include/sysemu/dma.h

   1 /*
   2  * DMA helper functions
   3  *
   4  * Copyright (c) 2009 Red Hat
   5  *
   6  * This work is licensed under the terms of the GNU General Public License
   7  * (GNU GPL), version 2 or later.
   8  */
   9
  10 #ifndef DMA_H
  11 #define DMA_H
  12
  13 #include <stdio.h>
  14 #include "exec/memory.h"
  15 #include "exec/address-spaces.h"
  16 #include "hw/hw.h"
  17 #include "block/block.h"
  18 #include "sysemu/kvm.h"
  19
  20 typedef struct ScatterGatherEntry ScatterGatherEntry;
  21
  22 typedef enum {
  23     DMA_DIRECTION_TO_DEVICE = 0,
  24     DMA_DIRECTION_FROM_DEVICE = 1,
  25 } DMADirection;
  26
  27 struct QEMUSGList {
  28     ScatterGatherEntry *sg;
  29     int nsg;
  30     int nalloc;
  31     size_t size;
  32     DeviceState *dev;
  33     AddressSpace *as;
  34 };
  35
  36 #ifndef CONFIG_USER_ONLY
  37
  38 /*
  39  * When an IOMMU is present, bus addresses become distinct from
  40  * CPU/memory physical addresses and may be a different size.  Because
  41  * the IOVA size depends more on the bus than on the platform, we more
  42  * or less have to treat these as 64-bit always to cover all (or at
  43  * least most) cases.
  44  */
  45 typedef uint64_t dma_addr_t;
  46
  47 #define DMA_ADDR_BITS 64
  48 #define DMA_ADDR_FMT "%" PRIx64
  49
  50 static inline void dma_barrier(AddressSpace *as, DMADirection dir)
  51 {
  52     /*
  53      * This is called before DMA read and write operations
  54      * unless the _relaxed form is used and is responsible
  55      * for providing some sane ordering of accesses vs
  56      * concurrently running VCPUs.
  57      *
  58      * Users of map(), unmap() or lower level st/ld_*
  59      * operations are responsible for providing their own
  60      * ordering via barriers.
  61      *
  62      * This primitive implementation does a simple smp_mb()
  63      * before each operation which provides pretty much full
  64      * ordering.
  65      *
  66      * A smarter implementation can be devised if needed to
  67      * use lighter barriers based on the direction of the
  68      * transfer, the DMA context, etc...
  69      */
  70     if (kvm_enabled()) {
  71         smp_mb();
  72     }
  73 }
  74
  75 /* Checks that the given range of addresses is valid for DMA.  This is
  76  * useful for certain cases, but usually you should just use
  77  * dma_memory_{read,write}() and check for errors */
  78 static inline bool dma_memory_valid(AddressSpace *as,
  79                                     dma_addr_t addr, dma_addr_t len,
  80                                     DMADirection dir)
  81 {
  82     return address_space_access_valid(as, addr, len,
  83                                       dir == DMA_DIRECTION_FROM_DEVICE);
  84 }
  85
  86 static inline int dma_memory_rw_relaxed(AddressSpace *as, dma_addr_t addr,
  87                                         void *buf, dma_addr_t len,
  88                                         DMADirection dir)
  89 {
  90     return address_space_rw(as, addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
  91 }
  92
  93 static inline int dma_memory_read_relaxed(AddressSpace *as, dma_addr_t addr,
  94                                           void *buf, dma_addr_t len)
  95 {
  96     return dma_memory_rw_relaxed(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
  97 }
  98
  99 static inline int dma_memory_write_relaxed(AddressSpace *as, dma_addr_t addr,
 100                                            const void *buf, dma_addr_t len)
 101 {
 102     return dma_memory_rw_relaxed(as, addr, (void *)buf, len,
 103                                  DMA_DIRECTION_FROM_DEVICE);
 104 }
 105
 106 static inline int dma_memory_rw(AddressSpace *as, dma_addr_t addr,
 107                                 void *buf, dma_addr_t len,
 108                                 DMADirection dir)
 109 {
 110     dma_barrier(as, dir);
 111
 112     return dma_memory_rw_relaxed(as, addr, buf, len, dir);
 113 }
 114
 115 static inline int dma_memory_read(AddressSpace *as, dma_addr_t addr,
 116                                   void *buf, dma_addr_t len)
 117 {
 118     return dma_memory_rw(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
 119 }
 120
 121 static inline int dma_memory_write(AddressSpace *as, dma_addr_t addr,
 122                                    const void *buf, dma_addr_t len)
 123 {
 124     return dma_memory_rw(as, addr, (void *)buf, len,
 125                          DMA_DIRECTION_FROM_DEVICE);
 126 }
 127
 128 int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len);
 129
 130 static inline void *dma_memory_map(AddressSpace *as,
 131                                    dma_addr_t addr, dma_addr_t *len,
 132                                    DMADirection dir)
 133 {
 134     hwaddr xlen = *len;
 135     void *p;
 136
 137     p = address_space_map(as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);
 138     *len = xlen;
 139     return p;
 140 }
 141
 142 static inline void dma_memory_unmap(AddressSpace *as,
 143                                     void *buffer, dma_addr_t len,
 144                                     DMADirection dir, dma_addr_t access_len)
 145 {
 146     address_space_unmap(as, buffer, (hwaddr)len,
 147                         dir == DMA_DIRECTION_FROM_DEVICE, access_len);
 148 }
 149
 150 #define DEFINE_LDST_DMA(_lname, _sname, _bits, _end) \
 151     static inline uint##_bits##_t ld##_lname##_##_end##_dma(AddressSpace *as, \
 152                                                             dma_addr_t addr) \
 153     {                                                                   \
 154         uint##_bits##_t val;                                            \
 155         dma_memory_read(as, addr, &val, (_bits) / 8);                   \
 156         return _end##_bits##_to_cpu(val);                               \
 157     }                                                                   \
 158     static inline void st##_sname##_##_end##_dma(AddressSpace *as,      \
 159                                                  dma_addr_t addr,       \
 160                                                  uint##_bits##_t val)   \
 161     {                                                                   \
 162         val = cpu_to_##_end##_bits(val);                                \
 163         dma_memory_write(as, addr, &val, (_bits) / 8);                  \
 164     }
 165
 166 static inline uint8_t ldub_dma(AddressSpace *as, dma_addr_t addr)
 167 {
 168     uint8_t val;
 169
 170     dma_memory_read(as, addr, &val, 1);
 171     return val;
 172 }
 173
 174 static inline void stb_dma(AddressSpace *as, dma_addr_t addr, uint8_t val)
 175 {
 176     dma_memory_write(as, addr, &val, 1);
 177 }
 178
 179 DEFINE_LDST_DMA(uw, w, 16, le);
 180 DEFINE_LDST_DMA(l, l, 32, le);
 181 DEFINE_LDST_DMA(q, q, 64, le);
 182 DEFINE_LDST_DMA(uw, w, 16, be);
 183 DEFINE_LDST_DMA(l, l, 32, be);
 184 DEFINE_LDST_DMA(q, q, 64, be);
 185
 186 #undef DEFINE_LDST_DMA
 187
 188 struct ScatterGatherEntry {
 189     dma_addr_t base;
 190     dma_addr_t len;
 191 };
 192
 193 void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
 194                       AddressSpace *as);
 195 void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len);
 196 void qemu_sglist_destroy(QEMUSGList *qsg);
 197 #endif
 198
 199 typedef BlockDriverAIOCB *DMAIOFunc(BlockDriverState *bs, int64_t sector_num,
 200                                  QEMUIOVector *iov, int nb_sectors,
 201                                  BlockDriverCompletionFunc *cb, void *opaque);
 202
 203 BlockDriverAIOCB *dma_bdrv_io(BlockDriverState *bs,
 204                               QEMUSGList *sg, uint64_t sector_num,
 205                               DMAIOFunc *io_func, BlockDriverCompletionFunc *cb,
 206                               void *opaque, DMADirection dir);
 207 BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs,
 208                                 QEMUSGList *sg, uint64_t sector,
 209                                 BlockDriverCompletionFunc *cb, void *opaque);
 210 BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs,
 211                                  QEMUSGList *sg, uint64_t sector,
 212                                  BlockDriverCompletionFunc *cb, void *opaque);
 213 uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg);
 214 uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg);
 215
 216 void dma_acct_start(BlockDriverState *bs, BlockAcctCookie *cookie,
 217                     QEMUSGList *sg, enum BlockAcctType type);
 218
 219 #endif