Archipelago » qemu

#include "kvm.h"

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 int dma_memory_rw_relaxed(DMAContext *dma, dma_addr_t addr,

                                        void *buf, dma_addr_t len,

                                        DMADirection 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);

}