diff options
| -rw-r--r-- | Documentation/memory-hotplug.txt | 47 | ||||
| -rw-r--r-- | drivers/base/memory.c | 155 |
2 files changed, 139 insertions, 63 deletions
diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt index 57e7e9cc187..8f485d72cf2 100644 --- a/Documentation/memory-hotplug.txt +++ b/Documentation/memory-hotplug.txt @@ -126,36 +126,51 @@ config options. -------------------------------- 4 sysfs files for memory hotplug -------------------------------- -All sections have their device information under /sys/devices/system/memory as +All sections have their device information in sysfs. Each section is part of +a memory block under /sys/devices/system/memory as /sys/devices/system/memory/memoryXXX -(XXX is section id.) +(XXX is the section id.) -Now, XXX is defined as start_address_of_section / section_size. +Now, XXX is defined as (start_address_of_section / section_size) of the first +section contained in the memory block. The files 'phys_index' and +'end_phys_index' under each directory report the beginning and end section id's +for the memory block covered by the sysfs directory. It is expected that all +memory sections in this range are present and no memory holes exist in the +range. Currently there is no way to determine if there is a memory hole, but +the existence of one should not affect the hotplug capabilities of the memory +block. For example, assume 1GiB section size. A device for a memory starting at 0x100000000 is /sys/device/system/memory/memory4 (0x100000000 / 1Gib = 4) This device covers address range [0x100000000 ... 0x140000000) -Under each section, you can see 4 files. +Under each section, you can see 4 or 5 files, the end_phys_index file being +a recent addition and not present on older kernels. -/sys/devices/system/memory/memoryXXX/phys_index +/sys/devices/system/memory/memoryXXX/start_phys_index +/sys/devices/system/memory/memoryXXX/end_phys_index /sys/devices/system/memory/memoryXXX/phys_device /sys/devices/system/memory/memoryXXX/state /sys/devices/system/memory/memoryXXX/removable -'phys_index' : read-only and contains section id, same as XXX. -'state' : read-write - at read: contains online/offline state of memory. - at write: user can specify "online", "offline" command -'phys_device': read-only: designed to show the name of physical memory device. - This is not well implemented now. -'removable' : read-only: contains an integer value indicating - whether the memory section is removable or not - removable. A value of 1 indicates that the memory - section is removable and a value of 0 indicates that - it is not removable. +'phys_index' : read-only and contains section id of the first section + in the memory block, same as XXX. +'end_phys_index' : read-only and contains section id of the last section + in the memory block. +'state' : read-write + at read: contains online/offline state of memory. + at write: user can specify "online", "offline" command + which will be performed on al sections in the block. +'phys_device' : read-only: designed to show the name of physical memory + device. This is not well implemented now. +'removable' : read-only: contains an integer value indicating + whether the memory block is removable or not + removable. A value of 1 indicates that the memory + block is removable and a value of 0 indicates that + it is not removable. A memory block is removable only if + every section in the block is removable. NOTE: These directories/files appear after physical memory hotplug phase. diff --git a/drivers/base/memory.c b/drivers/base/memory.c index cafeaaf0428..0b704004258 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -30,6 +30,14 @@ static DEFINE_MUTEX(mem_sysfs_mutex); #define MEMORY_CLASS_NAME "memory" +#define MIN_MEMORY_BLOCK_SIZE (1 << SECTION_SIZE_BITS) + +static int sections_per_block; + +static inline int base_memory_block_id(int section_nr) +{ + return section_nr / sections_per_block; +} static struct sysdev_class memory_sysdev_class = { .name = MEMORY_CLASS_NAME, @@ -84,28 +92,47 @@ EXPORT_SYMBOL(unregister_memory_isolate_notifier); * register_memory - Setup a sysfs device for a memory block */ static -int register_memory(struct memory_block *memory, struct mem_section *section) +int register_memory(struct memory_block *memory) { int error; memory->sysdev.cls = &memory_sysdev_class; - memory->sysdev.id = __section_nr(section); + memory->sysdev.id = memory->phys_index / sections_per_block; error = sysdev_register(&memory->sysdev); return error; } static void -unregister_memory(struct memory_block *memory, struct mem_section *section) +unregister_memory(struct memory_block *memory) { BUG_ON(memory->sysdev.cls != &memory_sysdev_class); - BUG_ON(memory->sysdev.id != __section_nr(section)); /* drop the ref. we got in remove_memory_block() */ kobject_put(&memory->sysdev.kobj); sysdev_unregister(&memory->sysdev); } +unsigned long __weak memory_block_size_bytes(void) +{ + return MIN_MEMORY_BLOCK_SIZE; +} + +static unsigned long get_memory_block_size(void) +{ + unsigned long block_sz; + + block_sz = memory_block_size_bytes(); + + /* Validate blk_sz is a power of 2 and not less than section size */ + if ((block_sz & (block_sz - 1)) || (block_sz < MIN_MEMORY_BLOCK_SIZE)) { + WARN_ON(1); + block_sz = MIN_MEMORY_BLOCK_SIZE; + } + + return block_sz; +} + /* * use this as the physical section index that this memsection * uses. @@ -116,7 +143,7 @@ static ssize_t show_mem_phys_index(struct sys_device *dev, { struct memory_block *mem = container_of(dev, struct memory_block, sysdev); - return sprintf(buf, "%08lx\n", mem->phys_index); + return sprintf(buf, "%08lx\n", mem->phys_index / sections_per_block); } /* @@ -125,13 +152,16 @@ static ssize_t show_mem_phys_index(struct sys_device *dev, static ssize_t show_mem_removable(struct sys_device *dev, struct sysdev_attribute *attr, char *buf) { - unsigned long start_pfn; - int ret; + unsigned long i, pfn; + int ret = 1; struct memory_block *mem = container_of(dev, struct memory_block, sysdev); - start_pfn = section_nr_to_pfn(mem->phys_index); - ret = is_mem_section_removable(start_pfn, PAGES_PER_SECTION); + for (i = 0; i < sections_per_block; i++) { + pfn = section_nr_to_pfn(mem->phys_index + i); + ret &= is_mem_section_removable(pfn, PAGES_PER_SECTION); + } + return sprintf(buf, "%d\n", ret); } @@ -184,17 +214,14 @@ int memory_isolate_notify(unsigned long val, void *v) * OK to have direct references to sparsemem variables in here. */ static int -memory_block_action(struct memory_block *mem, unsigned long action) +memory_section_action(unsigned long phys_index, unsigned long action) { int i; - unsigned long psection; unsigned long start_pfn, start_paddr; struct page *first_page; int ret; - int old_state = mem->state; - psection = mem->phys_index; - first_page = pfn_to_page(psection << PFN_SECTION_SHIFT); + first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT); /* * The probe routines leave the pages reserved, just @@ -207,8 +234,8 @@ memory_block_action(struct memory_block *mem, unsigned long action) continue; printk(KERN_WARNING "section number %ld page number %d " - "not reserved, was it already online? \n", - psection, i); + "not reserved, was it already online?\n", + phys_index, i); return -EBUSY; } } @@ -219,18 +246,13 @@ memory_block_action(struct memory_block *mem, unsigned long action) ret = online_pages(start_pfn, PAGES_PER_SECTION); break; case MEM_OFFLINE: - mem->state = MEM_GOING_OFFLINE; start_paddr = page_to_pfn(first_page) << PAGE_SHIFT; ret = remove_memory(start_paddr, PAGES_PER_SECTION << PAGE_SHIFT); - if (ret) { - mem->state = old_state; - break; - } break; default: - WARN(1, KERN_WARNING "%s(%p, %ld) unknown action: %ld\n", - __func__, mem, action, action); + WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: " + "%ld\n", __func__, phys_index, action, action); ret = -EINVAL; } @@ -240,7 +262,8 @@ memory_block_action(struct memory_block *mem, unsigned long action) static int memory_block_change_state(struct memory_block *mem, unsigned long to_state, unsigned long from_state_req) { - int ret = 0; + int i, ret = 0; + mutex_lock(&mem->state_mutex); if (mem->state != from_state_req) { @@ -248,8 +271,22 @@ static int memory_block_change_state(struct memory_block *mem, goto out; } - ret = memory_block_action(mem, to_state); - if (!ret) + if (to_state == MEM_OFFLINE) + mem->state = MEM_GOING_OFFLINE; + + for (i = 0; i < sections_per_block; i++) { + ret = memory_section_action(mem->phys_index + i, to_state); + if (ret) + break; + } + + if (ret) { + for (i = 0; i < sections_per_block; i++) + memory_section_action(mem->phys_index + i, + from_state_req); + + mem->state = from_state_req; + } else mem->state = to_state; out: @@ -262,20 +299,15 @@ store_mem_state(struct sys_device *dev, struct sysdev_attribute *attr, const char *buf, size_t count) { struct memory_block *mem; - unsigned int phys_section_nr; int ret = -EINVAL; mem = container_of(dev, struct memory_block, sysdev); - phys_section_nr = mem->phys_index; - - if (!present_section_nr(phys_section_nr)) - goto out; if (!strncmp(buf, "online", min((int)count, 6))) ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE); else if(!strncmp(buf, "offline", min((int)count, 7))) ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); -out: + if (ret) return ret; return count; @@ -315,7 +347,7 @@ static ssize_t print_block_size(struct sysdev_class *class, struct sysdev_class_attribute *attr, char *buf) { - return sprintf(buf, "%lx\n", (unsigned long)PAGES_PER_SECTION * PAGE_SIZE); + return sprintf(buf, "%lx\n", get_memory_block_size()); } static SYSDEV_CLASS_ATTR(block_size_bytes, 0444, print_block_size, NULL); @@ -444,6 +476,7 @@ struct memory_block *find_memory_block_hinted(struct mem_section *section, struct sys_device *sysdev; struct memory_block *mem; char name[sizeof(MEMORY_CLASS_NAME) + 9 + 1]; + int block_id = base_memory_block_id(__section_nr(section)); kobj = hint ? &hint->sysdev.kobj : NULL; @@ -451,7 +484,7 @@ struct memory_block *find_memory_block_hinted(struct mem_section *section, * This only works because we know that section == sysdev->id * slightly redundant with sysdev_register() */ - sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, __section_nr(section)); + sprintf(&name[0], "%s%d", MEMORY_CLASS_NAME, block_id); kobj = kset_find_obj_hinted(&memory_sysdev_class.kset, name, kobj); if (!kobj) @@ -476,26 +509,27 @@ struct memory_block *find_memory_block(struct mem_section *section) return find_memory_block_hinted(section, NULL); } -static int add_memory_block(int nid, struct mem_section *section, - unsigned long state, enum mem_add_context context) +static int init_memory_block(struct memory_block **memory, + struct mem_section *section, unsigned long state) { - struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL); + struct memory_block *mem; unsigned long start_pfn; + int scn_nr; int ret = 0; + mem = kzalloc(sizeof(*mem), GFP_KERNEL); if (!mem) return -ENOMEM; - mutex_lock(&mem_sysfs_mutex); - - mem->phys_index = __section_nr(section); + scn_nr = __section_nr(section); + mem->phys_index = base_memory_block_id(scn_nr) * sections_per_block; mem->state = state; mem->section_count++; mutex_init(&mem->state_mutex); start_pfn = section_nr_to_pfn(mem->phys_index); mem->phys_device = arch_get_memory_phys_device(start_pfn); - ret = register_memory(mem, section); + ret = register_memory(mem); if (!ret) ret = mem_create_simple_file(mem, phys_index); if (!ret) @@ -504,8 +538,29 @@ static int add_memory_block(int nid, struct mem_section *section, ret = mem_create_simple_file(mem, phys_device); if (!ret) ret = mem_create_simple_file(mem, removable); + + *memory = mem; + return ret; +} + +static int add_memory_section(int nid, struct mem_section *section, + unsigned long state, enum mem_add_context context) +{ + struct memory_block *mem; + int ret = 0; + + mutex_lock(&mem_sysfs_mutex); + + mem = find_memory_block(section); + if (mem) { + mem->section_count++; + kobject_put(&mem->sysdev.kobj); + } else + ret = init_memory_block(&mem, section, state); + if (!ret) { - if (context == HOTPLUG) + if (context == HOTPLUG && + mem->section_count == sections_per_block) ret = register_mem_sect_under_node(mem, nid); } @@ -528,8 +583,10 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section, mem_remove_simple_file(mem, state); mem_remove_simple_file(mem, phys_device); mem_remove_simple_file(mem, removable); - unregister_memory(mem, section); - } + unregister_memory(mem); + kfree(mem); + } else + kobject_put(&mem->sysdev.kobj); mutex_unlock(&mem_sysfs_mutex); return 0; @@ -541,7 +598,7 @@ int remove_memory_block(unsigned long node_id, struct mem_section *section, */ int register_new_memory(int nid, struct mem_section *section) { - return add_memory_block(nid, section, MEM_OFFLINE, HOTPLUG); + return add_memory_section(nid, section, MEM_OFFLINE, HOTPLUG); } int unregister_memory_section(struct mem_section *section) @@ -560,12 +617,16 @@ int __init memory_dev_init(void) unsigned int i; int ret; int err; + unsigned long block_sz; memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops; ret = sysdev_class_register(&memory_sysdev_class); if (ret) goto out; + block_sz = get_memory_block_size(); + sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE; + /* * Create entries for memory sections that were found * during boot and have been initialized @@ -573,8 +634,8 @@ int __init memory_dev_init(void) for (i = 0; i < NR_MEM_SECTIONS; i++) { if (!present_section_nr(i)) continue; - err = add_memory_block(0, __nr_to_section(i), MEM_ONLINE, - BOOT); + err = add_memory_section(0, __nr_to_section(i), MEM_ONLINE, + BOOT); if (!ret) ret = err; } |