From: Christian Borntraeger Date: Sat, 25 Jun 2005 21:55:32 +0000 (-0700) Subject: [PATCH] s390: add vmcp interface X-Git-Tag: v2.6.13-rc1~68^2~171 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=6b979de395c7e1b7e59f74a870e1d1911853eccb;p=linux-2.6-omap-h63xx.git [PATCH] s390: add vmcp interface Add interface to issue VM control program commands. Signed-off-by: Martin Schwidefsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/s390/defconfig b/arch/s390/defconfig index 07fd0414a4b..89850b2c27e 100644 --- a/arch/s390/defconfig +++ b/arch/s390/defconfig @@ -245,6 +245,7 @@ CONFIG_S390_TAPE_BLOCK=y # CONFIG_S390_TAPE_34XX=m # CONFIG_VMLOGRDR is not set +# CONFIG_VMCP is not set # CONFIG_MONREADER is not set # CONFIG_DCSS_SHM is not set diff --git a/arch/s390/kernel/cpcmd.c b/arch/s390/kernel/cpcmd.c index 44df8dc07c5..20062145e84 100644 --- a/arch/s390/kernel/cpcmd.c +++ b/arch/s390/kernel/cpcmd.c @@ -2,7 +2,7 @@ * arch/s390/kernel/cpcmd.c * * S390 version - * Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Copyright (C) 1999,2005 IBM Deutschland Entwicklung GmbH, IBM Corporation * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com), * Christian Borntraeger (cborntra@de.ibm.com), */ @@ -18,93 +18,114 @@ #include static DEFINE_SPINLOCK(cpcmd_lock); -static char cpcmd_buf[240]; +static char cpcmd_buf[241]; /* * the caller of __cpcmd has to ensure that the response buffer is below 2 GB */ -void __cpcmd(char *cmd, char *response, int rlen) +int __cpcmd(const char *cmd, char *response, int rlen, int *response_code) { const int mask = 0x40000000L; unsigned long flags; + int return_code; + int return_len; int cmdlen; spin_lock_irqsave(&cpcmd_lock, flags); cmdlen = strlen(cmd); BUG_ON(cmdlen > 240); - strcpy(cpcmd_buf, cmd); + memcpy(cpcmd_buf, cmd, cmdlen); ASCEBC(cpcmd_buf, cmdlen); if (response != NULL && rlen > 0) { memset(response, 0, rlen); #ifndef CONFIG_ARCH_S390X - asm volatile ("LRA 2,0(%0)\n\t" - "LR 4,%1\n\t" - "O 4,%4\n\t" - "LRA 3,0(%2)\n\t" - "LR 5,%3\n\t" - ".long 0x83240008 # Diagnose X'08'\n\t" - : /* no output */ - : "a" (cpcmd_buf), "d" (cmdlen), - "a" (response), "d" (rlen), "m" (mask) - : "cc", "2", "3", "4", "5" ); + asm volatile ( "lra 2,0(%2)\n" + "lr 4,%3\n" + "o 4,%6\n" + "lra 3,0(%4)\n" + "lr 5,%5\n" + "diag 2,4,0x8\n" + "brc 8, .Litfits\n" + "ar 5, %5\n" + ".Litfits: \n" + "lr %0,4\n" + "lr %1,5\n" + : "=d" (return_code), "=d" (return_len) + : "a" (cpcmd_buf), "d" (cmdlen), + "a" (response), "d" (rlen), "m" (mask) + : "cc", "2", "3", "4", "5" ); #else /* CONFIG_ARCH_S390X */ - asm volatile (" lrag 2,0(%0)\n" - " lgr 4,%1\n" - " o 4,%4\n" - " lrag 3,0(%2)\n" - " lgr 5,%3\n" - " sam31\n" - " .long 0x83240008 # Diagnose X'08'\n" - " sam64" - : /* no output */ - : "a" (cpcmd_buf), "d" (cmdlen), - "a" (response), "d" (rlen), "m" (mask) - : "cc", "2", "3", "4", "5" ); + asm volatile ( "lrag 2,0(%2)\n" + "lgr 4,%3\n" + "o 4,%6\n" + "lrag 3,0(%4)\n" + "lgr 5,%5\n" + "sam31\n" + "diag 2,4,0x8\n" + "sam64\n" + "brc 8, .Litfits\n" + "agr 5, %5\n" + ".Litfits: \n" + "lgr %0,4\n" + "lgr %1,5\n" + : "=d" (return_code), "=d" (return_len) + : "a" (cpcmd_buf), "d" (cmdlen), + "a" (response), "d" (rlen), "m" (mask) + : "cc", "2", "3", "4", "5" ); #endif /* CONFIG_ARCH_S390X */ EBCASC(response, rlen); } else { + return_len = 0; #ifndef CONFIG_ARCH_S390X - asm volatile ("LRA 2,0(%0)\n\t" - "LR 3,%1\n\t" - ".long 0x83230008 # Diagnose X'08'\n\t" - : /* no output */ - : "a" (cpcmd_buf), "d" (cmdlen) - : "2", "3" ); + asm volatile ( "lra 2,0(%1)\n" + "lr 3,%2\n" + "diag 2,3,0x8\n" + "lr %0,3\n" + : "=d" (return_code) + : "a" (cpcmd_buf), "d" (cmdlen) + : "2", "3" ); #else /* CONFIG_ARCH_S390X */ - asm volatile (" lrag 2,0(%0)\n" - " lgr 3,%1\n" - " sam31\n" - " .long 0x83230008 # Diagnose X'08'\n" - " sam64" - : /* no output */ - : "a" (cpcmd_buf), "d" (cmdlen) - : "2", "3" ); + asm volatile ( "lrag 2,0(%1)\n" + "lgr 3,%2\n" + "sam31\n" + "diag 2,3,0x8\n" + "sam64\n" + "lgr %0,3\n" + : "=d" (return_code) + : "a" (cpcmd_buf), "d" (cmdlen) + : "2", "3" ); #endif /* CONFIG_ARCH_S390X */ } spin_unlock_irqrestore(&cpcmd_lock, flags); + if (response_code != NULL) + *response_code = return_code; + return return_len; } EXPORT_SYMBOL(__cpcmd); #ifdef CONFIG_ARCH_S390X -void cpcmd(char *cmd, char *response, int rlen) +int cpcmd(const char *cmd, char *response, int rlen, int *response_code) { char *lowbuf; + int len; + if ((rlen == 0) || (response == NULL) || !((unsigned long)response >> 31)) - __cpcmd(cmd, response, rlen); + len = __cpcmd(cmd, response, rlen, response_code); else { lowbuf = kmalloc(rlen, GFP_KERNEL | GFP_DMA); if (!lowbuf) { printk(KERN_WARNING "cpcmd: could not allocate response buffer\n"); - return; + return -ENOMEM; } - __cpcmd(cmd, lowbuf, rlen); + len = __cpcmd(cmd, lowbuf, rlen, response_code); memcpy(response, lowbuf, rlen); kfree(lowbuf); } + return len; } EXPORT_SYMBOL(cpcmd); diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c index eb7be0ad717..b6d740ac0e6 100644 --- a/arch/s390/kernel/setup.c +++ b/arch/s390/kernel/setup.c @@ -198,11 +198,11 @@ static void __init conmode_default(void) char *ptr; if (MACHINE_IS_VM) { - __cpcmd("QUERY CONSOLE", query_buffer, 1024); + __cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL); console_devno = simple_strtoul(query_buffer + 5, NULL, 16); ptr = strstr(query_buffer, "SUBCHANNEL ="); console_irq = simple_strtoul(ptr + 13, NULL, 16); - __cpcmd("QUERY TERM", query_buffer, 1024); + __cpcmd("QUERY TERM", query_buffer, 1024, NULL); ptr = strstr(query_buffer, "CONMODE"); /* * Set the conmode to 3215 so that the device recognition @@ -211,7 +211,7 @@ static void __init conmode_default(void) * 3215 and the 3270 driver will try to access the console * device (3215 as console and 3270 as normal tty). */ - __cpcmd("TERM CONMODE 3215", NULL, 0); + __cpcmd("TERM CONMODE 3215", NULL, 0, NULL); if (ptr == NULL) { #if defined(CONFIG_SCLP_CONSOLE) SET_CONSOLE_SCLP; diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index 50c335067cf..642572a8e33 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -284,7 +284,7 @@ static void do_machine_restart(void * __unused) * locks are always held disabled). */ if (MACHINE_IS_VM) - cpcmd ("IPL", NULL, 0); + cpcmd ("IPL", NULL, 0, NULL); else reipl (0x10000 | S390_lowcore.ipl_device); } @@ -313,7 +313,7 @@ static void do_machine_halt(void * __unused) if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid) == 0) { smp_send_stop(); if (MACHINE_IS_VM && strlen(vmhalt_cmd) > 0) - cpcmd(vmhalt_cmd, NULL, 0); + cpcmd(vmhalt_cmd, NULL, 0, NULL); signal_processor(smp_processor_id(), sigp_stop_and_store_status); } @@ -332,7 +332,7 @@ static void do_machine_power_off(void * __unused) if (atomic_compare_and_swap(-1, smp_processor_id(), &cpuid) == 0) { smp_send_stop(); if (MACHINE_IS_VM && strlen(vmpoff_cmd) > 0) - cpcmd(vmpoff_cmd, NULL, 0); + cpcmd(vmpoff_cmd, NULL, 0, NULL); signal_processor(smp_processor_id(), sigp_stop_and_store_status); } diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c index ca34b6f34b3..bc7b7be7acb 100644 --- a/arch/s390/kernel/traps.c +++ b/arch/s390/kernel/traps.c @@ -735,7 +735,7 @@ void __init trap_init(void) &ext_int_pfault); #endif #ifndef CONFIG_ARCH_S390X - cpcmd("SET PAGEX ON", NULL, 0); + cpcmd("SET PAGEX ON", NULL, 0, NULL); #endif } } diff --git a/arch/s390/mm/extmem.c b/arch/s390/mm/extmem.c index 648deed17e2..c5348108ca3 100644 --- a/arch/s390/mm/extmem.c +++ b/arch/s390/mm/extmem.c @@ -576,8 +576,8 @@ segment_save(char *name) segtype_string[seg->range[i].start & 0xff]); } sprintf(cmd2, "SAVESEG %s", name); - cpcmd(cmd1, NULL, 0); - cpcmd(cmd2, NULL, 0); + cpcmd(cmd1, NULL, 0, NULL); + cpcmd(cmd2, NULL, 0, NULL); spin_unlock(&dcss_lock); } diff --git a/drivers/s390/Kconfig b/drivers/s390/Kconfig index 96413c2cd1a..a86a650f3d6 100644 --- a/drivers/s390/Kconfig +++ b/drivers/s390/Kconfig @@ -187,6 +187,13 @@ config VMLOGRDR *SYMPTOM. This driver depends on the IUCV support driver. +config VMCP + tristate "Support for the z/VM CP interface (VM only)" + help + Select this option if you want to be able to interact with the control + program on z/VM + + config MONREADER tristate "API for reading z/VM monitor service records" depends on IUCV diff --git a/drivers/s390/char/Makefile b/drivers/s390/char/Makefile index 14e8cce9f86..6377a96735d 100644 --- a/drivers/s390/char/Makefile +++ b/drivers/s390/char/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_SCLP_CPI) += sclp_cpi.o obj-$(CONFIG_ZVM_WATCHDOG) += vmwatchdog.o obj-$(CONFIG_VMLOGRDR) += vmlogrdr.o +obj-$(CONFIG_VMCP) += vmcp.o tape-$(CONFIG_S390_TAPE_BLOCK) += tape_block.o tape-$(CONFIG_PROC_FS) += tape_proc.o diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c index 022f17bff73..f11a67fda40 100644 --- a/drivers/s390/char/con3215.c +++ b/drivers/s390/char/con3215.c @@ -860,8 +860,8 @@ con3215_init(void) /* Set the console mode for VM */ if (MACHINE_IS_VM) { - cpcmd("TERM CONMODE 3215", NULL, 0); - cpcmd("TERM AUTOCR OFF", NULL, 0); + cpcmd("TERM CONMODE 3215", NULL, 0, NULL); + cpcmd("TERM AUTOCR OFF", NULL, 0, NULL); } /* allocate 3215 request structures */ diff --git a/drivers/s390/char/con3270.c b/drivers/s390/char/con3270.c index d52fb57a6b1..fc7a213e591 100644 --- a/drivers/s390/char/con3270.c +++ b/drivers/s390/char/con3270.c @@ -591,8 +591,8 @@ con3270_init(void) /* Set the console mode for VM */ if (MACHINE_IS_VM) { - cpcmd("TERM CONMODE 3270", 0, 0); - cpcmd("TERM AUTOCR OFF", 0, 0); + cpcmd("TERM CONMODE 3270", NULL, 0, NULL); + cpcmd("TERM AUTOCR OFF", NULL, 0, NULL); } cdev = ccw_device_probe_console(); diff --git a/drivers/s390/char/vmcp.c b/drivers/s390/char/vmcp.c new file mode 100644 index 00000000000..dfbbf235ca2 --- /dev/null +++ b/drivers/s390/char/vmcp.c @@ -0,0 +1,219 @@ +/* + * Copyright (C) 2004,2005 IBM Corporation + * Interface implementation for communication with the v/VM control program + * Author(s): Christian Borntraeger + * + * + * z/VMs CP offers the possibility to issue commands via the diagnose code 8 + * this driver implements a character device that issues these commands and + * returns the answer of CP. + + * The idea of this driver is based on cpint from Neale Ferguson and #CP in CMS + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include "vmcp.h" + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Christian Borntraeger "); +MODULE_DESCRIPTION("z/VM CP interface"); + +static debug_info_t *vmcp_debug; + +static int vmcp_open(struct inode *inode, struct file *file) +{ + struct vmcp_session *session; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + session = kmalloc(sizeof(*session), GFP_KERNEL); + if (!session) + return -ENOMEM; + session->bufsize = PAGE_SIZE; + session->response = NULL; + session->resp_size = 0; + init_MUTEX(&session->mutex); + file->private_data = session; + return nonseekable_open(inode, file); +} + +static int vmcp_release(struct inode *inode, struct file *file) +{ + struct vmcp_session *session; + + session = (struct vmcp_session *)file->private_data; + file->private_data = NULL; + free_pages((unsigned long)session->response, get_order(session->bufsize)); + kfree(session); + return 0; +} + +static ssize_t +vmcp_read(struct file *file, char __user * buff, size_t count, loff_t * ppos) +{ + size_t tocopy; + struct vmcp_session *session; + + session = (struct vmcp_session *)file->private_data; + if (down_interruptible(&session->mutex)) + return -ERESTARTSYS; + if (!session->response) { + up(&session->mutex); + return 0; + } + if (*ppos > session->resp_size) { + up(&session->mutex); + return 0; + } + tocopy = min(session->resp_size - (size_t) (*ppos), count); + tocopy = min(tocopy,session->bufsize - (size_t) (*ppos)); + + if (copy_to_user(buff, session->response + (*ppos), tocopy)) { + up(&session->mutex); + return -EFAULT; + } + up(&session->mutex); + *ppos += tocopy; + return tocopy; +} + +static ssize_t +vmcp_write(struct file *file, const char __user * buff, size_t count, + loff_t * ppos) +{ + char *cmd; + struct vmcp_session *session; + + if (count > 240) + return -EINVAL; + cmd = kmalloc(count + 1, GFP_KERNEL); + if (!cmd) + return -ENOMEM; + if (copy_from_user(cmd, buff, count)) { + kfree(cmd); + return -EFAULT; + } + cmd[count] = '\0'; + session = (struct vmcp_session *)file->private_data; + if (down_interruptible(&session->mutex)) + return -ERESTARTSYS; + if (!session->response) + session->response = (char *)__get_free_pages(GFP_KERNEL + | __GFP_REPEAT | GFP_DMA, + get_order(session->bufsize)); + if (!session->response) { + up(&session->mutex); + kfree(cmd); + return -ENOMEM; + } + debug_text_event(vmcp_debug, 1, cmd); + session->resp_size = cpcmd(cmd, session->response, + session->bufsize, + &session->resp_code); + up(&session->mutex); + kfree(cmd); + *ppos = 0; /* reset the file pointer after a command */ + return count; +} + + +/* + * These ioctls are available, as the semantics of the diagnose 8 call + * does not fit very well into a Linux call. Diagnose X'08' is described in + * CP Programming Services SC24-6084-00 + * + * VMCP_GETCODE: gives the CP return code back to user space + * VMCP_SETBUF: sets the response buffer for the next write call. diagnose 8 + * expects adjacent pages in real storage and to make matters worse, we + * dont know the size of the response. Therefore we default to PAGESIZE and + * let userspace to change the response size, if userspace expects a bigger + * response + */ +static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct vmcp_session *session; + int temp; + + session = (struct vmcp_session *)file->private_data; + if (down_interruptible(&session->mutex)) + return -ERESTARTSYS; + switch (cmd) { + case VMCP_GETCODE: + temp = session->resp_code; + up(&session->mutex); + return put_user(temp, (int __user *)arg); + case VMCP_SETBUF: + free_pages((unsigned long)session->response, + get_order(session->bufsize)); + session->response=NULL; + temp = get_user(session->bufsize, (int __user *)arg); + if (get_order(session->bufsize) > 8) { + session->bufsize = PAGE_SIZE; + temp = -EINVAL; + } + up(&session->mutex); + return temp; + case VMCP_GETSIZE: + temp = session->resp_size; + up(&session->mutex); + return put_user(temp, (int __user *)arg); + default: + up(&session->mutex); + return -ENOIOCTLCMD; + } +} + +static struct file_operations vmcp_fops = { + .owner = THIS_MODULE, + .open = &vmcp_open, + .release = &vmcp_release, + .read = &vmcp_read, + .llseek = &no_llseek, + .write = &vmcp_write, + .unlocked_ioctl = &vmcp_ioctl, + .compat_ioctl = &vmcp_ioctl +}; + +static struct miscdevice vmcp_dev = { + .name = "vmcp", + .minor = MISC_DYNAMIC_MINOR, + .fops = &vmcp_fops, +}; + +static int __init vmcp_init(void) +{ + int ret; + + if (!MACHINE_IS_VM) { + printk(KERN_WARNING + "z/VM CP interface is only available under z/VM\n"); + return -ENODEV; + } + ret = misc_register(&vmcp_dev); + if (!ret) + printk(KERN_INFO "z/VM CP interface loaded\n"); + else + printk(KERN_WARNING + "z/VM CP interface not loaded. Could not register misc device.\n"); + vmcp_debug = debug_register("vmcp", 0, 1, 240); + debug_register_view(vmcp_debug, &debug_hex_ascii_view); + return ret; +} + +static void __exit vmcp_exit(void) +{ + WARN_ON(misc_deregister(&vmcp_dev) != 0); + debug_unregister(vmcp_debug); + printk(KERN_INFO "z/VM CP interface unloaded.\n"); +} + +module_init(vmcp_init); +module_exit(vmcp_exit); diff --git a/drivers/s390/char/vmcp.h b/drivers/s390/char/vmcp.h new file mode 100644 index 00000000000..87389e73046 --- /dev/null +++ b/drivers/s390/char/vmcp.h @@ -0,0 +1,30 @@ +/* + * Copyright (C) 2004, 2005 IBM Corporation + * Interface implementation for communication with the v/VM control program + * Version 1.0 + * Author(s): Christian Borntraeger + * + * + * z/VMs CP offers the possibility to issue commands via the diagnose code 8 + * this driver implements a character device that issues these commands and + * returns the answer of CP. + * + * The idea of this driver is based on cpint from Neale Ferguson + */ + +#include +#include + +#define VMCP_GETCODE _IOR(0x10, 1, int) +#define VMCP_SETBUF _IOW(0x10, 2, int) +#define VMCP_GETSIZE _IOR(0x10, 3, int) + +struct vmcp_session { + unsigned int bufsize; + char *response; + int resp_size; + int resp_code; + /* As we use copy_from/to_user, which might * + * sleep and cannot use a spinlock */ + struct semaphore mutex; +}; diff --git a/drivers/s390/char/vmlogrdr.c b/drivers/s390/char/vmlogrdr.c index f7717327d15..491f00c032e 100644 --- a/drivers/s390/char/vmlogrdr.c +++ b/drivers/s390/char/vmlogrdr.c @@ -236,7 +236,7 @@ vmlogrdr_get_recording_class_AB(void) { int len,i; printk (KERN_DEBUG "vmlogrdr: query command: %s\n", cp_command); - cpcmd(cp_command, cp_response, sizeof(cp_response)); + cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); printk (KERN_DEBUG "vmlogrdr: response: %s", cp_response); len = strnlen(cp_response,sizeof(cp_response)); // now the parsing @@ -288,7 +288,7 @@ vmlogrdr_recording(struct vmlogrdr_priv_t * logptr, int action, int purge) { printk (KERN_DEBUG "vmlogrdr: recording command: %s\n", cp_command); - cpcmd(cp_command, cp_response, sizeof(cp_response)); + cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); printk (KERN_DEBUG "vmlogrdr: recording response: %s", cp_response); } @@ -301,7 +301,7 @@ vmlogrdr_recording(struct vmlogrdr_priv_t * logptr, int action, int purge) { qid_string); printk (KERN_DEBUG "vmlogrdr: recording command: %s\n", cp_command); - cpcmd(cp_command, cp_response, sizeof(cp_response)); + cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); printk (KERN_DEBUG "vmlogrdr: recording response: %s", cp_response); /* The recording command will usually answer with 'Command complete' @@ -607,7 +607,7 @@ vmlogrdr_purge_store(struct device * dev, struct device_attribute *attr, const c priv->recording_name); printk (KERN_DEBUG "vmlogrdr: recording command: %s\n", cp_command); - cpcmd(cp_command, cp_response, sizeof(cp_response)); + cpcmd(cp_command, cp_response, sizeof(cp_response), NULL); printk (KERN_DEBUG "vmlogrdr: recording response: %s", cp_response); @@ -682,7 +682,7 @@ vmlogrdr_recording_status_show(struct device_driver *driver, char *buf) { char cp_command[] = "QUERY RECORDING "; int len; - cpcmd(cp_command, buf, 4096); + cpcmd(cp_command, buf, 4096, NULL); len = strlen(buf); return len; } diff --git a/drivers/s390/net/smsgiucv.c b/drivers/s390/net/smsgiucv.c index 1e3f7f3c662..d6469baa7e1 100644 --- a/drivers/s390/net/smsgiucv.c +++ b/drivers/s390/net/smsgiucv.c @@ -138,7 +138,7 @@ static void __exit smsg_exit(void) { if (smsg_handle > 0) { - cpcmd("SET SMSG OFF", 0, 0); + cpcmd("SET SMSG OFF", NULL, 0, NULL); iucv_sever(smsg_pathid, 0); iucv_unregister_program(smsg_handle); driver_unregister(&smsg_driver); @@ -177,7 +177,7 @@ smsg_init(void) smsg_handle = 0; return -EIO; } - cpcmd("SET SMSG IUCV", 0, 0); + cpcmd("SET SMSG IUCV", NULL, 0, NULL); return 0; } diff --git a/include/asm-s390/cpcmd.h b/include/asm-s390/cpcmd.h index 1d33c5da083..1fcf65be7a2 100644 --- a/include/asm-s390/cpcmd.h +++ b/include/asm-s390/cpcmd.h @@ -11,14 +11,28 @@ #define __CPCMD__ /* + * the lowlevel function for cpcmd * the caller of __cpcmd has to ensure that the response buffer is below 2 GB */ -extern void __cpcmd(char *cmd, char *response, int rlen); +extern int __cpcmd(const char *cmd, char *response, int rlen, int *response_code); #ifndef __s390x__ #define cpcmd __cpcmd #else -extern void cpcmd(char *cmd, char *response, int rlen); +/* + * cpcmd is the in-kernel interface for issuing CP commands + * + * cmd: null-terminated command string, max 240 characters + * response: response buffer for VM's textual response + * rlen: size of the response buffer, cpcmd will not exceed this size + * but will cap the output, if its too large. Everything that + * did not fit into the buffer will be silently dropped + * response_code: return pointer for VM's error code + * return value: the size of the response. The caller can check if the buffer + * was large enough by comparing the return value and rlen + * NOTE: If the response buffer is not below 2 GB, cpcmd can sleep + */ +extern int cpcmd(const char *cmd, char *response, int rlen, int *response_code); #endif /*__s390x__*/ #endif