Re: [PATCH 00/14] DMA-mapping framework redesign preparation

2012-02-24 Thread Arnd Bergmann
On Friday 23 December 2011, Marek Szyprowski wrote: > The solution we found is to introduce a new public dma mapping functions > with additional attributes argument: dma_alloc_attrs and > dma_free_attrs(). This way all different kinds of architecture specific > buffer mappings can be hidden behind

RE: [PATCH 00/14] DMA-mapping framework redesign preparation

2012-01-10 Thread Marek Szyprowski
Hello, To help everyone in testing and adapting our patches for his hardware platform I've rebased our patches onto the latest v3.2 Linux kernel and prepared a few GIT branches in our public repository. These branches contain our memory management related patches posted in the following threads:

RE: [PATCH 00/14] DMA-mapping framework redesign preparation

2011-12-28 Thread Marek Szyprowski
Hello, On Tuesday, December 27, 2011 6:53 PM James Bottomley wrote: > On Tue, 2011-12-27 at 09:25 +0100, Marek Szyprowski wrote: > [...] > > > > Usually these drivers don't touch the buffer data at all, so the mapping > > > > in kernel virtual address space is not needed. We can introduce > > > >

RE: [PATCH 00/14] DMA-mapping framework redesign preparation

2011-12-27 Thread James Bottomley
On Tue, 2011-12-27 at 09:25 +0100, Marek Szyprowski wrote: [...] > > > Usually these drivers don't touch the buffer data at all, so the mapping > > > in kernel virtual address space is not needed. We can introduce > > > DMA_ATTRIB_NO_KERNEL_MAPPING attribute which lets kernel to skip/ignore > > > c

RE: [PATCH 00/14] DMA-mapping framework redesign preparation

2011-12-27 Thread Marek Szyprowski
Hello, On Friday, December 23, 2011 5:35 PM Matthew Wilcox wrote: > On Fri, Dec 23, 2011 at 01:27:19PM +0100, Marek Szyprowski wrote: > > The first issue we identified is the fact that on some platform (again, > > mainly ARM) there are several functions for allocating DMA buffers: > > dma_alloc_c

Re: [PATCH 00/14] DMA-mapping framework redesign preparation

2011-12-23 Thread Benjamin Herrenschmidt
On Fri, 2011-12-23 at 09:35 -0700, Matthew Wilcox wrote: > I really think this wants to be a separate function. > dma_alloc_coherent > is for allocating memory to be shared between the kernel and a driver; > we already have dma_map_sg for mapping userspace I/O as an alternative > interface. This f

Re: [PATCH 00/14] DMA-mapping framework redesign preparation

2011-12-23 Thread Matthew Wilcox
On Fri, Dec 23, 2011 at 01:27:19PM +0100, Marek Szyprowski wrote: > The first issue we identified is the fact that on some platform (again, > mainly ARM) there are several functions for allocating DMA buffers: > dma_alloc_coherent, dma_alloc_writecombine and dma_alloc_noncoherent Is this write-com