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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * File...........: linux/include/asm-s390x/idals.h
3 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
4 * Martin Schwidefsky <schwidefsky@de.ibm.com>
5 * Bugreports.to..: <Linux390@de.ibm.com>
6 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 2000a
7
8 * History of changes
9 * 07/24/00 new file
10 * 05/04/02 code restructuring.
11 */
12
13#ifndef _S390_IDALS_H
14#define _S390_IDALS_H
15
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/errno.h>
17#include <linux/err.h>
18#include <linux/types.h>
19#include <linux/slab.h>
20#include <asm/cio.h>
21#include <asm/uaccess.h>
22
23#ifdef __s390x__
24#define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */
25#else
26#define IDA_SIZE_LOG 11 /* 11 for 2k , 12 for 4k */
27#endif
28#define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG)
29
30/*
31 * Test if an address/length pair needs an idal list.
32 */
33static inline int
34idal_is_needed(void *vaddr, unsigned int length)
35{
36#ifdef __s390x__
37 return ((__pa(vaddr) + length - 1) >> 31) != 0;
38#else
39 return 0;
40#endif
41}
42
43
44/*
45 * Return the number of idal words needed for an address/length pair.
46 */
Stefan Weinhuberf3eb5382009-03-26 15:23:48 +010047static inline unsigned int idal_nr_words(void *vaddr, unsigned int length)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
Stefan Weinhuberf3eb5382009-03-26 15:23:48 +010049 return ((__pa(vaddr) & (IDA_BLOCK_SIZE-1)) + length +
50 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
Linus Torvalds1da177e2005-04-16 15:20:36 -070051}
52
53/*
54 * Create the list of idal words for an address/length pair.
55 */
Stefan Weinhuberf3eb5382009-03-26 15:23:48 +010056static inline unsigned long *idal_create_words(unsigned long *idaws,
57 void *vaddr, unsigned int length)
Linus Torvalds1da177e2005-04-16 15:20:36 -070058{
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 unsigned long paddr;
60 unsigned int cidaw;
61
62 paddr = __pa(vaddr);
63 cidaw = ((paddr & (IDA_BLOCK_SIZE-1)) + length +
64 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
65 *idaws++ = paddr;
66 paddr &= -IDA_BLOCK_SIZE;
67 while (--cidaw > 0) {
68 paddr += IDA_BLOCK_SIZE;
69 *idaws++ = paddr;
70 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 return idaws;
72}
73
74/*
75 * Sets the address of the data in CCW.
76 * If necessary it allocates an IDAL and sets the appropriate flags.
77 */
78static inline int
79set_normalized_cda(struct ccw1 * ccw, void *vaddr)
80{
81#ifdef __s390x__
82 unsigned int nridaws;
83 unsigned long *idal;
84
85 if (ccw->flags & CCW_FLAG_IDA)
86 return -EINVAL;
87 nridaws = idal_nr_words(vaddr, ccw->count);
88 if (nridaws > 0) {
89 idal = kmalloc(nridaws * sizeof(unsigned long),
90 GFP_ATOMIC | GFP_DMA );
91 if (idal == NULL)
92 return -ENOMEM;
93 idal_create_words(idal, vaddr, ccw->count);
94 ccw->flags |= CCW_FLAG_IDA;
95 vaddr = idal;
96 }
97#endif
98 ccw->cda = (__u32)(unsigned long) vaddr;
99 return 0;
100}
101
102/*
103 * Releases any allocated IDAL related to the CCW.
104 */
105static inline void
106clear_normalized_cda(struct ccw1 * ccw)
107{
108#ifdef __s390x__
109 if (ccw->flags & CCW_FLAG_IDA) {
110 kfree((void *)(unsigned long) ccw->cda);
111 ccw->flags &= ~CCW_FLAG_IDA;
112 }
113#endif
114 ccw->cda = 0;
115}
116
117/*
118 * Idal buffer extension
119 */
120struct idal_buffer {
121 size_t size;
122 size_t page_order;
123 void *data[0];
124};
125
126/*
127 * Allocate an idal buffer
128 */
129static inline struct idal_buffer *
130idal_buffer_alloc(size_t size, int page_order)
131{
132 struct idal_buffer *ib;
133 int nr_chunks, nr_ptrs, i;
134
135 nr_ptrs = (size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
136 nr_chunks = (4096 << page_order) >> IDA_SIZE_LOG;
137 ib = kmalloc(sizeof(struct idal_buffer) + nr_ptrs*sizeof(void *),
138 GFP_DMA | GFP_KERNEL);
139 if (ib == NULL)
140 return ERR_PTR(-ENOMEM);
141 ib->size = size;
142 ib->page_order = page_order;
143 for (i = 0; i < nr_ptrs; i++) {
144 if ((i & (nr_chunks - 1)) != 0) {
145 ib->data[i] = ib->data[i-1] + IDA_BLOCK_SIZE;
146 continue;
147 }
148 ib->data[i] = (void *)
149 __get_free_pages(GFP_KERNEL, page_order);
150 if (ib->data[i] != NULL)
151 continue;
152 // Not enough memory
153 while (i >= nr_chunks) {
154 i -= nr_chunks;
155 free_pages((unsigned long) ib->data[i],
156 ib->page_order);
157 }
158 kfree(ib);
159 return ERR_PTR(-ENOMEM);
160 }
161 return ib;
162}
163
164/*
165 * Free an idal buffer.
166 */
167static inline void
168idal_buffer_free(struct idal_buffer *ib)
169{
170 int nr_chunks, nr_ptrs, i;
171
172 nr_ptrs = (ib->size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
173 nr_chunks = (4096 << ib->page_order) >> IDA_SIZE_LOG;
174 for (i = 0; i < nr_ptrs; i += nr_chunks)
175 free_pages((unsigned long) ib->data[i], ib->page_order);
176 kfree(ib);
177}
178
179/*
180 * Test if a idal list is really needed.
181 */
182static inline int
183__idal_buffer_is_needed(struct idal_buffer *ib)
184{
185#ifdef __s390x__
186 return ib->size > (4096ul << ib->page_order) ||
187 idal_is_needed(ib->data[0], ib->size);
188#else
189 return ib->size > (4096ul << ib->page_order);
190#endif
191}
192
193/*
194 * Set channel data address to idal buffer.
195 */
196static inline void
197idal_buffer_set_cda(struct idal_buffer *ib, struct ccw1 *ccw)
198{
199 if (__idal_buffer_is_needed(ib)) {
200 // setup idals;
201 ccw->cda = (u32)(addr_t) ib->data;
202 ccw->flags |= CCW_FLAG_IDA;
203 } else
204 // we do not need idals - use direct addressing
205 ccw->cda = (u32)(addr_t) ib->data[0];
206 ccw->count = ib->size;
207}
208
209/*
210 * Copy count bytes from an idal buffer to user memory
211 */
212static inline size_t
213idal_buffer_to_user(struct idal_buffer *ib, void __user *to, size_t count)
214{
215 size_t left;
216 int i;
217
218 BUG_ON(count > ib->size);
219 for (i = 0; count > IDA_BLOCK_SIZE; i++) {
220 left = copy_to_user(to, ib->data[i], IDA_BLOCK_SIZE);
221 if (left)
222 return left + count - IDA_BLOCK_SIZE;
223 to = (void __user *) to + IDA_BLOCK_SIZE;
224 count -= IDA_BLOCK_SIZE;
225 }
226 return copy_to_user(to, ib->data[i], count);
227}
228
229/*
230 * Copy count bytes from user memory to an idal buffer
231 */
232static inline size_t
233idal_buffer_from_user(struct idal_buffer *ib, const void __user *from, size_t count)
234{
235 size_t left;
236 int i;
237
238 BUG_ON(count > ib->size);
239 for (i = 0; count > IDA_BLOCK_SIZE; i++) {
240 left = copy_from_user(ib->data[i], from, IDA_BLOCK_SIZE);
241 if (left)
242 return left + count - IDA_BLOCK_SIZE;
243 from = (void __user *) from + IDA_BLOCK_SIZE;
244 count -= IDA_BLOCK_SIZE;
245 }
246 return copy_from_user(ib->data[i], from, count);
247}
248
249#endif