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[PATCH 03/13] dma: Document address_space_map/address_space_unmap() prot
From: |
Philippe Mathieu-Daudé |
Subject: |
[PATCH 03/13] dma: Document address_space_map/address_space_unmap() prototypes |
Date: |
Fri, 4 Sep 2020 17:44:29 +0200 |
Add documentation based on address_space_map / address_space_unmap.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
include/sysemu/dma.h | 30 +++++++++++++++++++++++++++++-
1 file changed, 29 insertions(+), 1 deletion(-)
diff --git a/include/sysemu/dma.h b/include/sysemu/dma.h
index 80c5bc3e02d..19bc9ad1b69 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 +125,20 @@ 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 DMA controller
+ * 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 +152,20 @@ 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)
--
2.26.2
- [PATCH 00/13] dma: Let the DMA API take MemTxAttrs argument and propagate MemTxResult, Philippe Mathieu-Daudé, 2020/09/04
- [PATCH 01/13] pci: pass along the return value of dma_memory_rw, Philippe Mathieu-Daudé, 2020/09/04
- [PATCH 02/13] docs/devel/loads-stores: Add regexp for DMA functions, Philippe Mathieu-Daudé, 2020/09/04
- [PATCH 03/13] dma: Document address_space_map/address_space_unmap() prototypes,
Philippe Mathieu-Daudé <=
- [PATCH 04/13] dma: Let dma_memory_set() propagate MemTxResult, Philippe Mathieu-Daudé, 2020/09/04
- [PATCH 05/13] dma: Let dma_memory_rw() propagate MemTxResult, Philippe Mathieu-Daudé, 2020/09/04
- [PATCH 06/13] dma: Let dma_memory_read() propagate MemTxResult, Philippe Mathieu-Daudé, 2020/09/04