On Wed, Feb 12, 2014 at 01:59:11PM -0700, Bjorn Helgaas wrote: > On Wed, Feb 05, 2014 at 03:52:43PM +0900, Magnus Damm wrote: > > PCI: rcar: Driver model and physical address space update > > > > [PATCH 01/04] PCI: rcar: Register each instance independently > > [PATCH 02/04] PCI: rcar: Break out window size handling > > [PATCH 03/04] PCI: rcar: Add DMABOUNCE support > > [PATCH 04/04] PCI: rcar: Enable BOUNCE in case of HIGHMEM > > > > These patches update the pci-rcar-gen2.c driver in various ways > > including cleanups for driver model interface (1/4), readability > > update (2/4) and also bounce buffer support (3/4, 4/4). Basically > > the first two are just cleanups and the rest are fixes. > > > > As it is today without these patches the system memory start address > > is hard coded at 0x4000000 and the window is fixed at 1GiB. So we > > have board specific code hidden in the driver which is good to avoid. > > > > With these hard coded board specific constants there are some error cases > > that are not handled, in particular the issue that only maximum 1GiB of > > physical address space can be used for bus mastering with a single window. > > The common case of using ARM CONFIG_VMSPLIT_3G results in no visible issues > > as long as CONFIG_BOUNCE is used, but other CONFIG_VMSPLIT settings will > > break due to the hard coded 1GiB window not being enough. It has been > > verified that reducing the window size to 256MB makes the driver behave > > the same with VMSPLIT_3G as 1GiB window size and other VMSPLIT settings. > > > > To handle the maximum 1GiB physical address space limitation two types > > of bounce buffers are added. The ARM specific DMABOUNCE code is in 3/4 > > hooked up to a chunk of local memory that is also handed of as coherent > > memory to the pci devices hanging off the PCI bridge. The driver makes > > sure to set the window so the local memory is always included. When the > > PCI devices are operating and in case memory is used outside the window > > then the DMABOUNCE buffers kicks in. This makes the driver support all > > kinds of VMSPLIT settings and window sizes. The BOUNCE code in 4/4 is > > selected to make sure bounce buffers are used for HIGHMEM. > > > > With these patches this driver can be used with or without CMA and > > with or without DMA zone. Basically the system wide memory setup is > > left to the user. If a DMA zone is used then the PCI window will > > be setup to cover that. Same thing with CMA. > > > > Tested with USB storage using LPAE and various VMSPLIT settings together > > with renesas git tag renesas-devel-v3.14-rc1-20140204 from kernel.org > > > > Signed-off-by: Magnus Damm <damm@xxxxxxxxxxxxx> > > --- > > > > Written against renesas.git tag renesas-devel-v3.14-rc1-20140204 > > > > drivers/pci/host/Kconfig | 3 > > drivers/pci/host/pci-rcar-gen2.c | 367 +++++++++++++++++++++++++++++++------- > > 2 files changed, 306 insertions(+), 64 deletions(-) > > Simon, if you want to ack these, I'll be happy to merge them for v3.15. > I'm not really qualified to review them myself. Hi Bjorn, Magnus has reposted these patches as part of a larger series which includes some patches of his own. That series is "[PATCH 00/08] PCI: rcar: Recent driver patches from Ben Dooks and me". I am happy with it and will Ack it. Could you consider merging it? -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
