Re: [PATCH v3] ad7877: keep dma rx buffers in seperate cache lines

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From: Alan Cox
Date: Tuesday, May 11, 2010 - 3:37 pm

> SPI transfer into a DMA safe buffer.  what is the exact API to

If you are embedding structures then one solution is to cheat a bit and
make the structure, compiler and existing kernel compile abuse do the
work. Something like

struct {
	void *except_where_prohibited;
	long boat;
	unsigned photograph;

	u8 pad[0] __cacheline_aligned;
}..

ought to do the trick providing you align the start of the object - which
should happen naturally with kmalloc or dma_* apis


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Messages in current thread:
[PATCH] ad7877: fix spi word size to 16 bit, Oskar Schirmer, (Thu May 6, 3:37 am)
RE: [PATCH] ad7877: fix spi word size to 16 bit, Hennerich, Michael, (Thu May 6, 4:18 am)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Mike Frysinger, (Thu May 6, 11:26 am)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Daniel Glöckner, (Fri May 7, 2:41 am)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Mike Frysinger, (Fri May 7, 11:23 am)
Re: [PATCH v3] ad7877: keep dma rx buffers in seperate cac ..., Christoph Lameter, (Tue May 11, 6:57 am)
Re: [PATCH v3] ad7877: keep dma rx buffers in seperate cac ..., Christoph Lameter, (Tue May 11, 1:21 pm)
Re: [PATCH v3] ad7877: keep dma rx buffers in seperate cac ..., Christoph Lameter, (Tue May 11, 1:46 pm)
Re: [PATCH v3] ad7877: keep dma rx buffers in seperate cac ..., Alan Cox, (Tue May 11, 3:37 pm)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Dmitry Torokhov, (Thu May 13, 12:53 am)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Oskar Schirmer, (Sat May 15, 11:15 am)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Mike Frysinger, (Sun May 16, 12:25 pm)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Oskar Schirmer, (Mon May 17, 12:29 am)
RE: [PATCH] ad7877: fix spi word size to 16 bit, Hennerich, Michael, (Mon May 17, 1:14 am)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Oskar Schirmer, (Mon May 17, 1:41 am)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Mike Frysinger, (Mon May 17, 4:49 pm)
RE: [PATCH] ad7877: fix spi word size to 16 bit, H Hartley Sweeten, (Mon May 17, 5:18 pm)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Oskar Schirmer, (Tue May 18, 1:32 am)
[PATCH v2] ad7877: fix spi word size to 16 bit, Oskar Schirmer, (Tue May 18, 1:34 am)
Re: [PATCH] ad7877: fix spi word size to 16 bit, Daniel Glöckner, (Tue May 18, 2:37 am)