Re: [RFC 3/4] dma-direct: add dma_direct_min_mask

2019-07-24 Thread Nicolas Saenz Julienne
On Wed, 2019-07-24 at 15:56 +0200, Christoph Hellwig wrote: > On Wed, Jul 24, 2019 at 02:51:24PM +0100, Catalin Marinas wrote: > > I think it may be better if we have both ZONE_DMA and ZONE_DMA32 on > > arm64. ZONE_DMA would be based on the smallest dma-ranges as described > > in the DT while DMA32

Re: [RFC 3/4] dma-direct: add dma_direct_min_mask

2019-07-24 Thread Christoph Hellwig
On Wed, Jul 24, 2019 at 02:51:24PM +0100, Catalin Marinas wrote: > I think it may be better if we have both ZONE_DMA and ZONE_DMA32 on > arm64. ZONE_DMA would be based on the smallest dma-ranges as described > in the DT while DMA32 covers the first naturally aligned 4GB of RAM > (unchanged). When a

Re: [RFC 3/4] dma-direct: add dma_direct_min_mask

2019-07-24 Thread Catalin Marinas
On Fri, Jul 19, 2019 at 03:08:52PM +0200, Nicolas Saenz Julienne wrote: > On Thu, 2019-07-18 at 13:18 +0200, Nicolas Saenz Julienne wrote: > > On Thu, 2019-07-18 at 11:15 +0200, Christoph Hellwig wrote: > > > On Wed, Jul 17, 2019 at 05:31:34PM +0200, Nicolas Saenz Julienne wrote: > > > > Historical

Re: [RFC 3/4] dma-direct: add dma_direct_min_mask

2019-07-19 Thread Nicolas Saenz Julienne
On Thu, 2019-07-18 at 13:18 +0200, Nicolas Saenz Julienne wrote: > On Thu, 2019-07-18 at 11:15 +0200, Christoph Hellwig wrote: > > On Wed, Jul 17, 2019 at 05:31:34PM +0200, Nicolas Saenz Julienne wrote: > > > Historically devices with ZONE_DMA32 have been assumed to be able to > > > address at leas

Re: [RFC 3/4] dma-direct: add dma_direct_min_mask

2019-07-18 Thread Nicolas Saenz Julienne
On Thu, 2019-07-18 at 11:15 +0200, Christoph Hellwig wrote: > On Wed, Jul 17, 2019 at 05:31:34PM +0200, Nicolas Saenz Julienne wrote: > > Historically devices with ZONE_DMA32 have been assumed to be able to > > address at least the lower 4GB of ram for DMA. This is still the defualt > > behavior ye

Re: [RFC 3/4] dma-direct: add dma_direct_min_mask

2019-07-18 Thread Christoph Hellwig
On Wed, Jul 17, 2019 at 05:31:34PM +0200, Nicolas Saenz Julienne wrote: > Historically devices with ZONE_DMA32 have been assumed to be able to > address at least the lower 4GB of ram for DMA. This is still the defualt > behavior yet the Raspberry Pi 4 is limited to the first GB of memory. > This ha

[RFC 3/4] dma-direct: add dma_direct_min_mask

2019-07-17 Thread Nicolas Saenz Julienne
Historically devices with ZONE_DMA32 have been assumed to be able to address at least the lower 4GB of ram for DMA. This is still the defualt behavior yet the Raspberry Pi 4 is limited to the first GB of memory. This has been observed to trigger failures in dma_direct_supported() as the 'min_mask'