在哪里开始学习linux的DMA /设备驱动程序/内存分配 [英] Where to start learning about linux DMA / device drivers / memory allocation

问题描述

我正在移植/调试一个设备驱动程序（由另一个内核模块使用），并面临一个死胡同，因为dma_sync_single_for_device（）失败，内核哎呀。

I'm porting / debugging a device driver (that is used by another kernel module) and facing a dead end because dma_sync_single_for_device() fails with an kernel oops.

我不知道该功能应该做什么，谷歌搜索不是真的有帮助，所以我可能需要总体了解更多的这些东西。

I have no clue what that function is supposed to do and googling does not really help, so I probably need to learn more about this stuff in total.

问题是，在哪里开始？

哦，是的，如果它是相关的，代码应该运行在PowerPC上（而Linux是OpenWRT）

Oh yeah, in case it is relevant, the code is supposed to run on a PowerPC (and the linux is OpenWRT)

编辑：
在线资源优先（书需要几天交付：）

On-line resources preferrable (books take a few days to be delivered :)

推荐答案

在线：

Linux slab分配器的解剖

了解Linux虚拟内存管理器

Linux设备驱动程序，第三版

Linux内核模块编程指南

在Linux中编写设备驱动程序：简要教程

图书：

Linux内核开发（第2版）

基本Linux设备驱动程序（只有前4 - 5章）

Essential Linux Device Drivers ( Only the first 4 - 5 chapters )

有用的资源：

Linux交叉引用（可搜索所有内核源代码内核）

the Linux Cross Reference ( Searchable Kernel Source for all Kernels )

API中的更改2 .6内核系列

dma_sync_single_for_device 调用 dma_sync_single_range_for_cpu 在文件中有一点进一步，这是源文档（我认为即使这是对于arm，接口和行为是一样的）：

dma_sync_single_for_device calls dma_sync_single_range_for_cpu a little further up in the file and this is the source documentation ( I assume that even though this is for arm the interface and behavior are the same ):

/**
 380 * dma_sync_single_range_for_cpu
 381 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 382 * @handle: DMA address of buffer
 383 * @offset: offset of region to start sync
 384 * @size: size of region to sync
 385 * @dir: DMA transfer direction (same as passed to dma_map_single)
 386 *
 387 * Make physical memory consistent for a single streaming mode DMA
 388 * translation after a transfer.
 389 *
 390 * If you perform a dma_map_single() but wish to interrogate the
 391 * buffer using the cpu, yet do not wish to teardown the PCI dma
 392 * mapping, you must call this function before doing so.  At the
 393 * next point you give the PCI dma address back to the card, you
 394 * must first the perform a dma_sync_for_device, and then the
 395 * device again owns the buffer.
 396 */

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