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 "exec/memory.h"
  14 #include "exec/address-spaces.h"
  15 #include "hw/hw.h"
  16 #include "block/block.h"
  17 #include "block/accounting.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 (bool)address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED,
  91                                   buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
  92 }
  93
  94 static inline int dma_memory_read_relaxed(AddressSpace *as, dma_addr_t addr,
  95                                           void *buf, dma_addr_t len)
  96 {
  97     return dma_memory_rw_relaxed(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
  98 }
  99
 100 static inline int dma_memory_write_relaxed(AddressSpace *as, dma_addr_t addr,
 101                                            const void *buf, dma_addr_t len)
 102 {
 103     return dma_memory_rw_relaxed(as, addr, (void *)buf, len,
 104                                  DMA_DIRECTION_FROM_DEVICE);
 105 }
 106
 107 static inline int dma_memory_rw(AddressSpace *as, dma_addr_t addr,
 108                                 void *buf, dma_addr_t len,
 109                                 DMADirection dir)
 110 {
 111     dma_barrier(as, dir);
 112
 113     return dma_memory_rw_relaxed(as, addr, buf, len, dir);
 114 }
 115
 116 static inline int dma_memory_read(AddressSpace *as, dma_addr_t addr,
 117                                   void *buf, dma_addr_t len)
 118 {
 119     return dma_memory_rw(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
 120 }
 121
 122 static inline int dma_memory_write(AddressSpace *as, dma_addr_t addr,
 123                                    const void *buf, dma_addr_t len)
 124 {
 125     return dma_memory_rw(as, addr, (void *)buf, len,
 126                          DMA_DIRECTION_FROM_DEVICE);
 127 }
 128
 129 int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len);
 130
 131 static inline void *dma_memory_map(AddressSpace *as,
 132                                    dma_addr_t addr, dma_addr_t *len,
 133                                    DMADirection dir)
 134 {
 135     hwaddr xlen = *len;
 136     void *p;
 137
 138     p = address_space_map(as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);
 139     *len = xlen;
 140     return p;
 141 }
 142
 143 static inline void dma_memory_unmap(AddressSpace *as,
 144                                     void *buffer, dma_addr_t len,
 145                                     DMADirection dir, dma_addr_t access_len)
 146 {
 147     address_space_unmap(as, buffer, (hwaddr)len,
 148                         dir == DMA_DIRECTION_FROM_DEVICE, access_len);
 149 }
 150
 151 #define DEFINE_LDST_DMA(_lname, _sname, _bits, _end) \
 152     static inline uint##_bits##_t ld##_lname##_##_end##_dma(AddressSpace *as, \
 153                                                             dma_addr_t addr) \
 154     {                                                                   \
 155         uint##_bits##_t val;                                            \
 156         dma_memory_read(as, addr, &val, (_bits) / 8);                   \
 157         return _end##_bits##_to_cpu(val);                               \
 158     }                                                                   \
 159     static inline void st##_sname##_##_end##_dma(AddressSpace *as,      \
 160                                                  dma_addr_t addr,       \
 161                                                  uint##_bits##_t val)   \
 162     {                                                                   \
 163         val = cpu_to_##_end##_bits(val);                                \
 164         dma_memory_write(as, addr, &val, (_bits) / 8);                  \
 165     }
 166
 167 static inline uint8_t ldub_dma(AddressSpace *as, dma_addr_t addr)
 168 {
 169     uint8_t val;
 170
 171     dma_memory_read(as, addr, &val, 1);
 172     return val;
 173 }
 174
 175 static inline void stb_dma(AddressSpace *as, dma_addr_t addr, uint8_t val)
 176 {
 177     dma_memory_write(as, addr, &val, 1);
 178 }
 179
 180 DEFINE_LDST_DMA(uw, w, 16, le);
 181 DEFINE_LDST_DMA(l, l, 32, le);
 182 DEFINE_LDST_DMA(q, q, 64, le);
 183 DEFINE_LDST_DMA(uw, w, 16, be);
 184 DEFINE_LDST_DMA(l, l, 32, be);
 185 DEFINE_LDST_DMA(q, q, 64, be);
 186
 187 #undef DEFINE_LDST_DMA
 188
 189 struct ScatterGatherEntry {
 190     dma_addr_t base;
 191     dma_addr_t len;
 192 };
 193
 194 void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
 195                       AddressSpace *as);
 196 void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len);
 197 void qemu_sglist_destroy(QEMUSGList *qsg);
 198 #endif
 199
 200 typedef BlockAIOCB *DMAIOFunc(BlockBackend *blk, int64_t sector_num,
 201                               QEMUIOVector *iov, int nb_sectors,
 202                               BlockCompletionFunc *cb, void *opaque);
 203
 204 BlockAIOCB *dma_blk_io(BlockBackend *blk,
 205                        QEMUSGList *sg, uint64_t sector_num,
 206                        DMAIOFunc *io_func, BlockCompletionFunc *cb,
 207                        void *opaque, DMADirection dir);
 208 BlockAIOCB *dma_blk_read(BlockBackend *blk,
 209                          QEMUSGList *sg, uint64_t sector,
 210                          BlockCompletionFunc *cb, void *opaque);
 211 BlockAIOCB *dma_blk_write(BlockBackend *blk,
 212                           QEMUSGList *sg, uint64_t sector,
 213                           BlockCompletionFunc *cb, void *opaque);
 214 uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg);
 215 uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg);
 216
 217 void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie,
 218                     QEMUSGList *sg, enum BlockAcctType type);
 219
 220 #endif