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[v7,0/4] Introduce pcim_alloc_irq_vectors()

Message ID 20210607153916.1021016-1-zhengdejin5@gmail.com
Headers show
Series Introduce pcim_alloc_irq_vectors() | expand

Message

Dejin Zheng June 7, 2021, 3:39 p.m. UTC
Introduce pcim_alloc_irq_vectors(), a device-managed version of
pci_alloc_irq_vectors(), In some i2c drivers, If pcim_enable_device()
has been called before, then pci_alloc_irq_vectors() is actually a
device-managed function. It is used as a device-managed function, So
replace it with pcim_alloc_irq_vectors().

Changelog
---------
v6 -> v7:
	- rebase to PCI next branch
	- add a stub for pci_is_managed() when disable PCI for
	  fix build error in sparc architecture.
v5 -> v6:
	- rebase to 5.13-rc4
v4 -> v5:
	- Remove the check of enable device in pcim_alloc_irq_vectors()
	  and make it as a static line function.
	- Modify the subject name in patch 3 and patch 4.
v3 -> v4:
	- add some commit comments for patch 3
v2 -> v3:
	- Add some commit comments for replace some codes in
	  pcim_release() by pci_free_irq_vectors().
	- Simplify the error handling path in i2c designware
	  driver.
v1 -> v2:
	- Use pci_free_irq_vectors() to replace some code in
	  pcim_release().
	- Modify some commit messages.

Dejin Zheng (4):
  PCI: Introduce pcim_alloc_irq_vectors()
  Documentation: devres: Add pcim_alloc_irq_vectors()
  i2c: designware: Use pcim_alloc_irq_vectors() to allocate IRQ vectors
  i2c: thunderx: Use pcim_alloc_irq_vectors() to allocate IRQ vectors

 .../driver-api/driver-model/devres.rst        |  1 +
 drivers/i2c/busses/i2c-designware-pcidrv.c    | 15 +++--------
 drivers/i2c/busses/i2c-thunderx-pcidrv.c      |  2 +-
 drivers/pci/pci.c                             |  5 +---
 include/linux/pci.h                           | 25 +++++++++++++++++++
 5 files changed, 32 insertions(+), 16 deletions(-)

Comments

Dejin Zheng June 8, 2021, 2:20 p.m. UTC | #1
On Mon, Jun 07, 2021 at 07:12:34PM +0300, Andy Shevchenko wrote:
> On Mon, Jun 07, 2021 at 11:39:13PM +0800, Dejin Zheng wrote:

> > Introduce pcim_alloc_irq_vectors(), a device-managed version of

> > pci_alloc_irq_vectors(). Introducing this function can simplify

> > the error handling path in many drivers.

> > 

> > And use pci_free_irq_vectors() to replace some code in pcim_release(),

> > they are equivalent, and no functional change. It is more explicit

> > that pcim_alloc_irq_vectors() is a device-managed function.

> 

> ...

> 

> > When CONFIG_PCI=n, there is no stub for pci_is_managed(), but

> > pcim_alloc_irq_vectors() will use it, so add one like other similar stubs.

> > Otherwise there can be build errors, as here by kernel test robot

> > reported:

> > include/linux/pci.h: In function 'pcim_alloc_irq_vectors':

> > >> include/linux/pci.h:1847:7: error: implicit declaration of function 'pci_is_managed' [-Werror=implicit-function-declaration]

> >     1847 |  if (!pci_is_managed(dev))

> >          |       ^~~~~~~~~~~~~~

> 

> This is rather changelog related material. No need to pollute commit message

> with this.

>

Okey.

> ...

> 

> > Reported-by: kernel test robot <lkp@intel.com>

> 

> It's new functionality. Why this tag is here?

> Use comments (similar location than changelog) to give a credit if you wish.

>

Got it, Thanks!

> > Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> > Reviewed-by: Robert Richter <rric@kernel.org>

> > Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

> > Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> > Signed-off-by: Dejin Zheng <zhengdejin5@gmail.com>

> > ---

> > v6 -> v7:

> > 	- rebase to PCI next branch

> > 	- add a stub for pci_is_managed() when disable PCI for

> > 	  fix build error in sparc architecture.

> > v5 -> v6:

> > 	- rebase to 5.13-rc4

> > v4 -> v5:

> > 	- Remove the check of enable device in pcim_alloc_irq_vectors()

> > 	  and make it as a static line function.

> > v3 -> v4:

> > 	- No change

> > v2 -> v3:

> > 	- Add some commit comments for replace some codes in

> > 	  pcim_release() by pci_free_irq_vectors().

> > v1 -> v2:

> > 	- Use pci_free_irq_vectors() to replace some code in

> > 	  pcim_release().

> > 	- Modify some commit messages.

> > 

> >  drivers/pci/pci.c   |  5 +----

> >  include/linux/pci.h | 25 +++++++++++++++++++++++++

> >  2 files changed, 26 insertions(+), 4 deletions(-)

> > 

> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c

> > index 452351025a09..e3b3fc59bd35 100644

> > --- a/drivers/pci/pci.c

> > +++ b/drivers/pci/pci.c

> > @@ -1989,10 +1989,7 @@ static void pcim_release(struct device *gendev, void *res)

> >  	struct pci_devres *this = res;

> >  	int i;

> >  

> > -	if (dev->msi_enabled)

> > -		pci_disable_msi(dev);

> > -	if (dev->msix_enabled)

> > -		pci_disable_msix(dev);

> > +	pci_free_irq_vectors(dev);

> >  

> >  	for (i = 0; i < DEVICE_COUNT_RESOURCE; i++)

> >  		if (this->region_mask & (1 << i))

> > diff --git a/include/linux/pci.h b/include/linux/pci.h

> > index c20211e59a57..5783262c4643 100644

> > --- a/include/linux/pci.h

> > +++ b/include/linux/pci.h

> > @@ -1730,6 +1730,7 @@ static inline struct pci_dev *pci_get_class(unsigned int class,

> >  

> >  static inline void pci_set_master(struct pci_dev *dev) { }

> >  static inline int pci_enable_device(struct pci_dev *dev) { return -EIO; }

> > +static inline int pci_is_managed(struct pci_dev *pdev) { return 0; }

> >  static inline void pci_disable_device(struct pci_dev *dev) { }

> >  static inline int pcim_enable_device(struct pci_dev *pdev) { return -EIO; }

> >  static inline int pci_assign_resource(struct pci_dev *dev, int i)

> > @@ -1825,6 +1826,30 @@ pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,

> >  					      NULL);

> >  }

> >  

> > +/**

> > + * pcim_alloc_irq_vectors - a device-managed pci_alloc_irq_vectors()

> > + * @dev:		PCI device to operate on

> > + * @min_vecs:		minimum number of vectors required (must be >= 1)

> > + * @max_vecs:		maximum (desired) number of vectors

> > + * @flags:		flags or quirks for the allocation

> > + *

> > + * Return the number of vectors allocated, (which might be smaller than

> > + * @max_vecs) if successful, or a negative error code on error. If less

> > + * than @min_vecs interrupt vectors are available for @dev the function

> > + * will fail with -ENOSPC.

> > + *

> > + * It depends on calling pcim_enable_device() to make IRQ resources

> > + * manageable.

> > + */

> > +static inline int

> > +pcim_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs,

> > +			unsigned int max_vecs, unsigned int flags)

> > +{

> > +	if (!pci_is_managed(dev))

> > +		return -EINVAL;

> > +	return pci_alloc_irq_vectors(dev, min_vecs, max_vecs, flags);

> > +}

> > +

> >  /* Include architecture-dependent settings and functions */

> >  

> >  #include <asm/pci.h>

> > -- 

> > 2.30.1

> > 

> 

> -- 

> With Best Regards,

> Andy Shevchenko

> 

>
Christoph Hellwig Feb. 24, 2022, 11:07 a.m. UTC | #2
On Mon, Jun 07, 2021 at 11:39:13PM +0800, Dejin Zheng wrote:
> Introduce pcim_alloc_irq_vectors(), a device-managed version of
> pci_alloc_irq_vectors(). Introducing this function can simplify
> the error handling path in many drivers.

How does it do that when it just is a trivial wrapper erroring out
for the unmanaged case?