/* * drivers/s390/char/monreader.c * * Character device driver for reading z/VM *MONITOR service records. * * Copyright 2004 IBM Corporation, IBM Deutschland Entwicklung GmbH. * * Author: Gerald Schaefer <geraldsc@de.ibm.com> */ #include <linux/module.h> #include <linux/moduleparam.h> #include <linux/init.h> #include <linux/errno.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/miscdevice.h> #include <linux/ctype.h> #include <linux/spinlock.h> #include <linux/interrupt.h> #include <asm/uaccess.h> #include <asm/ebcdic.h> #include <asm/extmem.h> #include <linux/poll.h> #include <net/iucv/iucv.h> //#define MON_DEBUG /* Debug messages on/off */ #define MON_NAME "monreader" #define P_INFO(x...) printk(KERN_INFO MON_NAME " info: " x) #define P_ERROR(x...) printk(KERN_ERR MON_NAME " error: " x) #define P_WARNING(x...) printk(KERN_WARNING MON_NAME " warning: " x) #ifdef MON_DEBUG #define P_DEBUG(x...) printk(KERN_DEBUG MON_NAME " debug: " x) #else #define P_DEBUG(x...) do {} while (0) #endif #define MON_COLLECT_SAMPLE 0x80 #define MON_COLLECT_EVENT 0x40 #define MON_SERVICE "*MONITOR" #define MON_IN_USE 0x01 #define MON_MSGLIM 255 static char mon_dcss_name[9] = "MONDCSS\0"; struct mon_msg { u32 pos; u32 mca_offset; struct iucv_message msg; char msglim_reached; char replied_msglim; }; struct mon_private { struct iucv_path *path; struct mon_msg *msg_array[MON_MSGLIM]; unsigned int write_index; unsigned int read_index; atomic_t msglim_count; atomic_t read_ready; atomic_t iucv_connected; atomic_t iucv_severed; }; static unsigned long mon_in_use = 0; static unsigned long mon_dcss_start; static unsigned long mon_dcss_end; static DECLARE_WAIT_QUEUE_HEAD(mon_read_wait_queue); static DECLARE_WAIT_QUEUE_HEAD(mon_conn_wait_queue); static u8 user_data_connect[16] = { /* Version code, must be 0x01 for shared mode */ 0x01, /* what to collect */ MON_COLLECT_SAMPLE | MON_COLLECT_EVENT, /* DCSS name in EBCDIC, 8 bytes padded with blanks */ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, }; static u8 user_data_sever[16] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, }; /****************************************************************************** * helper functions * *****************************************************************************/ /* * Create the 8 bytes EBCDIC DCSS segment name from * an ASCII name, incl. padding */ static void dcss_mkname(char *ascii_name, char *ebcdic_name) { int i; for (i = 0; i < 8; i++) { if (ascii_name[i] == '\0') break; ebcdic_name[i] = toupper(ascii_name[i]); }; for (; i < 8; i++) ebcdic_name[i] = ' '; ASCEBC(ebcdic_name, 8); } static inline unsigned long mon_mca_start(struct mon_msg *monmsg) { return *(u32 *) &monmsg->msg.rmmsg; } static inline unsigned long mon_mca_end(struct mon_msg *monmsg) { return *(u32 *) &monmsg->msg.rmmsg[4]; } static inline u8 mon_mca_type(struct mon_msg *monmsg, u8 index) { return *((u8 *) mon_mca_start(monmsg) + monmsg->mca_offset + index); } static inline u32 mon_mca_size(struct mon_msg *monmsg) { return mon_mca_end(monmsg) - mon_mca_start(monmsg) + 1; } static inline u32 mon_rec_start(struct mon_msg *monmsg) { return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 4)); } static inline u32 mon_rec_end(struct mon_msg *monmsg) { return *((u32 *) (mon_mca_start(monmsg) + monmsg->mca_offset + 8)); } static int mon_check_mca(struct mon_msg *monmsg) { if ((mon_rec_end(monmsg) <= mon_rec_start(monmsg)) || (mon_rec_start(monmsg) < mon_dcss_start) || (mon_rec_end(monmsg) > mon_dcss_end) || (mon_mca_type(monmsg, 0) == 0) || (mon_mca_size(monmsg) % 12 != 0) || (mon_mca_end(monmsg) <= mon_mca_start(monmsg)) || (mon_mca_end(monmsg) > mon_dcss_end) || (mon_mca_start(monmsg) < mon_dcss_start) || ((mon_mca_type(monmsg, 1) == 0) && (mon_mca_type(monmsg, 2) == 0))) { P_DEBUG("READ, IGNORED INVALID MCA\n\n"); return -EINVAL; } return 0; } static int mon_send_reply(struct mon_msg *monmsg, struct mon_private *monpriv) { int rc; P_DEBUG("read, REPLY: pathid = 0x%04X, msgid = 0x%08X, trgcls = " "0x%08X\n\n", monpriv->path->pathid, monmsg->msg.id, monmsg->msg.class); rc = iucv_message_reply(monpriv->path, &monmsg->msg, IUCV_IPRMDATA, NULL, 0); atomic_dec(&monpriv->msglim_count); if (likely(!monmsg->msglim_reached)) { monmsg->pos = 0; monmsg->mca_offset = 0; monpriv->read_index = (monpriv->read_index + 1) % MON_MSGLIM; atomic_dec(&monpriv->read_ready); } else monmsg->replied_msglim = 1; if (rc) { P_ERROR("read, IUCV reply failed with rc = %i\n\n", rc); return -EIO; } return 0; } static void mon_free_mem(struct mon_private *monpriv) { int i; for (i = 0; i < MON_MSGLIM; i++) if (monpriv->msg_array[i]) kfree(monpriv->msg_array[i]); kfree(monpriv); } static struct mon_private *mon_alloc_mem(void) { int i; struct mon_private *monpriv; monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL); if (!monpriv) { P_ERROR("no memory for monpriv\n"); return NULL; } for (i = 0; i < MON_MSGLIM; i++) { monpriv->msg_array[i] = kzalloc(sizeof(struct mon_msg), GFP_KERNEL); if (!monpriv->msg_array[i]) { P_ERROR("open, no memory for msg_array\n"); mon_free_mem(monpriv); return NULL; } } return monpriv; } static inline void mon_read_debug(struct mon_msg *monmsg, struct mon_private *monpriv) { #ifdef MON_DEBUG u8 msg_type[2], mca_type; unsigned long records_len; records_len = mon_rec_end(monmsg) - mon_rec_start(monmsg) + 1; memcpy(msg_type, &monmsg->msg.class, 2); EBCASC(msg_type, 2); mca_type = mon_mca_type(monmsg, 0); EBCASC(&mca_type, 1); P_DEBUG("read, mon_read_index = %i, mon_write_index = %i\n", monpriv->read_index, monpriv->write_index); P_DEBUG("read, pathid = 0x%04X, msgid = 0x%08X, trgcls = 0x%08X\n", monpriv->path->pathid, monmsg->msg.id, monmsg->msg.class); P_DEBUG("read, msg_type = '%c%c', mca_type = '%c' / 0x%X / 0x%X\n", msg_type[0], msg_type[1], mca_type ? mca_type : 'X', mon_mca_type(monmsg, 1), mon_mca_type(monmsg, 2)); P_DEBUG("read, MCA: start = 0x%lX, end = 0x%lX\n", mon_mca_start(monmsg), mon_mca_end(monmsg)); P_DEBUG("read, REC: start = 0x%X, end = 0x%X, len = %lu\n\n", mon_rec_start(monmsg), mon_rec_end(monmsg), records_len); if (mon_mca_size(monmsg) > 12) P_DEBUG("READ, MORE THAN ONE MCA\n\n"); #endif } static inline void mon_next_mca(struct mon_msg *monmsg) { if (likely((mon_mca_size(monmsg) - monmsg->mca_offset) == 12)) return; P_DEBUG("READ, NEXT MCA\n\n"); monmsg->mca_offset += 12; monmsg->pos = 0; } static struct mon_msg *mon_next_message(struct mon_private *monpriv) { struct mon_msg *monmsg; if (!atomic_read(&monpriv->read_ready)) return NULL; monmsg = monpriv->msg_array[monpriv->read_index]; if (unlikely(monmsg->replied_msglim)) { monmsg->replied_msglim = 0; monmsg->msglim_reached = 0; monmsg->pos = 0; monmsg->mca_offset = 0; P_WARNING("read, message limit reached\n"); monpriv->read_index = (monpriv->read_index + 1) % MON_MSGLIM; atomic_dec(&monpriv->read_ready); return ERR_PTR(-EOVERFLOW); } return monmsg; } /****************************************************************************** * IUCV handler * *****************************************************************************/ static void mon_iucv_path_complete(struct iucv_path *path, u8 ipuser[16]) { struct mon_private *monpriv = path->private; P_DEBUG("IUCV connection completed\n"); P_DEBUG("IUCV ACCEPT (from *MONITOR): Version = 0x%02X, Event = " "0x%02X, Sample = 0x%02X\n", ipuser[0], ipuser[1], ipuser[2]); atomic_set(&monpriv->iucv_connected, 1); wake_up(&mon_conn_wait_queue); } static void mon_iucv_path_severed(struct iucv_path *path, u8 ipuser[16]) { struct mon_private *monpriv = path->private; P_ERROR("IUCV connection severed with rc = 0x%X\n", ipuser[0]); iucv_path_sever(path, NULL); atomic_set(&monpriv->iucv_severed, 1); wake_up(&mon_conn_wait_queue); wake_up_interruptible(&mon_read_wait_queue); } static void mon_iucv_message_pending(struct iucv_path *path, struct iucv_message *msg) { struct mon_private *monpriv = path->private; P_DEBUG("IUCV message pending\n"); memcpy(&monpriv->msg_array[monpriv->write_index]->msg, msg, sizeof(*msg)); if (atomic_inc_return(&monpriv->msglim_count) == MON_MSGLIM) { P_WARNING("IUCV message pending, message limit (%i) reached\n", MON_MSGLIM); monpriv->msg_array[monpriv->write_index]->msglim_reached = 1; } monpriv->write_index = (monpriv->write_index + 1) % MON_MSGLIM; atomic_inc(&monpriv->read_ready); wake_up_interruptible(&mon_read_wait_queue); } static struct iucv_handler monreader_iucv_handler = { .path_complete = mon_iucv_path_complete, .path_severed = mon_iucv_path_severed, .message_pending = mon_iucv_message_pending, }; /****************************************************************************** * file operations * *****************************************************************************/ static int mon_open(struct inode *inode, struct file *filp) { struct mon_private *monpriv; int rc; /* * only one user allowed */ rc = -EBUSY; if (test_and_set_bit(MON_IN_USE, &mon_in_use)) goto out; rc = -ENOMEM; monpriv = mon_alloc_mem(); if (!monpriv) goto out_use; /* * Connect to *MONITOR service */ monpriv->path = iucv_path_alloc(MON_MSGLIM, IUCV_IPRMDATA, GFP_KERNEL); if (!monpriv->path) goto out_priv; rc = iucv_path_connect(monpriv->path, &monreader_iucv_handler, MON_SERVICE, NULL, user_data_connect, monpriv); if (rc) { P_ERROR("iucv connection to *MONITOR failed with " "IPUSER SEVER code = %i\n", rc); rc = -EIO; goto out_path; } /* * Wait for connection confirmation */ wait_event(mon_conn_wait_queue, atomic_read(&monpriv->iucv_connected) || atomic_read(&monpriv->iucv_severed)); if (atomic_read(&monpriv->iucv_severed)) { atomic_set(&monpriv->iucv_severed, 0); atomic_set(&monpriv->iucv_connected, 0); rc = -EIO; goto out_path; } P_INFO("open, established connection to *MONITOR service\n\n"); filp->private_data = monpriv; return nonseekable_open(inode, filp); out_path: kfree(monpriv->path); out_priv: mon_free_mem(monpriv); out_use: clear_bit(MON_IN_USE, &mon_in_use); out: return rc; } static int mon_close(struct inode *inode, struct file *filp) { int rc, i; struct mon_private *monpriv = filp->private_data; /* * Close IUCV connection and unregister */ rc = iucv_path_sever(monpriv->path, user_data_sever); if (rc) P_ERROR("close, iucv_sever failed with rc = %i\n", rc); else P_INFO("close, terminated connection to *MONITOR service\n"); atomic_set(&monpriv->iucv_severed, 0); atomic_set(&monpriv->iucv_connected, 0); atomic_set(&monpriv->read_ready, 0); atomic_set(&monpriv->msglim_count, 0); monpriv->write_index = 0; monpriv->read_index = 0; for (i = 0; i < MON_MSGLIM; i++) kfree(monpriv->msg_array[i]); kfree(monpriv); clear_bit(MON_IN_USE, &mon_in_use); return 0; } static ssize_t mon_read(struct file *filp, char __user *data, size_t count, loff_t *ppos) { struct mon_private *monpriv = filp->private_data; struct mon_msg *monmsg; int ret; u32 mce_start; monmsg = mon_next_message(monpriv); if (IS_ERR(monmsg)) return PTR_ERR(monmsg); if (!monmsg) { if (filp->f_flags & O_NONBLOCK) return -EAGAIN; ret = wait_event_interruptible(mon_read_wait_queue, atomic_read(&monpriv->read_ready) || atomic_read(&monpriv->iucv_severed)); if (ret) return ret; if (unlikely(atomic_read(&monpriv->iucv_severed))) return -EIO; monmsg = monpriv->msg_array[monpriv->read_index]; } if (!monmsg->pos) { monmsg->pos = mon_mca_start(monmsg) + monmsg->mca_offset; mon_read_debug(monmsg, monpriv); } if (mon_check_mca(monmsg)) goto reply; /* read monitor control element (12 bytes) first */ mce_start = mon_mca_start(monmsg) + monmsg->mca_offset; if ((monmsg->pos >= mce_start) && (monmsg->pos < mce_start + 12)) { count = min(count, (size_t) mce_start + 12 - monmsg->pos); ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos, count); if (ret) return -EFAULT; monmsg->pos += count; if (monmsg->pos == mce_start + 12) monmsg->pos = mon_rec_start(monmsg); goto out_copy; } /* read records */ if (monmsg->pos <= mon_rec_end(monmsg)) { count = min(count, (size_t) mon_rec_end(monmsg) - monmsg->pos + 1); ret = copy_to_user(data, (void *) (unsigned long) monmsg->pos, count); if (ret) return -EFAULT; monmsg->pos += count; if (monmsg->pos > mon_rec_end(monmsg)) mon_next_mca(monmsg); goto out_copy; } reply: ret = mon_send_reply(monmsg, monpriv); return ret; out_copy: *ppos += count; return count; } static unsigned int mon_poll(struct file *filp, struct poll_table_struct *p) { struct mon_private *monpriv = filp->private_data; poll_wait(filp, &mon_read_wait_queue, p); if (unlikely(atomic_read(&monpriv->iucv_severed))) return POLLERR; if (atomic_read(&monpriv->read_ready)) return POLLIN | POLLRDNORM; return 0; } static const struct file_operations mon_fops = { .owner = THIS_MODULE, .open = &mon_open, .release = &mon_close, .read = &mon_read, .poll = &mon_poll, }; static struct miscdevice mon_dev = { .name = "monreader", .fops = &mon_fops, .minor = MISC_DYNAMIC_MINOR, }; /****************************************************************************** * module init/exit * *****************************************************************************/ static int __init mon_init(void) { int rc; if (!MACHINE_IS_VM) { P_ERROR("not running under z/VM, driver not loaded\n"); return -ENODEV; } /* * Register with IUCV and connect to *MONITOR service */ rc = iucv_register(&monreader_iucv_handler, 1); if (rc) { P_ERROR("failed to register with iucv driver\n"); return rc; } P_INFO("open, registered with IUCV\n"); rc = segment_type(mon_dcss_name); if (rc < 0) { segment_warning(rc, mon_dcss_name); goto out_iucv; } if (rc != SEG_TYPE_SC) { P_ERROR("segment %s has unsupported type, should be SC\n", mon_dcss_name); rc = -EINVAL; goto out_iucv; } rc = segment_load(mon_dcss_name, SEGMENT_SHARED, &mon_dcss_start, &mon_dcss_end); if (rc < 0) { segment_warning(rc, mon_dcss_name); rc = -EINVAL; goto out_iucv; } dcss_mkname(mon_dcss_name, &user_data_connect[8]); rc = misc_register(&mon_dev); if (rc < 0 ) { P_ERROR("misc_register failed, rc = %i\n", rc); goto out; } P_INFO("Loaded segment %s from %p to %p, size = %lu Byte\n", mon_dcss_name, (void *) mon_dcss_start, (void *) mon_dcss_end, mon_dcss_end - mon_dcss_start + 1); return 0; out: segment_unload(mon_dcss_name); out_iucv: iucv_unregister(&monreader_iucv_handler, 1); return rc; } static void __exit mon_exit(void) { segment_unload(mon_dcss_name); WARN_ON(misc_deregister(&mon_dev) != 0); iucv_unregister(&monreader_iucv_handler, 1); return; } module_init(mon_init); module_exit(mon_exit); module_param_string(mondcss, mon_dcss_name, 9, 0444); MODULE_PARM_DESC(mondcss, "Name of DCSS segment to be used for *MONITOR " "service, max. 8 chars. Default is MONDCSS"); MODULE_AUTHOR("Gerald Schaefer <geraldsc@de.ibm.com>"); MODULE_DESCRIPTION("Character device driver for reading z/VM " "monitor service records."); MODULE_LICENSE("GPL");