summaryrefslogtreecommitdiff
path: root/dma.h
blob: acacf1bf27d216de319bf14fa2c48ed98116cf07 (plain)
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
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
/*
 * DMA helper functions
 *
 * Copyright (c) 2009 Red Hat
 *
 * This work is licensed under the terms of the GNU General Public License
 * (GNU GPL), version 2 or later.
 */

#ifndef DMA_H
#define DMA_H

#include <stdio.h>
#include "hw/hw.h"
#include "block.h"
#include "kvm.h"

typedef struct DMAContext DMAContext;
typedef struct ScatterGatherEntry ScatterGatherEntry;

typedef enum {
    DMA_DIRECTION_TO_DEVICE = 0,
    DMA_DIRECTION_FROM_DEVICE = 1,
} DMADirection;

struct QEMUSGList {
    ScatterGatherEntry *sg;
    int nsg;
    int nalloc;
    size_t size;
    DMAContext *dma;
};

#if defined(TARGET_PHYS_ADDR_BITS)

/*
 * When an IOMMU is present, bus addresses become distinct from
 * CPU/memory physical addresses and may be a different size.  Because
 * the IOVA size depends more on the bus than on the platform, we more
 * or less have to treat these as 64-bit always to cover all (or at
 * least most) cases.
 */
typedef uint64_t dma_addr_t;

#define DMA_ADDR_BITS 64
#define DMA_ADDR_FMT "%" PRIx64

typedef int DMATranslateFunc(DMAContext *dma,
                             dma_addr_t addr,
                             target_phys_addr_t *paddr,
                             target_phys_addr_t *len,
                             DMADirection dir);
typedef void* DMAMapFunc(DMAContext *dma,
                         dma_addr_t addr,
                         dma_addr_t *len,
                         DMADirection dir);
typedef void DMAUnmapFunc(DMAContext *dma,
                          void *buffer,
                          dma_addr_t len,
                          DMADirection dir,
                          dma_addr_t access_len);

struct DMAContext {
    DMATranslateFunc *translate;
    DMAMapFunc *map;
    DMAUnmapFunc *unmap;
};

static inline void dma_barrier(DMAContext *dma, DMADirection dir)
{
    /*
     * This is called before DMA read and write operations
     * unless the _relaxed form is used and is responsible
     * for providing some sane ordering of accesses vs
     * concurrently running VCPUs.
     *
     * Users of map(), unmap() or lower level st/ld_*
     * operations are responsible for providing their own
     * ordering via barriers.
     *
     * This primitive implementation does a simple smp_mb()
     * before each operation which provides pretty much full
     * ordering.
     *
     * A smarter implementation can be devised if needed to
     * use lighter barriers based on the direction of the
     * transfer, the DMA context, etc...
     */
    if (kvm_enabled()) {
        smp_mb();
    }
}

static inline bool dma_has_iommu(DMAContext *dma)
{
    return !!dma;
}

/* Checks that the given range of addresses is valid for DMA.  This is
 * useful for certain cases, but usually you should just use
 * dma_memory_{read,write}() and check for errors */
bool iommu_dma_memory_valid(DMAContext *dma, dma_addr_t addr, dma_addr_t len,
                            DMADirection dir);
static inline bool dma_memory_valid(DMAContext *dma,
                                    dma_addr_t addr, dma_addr_t len,
                                    DMADirection dir)
{
    if (!dma_has_iommu(dma)) {
        return true;
    } else {
        return iommu_dma_memory_valid(dma, addr, len, dir);
    }
}

int iommu_dma_memory_rw(DMAContext *dma, dma_addr_t addr,
                        void *buf, dma_addr_t len, DMADirection dir);
static inline int dma_memory_rw_relaxed(DMAContext *dma, dma_addr_t addr,
                                        void *buf, dma_addr_t len,
                                        DMADirection dir)
{
    if (!dma_has_iommu(dma)) {
        /* Fast-path for no IOMMU */
        cpu_physical_memory_rw(addr, buf, len,
                               dir == DMA_DIRECTION_FROM_DEVICE);
        return 0;
    } else {
        return iommu_dma_memory_rw(dma, addr, buf, len, dir);
    }
}

static inline int dma_memory_read_relaxed(DMAContext *dma, dma_addr_t addr,
                                          void *buf, dma_addr_t len)
{
    return dma_memory_rw_relaxed(dma, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
}

static inline int dma_memory_write_relaxed(DMAContext *dma, dma_addr_t addr,
                                           const void *buf, dma_addr_t len)
{
    return dma_memory_rw_relaxed(dma, addr, (void *)buf, len,
                                 DMA_DIRECTION_FROM_DEVICE);
}

static inline int dma_memory_rw(DMAContext *dma, dma_addr_t addr,
                                void *buf, dma_addr_t len,
                                DMADirection dir)
{
    dma_barrier(dma, dir);

    return dma_memory_rw_relaxed(dma, addr, buf, len, dir);
}

static inline int dma_memory_read(DMAContext *dma, dma_addr_t addr,
                                  void *buf, dma_addr_t len)
{
    return dma_memory_rw(dma, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
}

static inline int dma_memory_write(DMAContext *dma, dma_addr_t addr,
                                   const void *buf, dma_addr_t len)
{
    return dma_memory_rw(dma, addr, (void *)buf, len,
                         DMA_DIRECTION_FROM_DEVICE);
}

int iommu_dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c,
			 dma_addr_t len);

int dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c, dma_addr_t len);

void *iommu_dma_memory_map(DMAContext *dma,
                           dma_addr_t addr, dma_addr_t *len,
                           DMADirection dir);
static inline void *dma_memory_map(DMAContext *dma,
                                   dma_addr_t addr, dma_addr_t *len,
                                   DMADirection dir)
{
    if (!dma_has_iommu(dma)) {
        target_phys_addr_t xlen = *len;
        void *p;

        p = cpu_physical_memory_map(addr, &xlen,
                                    dir == DMA_DIRECTION_FROM_DEVICE);
        *len = xlen;
        return p;
    } else {
        return iommu_dma_memory_map(dma, addr, len, dir);
    }
}

void iommu_dma_memory_unmap(DMAContext *dma,
                            void *buffer, dma_addr_t len,
                            DMADirection dir, dma_addr_t access_len);
static inline void dma_memory_unmap(DMAContext *dma,
                                    void *buffer, dma_addr_t len,
                                    DMADirection dir, dma_addr_t access_len)
{
    if (!dma_has_iommu(dma)) {
        return cpu_physical_memory_unmap(buffer, (target_phys_addr_t)len,
                                         dir == DMA_DIRECTION_FROM_DEVICE,
                                         access_len);
    } else {
        iommu_dma_memory_unmap(dma, buffer, len, dir, access_len);
    }
}

#define DEFINE_LDST_DMA(_lname, _sname, _bits, _end) \
    static inline uint##_bits##_t ld##_lname##_##_end##_dma(DMAContext *dma, \
                                                            dma_addr_t addr) \
    {                                                                   \
        uint##_bits##_t val;                                            \
        dma_memory_read(dma, addr, &val, (_bits) / 8);                  \
        return _end##_bits##_to_cpu(val);                               \
    }                                                                   \
    static inline void st##_sname##_##_end##_dma(DMAContext *dma,       \
                                                 dma_addr_t addr,       \
                                                 uint##_bits##_t val)   \
    {                                                                   \
        val = cpu_to_##_end##_bits(val);                                \
        dma_memory_write(dma, addr, &val, (_bits) / 8);                 \
    }

static inline uint8_t ldub_dma(DMAContext *dma, dma_addr_t addr)
{
    uint8_t val;

    dma_memory_read(dma, addr, &val, 1);
    return val;
}

static inline void stb_dma(DMAContext *dma, dma_addr_t addr, uint8_t val)
{
    dma_memory_write(dma, addr, &val, 1);
}

DEFINE_LDST_DMA(uw, w, 16, le);
DEFINE_LDST_DMA(l, l, 32, le);
DEFINE_LDST_DMA(q, q, 64, le);
DEFINE_LDST_DMA(uw, w, 16, be);
DEFINE_LDST_DMA(l, l, 32, be);
DEFINE_LDST_DMA(q, q, 64, be);

#undef DEFINE_LDST_DMA

void dma_context_init(DMAContext *dma, DMATranslateFunc translate,
                      DMAMapFunc map, DMAUnmapFunc unmap);

struct ScatterGatherEntry {
    dma_addr_t base;
    dma_addr_t len;
};

void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint, DMAContext *dma);
void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len);
void qemu_sglist_destroy(QEMUSGList *qsg);
#endif

typedef BlockDriverAIOCB *DMAIOFunc(BlockDriverState *bs, int64_t sector_num,
                                 QEMUIOVector *iov, int nb_sectors,
                                 BlockDriverCompletionFunc *cb, void *opaque);

BlockDriverAIOCB *dma_bdrv_io(BlockDriverState *bs,
                              QEMUSGList *sg, uint64_t sector_num,
                              DMAIOFunc *io_func, BlockDriverCompletionFunc *cb,
                              void *opaque, DMADirection dir);
BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs,
                                QEMUSGList *sg, uint64_t sector,
                                BlockDriverCompletionFunc *cb, void *opaque);
BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs,
                                 QEMUSGList *sg, uint64_t sector,
                                 BlockDriverCompletionFunc *cb, void *opaque);
uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg);
uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg);

void dma_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie,
                    QEMUSGList *sg, enum BlockAcctType type);

#endif