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
  19 typedef struct ScatterGatherEntry ScatterGatherEntry;
  20
  21 typedef enum {
  22     DMA_DIRECTION_TO_DEVICE = 0,
  23     DMA_DIRECTION_FROM_DEVICE = 1,
  24 } DMADirection;
  25
  26 struct QEMUSGList {
  27     ScatterGatherEntry *sg;
  28     int nsg;
  29     int nalloc;
  30     size_t size;
  31     DeviceState *dev;
  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     smp_mb();
  70 }
  71
  72 /* Checks that the given range of addresses is valid for DMA.  This is
  73  * useful for certain cases, but usually you should just use
  74  * dma_memory_{read,write}() and check for errors */
  75 static inline bool dma_memory_valid(AddressSpace *as,
  76                                     dma_addr_t addr, dma_addr_t len,
  77                                     DMADirection dir)
  78 {
  79     return address_space_access_valid(as, addr, len,
  80                                       dir == DMA_DIRECTION_FROM_DEVICE);
  81 }
  82
  83 static inline int dma_memory_rw_relaxed(AddressSpace *as, dma_addr_t addr,
  84                                         void *buf, dma_addr_t len,
  85                                         DMADirection dir)
  86 {
  87     return (bool)address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED,
  88                                   buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
  89 }
  90
  91 static inline int dma_memory_read_relaxed(AddressSpace *as, dma_addr_t addr,
  92                                           void *buf, dma_addr_t len)
  93 {
  94     return dma_memory_rw_relaxed(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
  95 }
  96
  97 static inline int dma_memory_write_relaxed(AddressSpace *as, dma_addr_t addr,
  98                                            const void *buf, dma_addr_t len)
  99 {
 100     return dma_memory_rw_relaxed(as, addr, (void *)buf, len,
 101                                  DMA_DIRECTION_FROM_DEVICE);
 102 }
 103
 104 static inline int dma_memory_rw(AddressSpace *as, dma_addr_t addr,
 105                                 void *buf, dma_addr_t len,
 106                                 DMADirection dir)
 107 {
 108     dma_barrier(as, dir);
 109
 110     return dma_memory_rw_relaxed(as, addr, buf, len, dir);
 111 }
 112
 113 static inline int dma_memory_read(AddressSpace *as, dma_addr_t addr,
 114                                   void *buf, dma_addr_t len)
 115 {
 116     return dma_memory_rw(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
 117 }
 118
 119 static inline int dma_memory_write(AddressSpace *as, dma_addr_t addr,
 120                                    const void *buf, dma_addr_t len)
 121 {
 122     return dma_memory_rw(as, addr, (void *)buf, len,
 123                          DMA_DIRECTION_FROM_DEVICE);
 124 }
 125
 126 int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len);
 127
 128 static inline void *dma_memory_map(AddressSpace *as,
 129                                    dma_addr_t addr, dma_addr_t *len,
 130                                    DMADirection dir)
 131 {
 132     hwaddr xlen = *len;
 133     void *p;
 134
 135     p = address_space_map(as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);
 136     *len = xlen;
 137     return p;
 138 }
 139
 140 static inline void dma_memory_unmap(AddressSpace *as,
 141                                     void *buffer, dma_addr_t len,
 142                                     DMADirection dir, dma_addr_t access_len)
 143 {
 144     address_space_unmap(as, buffer, (hwaddr)len,
 145                         dir == DMA_DIRECTION_FROM_DEVICE, access_len);
 146 }
 147
 148 #define DEFINE_LDST_DMA(_lname, _sname, _bits, _end) \
 149     static inline uint##_bits##_t ld##_lname##_##_end##_dma(AddressSpace *as, \
 150                                                             dma_addr_t addr) \
 151     {                                                                   \
 152         uint##_bits##_t val;                                            \
 153         dma_memory_read(as, addr, &val, (_bits) / 8);                   \
 154         return _end##_bits##_to_cpu(val);                               \
 155     }                                                                   \
 156     static inline void st##_sname##_##_end##_dma(AddressSpace *as,      \
 157                                                  dma_addr_t addr,       \
 158                                                  uint##_bits##_t val)   \
 159     {                                                                   \
 160         val = cpu_to_##_end##_bits(val);                                \
 161         dma_memory_write(as, addr, &val, (_bits) / 8);                  \
 162     }
 163
 164 static inline uint8_t ldub_dma(AddressSpace *as, dma_addr_t addr)
 165 {
 166     uint8_t val;
 167
 168     dma_memory_read(as, addr, &val, 1);
 169     return val;
 170 }
 171
 172 static inline void stb_dma(AddressSpace *as, dma_addr_t addr, uint8_t val)
 173 {
 174     dma_memory_write(as, addr, &val, 1);
 175 }
 176
 177 DEFINE_LDST_DMA(uw, w, 16, le);
 178 DEFINE_LDST_DMA(l, l, 32, le);
 179 DEFINE_LDST_DMA(q, q, 64, le);
 180 DEFINE_LDST_DMA(uw, w, 16, be);
 181 DEFINE_LDST_DMA(l, l, 32, be);
 182 DEFINE_LDST_DMA(q, q, 64, be);
 183
 184 #undef DEFINE_LDST_DMA
 185
 186 struct ScatterGatherEntry {
 187     dma_addr_t base;
 188     dma_addr_t len;
 189 };
 190
 191 void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
 192                       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 BlockAIOCB *DMAIOFunc(int64_t offset, QEMUIOVector *iov,
 198                               BlockCompletionFunc *cb, void *cb_opaque,
 199                               void *opaque);
 200
 201 BlockAIOCB *dma_blk_io(AioContext *ctx,
 202                        QEMUSGList *sg, uint64_t offset, uint32_t align,
 203                        DMAIOFunc *io_func, void *io_func_opaque,
 204                        BlockCompletionFunc *cb, void *opaque, DMADirection dir);
 205 BlockAIOCB *dma_blk_read(BlockBackend *blk,
 206                          QEMUSGList *sg, uint64_t offset, uint32_t align,
 207                          BlockCompletionFunc *cb, void *opaque);
 208 BlockAIOCB *dma_blk_write(BlockBackend *blk,
 209                           QEMUSGList *sg, uint64_t offset, uint32_t align,
 210                           BlockCompletionFunc *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(BlockBackend *blk, BlockAcctCookie *cookie,
 215                     QEMUSGList *sg, enum BlockAcctType type);
 216
 217 #endif