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- Remove the comment advising to call (the outdated) pcim_intx() in pci.c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(-)
--
2.45.0
