作为对poll()的替代,可以使用dma_buf_sync_file_export将DMA缓冲区上的一组fence导出为sync_file。 DMA-BUF统计信息 /sys/kernel/debug/dma_buf/bufinfo提供了系统中每个DMA-BUF的概述。但是,由于debugfs不安全,不能在生产环境中挂载,因此可以使用procfs和sysfs来收集生产系统上的DMA-BUF统计信息。 procfs中的/pro...
Support DMA_BUF_IOCTL_EXPORT_SYNC_FILE ioctl for llvmpipe #3891 Open cebtenzzre opened this issue Dec 18, 2024· 1 comment Open Support DMA_BUF_IOCTL_EXPORT_SYNC_FILE ioctl for llvmpipe #3891 cebtenzzre opened this issue Dec 18, 2024· 1 comment Comments cebtenzzre commented De...
.. kernel-doc:: drivers/dma-buf/sync_file.c :export: .. kernel-doc:: include/linux/sync_file.h :internal: DMA Fence Sync File uABI ~~~ .. kernel-doc:: include/uapi/linux/sync_file.h :internal: Indefinite DMA Fences ~~~37 changes: 15 additions & 22 deletions 37 include/uapi/...
This commit from NXP's gst-plugins-base fork states that DMA_BUF_IOCTL_SYNC should not be used because "it causes issue". https://source.codeaurora.org/external/imx/gst-plugins-base/commit/?h=MM_04.06.04_2112_L5.15.y&id=6d... Which issue is that? I can see ...
(2) 流 DMA 映射(Streaming),通常针对一次 DMA 传输进行映射,在其之后立即取消映射(除非您使用下面的 dma_sync_*),并且硬件可以针对顺序访问进行优化将“流”视为“异步”或“在一致性域之外” (Think of "streaming" as "asynchronous" or "outside the coherency domain") 使用流映射的好例子是: ...
}intdmatest_release(structinode *inode,structfile *filp) {return0; }staticssize_t dmatest_read(structfile *filp,char__user *buf, size_t size, loff_t *ppos) {intret =0;//alloc a desc,and set dst_addr,src_addr,data_size.tx = dev->device_prep_dma_memcpy(chan, dma_dst, dma_src...
我们在调用【dma = dma_map_single(device, buf, size, DMA_TO_DEVICE)】,将数据 buf(虚拟地址) 建立 dma地址映射给device 访问时,返回的类型为 dma_addr_t 的 dma 地址,就是 bus address。该地址可以传给设备用于DMA的物理内存数据读取。 在一些系统中,总线地址和物理地址是一样的(我们可以调用 phy = ...
12 */ 13 14#include <linux/fs.h> 15#include <linux/slab.h> 16#include <linux/dma-buf.h> 17#include <linux/dma-fence.h> 18#include <linux/anon_inodes.h> 19#include <linux/export.h> 20#include <linux/debugfs.h> 21#include <linux/module.h> 22#include <linux/seq_file.h> 23#...
EXPORT_SYMBOL(dma_sync_wait); /** * dma_find_channel - find a channel to carry out the operation * @tx_type: transaction type */ struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type) { return this_cpu_read(channel_table[tx_type]->chan); ...
coherency, DMA_BUF_IOCTL_SYNC must be used to bracket* any CPU access to give the kernel the chance to shuffle memory around if* needed.** Prior to accessing the map, the client must call DMA_BUF_IOCTL_SYNC* with DMA_BUF_SYNC_START and the appropriate read/write flags. Once the* ...