aboutsummaryrefslogtreecommitdiffstats
path: root/arch/s390/include/asm/idals.h
blob: e82c10efe65aee289c94fe59f761ce8c4c49acbb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
/* 
 * File...........: linux/include/asm-s390x/idals.h
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *		    Martin Schwidefsky <schwidefsky@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * (C) IBM Corporation, IBM Deutschland Entwicklung GmbH, 2000a
 
 * History of changes
 * 07/24/00 new file
 * 05/04/02 code restructuring.
 */

#ifndef _S390_IDALS_H
#define _S390_IDALS_H

#include <linux/errno.h>
#include <linux/err.h>
#include <linux/types.h>
#include <linux/slab.h>
#include <asm/cio.h>
#include <asm/uaccess.h>

#ifdef __s390x__
#define IDA_SIZE_LOG 12 /* 11 for 2k , 12 for 4k */
#else
#define IDA_SIZE_LOG 11 /* 11 for 2k , 12 for 4k */
#endif
#define IDA_BLOCK_SIZE (1L<<IDA_SIZE_LOG)

/*
 * Test if an address/length pair needs an idal list.
 */
static inline int
idal_is_needed(void *vaddr, unsigned int length)
{
#ifdef __s390x__
	return ((__pa(vaddr) + length - 1) >> 31) != 0;
#else
	return 0;
#endif
}


/*
 * Return the number of idal words needed for an address/length pair.
 */
static inline unsigned int
idal_nr_words(void *vaddr, unsigned int length)
{
#ifdef __s390x__
	if (idal_is_needed(vaddr, length))
		return ((__pa(vaddr) & (IDA_BLOCK_SIZE-1)) + length + 
			(IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
#endif
	return 0;
}

/*
 * Create the list of idal words for an address/length pair.
 */
static inline unsigned long *
idal_create_words(unsigned long *idaws, void *vaddr, unsigned int length)
{
#ifdef __s390x__
	unsigned long paddr;
	unsigned int cidaw;

	paddr = __pa(vaddr);
	cidaw = ((paddr & (IDA_BLOCK_SIZE-1)) + length + 
		 (IDA_BLOCK_SIZE-1)) >> IDA_SIZE_LOG;
	*idaws++ = paddr;
	paddr &= -IDA_BLOCK_SIZE;
	while (--cidaw > 0) {
		paddr += IDA_BLOCK_SIZE;
		*idaws++ = paddr;
	}
#endif
	return idaws;
}

/*
 * Sets the address of the data in CCW.
 * If necessary it allocates an IDAL and sets the appropriate flags.
 */
static inline int
set_normalized_cda(struct ccw1 * ccw, void *vaddr)
{
#ifdef __s390x__
	unsigned int nridaws;
	unsigned long *idal;

	if (ccw->flags & CCW_FLAG_IDA)
		return -EINVAL;
	nridaws = idal_nr_words(vaddr, ccw->count);
	if (nridaws > 0) {
		idal = kmalloc(nridaws * sizeof(unsigned long),
			       GFP_ATOMIC | GFP_DMA );
		if (idal == NULL)
			return -ENOMEM;
		idal_create_words(idal, vaddr, ccw->count);
		ccw->flags |= CCW_FLAG_IDA;
		vaddr = idal;
	}
#endif
	ccw->cda = (__u32)(unsigned long) vaddr;
	return 0;
}

/*
 * Releases any allocated IDAL related to the CCW.
 */
static inline void
clear_normalized_cda(struct ccw1 * ccw)
{
#ifdef __s390x__
	if (ccw->flags & CCW_FLAG_IDA) {
		kfree((void *)(unsigned long) ccw->cda);
		ccw->flags &= ~CCW_FLAG_IDA;
	}
#endif
	ccw->cda = 0;
}

/*
 * Idal buffer extension
 */
struct idal_buffer {
	size_t size;
	size_t page_order;
	void *data[0];
};

/*
 * Allocate an idal buffer
 */
static inline struct idal_buffer *
idal_buffer_alloc(size_t size, int page_order)
{
	struct idal_buffer *ib;
	int nr_chunks, nr_ptrs, i;

	nr_ptrs = (size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
	nr_chunks = (4096 << page_order) >> IDA_SIZE_LOG;
	ib = kmalloc(sizeof(struct idal_buffer) + nr_ptrs*sizeof(void *),
		     GFP_DMA | GFP_KERNEL);
	if (ib == NULL)
		return ERR_PTR(-ENOMEM);
	ib->size = size;
	ib->page_order = page_order;
	for (i = 0; i < nr_ptrs; i++) {
		if ((i & (nr_chunks - 1)) != 0) {
			ib->data[i] = ib->data[i-1] + IDA_BLOCK_SIZE;
			continue;
		}
		ib->data[i] = (void *)
			__get_free_pages(GFP_KERNEL, page_order);
		if (ib->data[i] != NULL)
			continue;
		// Not enough memory
		while (i >= nr_chunks) {
			i -= nr_chunks;
			free_pages((unsigned long) ib->data[i],
				   ib->page_order);
		}
		kfree(ib);
		return ERR_PTR(-ENOMEM);
	}
	return ib;
}

/*
 * Free an idal buffer.
 */
static inline void
idal_buffer_free(struct idal_buffer *ib)
{
	int nr_chunks, nr_ptrs, i;

	nr_ptrs = (ib->size + IDA_BLOCK_SIZE - 1) >> IDA_SIZE_LOG;
	nr_chunks = (4096 << ib->page_order) >> IDA_SIZE_LOG;
	for (i = 0; i < nr_ptrs; i += nr_chunks)
		free_pages((unsigned long) ib->data[i], ib->page_order);
	kfree(ib);
}

/*
 * Test if a idal list is really needed.
 */
static inline int
__idal_buffer_is_needed(struct idal_buffer *ib)
{
#ifdef __s390x__
	return ib->size > (4096ul << ib->page_order) ||
		idal_is_needed(ib->data[0], ib->size);
#else
	return ib->size > (4096ul << ib->page_order);
#endif
}

/*
 * Set channel data address to idal buffer.
 */
static inline void
idal_buffer_set_cda(struct idal_buffer *ib, struct ccw1 *ccw)
{
	if (__idal_buffer_is_needed(ib)) {
		// setup idals;
		ccw->cda = (u32)(addr_t) ib->data;
		ccw->flags |= CCW_FLAG_IDA;
	} else
		// we do not need idals - use direct addressing
		ccw->cda = (u32)(addr_t) ib->data[0];
	ccw->count = ib->size;
}

/*
 * Copy count bytes from an idal buffer to user memory
 */
static inline size_t
idal_buffer_to_user(struct idal_buffer *ib, void __user *to, size_t count)
{
	size_t left;
	int i;

	BUG_ON(count > ib->size);
	for (i = 0; count > IDA_BLOCK_SIZE; i++) {
		left = copy_to_user(to, ib->data[i], IDA_BLOCK_SIZE);
		if (left)
			return left + count - IDA_BLOCK_SIZE;
		to = (void __user *) to + IDA_BLOCK_SIZE;
		count -= IDA_BLOCK_SIZE;
	}
	return copy_to_user(to, ib->data[i], count);
}

/*
 * Copy count bytes from user memory to an idal buffer
 */
static inline size_t
idal_buffer_from_user(struct idal_buffer *ib, const void __user *from, size_t count)
{
	size_t left;
	int i;

	BUG_ON(count > ib->size);
	for (i = 0; count > IDA_BLOCK_SIZE; i++) {
		left = copy_from_user(ib->data[i], from, IDA_BLOCK_SIZE);
		if (left)
			return left + count - IDA_BLOCK_SIZE;
		from = (void __user *) from + IDA_BLOCK_SIZE;
		count -= IDA_BLOCK_SIZE;
	}
	return copy_from_user(ib->data[i], from, count);
}

#endif