diff mbox series

[RFC,03/32] ACPI: Kconfig: add HAS_IOPORT dependencies

Message ID 20211227164317.4146918-4-schnelle@linux.ibm.com
State New
Headers show
Series None | expand

Commit Message

Niklas Schnelle Dec. 27, 2021, 4:42 p.m. UTC
In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
not being declared. As ACPI always uses I/O port access we depend on
HAS_IOPORT unconditionally.

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/acpi/Kconfig | 1 +
 1 file changed, 1 insertion(+)

Comments

Niklas Schnelle Dec. 27, 2021, 5:02 p.m. UTC | #1
On Mon, 2021-12-27 at 17:47 +0100, Rafael J. Wysocki wrote:
> On Mon, Dec 27, 2021 at 5:44 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > not being declared. As ACPI always uses I/O port access
> 
> The ARM64 people may not agree with this.

Maybe my wording is bad. This is my rewording of what Arnd had in his
original mail: "The ACPI subsystem needs access to I/O ports, so that
also gets a dependency."(
https://lore.kernel.org/lkml/CAK8P3a0MNbx-iuzW_-=0ab6-TTZzwV-PT_6gAC1Gp5PgYyHcrA@mail.gmail.com/
).

> 
> > we depend on HAS_IOPORT unconditionally.
> > 
> > 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/acpi/Kconfig | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> > index cdbdf68bd98f..b57f15817ede 100644
> > --- a/drivers/acpi/Kconfig
> > +++ b/drivers/acpi/Kconfig
> > @@ -9,6 +9,7 @@ config ARCH_SUPPORTS_ACPI
> >  menuconfig ACPI
> >         bool "ACPI (Advanced Configuration and Power Interface) Support"
> >         depends on ARCH_SUPPORTS_ACPI
> > +       depends on HAS_IOPORT
> >         select PNP
> >         select NLS
> >         default y if X86
> > --
> > 2.32.0
> >
Rafael J. Wysocki Dec. 27, 2021, 5:15 p.m. UTC | #2
On Mon, Dec 27, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
>
> On Mon, Dec 27, 2021 at 6:02 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> >
> > On Mon, 2021-12-27 at 17:47 +0100, Rafael J. Wysocki wrote:
> > > On Mon, Dec 27, 2021 at 5:44 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> > > > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > > > not being declared. As ACPI always uses I/O port access
> > >
> > > The ARM64 people may not agree with this.
> >
> > Maybe my wording is bad. This is my rewording of what Arnd had in his
> > original mail: "The ACPI subsystem needs access to I/O ports, so that
> > also gets a dependency."(
> > https://lore.kernel.org/lkml/CAK8P3a0MNbx-iuzW_-=0ab6-TTZzwV-PT_6gAC1Gp5PgYyHcrA@mail.gmail.com/
> > ).
>
> And my point is that on ARM64 the ACPI subsystem does not need to
> access IO ports.
>
> It may not even need to access them on x86, but that depends on the
> platform firmware in use.
>
> If arm64 is going to set HAS_IOPORT, then fine, but is it (and this
> applies to ia64 too)?
>
> > >
> > > > we depend on HAS_IOPORT unconditionally.
> > > >
> > > > 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/acpi/Kconfig | 1 +
> > > >  1 file changed, 1 insertion(+)
> > > >
> > > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> > > > index cdbdf68bd98f..b57f15817ede 100644
> > > > --- a/drivers/acpi/Kconfig
> > > > +++ b/drivers/acpi/Kconfig
> > > > @@ -9,6 +9,7 @@ config ARCH_SUPPORTS_ACPI
> > > >  menuconfig ACPI
> > > >         bool "ACPI (Advanced Configuration and Power Interface) Support"
> > > >         depends on ARCH_SUPPORTS_ACPI

Besides, I'm not sure why ARCH_SUPPORTS_ACPI cannot cover this new dependency.

> > > > +       depends on HAS_IOPORT
> > > >         select PNP
> > > >         select NLS
> > > >         default y if X86
> > > > --
> > > > 2.32.0
> > > >
> >
Niklas Schnelle Dec. 27, 2021, 5:43 p.m. UTC | #3
On Mon, 2021-12-27 at 18:15 +0100, Rafael J. Wysocki wrote:
> On Mon, Dec 27, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > On Mon, Dec 27, 2021 at 6:02 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> > > On Mon, 2021-12-27 at 17:47 +0100, Rafael J. Wysocki wrote:
> > > > On Mon, Dec 27, 2021 at 5:44 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> > > > > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > > > > not being declared. As ACPI always uses I/O port access
> > > > 
> > > > The ARM64 people may not agree with this.
> > > 
> > > Maybe my wording is bad. This is my rewording of what Arnd had in his
> > > original mail: "The ACPI subsystem needs access to I/O ports, so that
> > > also gets a dependency."(
> > > https://lore.kernel.org/lkml/CAK8P3a0MNbx-iuzW_-=0ab6-TTZzwV-PT_6gAC1Gp5PgYyHcrA@mail.gmail.com/
> > > ).
> > 
> > And my point is that on ARM64 the ACPI subsystem does not need to
> > access IO ports.
> > 
> > It may not even need to access them on x86, but that depends on the
> > platform firmware in use.

Well at least it does compile code calling outb() in
drivers/acpi/ec.c:acpi_ec_write_cmd(). Not sure if there is an
alternative path at runtime if there is then we might want to instead
use ifdefs to always use the non I/O port path if HAS_IOPORT is
undefined.

> > 
> > If arm64 is going to set HAS_IOPORT, then fine, but is it (and this
> > applies to ia64 too)?

Yes x86, arm64 and ia64 that is all arches that set ACH_SUPPORTS_ACPI
all select HAS_IOPORT too. See patch 02 or the summary in the cover
letter which notes that only s390, nds32, um, h8300, nios2, openrisc,
hexagon, csky, and xtensa do not select it.

> > 
> > > > > we depend on HAS_IOPORT unconditionally.
> > > > > 
> > > > > 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/acpi/Kconfig | 1 +
> > > > >  1 file changed, 1 insertion(+)
> > > > > 
> > > > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> > > > > index cdbdf68bd98f..b57f15817ede 100644
> > > > > --- a/drivers/acpi/Kconfig
> > > > > +++ b/drivers/acpi/Kconfig
> > > > > @@ -9,6 +9,7 @@ config ARCH_SUPPORTS_ACPI
> > > > >  menuconfig ACPI
> > > > >         bool "ACPI (Advanced Configuration and Power Interface) Support"
> > > > >         depends on ARCH_SUPPORTS_ACPI
> 
> Besides, I'm not sure why ARCH_SUPPORTS_ACPI cannot cover this new dependency.

If you prefer to have the dependency there that should work too yes.

> 
> > > > > +       depends on HAS_IOPORT
> > > > >         select PNP
> > > > >         select NLS
> > > > >         default y if X86
> > > > > --
> > > > > 2.32.0
> > > > >
Rafael J. Wysocki Dec. 28, 2021, 3:20 p.m. UTC | #4
On Mon, Dec 27, 2021 at 6:43 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote:
>
> On Mon, 2021-12-27 at 18:15 +0100, Rafael J. Wysocki wrote:
> > On Mon, Dec 27, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
> > > On Mon, Dec 27, 2021 at 6:02 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> > > > On Mon, 2021-12-27 at 17:47 +0100, Rafael J. Wysocki wrote:
> > > > > On Mon, Dec 27, 2021 at 5:44 PM Niklas Schnelle <schnelle@linux.ibm.com> wrote:
> > > > > > In a future patch HAS_IOPORT=n will result in inb()/outb() and friends
> > > > > > not being declared. As ACPI always uses I/O port access
> > > > >
> > > > > The ARM64 people may not agree with this.
> > > >
> > > > Maybe my wording is bad. This is my rewording of what Arnd had in his
> > > > original mail: "The ACPI subsystem needs access to I/O ports, so that
> > > > also gets a dependency."(
> > > > https://lore.kernel.org/lkml/CAK8P3a0MNbx-iuzW_-=0ab6-TTZzwV-PT_6gAC1Gp5PgYyHcrA@mail.gmail.com/
> > > > ).
> > >
> > > And my point is that on ARM64 the ACPI subsystem does not need to
> > > access IO ports.
> > >
> > > It may not even need to access them on x86, but that depends on the
> > > platform firmware in use.
>
> Well at least it does compile code calling outb() in
> drivers/acpi/ec.c:acpi_ec_write_cmd().

That's the EC driver which is not used on arm64 AFAICS and that driver
itself can be made depend on HAS_IOPORT.

> Not sure if there is an
> alternative path at runtime if there is then we might want to instead
> use ifdefs to always use the non I/O port path if HAS_IOPORT is
> undefined.
>
> > >
> > > If arm64 is going to set HAS_IOPORT, then fine, but is it (and this
> > > applies to ia64 too)?
>
> Yes x86, arm64 and ia64 that is all arches that set ACH_SUPPORTS_ACPI
> all select HAS_IOPORT too. See patch 02 or the summary in the cover
> letter which notes that only s390, nds32, um, h8300, nios2, openrisc,
> hexagon, csky, and xtensa do not select it.

If that is the case, there should be no need to add the extra
dependency to CONFIG_ACPI.

> > >
> > > > > > we depend on HAS_IOPORT unconditionally.
> > > > > >
> > > > > > 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/acpi/Kconfig | 1 +
> > > > > >  1 file changed, 1 insertion(+)
> > > > > >
> > > > > > diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
> > > > > > index cdbdf68bd98f..b57f15817ede 100644
> > > > > > --- a/drivers/acpi/Kconfig
> > > > > > +++ b/drivers/acpi/Kconfig
> > > > > > @@ -9,6 +9,7 @@ config ARCH_SUPPORTS_ACPI
> > > > > >  menuconfig ACPI
> > > > > >         bool "ACPI (Advanced Configuration and Power Interface) Support"
> > > > > >         depends on ARCH_SUPPORTS_ACPI
> >
> > Besides, I'm not sure why ARCH_SUPPORTS_ACPI cannot cover this new dependency.
>
> If you prefer to have the dependency there that should work too yes.

I would prefer that.

IMO, if ARCH_SUPPORTS_ACPI is set, all of the requisite dependencies
should be met.
diff mbox series

Patch

diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig
index cdbdf68bd98f..b57f15817ede 100644
--- a/drivers/acpi/Kconfig
+++ b/drivers/acpi/Kconfig
@@ -9,6 +9,7 @@  config ARCH_SUPPORTS_ACPI
 menuconfig ACPI
 	bool "ACPI (Advanced Configuration and Power Interface) Support"
 	depends on ARCH_SUPPORTS_ACPI
+	depends on HAS_IOPORT
 	select PNP
 	select NLS
 	default y if X86