| Message ID | 20241015185124.64726-14-pstanner@redhat.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Remove implicit devres from pci_intx() | expand |
On Tue, 15 Oct 2024 20:51:23 +0200 Philipp Stanner <pstanner@redhat.com> wrote: > pci_intx() and its managed counterpart pcim_intx() only exist for older > drivers which have not been ported yet for various reasons. Future > drivers should preferably use pci_alloc_irq_vectors(). > > Mark pci_intx() and pcim_intx() as deprecated and encourage usage of > pci_alloc_irq_vectors() in its place. I don't really understand this. As we've discussed previously pci_alloc_irq_vectors() is, unsurprisingly, for allocating PCI IRQ vectors while pci_intx() is for manipulating the INTx disable bit on PCI devices. The latter is a generic mechanism for preventing PCI devices from generating INTx, regardless of whether there's a vector allocated for it. How does the former replace the latter and why do we feel the need to deprecate the latter? It feels like this fits some narrow narrative and makes all users of these now deprecated functions second class citizens. Why? At it's root these are simply providing mask and set or mask and clear register bit operations. Thanks, Alex > Signed-off-by: Philipp Stanner <pstanner@redhat.com> > --- > drivers/pci/devres.c | 5 ++++- > drivers/pci/pci.c | 5 ++++- > 2 files changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c > index 6f8f712fe34e..4c76fc063104 100644 > --- a/drivers/pci/devres.c > +++ b/drivers/pci/devres.c > @@ -435,7 +435,7 @@ static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev) > } > > /** > - * pcim_intx - managed pci_intx() > + * pcim_intx - managed pci_intx() (DEPRECATED) > * @pdev: the PCI device to operate on > * @enable: boolean: whether to enable or disable PCI INTx > * > @@ -443,6 +443,9 @@ static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev) > * > * Enable/disable PCI INTx for device @pdev. > * Restore the original state on driver detach. > + * > + * This function is DEPRECATED. Do not use it in new code. > + * Use pci_alloc_irq_vectors() instead (there is no managed version, currently). > */ > int pcim_intx(struct pci_dev *pdev, int enable) > { > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 7ce1d0e3a1d5..dc69e23b8982 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4477,11 +4477,14 @@ void pci_disable_parity(struct pci_dev *dev) > } > > /** > - * pci_intx - enables/disables PCI INTx for device dev > + * pci_intx - enables/disables PCI INTx for device dev (DEPRECATED) > * @pdev: the PCI device to operate on > * @enable: boolean: whether to enable or disable PCI INTx > * > * Enables/disables PCI INTx for device @pdev > + * > + * This function is DEPRECATED. Do not use it in new code. > + * Use pci_alloc_irq_vectors() instead. > */ > void pci_intx(struct pci_dev *pdev, int enable) > {
On Tue, Oct 15, 2024 at 08:51:23PM +0200, Philipp Stanner wrote: > pci_intx() and its managed counterpart pcim_intx() only exist for older > drivers which have not been ported yet for various reasons. Future > drivers should preferably use pci_alloc_irq_vectors(). > > Mark pci_intx() and pcim_intx() as deprecated and encourage usage of > pci_alloc_irq_vectors() in its place. No one is going to notice these comments, so please, if this really does need to be removed, just remove it from all callers and delete the function from the tree. thanks, greg k-h
On Tue, 2024-10-15 at 13:53 -0600, Alex Williamson wrote: > On Tue, 15 Oct 2024 20:51:23 +0200 > Philipp Stanner <pstanner@redhat.com> wrote: > > > pci_intx() and its managed counterpart pcim_intx() only exist for > > older > > drivers which have not been ported yet for various reasons. Future > > drivers should preferably use pci_alloc_irq_vectors(). > > > > Mark pci_intx() and pcim_intx() as deprecated and encourage usage > > of > > pci_alloc_irq_vectors() in its place. > > I don't really understand this. As we've discussed previously > pci_alloc_irq_vectors() is, unsurprisingly, for allocating PCI IRQ > vectors while pci_intx() is for manipulating the INTx disable bit on > PCI devices. The latter is a generic mechanism for preventing PCI > devices from generating INTx, regardless of whether there's a vector > allocated for it. How does the former replace the latter and why do > we > feel the need to deprecate the latter? > > It feels like this fits some narrow narrative and makes all users of > these now deprecated functions second class citizens. Why? At it's > root these are simply providing mask and set or mask and clear > register > bit operations. Thanks, I got the feeling from the RFC discussion that that was basically the consensus: people should use pci_alloc_irq_vectors(). Or did I misunderstand Andy and Heiner? I'm perfectly happy with dropping this patch and continue offering pci{m}_intx() to users, since after removing that hybrid hazzard I don't see any harm in them anymore. P. > > Alex > > > Signed-off-by: Philipp Stanner <pstanner@redhat.com> > > --- > > drivers/pci/devres.c | 5 ++++- > > drivers/pci/pci.c | 5 ++++- > > 2 files changed, 8 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c > > index 6f8f712fe34e..4c76fc063104 100644 > > --- a/drivers/pci/devres.c > > +++ b/drivers/pci/devres.c > > @@ -435,7 +435,7 @@ static struct pcim_intx_devres > > *get_or_create_intx_devres(struct device *dev) > > } > > > > /** > > - * pcim_intx - managed pci_intx() > > + * pcim_intx - managed pci_intx() (DEPRECATED) > > * @pdev: the PCI device to operate on > > * @enable: boolean: whether to enable or disable PCI INTx > > * > > @@ -443,6 +443,9 @@ static struct pcim_intx_devres > > *get_or_create_intx_devres(struct device *dev) > > * > > * Enable/disable PCI INTx for device @pdev. > > * Restore the original state on driver detach. > > + * > > + * This function is DEPRECATED. Do not use it in new code. > > + * Use pci_alloc_irq_vectors() instead (there is no managed > > version, currently). > > */ > > int pcim_intx(struct pci_dev *pdev, int enable) > > { > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > index 7ce1d0e3a1d5..dc69e23b8982 100644 > > --- a/drivers/pci/pci.c > > +++ b/drivers/pci/pci.c > > @@ -4477,11 +4477,14 @@ void pci_disable_parity(struct pci_dev > > *dev) > > } > > > > /** > > - * pci_intx - enables/disables PCI INTx for device dev > > + * pci_intx - enables/disables PCI INTx for device dev > > (DEPRECATED) > > * @pdev: the PCI device to operate on > > * @enable: boolean: whether to enable or disable PCI INTx > > * > > * Enables/disables PCI INTx for device @pdev > > + * > > + * This function is DEPRECATED. Do not use it in new code. > > + * Use pci_alloc_irq_vectors() instead. > > */ > > void pci_intx(struct pci_dev *pdev, int enable) > > { >
On 16.10.2024 08:57, Philipp Stanner wrote: > On Tue, 2024-10-15 at 13:53 -0600, Alex Williamson wrote: >> On Tue, 15 Oct 2024 20:51:23 +0200 >> Philipp Stanner <pstanner@redhat.com> wrote: >> >>> pci_intx() and its managed counterpart pcim_intx() only exist for >>> older >>> drivers which have not been ported yet for various reasons. Future >>> drivers should preferably use pci_alloc_irq_vectors(). >>> >>> Mark pci_intx() and pcim_intx() as deprecated and encourage usage >>> of >>> pci_alloc_irq_vectors() in its place. >> >> I don't really understand this. As we've discussed previously >> pci_alloc_irq_vectors() is, unsurprisingly, for allocating PCI IRQ >> vectors while pci_intx() is for manipulating the INTx disable bit on >> PCI devices. The latter is a generic mechanism for preventing PCI >> devices from generating INTx, regardless of whether there's a vector >> allocated for it. How does the former replace the latter and why do >> we >> feel the need to deprecate the latter? >> >> It feels like this fits some narrow narrative and makes all users of >> these now deprecated functions second class citizens. Why? At it's >> root these are simply providing mask and set or mask and clear >> register >> bit operations. Thanks, > > I got the feeling from the RFC discussion that that was basically the > consensus: people should use pci_alloc_irq_vectors(). Or did I > misunderstand Andy and Heiner? > I think there are two different use cases for pci_intx(). At first there are several drivers where the direct usage of pci_intx() can be eliminated by switching to the pci_alloc_irq_vectors() API. And then there's usage of pci_intx() in drivers/vfio/pci/vfio_pci_intrs.c drivers/xen/xen-pciback/conf_space_header.c There we have to keep the (AFAICS unmanaged) pci_intx() calls. > I'm perfectly happy with dropping this patch and continue offering > pci{m}_intx() to users, since after removing that hybrid hazzard I > don't see any harm in them anymore. > > > P. > >> >> Alex >> >>> Signed-off-by: Philipp Stanner <pstanner@redhat.com> >>> --- >>> drivers/pci/devres.c | 5 ++++- >>> drivers/pci/pci.c | 5 ++++- >>> 2 files changed, 8 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c >>> index 6f8f712fe34e..4c76fc063104 100644 >>> --- a/drivers/pci/devres.c >>> +++ b/drivers/pci/devres.c >>> @@ -435,7 +435,7 @@ static struct pcim_intx_devres >>> *get_or_create_intx_devres(struct device *dev) >>> } >>> >>> /** >>> - * pcim_intx - managed pci_intx() >>> + * pcim_intx - managed pci_intx() (DEPRECATED) >>> * @pdev: the PCI device to operate on >>> * @enable: boolean: whether to enable or disable PCI INTx >>> * >>> @@ -443,6 +443,9 @@ static struct pcim_intx_devres >>> *get_or_create_intx_devres(struct device *dev) >>> * >>> * Enable/disable PCI INTx for device @pdev. >>> * Restore the original state on driver detach. >>> + * >>> + * This function is DEPRECATED. Do not use it in new code. >>> + * Use pci_alloc_irq_vectors() instead (there is no managed >>> version, currently). >>> */ >>> int pcim_intx(struct pci_dev *pdev, int enable) >>> { >>> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c >>> index 7ce1d0e3a1d5..dc69e23b8982 100644 >>> --- a/drivers/pci/pci.c >>> +++ b/drivers/pci/pci.c >>> @@ -4477,11 +4477,14 @@ void pci_disable_parity(struct pci_dev >>> *dev) >>> } >>> >>> /** >>> - * pci_intx - enables/disables PCI INTx for device dev >>> + * pci_intx - enables/disables PCI INTx for device dev >>> (DEPRECATED) >>> * @pdev: the PCI device to operate on >>> * @enable: boolean: whether to enable or disable PCI INTx >>> * >>> * Enables/disables PCI INTx for device @pdev >>> + * >>> + * This function is DEPRECATED. Do not use it in new code. >>> + * Use pci_alloc_irq_vectors() instead. >>> */ >>> void pci_intx(struct pci_dev *pdev, int enable) >>> { >> > >
On Wed, 2024-10-16 at 10:43 +0200, Heiner Kallweit wrote: > On 16.10.2024 08:57, Philipp Stanner wrote: > > On Tue, 2024-10-15 at 13:53 -0600, Alex Williamson wrote: > > > On Tue, 15 Oct 2024 20:51:23 +0200 > > > Philipp Stanner <pstanner@redhat.com> wrote: > > > > > > > pci_intx() and its managed counterpart pcim_intx() only exist > > > > for > > > > older > > > > drivers which have not been ported yet for various reasons. > > > > Future > > > > drivers should preferably use pci_alloc_irq_vectors(). > > > > > > > > Mark pci_intx() and pcim_intx() as deprecated and encourage > > > > usage > > > > of > > > > pci_alloc_irq_vectors() in its place. > > > > > > I don't really understand this. As we've discussed previously > > > pci_alloc_irq_vectors() is, unsurprisingly, for allocating PCI > > > IRQ > > > vectors while pci_intx() is for manipulating the INTx disable bit > > > on > > > PCI devices. The latter is a generic mechanism for preventing > > > PCI > > > devices from generating INTx, regardless of whether there's a > > > vector > > > allocated for it. How does the former replace the latter and why > > > do > > > we > > > feel the need to deprecate the latter? > > > > > > It feels like this fits some narrow narrative and makes all users > > > of > > > these now deprecated functions second class citizens. Why? At > > > it's > > > root these are simply providing mask and set or mask and clear > > > register > > > bit operations. Thanks, > > > > I got the feeling from the RFC discussion that that was basically > > the > > consensus: people should use pci_alloc_irq_vectors(). Or did I > > misunderstand Andy and Heiner? > > > I think there are two different use cases for pci_intx(). > At first there are several drivers where the direct usage of > pci_intx() > can be eliminated by switching to the pci_alloc_irq_vectors() API. > > And then there's usage of pci_intx() in > drivers/vfio/pci/vfio_pci_intrs.c > drivers/xen/xen-pciback/conf_space_header.c > There we have to keep the (AFAICS unmanaged) pci_intx() calls. There is also the usage within PCI itself, in MSI. Patch №8 touches that. It's why I think this series should land before anyone should port direct pci_intx() users to the irq vectors function, because the latter also uses pci_intx() and its own devres, which sounds explosive to me. P. > > > I'm perfectly happy with dropping this patch and continue offering > > pci{m}_intx() to users, since after removing that hybrid hazzard I > > don't see any harm in them anymore. > > > > > > P. > > > > > > > > Alex > > > > > > > Signed-off-by: Philipp Stanner <pstanner@redhat.com> > > > > --- > > > > drivers/pci/devres.c | 5 ++++- > > > > drivers/pci/pci.c | 5 ++++- > > > > 2 files changed, 8 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c > > > > index 6f8f712fe34e..4c76fc063104 100644 > > > > --- a/drivers/pci/devres.c > > > > +++ b/drivers/pci/devres.c > > > > @@ -435,7 +435,7 @@ static struct pcim_intx_devres > > > > *get_or_create_intx_devres(struct device *dev) > > > > } > > > > > > > > /** > > > > - * pcim_intx - managed pci_intx() > > > > + * pcim_intx - managed pci_intx() (DEPRECATED) > > > > * @pdev: the PCI device to operate on > > > > * @enable: boolean: whether to enable or disable PCI INTx > > > > * > > > > @@ -443,6 +443,9 @@ static struct pcim_intx_devres > > > > *get_or_create_intx_devres(struct device *dev) > > > > * > > > > * Enable/disable PCI INTx for device @pdev. > > > > * Restore the original state on driver detach. > > > > + * > > > > + * This function is DEPRECATED. Do not use it in new code. > > > > + * Use pci_alloc_irq_vectors() instead (there is no managed > > > > version, currently). > > > > */ > > > > int pcim_intx(struct pci_dev *pdev, int enable) > > > > { > > > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > > > index 7ce1d0e3a1d5..dc69e23b8982 100644 > > > > --- a/drivers/pci/pci.c > > > > +++ b/drivers/pci/pci.c > > > > @@ -4477,11 +4477,14 @@ void pci_disable_parity(struct pci_dev > > > > *dev) > > > > } > > > > > > > > /** > > > > - * pci_intx - enables/disables PCI INTx for device dev > > > > + * pci_intx - enables/disables PCI INTx for device dev > > > > (DEPRECATED) > > > > * @pdev: the PCI device to operate on > > > > * @enable: boolean: whether to enable or disable PCI INTx > > > > * > > > > * Enables/disables PCI INTx for device @pdev > > > > + * > > > > + * This function is DEPRECATED. Do not use it in new code. > > > > + * Use pci_alloc_irq_vectors() instead. > > > > */ > > > > void pci_intx(struct pci_dev *pdev, int enable) > > > > { > > > > > > > >
diff --git a/drivers/pci/devres.c b/drivers/pci/devres.c index 6f8f712fe34e..4c76fc063104 100644 --- a/drivers/pci/devres.c +++ b/drivers/pci/devres.c @@ -435,7 +435,7 @@ static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev) } /** - * pcim_intx - managed pci_intx() + * pcim_intx - managed pci_intx() (DEPRECATED) * @pdev: the PCI device to operate on * @enable: boolean: whether to enable or disable PCI INTx * @@ -443,6 +443,9 @@ static struct pcim_intx_devres *get_or_create_intx_devres(struct device *dev) * * Enable/disable PCI INTx for device @pdev. * Restore the original state on driver detach. + * + * This function is DEPRECATED. Do not use it in new code. + * Use pci_alloc_irq_vectors() instead (there is no managed version, currently). */ int pcim_intx(struct pci_dev *pdev, int enable) { diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 7ce1d0e3a1d5..dc69e23b8982 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4477,11 +4477,14 @@ void pci_disable_parity(struct pci_dev *dev) } /** - * pci_intx - enables/disables PCI INTx for device dev + * pci_intx - enables/disables PCI INTx for device dev (DEPRECATED) * @pdev: the PCI device to operate on * @enable: boolean: whether to enable or disable PCI INTx * * Enables/disables PCI INTx for device @pdev + * + * This function is DEPRECATED. Do not use it in new code. + * Use pci_alloc_irq_vectors() instead. */ void pci_intx(struct pci_dev *pdev, int enable) {
pci_intx() and its managed counterpart pcim_intx() only exist for older drivers which have not been ported yet for various reasons. Future drivers should preferably use pci_alloc_irq_vectors(). Mark pci_intx() and pcim_intx() as deprecated and encourage usage of pci_alloc_irq_vectors() in its place. Signed-off-by: Philipp Stanner <pstanner@redhat.com> --- drivers/pci/devres.c | 5 ++++- drivers/pci/pci.c | 5 ++++- 2 files changed, 8 insertions(+), 2 deletions(-)