324 lines
12 KiB
C
324 lines
12 KiB
C
/*
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* DMA helper functions
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*
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* Copyright (c) 2009, 2020 Red Hat
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*
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* This work is licensed under the terms of the GNU General Public License
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* (GNU GPL), version 2 or later.
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*/
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#ifndef DMA_H
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#define DMA_H
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#include "exec/memory.h"
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#include "exec/address-spaces.h"
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#include "block/block.h"
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#include "block/accounting.h"
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typedef enum {
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DMA_DIRECTION_TO_DEVICE = 0,
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DMA_DIRECTION_FROM_DEVICE = 1,
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} DMADirection;
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/*
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* When an IOMMU is present, bus addresses become distinct from
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* CPU/memory physical addresses and may be a different size. Because
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* the IOVA size depends more on the bus than on the platform, we more
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* or less have to treat these as 64-bit always to cover all (or at
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* least most) cases.
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*/
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typedef uint64_t dma_addr_t;
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#define DMA_ADDR_BITS 64
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#define DMA_ADDR_FMT "%" PRIx64
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typedef struct ScatterGatherEntry ScatterGatherEntry;
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struct QEMUSGList {
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ScatterGatherEntry *sg;
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int nsg;
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int nalloc;
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dma_addr_t size;
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DeviceState *dev;
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AddressSpace *as;
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};
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static inline void dma_barrier(AddressSpace *as, DMADirection dir)
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{
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/*
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* This is called before DMA read and write operations
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* unless the _relaxed form is used and is responsible
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* for providing some sane ordering of accesses vs
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* concurrently running VCPUs.
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*
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* Users of map(), unmap() or lower level st/ld_*
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* operations are responsible for providing their own
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* ordering via barriers.
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*
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* This primitive implementation does a simple smp_mb()
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* before each operation which provides pretty much full
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* ordering.
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*
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* A smarter implementation can be devised if needed to
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* use lighter barriers based on the direction of the
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* transfer, the DMA context, etc...
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*/
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smp_mb();
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}
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/* Checks that the given range of addresses is valid for DMA. This is
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* useful for certain cases, but usually you should just use
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* dma_memory_{read,write}() and check for errors */
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static inline bool dma_memory_valid(AddressSpace *as,
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dma_addr_t addr, dma_addr_t len,
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DMADirection dir, MemTxAttrs attrs)
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{
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return address_space_access_valid(as, addr, len,
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dir == DMA_DIRECTION_FROM_DEVICE,
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attrs);
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}
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static inline MemTxResult dma_memory_rw_relaxed(AddressSpace *as,
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dma_addr_t addr,
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void *buf, dma_addr_t len,
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DMADirection dir,
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MemTxAttrs attrs)
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{
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return address_space_rw(as, addr, attrs,
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buf, len, dir == DMA_DIRECTION_FROM_DEVICE);
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}
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static inline MemTxResult dma_memory_read_relaxed(AddressSpace *as,
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dma_addr_t addr,
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void *buf, dma_addr_t len)
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{
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return dma_memory_rw_relaxed(as, addr, buf, len,
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DMA_DIRECTION_TO_DEVICE,
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MEMTXATTRS_UNSPECIFIED);
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}
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static inline MemTxResult dma_memory_write_relaxed(AddressSpace *as,
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dma_addr_t addr,
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const void *buf,
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dma_addr_t len)
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{
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return dma_memory_rw_relaxed(as, addr, (void *)buf, len,
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DMA_DIRECTION_FROM_DEVICE,
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MEMTXATTRS_UNSPECIFIED);
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}
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/**
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* dma_memory_rw: Read from or write to an address space from DMA controller.
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*
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* Return a MemTxResult indicating whether the operation succeeded
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* or failed (eg unassigned memory, device rejected the transaction,
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* IOMMU fault).
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*
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* @as: #AddressSpace to be accessed
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* @addr: address within that address space
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* @buf: buffer with the data transferred
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* @len: the number of bytes to read or write
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* @dir: indicates the transfer direction
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* @attrs: memory transaction attributes
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*/
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static inline MemTxResult dma_memory_rw(AddressSpace *as, dma_addr_t addr,
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void *buf, dma_addr_t len,
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DMADirection dir, MemTxAttrs attrs)
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{
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dma_barrier(as, dir);
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return dma_memory_rw_relaxed(as, addr, buf, len, dir, attrs);
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}
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/**
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* dma_memory_read: Read from an address space from DMA controller.
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*
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* Return a MemTxResult indicating whether the operation succeeded
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* or failed (eg unassigned memory, device rejected the transaction,
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* IOMMU fault). Called within RCU critical section.
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*
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* @as: #AddressSpace to be accessed
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* @addr: address within that address space
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* @buf: buffer with the data transferred
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* @len: length of the data transferred
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* @attrs: memory transaction attributes
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*/
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static inline MemTxResult dma_memory_read(AddressSpace *as, dma_addr_t addr,
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void *buf, dma_addr_t len,
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MemTxAttrs attrs)
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{
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return dma_memory_rw(as, addr, buf, len,
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DMA_DIRECTION_TO_DEVICE, attrs);
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}
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/**
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* address_space_write: Write to address space from DMA controller.
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*
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* Return a MemTxResult indicating whether the operation succeeded
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* or failed (eg unassigned memory, device rejected the transaction,
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* IOMMU fault).
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*
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* @as: #AddressSpace to be accessed
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* @addr: address within that address space
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* @buf: buffer with the data transferred
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* @len: the number of bytes to write
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* @attrs: memory transaction attributes
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*/
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static inline MemTxResult dma_memory_write(AddressSpace *as, dma_addr_t addr,
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const void *buf, dma_addr_t len,
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MemTxAttrs attrs)
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{
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return dma_memory_rw(as, addr, (void *)buf, len,
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DMA_DIRECTION_FROM_DEVICE, attrs);
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}
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/**
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* dma_memory_set: Fill memory with a constant byte from DMA controller.
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*
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* Return a MemTxResult indicating whether the operation succeeded
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* or failed (eg unassigned memory, device rejected the transaction,
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* IOMMU fault).
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*
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* @as: #AddressSpace to be accessed
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* @addr: address within that address space
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* @c: constant byte to fill the memory
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* @len: the number of bytes to fill with the constant byte
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* @attrs: memory transaction attributes
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*/
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MemTxResult dma_memory_set(AddressSpace *as, dma_addr_t addr,
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uint8_t c, dma_addr_t len, MemTxAttrs attrs);
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/**
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* address_space_map: Map a physical memory region into a host virtual address.
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*
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* May map a subset of the requested range, given by and returned in @plen.
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* May return %NULL and set *@plen to zero(0), if resources needed to perform
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* the mapping are exhausted.
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* Use only for reads OR writes - not for read-modify-write operations.
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*
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* @as: #AddressSpace to be accessed
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* @addr: address within that address space
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* @len: pointer to length of buffer; updated on return
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* @dir: indicates the transfer direction
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* @attrs: memory attributes
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*/
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static inline void *dma_memory_map(AddressSpace *as,
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dma_addr_t addr, dma_addr_t *len,
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DMADirection dir, MemTxAttrs attrs)
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{
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hwaddr xlen = *len;
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void *p;
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p = address_space_map(as, addr, &xlen, dir == DMA_DIRECTION_FROM_DEVICE,
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attrs);
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*len = xlen;
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return p;
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}
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/**
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* address_space_unmap: Unmaps a memory region previously mapped
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* by dma_memory_map()
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*
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* Will also mark the memory as dirty if @dir == %DMA_DIRECTION_FROM_DEVICE.
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* @access_len gives the amount of memory that was actually read or written
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* by the caller.
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*
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* @as: #AddressSpace used
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* @buffer: host pointer as returned by address_space_map()
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* @len: buffer length as returned by address_space_map()
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* @dir: indicates the transfer direction
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* @access_len: amount of data actually transferred
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*/
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static inline void dma_memory_unmap(AddressSpace *as,
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void *buffer, dma_addr_t len,
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DMADirection dir, dma_addr_t access_len)
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{
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address_space_unmap(as, buffer, (hwaddr)len,
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dir == DMA_DIRECTION_FROM_DEVICE, access_len);
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}
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#define DEFINE_LDST_DMA(_lname, _sname, _bits, _end) \
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static inline MemTxResult ld##_lname##_##_end##_dma(AddressSpace *as, \
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dma_addr_t addr, \
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uint##_bits##_t *pval, \
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MemTxAttrs attrs) \
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{ \
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MemTxResult res = dma_memory_read(as, addr, pval, (_bits) / 8, attrs); \
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_end##_bits##_to_cpus(pval); \
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return res; \
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} \
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static inline MemTxResult st##_sname##_##_end##_dma(AddressSpace *as, \
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dma_addr_t addr, \
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uint##_bits##_t val, \
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MemTxAttrs attrs) \
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{ \
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val = cpu_to_##_end##_bits(val); \
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return dma_memory_write(as, addr, &val, (_bits) / 8, attrs); \
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}
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static inline MemTxResult ldub_dma(AddressSpace *as, dma_addr_t addr,
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uint8_t *val, MemTxAttrs attrs)
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{
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return dma_memory_read(as, addr, val, 1, attrs);
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}
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static inline MemTxResult stb_dma(AddressSpace *as, dma_addr_t addr,
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uint8_t val, MemTxAttrs attrs)
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{
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return dma_memory_write(as, addr, &val, 1, attrs);
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}
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DEFINE_LDST_DMA(uw, w, 16, le);
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DEFINE_LDST_DMA(l, l, 32, le);
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DEFINE_LDST_DMA(q, q, 64, le);
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DEFINE_LDST_DMA(uw, w, 16, be);
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DEFINE_LDST_DMA(l, l, 32, be);
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DEFINE_LDST_DMA(q, q, 64, be);
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#undef DEFINE_LDST_DMA
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struct ScatterGatherEntry {
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dma_addr_t base;
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dma_addr_t len;
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};
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void qemu_sglist_init(QEMUSGList *qsg, DeviceState *dev, int alloc_hint,
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AddressSpace *as);
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void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len);
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void qemu_sglist_destroy(QEMUSGList *qsg);
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typedef BlockAIOCB *DMAIOFunc(int64_t offset, QEMUIOVector *iov,
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BlockCompletionFunc *cb, void *cb_opaque,
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void *opaque);
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BlockAIOCB *dma_blk_io(AioContext *ctx,
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QEMUSGList *sg, uint64_t offset, uint32_t align,
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DMAIOFunc *io_func, void *io_func_opaque,
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BlockCompletionFunc *cb, void *opaque, DMADirection dir);
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BlockAIOCB *dma_blk_read(BlockBackend *blk,
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QEMUSGList *sg, uint64_t offset, uint32_t align,
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BlockCompletionFunc *cb, void *opaque);
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BlockAIOCB *dma_blk_write(BlockBackend *blk,
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QEMUSGList *sg, uint64_t offset, uint32_t align,
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BlockCompletionFunc *cb, void *opaque);
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MemTxResult dma_buf_read(void *ptr, dma_addr_t len, dma_addr_t *residual,
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QEMUSGList *sg, MemTxAttrs attrs);
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MemTxResult dma_buf_write(void *ptr, dma_addr_t len, dma_addr_t *residual,
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QEMUSGList *sg, MemTxAttrs attrs);
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void dma_acct_start(BlockBackend *blk, BlockAcctCookie *cookie,
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QEMUSGList *sg, enum BlockAcctType type);
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/**
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* dma_aligned_pow2_mask: Return the address bit mask of the largest
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* power of 2 size less or equal than @end - @start + 1, aligned with @start,
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* and bounded by 1 << @max_addr_bits bits.
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*
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* @start: range start address
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* @end: range end address (greater than @start)
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* @max_addr_bits: max address bits (<= 64)
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*/
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uint64_t dma_aligned_pow2_mask(uint64_t start, uint64_t end,
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int max_addr_bits);
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#endif
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