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