[Intel-gfx] [RFC libdrm] intel: Add support for softpin

[Daniel Vetter]

On Mon, Dec 14, 2015 at 08:41:05AM +0000, Song, Ruiling wrote:
> 
> 
> > -----Original Message-----
> > From: Daniel Vetter [mailto:daniel.vetter at ffwll.ch] On Behalf Of Daniel
> > Vetter
> > Sent: Monday, December 14, 2015 4:28 PM
> > To: Song, Ruiling <ruiling.song at intel.com>
> > Cc: krh at bitplanet.net; Winiarski, Michal <michal.winiarski at intel.com>;
> > mesa-dev at lists.freedesktop.org; intel-gfx at lists.freedesktop.org; Ben
> > Widawsky <ben at bwidawsk.net>; dri-devel at lists.freedesktop.org
> > Subject: Re: [Intel-gfx] [RFC libdrm] intel: Add support for softpin
> > 
> > On Mon, Dec 14, 2015 at 07:24:29AM +0000, Song, Ruiling wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: hoegsberg at gmail.com [mailto:hoegsberg at gmail.com] On Behalf
> > Of
> > > > Kristian H?gsberg
> > > > Sent: Monday, December 14, 2015 1:34 PM
> > > > To: Song, Ruiling <ruiling.song at intel.com>
> > > > Cc: Winiarski, Michal <michal.winiarski at intel.com>; intel-
> > > > gfx at lists.freedesktop.org; mesa-dev at lists.freedesktop.org; Ben
> > Widawsky
> > > > <ben at bwidawsk.net>; dri-devel at lists.freedesktop.org
> > > > Subject: Re: [Intel-gfx] [RFC libdrm] intel: Add support for softpin
> > > >
> > > > On Sun, Dec 13, 2015 at 7:17 PM, Song, Ruiling <ruiling.song at intel.com>
> > > > wrote:
> > > > >> -----Original Message-----
> > > > >> From: Intel-gfx [mailto:intel-gfx-bounces at lists.freedesktop.org] On
> > > > Behalf
> > > > >> Of Micha? Winiarski
> > > > >> Sent: Wednesday, September 9, 2015 10:07 PM
> > > > >> To: intel-gfx at lists.freedesktop.org
> > > > >> Cc: Ben Widawsky <ben at bwidawsk.net>; dri-
> > > > devel at lists.freedesktop.org;
> > > > >> mesa-dev at lists.freedesktop.org
> > > > >> Subject: [Intel-gfx] [RFC libdrm] intel: Add support for softpin
> > > > >>
> > > > >> Softpin allows userspace to take greater control of GPU virtual address
> > > > >> space and eliminates the need of relocations. It can also be used to
> > > > >> mirror addresses between GPU and CPU (shared virtual memory).
> > > > >> Calls to drm_intel_bo_emit_reloc are still required to build the list of
> > > > >> drm_i915_gem_exec_objects at exec time, but no entries in relocs are
> > > > >> created. Self-relocs don't make any sense for softpinned objects and
> > can
> > > > >> indicate a programming errors, thus are forbidden. Softpinned objects
> > > > >> are marked by asterisk in debug dumps.
> > > > >>
> > > > >> Cc: Thomas Daniel <thomas.daniel at intel.com>
> > > > >> Cc: Kristian Høgsberg <krh at bitplanet.net>
> > > > >> Cc: Zou Nanhai <nanhai.zou at intel.com>
> > > > >> Cc: Michel Thierry <michel.thierry at intel.com>
> > > > >> Cc: Ben Widawsky <ben at bwidawsk.net>
> > > > >> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > > > >> Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
> > > > >> ---
> > > > >>  include/drm/i915_drm.h    |   4 +-
> > > > >>  intel/intel_bufmgr.c      |   9 +++
> > > > >>  intel/intel_bufmgr.h      |   1 +
> > > > >>  intel/intel_bufmgr_gem.c  | 176
> > > > >> ++++++++++++++++++++++++++++++++++++++++------
> > > > >>  intel/intel_bufmgr_priv.h |   7 ++
> > > > >>  5 files changed, 173 insertions(+), 24 deletions(-)
> > > > >
> > > > > Will anybody help to push the patch to libdrm? Beignet highly depend
> > on
> > > > this to implement ocl2.0 svm.
> > > >
> > > > Is the kernel patch upstream?
> > >
> > > Yes, the kernel patch already merged, see:
> > > http://cgit.freedesktop.org/drm-
> > intel/commit/?id=506a8e87d8d2746b9e9d2433503fe237c54e4750
> > >
> > > I find below line of code in libdrm does not match the kernel version. The
> > kernel patch defined as:
> > > "#define EXEC_OBJECT_PINNED (1<<4)", but this patch defined it as (1<<3).
> > 
> > Please always regenerate the entire headers from the kernel sources using
> > 
> > $ make headers_install
> > 
> > Then copy the headers from the kernel's usr/include/drm to libdrm. Never
> > patch i915_drm.h manually.
> 
> Thanks for the info. But the problem is libdrm still tracks such kind of header files.
> Should this kind of header file be removed from libdrm? Or any document in libdrm to make this explicit?

All other kernel headers are extracted from the kernel directly, but
generally those packages only get update when a new kernel comes out.
Usually it's called linux-headers or similar. And only updating headers
when the release is out is _way_ too slow for drm/gfx. That's why we have
drm headers in libdrm.

But yeah we should document this, maybe even script it. Perhaps even just
upgrade headers automatically as soon as the upstream drm-next branch
changes.
-Daniel

> 
> Thanks!
> Ruiling
>  
> > Thanks, Daniel
> > 
> > >
> > > Hello Michal,
> > >
> > > Could you help to rebase the patch against:
> > > [Intel-gfx] [PATCH libdrm v4 0/2] 48-bit virtual address support in	i915
> > > I think we need both 48bit & softpin in libdrm.
> > >
> > > diff --git a/include/drm/i915_drm.h b/include/drm/i915_drm.h
> > > index ded43b1..2b99fc6 100644
> > > --- a/include/drm/i915_drm.h
> > > +++ b/include/drm/i915_drm.h
> > > @@ -350,6 +350,7 @@ typedef struct drm_i915_irq_wait {
> > >  #define I915_PARAM_REVISION              32
> > >  #define I915_PARAM_SUBSLICE_TOTAL	 33
> > >  #define I915_PARAM_EU_TOTAL		 34
> > > +#define I915_PARAM_HAS_EXEC_SOFTPIN	 37
> > >
> > >  typedef struct drm_i915_getparam {
> > >  	int param;
> > > @@ -680,7 +681,8 @@ struct drm_i915_gem_exec_object2 {
> > >  #define EXEC_OBJECT_NEEDS_FENCE (1<<0)
> > >  #define EXEC_OBJECT_NEEDS_GTT	(1<<1)
> > >  #define EXEC_OBJECT_WRITE	(1<<2)
> > > -#define __EXEC_OBJECT_UNKNOWN_FLAGS -(EXEC_OBJECT_WRITE<<1)
> > > +#define EXEC_OBJECT_PINNED	(1<<3)
> > > +#define __EXEC_OBJECT_UNKNOWN_FLAGS -(EXEC_OBJECT_PINNED<<1)
> > >  	__u64 flags;
> > >
> > > _______________________________________________
> > > Intel-gfx mailing list
> > > Intel-gfx at lists.freedesktop.org
> > > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
> > 
> > --
> > Daniel Vetter
> > Software Engineer, Intel Corporation
> > http://blog.ffwll.ch

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch