diff mbox series

[5/6] sparc32: Do not select GENERIC_ISA_DMA

Message ID 20240223-sam-fix-sparc32-all-builds-v1-5-5c60fd5c9250@ravnborg.org
State New
Headers show
Series sparc32: build fixes for all{yes,mod}config builds | expand

Commit Message

Sam Ravnborg via B4 Relay Feb. 23, 2024, 7:36 p.m. UTC 
From: Sam Ravnborg <sam@ravnborg.org>

sparc32 do not support generic isa dma, so do not select the symbol.
Without this fix, the following patch would break the build with a
missing prototype.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Maciej W. Rozycki <macro@orcam.me.uk>
Fixes: 66bcd06099bb ("parport_pc: Also enable driver for PCI systems")
---
 arch/sparc/Kconfig | 4 ----
 1 file changed, 4 deletions(-)

Comments

Randy Dunlap Feb. 24, 2024, 12:32 a.m. UTC | #1 
On 2/23/24 11:36, Sam Ravnborg via B4 Relay wrote:
> From: Sam Ravnborg <sam@ravnborg.org>
> 
> sparc32 do not support generic isa dma, so do not select the symbol.
> Without this fix, the following patch would break the build with a
> missing prototype.
> 
> Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
> Cc: Andreas Larsson <andreas@gaisler.com>
> Cc: "David S. Miller" <davem@davemloft.net>
> Cc: Randy Dunlap <rdunlap@infradead.org>
> Cc: Maciej W. Rozycki <macro@orcam.me.uk>
> Fixes: 66bcd06099bb ("parport_pc: Also enable driver for PCI systems")

Acked-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested

> ---
>  arch/sparc/Kconfig | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
> index 734f23daecca..d08a5662ea60 100644
> --- a/arch/sparc/Kconfig
> +++ b/arch/sparc/Kconfig
> @@ -138,10 +138,6 @@ config HIGHMEM
>  	default y if SPARC32
>  	select KMAP_LOCAL
>  
> -config GENERIC_ISA_DMA
> -	bool
> -	default y if SPARC32
> -
>  config PGTABLE_LEVELS
>  	default 4 if 64BIT
>  	default 3
>
Maciej W. Rozycki Feb. 24, 2024, 2:55 a.m. UTC | #2 
On Fri, 23 Feb 2024, Sam Ravnborg via B4 Relay wrote:

> sparc32 do not support generic isa dma, so do not select the symbol.
> Without this fix, the following patch would break the build with a
> missing prototype.

 Not according to my observations, kernel/dma.c is always built for 
GENERIC_ISA_DMA configurations, so:

kernel/dma.c:70:5: error: no previous prototype for 'request_dma' [-Werror=missing-prototypes]
   70 | int request_dma(unsigned int dmanr, const char * device_id)
      |     ^~~~~~~~~~~
kernel/dma.c:88:6: error: no previous prototype for 'free_dma' [-Werror=missing-prototypes]
   88 | void free_dma(unsigned int dmanr)
      |      ^~~~~~~~

are issued regardless (and FAOD with PARPORT_PC unset).

 I can't speak for SPARC support for ISA DMA, but it seems to me like the 
second sentence would best be removed, as would the Fixes: tag (in favour 
to:

Fixes: 0fcb70851fbf ("Makefile.extrawarn: turn on missing-prototypes globally")

I presume), and possibly the messages quoted above included instead.

  Maciej
Maciej W. Rozycki Feb. 24, 2024, 5:29 a.m. UTC | #3 
On Sat, 24 Feb 2024, Maciej W. Rozycki wrote:

> > sparc32 do not support generic isa dma, so do not select the symbol.
> > Without this fix, the following patch would break the build with a
> > missing prototype.
> 
>  Not according to my observations, kernel/dma.c is always built for 
> GENERIC_ISA_DMA configurations, so:
> 
> kernel/dma.c:70:5: error: no previous prototype for 'request_dma' [-Werror=missing-prototypes]
>    70 | int request_dma(unsigned int dmanr, const char * device_id)
>       |     ^~~~~~~~~~~
> kernel/dma.c:88:6: error: no previous prototype for 'free_dma' [-Werror=missing-prototypes]
>    88 | void free_dma(unsigned int dmanr)
>       |      ^~~~~~~~
> 
> are issued regardless (and FAOD with PARPORT_PC unset).
> 
>  I can't speak for SPARC support for ISA DMA, but it seems to me like the 
> second sentence would best be removed, as would the Fixes: tag (in favour 
> to:
> 
> Fixes: 0fcb70851fbf ("Makefile.extrawarn: turn on missing-prototypes globally")
> 
> I presume), and possibly the messages quoted above included instead.

 Actually I think ZONE_DMA should go too (it's linked to GENERIC_ISA_DMA, 
isn't it? -- cf. commit 5ac6da669e24 ("[PATCH] Set CONFIG_ZONE_DMA for 
arches with GENERIC_ISA_DMA")), and the whole thing use:

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")

The GENERIC_ISA_DMA option itself was added to arch/sparc/config.in with 
2.5.31 as:

define_bool CONFIG_GENERIC_ISA_DMA y

despite of:

define_bool CONFIG_ISA n

for a reason not clear to me (BLK_DEV_FD? -- but on SPARC that uses some 
hacks to work in the absence of ISA DMA anyway).

 Am I missing anything here?

  Maciej
Sam Ravnborg Feb. 24, 2024, 7:59 a.m. UTC | #4 
Hi Marciej,

On Sat, Feb 24, 2024 at 05:29:43AM +0000, Maciej W. Rozycki wrote:
> On Sat, 24 Feb 2024, Maciej W. Rozycki wrote:
> 
> > > sparc32 do not support generic isa dma, so do not select the symbol.
> > > Without this fix, the following patch would break the build with a
> > > missing prototype.
> > 
> >  Not according to my observations, kernel/dma.c is always built for 
> > GENERIC_ISA_DMA configurations, so:
> > 
> > kernel/dma.c:70:5: error: no previous prototype for 'request_dma' [-Werror=missing-prototypes]
> >    70 | int request_dma(unsigned int dmanr, const char * device_id)
> >       |     ^~~~~~~~~~~
> > kernel/dma.c:88:6: error: no previous prototype for 'free_dma' [-Werror=missing-prototypes]
> >    88 | void free_dma(unsigned int dmanr)
> >       |      ^~~~~~~~
> > 
> > are issued regardless (and FAOD with PARPORT_PC unset).
> > 
> >  I can't speak for SPARC support for ISA DMA, but it seems to me like the 
> > second sentence would best be removed, as would the Fixes: tag (in favour 
> > to:
> > 
> > Fixes: 0fcb70851fbf ("Makefile.extrawarn: turn on missing-prototypes globally")
> > 
> > I presume), and possibly the messages quoted above included instead.

Thanks, I will update in v2.

> 
>  Actually I think ZONE_DMA should go too (it's linked to GENERIC_ISA_DMA, 
> isn't it? -- cf. commit 5ac6da669e24 ("[PATCH] Set CONFIG_ZONE_DMA for 
> arches with GENERIC_ISA_DMA")), and the whole thing use:
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> 
> The GENERIC_ISA_DMA option itself was added to arch/sparc/config.in with 
> 2.5.31 as:
> 
> define_bool CONFIG_GENERIC_ISA_DMA y
> 
> despite of:
> 
> define_bool CONFIG_ISA n
> 
> for a reason not clear to me (BLK_DEV_FD? -- but on SPARC that uses some 
> hacks to work in the absence of ISA DMA anyway).
> 
>  Am I missing anything here?
Nice find - the code below conforms you are right:

	max_zone_pfn[ZONE_DMA] = max_low_pfn;
	max_zone_pfn[ZONE_NORMAL] = max_low_pfn;

As they are set to the same value there is no smaller ZONE_DMA area.
I will add an extra patch for this in v2.

	Sam
Arnd Bergmann Feb. 24, 2024, 11:24 a.m. UTC | #5 
On Sat, Feb 24, 2024, at 06:29, Maciej W. Rozycki wrote:
> On Sat, 24 Feb 2024, Maciej W. Rozycki wrote:
>
> The GENERIC_ISA_DMA option itself was added to arch/sparc/config.in with 
> 2.5.31 as:
>
> define_bool CONFIG_GENERIC_ISA_DMA y
>
> despite of:
>
> define_bool CONFIG_ISA n

I think I've seen any combination of CONFIG_ISA (the 62/98 pin slots), CONFIG_GENERIC_ISA_DMA (the request_dma() interface) and
CONFIG_ISA_DMA_API (the set_dma_addr()/enable_dma() type interface),
but I agree that sparc should have none of the three as both
floppy and parport use some other interface.

> for a reason not clear to me (BLK_DEV_FD? -- but on SPARC that uses some 
> hacks to work in the absence of ISA DMA anyway).
>
>  Am I missing anything here?

I think it was part of the ISA DMA lookalike that got removed
in 334ae614772b ("sparc: Kill SBUS DVMA layer.") and should
have been changed back then.

     Arnd
Sam Ravnborg Feb. 24, 2024, 5:14 p.m. UTC | #6 
Hi Arnd,

On Sat, Feb 24, 2024 at 12:24:01PM +0100, Arnd Bergmann wrote:
> On Sat, Feb 24, 2024, at 06:29, Maciej W. Rozycki wrote:
> > On Sat, 24 Feb 2024, Maciej W. Rozycki wrote:
> >
> > The GENERIC_ISA_DMA option itself was added to arch/sparc/config.in with 
> > 2.5.31 as:
> >
> > define_bool CONFIG_GENERIC_ISA_DMA y
> >
> > despite of:
> >
> > define_bool CONFIG_ISA n
> 
> I think I've seen any combination of CONFIG_ISA (the 62/98 pin slots), CONFIG_GENERIC_ISA_DMA (the request_dma() interface) and
> CONFIG_ISA_DMA_API (the set_dma_addr()/enable_dma() type interface),
> but I agree that sparc should have none of the three as both
> floppy and parport use some other interface.
> 
> > for a reason not clear to me (BLK_DEV_FD? -- but on SPARC that uses some 
> > hacks to work in the absence of ISA DMA anyway).
> >
> >  Am I missing anything here?
> 
> I think it was part of the ISA DMA lookalike that got removed
> in 334ae614772b ("sparc: Kill SBUS DVMA layer.") and should
> have been changed back then.

Hmm, that may well be the case.

I checked and sparc32 do not set any ISA symbols anymore
so we should be OK now.

I decided to just drop the Fixes: tag to not confuse anyone.

	Sam
diff mbox series

Patch

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 734f23daecca..d08a5662ea60 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -138,10 +138,6 @@  config HIGHMEM
 	default y if SPARC32
 	select KMAP_LOCAL
 
-config GENERIC_ISA_DMA
-	bool
-	default y if SPARC32
-
 config PGTABLE_LEVELS
 	default 4 if 64BIT
 	default 3