LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Eric Anholt <eric@anholt.net>
To: Rob Herring <robh@kernel.org>, Daniel Vetter <daniel@ffwll.ch>
Cc: dri-devel <dri-devel@lists.freedesktop.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Linux ARM <linux-arm-kernel@lists.infradead.org>,
	Will Deacon <will.deacon@arm.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Joerg Roedel <joro@8bytes.org>,
	"list\@263.net\:IOMMU DRIVERS
	\<iommu\@lists.linux-foundation.org\>\,
	Joerg Roedel \<joro\@8bytes.org\>\," 
	<iommu@lists.linux-foundation.org>,
	Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
	Maxime Ripard <maxime.ripard@bootlin.com>,
	Sean Paul <sean@poorly.run>, David Airlie <airlied@linux.ie>,
	Alyssa Rosenzweig <alyssa@rosenzweig.io>,
	Lyude Paul <lyude@redhat.com>,
	Neil Armstrong <narmstrong@baylibre.com>
Subject: Re: [PATCH v2 2/3] drm: Add a drm_gem_objects_lookup helper
Date: Mon, 01 Apr 2019 11:22:14 -0700
Message-ID: <87sgv14mcp.fsf@anholt.net> (raw)
In-Reply-To: <CAL_JsqJ4uppXc_Sti67z0ZBJ4sw1RPgNHCg6usqpUmbQcGQmpQ@mail.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 2508 bytes --]

Rob Herring <robh@kernel.org> writes:

> On Mon, Apr 1, 2019 at 8:07 AM Daniel Vetter <daniel@ffwll.ch> wrote:
>>
>> On Mon, Apr 1, 2019 at 9:47 AM Rob Herring <robh@kernel.org> wrote:
>> >
>> > Similar to the single handle drm_gem_object_lookup(),
>> > drm_gem_objects_lookup() takes an array of handles and returns an array
>> > of GEM objects.
>> >
>> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
>> > Cc: Maxime Ripard <maxime.ripard@bootlin.com>
>> > Cc: Sean Paul <sean@poorly.run>
>> > Cc: David Airlie <airlied@linux.ie>
>> > Cc: Daniel Vetter <daniel@ffwll.ch>
>> > Signed-off-by: Rob Herring <robh@kernel.org>
>> > ---
>> >  drivers/gpu/drm/drm_gem.c | 46 +++++++++++++++++++++++++++++++--------
>> >  include/drm/drm_gem.h     |  2 ++
>> >  2 files changed, 39 insertions(+), 9 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
>> > index 388b3742e562..5c9bff45e5e1 100644
>> > --- a/drivers/gpu/drm/drm_gem.c
>> > +++ b/drivers/gpu/drm/drm_gem.c
>> > @@ -663,6 +663,42 @@ void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
>> >  }
>> >  EXPORT_SYMBOL(drm_gem_put_pages);
>> >
>> > +/**
>> > + * drm_gem_objects_lookup - look up GEM objects from an array of handles
>> > + * @filp: DRM file private date
>> > + * @handle: pointer to array of userspace handle
>> > + * @count: size of handle array
>> > + * @objs: pointer to array of drm_gem_object pointers
>> > + *
>> > + * Returns:
>> > + *
>> > + * @objs filled in with GEM object pointers. -ENOENT is returned on a lookup
>> > + * failure. 0 is returned on success.
>>
>> Bonus points for adding references between the array and normal lookup
>> functions to guide people around. Also a comment that the buffers need
>> to be released with drm_gem_object_put().
>>
>> > + */
>> > +int drm_gem_objects_lookup(struct drm_file *filp, u32 *handle, int count,
>> > +                          struct drm_gem_object **objs)
>>
>> With a pointer to a pointer I'd expect this function to do the
>> allocation, but it doesn't. Normal pointer is enough to pass an array.
>> Also maybe make the handle pointer
>> const, so it's clear that it's an input parameter.
>
> I thought about doing the allocation here, but then I couldn't
> implement the single drm_gem_object_lookup() using this function.
> Maybe I can refactor in 3 functions making this one a static function.

FWIW, I was thinking for v3d that I'd probably add a helper that took in
the user's pointer to handles :)

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 832 bytes --]

  reply index

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-01  7:47 [PATCH v2 0/3] Initial Panfrost driver Rob Herring
2019-04-01  7:47 ` [PATCH v3 1/3] iommu: io-pgtable: Add ARM Mali midgard MMU page table format Rob Herring
2019-04-01 19:11   ` Robin Murphy
2019-04-05 10:02     ` Robin Murphy
2019-04-11 13:15     ` Joerg Roedel
2019-04-05  9:42   ` Steven Price
2019-04-05  9:51     ` Robin Murphy
2019-04-05 10:36       ` Steven Price
2019-04-08  8:56         ` Steven Price
2019-04-01  7:47 ` [PATCH v2 2/3] drm: Add a drm_gem_objects_lookup helper Rob Herring
2019-04-01 13:06   ` Daniel Vetter
2019-04-01 13:48     ` Chris Wilson
2019-04-01 15:43       ` Eric Anholt
2019-04-08 20:09         ` Rob Herring
2019-04-09 16:55           ` Eric Anholt
2019-04-01 16:59     ` Rob Herring
2019-04-01 18:22       ` Eric Anholt [this message]
2019-04-01  7:47 ` [PATCH v2 3/3] drm/panfrost: Add initial panfrost driver Rob Herring
2019-04-01  8:24   ` Neil Armstrong
2019-04-01 19:17     ` Robin Murphy
2019-04-01 16:02   ` Eric Anholt
2019-04-01 19:12   ` Robin Murphy
2019-04-02  0:33     ` Alyssa Rosenzweig
2019-04-02 11:23       ` Robin Murphy
2019-04-03  4:57     ` Rob Herring
2019-04-05 12:57       ` Robin Murphy
2019-04-05 12:30   ` Steven Price
2019-04-05 16:16     ` Alyssa Rosenzweig
2019-04-05 16:42       ` Steven Price
2019-04-05 16:53         ` Alyssa Rosenzweig
2019-04-15  9:18         ` Daniel Vetter
2019-04-15  9:30           ` Steven Price
2019-04-16  7:51             ` Daniel Vetter
2019-04-08 21:04     ` Rob Herring
2019-04-09 15:56       ` Tomeu Vizoso
2019-04-09 16:15         ` Rob Herring
2019-04-10 10:28           ` Steven Price
2019-04-10 10:19       ` Steven Price
2019-04-10 11:50         ` Tomeu Vizoso
2019-04-01 15:05 ` [PATCH v2 0/3] Initial Panfrost driver Alyssa Rosenzweig

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87sgv14mcp.fsf@anholt.net \
    --to=eric@anholt.net \
    --cc=airlied@linux.ie \
    --cc=alyssa@rosenzweig.io \
    --cc=daniel@ffwll.ch \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=iommu@lists.linux-foundation.org \
    --cc=joro@8bytes.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=lyude@redhat.com \
    --cc=maarten.lankhorst@linux.intel.com \
    --cc=maxime.ripard@bootlin.com \
    --cc=narmstrong@baylibre.com \
    --cc=robh@kernel.org \
    --cc=robin.murphy@arm.com \
    --cc=sean@poorly.run \
    --cc=will.deacon@arm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org linux-kernel@archiver.kernel.org
	public-inbox-index lkml


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/ public-inbox