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