Messages in this thread | | | Date | Fri, 05 Apr 2013 22:59:59 +0200 | From | Gregory CLEMENT <> | Subject | Re: [PATCH v2 1/9] arm: mvebu: Limit the DMA zone when LPAE is selected |
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On 04/05/2013 10:41 PM, Arnd Bergmann wrote: > On Friday 05 April 2013, Gregory CLEMENT wrote: >> When LPAE is activated on Armada XP, all registers and IOs are still >> 32bit, the 40bit extension is on the CPU to DRAM path (windows) only. >> That means that all the DMA transfer are restricted to the low 32 bits >> address space. This is limitation is achieved by selecting ZONE_DMA. >> >> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> > > > Shouldn't that be ZONE_DMA32? >
Well common code for ARM don't manage the ZONE_DMA32. Whereas with ZONE_DMA, setup_dma_zone() in arch/arm/mm/init.c does exactly what I want: setting arm_dma_limit to 0xffffffff.
ZONE_DMA32 is used on arm64 however.
> Arnd >
-- Gregory Clement, Free Electrons Kernel, drivers, real-time and embedded Linux development, consulting, training and support. http://free-electrons.com
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