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(entry: element); |
74 | kfree(objp: 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(address: pi_buff)); |
91 | return hvcs_convert(to_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(list: 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 | strscpy(&next_partner_info->location_code[0], |
180 | (char *)&pi_buff[2], |
181 | sizeof(next_partner_info->location_code)); |
182 | |
183 | list_add_tail(new: &(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(to_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(to_convert: retval); |
238 | } |
239 | EXPORT_SYMBOL(hvcs_free_connection); |
240 | |