summaryrefslogtreecommitdiff
path: root/include/sysemu/dma.h
blob: b0fbb9bb352e8a55147f534e767a3fd03a3e31ce (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
/*
 * 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 "exec/memory.h"
#include "exec/address-spaces.h"
#include "hw/hw.h"
#include "block/block.h"
#include "block/accounting.h"
#include "sysemu/kvm.h"

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;
    DeviceState *dev;
    AddressSpace *as;
};

#ifndef CONFIG_USER_ONLY

/*
 * 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

static inline void dma_barrier(AddressSpace *as, 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();
    }
}

/* 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 */
static inline bool dma_memory_valid(AddressSpace *as,
                                    dma_addr_t addr, dma_addr_t len,
                                    DMADirection dir)
{
    return address_space_access_valid(as, addr, len,
                                      dir == DMA_DIRECTION_FROM_DEVICE);
}

static inline int dma_memory_rw_relaxed(AddressSpace *as, dma_addr_t addr,
                                        void *buf, dma_addr_t len,
                                        DMADirection dir)
{
    return (bool)address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED,
                                  buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
}

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

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

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

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

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

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

int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len);

static inline void *dma_memory_map(AddressSpace *as,
                                   dma_addr_t addr, dma_addr_t *len,
                                   DMADirection dir)
{
    hwaddr xlen = *len;
    void *p;

    p = address_space_map(as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);
    *len = xlen;
    return p;
}

static inline void dma_memory_unmap(AddressSpace *as,
                                    void *buffer, dma_addr_t len,
                                    DMADirection dir, dma_addr_t access_len)
{
    address_space_unmap(as, buffer, (hwaddr)len,
                        dir == DMA_DIRECTION_FROM_DEVICE, access_len);
}

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

static inline uint8_t ldub_dma(AddressSpace *as, dma_addr_t addr)
{
    uint8_t val;

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

static inline void stb_dma(AddressSpace *as, dma_addr_t addr, uint8_t val)
{
    dma_memory_write(as, 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

struct ScatterGatherEntry {
    dma_addr_t base;
    dma_addr_t len;
};

void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
                      AddressSpace *as);
void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len);
void qemu_sglist_destroy(QEMUSGList *qsg);
#endif

typedef BlockAIOCB *DMAIOFunc(BlockBackend *blk, int64_t sector_num,
                              QEMUIOVector *iov, int nb_sectors,
                              BlockCompletionFunc *cb, void *opaque);

BlockAIOCB *dma_blk_io(BlockBackend *blk,
                       QEMUSGList *sg, uint64_t sector_num,
                       DMAIOFunc *io_func, BlockCompletionFunc *cb,
                       void *opaque, DMADirection dir);
BlockAIOCB *dma_blk_read(BlockBackend *blk,
                         QEMUSGList *sg, uint64_t sector,
                         BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *dma_blk_write(BlockBackend *blk,
                          QEMUSGList *sg, uint64_t sector,
                          BlockCompletionFunc *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(BlockBackend *blk, BlockAcctCookie *cookie,
                    QEMUSGList *sg, enum BlockAcctType type);

#endif