err);
 254 }
 255
 256 static struct notifier_block pseries_mem_nb = {
 257         .notifier_call = pseries_memory_notifier,
 258 };
 259
 260 static int __init pseries_memory_hotplug_init(void)
 261 {
 262         if (firmware_has_feature(FW_FEATURE_LPAR))
 263                 of_reconfig_notifier_register(&pseries_mem_nb);
 264
 265 #ifdef CONFIG_MEMORY_HOTREMOVE
 266         ppc_md.remove_memory = pseries_remove_memory;
 267 #endif
 268
 269         return 0;
 270 }
 271 machine_device_initcall(pseries, pseries_memory_hotplug_init);