1 files changed, 476 insertions, 0 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
new file mode 100644
index 0000000..5260e9e
--- /dev/null
+++ b/drivers/base/memory.c
@@ -0,0 +1,476 @@
+/*
+ * drivers/base/memory.c - basic Memory class support
+ *
+ * Written by Matt Tolentino <matthew.e.tolentino@intel.com>
+ *            Dave Hansen <haveblue@us.ibm.com>
+ *
+ * This file provides the necessary infrastructure to represent
+ * a SPARSEMEM-memory-model system's physical memory in /sysfs.
+ * All arch-independent code that assumes MEMORY_HOTPLUG requires
+ * SPARSEMEM should be contained here, or in mm/memory_hotplug.c.
+ */
+
+#include <linux/sysdev.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/topology.h>
+#include <linux/capability.h>
+#include <linux/device.h>
+#include <linux/memory.h>
+#include <linux/kobject.h>
+#include <linux/memory_hotplug.h>
+#include <linux/mm.h>
+#include <linux/mutex.h>
+#include <linux/stat.h>
+
+#include <asm/atomic.h>
+#include <asm/uaccess.h>
+
+#define MEMORY_CLASS_NAME	"memory"
+
+static struct sysdev_class memory_sysdev_class = {
+	.name = MEMORY_CLASS_NAME,
+};
+
+static const char *memory_uevent_name(struct kset *kset, struct kobject *kobj)
+{
+	return MEMORY_CLASS_NAME;
+}
+
+static int memory_uevent(struct kset *kset, struct kobject *obj, struct kobj_uevent_env *env)
+{
+	int retval = 0;
+
+	return retval;
+}
+
+static struct kset_uevent_ops memory_uevent_ops = {
+	.name		= memory_uevent_name,
+	.uevent		= memory_uevent,
+};
+
+static BLOCKING_NOTIFIER_HEAD(memory_chain);
+
+int register_memory_notifier(struct notifier_block *nb)
+{
+        return blocking_notifier_chain_register(&memory_chain, nb);
+}
+EXPORT_SYMBOL(register_memory_notifier);
+
+void unregister_memory_notifier(struct notifier_block *nb)
+{
+        blocking_notifier_chain_unregister(&memory_chain, nb);
+}
+EXPORT_SYMBOL(unregister_memory_notifier);
+
+/*
+ * register_memory - Setup a sysfs device for a memory block
+ */
+static
+int register_memory(struct memory_block *memory, struct mem_section *section)
+{
+	int error;
+
+	memory->sysdev.cls = &memory_sysdev_class;
+	memory->sysdev.id = __section_nr(section);
+
+	error = sysdev_register(&memory->sysdev);
+	return error;
+}
+
+static void
+unregister_memory(struct memory_block *memory, struct mem_section *section)
+{
+	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);
+}
+
+/*
+ * use this as the physical section index that this memsection
+ * uses.
+ */
+
+static ssize_t show_mem_phys_index(struct sys_device *dev,
+			struct sysdev_attribute *attr, char *buf)
+{
+	struct memory_block *mem =
+		container_of(dev, struct memory_block, sysdev);
+	return sprintf(buf, "%08lx\n", mem->phys_index);
+}
+
+/*
+ * Show whether the section of memory is likely to be hot-removable
+ */
+static ssize_t show_mem_removable(struct sys_device *dev,
+			struct sysdev_attribute *attr, char *buf)
+{
+	unsigned long start_pfn;
+	int ret;
+	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);
+	return sprintf(buf, "%d\n", ret);
+}
+
+/*
+ * online, offline, going offline, etc.
+ */
+static ssize_t show_mem_state(struct sys_device *dev,
+			struct sysdev_attribute *attr, char *buf)
+{
+	struct memory_block *mem =
+		container_of(dev, struct memory_block, sysdev);
+	ssize_t len = 0;
+
+	/*
+	 * We can probably put these states in a nice little array
+	 * so that they're not open-coded
+	 */
+	switch (mem->state) {
+		case MEM_ONLINE:
+			len = sprintf(buf, "online\n");
+			break;
+		case MEM_OFFLINE:
+			len = sprintf(buf, "offline\n");
+			break;
+		case MEM_GOING_OFFLINE:
+			len = sprintf(buf, "going-offline\n");
+			break;
+		default:
+			len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
+					mem->state);
+			WARN_ON(1);
+			break;
+	}
+
+	return len;
+}
+
+int memory_notify(unsigned long val, void *v)
+{
+	return blocking_notifier_call_chain(&memory_chain, val, v);
+}
+
+/*
+ * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
+ * OK to have direct references to sparsemem variables in here.
+ */
+static int
+memory_block_action(struct memory_block *mem, 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);
+
+	/*
+	 * The probe routines leave the pages reserved, just
+	 * as the bootmem code does.  Make sure they're still
+	 * that way.
+	 */
+	if (action == MEM_ONLINE) {
+		for (i = 0; i < PAGES_PER_SECTION; i++) {
+			if (PageReserved(first_page+i))
+				continue;
+
+			printk(KERN_WARNING "section number %ld page number %d "
+				"not reserved, was it already online? \n",
+				psection, i);
+			return -EBUSY;
+		}
+	}
+
+	switch (action) {
+		case MEM_ONLINE:
+			start_pfn = page_to_pfn(first_page);
+			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);
+			ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static int memory_block_change_state(struct memory_block *mem,
+		unsigned long to_state, unsigned long from_state_req)
+{
+	int ret = 0;
+	mutex_lock(&mem->state_mutex);
+
+	if (mem->state != from_state_req) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = memory_block_action(mem, to_state);
+	if (!ret)
+		mem->state = to_state;
+
+out:
+	mutex_unlock(&mem->state_mutex);
+	return ret;
+}
+
+static ssize_t
+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;
+}
+
+/*
+ * phys_device is a bad name for this.  What I really want
+ * is a way to differentiate between memory ranges that
+ * are part of physical devices that constitute
+ * a complete removable unit or fru.
+ * i.e. do these ranges belong to the same physical device,
+ * s.t. if I offline all of these sections I can then
+ * remove the physical device?
+ */
+static ssize_t show_phys_device(struct sys_device *dev,
+				struct sysdev_attribute *attr, char *buf)
+{
+	struct memory_block *mem =
+		container_of(dev, struct memory_block, sysdev);
+	return sprintf(buf, "%d\n", mem->phys_device);
+}
+
+static SYSDEV_ATTR(phys_index, 0444, show_mem_phys_index, NULL);
+static SYSDEV_ATTR(state, 0644, show_mem_state, store_mem_state);
+static SYSDEV_ATTR(phys_device, 0444, show_phys_device, NULL);
+static SYSDEV_ATTR(removable, 0444, show_mem_removable, NULL);
+
+#define mem_create_simple_file(mem, attr_name)	\
+	sysdev_create_file(&mem->sysdev, &attr_##attr_name)
+#define mem_remove_simple_file(mem, attr_name)	\
+	sysdev_remove_file(&mem->sysdev, &attr_##attr_name)
+
+/*
+ * Block size attribute stuff
+ */
+static ssize_t
+print_block_size(struct class *class, char *buf)
+{
+	return sprintf(buf, "%lx\n", (unsigned long)PAGES_PER_SECTION * PAGE_SIZE);
+}
+
+static CLASS_ATTR(block_size_bytes, 0444, print_block_size, NULL);
+
+static int block_size_init(void)
+{
+	return sysfs_create_file(&memory_sysdev_class.kset.kobj,
+				&class_attr_block_size_bytes.attr);
+}
+
+/*
+ * Some architectures will have custom drivers to do this, and
+ * will not need to do it from userspace.  The fake hot-add code
+ * as well as ppc64 will do all of their discovery in userspace
+ * and will require this interface.
+ */
+#ifdef CONFIG_ARCH_MEMORY_PROBE
+static ssize_t
+memory_probe_store(struct class *class, const char *buf, size_t count)
+{
+	u64 phys_addr;
+	int nid;
+	int ret;
+
+	phys_addr = simple_strtoull(buf, NULL, 0);
+
+	nid = memory_add_physaddr_to_nid(phys_addr);
+	ret = add_memory(nid, phys_addr, PAGES_PER_SECTION << PAGE_SHIFT);
+
+	if (ret)
+		count = ret;
+
+	return count;
+}
+static CLASS_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
+
+static int memory_probe_init(void)
+{
+	return sysfs_create_file(&memory_sysdev_class.kset.kobj,
+				&class_attr_probe.attr);
+}
+#else
+static inline int memory_probe_init(void)
+{
+	return 0;
+}
+#endif
+
+/*
+ * Note that phys_device is optional.  It is here to allow for
+ * differentiation between which *physical* devices each
+ * section belongs to...
+ */
+
+static int add_memory_block(unsigned long node_id, struct mem_section *section,
+		     unsigned long state, int phys_device)
+{
+	struct memory_block *mem = kzalloc(sizeof(*mem), GFP_KERNEL);
+	int ret = 0;
+
+	if (!mem)
+		return -ENOMEM;
+
+	mem->phys_index = __section_nr(section);
+	mem->state = state;
+	mutex_init(&mem->state_mutex);
+	mem->phys_device = phys_device;
+
+	ret = register_memory(mem, section);
+	if (!ret)
+		ret = mem_create_simple_file(mem, phys_index);
+	if (!ret)
+		ret = mem_create_simple_file(mem, state);
+	if (!ret)
+		ret = mem_create_simple_file(mem, phys_device);
+	if (!ret)
+		ret = mem_create_simple_file(mem, removable);
+
+	return ret;
+}
+
+/*
+ * For now, we have a linear search to go find the appropriate
+ * memory_block corresponding to a particular phys_index. If
+ * this gets to be a real problem, we can always use a radix
+ * tree or something here.
+ *
+ * This could be made generic for all sysdev classes.
+ */
+static struct memory_block *find_memory_block(struct mem_section *section)
+{
+	struct kobject *kobj;
+	struct sys_device *sysdev;
+	struct memory_block *mem;
+	char name[sizeof(MEMORY_CLASS_NAME) + 9 + 1];
+
+	/*
+	 * 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));
+
+	kobj = kset_find_obj(&memory_sysdev_class.kset, name);
+	if (!kobj)
+		return NULL;
+
+	sysdev = container_of(kobj, struct sys_device, kobj);
+	mem = container_of(sysdev, struct memory_block, sysdev);
+
+	return mem;
+}
+
+int remove_memory_block(unsigned long node_id, struct mem_section *section,
+		int phys_device)
+{
+	struct memory_block *mem;
+
+	mem = find_memory_block(section);
+	mem_remove_simple_file(mem, phys_index);
+	mem_remove_simple_file(mem, state);
+	mem_remove_simple_file(mem, phys_device);
+	mem_remove_simple_file(mem, removable);
+	unregister_memory(mem, section);
+
+	return 0;
+}
+
+/*
+ * need an interface for the VM to add new memory regions,
+ * but without onlining it.
+ */
+int register_new_memory(struct mem_section *section)
+{
+	return add_memory_block(0, section, MEM_OFFLINE, 0);
+}
+
+int unregister_memory_section(struct mem_section *section)
+{
+	if (!present_section(section))
+		return -EINVAL;
+
+	return remove_memory_block(0, section, 0);
+}
+
+/*
+ * Initialize the sysfs support for memory devices...
+ */
+int __init memory_dev_init(void)
+{
+	unsigned int i;
+	int ret;
+	int err;
+
+	memory_sysdev_class.kset.uevent_ops = &memory_uevent_ops;
+	ret = sysdev_class_register(&memory_sysdev_class);
+	if (ret)
+		goto out;
+
+	/*
+	 * Create entries for memory sections that were found
+	 * during boot and have been initialized
+	 */
+	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, 0);
+		if (!ret)
+			ret = err;
+	}
+
+	err = memory_probe_init();
+	if (!ret)
+		ret = err;
+	err = block_size_init();
+	if (!ret)
+		ret = err;
+out:
+	if (ret)
+		printk(KERN_ERR "%s() failed: %d\n", __func__, ret);
+	return ret;
+}