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/memory.h>
  16 #include <linux/memory_hotplug.h>
  17
  18 #include <asm/firmware.h>
  19 #include <asm/machdep.h>
  20 #include <asm/prom.h>
  21 #include <asm/sparsemem.h>
  22 #include "pseries.h"
  23
  24 unsigned long pseries_memory_block_size(void)
  25 {
  26         struct device_node *np;
  27         unsigned int memblock_size = MIN_MEMORY_BLOCK_SIZE;
  28         struct resource r;
  29
  30         np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
  31         if (np) {
  32                 const __be64 *size;
  33
  34                 size = of_get_property(np, "ibm,lmb-size", NULL);
  35                 if (size)
  36                         memblock_size = be64_to_cpup(size);
  37                 of_node_put(np);
  38         } else  if (machine_is(pseries)) {
  39                 /* This fallback really only applies to pseries */
  40                 unsigned int memzero_size = 0;
  41
  42                 np = of_find_node_by_path("/memory@0");
  43                 if (np) {
  44                         if (!of_address_to_resource(np, 0, &r))
  45                                 memzero_size = resource_size(&r);
  46                         of_node_put(np);
  47                 }
  48
  49                 if (memzero_size) {
  50                         /* We now know the size of memory@0, use this to find
  51                          * the first memoryblock and get its size.
  52                          */
  53                         char buf[64];
  54
  55                         sprintf(buf, "/memory@%x", memzero_size);
  56                         np = of_find_node_by_path(buf);
  57                         if (np) {
  58                                 if (!of_address_to_resource(np, 0, &r))
  59                                         memblock_size = resource_size(&r);
  60                                 of_node_put(np);
  61                         }
  62                 }
  63         }
  64         return memblock_size;
  65 }
  66
  67 #ifdef CONFIG_MEMORY_HOTREMOVE
  68 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
  69 {
  70         unsigned long block_sz, start_pfn;
  71         int sections_per_block;
  72         int i, nid;
  73
  74         start_pfn = base >> PAGE_SHIFT;
  75
  76         lock_device_hotplug();
  77
  78         if (!pfn_valid(start_pfn))
  79                 goto out;
  80
  81         block_sz = pseries_memory_block_size();
  82         sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
  83         nid = memory_add_physaddr_to_nid(base);
  84
  85         for (i = 0; i < sections_per_block; i++) {
  86                 remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
  87                 base += MIN_MEMORY_BLOCK_SIZE;
  88         }
  89
  90 out:
  91         /* Update memory regions for memory remove */
  92         memblock_remove(base, memblock_size);
  93         unlock_device_hotplug();
  94         return 0;
  95 }
  96
  97 static int pseries_remove_mem_node(struct device_node *np)
  98 {
  99         const char *type;
 100         const __be32 *regs;
 101         unsigned long base;
 102         unsigned int lmb_size;
 103         int ret = -EINVAL;
 104
 105         /*
 106          * Check to see if we are actually removing memory
 107          */
 108         type = of_get_property(np, "device_type", NULL);
 109         if (type == NULL || strcmp(type, "memory") != 0)
 110                 return 0;
 111
 112         /*
 113          * Find the base address and size of the memblock
 114          */
 115         regs = of_get_property(np, "reg", NULL);
 116         if (!regs)
 117                 return ret;
 118
 119         base = be64_to_cpu(*(unsigned long *)regs);
 120         lmb_size = be32_to_cpu(regs[3]);
 121
 122         pseries_remove_memblock(base, lmb_size);
 123         return 0;
 124 }
 125 #else
 126 static inline int pseries_remove_memblock(unsigned long base,
 127                                           unsigned int memblock_size)
 128 {
 129         return -EOPNOTSUPP;
 130 }
 131 static inline int pseries_remove_mem_node(struct device_node *np)
 132 {
 133         return 0;
 134 }
 135 #endif /* CONFIG_MEMORY_HOTREMOVE */
 136
 137 static int pseries_add_mem_node(struct device_node *np)
 138 {
 139         const char *type;
 140         const __be32 *regs;
 141         unsigned long base;
 142         unsigned int lmb_size;
 143         int ret = -EINVAL;
 144
 145         /*
 146          * Check to see if we are actually adding memory
 147          */
 148         type = of_get_property(np, "device_type", NULL);
 149         if (type == NULL || strcmp(type, "memory") != 0)
 150                 return 0;
 151
 152         /*
 153          * Find the base and size of the memblock
 154          */
 155         regs = of_get_property(np, "reg", NULL);
 156         if (!regs)
 157                 return ret;
 158
 159         base = be64_to_cpu(*(unsigned long *)regs);
 160         lmb_size = be32_to_cpu(regs[3]);
 161
 162         /*
 163          * Update memory region to represent the memory add
 164          */
 165         ret = memblock_add(base, lmb_size);
 166         return (ret < 0) ? -EINVAL : 0;
 167 }
 168
 169 static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
 170 {
 171         struct of_drconf_cell *new_drmem, *old_drmem;
 172         unsigned long memblock_size;
 173         u32 entries;
 174         __be32 *p;
 175         int i, rc = -EINVAL;
 176
 177         memblock_size = pseries_memory_block_size();
 178         if (!memblock_size)
 179                 return -EINVAL;
 180
 181         p = (__be32 *) pr->old_prop->value;
 182         if (!p)
 183                 return -EINVAL;
 184
 185         /* The first int of the property is the number of lmb's described
 186          * by the property. This is followed by an array of of_drconf_cell
 187          * entries. Get the number of entries and skip to the array of
 188          * of_drconf_cell's.
 189          */
 190         entries = be32_to_cpu(*p++);
 191         old_drmem = (struct of_drconf_cell *)p;
 192
 193         p = (__be32 *)pr->prop->value;
 194         p++;
 195         new_drmem = (struct of_drconf_cell *)p;
 196
 197         for (i = 0; i < entries; i++) {
 198                 if ((be32_to_cpu(old_drmem[i].flags) & DRCONF_MEM_ASSIGNED) &&
 199                     (!(be32_to_cpu(new_drmem[i].flags) & DRCONF_MEM_ASSIGNED))) {
 200                         rc = pseries_remove_memblock(
 201                                 be64_to_cpu(old_drmem[i].base_addr),
 202                                                      memblock_size);
 203                         break;
 204                 } else if ((!(be32_to_cpu(old_drmem[i].flags) &
 205                             DRCONF_MEM_ASSIGNED)) &&
 206                             (be32_to_cpu(new_drmem[i].flags) &
 207                             DRCONF_MEM_ASSIGNED)) {
 208                         rc = memblock_add(be64_to_cpu(old_drmem[i].base_addr),
 209                                           memblock_size);
 210                         rc = (rc < 0) ? -EINVAL : 0;
 211                         break;
 212                 }
 213         }
 214         return rc;
 215 }
 216
 217 static int pseries_memory_notifier(struct notifier_block *nb,
 218                                    unsigned long action, void *data)
 219 {
 220         struct of_reconfig_data *rd = data;
 221         int err = 0;
 222
 223         switch (action) {
 224         case OF_RECONFIG_ATTACH_NODE:
 225                 err = pseries_add_mem_node(rd->dn);
 226                 break;
 227         case OF_RECONFIG_DETACH_NODE:
 228                 err = pseries_remove_mem_node(rd->dn);
 229                 break;
 230         case OF_RECONFIG_UPDATE_PROPERTY:
 231                 if (!strcmp(rd->prop->name, "ibm,dynamic-memory"))
 232                         err = pseries_update_drconf_memory(rd);
 233                 break;
 234         }
 235         return notifier_from_errno(err);
 236 }
 237
 238 static struct notifier_block pseries_mem_nb = {
 239         .notifier_call = pseries_memory_notifier,
 240 };
 241
 242 static int __init pseries_memory_hotplug_init(void)
 243 {
 244         if (firmware_has_feature(FW_FEATURE_LPAR))
 245                 of_reconfig_notifier_register(&pseries_mem_nb);
 246
 247         return 0;
 248 }
 249 machine_device_initcall(pseries, pseries_memory_hotplug_init);