1 files changed, 443 insertions, 0 deletions

diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
new file mode 100644
index 000000000000..d30cdb4248a9
--- /dev/null
+++ b/arch/s390/mm/cmm.c
@@ -0,0 +1,443 @@
+/*
+ *  arch/s390/mm/cmm.c
+ *
+ *  S390 version
+ *    Copyright (C) 2003 IBM Deutschland Entwicklung GmbH, IBM Corporation
+ *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
+ *
+ *  Collaborative memory management interface.
+ */
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sysctl.h>
+#include <linux/ctype.h>
+
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+
+#include "../../../drivers/s390/net/smsgiucv.h"
+
+#define CMM_NR_PAGES ((PAGE_SIZE / sizeof(unsigned long)) - 2)
+
+struct cmm_page_array {
+	struct cmm_page_array *next;
+	unsigned long index;
+	unsigned long pages[CMM_NR_PAGES];
+};
+
+static long cmm_pages = 0;
+static long cmm_timed_pages = 0;
+static volatile long cmm_pages_target = 0;
+static volatile long cmm_timed_pages_target = 0;
+static long cmm_timeout_pages = 0;
+static long cmm_timeout_seconds = 0;
+
+static struct cmm_page_array *cmm_page_list = 0;
+static struct cmm_page_array *cmm_timed_page_list = 0;
+
+static unsigned long cmm_thread_active = 0;
+static struct work_struct cmm_thread_starter;
+static wait_queue_head_t cmm_thread_wait;
+static struct timer_list cmm_timer;
+
+static void cmm_timer_fn(unsigned long);
+static void cmm_set_timer(void);
+
+static long
+cmm_strtoul(const char *cp, char **endp)
+{
+	unsigned int base = 10;
+
+	if (*cp == '0') {
+		base = 8;
+		cp++;
+		if ((*cp == 'x' || *cp == 'X') && isxdigit(cp[1])) {
+			base = 16;
+			cp++;
+		}
+	}
+	return simple_strtoul(cp, endp, base);
+}
+
+static long
+cmm_alloc_pages(long pages, long *counter, struct cmm_page_array **list)
+{
+	struct cmm_page_array *pa;
+	unsigned long page;
+
+	pa = *list;
+	while (pages) {
+		page = __get_free_page(GFP_NOIO);
+		if (!page)
+			break;
+		if (!pa || pa->index >= CMM_NR_PAGES) {
+			/* Need a new page for the page list. */
+			pa = (struct cmm_page_array *)
+				__get_free_page(GFP_NOIO);
+			if (!pa) {
+				free_page(page);
+				break;
+			}
+			pa->next = *list;
+			pa->index = 0;
+			*list = pa;
+		}
+		diag10(page);
+		pa->pages[pa->index++] = page;
+		(*counter)++;
+		pages--;
+	}
+	return pages;
+}
+
+static void
+cmm_free_pages(long pages, long *counter, struct cmm_page_array **list)
+{
+	struct cmm_page_array *pa;
+	unsigned long page;
+
+	pa = *list;
+	while (pages) {
+		if (!pa || pa->index <= 0)
+			break;
+		page = pa->pages[--pa->index];
+		if (pa->index == 0) {
+			pa = pa->next;
+			free_page((unsigned long) *list);
+			*list = pa;
+		}
+		free_page(page);
+		(*counter)--;
+		pages--;
+	}
+}
+
+static int
+cmm_thread(void *dummy)
+{
+	int rc;
+
+	daemonize("cmmthread");
+	while (1) {
+		rc = wait_event_interruptible(cmm_thread_wait,
+			(cmm_pages != cmm_pages_target ||
+			 cmm_timed_pages != cmm_timed_pages_target));
+		if (rc == -ERESTARTSYS) {
+			/* Got kill signal. End thread. */
+			clear_bit(0, &cmm_thread_active);
+			cmm_pages_target = cmm_pages;
+			cmm_timed_pages_target = cmm_timed_pages;
+			break;
+		}
+		if (cmm_pages_target > cmm_pages) {
+			if (cmm_alloc_pages(1, &cmm_pages, &cmm_page_list))
+				cmm_pages_target = cmm_pages;
+		} else if (cmm_pages_target < cmm_pages) {
+			cmm_free_pages(1, &cmm_pages, &cmm_page_list);
+		}
+		if (cmm_timed_pages_target > cmm_timed_pages) {
+			if (cmm_alloc_pages(1, &cmm_timed_pages,
+					   &cmm_timed_page_list))
+				cmm_timed_pages_target = cmm_timed_pages;
+		} else if (cmm_timed_pages_target < cmm_timed_pages) {
+			cmm_free_pages(1, &cmm_timed_pages,
+			       	       &cmm_timed_page_list);
+		}
+		if (cmm_timed_pages > 0 && !timer_pending(&cmm_timer))
+			cmm_set_timer();
+	}
+	return 0;
+}
+
+static void
+cmm_start_thread(void)
+{
+	kernel_thread(cmm_thread, 0, 0);
+}
+
+static void
+cmm_kick_thread(void)
+{
+	if (!test_and_set_bit(0, &cmm_thread_active))
+		schedule_work(&cmm_thread_starter);
+	wake_up(&cmm_thread_wait);
+}
+
+static void
+cmm_set_timer(void)
+{
+	if (cmm_timed_pages_target <= 0 || cmm_timeout_seconds <= 0) {
+		if (timer_pending(&cmm_timer))
+			del_timer(&cmm_timer);
+		return;
+	}
+	if (timer_pending(&cmm_timer)) {
+		if (mod_timer(&cmm_timer, jiffies + cmm_timeout_seconds*HZ))
+			return;
+	}
+	cmm_timer.function = cmm_timer_fn;
+	cmm_timer.data = 0;
+	cmm_timer.expires = jiffies + cmm_timeout_seconds*HZ;
+	add_timer(&cmm_timer);
+}
+
+static void
+cmm_timer_fn(unsigned long ignored)
+{
+	long pages;
+
+	pages = cmm_timed_pages_target - cmm_timeout_pages;
+	if (pages < 0)
+		cmm_timed_pages_target = 0;
+	else
+		cmm_timed_pages_target = pages;
+	cmm_kick_thread();
+	cmm_set_timer();
+}
+
+void
+cmm_set_pages(long pages)
+{
+	cmm_pages_target = pages;
+	cmm_kick_thread();
+}
+
+long
+cmm_get_pages(void)
+{
+	return cmm_pages;
+}
+
+void
+cmm_add_timed_pages(long pages)
+{
+	cmm_timed_pages_target += pages;
+	cmm_kick_thread();
+}
+
+long
+cmm_get_timed_pages(void)
+{
+	return cmm_timed_pages;
+}
+
+void
+cmm_set_timeout(long pages, long seconds)
+{
+	cmm_timeout_pages = pages;
+	cmm_timeout_seconds = seconds;
+	cmm_set_timer();
+}
+
+static inline int
+cmm_skip_blanks(char *cp, char **endp)
+{
+	char *str;
+
+	for (str = cp; *str == ' ' || *str == '\t'; str++);
+	*endp = str;
+	return str != cp;
+}
+
+#ifdef CONFIG_CMM_PROC
+/* These will someday get removed. */
+#define VM_CMM_PAGES		1111
+#define VM_CMM_TIMED_PAGES	1112
+#define VM_CMM_TIMEOUT		1113
+
+static struct ctl_table cmm_table[];
+
+static int
+cmm_pages_handler(ctl_table *ctl, int write, struct file *filp,
+		  void *buffer, size_t *lenp, loff_t *ppos)
+{
+	char buf[16], *p;
+	long pages;
+	int len;
+
+	if (!*lenp || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	if (write) {
+		len = *lenp;
+		if (copy_from_user(buf, buffer,
+				   len > sizeof(buf) ? sizeof(buf) : len))
+			return -EFAULT;
+		buf[sizeof(buf) - 1] = '\0';
+		cmm_skip_blanks(buf, &p);
+		pages = cmm_strtoul(p, &p);
+		if (ctl == &cmm_table[0])
+			cmm_set_pages(pages);
+		else
+			cmm_add_timed_pages(pages);
+	} else {
+		if (ctl == &cmm_table[0])
+			pages = cmm_get_pages();
+		else
+			pages = cmm_get_timed_pages();
+		len = sprintf(buf, "%ld\n", pages);
+		if (len > *lenp)
+			len = *lenp;
+		if (copy_to_user(buffer, buf, len))
+			return -EFAULT;
+	}
+	*lenp = len;
+	*ppos += len;
+	return 0;
+}
+
+static int
+cmm_timeout_handler(ctl_table *ctl, int write, struct file *filp,
+		    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	char buf[64], *p;
+	long pages, seconds;
+	int len;
+
+	if (!*lenp || (*ppos && !write)) {
+		*lenp = 0;
+		return 0;
+	}
+
+	if (write) {
+		len = *lenp;
+		if (copy_from_user(buf, buffer,
+				   len > sizeof(buf) ? sizeof(buf) : len))
+			return -EFAULT;
+		buf[sizeof(buf) - 1] = '\0';
+		cmm_skip_blanks(buf, &p);
+		pages = cmm_strtoul(p, &p);
+		cmm_skip_blanks(p, &p);
+		seconds = cmm_strtoul(p, &p);
+		cmm_set_timeout(pages, seconds);
+	} else {
+		len = sprintf(buf, "%ld %ld\n",
+			      cmm_timeout_pages, cmm_timeout_seconds);
+		if (len > *lenp)
+			len = *lenp;
+		if (copy_to_user(buffer, buf, len))
+			return -EFAULT;
+	}
+	*lenp = len;
+	*ppos += len;
+	return 0;
+}
+
+static struct ctl_table cmm_table[] = {
+	{
+		.ctl_name	= VM_CMM_PAGES,
+		.procname	= "cmm_pages",
+		.mode		= 0600,
+		.proc_handler	= &cmm_pages_handler,
+	},
+	{
+		.ctl_name	= VM_CMM_TIMED_PAGES,
+		.procname	= "cmm_timed_pages",
+		.mode		= 0600,
+		.proc_handler	= &cmm_pages_handler,
+	},
+	{
+		.ctl_name	= VM_CMM_TIMEOUT,
+		.procname	= "cmm_timeout",
+		.mode		= 0600,
+		.proc_handler	= &cmm_timeout_handler,
+	},
+	{ .ctl_name = 0 }
+};
+
+static struct ctl_table cmm_dir_table[] = {
+	{
+		.ctl_name	= CTL_VM,
+		.procname	= "vm",
+		.maxlen		= 0,
+		.mode		= 0555,
+		.child		= cmm_table,
+	},
+	{ .ctl_name = 0 }
+};
+#endif
+
+#ifdef CONFIG_CMM_IUCV
+#define SMSG_PREFIX "CMM"
+static void
+cmm_smsg_target(char *msg)
+{
+	long pages, seconds;
+
+	if (!cmm_skip_blanks(msg + strlen(SMSG_PREFIX), &msg))
+		return;
+	if (strncmp(msg, "SHRINK", 6) == 0) {
+		if (!cmm_skip_blanks(msg + 6, &msg))
+			return;
+		pages = cmm_strtoul(msg, &msg);
+		cmm_skip_blanks(msg, &msg);
+		if (*msg == '\0')
+			cmm_set_pages(pages);
+	} else if (strncmp(msg, "RELEASE", 7) == 0) {
+		if (!cmm_skip_blanks(msg + 7, &msg))
+			return;
+		pages = cmm_strtoul(msg, &msg);
+		cmm_skip_blanks(msg, &msg);
+		if (*msg == '\0')
+			cmm_add_timed_pages(pages);
+	} else if (strncmp(msg, "REUSE", 5) == 0) {
+		if (!cmm_skip_blanks(msg + 5, &msg))
+			return;
+		pages = cmm_strtoul(msg, &msg);
+		if (!cmm_skip_blanks(msg, &msg))
+			return;
+		seconds = cmm_strtoul(msg, &msg);
+		cmm_skip_blanks(msg, &msg);
+		if (*msg == '\0')
+			cmm_set_timeout(pages, seconds);
+	}
+}
+#endif
+
+struct ctl_table_header *cmm_sysctl_header;
+
+static int
+cmm_init (void)
+{
+#ifdef CONFIG_CMM_PROC
+	cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1);
+#endif
+#ifdef CONFIG_CMM_IUCV
+	smsg_register_callback(SMSG_PREFIX, cmm_smsg_target);
+#endif
+	INIT_WORK(&cmm_thread_starter, (void *) cmm_start_thread, 0);
+	init_waitqueue_head(&cmm_thread_wait);
+	init_timer(&cmm_timer);
+	return 0;
+}
+
+static void
+cmm_exit(void)
+{
+	cmm_free_pages(cmm_pages, &cmm_pages, &cmm_page_list);
+	cmm_free_pages(cmm_timed_pages, &cmm_timed_pages, &cmm_timed_page_list);
+#ifdef CONFIG_CMM_PROC
+	unregister_sysctl_table(cmm_sysctl_header);
+#endif
+#ifdef CONFIG_CMM_IUCV
+	smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
+#endif
+}
+
+module_init(cmm_init);
+module_exit(cmm_exit);
+
+EXPORT_SYMBOL(cmm_set_pages);
+EXPORT_SYMBOL(cmm_get_pages);
+EXPORT_SYMBOL(cmm_add_timed_pages);
+EXPORT_SYMBOL(cmm_get_timed_pages);
+EXPORT_SYMBOL(cmm_set_timeout);
+
+MODULE_LICENSE("GPL");