Re: [PATCH V3 0/2] Tegra PCIe end point config space map code refactoring

[Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

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On Mon, Dec 04, 2017 at 11:23:48PM +0530, Vidya Sagar wrote:
> PCIe host controller in Tegra SoCs has 1GB of aperture available
> for mapping end points config space, IO and BARs. In that, currently
> 256MB is being reserved for mapping end points configuration space
> which leaves less memory space available for mapping end points BARs
> on some of the platforms.
> This patch series attempts to map only 4K space from 1GB aperture to
> access end points configuration space.
> 
> Currently, this change can benefit T20 and T186 in saving (i.e. repurposed
> to use for BAR mapping) physical space as well as kernel virtual mapping space,
> it saves only kernel virtual address space in T30, T124, T132 and T210.
> 
> NOTE: Since T186 PCIe DT entry is not yet present in main line (it is currently
> merged to 'for-4.15/arm64/dt' branch), nothing gets broken with this change for T186.
> For older platforms (T20, T30, T124, T132, T210), this change works fine without any
> DT modifications
> 
> Testing Done on T124, T210 & T186:
>  Enumeration and basic functionality of immediate devices
>  Enumeration of devices behind a PCIe switch
>  Complete 4K configuration space access
> 
> Vidya Sagar (2):
>   PCI: tegra: refactor config space mapping code
>   ARM64: tegra: limit PCIe config space mapping to 4K for T186
> 
>  arch/arm64/boot/dts/nvidia/tegra186.dtsi |   8 +-
>  drivers/pci/host/pci-tegra.c             | 125 ++++++++++---------------------
>  2 files changed, 44 insertions(+), 89 deletions(-)

Hi Bjorn,

there's a bunch of PCI related patches for Tegra floating around on the
lists. I'm wondering if you'd be okay if I pick those up into the Tegra
tree after they've been reviewed and send you a pull request later on
(say around v4.15-rc6). That would allow me to get things cooking in
linux-next for a bit and get broader testing in addition to the
flexibility to patch things up if they break.

Thierry

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