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 static unsigned long get_memblock_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 /* WARNING: This is going to override the generic definition whenever
  68  * pseries is built-in regardless of what platform is active at boot
  69  * time. This is fine for now as this is the only "option" and it
  70  * should work everywhere. If not, we'll have to turn this into a
  71  * ppc_md. callback
  72  */
  73 unsigned long memory_block_size_bytes(void)
  74 {
  75         return get_memblock_size();
  76 }
  77
  78 #ifdef CONFIG_MEMORY_HOTREMOVE
  79 static int pseries_remove_memory(u64 start, u64 size)
  80 {
  81         int ret;
  82
  83         /* Remove htab bolted mappings for this section of memory */
  84         start = (unsigned long)__va(start);
  85         ret = remove_section_mapping(start, start + size);
  86
  87         /* Ensure all vmalloc mappings are flushed in case they also
  88          * hit that section of memory
  89          */
  90         vm_unmap_aliases();
  91
  92         return ret;
  93 }
  94
  95 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
  96 {
  97         unsigned long block_sz, start_pfn;
  98         int sections_per_block;
  99         int i, nid;
 100
 101         start_pfn = base >> PAGE_SHIFT;
 102
 103         lock_device_hotplug();
 104
 105         if (!pfn_valid(start_pfn))
 106                 goto out;
 107
 108         block_sz = memory_block_size_bytes();
 109         sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE;
 110         nid = memory_add_physaddr_to_nid(base);
 111
 112         for (i = 0; i < sections_per_block; i++) {
 113                 remove_memory(nid, base, MIN_MEMORY_BLOCK_SIZE);
 114                 base += MIN_MEMORY_BLOCK_SIZE;
 115         }
 116
 117 out:
 118         /* Update memory regions for memory remove */
 119         memblock_remove(base, memblock_size);
 120         unlock_device_hotplug();
 121         return 0;
 122 }
 123
 124 static int pseries_remove_mem_node(struct device_node *np)
 125 {
 126         const char *type;
 127         const unsigned int *regs;
 128         unsigned long base;
 129         unsigned int lmb_size;
 130         int ret = -EINVAL;
 131
 132         /*
 133          * Check to see if we are actually removing memory
 134          */
 135         type = of_get_property(np, "device_type", NULL);
 136         if (type == NULL || strcmp(type, "memory") != 0)
 137                 return 0;
 138
 139         /*
 140          * Find the bae address and size of the memblock
 141          */
 142         regs = of_get_property(np, "reg", NULL);
 143         if (!regs)
 144                 return ret;
 145
 146         base = *(unsigned long *)regs;
 147         lmb_size = regs[3];
 148
 149         pseries_remove_memblock(base, lmb_size);
 150         return 0;
 151 }
 152 #else
 153 static inline int pseries_remove_memblock(unsigned long base,
 154                                           unsigned int memblock_size)
 155 {
 156         return -EOPNOTSUPP;
 157 }
 158 static inline int pseries_remove_mem_node(struct device_node *np)
 159 {
 160         return -EOPNOTSUPP;
 161 }
 162 #endif /* CONFIG_MEMORY_HOTREMOVE */
 163
 164 static int pseries_add_mem_node(struct device_node *np)
 165 {
 166         const char *type;
 167         const unsigned int *regs;
 168         unsigned long base;
 169         unsigned int lmb_size;
 170         int ret = -EINVAL;
 171
 172         /*
 173          * Check to see if we are actually adding memory
 174          */
 175         type = of_get_property(np, "device_type", NULL);
 176         if (type == NULL || strcmp(type, "memory") != 0)
 177                 return 0;
 178
 179         /*
 180          * Find the base and size of the memblock
 181          */
 182         regs = of_get_property(np, "reg", NULL);
 183         if (!regs)
 184                 return ret;
 185
 186         base = *(unsigned long *)regs;
 187         lmb_size = regs[3];
 188
 189         /*
 190          * Update memory region to represent the memory add
 191          */
 192         ret = memblock_add(base, lmb_size);
 193         return (ret < 0) ? -EINVAL : 0;
 194 }
 195
 196 static int pseries_update_drconf_memory(struct of_prop_reconfig *pr)
 197 {
 198         struct of_drconf_cell *new_drmem, *old_drmem;
 199         unsigned long memblock_size;
 200         u32 entries;
 201         u32 *p;
 202         int i, rc = -EINVAL;
 203
 204         memblock_size = get_memblock_size();
 205         if (!memblock_size)
 206                 return -EINVAL;
 207
 208         p = (u32 *)of_get_property(pr->dn, "ibm,dynamic-memory", NULL);
 209         if (!p)
 210                 return -EINVAL;
 211
 212         /* The first int of the property is the number of lmb's described
 213          * by the property. This is followed by an array of of_drconf_cell
 214          * entries. Get the niumber of entries and skip to the array of
 215          * of_drconf_cell's.
 216          */
 217         entries = *p++;
 218         old_drmem = (struct of_drconf_cell *)p;
 219
 220         p = (u32 *)pr->prop->value;
 221         p++;
 222         new_drmem = (struct of_drconf_cell *)p;
 223
 224         for (i = 0; i < entries; i++) {
 225                 if ((old_drmem[i].flags & DRCONF_MEM_ASSIGNED) &&
 226                     (!(new_drmem[i].flags & DRCONF_MEM_ASSIGNED))) {
 227                         rc = pseries_remove_memblock(old_drmem[i].base_addr,
 228                                                      memblock_size);
 229                         break;
 230                 } else if ((!(old_drmem[i].flags & DRCONF_MEM_ASSIGNED)) &&
 231                            (new_drmem[i].flags & DRCONF_MEM_ASSIGNED)) {
 232                         rc = memblock_add(old_drmem[i].base_addr,
 233                                           memblock_size);
 234                         rc = (rc < 0) ? -EINVAL : 0;
 235                         break;
 236                 }
 237         }
 238
 239         return rc;
 240 }
 241
 242 static int pseries_memory_notifier(struct notifier_block *nb,
 243                                    unsigned long action, void *node)
 244 {
 245         struct of_prop_reconfig *pr;
 246         int err = 0;
 247
 248         switch (action) {
 249         case OF_RECONFIG_ATTACH_NODE:
 250                 err = pseries_add_mem_node(node);
 251                 break;
 252         case OF_RECONFIG_DETACH_NODE:
 253                 err = pseries_remove_mem_node(node);
 254                 break;
 255         case OF_RECONFIG_UPDATE_PROPERTY:
 256                 pr = (struct of_prop_reconfig *)node;
 257                 if (!strcmp(pr->prop->name, "ibm,dynamic-memory"))
 258                         err = pseries_update_drconf_memory(pr);
 259                 break;
 260         }
 261         return notifier_from_errno(err);
 262 }
 263
 264 static struct notifier_block pseries_mem_nb = {
 265         .notifier_call = pseries_memory_notifier,
 266 };
 267
 268 static int __init pseries_memory_hotplug_init(void)
 269 {
 270         if (firmware_has_feature(FW_FEATURE_LPAR))
 271                 of_reconfig_notifier_register(&pseries_mem_nb);
 272
 273 #ifdef CONFIG_MEMORY_HOTREMOVE
 274         ppc_md.remove_memory = pseries_remove_memory;
 275 #endif
 276
 277         return 0;
 278 }
 279 machine_device_initcall(pseries, pseries_memory_hotplug_init);