/* * 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 #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; }; #if defined(TARGET_PHYS_ADDR_BITS) /* * 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