/* * 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 <asm/smp.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"); set_cpus_allowed(current, cpumask_of_cpu(0)); 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) { int rc; /* Prevent logical cpu 0 from being set offline. */ rc = smp_get_cpu(cpumask_of_cpu(0)); if (rc) { printk(KERN_ERR "CMM: unable to reserve cpu 0\n"); return rc; } #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 /* Allow logical cpu 0 to be set offline again. */ smp_put_cpu(0); } 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");