Hi Russell, From: ext Russell King <rmk@xxxxxxxxxxxxxxxx> Subject: Re: [PATCH 1/1] DSPBRIDGE: cache operation against kernel address instead of user's Date: Sat, 21 Nov 2009 20:17:25 +0100 > On Tue, Nov 17, 2009 at 08:41:08AM +0200, Hiroshi DOYU wrote: > > From: Hiroshi DOYU <Hiroshi.DOYU@xxxxxxxxx> > > Subject: Re: [PATCH 1/1] DSPBRIDGE: cache operation against kernel address instead of user's > > Date: Fri, 13 Nov 2009 12:12:12 +0200 (EET) > > > > > From: "Doyu Hiroshi (Nokia-D/Helsinki)" <hiroshi.doyu@xxxxxxxxx> > > > Subject: [PATCH 1/1] DSPBRIDGE: cache operation against kernel address instead of user's > > > Date: Fri, 6 Nov 2009 13:34:21 +0100 > > > > > > > From: Hiroshi DOYU <Hiroshi.DOYU@xxxxxxxxx> > > > > > > > > Based on the discussion: > > > > http://www.spinics.net/lists/arm-kernel/msg72810.html > > > > > > > > HACK: export "follow_page()" for dspbridge cache operation > > > > > > > > Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@xxxxxxxxx> > > > > --- > > > > Now there's no need for homebrewed cache function because we use > > kernel address and can pass "virt_addr_valid()" check in > > "dma_cache_maint()". > > Note that with the advent of ARMv7/Cortex A9, dma_cache_maint() is going > away - and probably will be gone during the next merge window. There is > no directly equivalent replacement for it - it is being replaced by two > sets of functions, one to be called prior to DMA and another to be called > after DMA has completed. > > In the longer run, it is likely that the 'dmac_*_range' and 'outer_*_range' > will probably also be going away, to be replaced by two new per-cpu methods > along the lines of the above. > > I think this may throw a spanner in the works for this patch, but it's > necessary to make Cortex A9 work. Thank you for updating the status of cache operations. I don't think that none of my patch in this thread can be a generic solution at all, but they are just a hack for VIPT non-aliasing until a generic solution comes. We need to fix some kernel crash at v7_dma_*_range() just right now. Anyway, I am looking forward to your new DMA APIs. -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
