llvmpipe seems to require this ioctl under normal operation, which makes it hard to use rr to debug an application that uses OpenGL to render its UI (e.g. something written in Qt Quick). Tested with rr 5.8.0 built from commit 946378b. Ba...
src=dma_alloc_writecombine(NULL,BUF_SIZE,&src_phys,GFP_KERNEL); if(NULL==src){ printk("can't alloc buffer for src \n"); return-ENOMEM; /*为目的分配内存对应的缓存区 */ dst=dma_alloc_writecombine(NULL,BUF_SIZE,&dst_phys,GFP_KERNEL); if(NULL==dst){ printk("can't alloc buffer for...
dma-buf: Update docs for SYNC ioctl Just a bit of wording polish plus mentioning that it can fail and must be restarted. Requested by Sumit. v2: Fix them typos (Hans). Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tiago Vignatti <tiago.vignatti@intel.com> Cc: Stéphane Marchesin ...
I can see that the DMA_BUF_IOCTL_PHYS is necessary to actually sync the CPU cache with the DRAM (which is what DMA_BUF_IOCTL_SYNC should do, but it's broken in the NXP kernel). But what issues does the broken DMA_BUF_IOCTL_SYNC cause? Furthermore, will this ...
static u32 dst_phys; static struct class *cls; static volatile struct s3c_dma_regs *dma_regs; static DECLARE_WAIT_QUEUE_HEAD(dma_waitq); // 中断事件标志, 中断服务程序将它置1,ioctl将它清0 // static volatile int ev_dma = 0; static int s3c_dma_ioctl(struct inode *inode, struct file ...
根据2.1的描述我们可以知道,如果在ioctl的dma_map参数里面,dma_map.iova的值填dma_map.vaddr,那么dma_map.iova通过iommu找到的物理地址和dma_map.vaddr通过mmu找到的物理地址是一样的。这也就解释了为啥调用rte_pkmtbuf_alloc出来的rte_mbuf,rte_mbuf->buf_addr和rte_mbuf->buf_iova相等的原因。
int ioctl(int client_fd, ION_IOC_ALLOC, struct ion_allocation_data *allocation_data) This call returns a buffer represented byion_handlewhich is not a CPU-accessible buffer pointer. The handle can only be used to obtain a file descriptor for buffer sharing as follows: ...
dmabuf=vremap(0x1F00000 /*31MB*/, 0x100000 /* 1MB */ ); 我自己分配DMA缓冲区的实现在allocator.c模块(和一个相配的头文件)中。你可以在src/misc-modules的示例文件中找到一个版本,最新版本总可以在我的FTP站点找到:ftp://ftp.systemy.it/pub/develop。你也可以找核心补丁bigphysarea,它和我的分配程...
*//* 休眠 */wait_event_interruptible(dma_waitq,ev_dma);if(memcmp(src,dst,BUF_SIZE)==0){printk("MEM_CPY_DMA OK\n");}else{printk("MEM_CPY_DMA ERROR\n");}break;}}return0;}staticstructfile_operationsdma_fops={.owner=THIS_MODULE,.ioctl=s3c_dma_ioctl,};staticirqreturn_ts3c_dma_irq...
DriverStudio开发PCI设备DMA数据传输,DriverWizard向导可以创建基本的wDM驱动程序框架,包括总线类型,地址空间,中断源,DMA资源,以及IOCTL(i/o控制代码)的定义等等。详细情况可参看DriverStudio的帮助文档,以下主要介绍如何用DriverWorks编写DMA方式的驱动程序。