Archipelago » qemu

/*

 * 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 "exec/memory.h"

#include "hw/hw.h"

#include "block/block.h"

#include "sysemu/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

struct DMAContext {

    AddressSpace *as;

};

/* A global DMA context corresponding to the address_space_memory

 * AddressSpace, for sysbus devices which do DMA.

 */

extern DMAContext dma_context_memory;

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();

    }

}

/* 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(DMAContext *dma,

                                    dma_addr_t addr, dma_addr_t len,

                                    DMADirection dir)

{

    return address_space_access_valid(dma->as, addr, len,

                                      dir == DMA_DIRECTION_FROM_DEVICE);

}

static inline int dma_memory_rw_relaxed(DMAContext *dma, dma_addr_t addr,

                                        void *buf, dma_addr_t len,

                                        DMADirection dir)

{

    return address_space_rw(dma->as, addr, buf, len, dir == DMA_DIRECTION_FROM_DEVICE);

}

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 dma_memory_set(DMAContext *dma, dma_addr_t addr, uint8_t c, dma_addr_t len);

static inline void *dma_memory_map(DMAContext *dma,

                                   dma_addr_t addr, dma_addr_t *len,

                                   DMADirection dir)

{

    hwaddr xlen = *len;

    void *p;

    p = address_space_map(dma->as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE);

    *len = xlen;

    return p;

}

static inline void dma_memory_unmap(DMAContext *dma,

                                    void *buffer, dma_addr_t len,

                                    DMADirection dir, dma_addr_t access_len)

{

    address_space_unmap(dma->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(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, AddressSpace *as);

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