[PATCH RFC 24/24] drm/lima: add makefile and kconfig

[Qiang Yu]

On Sun, Jul 15, 2018 at 3:16 AM André Przywara <andre.przywara at arm.com> wrote:
>
> On 07/14/2018 03:18 PM, Qiang Yu wrote:
>
> Hi,
>
> > On Sat, Jul 14, 2018 at 8:07 PM André Przywara <andre.przywara at arm.com> wrote:
> >>
> >> On 07/14/2018 02:14 AM, Qiang Yu wrote:
> >>
> >> Hi,
> >>
> >>> Thanks for your info. What a surprise that exist such a SoC. That
> >>> means I have to
> >>> judge if it's a 64bit CPU in other way than just check ARM64 config.
> >>
> >> Yeah, you should do anyways. Actually you should try to avoid those
> >> explicit checks in the first place. Drivers shouldn't need to care about
> >> the "bit size" of the CPU and Linux provides many ways to automatically
> >> cope with that, with types likes phys_addr_t for instance.
> >> Quickly grep-ing I find "need_dma32" in lima_ttm.c:lima_ttm_init(), is
> >> that the only place you need to check?
> > Yes, mali GPU can only use physical mem within 32bit address space.
>
> Ah, thanks, I was wondering about that.
>
> > So I check ARM64 and ARM_LPAE for possible more than 32bit
> > address space to pass in “need_dma32”.
>
> Mmh, but this is not how I understand this parameter. To me it looks
> like it is a property of the device (GPU and bus), but not the CPU.
> So if Mali 4xx can only do 32-bit DMA, then this parameter should
> *always* be true, regardless of whether the CPU can address more than
> 4GB. If the system is restricted to 32-bit anyways, it should not hurt
> to have it set to true, even though it is not needed in this case.
>
> So you can drop this check altogether and just always pass "true".
This parameter is for TTM to alloc page with GFP_DMA32 flag, I'd love
to always set it if GFP_DMA32 won't cause any trouble on 32bit CPUs.

Regards,
Qiang

>
> Cheers,
> Andre.
>
> >>> On Sat, Jun 16, 2018 at 1:23 AM Andre Przywara <andre.przywara at arm.com> wrote:
> >>>>
> >>>> On 05/23/2018 17:16, Marek Vasut wrote:
> >>>>> On 05/18/2018 11:28 AM, Qiang Yu wrote:
> >>>>>> From: Lima Project Developers <dri-devel at lists.freedesktop.org>
> >>>>>>
> >>>>>> Signed-off-by: Qiang Yu <yuq825 at gmail.com>
> >>>>>> Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
> >>>>>> Signed-off-by: Simon Shields <simon at lineageos.org>
> >>>>>> Signed-off-by: Heiko Stuebner <heiko at sntech.de>
> >>>>>> ---
> >>>>>>  drivers/gpu/drm/Kconfig       |  2 ++
> >>>>>>  drivers/gpu/drm/Makefile      |  1 +
> >>>>>>  drivers/gpu/drm/lima/Kconfig  |  9 +++++++++
> >>>>>>  drivers/gpu/drm/lima/Makefile | 19 +++++++++++++++++++
> >>>>>>  4 files changed, 31 insertions(+)
> >>>>>>  create mode 100644 drivers/gpu/drm/lima/Kconfig
> >>>>>>  create mode 100644 drivers/gpu/drm/lima/Makefile
> >>>>>>
> >>>>>> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> >>>>>> index deeefa7a1773..f00d529ee034 100644
> >>>>>> --- a/drivers/gpu/drm/Kconfig
> >>>>>> +++ b/drivers/gpu/drm/Kconfig
> >>>>>> @@ -289,6 +289,8 @@ source "drivers/gpu/drm/pl111/Kconfig"
> >>>>>>
> >>>>>>  source "drivers/gpu/drm/tve200/Kconfig"
> >>>>>>
> >>>>>> +source "drivers/gpu/drm/lima/Kconfig"
> >>>>>> +
> >>>>>>  # Keep legacy drivers last
> >>>>>>
> >>>>>>  menuconfig DRM_LEGACY
> >>>>>> diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
> >>>>>> index 50093ff4479b..aba686e41d6b 100644
> >>>>>> --- a/drivers/gpu/drm/Makefile
> >>>>>> +++ b/drivers/gpu/drm/Makefile
> >>>>>> @@ -103,3 +103,4 @@ obj-$(CONFIG_DRM_MXSFB)  += mxsfb/
> >>>>>>  obj-$(CONFIG_DRM_TINYDRM) += tinydrm/
> >>>>>>  obj-$(CONFIG_DRM_PL111) += pl111/
> >>>>>>  obj-$(CONFIG_DRM_TVE200) += tve200/
> >>>>>> +obj-$(CONFIG_DRM_LIMA)  += lima/
> >>>>>> diff --git a/drivers/gpu/drm/lima/Kconfig b/drivers/gpu/drm/lima/Kconfig
> >>>>>> new file mode 100644
> >>>>>> index 000000000000..4ce9ac2e8204
> >>>>>> --- /dev/null
> >>>>>> +++ b/drivers/gpu/drm/lima/Kconfig
> >>>>>> @@ -0,0 +1,9 @@
> >>>>>> +
> >>>>>> +config DRM_LIMA
> >>>>>> +       tristate "LIMA (DRM support for ARM Mali 400/450 GPU)"
> >>>>>> +       depends on DRM
> >>>>>> +       depends on ARCH_SUNXI || ARCH_ROCKCHIP || ARCH_EXYNOS || ARCH_MESON
> >>>>>
> >>>>> You can add ARCH_ZYNQMP here too , it has Mali 400 MP2.
> >>>>
> >>>> Well, as Qiang Yu already figured, it seems much smarter to not enumerate
> >>>> every possible platform here.
> >>>> More than that, the Kconfig depends should be strictly technical. There is
> >>>> nothing in this driver which is ARM specific, in fact I managed to compile
> >>>> it for x86-64 as well (with some small fix in a random header file).
> >>>> In fact there are x86-64 based SoCs pairing Intel Atom cores with a Mali GPUs:
> >>>> https://en.wikipedia.org/wiki/Rockchip#Tablet_processors_with_integrated_modem
> >>>>
> >>>> So you can get rid of this whole line at all, meaning you don't even need
> >>>> the "depends on ARM || ARM64 || COMPILE_TEST" you have in your gitlab repo.
> >>>>
> >>>> Cheers,
> >>>> Andre.
> >>>>
> >>>>>
> >>>>> --
> >>>>> Best regards,
> >>>>> Marek Vasut
> >>>>> _______________________________________________
> >>>>> dri-devel mailing list
> >>>>> dri-devel at lists.freedesktop.org
> >>>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel
> >>
>