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[149.14.88.26]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3607509c883sm1510620f8f.29.2024.06.13.04.50.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 13 Jun 2024 04:50:44 -0700 (PDT) From: Philipp Stanner To: Hans de Goede , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Bjorn Helgaas , Sam Ravnborg , dakr@redhat.com Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Philipp Stanner Subject: [PATCH v9 00/13] Make PCI's devres API more consistent Date: Thu, 13 Jun 2024 13:50:13 +0200 Message-ID: <20240613115032.29098-1-pstanner@redhat.com> X-Mailer: git-send-email 2.45.0 MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Changes in v9: - Remove forgotten dead code ('enabled' bit in struct pci_dev) in patch No.8 ("Move pinned status bit...") - Rework patch No.3: - Change title from "Reimplement plural devres functions" to "Add partial-BAR devres support". - Drop excessive details about the general cleanup from the commit message. Only motivate why this patch's new infrastructure is necessary. - Fix some minor spelling issues (s/pci/PCI ...) Changes in v8: - Rebase the series on the already merged patches which were slightly modified by Bjorn Helgaas. - Reword the pci_intx() commit message so it clearly states it's about reworking pci_intx(). - Move the removal of find_pci_dr() from patch "Remove legacy pcim_release()" to patch "Give pci_intx() its own devres callback" since this later patch already removed all calls to that function. - In patch "Give pci_intx() its own devres callback": use pci_is_enabled() (and, thus, the enabled_cnt in struct pci_dev) instead of a separate enabled field. (Bjorn) Changes in v7: - Split the entire series in smaller, more atomic chunks / patches (Bjorn) - Remove functions (such as pcim_iomap_region_range()) that do not yet have a user (Bjorn) - Don't export interfaces publicly anymore, except for pcim_iomap_range(), needed by vboxvideo (Bjorn) - Mention the actual (vboxvideo) bug in "PCI: Warn users..." commit (Bjorn) - Drop docstring warnings on PCI-internal functions (Bjorn) - Rework docstring warnings - Fix spelling in a few places. Rewrapp paragraphs (Bjorn) 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 one exception 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 (13): PCI: Add and use devres helper for bit masks PCI: Add devres helpers for iomap table PCI: Add partial-BAR devres support PCI: Deprecate two surplus devres functions PCI: Make devres region requests consistent PCI: Warn users about complicated devres nature PCI: Remove enabled status bit from pci_devres PCI: Move pinned status bit to struct pci_dev PCI: Give pcim_set_mwi() its own devres callback PCI: Give pci_intx() its own devres callback PCI: Remove legacy pcim_release() PCI: Add pcim_iomap_range() drm/vboxvideo: fix mapping leaks drivers/gpu/drm/vboxvideo/vbox_main.c | 20 +- drivers/pci/devres.c | 903 +++++++++++++++++++++----- drivers/pci/iomap.c | 16 + drivers/pci/pci.c | 94 ++- drivers/pci/pci.h | 23 +- include/linux/pci.h | 5 +- 6 files changed, 858 insertions(+), 203 deletions(-)