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[PATCH v2 03/16] dma: Document address_space_map/address_space_unmap() p
From: |
Philippe Mathieu-Daudé |
Subject: |
[PATCH v2 03/16] dma: Document address_space_map/address_space_unmap() prototypes |
Date: |
Thu, 1 Oct 2020 19:21:46 +0200 |
From: Philippe Mathieu-Daudé <philmd@redhat.com>
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>
---
include/sysemu/dma.h | 29 ++++++++++++++++++++++++++++-
1 file changed, 28 insertions(+), 1 deletion(-)
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)
--
2.26.2