diff options
| author | Philippe Mathieu-Daudé <philmd@redhat.com> | 2020-10-23 17:19:16 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-12-10 12:15:01 -0500 |
| commit | 9c211ad2ca09f47dc5563107a66c84141c966b7a (patch) | |
| tree | e3331782fa0388ac2e5b9e800df58bc45de1a52c /include | |
| parent | 169cbac12d4fad5922619a0b64ad0aa66e9365a7 (diff) | |
dma: Document address_space_map/address_space_unmap() prototypes
Add documentation based on address_space_map / address_space_unmap.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201023151923.3243652-4-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/sysemu/dma.h | 29 |
1 files changed, 28 insertions, 1 deletions
diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h index 80c5bc3e02..c6e12b4c24 100644 --- a/include/sysemu/dma.h +++ b/include/sysemu/dma.h @@ -1,7 +1,7 @@ /* * DMA helper functions * - * Copyright (c) 2009 Red Hat + * Copyright (c) 2009, 2020 Red Hat * * This work is licensed under the terms of the GNU General Public License * (GNU GPL), version 2 or later. @@ -125,6 +125,19 @@ static inline int dma_memory_write(AddressSpace *as, dma_addr_t addr, int dma_memory_set(AddressSpace *as, dma_addr_t addr, uint8_t c, dma_addr_t len); +/** + * address_space_map: Map a physical memory region into a host virtual address. + * + * May map a subset of the requested range, given by and returned in @plen. + * May return %NULL and set *@plen to zero(0), if resources needed to perform + * the mapping are exhausted. + * Use only for reads OR writes - not for read-modify-write operations. + * + * @as: #AddressSpace to be accessed + * @addr: address within that address space + * @len: pointer to length of buffer; updated on return + * @dir: indicates the transfer direction + */ static inline void *dma_memory_map(AddressSpace *as, dma_addr_t addr, dma_addr_t *len, DMADirection dir) @@ -138,6 +151,20 @@ static inline void *dma_memory_map(AddressSpace *as, return p; } +/** + * address_space_unmap: Unmaps a memory region previously mapped + * by dma_memory_map() + * + * Will also mark the memory as dirty if @dir == %DMA_DIRECTION_FROM_DEVICE. + * @access_len gives the amount of memory that was actually read or written + * by the caller. + * + * @as: #AddressSpace used + * @buffer: host pointer as returned by address_space_map() + * @len: buffer length as returned by address_space_map() + * @dir: indicates the transfer direction + * @access_len: amount of data actually transferred + */ static inline void dma_memory_unmap(AddressSpace *as, void *buffer, dma_addr_t len, DMADirection dir, dma_addr_t access_len) |