--- /dev/null
+/*
+ * 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 "exec/address-spaces.h"
+#include "hw/hw.h"
+#include "block/block.h"
+#include "block/accounting.h"
+#include "sysemu/kvm.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...
+ */
+ 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(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(BlockBackend *blk, int64_t sector_num,
+ QEMUIOVector *iov, int nb_sectors,
+ BlockCompletionFunc *cb, void *opaque);
+
+BlockAIOCB *dma_blk_io(BlockBackend *blk,
+ QEMUSGList *sg, uint64_t sector_num,
+ DMAIOFunc *io_func, BlockCompletionFunc *cb,
+ void *opaque, DMADirection dir);
+BlockAIOCB *dma_blk_read(BlockBackend *blk,
+ QEMUSGList *sg, uint64_t sector,
+ BlockCompletionFunc *cb, void *opaque);
+BlockAIOCB *dma_blk_write(BlockBackend *blk,
+ QEMUSGList *sg, uint64_t sector,
+ 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
Code Review / kvmfornfv.git / blobdiff