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 "block/accounting.h"
  19 #include "sysemu/kvm.h"
  20
  21 typedef struct ScatterGatherEntry ScatterGatherEntry;
  22
  23 typedef enum {
  24     DMA_DIRECTION_TO_DEVICE = 0,
  25     DMA_DIRECTION_FROM_DEVICE = 1,
  26 } DMADirection;
  27
  28 struct QEMUSGList {
  29     ScatterGatherEntry *sg;
  30     int nsg;
  31     int nalloc;
  32     size_t size;
  33     DeviceState *dev;
  34     AddressSpace *as;
  35 };
  36
  37 #ifndef CONFIG_USER_ONLY
  38
  39 /*
  40  * When an IOMMU is present, bus addresses become distinct from
  41  * CPU/memory physical addresses and may be a different size.  Because
  42  * the IOVA size depends more on the bus than on the platform, we more
  43  * or less have to treat these as 64-bit always to cover all (or at
  44  * least most) cases.
  45  */
  46 typedef uint64_t dma_addr_t;
  47
  48 #define DMA_ADDR_BITS 64
  49 #define DMA_ADDR_FMT "%" PRIx64
  50
  51 static inline void dma_barrier(AddressSpace *as, DMADirection dir)
  52 {
  53     /*
  54      * This is called before DMA read and write operations
  55      * unless the _relaxed form is used and is responsible
  56      * for providing some sane ordering of accesses vs
  57      * concurrently running VCPUs.
  58      *
  59      * Users of map(), unmap() or lower level st/ld_*
  60      * operations are responsible for providing their own
  61      * ordering via barriers.
  62      *
  63      * This primitive implementation does a simple smp_mb()
  64      * before each operation which provides pretty much full
  65      * ordering.
  66      *
  67      * A smarter implementation can be devised if needed to
  68      * use lighter barriers based on the direction of the
  69      * transfer, the DMA context, etc...
  70      */
  71     if (kvm_enabled()) {
  72         smp_mb();
  73     }
  74 }
  75
  76 /* Checks that the given range of addresses is valid for DMA.  This is
  77  * useful for certain cases, but usually you should just use
  78  * dma_memory_{read,write}() and check for errors */
  79 static inline bool dma_memory_valid(AddressSpace *as,
  80                                     dma_addr_t addr, dma_addr_t len,
  81                                     DMADirection dir)
  82 {
  83     return address_space_access_valid(as, addr, len,
  84                                       dir == DMA_DIRECTION_FROM_DEVICE);
  85 }
  86
  87 static inline int dma_memory_rw_relaxed(AddressSpace *as, dma_addr_t addr,
  88                                         void *buf, dma_addr_t len,
  89                                         DMADirection dir)
  90 {
  91     return (bool)address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED,
  92                                   buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
  93 }
  94
  95 static inline int dma_memory_read_relaxed(AddressSpace *as, dma_addr_t addr,
  96                                           void *buf, dma_addr_t len)
  97 {
  98     return dma_memory_rw_relaxed(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
  99 }
 100
 101 static inline int dma_memory_write_relaxed(AddressSpace *as, dma_addr_t addr,
 102                                            const void *buf, dma_addr_t len)
 103 {
 104     return dma_memory_rw_relaxed(as, addr, (void *)buf, len,
 105                                  DMA_DIRECTION_FROM_DEVICE);
 106 }
 107
 108 static inline int dma_memory_rw(AddressSpace *as, dma_addr_t addr,
 109                                 void *buf, dma_addr_t len,
 110                                 DMADirection dir)
 111 {
 112     dma_barrier(as, dir);
 113
 114     return dma_memory_rw_relaxed(as, addr, buf, len, dir);
 115 }
 116
 117 static inline int dma_memory_read(AddressSpace *as, dma_addr_t addr,
 118                                   void *buf, dma_addr_t len)
 119 {
 120     return dma_memory_rw(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
 121 }
 122
 123 static inline int dma_memory_write(AddressSpace *as, dma_addr_t addr,
 124                                    const void *buf, dma_addr_t len)
 125 {
 126     return dma_memory_rw(as, addr, (void *)buf, len,
 127                          DMA_DIRECTION_FROM_DEVICE);
 128 }
 129
 130 int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len);
 131
 132 static inline void *dma_memory_map(AddressSpace *as,
 133                                    dma_addr_t addr, dma_addr_t *len,
 134                                    DMADirection dir)
 135 {
 136     hwaddr xlen = *len;
 137     void *p;
 138
 139     p = address_space_map(as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);
 140     *len = xlen;
 141     return p;
 142 }
 143
 144 static inline void dma_memory_unmap(AddressSpace *as,
 145                                     void *buffer, dma_addr_t len,
 146                                     DMADirection dir, dma_addr_t access_len)
 147 {
 148     address_space_unmap(as, buffer, (hwaddr)len,
 149                         dir == DMA_DIRECTION_FROM_DEVICE, access_len);
 150 }
 151
 152 #define DEFINE_LDST_DMA(_lname, _sname, _bits, _end) \
 153     static inline uint##_bits##_t ld##_lname##_##_end##_dma(AddressSpace *as, \
 154                                                             dma_addr_t addr) \
 155     {                                                                   \
 156         uint##_bits##_t val;                                            \
 157         dma_memory_read(as, addr, &val, (_bits) / 8);                   \
 158         return _end##_bits##_to_cpu(val);                               \
 159     }                                                                   \
 160     static inline void st##_sname##_##_end##_dma(AddressSpace *as,      \
 161                                                  dma_addr_t addr,       \
 162                                                  uint##_bits##_t val)   \
 163     {                                                                   \
 164         val = cpu_to_##_end##_bits(val);                                \
 165         dma_memory_write(as, addr, &val, (_bits) / 8);                  \
 166     }
 167
 168 static inline uint8_t ldub_dma(AddressSpace *as, dma_addr_t addr)
 169 {
 170     uint8_t val;
 171
 172     dma_memory_read(as, addr, &val, 1);
 173     return val;
 174 }
 175
 176 static inline void stb_dma(AddressSpace *as, dma_addr_t addr, uint8_t val)
 177 {
 178     dma_memory_write(as, addr, &val, 1);
 179 }
 180
 181 DEFINE_LDST_DMA(uw, w, 16, le);
 182 DEFINE_LDST_DMA(l, l, 32, le);
 183 DEFINE_LDST_DMA(q, q, 64, le);
 184 DEFINE_LDST_DMA(uw, w, 16, be);
 185 DEFINE_LDST_DMA(l, l, 32, be);
 186 DEFINE_LDST_DMA(q, q, 64, be);
 187
 188 #undef DEFINE_LDST_DMA
 189
 190 struct ScatterGatherEntry {
 191     dma_addr_t base;
 192     dma_addr_t len;
 193 };
 194
 195 void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
 196                       AddressSpace *as);
 197 void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len);
 198 void qemu_sglist_destroy(QEMUSGList *qsg);
 199 #endif
 200
 201 typedef BlockAIOCB *DMAIOFunc(BlockBackend *blk, int64_t sector_num,
 202                               QEMUIOVector *iov, int nb_sectors,
 203                               BlockCompletionFunc *cb, void *opaque);
 204
 205 BlockAIOCB *dma_blk_io(BlockBackend *blk,
 206                        QEMUSGList *sg, uint64_t sector_num,
 207                        DMAIOFunc *io_func, BlockCompletionFunc *cb,
 208                        void *opaque, DMADirection dir);
 209 BlockAIOCB *dma_blk_read(BlockBackend *blk,
 210                          QEMUSGList *sg, uint64_t sector,
 211                          BlockCompletionFunc *cb, void *opaque);
 212 BlockAIOCB *dma_blk_write(BlockBackend *blk,
 213                           QEMUSGList *sg, uint64_t sector,
 214                           BlockCompletionFunc *cb, void *opaque);
 215 uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg);
 216 uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg);
 217
 218 void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie,
 219                     QEMUSGList *sg, enum BlockAcctType type);
 220
 221 #endif