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