Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Copyright IBM Corp. 2004, 2010
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * Interface implementation for communication with the z/VM control program
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * Author(s): Christian Borntraeger <borntraeger@de.ibm.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * z/VMs CP offers the possibility to issue commands via the diagnose code 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  * this driver implements a character device that issues these commands and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  * returns the answer of CP.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12)  * The idea of this driver is based on cpint from Neale Ferguson and #CP in CMS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <linux/compat.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <linux/miscdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <linux/uaccess.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) #include <linux/mutex.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) #include <linux/cma.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) #include <asm/cpcmd.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) #include <asm/debug.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) #include <asm/vmcp.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) struct vmcp_session {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) 	char *response;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) 	unsigned int bufsize;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	unsigned int cma_alloc : 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	int resp_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	int resp_code;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	struct mutex mutex;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) static debug_info_t *vmcp_debug;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) static unsigned long vmcp_cma_size __initdata = CONFIG_VMCP_CMA_SIZE * 1024 * 1024;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) static struct cma *vmcp_cma;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) static int __init early_parse_vmcp_cma(char *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 	if (!p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 		return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 	vmcp_cma_size = ALIGN(memparse(p, NULL), PAGE_SIZE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) early_param("vmcp_cma", early_parse_vmcp_cma);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) void __init vmcp_cma_reserve(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	if (!MACHINE_IS_VM)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	cma_declare_contiguous(0, vmcp_cma_size, 0, 0, 0, false, "vmcp", &vmcp_cma);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) static void vmcp_response_alloc(struct vmcp_session *session)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	struct page *page = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	int nr_pages, order;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) 	order = get_order(session->bufsize);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 	nr_pages = ALIGN(session->bufsize, PAGE_SIZE) >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) 	 * For anything below order 3 allocations rely on the buddy
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	 * allocator. If such low-order allocations can't be handled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	 * anymore the system won't work anyway.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	if (order > 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 		page = cma_alloc(vmcp_cma, nr_pages, 0, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	if (page) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 		session->response = (char *)page_to_phys(page);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 		session->cma_alloc = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 	session->response = (char *)__get_free_pages(GFP_KERNEL | __GFP_RETRY_MAYFAIL, order);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) static void vmcp_response_free(struct vmcp_session *session)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 	int nr_pages, order;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	struct page *page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	if (!session->response)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	order = get_order(session->bufsize);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 	nr_pages = ALIGN(session->bufsize, PAGE_SIZE) >> PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 	if (session->cma_alloc) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 		page = phys_to_page((unsigned long)session->response);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		cma_release(vmcp_cma, page, nr_pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		session->cma_alloc = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		free_pages((unsigned long)session->response, order);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	session->response = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) static int vmcp_open(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	struct vmcp_session *session;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	if (!capable(CAP_SYS_ADMIN))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		return -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 	session = kmalloc(sizeof(*session), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	if (!session)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 	session->bufsize = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 	session->response = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 	session->resp_size = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	mutex_init(&session->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 	file->private_data = session;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 	return nonseekable_open(inode, file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) static int vmcp_release(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 	struct vmcp_session *session;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 	session = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	file->private_data = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	vmcp_response_free(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	kfree(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) static ssize_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) vmcp_read(struct file *file, char __user *buff, size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	ssize_t ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 	size_t size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 	struct vmcp_session *session;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	session = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 	if (mutex_lock_interruptible(&session->mutex))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 		return -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	if (!session->response) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 		mutex_unlock(&session->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	size = min_t(size_t, session->resp_size, session->bufsize);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	ret = simple_read_from_buffer(buff, count, ppos,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 					session->response, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 	mutex_unlock(&session->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) static ssize_t
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) vmcp_write(struct file *file, const char __user *buff, size_t count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 	   loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	char *cmd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 	struct vmcp_session *session;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	if (count > 240)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	cmd = memdup_user_nul(buff, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 	if (IS_ERR(cmd))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 		return PTR_ERR(cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	session = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	if (mutex_lock_interruptible(&session->mutex)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 		kfree(cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		return -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	if (!session->response)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 		vmcp_response_alloc(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	if (!session->response) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 		mutex_unlock(&session->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 		kfree(cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	debug_text_event(vmcp_debug, 1, cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	session->resp_size = cpcmd(cmd, session->response, session->bufsize,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 				   &session->resp_code);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	mutex_unlock(&session->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	kfree(cmd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 	*ppos = 0;		/* reset the file pointer after a command */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)  * These ioctls are available, as the semantics of the diagnose 8 call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)  * does not fit very well into a Linux call. Diagnose X'08' is described in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)  * CP Programming Services SC24-6084-00
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193)  * VMCP_GETCODE: gives the CP return code back to user space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194)  * VMCP_SETBUF: sets the response buffer for the next write call. diagnose 8
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195)  * expects adjacent pages in real storage and to make matters worse, we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)  * dont know the size of the response. Therefore we default to PAGESIZE and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)  * let userspace to change the response size, if userspace expects a bigger
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198)  * response
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) static long vmcp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	struct vmcp_session *session;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 	int ret = -ENOTTY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 	int __user *argp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 	session = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 	if (is_compat_task())
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 		argp = compat_ptr(arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 	else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 		argp = (int __user *)arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	if (mutex_lock_interruptible(&session->mutex))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 		return -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 	switch (cmd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 	case VMCP_GETCODE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 		ret = put_user(session->resp_code, argp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	case VMCP_SETBUF:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 		vmcp_response_free(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 		ret = get_user(session->bufsize, argp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 			session->bufsize = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 		if (!session->bufsize || get_order(session->bufsize) > 8) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 			session->bufsize = PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 			ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	case VMCP_GETSIZE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		ret = put_user(session->resp_size, argp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 	default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 	mutex_unlock(&session->mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) static const struct file_operations vmcp_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	.owner		= THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	.open		= vmcp_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	.release	= vmcp_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 	.read		= vmcp_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 	.write		= vmcp_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	.unlocked_ioctl	= vmcp_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	.compat_ioctl	= vmcp_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	.llseek		= no_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) static struct miscdevice vmcp_dev = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 	.name	= "vmcp",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 	.minor	= MISC_DYNAMIC_MINOR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	.fops	= &vmcp_fops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) static int __init vmcp_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	if (!MACHINE_IS_VM)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 	vmcp_debug = debug_register("vmcp", 1, 1, 240);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	if (!vmcp_debug)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	ret = debug_register_view(vmcp_debug, &debug_hex_ascii_view);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 		debug_unregister(vmcp_debug);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	ret = misc_register(&vmcp_dev);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 		debug_unregister(vmcp_debug);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) device_initcall(vmcp_init);