Re: [PATCH v5 8/9] PCI: Define scoped based management functions

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Wed, 20 Dec 2023 16:17:35 -0800
Ira Weiny <ira.weiny@intel.com> wrote:

> Users of pci_dev_get() can benefit from a scoped based put.  Also,
> locking a PCI device is often done within a single scope.
> 
> Define a pci_dev_put() free function and a PCI device lock guard.  These
> will initially be used in new CXL event processing code but is defined
> in a separate patch for others to pickup and use/backport easier.
> 
> Cc: Bjorn Helgaas      <bhelgaas@google.com>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

With the extra text buried deep in the discussion LGTM.
I've not been that thorough on documenting my own similar cleanup.h
series, so might well steal some of that for the ones I have outstanding
for device_handle_put() and fwnode_handle_put() ;)

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> 
> ---
> Changes for v5:
> [Jonathan: New patch]
> ---
>  include/linux/pci.h | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 60ca768bc867..290d0a2651b2 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1170,6 +1170,7 @@ int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge);
>  u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp);
>  struct pci_dev *pci_dev_get(struct pci_dev *dev);
>  void pci_dev_put(struct pci_dev *dev);
> +DEFINE_FREE(pci_dev_put, struct pci_dev *, if (_T) pci_dev_put(_T))
>  void pci_remove_bus(struct pci_bus *b);
>  void pci_stop_and_remove_bus_device(struct pci_dev *dev);
>  void pci_stop_and_remove_bus_device_locked(struct pci_dev *dev);
> @@ -1871,6 +1872,7 @@ void pci_cfg_access_unlock(struct pci_dev *dev);
>  void pci_dev_lock(struct pci_dev *dev);
>  int pci_dev_trylock(struct pci_dev *dev);
>  void pci_dev_unlock(struct pci_dev *dev);
> +DEFINE_GUARD(pci_dev, struct pci_dev *, pci_dev_lock(_T), pci_dev_unlock(_T))
>  
>  /*
>   * PCI domain support.  Sometimes called PCI segment (eg by ACPI),
>