/*
* 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 <stdio.h>
#include "hw/hw.h"
#include "block.h"
#include "kvm.h"
typedef struct DMAContext DMAContext;
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;
DMAContext *dma;
};
#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
typedef int DMATranslateFunc(DMAContext *dma,
dma_addr_t addr,
target_phys_addr_t *paddr,
target_phys_addr_t *len,
DMADirection dir);
typedef void* DMAMapFunc(DMAContext *dma,
dma_addr_t addr,
dma_addr_t *len,
DMADirection dir);
typedef void DMAUnmapFunc(DMAContext *dma,
void *buffer,
dma_addr_t len,
DMADirection dir,
dma_addr_t access_len);
struct DMAContext {
DMATranslateFunc *translate;
DMAMapFunc *map;
DMAUnmapFunc *unmap;
};
static inline void dma_barrier(DMAContext *dma, 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...
*/
if (kvm_enabled()) {
smp_mb();
}
}
static inline bool dma_has_iommu(DMAContext *dma)
{
return !!dma;
}
/* 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 */
bool iommu_dma_memory_valid(DMAContext *dma, dma_addr_t addr, dma_addr_t len,
DMADirection dir);
static inline bool dma_memory_valid(DMAContext *dma,
dma_addr_t addr, dma_addr_t len,
DMADirection dir)
{
if (!dma_has_iommu(dma)) {
return true;
} else {
return iommu_dma_memory_valid(dma, addr, len, dir);
}
}
int iommu_dma_memory_rw(DMAContext *dma, dma_addr_t addr,
void *buf, dma_addr_t len, DMADirection dir);
static inline int dma_memory_rw_relaxed(DMAContext *dma, dma_addr_t addr,
void *buf, dma_addr_t len,
DMADirection dir)
{
if (!dma_has_iommu(dma)) {
/* Fast-path for no IOMMU */
cpu_physical_memory_rw(addr, buf, len,
dir == DMA_DIRECTION_FROM_DEVICE);
return 0;
} else {
return iommu_dma_memory_rw(dma, addr, buf, len, dir);
}
}
static inline int dma_memory_read_relaxed(DMAContext *dma, dma_addr_t addr,
void *buf, dma_addr_t len)
{
return dma_memory_rw_relaxed(dma, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
}
static inline int dma_memory_write_relaxed(DMAContext *dma, dma_addr_t addr,
const void *buf, dma_addr_t len)
{
return dma_memory_rw_relaxed(dma, addr, (void *)buf, len,
DMA_DIRECTION_FROM_DEVICE);
}
static inline int dma_memory_rw(DMAContext *dma, dma_addr_t addr,
void *buf, dma_addr_t len,
DMADirection dir)
{
dma_barrier(dma, dir);
return dma_memory_rw_relaxed(dma, addr, buf, len, dir);
}
static inline int dma_memory_read(DMAContext *dma, dma_addr_t addr,
void *buf, dma_addr_t len)
{
return dma_memory_rw(dma, addr, buf, len, DMA_DIRECTION_TO_DEVICE);
}
static inline int dma_memory_write(DMAContext *dma, dma_addr_t addr,
const void *buf, dma_addr_t len)
{
return dma_memory_rw(dma, addr, (void *)buf, len,
DMA_DIRECTION_FROM_DEVICE);
}
int iommu_dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c,
dma_addr_t len);
int dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c, dma_addr_t len);
void *iommu_dma_memory_map(DMAContext *dma,
dma_addr_t addr, dma_addr_t *len,
DMADirection dir);
static inline void *dma_memory_map(DMAContext *dma,
dma_addr_t addr, dma_addr_t *len,
DMADirection dir)
{
if (!dma_has_iommu(dma)) {
target_phys_addr_t xlen = *len;
void *p;
p = cpu_physical_memory_map(addr, &xlen,
dir == DMA_DIRECTION_FROM_DEVICE);
*len = xlen;
return p;
} else {
return iommu_dma_memory_map(dma, addr, len, dir);
}
}
void iommu_dma_memory_unmap(DMAContext *dma,
void *buffer, dma_addr_t len,
DMADirection dir, dma_addr_t access_len);
static inline void dma_memory_unmap(DMAContext *dma,
void *buffer, dma_addr_t len,
DMADirection dir, dma_addr_t access_len)
{
if (!dma_has_iommu(dma)) {
cpu_physical_memory_unmap(buffer, (target_phys_addr_t)len,
dir == DMA_DIRECTION_FROM_DEVICE,
access_len);
} else {
iommu_dma_memory_unmap(dma, buffer, len, dir, access_len);
}
}
#define DEFINE_LDST_DMA(_lname, _sname, _bits, _end) \
static inline uint##_bits##_t ld##_lname##_##_end##_dma(DMAContext *dma, \
dma_addr_t addr) \
{ \
uint##_bits##_t val; \
dma_memory_read(dma, addr, &val, (_bits) / 8); \
return _end##_bits##_to_cpu(val); \
} \
static inline void st##_sname##_##_end##_dma(DMAContext *dma, \
dma_addr_t addr, \
uint##_bits##_t val) \
{ \
val = cpu_to_##_end##_bits(val); \
dma_memory_write(dma, addr, &val, (_bits) / 8); \
}
static inline uint8_t ldub_dma(DMAContext *dma, dma_addr_t addr)
{
uint8_t val;
dma_memory_read(dma, addr, &val, 1);
return val;
}
static inline void stb_dma(DMAContext *dma, dma_addr_t addr, uint8_t val)
{
dma_memory_write(dma, 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
void dma_context_init(DMAContext *dma, DMATranslateFunc translate,
DMAMapFunc map, DMAUnmapFunc unmap);
struct ScatterGatherEntry {
dma_addr_t base;
dma_addr_t len;
};
void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint, DMAContext *dma);
void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len);
void qemu_sglist_destroy(QEMUSGList *qsg);
#endif
typedef BlockDriverAIOCB *DMAIOFunc(BlockDriverState *bs, int64_t sector_num,
QEMUIOVector *iov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
BlockDriverAIOCB *dma_bdrv_io(BlockDriverState *bs,
QEMUSGList *sg, uint64_t sector_num,
DMAIOFunc *io_func, BlockDriverCompletionFunc *cb,
void *opaque, DMADirection dir);
BlockDriverAIOCB *dma_bdrv_read(BlockDriverState *bs,
QEMUSGList *sg, uint64_t sector,
BlockDriverCompletionFunc *cb, void *opaque);
BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs,
QEMUSGList *sg, uint64_t sector,
BlockDriverCompletionFunc *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(BlockDriverState *bs, BlockAcctCookie *cookie,
QEMUSGList *sg, enum BlockAcctType type);
#endif
