qemu/include/sysemu/dma.h
Mark Cave-Ayland 99868af3d0 dma-helpers: explicitly pass alignment into DMA helpers
The hard-coded default alignment is BDRV_SECTOR_SIZE, however this is not
necessarily the case for all platforms. Use this as the default alignment for
all current callers.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Eric Blake <eblake@redhat.com>
Acked-by: John Snow <jsnow@redhat.com>
Message-id: 1476445266-27503-2-git-send-email-mark.cave-ayland@ilande.co.uk
Signed-off-by: John Snow <jsnow@redhat.com>
2016-10-27 16:29:13 -04:00

218 lines
7.4 KiB
C

/*
* DMA helper functions
*
* Copyright (c) 2009 Red Hat
*
* This work is licensed under the terms of the GNU General Public License
* (GNU GPL), version 2 or later.
*/
#ifndef DMA_H
#define DMA_H
#include "exec/memory.h"
#include "exec/address-spaces.h"
#include "hw/hw.h"
#include "block/block.h"
#include "block/accounting.h"
typedef struct ScatterGatherEntry ScatterGatherEntry;
typedef enum {
DMA_DIRECTION_TO_DEVICE = 0,
DMA_DIRECTION_FROM_DEVICE = 1,
} DMADirection;
struct QEMUSGList {
ScatterGatherEntry *sg;
int nsg;
int nalloc;
size_t size;
DeviceState *dev;
AddressSpace *as;
};
#ifndef CONFIG_USER_ONLY
/*
* When an IOMMU is present, bus addresses become distinct from
* CPU/memory physical addresses and may be a different size. Because
* the IOVA size depends more on the bus than on the platform, we more
* or less have to treat these as 64-bit always to cover all (or at
* least most) cases.
*/
typedef uint64_t dma_addr_t;
#define DMA_ADDR_BITS 64
#define DMA_ADDR_FMT "%" PRIx64
static inline void dma_barrier(AddressSpace *as, DMADirection dir)
{
/*
* This is called before DMA read and write operations
* unless the _relaxed form is used and is responsible
* for providing some sane ordering of accesses vs
* concurrently running VCPUs.
*
* Users of map(), unmap() or lower level st/ld_*
* operations are responsible for providing their own
* ordering via barriers.
*
* This primitive implementation does a simple smp_mb()
* before each operation which provides pretty much full
* ordering.
*
* A smarter implementation can be devised if needed to
* use lighter barriers based on the direction of the
* transfer, the DMA context, etc...
*/
smp_mb();
}
/* Checks that the given range of addresses is valid for DMA. This is
* useful for certain cases, but usually you should just use
* dma_memory_{read,write}() and check for errors */
static inline bool dma_memory_valid(AddressSpace *as,
dma_addr_t addr, dma_addr_t len,
DMADirection dir)
{
return address_space_access_valid(as, addr, len,
dir == DMA_DIRECTION_FROM_DEVICE);
}
static inline int dma_memory_rw_relaxed(AddressSpace *as, dma_addr_t addr,
void *buf, dma_addr_t len,
DMADirection dir)
{
return (bool)address_space_rw(as, addr, MEMTXATTRS_UNSPECIFIED,
buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
}
static inline int dma_memory_read_relaxed(AddressSpace *as, dma_addr_t addr,
void *buf, dma_addr_t len)
{
return dma_memory_rw_relaxed(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
}
static inline int dma_memory_write_relaxed(AddressSpace *as, dma_addr_t addr,
const void *buf, dma_addr_t len)
{
return dma_memory_rw_relaxed(as, addr, (void *)buf, len,
DMA_DIRECTION_FROM_DEVICE);
}
static inline int dma_memory_rw(AddressSpace *as, dma_addr_t addr,
void *buf, dma_addr_t len,
DMADirection dir)
{
dma_barrier(as, dir);
return dma_memory_rw_relaxed(as, addr, buf, len, dir);
}
static inline int dma_memory_read(AddressSpace *as, dma_addr_t addr,
void *buf, dma_addr_t len)
{
return dma_memory_rw(as, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
}
static inline int dma_memory_write(AddressSpace *as, dma_addr_t addr,
const void *buf, dma_addr_t len)
{
return dma_memory_rw(as, addr, (void *)buf, len,
DMA_DIRECTION_FROM_DEVICE);
}
int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len);
static inline void *dma_memory_map(AddressSpace *as,
dma_addr_t addr, dma_addr_t *len,
DMADirection dir)
{
hwaddr xlen = *len;
void *p;
p = address_space_map(as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);
*len = xlen;
return p;
}
static inline void dma_memory_unmap(AddressSpace *as,
void *buffer, dma_addr_t len,
DMADirection dir, dma_addr_t access_len)
{
address_space_unmap(as, buffer, (hwaddr)len,
dir == DMA_DIRECTION_FROM_DEVICE, access_len);
}
#define DEFINE_LDST_DMA(_lname, _sname, _bits, _end) \
static inline uint##_bits##_t ld##_lname##_##_end##_dma(AddressSpace *as, \
dma_addr_t addr) \
{ \
uint##_bits##_t val; \
dma_memory_read(as, addr, &val, (_bits) / 8); \
return _end##_bits##_to_cpu(val); \
} \
static inline void st##_sname##_##_end##_dma(AddressSpace *as, \
dma_addr_t addr, \
uint##_bits##_t val) \
{ \
val = cpu_to_##_end##_bits(val); \
dma_memory_write(as, addr, &val, (_bits) / 8); \
}
static inline uint8_t ldub_dma(AddressSpace *as, dma_addr_t addr)
{
uint8_t val;
dma_memory_read(as, addr, &val, 1);
return val;
}
static inline void stb_dma(AddressSpace *as, dma_addr_t addr, uint8_t val)
{
dma_memory_write(as, addr, &val, 1);
}
DEFINE_LDST_DMA(uw, w, 16, le);
DEFINE_LDST_DMA(l, l, 32, le);
DEFINE_LDST_DMA(q, q, 64, le);
DEFINE_LDST_DMA(uw, w, 16, be);
DEFINE_LDST_DMA(l, l, 32, be);
DEFINE_LDST_DMA(q, q, 64, be);
#undef DEFINE_LDST_DMA
struct ScatterGatherEntry {
dma_addr_t base;
dma_addr_t len;
};
void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
AddressSpace *as);
void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len);
void qemu_sglist_destroy(QEMUSGList *qsg);
#endif
typedef BlockAIOCB *DMAIOFunc(int64_t offset, QEMUIOVector *iov,
BlockCompletionFunc *cb, void *cb_opaque,
void *opaque);
BlockAIOCB *dma_blk_io(AioContext *ctx,
QEMUSGList *sg, uint64_t offset, uint32_t align,
DMAIOFunc *io_func, void *io_func_opaque,
BlockCompletionFunc *cb, void *opaque, DMADirection dir);
BlockAIOCB *dma_blk_read(BlockBackend *blk,
QEMUSGList *sg, uint64_t offset, uint32_t align,
BlockCompletionFunc *cb, void *opaque);
BlockAIOCB *dma_blk_write(BlockBackend *blk,
QEMUSGList *sg, uint64_t offset, uint32_t align,
BlockCompletionFunc *cb, void *opaque);
uint64_t dma_buf_read(uint8_t *ptr, int32_t len, QEMUSGList *sg);
uint64_t dma_buf_write(uint8_t *ptr, int32_t len, QEMUSGList *sg);
void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie,
QEMUSGList *sg, enum BlockAcctType type);
#endif