release/src-rt-6.x.4708/linux/linux-2.6.36/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 <asm/firmware.h>
  16 #include <asm/machdep.h>
  17 #include <asm/pSeries_reconfig.h>
  18 #include <asm/sparsemem.h>
  19
  20 static int pseries_remove_memblock(unsigned long base, unsigned int memblock_size)
  21 {
  22         unsigned long start, start_pfn;
  23         struct zone *zone;
  24         int ret;
  25
  26         start_pfn = base >> PAGE_SHIFT;
  27
  28         if (!pfn_valid(start_pfn)) {
  29                 memblock_remove(base, memblock_size);
  30                 return 0;
  31         }
  32
  33         zone = page_zone(pfn_to_page(start_pfn));
  34
  35         /*
  36          * Remove section mappings and sysfs entries for the
  37          * section of the memory we are removing.
  38          *
  39          * NOTE: Ideally, this should be done in generic code like
  40          * remove_memory(). But remove_memory() gets called by writing
  41          * to sysfs "state" file and we can't remove sysfs entries
  42          * while writing to it. So we have to defer it to here.
  43          */
  44         ret = __remove_pages(zone, start_pfn, memblock_size >> PAGE_SHIFT);
  45         if (ret)
  46                 return ret;
  47
  48         /*
  49          * Update memory regions for memory remove
  50          */
  51         memblock_remove(base, memblock_size);
  52
  53         /*
  54          * Remove htab bolted mappings for this section of memory
  55          */
  56         start = (unsigned long)__va(base);
  57         ret = remove_section_mapping(start, start + memblock_size);
  58
  59         /* Ensure all vmalloc mappings are flushed in case they also
  60          * hit that section of memory
  61          */
  62         vm_unmap_aliases();
  63
  64         return ret;
  65 }
  66
  67 static int pseries_remove_memory(struct device_node *np)
  68 {
  69         const char *type;
  70         const unsigned int *regs;
  71         unsigned long base;
  72         unsigned int lmb_size;
  73         int ret = -EINVAL;
  74
  75         /*
  76          * Check to see if we are actually removing memory
  77          */
  78         type = of_get_property(np, "device_type", NULL);
  79         if (type == NULL || strcmp(type, "memory") != 0)
  80                 return 0;
  81
  82         /*
  83          * Find the bae address and size of the memblock
  84          */
  85         regs = of_get_property(np, "reg", NULL);
  86         if (!regs)
  87                 return ret;
  88
  89         base = *(unsigned long *)regs;
  90         lmb_size = regs[3];
  91
  92         ret = pseries_remove_memblock(base, lmb_size);
  93         return ret;
  94 }
  95
  96 static int pseries_add_memory(struct device_node *np)
  97 {
  98         const char *type;
  99         const unsigned int *regs;
 100         unsigned long base;
 101         unsigned int lmb_size;
 102         int ret = -EINVAL;
 103
 104         /*
 105          * Check to see if we are actually adding memory
 106          */
 107         type = of_get_property(np, "device_type", NULL);
 108         if (type == NULL || strcmp(type, "memory") != 0)
 109                 return 0;
 110
 111         /*
 112          * Find the base and size of the memblock
 113          */
 114         regs = of_get_property(np, "reg", NULL);
 115         if (!regs)
 116                 return ret;
 117
 118         base = *(unsigned long *)regs;
 119         lmb_size = regs[3];
 120
 121         /*
 122          * Update memory region to represent the memory add
 123          */
 124         ret = memblock_add(base, lmb_size);
 125         return (ret < 0) ? -EINVAL : 0;
 126 }
 127
 128 static int pseries_drconf_memory(unsigned long *base, unsigned int action)
 129 {
 130         struct device_node *np;
 131         const unsigned long *lmb_size;
 132         int rc;
 133
 134         np = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
 135         if (!np)
 136                 return -EINVAL;
 137
 138         lmb_size = of_get_property(np, "ibm,lmb-size", NULL);
 139         if (!lmb_size) {
 140                 of_node_put(np);
 141                 return -EINVAL;
 142         }
 143
 144         if (action == PSERIES_DRCONF_MEM_ADD) {
 145                 rc = memblock_add(*base, *lmb_size);
 146                 rc = (rc < 0) ? -EINVAL : 0;
 147         } else if (action == PSERIES_DRCONF_MEM_REMOVE) {
 148                 rc = pseries_remove_memblock(*base, *lmb_size);
 149         } else {
 150                 rc = -EINVAL;
 151         }
 152
 153         of_node_put(np);
 154         return rc;
 155 }
 156
 157 static int pseries_memory_notifier(struct notifier_block *nb,
 158                                 unsigned long action, void *node)
 159 {
 160         int err = NOTIFY_OK;
 161
 162         switch (action) {
 163         case PSERIES_RECONFIG_ADD:
 164                 if (pseries_add_memory(node))
 165                         err = NOTIFY_BAD;
 166                 break;
 167         case PSERIES_RECONFIG_REMOVE:
 168                 if (pseries_remove_memory(node))
 169                         err = NOTIFY_BAD;
 170                 break;
 171         case PSERIES_DRCONF_MEM_ADD:
 172         case PSERIES_DRCONF_MEM_REMOVE:
 173                 if (pseries_drconf_memory(node, action))
 174                         err = NOTIFY_BAD;
 175                 break;
 176         default:
 177                 err = NOTIFY_DONE;
 178                 break;
 179         }
 180         return err;
 181 }
 182
 183 static struct notifier_block pseries_mem_nb = {
 184         .notifier_call = pseries_memory_notifier,
 185 };
 186
 187 static int __init pseries_memory_hotplug_init(void)
 188 {
 189         if (firmware_has_feature(FW_FEATURE_LPAR))
 190                 pSeries_reconfig_notifier_register(&pseries_mem_nb);
 191
 192         return 0;
 193 }
 194 machine_device_initcall(pseries, pseries_memory_hotplug_init);