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/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);