1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Functions for assembling fcx enabled I/O control blocks.
4 *
5 * Copyright IBM Corp. 2008
6 * Author(s): Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
7 */
8
9#include <linux/kernel.h>
10#include <linux/types.h>
11#include <linux/string.h>
12#include <linux/io.h>
13#include <linux/errno.h>
14#include <linux/err.h>
15#include <linux/module.h>
16#include <asm/fcx.h>
17#include "cio.h"
18
19/**
20 * tcw_get_intrg - return pointer to associated interrogate tcw
21 * @tcw: pointer to the original tcw
22 *
23 * Return a pointer to the interrogate tcw associated with the specified tcw
24 * or %NULL if there is no associated interrogate tcw.
25 */
26struct tcw *tcw_get_intrg(struct tcw *tcw)
27{
28 return phys_to_virt(address: tcw->intrg);
29}
30EXPORT_SYMBOL(tcw_get_intrg);
31
32/**
33 * tcw_get_data - return pointer to input/output data associated with tcw
34 * @tcw: pointer to the tcw
35 *
36 * Return the input or output data address specified in the tcw depending
37 * on whether the r-bit or the w-bit is set. If neither bit is set, return
38 * %NULL.
39 */
40void *tcw_get_data(struct tcw *tcw)
41{
42 if (tcw->r)
43 return phys_to_virt(address: tcw->input);
44 if (tcw->w)
45 return phys_to_virt(address: tcw->output);
46 return NULL;
47}
48EXPORT_SYMBOL(tcw_get_data);
49
50/**
51 * tcw_get_tccb - return pointer to tccb associated with tcw
52 * @tcw: pointer to the tcw
53 *
54 * Return pointer to the tccb associated with this tcw.
55 */
56struct tccb *tcw_get_tccb(struct tcw *tcw)
57{
58 return phys_to_virt(address: tcw->tccb);
59}
60EXPORT_SYMBOL(tcw_get_tccb);
61
62/**
63 * tcw_get_tsb - return pointer to tsb associated with tcw
64 * @tcw: pointer to the tcw
65 *
66 * Return pointer to the tsb associated with this tcw.
67 */
68struct tsb *tcw_get_tsb(struct tcw *tcw)
69{
70 return phys_to_virt(address: tcw->tsb);
71}
72EXPORT_SYMBOL(tcw_get_tsb);
73
74/**
75 * tcw_init - initialize tcw data structure
76 * @tcw: pointer to the tcw to be initialized
77 * @r: initial value of the r-bit
78 * @w: initial value of the w-bit
79 *
80 * Initialize all fields of the specified tcw data structure with zero and
81 * fill in the format, flags, r and w fields.
82 */
83void tcw_init(struct tcw *tcw, int r, int w)
84{
85 memset(tcw, 0, sizeof(struct tcw));
86 tcw->format = TCW_FORMAT_DEFAULT;
87 tcw->flags = TCW_FLAGS_TIDAW_FORMAT(TCW_TIDAW_FORMAT_DEFAULT);
88 if (r)
89 tcw->r = 1;
90 if (w)
91 tcw->w = 1;
92}
93EXPORT_SYMBOL(tcw_init);
94
95static inline size_t tca_size(struct tccb *tccb)
96{
97 return tccb->tcah.tcal - 12;
98}
99
100static u32 calc_dcw_count(struct tccb *tccb)
101{
102 int offset;
103 struct dcw *dcw;
104 u32 count = 0;
105 size_t size;
106
107 size = tca_size(tccb);
108 for (offset = 0; offset < size;) {
109 dcw = (struct dcw *) &tccb->tca[offset];
110 count += dcw->count;
111 if (!(dcw->flags & DCW_FLAGS_CC))
112 break;
113 offset += sizeof(struct dcw) + ALIGN((int) dcw->cd_count, 4);
114 }
115 return count;
116}
117
118static u32 calc_cbc_size(struct tidaw *tidaw, int num)
119{
120 int i;
121 u32 cbc_data;
122 u32 cbc_count = 0;
123 u64 data_count = 0;
124
125 for (i = 0; i < num; i++) {
126 if (tidaw[i].flags & TIDAW_FLAGS_LAST)
127 break;
128 /* TODO: find out if padding applies to total of data
129 * transferred or data transferred by this tidaw. Assumption:
130 * applies to total. */
131 data_count += tidaw[i].count;
132 if (tidaw[i].flags & TIDAW_FLAGS_INSERT_CBC) {
133 cbc_data = 4 + ALIGN(data_count, 4) - data_count;
134 cbc_count += cbc_data;
135 data_count += cbc_data;
136 }
137 }
138 return cbc_count;
139}
140
141/**
142 * tcw_finalize - finalize tcw length fields and tidaw list
143 * @tcw: pointer to the tcw
144 * @num_tidaws: the number of tidaws used to address input/output data or zero
145 * if no tida is used
146 *
147 * Calculate the input-/output-count and tccbl field in the tcw, add a
148 * tcat the tccb and terminate the data tidaw list if used.
149 *
150 * Note: in case input- or output-tida is used, the tidaw-list must be stored
151 * in contiguous storage (no ttic). The tcal field in the tccb must be
152 * up-to-date.
153 */
154void tcw_finalize(struct tcw *tcw, int num_tidaws)
155{
156 struct tidaw *tidaw;
157 struct tccb *tccb;
158 struct tccb_tcat *tcat;
159 u32 count;
160
161 /* Terminate tidaw list. */
162 tidaw = tcw_get_data(tcw);
163 if (num_tidaws > 0)
164 tidaw[num_tidaws - 1].flags |= TIDAW_FLAGS_LAST;
165 /* Add tcat to tccb. */
166 tccb = tcw_get_tccb(tcw);
167 tcat = (struct tccb_tcat *) &tccb->tca[tca_size(tccb)];
168 memset(tcat, 0, sizeof(*tcat));
169 /* Calculate tcw input/output count and tcat transport count. */
170 count = calc_dcw_count(tccb);
171 if (tcw->w && (tcw->flags & TCW_FLAGS_OUTPUT_TIDA))
172 count += calc_cbc_size(tidaw, num: num_tidaws);
173 if (tcw->r)
174 tcw->input_count = count;
175 else if (tcw->w)
176 tcw->output_count = count;
177 tcat->count = ALIGN(count, 4) + 4;
178 /* Calculate tccbl. */
179 tcw->tccbl = (sizeof(struct tccb) + tca_size(tccb) +
180 sizeof(struct tccb_tcat) - 20) >> 2;
181}
182EXPORT_SYMBOL(tcw_finalize);
183
184/**
185 * tcw_set_intrg - set the interrogate tcw address of a tcw
186 * @tcw: the tcw address
187 * @intrg_tcw: the address of the interrogate tcw
188 *
189 * Set the address of the interrogate tcw in the specified tcw.
190 */
191void tcw_set_intrg(struct tcw *tcw, struct tcw *intrg_tcw)
192{
193 tcw->intrg = (u32)virt_to_phys(address: intrg_tcw);
194}
195EXPORT_SYMBOL(tcw_set_intrg);
196
197/**
198 * tcw_set_data - set data address and tida flag of a tcw
199 * @tcw: the tcw address
200 * @data: the data address
201 * @use_tidal: zero of the data address specifies a contiguous block of data,
202 * non-zero if it specifies a list if tidaws.
203 *
204 * Set the input/output data address of a tcw (depending on the value of the
205 * r-flag and w-flag). If @use_tidal is non-zero, the corresponding tida flag
206 * is set as well.
207 */
208void tcw_set_data(struct tcw *tcw, void *data, int use_tidal)
209{
210 if (tcw->r) {
211 tcw->input = virt_to_phys(address: data);
212 if (use_tidal)
213 tcw->flags |= TCW_FLAGS_INPUT_TIDA;
214 } else if (tcw->w) {
215 tcw->output = virt_to_phys(address: data);
216 if (use_tidal)
217 tcw->flags |= TCW_FLAGS_OUTPUT_TIDA;
218 }
219}
220EXPORT_SYMBOL(tcw_set_data);
221
222/**
223 * tcw_set_tccb - set tccb address of a tcw
224 * @tcw: the tcw address
225 * @tccb: the tccb address
226 *
227 * Set the address of the tccb in the specified tcw.
228 */
229void tcw_set_tccb(struct tcw *tcw, struct tccb *tccb)
230{
231 tcw->tccb = virt_to_phys(address: tccb);
232}
233EXPORT_SYMBOL(tcw_set_tccb);
234
235/**
236 * tcw_set_tsb - set tsb address of a tcw
237 * @tcw: the tcw address
238 * @tsb: the tsb address
239 *
240 * Set the address of the tsb in the specified tcw.
241 */
242void tcw_set_tsb(struct tcw *tcw, struct tsb *tsb)
243{
244 tcw->tsb = virt_to_phys(address: tsb);
245}
246EXPORT_SYMBOL(tcw_set_tsb);
247
248/**
249 * tccb_init - initialize tccb
250 * @tccb: the tccb address
251 * @size: the maximum size of the tccb
252 * @sac: the service-action-code to be user
253 *
254 * Initialize the header of the specified tccb by resetting all values to zero
255 * and filling in defaults for format, sac and initial tcal fields.
256 */
257void tccb_init(struct tccb *tccb, size_t size, u32 sac)
258{
259 memset(tccb, 0, size);
260 tccb->tcah.format = TCCB_FORMAT_DEFAULT;
261 tccb->tcah.sac = sac;
262 tccb->tcah.tcal = 12;
263}
264EXPORT_SYMBOL(tccb_init);
265
266/**
267 * tsb_init - initialize tsb
268 * @tsb: the tsb address
269 *
270 * Initialize the specified tsb by resetting all values to zero.
271 */
272void tsb_init(struct tsb *tsb)
273{
274 memset(tsb, 0, sizeof(*tsb));
275}
276EXPORT_SYMBOL(tsb_init);
277
278/**
279 * tccb_add_dcw - add a dcw to the tccb
280 * @tccb: the tccb address
281 * @tccb_size: the maximum tccb size
282 * @cmd: the dcw command
283 * @flags: flags for the dcw
284 * @cd: pointer to control data for this dcw or NULL if none is required
285 * @cd_count: number of control data bytes for this dcw
286 * @count: number of data bytes for this dcw
287 *
288 * Add a new dcw to the specified tccb by writing the dcw information specified
289 * by @cmd, @flags, @cd, @cd_count and @count to the tca of the tccb. Return
290 * a pointer to the newly added dcw on success or -%ENOSPC if the new dcw
291 * would exceed the available space as defined by @tccb_size.
292 *
293 * Note: the tcal field of the tccb header will be updates to reflect added
294 * content.
295 */
296struct dcw *tccb_add_dcw(struct tccb *tccb, size_t tccb_size, u8 cmd, u8 flags,
297 void *cd, u8 cd_count, u32 count)
298{
299 struct dcw *dcw;
300 int size;
301 int tca_offset;
302
303 /* Check for space. */
304 tca_offset = tca_size(tccb);
305 size = ALIGN(sizeof(struct dcw) + cd_count, 4);
306 if (sizeof(struct tccb_tcah) + tca_offset + size +
307 sizeof(struct tccb_tcat) > tccb_size)
308 return ERR_PTR(error: -ENOSPC);
309 /* Add dcw to tca. */
310 dcw = (struct dcw *) &tccb->tca[tca_offset];
311 memset(dcw, 0, size);
312 dcw->cmd = cmd;
313 dcw->flags = flags;
314 dcw->count = count;
315 dcw->cd_count = cd_count;
316 if (cd)
317 memcpy(&dcw->cd[0], cd, cd_count);
318 tccb->tcah.tcal += size;
319 return dcw;
320}
321EXPORT_SYMBOL(tccb_add_dcw);
322
323/**
324 * tcw_add_tidaw - add a tidaw to a tcw
325 * @tcw: the tcw address
326 * @num_tidaws: the current number of tidaws
327 * @flags: flags for the new tidaw
328 * @addr: address value for the new tidaw
329 * @count: count value for the new tidaw
330 *
331 * Add a new tidaw to the input/output data tidaw-list of the specified tcw
332 * (depending on the value of the r-flag and w-flag) and return a pointer to
333 * the new tidaw.
334 *
335 * Note: the tidaw-list is assumed to be contiguous with no ttics. The caller
336 * must ensure that there is enough space for the new tidaw. The last-tidaw
337 * flag for the last tidaw in the list will be set by tcw_finalize.
338 */
339struct tidaw *tcw_add_tidaw(struct tcw *tcw, int num_tidaws, u8 flags,
340 void *addr, u32 count)
341{
342 struct tidaw *tidaw;
343
344 /* Add tidaw to tidaw-list. */
345 tidaw = ((struct tidaw *) tcw_get_data(tcw)) + num_tidaws;
346 memset(tidaw, 0, sizeof(struct tidaw));
347 tidaw->flags = flags;
348 tidaw->count = count;
349 tidaw->addr = virt_to_phys(address: addr);
350 return tidaw;
351}
352EXPORT_SYMBOL(tcw_add_tidaw);
353

source code of linux/drivers/s390/cio/fcx.c