--- /dev/null
+/*
+ * Collaborative memory management interface.
+ *
+ * Copyright (C) 2008 IBM Corporation
+ * Author(s): Brian King (brking@linux.vnet.ibm.com),
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/oom.h>
+#include <linux/sched.h>
+#include <linux/stringify.h>
+#include <linux/swap.h>
+#include <linux/sysdev.h>
+#include <asm/firmware.h>
+#include <asm/hvcall.h>
+#include <asm/mmu.h>
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+
+#include "plpar_wrappers.h"
+
+#define CMM_DRIVER_VERSION "1.0.0"
+#define CMM_DEFAULT_DELAY 1
+#define CMM_DEBUG 0
+#define CMM_DISABLE 0
+#define CMM_OOM_KB 1024
+#define CMM_MIN_MEM_MB 256
+#define KB2PAGES(_p) ((_p)>>(PAGE_SHIFT-10))
+#define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10))
+
+static unsigned int delay = CMM_DEFAULT_DELAY;
+static unsigned int oom_kb = CMM_OOM_KB;
+static unsigned int cmm_debug = CMM_DEBUG;
+static unsigned int cmm_disabled = CMM_DISABLE;
+static unsigned long min_mem_mb = CMM_MIN_MEM_MB;
+static struct sys_device cmm_sysdev;
+
+MODULE_AUTHOR("Brian King <brking@linux.vnet.ibm.com>");
+MODULE_DESCRIPTION("IBM System p Collaborative Memory Manager");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(CMM_DRIVER_VERSION);
+
+module_param_named(delay, delay, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(delay, "Delay (in seconds) between polls to query hypervisor paging requests. "
+ "[Default=" __stringify(CMM_DEFAULT_DELAY) "]");
+module_param_named(oom_kb, oom_kb, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(oom_kb, "Amount of memory in kb to free on OOM. "
+ "[Default=" __stringify(CMM_OOM_KB) "]");
+module_param_named(min_mem_mb, min_mem_mb, ulong, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(min_mem_mb, "Minimum amount of memory (in MB) to not balloon. "
+ "[Default=" __stringify(CMM_MIN_MEM_MB) "]");
+module_param_named(debug, cmm_debug, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug, "Enable module debugging logging. Set to 1 to enable. "
+ "[Default=" __stringify(CMM_DEBUG) "]");
+
+#define CMM_NR_PAGES ((PAGE_SIZE - sizeof(void *) - sizeof(unsigned long)) / sizeof(unsigned long))
+
+#define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__); }
+
+struct cmm_page_array {
+ struct cmm_page_array *next;
+ unsigned long index;
+ unsigned long page[CMM_NR_PAGES];
+};
+
+static unsigned long loaned_pages;
+static unsigned long loaned_pages_target;
+static unsigned long oom_freed_pages;
+
+static struct cmm_page_array *cmm_page_list;
+static DEFINE_SPINLOCK(cmm_lock);
+
+static struct task_struct *cmm_thread_ptr;
+
+/**
+ * cmm_alloc_pages - Allocate pages and mark them as loaned
+ * @nr: number of pages to allocate
+ *
+ * Return value:
+ * number of pages requested to be allocated which were not
+ **/
+static long cmm_alloc_pages(long nr)
+{
+ struct cmm_page_array *pa, *npa;
+ unsigned long addr;
+ long rc;
+
+ cmm_dbg("Begin request for %ld pages\n", nr);
+
+ while (nr) {
+ addr = __get_free_page(GFP_NOIO | __GFP_NOWARN |
+ __GFP_NORETRY | __GFP_NOMEMALLOC);
+ if (!addr)
+ break;
+ spin_lock(&cmm_lock);
+ pa = cmm_page_list;
+ if (!pa || pa->index >= CMM_NR_PAGES) {
+ /* Need a new page for the page list. */
+ spin_unlock(&cmm_lock);
+ npa = (struct cmm_page_array *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
+ __GFP_NORETRY | __GFP_NOMEMALLOC);
+ if (!npa) {
+ pr_info("%s: Can not allocate new page list\n", __FUNCTION__);
+ free_page(addr);
+ break;
+ }
+ spin_lock(&cmm_lock);
+ pa = cmm_page_list;
+
+ if (!pa || pa->index >= CMM_NR_PAGES) {
+ npa->next = pa;
+ npa->index = 0;
+ pa = npa;
+ cmm_page_list = pa;
+ } else
+ free_page((unsigned long) npa);
+ }
+
+ if ((rc = plpar_page_set_loaned(__pa(addr)))) {
+ pr_err("%s: Can not set page to loaned. rc=%ld\n", __FUNCTION__, rc);
+ spin_unlock(&cmm_lock);
+ free_page(addr);
+ break;
+ }
+
+ pa->page[pa->index++] = addr;
+ loaned_pages++;
+ totalram_pages--;
+ spin_unlock(&cmm_lock);
+ nr--;
+ }
+
+ cmm_dbg("End request with %ld pages unfulfilled\n", nr);
+ return nr;
+}
+
+/**
+ * cmm_free_pages - Free pages and mark them as active
+ * @nr: number of pages to free
+ *
+ * Return value:
+ * number of pages requested to be freed which were not
+ **/
+static long cmm_free_pages(long nr)
+{
+ struct cmm_page_array *pa;
+ unsigned long addr;
+
+ cmm_dbg("Begin free of %ld pages.\n", nr);
+ spin_lock(&cmm_lock);
+ pa = cmm_page_list;
+ while (nr) {
+ if (!pa || pa->index <= 0)
+ break;
+ addr = pa->page[--pa->index];
+
+ if (pa->index == 0) {
+ pa = pa->next;
+ free_page((unsigned long) cmm_page_list);
+ cmm_page_list = pa;
+ }
+
+ plpar_page_set_active(__pa(addr));
+ free_page(addr);
+ loaned_pages--;
+ nr--;
+ totalram_pages++;
+ }
+ spin_unlock(&cmm_lock);
+ cmm_dbg("End request with %ld pages unfulfilled\n", nr);
+ return nr;
+}
+
+/**
+ * cmm_oom_notify - OOM notifier
+ * @self: notifier block struct
+ * @dummy: not used
+ * @parm: returned - number of pages freed
+ *
+ * Return value:
+ * NOTIFY_OK
+ **/
+static int cmm_oom_notify(struct notifier_block *self,
+ unsigned long dummy, void *parm)
+{
+ unsigned long *freed = parm;
+ long nr = KB2PAGES(oom_kb);
+
+ cmm_dbg("OOM processing started\n");
+ nr = cmm_free_pages(nr);
+ loaned_pages_target = loaned_pages;
+ *freed += KB2PAGES(oom_kb) - nr;
+ oom_freed_pages += KB2PAGES(oom_kb) - nr;
+ cmm_dbg("OOM processing complete\n");
+ return NOTIFY_OK;
+}
+
+/**
+ * cmm_get_mpp - Read memory performance parameters
+ *
+ * Makes hcall to query the current page loan request from the hypervisor.
+ *
+ * Return value:
+ * nothing
+ **/
+static void cmm_get_mpp(void)
+{
+ int rc;
+ struct hvcall_mpp_data mpp_data;
+ unsigned long active_pages_target;
+ signed long page_loan_request;
+
+ rc = h_get_mpp(&mpp_data);
+
+ if (rc != H_SUCCESS)
+ return;
+
+ page_loan_request = div_s64((s64)mpp_data.loan_request, PAGE_SIZE);
+ loaned_pages_target = page_loan_request + loaned_pages;
+ if (loaned_pages_target > oom_freed_pages)
+ loaned_pages_target -= oom_freed_pages;
+ else
+ loaned_pages_target = 0;
+
+ active_pages_target = totalram_pages + loaned_pages - loaned_pages_target;
+
+ if ((min_mem_mb * 1024 * 1024) > (active_pages_target * PAGE_SIZE))
+ loaned_pages_target = totalram_pages + loaned_pages -
+ ((min_mem_mb * 1024 * 1024) / PAGE_SIZE);
+
+ cmm_dbg("delta = %ld, loaned = %lu, target = %lu, oom = %lu, totalram = %lu\n",
+ page_loan_request, loaned_pages, loaned_pages_target,
+ oom_freed_pages, totalram_pages);
+}
+
+static struct notifier_block cmm_oom_nb = {
+ .notifier_call = cmm_oom_notify
+};
+
+/**
+ * cmm_thread - CMM task thread
+ * @dummy: not used
+ *
+ * Return value:
+ * 0
+ **/
+static int cmm_thread(void *dummy)
+{
+ unsigned long timeleft;
+
+ while (1) {
+ timeleft = msleep_interruptible(delay * 1000);
+
+ if (kthread_should_stop() || timeleft) {
+ loaned_pages_target = loaned_pages;
+ break;
+ }
+
+ cmm_get_mpp();
+
+ if (loaned_pages_target > loaned_pages) {
+ if (cmm_alloc_pages(loaned_pages_target - loaned_pages))
+ loaned_pages_target = loaned_pages;
+ } else if (loaned_pages_target < loaned_pages)
+ cmm_free_pages(loaned_pages - loaned_pages_target);
+ }
+ return 0;
+}
+
+#define CMM_SHOW(name, format, args...) \
+ static ssize_t show_##name(struct sys_device *dev, char *buf) \
+ { \
+ return sprintf(buf, format, ##args); \
+ } \
+ static SYSDEV_ATTR(name, S_IRUGO, show_##name, NULL)
+
+CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(loaned_pages));
+CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target));
+
+static ssize_t show_oom_pages(struct sys_device *dev, char *buf)
+{
+ return sprintf(buf, "%lu\n", PAGES2KB(oom_freed_pages));
+}
+
+static ssize_t store_oom_pages(struct sys_device *dev,
+ const char *buf, size_t count)
+{
+ unsigned long val = simple_strtoul (buf, NULL, 10);
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+ if (val != 0)
+ return -EBADMSG;
+
+ oom_freed_pages = 0;
+ return count;
+}
+
+static SYSDEV_ATTR(oom_freed_kb, S_IWUSR| S_IRUGO,
+ show_oom_pages, store_oom_pages);
+
+static struct sysdev_attribute *cmm_attrs[] = {
+ &attr_loaned_kb,
+ &attr_loaned_target_kb,
+ &attr_oom_freed_kb,
+};
+
+static struct sysdev_class cmm_sysdev_class = {
+ .name = "cmm",
+};
+
+/**
+ * cmm_sysfs_register - Register with sysfs
+ *
+ * Return value:
+ * 0 on success / other on failure
+ **/
+static int cmm_sysfs_register(struct sys_device *sysdev)
+{
+ int i, rc;
+
+ if ((rc = sysdev_class_register(&cmm_sysdev_class)))
+ return rc;
+
+ sysdev->id = 0;
+ sysdev->cls = &cmm_sysdev_class;
+
+ if ((rc = sysdev_register(sysdev)))
+ goto class_unregister;
+
+ for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) {
+ if ((rc = sysdev_create_file(sysdev, cmm_attrs[i])))
+ goto fail;
+ }
+
+ return 0;
+
+fail:
+ while (--i >= 0)
+ sysdev_remove_file(sysdev, cmm_attrs[i]);
+ sysdev_unregister(sysdev);
+class_unregister:
+ sysdev_class_unregister(&cmm_sysdev_class);
+ return rc;
+}
+
+/**
+ * cmm_unregister_sysfs - Unregister from sysfs
+ *
+ **/
+static void cmm_unregister_sysfs(struct sys_device *sysdev)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++)
+ sysdev_remove_file(sysdev, cmm_attrs[i]);
+ sysdev_unregister(sysdev);
+ sysdev_class_unregister(&cmm_sysdev_class);
+}
+
+/**
+ * cmm_init - Module initialization
+ *
+ * Return value:
+ * 0 on success / other on failure
+ **/
+static int cmm_init(void)
+{
+ int rc = -ENOMEM;
+
+ if (!firmware_has_feature(FW_FEATURE_CMO))
+ return -EOPNOTSUPP;
+
+ if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0)
+ return rc;
+
+ if ((rc = cmm_sysfs_register(&cmm_sysdev)))
+ goto out_oom_notifier;
+
+ if (cmm_disabled)
+ return rc;
+
+ cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
+ if (IS_ERR(cmm_thread_ptr)) {
+ rc = PTR_ERR(cmm_thread_ptr);
+ goto out_unregister_sysfs;
+ }
+
+ return rc;
+
+out_unregister_sysfs:
+ cmm_unregister_sysfs(&cmm_sysdev);
+out_oom_notifier:
+ unregister_oom_notifier(&cmm_oom_nb);
+ return rc;
+}
+
+/**
+ * cmm_exit - Module exit
+ *
+ * Return value:
+ * nothing
+ **/
+static void cmm_exit(void)
+{
+ if (cmm_thread_ptr)
+ kthread_stop(cmm_thread_ptr);
+ unregister_oom_notifier(&cmm_oom_nb);
+ cmm_free_pages(loaned_pages);
+ cmm_unregister_sysfs(&cmm_sysdev);
+}
+
+/**
+ * cmm_set_disable - Disable/Enable CMM
+ *
+ * Return value:
+ * 0 on success / other on failure
+ **/
+static int cmm_set_disable(const char *val, struct kernel_param *kp)
+{
+ int disable = simple_strtoul(val, NULL, 10);
+
+ if (disable != 0 && disable != 1)
+ return -EINVAL;
+
+ if (disable && !cmm_disabled) {
+ if (cmm_thread_ptr)
+ kthread_stop(cmm_thread_ptr);
+ cmm_thread_ptr = NULL;
+ cmm_free_pages(loaned_pages);
+ } else if (!disable && cmm_disabled) {
+ cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
+ if (IS_ERR(cmm_thread_ptr))
+ return PTR_ERR(cmm_thread_ptr);
+ }
+
+ cmm_disabled = disable;
+ return 0;
+}
+
+module_param_call(disable, cmm_set_disable, param_get_uint,
+ &cmm_disabled, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(disable, "Disable CMM. Set to 1 to disable. "
+ "[Default=" __stringify(CMM_DISABLE) "]");
+
+module_init(cmm_init);
+module_exit(cmm_exit);
projects / linux-2.6-omap-h63xx.git / commitdiff