diff mbox series

[RFC,31/32] usb: handle HAS_IOPORT dependencies

Message ID 20211227164317.4146918-32-schnelle@linux.ibm.com (mailing list archive)
State New, archived
Headers show
Series Kconfig: Introduce HAS_IOPORT and LEGACY_PCI options | expand

Commit Message

Niklas Schnelle Dec. 27, 2021, 4:43 p.m. UTC
In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
not being declared. We thus need to guard sections of code calling them
as alternative access methods with CONFIG_HAS_IOPORT checks. Similarly
drivers requiring these functions need to depend on HAS_IOPORT.

Co-developed-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
---
 drivers/usb/core/hcd-pci.c    |   3 +-
 drivers/usb/host/Kconfig      |   4 +-
 drivers/usb/host/pci-quirks.c | 127 ++++++++++++++++++----------------
 drivers/usb/host/pci-quirks.h |  33 ++++++---
 drivers/usb/host/uhci-hcd.c   |   2 +-
 drivers/usb/host/uhci-hcd.h   |  77 ++++++++++++++-------
 6 files changed, 148 insertions(+), 98 deletions(-)

Comments

Alan Stern Dec. 27, 2021, 8:36 p.m. UTC | #1
On Mon, Dec 27, 2021 at 05:43:16PM +0100, Niklas Schnelle wrote:
> In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> not being declared. We thus need to guard sections of code calling them
> as alternative access methods with CONFIG_HAS_IOPORT checks. Similarly
> drivers requiring these functions need to depend on HAS_IOPORT.

A few things in here can be improved.

> 
> Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Arnd Bergmann <arnd@kernel.org>
> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> ---
>  drivers/usb/core/hcd-pci.c    |   3 +-
>  drivers/usb/host/Kconfig      |   4 +-
>  drivers/usb/host/pci-quirks.c | 127 ++++++++++++++++++----------------
>  drivers/usb/host/pci-quirks.h |  33 ++++++---
>  drivers/usb/host/uhci-hcd.c   |   2 +-
>  drivers/usb/host/uhci-hcd.h   |  77 ++++++++++++++-------
>  6 files changed, 148 insertions(+), 98 deletions(-)

> diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
> index ef08d68b9714..bba320194027 100644
> --- a/drivers/usb/host/pci-quirks.c
> +++ b/drivers/usb/host/pci-quirks.c

> +#ifdef CONFIG_USB_PCI_AMD
> +#if IS_ENABLED(CONFIG_USB_UHCI_HCD) && defined(CONFIG_HAS_IOPORT)

In the original, the following code will be compiled even if
CONFIG_USB_UHCI_HCD is not enabled.  You shouldn't change that.

>  /*
>   * Make sure the controller is completely inactive, unable to
>   * generate interrupts or do DMA.

> @@ -1273,7 +1277,8 @@ static void quirk_usb_early_handoff(struct pci_dev *pdev)
>  			 "Can't enable PCI device, BIOS handoff failed.\n");
>  		return;
>  	}
> -	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
> +	if (IS_ENABLED(CONFIG_USB_UHCI_HCD) &&
> +	    pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
>  		quirk_usb_handoff_uhci(pdev);

Same idea here.

>  	else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
>  		quirk_usb_handoff_ohci(pdev);
> diff --git a/drivers/usb/host/pci-quirks.h b/drivers/usb/host/pci-quirks.h
> index e729de21fad7..42eb18be37af 100644
> --- a/drivers/usb/host/pci-quirks.h
> +++ b/drivers/usb/host/pci-quirks.h
> @@ -2,33 +2,50 @@
>  #ifndef __LINUX_USB_PCI_QUIRKS_H
>  #define __LINUX_USB_PCI_QUIRKS_H
>  
> -#ifdef CONFIG_USB_PCI
>  void uhci_reset_hc(struct pci_dev *pdev, unsigned long base);
>  int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base);
> -int usb_hcd_amd_remote_wakeup_quirk(struct pci_dev *pdev);
> +
> +struct pci_dev;

This can't be right; struct pci_dev is referred to three lines earlier.
You could move this up, but it may not be needed at all.

> diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
> index 8ae5ccd26753..8e30116b6fd2 100644
> --- a/drivers/usb/host/uhci-hcd.h
> +++ b/drivers/usb/host/uhci-hcd.h
> @@ -586,12 +586,14 @@ static inline int uhci_aspeed_reg(unsigned int reg)
>  
>  static inline u32 uhci_readl(const struct uhci_hcd *uhci, int reg)
>  {
> +#ifdef CONFIG_HAS_IOPORT
>  	if (uhci_has_pci_registers(uhci))
>  		return inl(uhci->io_addr + reg);
> -	else if (uhci_is_aspeed(uhci))
> +#endif

Instead of making all these changes (here and in the hunks below), you
can simply modify the definition of uhci_has_pci_registers() so that it
always gives 0 when CONFIG_HAS_IOPORT is N.

Alan Stern
Niklas Schnelle Dec. 31, 2021, 11:06 a.m. UTC | #2
On Mon, 2021-12-27 at 15:36 -0500, Alan Stern wrote:
> On Mon, Dec 27, 2021 at 05:43:16PM +0100, Niklas Schnelle wrote:
> > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > not being declared. We thus need to guard sections of code calling them
> > as alternative access methods with CONFIG_HAS_IOPORT checks. Similarly
> > drivers requiring these functions need to depend on HAS_IOPORT.
> 
> A few things in here can be improved.
> 
> > Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> > Signed-off-by: Arnd Bergmann <arnd@kernel.org>
> > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> > ---
> >  drivers/usb/core/hcd-pci.c    |   3 +-
> >  drivers/usb/host/Kconfig      |   4 +-
> >  drivers/usb/host/pci-quirks.c | 127 ++++++++++++++++++----------------
> >  drivers/usb/host/pci-quirks.h |  33 ++++++---
> >  drivers/usb/host/uhci-hcd.c   |   2 +-
> >  drivers/usb/host/uhci-hcd.h   |  77 ++++++++++++++-------
> >  6 files changed, 148 insertions(+), 98 deletions(-)
> > diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
> > index ef08d68b9714..bba320194027 100644
> > --- a/drivers/usb/host/pci-quirks.c
> > +++ b/drivers/usb/host/pci-quirks.c
> > +#ifdef CONFIG_USB_PCI_AMD
> > +#if IS_ENABLED(CONFIG_USB_UHCI_HCD) && defined(CONFIG_HAS_IOPORT)
> 
> In the original, the following code will be compiled even if
> CONFIG_USB_UHCI_HCD is not enabled.  You shouldn't change that.

If this was only '#ifdef CONFIG_HAS_IOPORT' we would leave
uhci_reset_hc() undeclared in the case where CONFIG_HAS_IOPORT is
unset. This function however is also called from uhci-pci.c. That on
the other hand is built only if CONFIG_USB_UHCI_HCD is set so if we
depend on both config options we can get rid of all calls and have the
functions undeclared.

> 
> >  /*
> >   * Make sure the controller is completely inactive, unable to
> >   * generate interrupts or do DMA.
> > @@ -1273,7 +1277,8 @@ static void quirk_usb_early_handoff(struct pci_dev *pdev)
> >  			 "Can't enable PCI device, BIOS handoff failed.\n");
> >  		return;
> >  	}
> > -	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
> > +	if (IS_ENABLED(CONFIG_USB_UHCI_HCD) &&
> > +	    pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
> >  		quirk_usb_handoff_uhci(pdev);
> 
> Same idea here.

Hmm, I'm not 100% sure if the IS_ENABLED(CONFIG_USB_UHCI_HCD) depends
on some compiler optimizations for it to be ok that
uhci_check_and_reset_hc() is not declared in the case where both
CONFIG_HAS_IOPORT and CONFIG_USB_UHCI_HCD are unset. Maybe that should
be a plain ifdef.

> 
> >  	else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
> >  		quirk_usb_handoff_ohci(pdev);
> > diff --git a/drivers/usb/host/pci-quirks.h b/drivers/usb/host/pci-quirks.h
> > index e729de21fad7..42eb18be37af 100644
> > --- a/drivers/usb/host/pci-quirks.h
> > +++ b/drivers/usb/host/pci-quirks.h
> > @@ -2,33 +2,50 @@
> >  #ifndef __LINUX_USB_PCI_QUIRKS_H
> >  #define __LINUX_USB_PCI_QUIRKS_H
> >  
> > -#ifdef CONFIG_USB_PCI
> >  void uhci_reset_hc(struct pci_dev *pdev, unsigned long base);
> >  int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base);
> > -int usb_hcd_amd_remote_wakeup_quirk(struct pci_dev *pdev);
> > +
> > +struct pci_dev;
> 
> This can't be right; struct pci_dev is referred to three lines earlier.
> You could move this up, but it may not be needed at all.

I agree.

> 
> > diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
> > index 8ae5ccd26753..8e30116b6fd2 100644
> > --- a/drivers/usb/host/uhci-hcd.h
> > +++ b/drivers/usb/host/uhci-hcd.h
> > @@ -586,12 +586,14 @@ static inline int uhci_aspeed_reg(unsigned int reg)
> >  
> >  static inline u32 uhci_readl(const struct uhci_hcd *uhci, int reg)
> >  {
> > +#ifdef CONFIG_HAS_IOPORT
> >  	if (uhci_has_pci_registers(uhci))
> >  		return inl(uhci->io_addr + reg);
> > -	else if (uhci_is_aspeed(uhci))
> > +#endif
> 
> Instead of making all these changes (here and in the hunks below), you
> can simply modify the definition of uhci_has_pci_registers() so that it
> always gives 0 when CONFIG_HAS_IOPORT is N.
> 
> Alan Stern

I don't think that works, for example in the hunk you quoted returning
0 from uhci_has_pci_registers() only skips over the inl() at run-time.
We're aiming to have inl() undeclared if HAS_IOPORT is unset though.
Alan Stern Dec. 31, 2021, 5:15 p.m. UTC | #3
On Fri, Dec 31, 2021 at 12:06:24PM +0100, Niklas Schnelle wrote:
> On Mon, 2021-12-27 at 15:36 -0500, Alan Stern wrote:
> > On Mon, Dec 27, 2021 at 05:43:16PM +0100, Niklas Schnelle wrote:
> > > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > > not being declared. We thus need to guard sections of code calling them
> > > as alternative access methods with CONFIG_HAS_IOPORT checks. Similarly
> > > drivers requiring these functions need to depend on HAS_IOPORT.
> > 
> > A few things in here can be improved.
> > 
> > > Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> > > Signed-off-by: Arnd Bergmann <arnd@kernel.org>
> > > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> > > ---

> > > diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
> > > index ef08d68b9714..bba320194027 100644
> > > --- a/drivers/usb/host/pci-quirks.c
> > > +++ b/drivers/usb/host/pci-quirks.c
> > > +#ifdef CONFIG_USB_PCI_AMD
> > > +#if IS_ENABLED(CONFIG_USB_UHCI_HCD) && defined(CONFIG_HAS_IOPORT)
> > 
> > In the original, the following code will be compiled even if
> > CONFIG_USB_UHCI_HCD is not enabled.  You shouldn't change that.
> 
> If this was only '#ifdef CONFIG_HAS_IOPORT' we would leave
> uhci_reset_hc() undeclared in the case where CONFIG_HAS_IOPORT is
> unset. This function however is also called from uhci-pci.c. That on
> the other hand is built only if CONFIG_USB_UHCI_HCD is set so if we
> depend on both config options we can get rid of all calls and have the
> functions undeclared.

But you changed the guard around the '#include "uhci-pci.c"' line in 
uhci-hcd.c, so uhci-pci.c won't be built if CONFIG_HAS_IOPORT is unset.  
Thus there won't be an undefined function call regardless.

You see, even if the kernel isn't configured to include a UHCI driver, 
it's still important to hand off and disable any PCI UHCI hardware when 
the system starts up.  Otherwise you can get all sorts of crazy 
interrupts and DMA from the BIOS.

> > >  /*
> > >   * Make sure the controller is completely inactive, unable to
> > >   * generate interrupts or do DMA.
> > > @@ -1273,7 +1277,8 @@ static void quirk_usb_early_handoff(struct pci_dev *pdev)
> > >  			 "Can't enable PCI device, BIOS handoff failed.\n");
> > >  		return;
> > >  	}
> > > -	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
> > > +	if (IS_ENABLED(CONFIG_USB_UHCI_HCD) &&
> > > +	    pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
> > >  		quirk_usb_handoff_uhci(pdev);
> > 
> > Same idea here.
> 
> Hmm, I'm not 100% sure if the IS_ENABLED(CONFIG_USB_UHCI_HCD) depends
> on some compiler optimizations for it to be ok that
> uhci_check_and_reset_hc() is not declared in the case where both
> CONFIG_HAS_IOPORT and CONFIG_USB_UHCI_HCD are unset. Maybe that should
> be a plain ifdef.

The reasoning should be exactly the same as in the previous case.

> > > diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
> > > index 8ae5ccd26753..8e30116b6fd2 100644
> > > --- a/drivers/usb/host/uhci-hcd.h
> > > +++ b/drivers/usb/host/uhci-hcd.h
> > > @@ -586,12 +586,14 @@ static inline int uhci_aspeed_reg(unsigned int reg)
> > >  
> > >  static inline u32 uhci_readl(const struct uhci_hcd *uhci, int reg)
> > >  {
> > > +#ifdef CONFIG_HAS_IOPORT
> > >  	if (uhci_has_pci_registers(uhci))
> > >  		return inl(uhci->io_addr + reg);
> > > -	else if (uhci_is_aspeed(uhci))
> > > +#endif
> > 
> > Instead of making all these changes (here and in the hunks below), you
> > can simply modify the definition of uhci_has_pci_registers() so that it
> > always gives 0 when CONFIG_HAS_IOPORT is N.
> > 
> > Alan Stern
> 
> I don't think that works, for example in the hunk you quoted returning
> 0 from uhci_has_pci_registers() only skips over the inl() at run-time.
> We're aiming to have inl() undeclared if HAS_IOPORT is unset though.

I see.  Do you think the following would be acceptable?  Add:

#ifdef CONFIG_HAS_IOPORT
#define UHCI_IN(x)	x
#define UHCI_OUT(x)	x
#else
#define UHCI_IN(x)	0
#define UHCI_OUT(x)
#endif

and then replace for example inl(uhci->io_addr + reg) with 
UHCI_IN(inl(uhci->io_addr + reg)).

The definition of uhci_has_pci_registers() should be updated in any 
case; there's no reason for it to do a runtime check of uhci->io_addr 
when HAS_IOPORT is disabled.

Alan Stern
Niklas Schnelle Jan. 3, 2022, 11:35 a.m. UTC | #4
On Fri, 2021-12-31 at 12:15 -0500, Alan Stern wrote:
> On Fri, Dec 31, 2021 at 12:06:24PM +0100, Niklas Schnelle wrote:
> > On Mon, 2021-12-27 at 15:36 -0500, Alan Stern wrote:
> > > On Mon, Dec 27, 2021 at 05:43:16PM +0100, Niklas Schnelle wrote:
> > > > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > > > not being declared. We thus need to guard sections of code calling them
> > > > as alternative access methods with CONFIG_HAS_IOPORT checks. Similarly
> > > > drivers requiring these functions need to depend on HAS_IOPORT.
> > > 
> > > A few things in here can be improved.
> > > 
> > > > Co-developed-by: Arnd Bergmann <arnd@kernel.org>
> > > > Signed-off-by: Arnd Bergmann <arnd@kernel.org>
> > > > Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
> > > > ---
> > > > diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
> > > > index ef08d68b9714..bba320194027 100644
> > > > --- a/drivers/usb/host/pci-quirks.c
> > > > +++ b/drivers/usb/host/pci-quirks.c
> > > > +#ifdef CONFIG_USB_PCI_AMD
> > > > +#if IS_ENABLED(CONFIG_USB_UHCI_HCD) && defined(CONFIG_HAS_IOPORT)
> > > 
> > > In the original, the following code will be compiled even if
> > > CONFIG_USB_UHCI_HCD is not enabled.  You shouldn't change that.
> > 
> > If this was only '#ifdef CONFIG_HAS_IOPORT' we would leave
> > uhci_reset_hc() undeclared in the case where CONFIG_HAS_IOPORT is
> > unset. This function however is also called from uhci-pci.c. That on
> > the other hand is built only if CONFIG_USB_UHCI_HCD is set so if we
> > depend on both config options we can get rid of all calls and have the
> > functions undeclared.
> 
> But you changed the guard around the '#include "uhci-pci.c"' line in 
> uhci-hcd.c, so uhci-pci.c won't be built if CONFIG_HAS_IOPORT is unset.  
> Thus there won't be an undefined function call regardless.

Ah thanks yes that makes sense. I seem to have gotten confused by the
uhci-hcd.c vs uhci-pci.c dependency.

> 
> You see, even if the kernel isn't configured to include a UHCI driver, 
> it's still important to hand off and disable any PCI UHCI hardware when 
> the system starts up.  Otherwise you can get all sorts of crazy 
> interrupts and DMA from the BIOS.

Thanks for the explanation, this is very helpful to understand the
context.

> 
> > > >  /*
> > > >   * Make sure the controller is completely inactive, unable to
> > > >   * generate interrupts or do DMA.
> > > > @@ -1273,7 +1277,8 @@ static void quirk_usb_early_handoff(struct pci_dev *pdev)
> > > >  			 "Can't enable PCI device, BIOS handoff failed.\n");
> > > >  		return;
> > > >  	}
> > > > -	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
> > > > +	if (IS_ENABLED(CONFIG_USB_UHCI_HCD) &&
> > > > +	    pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
> > > >  		quirk_usb_handoff_uhci(pdev);
> > > 
> > > Same idea here.
> > 
> > Hmm, I'm not 100% sure if the IS_ENABLED(CONFIG_USB_UHCI_HCD) depends
> > on some compiler optimizations for it to be ok that
> > uhci_check_and_reset_hc() is not declared in the case where both
> > CONFIG_HAS_IOPORT and CONFIG_USB_UHCI_HCD are unset. Maybe that should
> > be a plain ifdef.
> 
> The reasoning should be exactly the same as in the previous case.

Yeah with your above explanation it makes sense that we need to keep
the calls even if CONFIG_USB_UHCI_HCD is not enabled. We're also
handling the CONFIG_HAS_IOPORT=n case in quirk_usb_handoff_uhci()
anyway.

> 
> > > > diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
> > > > index 8ae5ccd26753..8e30116b6fd2 100644
> > > > --- a/drivers/usb/host/uhci-hcd.h
> > > > +++ b/drivers/usb/host/uhci-hcd.h
> > > > @@ -586,12 +586,14 @@ static inline int uhci_aspeed_reg(unsigned int reg)
> > > >  
> > > >  static inline u32 uhci_readl(const struct uhci_hcd *uhci, int reg)
> > > >  {
> > > > +#ifdef CONFIG_HAS_IOPORT
> > > >  	if (uhci_has_pci_registers(uhci))
> > > >  		return inl(uhci->io_addr + reg);
> > > > -	else if (uhci_is_aspeed(uhci))
> > > > +#endif
> > > 
> > > Instead of making all these changes (here and in the hunks below), you
> > > can simply modify the definition of uhci_has_pci_registers() so that it
> > > always gives 0 when CONFIG_HAS_IOPORT is N.
> > > 
> > > Alan Stern
> > 
> > I don't think that works, for example in the hunk you quoted returning
> > 0 from uhci_has_pci_registers() only skips over the inl() at run-time.
> > We're aiming to have inl() undeclared if HAS_IOPORT is unset though.
> 
> I see.  Do you think the following would be acceptable?  Add:
> 
> #ifdef CONFIG_HAS_IOPORT
> #define UHCI_IN(x)	x
> #define UHCI_OUT(x)	x
> #else
> #define UHCI_IN(x)	0
> #define UHCI_OUT(x)
> #endif
> 
> and then replace for example inl(uhci->io_addr + reg) with 
> UHCI_IN(inl(uhci->io_addr + reg)).

In principle that looks like a valid approach. Not sure this is better
than explicit ifdefs though. With this approach one could add
UHCI_IN()/UHCI_OUT() calls which end up as nops without realizing it as
it would disable any compile time warning for using them without
guarding against CONFIG_HAS_IOPORT being undefined.

> 
> The definition of uhci_has_pci_registers() should be updated in any 
> case; there's no reason for it to do a runtime check of uhci->io_addr 
> when HAS_IOPORT is disabled.

Agree. Interestingly same as with the "if
(IS_ENABLED(CONFIG_HAS_IOPORT))" it seems having
uhci_has_pci_registers() compile-time defined to 0 (I added a
defined(CONFIG_HAS_IOPORT) to it) makes the compiler ignore the missing
inl() decleration already. But I'm not sure if we should rely on that.
Alan Stern Jan. 3, 2022, 4:15 p.m. UTC | #5
On Mon, Jan 03, 2022 at 12:35:45PM +0100, Niklas Schnelle wrote:
> On Fri, 2021-12-31 at 12:15 -0500, Alan Stern wrote:
> > On Fri, Dec 31, 2021 at 12:06:24PM +0100, Niklas Schnelle wrote:
> > > On Mon, 2021-12-27 at 15:36 -0500, Alan Stern wrote:
> > > > On Mon, Dec 27, 2021 at 05:43:16PM +0100, Niklas Schnelle wrote:

> > > > > diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
> > > > > index 8ae5ccd26753..8e30116b6fd2 100644
> > > > > --- a/drivers/usb/host/uhci-hcd.h
> > > > > +++ b/drivers/usb/host/uhci-hcd.h
> > > > > @@ -586,12 +586,14 @@ static inline int uhci_aspeed_reg(unsigned int reg)
> > > > >  
> > > > >  static inline u32 uhci_readl(const struct uhci_hcd *uhci, int reg)
> > > > >  {
> > > > > +#ifdef CONFIG_HAS_IOPORT
> > > > >  	if (uhci_has_pci_registers(uhci))
> > > > >  		return inl(uhci->io_addr + reg);
> > > > > -	else if (uhci_is_aspeed(uhci))
> > > > > +#endif
> > > > 
> > > > Instead of making all these changes (here and in the hunks below), you
> > > > can simply modify the definition of uhci_has_pci_registers() so that it
> > > > always gives 0 when CONFIG_HAS_IOPORT is N.
> > > > 
> > > > Alan Stern
> > > 
> > > I don't think that works, for example in the hunk you quoted returning
> > > 0 from uhci_has_pci_registers() only skips over the inl() at run-time.
> > > We're aiming to have inl() undeclared if HAS_IOPORT is unset though.
> > 
> > I see.  Do you think the following would be acceptable?  Add:
> > 
> > #ifdef CONFIG_HAS_IOPORT
> > #define UHCI_IN(x)	x
> > #define UHCI_OUT(x)	x
> > #else
> > #define UHCI_IN(x)	0
> > #define UHCI_OUT(x)
> > #endif
> > 
> > and then replace for example inl(uhci->io_addr + reg) with 
> > UHCI_IN(inl(uhci->io_addr + reg)).
> 
> In principle that looks like a valid approach. Not sure this is better
> than explicit ifdefs though.

The general preference in the kernel is to avoid sprinkling #ifdef's 
throughout function definitions, and instead encapsulate their effects 
with macros or inline functions -- like this.

>  With this approach one could add
> UHCI_IN()/UHCI_OUT() calls which end up as nops without realizing it as
> it would disable any compile time warning for using them without
> guarding against CONFIG_HAS_IOPORT being undefined.

To help prevent that, we can add

#undef UHCI_IN
#undef UHCI_OUT

at the end of this section.

> > The definition of uhci_has_pci_registers() should be updated in any 
> > case; there's no reason for it to do a runtime check of uhci->io_addr 
> > when HAS_IOPORT is disabled.
> 
> Agree. Interestingly same as with the "if
> (IS_ENABLED(CONFIG_HAS_IOPORT))" it seems having
> uhci_has_pci_registers() compile-time defined to 0 (I added a
> defined(CONFIG_HAS_IOPORT) to it) makes the compiler ignore the missing
> inl() decleration already. But I'm not sure if we should rely on that.

I definitely would not rely on it.

Alan Stern
diff mbox series

Patch

diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index d630cccd2e6e..1ade46cec91a 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -212,7 +212,8 @@  int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id,
 		goto free_irq_vectors;
 	}
 
-	hcd->amd_resume_bug = (usb_hcd_amd_remote_wakeup_quirk(dev) &&
+	hcd->amd_resume_bug = (IS_ENABLED(CONFIG_USB_PCI_AMD) &&
+			usb_hcd_amd_remote_wakeup_quirk(dev) &&
 			driver->flags & (HCD_USB11 | HCD_USB3)) ? 1 : 0;
 
 	if (driver->flags & HCD_MEMORY) {
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index d1d926f8f9c2..5fb207e2d5e8 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -369,7 +369,7 @@  config USB_ISP116X_HCD
 
 config USB_ISP1362_HCD
 	tristate "ISP1362 HCD support"
-	depends on HAS_IOMEM
+	depends on HAS_IOPORT
 	depends on COMPILE_TEST # nothing uses this
 	help
 	  Supports the Philips ISP1362 chip as a host controller
@@ -605,7 +605,7 @@  endif # USB_OHCI_HCD
 
 config USB_UHCI_HCD
 	tristate "UHCI HCD (most Intel and VIA) support"
-	depends on USB_PCI || USB_UHCI_SUPPORT_NON_PCI_HC
+	depends on (USB_PCI && HAS_IOPORT) || USB_UHCI_SUPPORT_NON_PCI_HC
 	help
 	  The Universal Host Controller Interface is a standard by Intel for
 	  accessing the USB hardware in the PC (which is also called the USB
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index ef08d68b9714..bba320194027 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -60,6 +60,23 @@ 
 #define EHCI_USBLEGCTLSTS	4		/* legacy control/status */
 #define EHCI_USBLEGCTLSTS_SOOE	(1 << 13)	/* SMI on ownership change */
 
+/* ASMEDIA quirk use */
+#define ASMT_DATA_WRITE0_REG	0xF8
+#define ASMT_DATA_WRITE1_REG	0xFC
+#define ASMT_CONTROL_REG	0xE0
+#define ASMT_CONTROL_WRITE_BIT	0x02
+#define ASMT_WRITEREG_CMD	0x10423
+#define ASMT_FLOWCTL_ADDR	0xFA30
+#define ASMT_FLOWCTL_DATA	0xBA
+#define ASMT_PSEUDO_DATA	0
+
+/* Intel quirk use */
+#define USB_INTEL_XUSB2PR      0xD0
+#define USB_INTEL_USB2PRM      0xD4
+#define USB_INTEL_USB3_PSSEN   0xD8
+#define USB_INTEL_USB3PRM      0xDC
+
+#ifdef CONFIG_USB_PCI_AMD
 /* AMD quirk use */
 #define	AB_REG_BAR_LOW		0xe0
 #define	AB_REG_BAR_HIGH		0xe1
@@ -93,21 +110,6 @@ 
 #define	NB_PIF0_PWRDOWN_0	0x01100012
 #define	NB_PIF0_PWRDOWN_1	0x01100013
 
-#define USB_INTEL_XUSB2PR      0xD0
-#define USB_INTEL_USB2PRM      0xD4
-#define USB_INTEL_USB3_PSSEN   0xD8
-#define USB_INTEL_USB3PRM      0xDC
-
-/* ASMEDIA quirk use */
-#define ASMT_DATA_WRITE0_REG	0xF8
-#define ASMT_DATA_WRITE1_REG	0xFC
-#define ASMT_CONTROL_REG	0xE0
-#define ASMT_CONTROL_WRITE_BIT	0x02
-#define ASMT_WRITEREG_CMD	0x10423
-#define ASMT_FLOWCTL_ADDR	0xFA30
-#define ASMT_FLOWCTL_DATA	0xBA
-#define ASMT_PSEUDO_DATA	0
-
 /*
  * amd_chipset_gen values represent AMD different chipset generations
  */
@@ -460,50 +462,6 @@  void usb_amd_quirk_pll_disable(void)
 }
 EXPORT_SYMBOL_GPL(usb_amd_quirk_pll_disable);
 
-static int usb_asmedia_wait_write(struct pci_dev *pdev)
-{
-	unsigned long retry_count;
-	unsigned char value;
-
-	for (retry_count = 1000; retry_count > 0; --retry_count) {
-
-		pci_read_config_byte(pdev, ASMT_CONTROL_REG, &value);
-
-		if (value == 0xff) {
-			dev_err(&pdev->dev, "%s: check_ready ERROR", __func__);
-			return -EIO;
-		}
-
-		if ((value & ASMT_CONTROL_WRITE_BIT) == 0)
-			return 0;
-
-		udelay(50);
-	}
-
-	dev_warn(&pdev->dev, "%s: check_write_ready timeout", __func__);
-	return -ETIMEDOUT;
-}
-
-void usb_asmedia_modifyflowcontrol(struct pci_dev *pdev)
-{
-	if (usb_asmedia_wait_write(pdev) != 0)
-		return;
-
-	/* send command and address to device */
-	pci_write_config_dword(pdev, ASMT_DATA_WRITE0_REG, ASMT_WRITEREG_CMD);
-	pci_write_config_dword(pdev, ASMT_DATA_WRITE1_REG, ASMT_FLOWCTL_ADDR);
-	pci_write_config_byte(pdev, ASMT_CONTROL_REG, ASMT_CONTROL_WRITE_BIT);
-
-	if (usb_asmedia_wait_write(pdev) != 0)
-		return;
-
-	/* send data to device */
-	pci_write_config_dword(pdev, ASMT_DATA_WRITE0_REG, ASMT_FLOWCTL_DATA);
-	pci_write_config_dword(pdev, ASMT_DATA_WRITE1_REG, ASMT_PSEUDO_DATA);
-	pci_write_config_byte(pdev, ASMT_CONTROL_REG, ASMT_CONTROL_WRITE_BIT);
-}
-EXPORT_SYMBOL_GPL(usb_asmedia_modifyflowcontrol);
-
 void usb_amd_quirk_pll_enable(void)
 {
 	usb_amd_quirk_pll(0);
@@ -632,7 +590,52 @@  bool usb_amd_pt_check_port(struct device *device, int port)
 	return !(value & BIT(port_shift));
 }
 EXPORT_SYMBOL_GPL(usb_amd_pt_check_port);
+#endif
 
+static int usb_asmedia_wait_write(struct pci_dev *pdev)
+{
+	unsigned long retry_count;
+	unsigned char value;
+
+	for (retry_count = 1000; retry_count > 0; --retry_count) {
+		pci_read_config_byte(pdev, ASMT_CONTROL_REG, &value);
+
+		if (value == 0xff) {
+			dev_err(&pdev->dev, "%s: check_ready ERROR", __func__);
+			return -EIO;
+		}
+
+		if ((value & ASMT_CONTROL_WRITE_BIT) == 0)
+			return 0;
+
+		udelay(50);
+	}
+
+	dev_warn(&pdev->dev, "%s: check_write_ready timeout", __func__);
+	return -ETIMEDOUT;
+}
+
+void usb_asmedia_modifyflowcontrol(struct pci_dev *pdev)
+{
+	if (usb_asmedia_wait_write(pdev) != 0)
+		return;
+
+	/* send command and address to device */
+	pci_write_config_dword(pdev, ASMT_DATA_WRITE0_REG, ASMT_WRITEREG_CMD);
+	pci_write_config_dword(pdev, ASMT_DATA_WRITE1_REG, ASMT_FLOWCTL_ADDR);
+	pci_write_config_byte(pdev, ASMT_CONTROL_REG, ASMT_CONTROL_WRITE_BIT);
+
+	if (usb_asmedia_wait_write(pdev) != 0)
+		return;
+
+	/* send data to device */
+	pci_write_config_dword(pdev, ASMT_DATA_WRITE0_REG, ASMT_FLOWCTL_DATA);
+	pci_write_config_dword(pdev, ASMT_DATA_WRITE1_REG, ASMT_PSEUDO_DATA);
+	pci_write_config_byte(pdev, ASMT_CONTROL_REG, ASMT_CONTROL_WRITE_BIT);
+}
+EXPORT_SYMBOL_GPL(usb_asmedia_modifyflowcontrol);
+
+#if IS_ENABLED(CONFIG_USB_UHCI_HCD) && defined(CONFIG_HAS_IOPORT)
 /*
  * Make sure the controller is completely inactive, unable to
  * generate interrupts or do DMA.
@@ -713,6 +716,7 @@  int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base)
 	return 1;
 }
 EXPORT_SYMBOL_GPL(uhci_check_and_reset_hc);
+#endif
 
 static inline int io_type_enabled(struct pci_dev *pdev, unsigned int mask)
 {
@@ -728,7 +732,7 @@  static void quirk_usb_handoff_uhci(struct pci_dev *pdev)
 	unsigned long base = 0;
 	int i;
 
-	if (!pio_enabled(pdev))
+	if (!IS_ENABLED(CONFIG_HAS_IOPORT) || !pio_enabled(pdev))
 		return;
 
 	for (i = 0; i < PCI_STD_NUM_BARS; i++)
@@ -1273,7 +1277,8 @@  static void quirk_usb_early_handoff(struct pci_dev *pdev)
 			 "Can't enable PCI device, BIOS handoff failed.\n");
 		return;
 	}
-	if (pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
+	if (IS_ENABLED(CONFIG_USB_UHCI_HCD) &&
+	    pdev->class == PCI_CLASS_SERIAL_USB_UHCI)
 		quirk_usb_handoff_uhci(pdev);
 	else if (pdev->class == PCI_CLASS_SERIAL_USB_OHCI)
 		quirk_usb_handoff_ohci(pdev);
diff --git a/drivers/usb/host/pci-quirks.h b/drivers/usb/host/pci-quirks.h
index e729de21fad7..42eb18be37af 100644
--- a/drivers/usb/host/pci-quirks.h
+++ b/drivers/usb/host/pci-quirks.h
@@ -2,33 +2,50 @@ 
 #ifndef __LINUX_USB_PCI_QUIRKS_H
 #define __LINUX_USB_PCI_QUIRKS_H
 
-#ifdef CONFIG_USB_PCI
 void uhci_reset_hc(struct pci_dev *pdev, unsigned long base);
 int uhci_check_and_reset_hc(struct pci_dev *pdev, unsigned long base);
-int usb_hcd_amd_remote_wakeup_quirk(struct pci_dev *pdev);
+
+struct pci_dev;
+
+#ifdef CONFIG_USB_PCI_AMD
 bool usb_amd_hang_symptom_quirk(void);
 bool usb_amd_prefetch_quirk(void);
 void usb_amd_dev_put(void);
 bool usb_amd_quirk_pll_check(void);
 void usb_amd_quirk_pll_disable(void);
 void usb_amd_quirk_pll_enable(void);
-void usb_asmedia_modifyflowcontrol(struct pci_dev *pdev);
-void usb_enable_intel_xhci_ports(struct pci_dev *xhci_pdev);
-void usb_disable_xhci_ports(struct pci_dev *xhci_pdev);
 void sb800_prefetch(struct device *dev, int on);
 bool usb_amd_pt_check_port(struct device *device, int port);
 #else
-struct pci_dev;
+static inline bool usb_amd_hang_symptom_quirk(void)
+{
+	return false;
+};
+static inline bool usb_amd_prefetch_quirk(void)
+{
+	return false;
+}
+static inline bool usb_amd_quirk_pll_check(void)
+{
+	return false;
+}
 static inline void usb_amd_quirk_pll_disable(void) {}
 static inline void usb_amd_quirk_pll_enable(void) {}
-static inline void usb_asmedia_modifyflowcontrol(struct pci_dev *pdev) {}
 static inline void usb_amd_dev_put(void) {}
-static inline void usb_disable_xhci_ports(struct pci_dev *xhci_pdev) {}
 static inline void sb800_prefetch(struct device *dev, int on) {}
 static inline bool usb_amd_pt_check_port(struct device *device, int port)
 {
 	return false;
 }
+#endif /* CONFIG_USB_PCI_AMD */
+
+#ifdef CONFIG_USB_PCI
+void usb_asmedia_modifyflowcontrol(struct pci_dev *pdev);
+void usb_enable_intel_xhci_ports(struct pci_dev *xhci_pdev);
+void usb_disable_xhci_ports(struct pci_dev *xhci_pdev);
+#else
+static inline void usb_asmedia_modifyflowcontrol(struct pci_dev *pdev) {}
+static inline void usb_disable_xhci_ports(struct pci_dev *xhci_pdev) {}
 #endif  /* CONFIG_USB_PCI */
 
 #endif  /*  __LINUX_USB_PCI_QUIRKS_H  */
diff --git a/drivers/usb/host/uhci-hcd.c b/drivers/usb/host/uhci-hcd.c
index d90b869f5f40..a3b0d3d3b395 100644
--- a/drivers/usb/host/uhci-hcd.c
+++ b/drivers/usb/host/uhci-hcd.c
@@ -841,7 +841,7 @@  static int uhci_count_ports(struct usb_hcd *hcd)
 
 static const char hcd_name[] = "uhci_hcd";
 
-#ifdef CONFIG_USB_PCI
+#if defined(CONFIG_USB_PCI) && defined(CONFIG_HAS_IOPORT)
 #include "uhci-pci.c"
 #define	PCI_DRIVER		uhci_pci_driver
 #endif
diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index 8ae5ccd26753..8e30116b6fd2 100644
--- a/drivers/usb/host/uhci-hcd.h
+++ b/drivers/usb/host/uhci-hcd.h
@@ -586,12 +586,14 @@  static inline int uhci_aspeed_reg(unsigned int reg)
 
 static inline u32 uhci_readl(const struct uhci_hcd *uhci, int reg)
 {
+#ifdef CONFIG_HAS_IOPORT
 	if (uhci_has_pci_registers(uhci))
 		return inl(uhci->io_addr + reg);
-	else if (uhci_is_aspeed(uhci))
+#endif
+	if (uhci_is_aspeed(uhci))
 		return readl(uhci->regs + uhci_aspeed_reg(reg));
 #ifdef CONFIG_USB_UHCI_BIG_ENDIAN_MMIO
-	else if (uhci_big_endian_mmio(uhci))
+	if (uhci_big_endian_mmio(uhci))
 		return readl_be(uhci->regs + reg);
 #endif
 	else
@@ -600,72 +602,97 @@  static inline u32 uhci_readl(const struct uhci_hcd *uhci, int reg)
 
 static inline void uhci_writel(const struct uhci_hcd *uhci, u32 val, int reg)
 {
-	if (uhci_has_pci_registers(uhci))
+#ifdef CONFIG_HAS_IOPORT
+	if (uhci_has_pci_registers(uhci)) {
 		outl(val, uhci->io_addr + reg);
-	else if (uhci_is_aspeed(uhci))
+		return;
+	}
+#endif
+	if (uhci_is_aspeed(uhci)) {
 		writel(val, uhci->regs + uhci_aspeed_reg(reg));
+		return;
+	}
 #ifdef CONFIG_USB_UHCI_BIG_ENDIAN_MMIO
-	else if (uhci_big_endian_mmio(uhci))
+	if (uhci_big_endian_mmio(uhci)) {
 		writel_be(val, uhci->regs + reg);
+		return;
+	}
 #endif
-	else
-		writel(val, uhci->regs + reg);
+	writel(val, uhci->regs + reg);
 }
 
 static inline u16 uhci_readw(const struct uhci_hcd *uhci, int reg)
 {
+#ifdef CONFIG_HAS_IOPORT
 	if (uhci_has_pci_registers(uhci))
 		return inw(uhci->io_addr + reg);
-	else if (uhci_is_aspeed(uhci))
+#endif
+	if (uhci_is_aspeed(uhci))
 		return readl(uhci->regs + uhci_aspeed_reg(reg));
 #ifdef CONFIG_USB_UHCI_BIG_ENDIAN_MMIO
-	else if (uhci_big_endian_mmio(uhci))
+	if (uhci_big_endian_mmio(uhci))
 		return readw_be(uhci->regs + reg);
 #endif
-	else
-		return readw(uhci->regs + reg);
+	return readw(uhci->regs + reg);
 }
 
 static inline void uhci_writew(const struct uhci_hcd *uhci, u16 val, int reg)
 {
-	if (uhci_has_pci_registers(uhci))
+#ifdef CONFIG_HAS_IOPORT
+	if (uhci_has_pci_registers(uhci)) {
 		outw(val, uhci->io_addr + reg);
-	else if (uhci_is_aspeed(uhci))
+		return;
+	}
+#endif
+	if (uhci_is_aspeed(uhci)) {
 		writel(val, uhci->regs + uhci_aspeed_reg(reg));
+		return;
+	}
 #ifdef CONFIG_USB_UHCI_BIG_ENDIAN_MMIO
-	else if (uhci_big_endian_mmio(uhci))
+	if (uhci_big_endian_mmio(uhci)) {
 		writew_be(val, uhci->regs + reg);
+		return;
+	}
 #endif
-	else
-		writew(val, uhci->regs + reg);
+
+	writew(val, uhci->regs + reg);
 }
 
 static inline u8 uhci_readb(const struct uhci_hcd *uhci, int reg)
 {
+#ifdef CONFIG_HAS_IOPORT
 	if (uhci_has_pci_registers(uhci))
 		return inb(uhci->io_addr + reg);
-	else if (uhci_is_aspeed(uhci))
+#endif
+	if (uhci_is_aspeed(uhci))
 		return readl(uhci->regs + uhci_aspeed_reg(reg));
 #ifdef CONFIG_USB_UHCI_BIG_ENDIAN_MMIO
-	else if (uhci_big_endian_mmio(uhci))
+	if (uhci_big_endian_mmio(uhci))
 		return readb_be(uhci->regs + reg);
 #endif
-	else
-		return readb(uhci->regs + reg);
+
+	return readb(uhci->regs + reg);
 }
 
 static inline void uhci_writeb(const struct uhci_hcd *uhci, u8 val, int reg)
 {
-	if (uhci_has_pci_registers(uhci))
+#ifdef CONFIG_HAS_IOPORT
+	if (uhci_has_pci_registers(uhci)) {
 		outb(val, uhci->io_addr + reg);
-	else if (uhci_is_aspeed(uhci))
+		return;
+	}
+#endif
+	if (uhci_is_aspeed(uhci)) {
 		writel(val, uhci->regs + uhci_aspeed_reg(reg));
+		return;
+	}
 #ifdef CONFIG_USB_UHCI_BIG_ENDIAN_MMIO
-	else if (uhci_big_endian_mmio(uhci))
+	if (uhci_big_endian_mmio(uhci)) {
 		writeb_be(val, uhci->regs + reg);
+		return;
+	}
 #endif
-	else
-		writeb(val, uhci->regs + reg);
+	writeb(val, uhci->regs + reg);
 }
 #endif /* CONFIG_USB_UHCI_SUPPORT_NON_PCI_HC */