On Mon, Mar 11, 2024 at 12:45:15PM +0100, Philipp Stanner wrote: > Gentle ping because the Merge Window opened 8-) Thanks; I'll look at this for v6.10. It's too late to add significant changes for the v6.9 merge window since it's already open. Bjorn > On Fri, 2024-03-01 at 12:29 +0100, Philipp Stanner wrote: > > This v4 now can (hopefully) be applied to linux-next, but not to > > mainline/master. > > > > 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 - Remove the comment advising to call (the outdated) pcim_intx() in 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 be encouraged to use the outdated pci_intx() mechanism.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 drivers won't use this outdated API (Andy, Myself) 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 | 1013 +++++++++++++++++++++-- > > -- > > drivers/pci/iomap.c | 18 + > > drivers/pci/pci.c | 123 ++- > > drivers/pci/pci.h | 21 +- > > include/linux/pci.h | 18 +- > > 6 files changed, 1001 insertions(+), 212 deletions(-) > > >
