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 20static 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 67static 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 96static 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 128static 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 157static 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 183static struct notifier_block pseries_mem_nb = { 184 .notifier_call = pseries_memory_notifier, 185}; 186 187static 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} 194machine_device_initcall(pseries, pseries_memory_hotplug_init); 195