1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * hvcserver.c 4 * Copyright (C) 2004 Ryan S Arnold, IBM Corporation 5 * 6 * PPC64 virtual I/O console server support. 7 */ 8 9 #include <linux/kernel.h> 10 #include <linux/list.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/string.h> 14 15 #include <asm/hvcall.h> 16 #include <asm/hvcserver.h> 17 #include <asm/io.h> 18 19 #define HVCS_ARCH_VERSION "1.0.0" 20 21 MODULE_AUTHOR("Ryan S. Arnold <rsa@us.ibm.com>"); 22 MODULE_DESCRIPTION("IBM hvcs ppc64 API"); 23 MODULE_LICENSE("GPL"); 24 MODULE_VERSION(HVCS_ARCH_VERSION); 25 26 /* 27 * Convert arch specific return codes into relevant errnos. The hvcs 28 * functions aren't performance sensitive, so this conversion isn't an 29 * issue. 30 */ 31 static int hvcs_convert(long to_convert) 32 { 33 switch (to_convert) { 34 case H_SUCCESS: 35 return 0; 36 case H_PARAMETER: 37 return -EINVAL; 38 case H_HARDWARE: 39 return -EIO; 40 case H_BUSY: 41 case H_LONG_BUSY_ORDER_1_MSEC: 42 case H_LONG_BUSY_ORDER_10_MSEC: 43 case H_LONG_BUSY_ORDER_100_MSEC: 44 case H_LONG_BUSY_ORDER_1_SEC: 45 case H_LONG_BUSY_ORDER_10_SEC: 46 case H_LONG_BUSY_ORDER_100_SEC: 47 return -EBUSY; 48 case H_FUNCTION: 49 default: 50 return -EPERM; 51 } 52 } 53 54 /** 55 * hvcs_free_partner_info - free pi allocated by hvcs_get_partner_info 56 * @head: list_head pointer for an allocated list of partner info structs to 57 * free. 58 * 59 * This function is used to free the partner info list that was returned by 60 * calling hvcs_get_partner_info(). 61 */ 62 int hvcs_free_partner_info(struct list_head *head) 63 { 64 struct hvcs_partner_info *pi; 65 struct list_head *element; 66 67 if (!head) 68 return -EINVAL; 69 70 while (!list_empty(head)) { 71 element = head->next; 72 pi = list_entry(element, struct hvcs_partner_info, node); 73 list_del(element); 74 kfree(pi); 75 } 76 77 return 0; 78 } 79 EXPORT_SYMBOL(hvcs_free_partner_info); 80 81 /* Helper function for hvcs_get_partner_info */ 82 static int hvcs_next_partner(uint32_t unit_address, 83 unsigned long last_p_partition_ID, 84 unsigned long last_p_unit_address, unsigned long *pi_buff) 85 86 { 87 long retval; 88 retval = plpar_hcall_norets(H_VTERM_PARTNER_INFO, unit_address, 89 last_p_partition_ID, 90 last_p_unit_address, virt_to_phys(pi_buff)); 91 return hvcs_convert(retval); 92 } 93 94 /** 95 * hvcs_get_partner_info - Get all of the partner info for a vty-server adapter 96 * @unit_address: The unit_address of the vty-server adapter for which this 97 * function is fetching partner info. 98 * @head: An initialized list_head pointer to an empty list to use to return the 99 * list of partner info fetched from the hypervisor to the caller. 100 * @pi_buff: A page sized buffer pre-allocated prior to calling this function 101 * that is to be used to be used by firmware as an iterator to keep track 102 * of the partner info retrieval. 103 * 104 * This function returns non-zero on success, or if there is no partner info. 105 * 106 * The pi_buff is pre-allocated prior to calling this function because this 107 * function may be called with a spin_lock held and kmalloc of a page is not 108 * recommended as GFP_ATOMIC. 109 * 110 * The first long of this buffer is used to store a partner unit address. The 111 * second long is used to store a partner partition ID and starting at 112 * pi_buff[2] is the 79 character Converged Location Code (diff size than the 113 * unsigned longs, hence the casting mumbo jumbo you see later). 114 * 115 * Invocation of this function should always be followed by an invocation of 116 * hvcs_free_partner_info() using a pointer to the SAME list head instance 117 * that was passed as a parameter to this function. 118 */ 119 int hvcs_get_partner_info(uint32_t unit_address, struct list_head *head, 120 unsigned long *pi_buff) 121 { 122 /* 123 * Dealt with as longs because of the hcall interface even though the 124 * values are uint32_t. 125 */ 126 unsigned long last_p_partition_ID; 127 unsigned long last_p_unit_address; 128 struct hvcs_partner_info *next_partner_info = NULL; 129 int more = 1; 130 int retval; 131 132 /* invalid parameters */ 133 if (!head || !pi_buff) 134 return -EINVAL; 135 136 memset(pi_buff, 0x00, PAGE_SIZE); 137 last_p_partition_ID = last_p_unit_address = ~0UL; 138 INIT_LIST_HEAD(head); 139 140 do { 141 retval = hvcs_next_partner(unit_address, last_p_partition_ID, 142 last_p_unit_address, pi_buff); 143 if (retval) { 144 /* 145 * Don't indicate that we've failed if we have 146 * any list elements. 147 */ 148 if (!list_empty(head)) 149 return 0; 150 return retval; 151 } 152 153 last_p_partition_ID = be64_to_cpu(pi_buff[0]); 154 last_p_unit_address = be64_to_cpu(pi_buff[1]); 155 156 /* This indicates that there are no further partners */ 157 if (last_p_partition_ID == ~0UL 158 && last_p_unit_address == ~0UL) 159 break; 160 161 /* This is a very small struct and will be freed soon in 162 * hvcs_free_partner_info(). */ 163 next_partner_info = kmalloc(sizeof(struct hvcs_partner_info), 164 GFP_ATOMIC); 165 166 if (!next_partner_info) { 167 printk(KERN_WARNING "HVCONSOLE: kmalloc() failed to" 168 " allocate partner info struct.\n"); 169 hvcs_free_partner_info(head); 170 return -ENOMEM; 171 } 172 173 next_partner_info->unit_address 174 = (unsigned int)last_p_unit_address; 175 next_partner_info->partition_ID 176 = (unsigned int)last_p_partition_ID; 177 178 /* copy the Null-term char too */ 179 strlcpy(&next_partner_info->location_code[0], 180 (char *)&pi_buff[2], 181 sizeof(next_partner_info->location_code)); 182 183 list_add_tail(&(next_partner_info->node), head); 184 next_partner_info = NULL; 185 186 } while (more); 187 188 return 0; 189 } 190 EXPORT_SYMBOL(hvcs_get_partner_info); 191 192 /** 193 * hvcs_register_connection - establish a connection between this vty-server and 194 * a vty. 195 * @unit_address: The unit address of the vty-server adapter that is to be 196 * establish a connection. 197 * @p_partition_ID: The partition ID of the vty adapter that is to be connected. 198 * @p_unit_address: The unit address of the vty adapter to which the vty-server 199 * is to be connected. 200 * 201 * If this function is called once and -EINVAL is returned it may 202 * indicate that the partner info needs to be refreshed for the 203 * target unit address at which point the caller must invoke 204 * hvcs_get_partner_info() and then call this function again. If, 205 * for a second time, -EINVAL is returned then it indicates that 206 * there is probably already a partner connection registered to a 207 * different vty-server adapter. It is also possible that a second 208 * -EINVAL may indicate that one of the parms is not valid, for 209 * instance if the link was removed between the vty-server adapter 210 * and the vty adapter that you are trying to open. Don't shoot the 211 * messenger. Firmware implemented it this way. 212 */ 213 int hvcs_register_connection( uint32_t unit_address, 214 uint32_t p_partition_ID, uint32_t p_unit_address) 215 { 216 long retval; 217 retval = plpar_hcall_norets(H_REGISTER_VTERM, unit_address, 218 p_partition_ID, p_unit_address); 219 return hvcs_convert(retval); 220 } 221 EXPORT_SYMBOL(hvcs_register_connection); 222 223 /** 224 * hvcs_free_connection - free the connection between a vty-server and vty 225 * @unit_address: The unit address of the vty-server that is to have its 226 * connection severed. 227 * 228 * This function is used to free the partner connection between a vty-server 229 * adapter and a vty adapter. 230 * 231 * If -EBUSY is returned continue to call this function until 0 is returned. 232 */ 233 int hvcs_free_connection(uint32_t unit_address) 234 { 235 long retval; 236 retval = plpar_hcall_norets(H_FREE_VTERM, unit_address); 237 return hvcs_convert(retval); 238 } 239 EXPORT_SYMBOL(hvcs_free_connection); 240