| Badari Pulavarty | 57b5392 | 2008-04-18 13:33:50 -0700 | [diff] [blame^] | 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 <asm/firmware.h> |
| 14 | #include <asm/machdep.h> |
| 15 | #include <asm/pSeries_reconfig.h> |
| 16 | |
| 17 | static int pseries_remove_memory(struct device_node *np) |
| 18 | { |
| 19 | const char *type; |
| 20 | const unsigned int *my_index; |
| 21 | const unsigned int *regs; |
| 22 | u64 start_pfn, start; |
| 23 | struct zone *zone; |
| 24 | int ret = -EINVAL; |
| 25 | |
| 26 | /* |
| 27 | * Check to see if we are actually removing memory |
| 28 | */ |
| 29 | type = of_get_property(np, "device_type", NULL); |
| 30 | if (type == NULL || strcmp(type, "memory") != 0) |
| 31 | return 0; |
| 32 | |
| 33 | /* |
| 34 | * Find the memory index and size of the removing section |
| 35 | */ |
| 36 | my_index = of_get_property(np, "ibm,my-drc-index", NULL); |
| 37 | if (!my_index) |
| 38 | return ret; |
| 39 | |
| 40 | regs = of_get_property(np, "reg", NULL); |
| 41 | if (!regs) |
| 42 | return ret; |
| 43 | |
| 44 | start_pfn = section_nr_to_pfn(*my_index & 0xffff); |
| 45 | zone = page_zone(pfn_to_page(start_pfn)); |
| 46 | |
| 47 | /* |
| 48 | * Remove section mappings and sysfs entries for the |
| 49 | * section of the memory we are removing. |
| 50 | * |
| 51 | * NOTE: Ideally, this should be done in generic code like |
| 52 | * remove_memory(). But remove_memory() gets called by writing |
| 53 | * to sysfs "state" file and we can't remove sysfs entries |
| 54 | * while writing to it. So we have to defer it to here. |
| 55 | */ |
| 56 | ret = __remove_pages(zone, start_pfn, regs[3] >> PAGE_SHIFT); |
| 57 | if (ret) |
| 58 | return ret; |
| 59 | |
| 60 | /* |
| 61 | * Remove htab bolted mappings for this section of memory |
| 62 | */ |
| 63 | start = (unsigned long)__va(start_pfn << PAGE_SHIFT); |
| 64 | ret = remove_section_mapping(start, start + regs[3]); |
| 65 | return ret; |
| 66 | } |
| 67 | |
| 68 | static int pseries_memory_notifier(struct notifier_block *nb, |
| 69 | unsigned long action, void *node) |
| 70 | { |
| 71 | int err = NOTIFY_OK; |
| 72 | |
| 73 | switch (action) { |
| 74 | case PSERIES_RECONFIG_ADD: |
| 75 | break; |
| 76 | case PSERIES_RECONFIG_REMOVE: |
| 77 | if (pseries_remove_memory(node)) |
| 78 | err = NOTIFY_BAD; |
| 79 | break; |
| 80 | default: |
| 81 | err = NOTIFY_DONE; |
| 82 | break; |
| 83 | } |
| 84 | return err; |
| 85 | } |
| 86 | |
| 87 | static struct notifier_block pseries_mem_nb = { |
| 88 | .notifier_call = pseries_memory_notifier, |
| 89 | }; |
| 90 | |
| 91 | static int __init pseries_memory_hotplug_init(void) |
| 92 | { |
| 93 | if (firmware_has_feature(FW_FEATURE_LPAR)) |
| 94 | pSeries_reconfig_notifier_register(&pseries_mem_nb); |
| 95 | |
| 96 | return 0; |
| 97 | } |
| 98 | machine_device_initcall(pseries, pseries_memory_hotplug_init); |