linux/Documentation/DMA-API.txt, branch v3.19

DMA-API: Capitalize "CPU" consistently

2014-05-26T23:28:27Z

Sometimes we used "cpu," other times "CPU." Use "CPU" consistently. Suggested-by: Randy Dunlap Signed-off-by: Bjorn Helgaas

DMA-API: Change dma_declare_coherent_memory() CPU address to phys_addr_t

2014-05-20T22:55:23Z

dma_declare_coherent_memory() takes two addresses for a region of memory: a "bus_addr" and a "device_addr". I think the intent is that "bus_addr" is the physical address a *CPU* would use to access the region, and "device_addr" is the bus address the *device* would use to address the region. Rename "bus_addr" to "phys_addr" and change its type to phys_addr_t. Most callers already supply a phys_addr_t for this argument. The others supply a 32-bit integer (a constant, unsigned int, or __u32) and need no change. Use "unsigned long", not phys_addr_t, to hold PFNs. No functional change (this could theoretically fix a truncation in a config with 32-bit dma_addr_t and 64-bit phys_addr_t, but I don't think there are any such cases involving this code). Signed-off-by: Bjorn Helgaas Acked-by: Arnd Bergmann Acked-by: Greg Kroah-Hartman Acked-by: James Bottomley Acked-by: Randy Dunlap

DMA-API: Clarify physical/bus address distinction

2014-05-20T22:54:21Z

The DMA-API documentation sometimes refers to "physical addresses" when it really means "bus addresses." Sometimes these are identical, but they may be different if the bridge leading to the bus performs address translation. Update the documentation to use "bus address" when appropriate. Also, consistently capitalize "DMA", use parens with function names, use dev_printk() in examples, and reword a few sections for clarity. No functional change; documentation changes only. Signed-off-by: Bjorn Helgaas Acked-by: Greg Kroah-Hartman Acked-by: Arnd Bergmann Acked-by: James Bottomley Acked-by: Randy Dunlap

DMA-API: provide a helper to set both DMA and coherent DMA masks

2013-09-17T14:32:37Z

Provide a helper to set both the DMA and coherent DMA masks to the same value - this avoids duplicated code in a number of drivers, sometimes with buggy error handling, and also allows us identify which drivers do things differently. Signed-off-by: Russell King

dma-debug: New interfaces to debug dma mapping errors

2012-10-24T15:06:43Z

Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail to check dma mapping errors on addresses returned by dma_map_single() and dma_map_page() interfaces. This interface clears a flag set by debug_dma_map_page() to indicate that dma_mapping_error() has been called by the driver. When driver does unmap, debug_dma_unmap() checks the flag and if this flag is still set, prints warning message that includes call trace that leads up to the unmap. This interface can be called from dma_mapping_error() routines to enable dma mapping error check debugging. Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with CONFIG_DMA_API_DEBUG enabled and disabled. Signed-off-by: Shuah Khan Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Joerg Roedel

include/linux/dma-mapping.h: add dma_zalloc_coherent()

2011-11-02T23:07:02Z

Lots of driver code does a dma_alloc_coherent() and then zeroes out the memory with a memset. Make it easy for them. Cc: Alexandre Bounine Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dma-mapping: remove dma_is_consistent API

2010-08-11T15:59:21Z

Architectures implement dma_is_consistent() in different ways (some misinterpret the definition of API in DMA-API.txt). So it hasn't been so useful for drivers. We have only one user of the API in tree. Unlikely out-of-tree drivers use the API. Even if we fix dma_is_consistent() in some architectures, it doesn't look useful at all. It was invented long ago for some old systems that can't allocate coherent memory at all. It's better to export only APIs that are definitely necessary for drivers. Let's remove this API. Signed-off-by: FUJITA Tomonori Cc: James Bottomley Reviewed-by: Konrad Rzeszutek Wilk Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Documentation: rename PCI-DMA-mapping.txt to DMA-API-HOWTO.txt

2010-03-12T23:52:43Z

Signed-off-by: FUJITA Tomonori Cc: James Bottomley Cc: "David S. Miller" Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Documentation: remove the PCI DMA API description in DMA-API.txt

2010-03-12T23:52:43Z

- remove the PCI DMA API description in DMA-API.txt - remove the descriptions of dma_unmap macros since PCI-DMA-mapping.txt has the same description. Signed-off-by: FUJITA Tomonori Cc: James Bottomley Cc: "David S. Miller" Reviewed-by: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

dma-mapping: dma-mapping.h: add dma_set_coherent_mask

2010-03-12T23:52:42Z

dma_set_coherent_mask corresponds to pci_set_consistent_dma_mask. This is necessary to move to the generic device model DMA API from the PCI bus specific API in the long term. dma_set_coherent_mask works in the exact same way that pci_set_consistent_dma_mask does. So this patch also changes pci_set_consistent_dma_mask to call dma_set_coherent_mask. Signed-off-by: FUJITA Tomonori Cc: James Bottomley Cc: David S. Miller Cc: Jesse Barnes Cc: Benjamin Herrenschmidt Cc: Russell King Cc: Greg KH Cc: Kay Sievers Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds