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1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * hvcserver.c | |
4 | * Copyright (C) 2004 Ryan S Arnold, IBM Corporation | |
5 | * | |
6 | * PPC64 virtual I/O console server support. | |
1da177e4 LT |
7 | */ |
8 | ||
9 | #include <linux/kernel.h> | |
10 | #include <linux/list.h> | |
11 | #include <linux/module.h> | |
4e57b681 | 12 | #include <linux/slab.h> |
6b6680c4 | 13 | #include <linux/string.h> |
4e57b681 | 14 | |
1da177e4 LT |
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 | */ | |
8446196a | 31 | static int hvcs_convert(long to_convert) |
1da177e4 LT |
32 | { |
33 | switch (to_convert) { | |
706c8c93 | 34 | case H_SUCCESS: |
1da177e4 | 35 | return 0; |
706c8c93 | 36 | case H_PARAMETER: |
1da177e4 | 37 | return -EINVAL; |
706c8c93 | 38 | case H_HARDWARE: |
1da177e4 | 39 | return -EIO; |
706c8c93 SB |
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: | |
1da177e4 | 47 | return -EBUSY; |
706c8c93 | 48 | case H_FUNCTION: /* fall through */ |
1da177e4 LT |
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 */ | |
8446196a | 82 | static int hvcs_next_partner(uint32_t unit_address, |
1da177e4 LT |
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 | ||
1da177e4 LT |
132 | /* invalid parameters */ |
133 | if (!head || !pi_buff) | |
134 | return -EINVAL; | |
135 | ||
c13e1c05 | 136 | memset(pi_buff, 0x00, PAGE_SIZE); |
1da177e4 LT |
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 | ||
587870e8 TF |
153 | last_p_partition_ID = be64_to_cpu(pi_buff[0]); |
154 | last_p_unit_address = be64_to_cpu(pi_buff[1]); | |
1da177e4 LT |
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 */ | |
6b6680c4 | 179 | strlcpy(&next_partner_info->location_code[0], |
1da177e4 | 180 | (char *)&pi_buff[2], |
6b6680c4 | 181 | sizeof(next_partner_info->location_code)); |
1da177e4 LT |
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); |