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