From: Philipp Stanner <pstanner@redhat.com>
To: Hans de Goede <hdegoede@redhat.com>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>, Daniel Vetter <daniel@ffwll.ch>,
Bjorn Helgaas <bhelgaas@google.com>,
Sam Ravnborg <sam@ravnborg.org>,
dakr@redhat.com
Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
linux-pci@vger.kernel.org
Subject: Re: [PATCH v6 00/10] Make PCI's devres API more consistent
Date: Mon, 22 Apr 2024 09:23:03 +0200 [thread overview]
Message-ID: <7b8ffa914dfefcdb19bca9d80024fb8754b73459.camel@redhat.com> (raw)
In-Reply-To: <20240408084423.6697-1-pstanner@redhat.com>
Yo,
we know reached -rc5.
Is this fine for v6.10?
Regards,
P.
On Mon, 2024-04-08 at 10:44 +0200, Philipp Stanner wrote:
> Changes in v6:
> - Restructure the cleanup in pcim_iomap_regions_request_all() so
> that
> it doesn't trigger a (false positive) test robot warning. No
> behavior change intended. (Dan Carpenter)
>
> Changes in v5:
> - Add Hans's Reviewed-by to vboxvideo patch (Hans de Goede)
> - Remove stable-kernel from CC in vboxvideo patch (Hans de Goede)
>
> Changes in v4:
> - Rebase against linux-next
>
> Changes in v3:
> - Use the term "PCI devres API" at some forgotten places.
> - Fix more grammar errors in patch #3.
> - Remove the comment advising to call (the outdated) pcim_intx() in
> pci.c
> - Rename __pcim_request_region_range() flags-field "exclusive" to
> "req_flags", since this is what the int actually represents.
> - Remove the call to pcim_region_request() from patch #10. (Hans)
>
> Changes in v2:
> - Make commit head lines congruent with PCI's style (Bjorn)
> - Add missing error checks for devm_add_action(). (Andy)
> - Repair the "Returns: " marks for docu generation (Andy)
> - Initialize the addr_devres struct with memset(). (Andy)
> - Make pcim_intx() a PCI-internal function so that new drivers
> won't
> be encouraged to use the outdated pci_intx() mechanism.
> (Andy / Philipp)
> - Fix grammar and spelling (Bjorn)
> - Be more precise on why pcim_iomap_table() is problematic (Bjorn)
> - Provide the actual structs' and functions' names in the commit
> messages (Bjorn)
> - Remove redundant variable initializers (Andy)
> - Regroup PM bitfield members in struct pci_dev (Andy)
> - Make pcim_intx() visible only for the PCI subsystem so that
> new
> drivers won't use this outdated API (Andy, Myself)
> - Add a NOTE to pcim_iomap() to warn about this function being
> the onee
> xception that does just return NULL.
> - Consistently use the term "PCI devres API"; also in Patch #10
> (Bjorn)
>
>
> ¡Hola!
>
> PCI's devres API suffers several weaknesses:
>
> 1. There are functions prefixed with pcim_. Those are always managed
> counterparts to never-managed functions prefixed with pci_ – or so
> one
> would like to think. There are some apparently unmanaged functions
> (all region-request / release functions, and pci_intx()) which
> suddenly become managed once the user has initialized the device
> with
> pcim_enable_device() instead of pci_enable_device(). This
> "sometimes
> yes, sometimes no" nature of those functions is confusing and
> therefore bug-provoking. In fact, it has already caused a bug in
> DRM.
> The last patch in this series fixes that bug.
> 2. iomappings: Instead of giving each mapping its own callback, the
> existing API uses a statically allocated struct tracking one
> mapping
> per bar. This is not extensible. Especially, you can't create
> _ranged_ managed mappings that way, which many drivers want.
> 3. Managed request functions only exist as "plural versions" with a
> bit-mask as a parameter. That's quite over-engineered considering
> that each user only ever mapps one, maybe two bars.
>
> This series:
> - add a set of new "singular" devres functions that use devres the
> way
> its intended, with one callback per resource.
> - deprecates the existing iomap-table mechanism.
> - deprecates the hybrid nature of pci_ functions.
> - preserves backwards compatibility so that drivers using the
> existing
> API won't notice any changes.
> - adds documentation, especially some warning users about the
> complicated nature of PCI's devres.
>
>
> Note that this series is based on my "unify pci_iounmap"-series from
> a
> few weeks ago. [1]
>
> I tested this on a x86 VM with a simple pci test-device with two
> regions. Operates and reserves resources as intended on my system.
> Kasan and kmemleak didn't find any problems.
>
> I believe this series cleans the API up as much as possible without
> having to port all existing drivers to the new API. Especially, I
> think
> that this implementation is easy to extend if the need for new
> managed
> functions arises :)
>
> Greetings,
> P.
>
> Philipp Stanner (10):
> PCI: Add new set of devres functions
> PCI: Deprecate iomap-table functions
> PCI: Warn users about complicated devres nature
> PCI: Make devres region requests consistent
> PCI: Move dev-enabled status bit to struct pci_dev
> PCI: Move pinned status bit to struct pci_dev
> PCI: Give pcim_set_mwi() its own devres callback
> PCI: Give pci(m)_intx its own devres callback
> PCI: Remove legacy pcim_release()
> drm/vboxvideo: fix mapping leaks
>
> drivers/gpu/drm/vboxvideo/vbox_main.c | 20 +-
> drivers/pci/devres.c | 1011 +++++++++++++++++++++--
> --
> drivers/pci/iomap.c | 18 +
> drivers/pci/pci.c | 123 ++-
> drivers/pci/pci.h | 21 +-
> include/linux/pci.h | 18 +-
> 6 files changed, 999 insertions(+), 212 deletions(-)
>
next prev parent reply other threads:[~2024-04-22 7:23 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-08 8:44 [PATCH v6 00/10] Make PCI's devres API more consistent Philipp Stanner
2024-04-08 8:44 ` [PATCH v6 01/10] PCI: Add new set of devres functions Philipp Stanner
2024-04-08 8:44 ` [PATCH v6 02/10] PCI: Deprecate iomap-table functions Philipp Stanner
2024-04-08 8:44 ` [PATCH v6 03/10] PCI: Warn users about complicated devres nature Philipp Stanner
2024-04-24 20:12 ` Bjorn Helgaas
2024-04-08 8:44 ` [PATCH v6 04/10] PCI: Make devres region requests consistent Philipp Stanner
2024-04-24 20:12 ` Bjorn Helgaas
2024-04-26 7:45 ` Philipp Stanner
2024-04-08 8:44 ` [PATCH v6 05/10] PCI: Move dev-enabled status bit to struct pci_dev Philipp Stanner
2024-04-08 8:44 ` [PATCH v6 06/10] PCI: Move pinned " Philipp Stanner
2024-04-08 8:44 ` [PATCH v6 07/10] PCI: Give pcim_set_mwi() its own devres callback Philipp Stanner
2024-04-08 8:44 ` [PATCH v6 08/10] PCI: Give pci(m)_intx " Philipp Stanner
2024-04-08 8:44 ` [PATCH v6 09/10] PCI: Remove legacy pcim_release() Philipp Stanner
2024-04-08 8:44 ` [PATCH v6 10/10] drm/vboxvideo: fix mapping leaks Philipp Stanner
2024-04-22 7:23 ` Philipp Stanner [this message]
2024-04-24 20:12 ` [PATCH v6 00/10] Make PCI's devres API more consistent Bjorn Helgaas
2024-04-26 8:07 ` Philipp Stanner
2024-04-26 22:01 ` Bjorn Helgaas
2024-05-07 8:11 ` Philipp Stanner
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