[PATCH 0/7] Expect immutable pointer in virt_to_phys/isa_virt_to_bus prototypes

[PATCH 0/7] Expect immutable pointer in virt_to_phys/isa_virt_to_bus prototypes

[Stanislav Kinsburskii]

This series is aimed to address compilation warnings when a constant pointer
is passed to virt_to_phys and isa_virt_to_bus functions:

  warning: passing argument 1 of ‘virt_to_phys’ discards ‘const’ qualifier from pointer target type
  warning: passing argument 1 of ‘isa_virt_to_bus’ discards ‘const’ qualifier from pointer target type

The change(s) is the same for all architectures, but it's split into a series on
per-arch basis to simplify applying and testing on the maintainers side.

The following series implements...

---

Stanislav Kinsburskii (7):
      x86: asm/io.h: Expect immutable pointer in virt_to_phys/isa_virt_to_bus prototypes
      alpha: asm/io.h: Expect immutable pointer in virt_to_phys/isa_virt_to_bus prototypes
      mips: asm/io.h: Expect immutable pointer in isa_virt_to_bus prototype
      hexagon: asm/io.h: Expect immutable pointer in virt_to_phys prototype
      ia64: asm/io.h: Expect immutable pointer in virt_to_phys prototype
      powerpc: asm/io.h: Expect immutable pointer in virt_to_phys prototype
      asm-generic/io.h: Expect immutable pointer in virt_to_phys


 arch/alpha/include/asm/io.h   |    6 +++---
 arch/hexagon/include/asm/io.h |    2 +-
 arch/ia64/include/asm/io.h    |    2 +-
 arch/mips/include/asm/io.h    |    2 +-
 arch/powerpc/include/asm/io.h |    2 +-
 arch/x86/include/asm/io.h     |    4 ++--
 include/asm-generic/io.h      |    2 +-
 7 files changed, 10 insertions(+), 10 deletions(-)

[PATCH 6/7] powerpc: asm/io.h: Expect immutable pointer in virt_to_phys prototype

[Stanislav Kinsburskii]

From: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>

These helper function - virt_to_phys - doesn't need the address pointer to
be mutable.

In the same time expecting it to be mutable leads to the following build
warning for constant pointers:

  warning: passing argument 1 of ‘virt_to_phys’ discards ‘const’ qualifier from pointer target type

Signed-off-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
CC: Michael Ellerman <mpe@ellerman.id.au>
CC: Nicholas Piggin <npiggin@gmail.com>
CC: Christophe Leroy <christophe.leroy@csgroup.eu>
CC: Geert Uytterhoeven <geert@linux-m68k.org>
CC: Bjorn Helgaas <bhelgaas@google.com>
CC: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: linuxppc-dev@lists.ozlabs.org
CC: linux-kernel@vger.kernel.org
---
 arch/powerpc/include/asm/io.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index f1e657c9bbe8..c287eeb9536f 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -959,7 +959,7 @@ extern void __iomem *__ioremap_caller(phys_addr_t, unsigned long size,
  *	almost all conceivable cases a device driver should not be using
  *	this function
  */
-static inline unsigned long virt_to_phys(volatile void * address)
+static inline unsigned long virt_to_phys(const volatile void * address)
 {
 	WARN_ON(IS_ENABLED(CONFIG_DEBUG_VIRTUAL) && !virt_addr_valid(address));
 

Re: [PATCH 0/7] Expect immutable pointer in virt_to_phys/isa_virt_to_bus prototypes

[Arnd Bergmann]

On Sat, Apr 15, 2023, at 12:17, Stanislav Kinsburskii wrote:
> This series is aimed to address compilation warnings when a constant pointer
> is passed to virt_to_phys and isa_virt_to_bus functions:
>
>   warning: passing argument 1 of ‘virt_to_phys’ discards ‘const’ 
> qualifier from pointer target type
>   warning: passing argument 1 of ‘isa_virt_to_bus’ discards ‘const’ 
> qualifier from pointer target type
>
> The change(s) is the same for all architectures, but it's split into a series on
> per-arch basis to simplify applying and testing on the maintainers side.
>

Looks all good to me. If everyone is happy with it, I'll queue it up
after in the asm-generic tree for 6.5, once rc1 is out.

 Arnd

Re: [PATCH 0/7] Expect immutable pointer in virt_to_phys/isa_virt_to_bus prototypes

[Linus Walleij]

On Thu, Apr 27, 2023 at 7:41 PM Stanislav Kinsburskii
<skinsburskii@linux.microsoft.com> wrote:

> This series is aimed to address compilation warnings when a constant pointer
> is passed to virt_to_phys and isa_virt_to_bus functions:
>
>   warning: passing argument 1 of ‘virt_to_phys’ discards ‘const’ qualifier from pointer target type
>   warning: passing argument 1 of ‘isa_virt_to_bus’ discards ‘const’ qualifier from pointer target type
>
> The change(s) is the same for all architectures, but it's split into a series on
> per-arch basis to simplify applying and testing on the maintainers side.
>
> The following series implements...

This is nice.
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

I am working with an adjacent task, which is to make virt_to_pfn() and
pfn_to_virt() into static inlines. I might need to rebase my work on top
of this but it should be doable, I am currently stressing the buildbots
with this with the idea to propose it to Arnd once v6.4-rc1 is out:
https://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-integrator.git/log/?h=b4/virt-to-pfn-v6-4-rc1

Yours,
Linus Walleij

Re: [PATCH 0/7] Expect immutable pointer in virt_to_phys/isa_virt_to_bus prototypes

[Stanislav Kinsburskii]

On Fri, Apr 28, 2023 at 08:40:51AM +0100, Arnd Bergmann wrote:
> On Sat, Apr 15, 2023, at 12:17, Stanislav Kinsburskii wrote:
> > This series is aimed to address compilation warnings when a constant pointer
> > is passed to virt_to_phys and isa_virt_to_bus functions:
> >
> >   warning: passing argument 1 of ‘virt_to_phys’ discards ‘const’ 
> > qualifier from pointer target type
> >   warning: passing argument 1 of ‘isa_virt_to_bus’ discards ‘const’ 
> > qualifier from pointer target type
> >
> > The change(s) is the same for all architectures, but it's split into a series on
> > per-arch basis to simplify applying and testing on the maintainers side.
> >
> 
> Looks all good to me. If everyone is happy with it, I'll queue it up
> after in the asm-generic tree for 6.5, once rc1 is out.
> 

Hello Arnd,
Is the plan to merge this series into 6.5 still on?

Stanislav

>  Arnd

Re: [PATCH 0/7] Expect immutable pointer in virt_to_phys/isa_virt_to_bus prototypes

[Michael Ellerman]

On Sat, 15 Apr 2023 04:17:19 -0700, Stanislav Kinsburskii wrote:
> This series is aimed to address compilation warnings when a constant pointer
> is passed to virt_to_phys and isa_virt_to_bus functions:
> 
>   warning: passing argument 1 of ‘virt_to_phys’ discards ‘const’ qualifier from pointer target type
>   warning: passing argument 1 of ‘isa_virt_to_bus’ discards ‘const’ qualifier from pointer target type
> 
> The change(s) is the same for all architectures, but it's split into a series on
> per-arch basis to simplify applying and testing on the maintainers side.
> 
> [...]

Patch 6 applied to powerpc/next.

[6/7] powerpc: asm/io.h: Expect immutable pointer in virt_to_phys prototype
      https://git.kernel.org/powerpc/c/b28d1ccf921a4333be14017d82066386d419e638

cheers