diff mbox series

[RESEND,v2,9/9] ath5k: Constify ioreadX() iomem argument (as in generic implementation)

Message ID 20200219175007.13627-10-krzk@kernel.org
State New
Headers show
Series iomap: Constify ioreadX() iomem argument | expand

Commit Message

Krzysztof Kozlowski Feb. 19, 2020, 5:50 p.m. UTC 
The ioreadX() helpers have inconsistent interface.  On some architectures
void *__iomem address argument is a pointer to const, on some not.

Implementations of ioreadX() do not modify the memory under the address
so they can be converted to a "const" version for const-safety and
consistency among architectures.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
---
 drivers/net/wireless/ath/ath5k/ahb.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Comments

Jiri Slaby Feb. 20, 2020, 9:48 a.m. UTC | #1 
On 19. 02. 20, 18:50, Krzysztof Kozlowski wrote:
> The ioreadX() helpers have inconsistent interface.  On some architectures
> void *__iomem address argument is a pointer to const, on some not.
> 
> Implementations of ioreadX() do not modify the memory under the address
> so they can be converted to a "const" version for const-safety and
> consistency among architectures.
> 
> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> Acked-by: Kalle Valo <kvalo@codeaurora.org>
> ---
>  drivers/net/wireless/ath/ath5k/ahb.c | 10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath5k/ahb.c b/drivers/net/wireless/ath/ath5k/ahb.c
> index 2c9cec8b53d9..8bd01df369fb 100644
> --- a/drivers/net/wireless/ath/ath5k/ahb.c
> +++ b/drivers/net/wireless/ath/ath5k/ahb.c
> @@ -138,18 +138,18 @@ static int ath_ahb_probe(struct platform_device *pdev)
>  
>  	if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
>  		/* Enable WMAC AHB arbitration */
> -		reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> +		reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);

While I understand why the parameter of ioread32 should be const, I
don't see a reason for these casts on the users' side. What does it
bring except longer code to read?

thanks,
Krzysztof Kozlowski Feb. 24, 2020, 12:47 p.m. UTC | #2 
On Thu, Feb 20, 2020 at 10:48:33AM +0100, Jiri Slaby wrote:
> On 19. 02. 20, 18:50, Krzysztof Kozlowski wrote:
> > The ioreadX() helpers have inconsistent interface.  On some architectures
> > void *__iomem address argument is a pointer to const, on some not.
> > 
> > Implementations of ioreadX() do not modify the memory under the address
> > so they can be converted to a "const" version for const-safety and
> > consistency among architectures.
> > 
> > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> > Acked-by: Kalle Valo <kvalo@codeaurora.org>
> > ---
> >  drivers/net/wireless/ath/ath5k/ahb.c | 10 +++++-----
> >  1 file changed, 5 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/net/wireless/ath/ath5k/ahb.c b/drivers/net/wireless/ath/ath5k/ahb.c
> > index 2c9cec8b53d9..8bd01df369fb 100644
> > --- a/drivers/net/wireless/ath/ath5k/ahb.c
> > +++ b/drivers/net/wireless/ath/ath5k/ahb.c
> > @@ -138,18 +138,18 @@ static int ath_ahb_probe(struct platform_device *pdev)
> >  
> >  	if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
> >  		/* Enable WMAC AHB arbitration */
> > -		reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> > +		reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> 
> While I understand why the parameter of ioread32 should be const, I
> don't see a reason for these casts on the users' side. What does it
> bring except longer code to read?

Because the argument is an int:

drivers/net/wireless/ath/ath5k/ahb.c: In function ‘ath_ahb_probe’:
drivers/net/wireless/ath/ath5k/ahb.c:141:18: warning: passing argument 1 of ‘ioread32’ makes pointer from integer without a cast [-Wint-conversion]
   reg = ioread32(AR5K_AR2315_AHB_ARB_CTL);

Best regards,
Krzysztof
Geert Uytterhoeven Feb. 24, 2020, 12:54 p.m. UTC | #3 
Hi Krzysztof,

On Mon, Feb 24, 2020 at 1:47 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> On Thu, Feb 20, 2020 at 10:48:33AM +0100, Jiri Slaby wrote:
> > On 19. 02. 20, 18:50, Krzysztof Kozlowski wrote:
> > > The ioreadX() helpers have inconsistent interface.  On some architectures
> > > void *__iomem address argument is a pointer to const, on some not.
> > >
> > > Implementations of ioreadX() do not modify the memory under the address
> > > so they can be converted to a "const" version for const-safety and
> > > consistency among architectures.
> > >
> > > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> > > Acked-by: Kalle Valo <kvalo@codeaurora.org>
> > > ---
> > >  drivers/net/wireless/ath/ath5k/ahb.c | 10 +++++-----
> > >  1 file changed, 5 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/net/wireless/ath/ath5k/ahb.c b/drivers/net/wireless/ath/ath5k/ahb.c
> > > index 2c9cec8b53d9..8bd01df369fb 100644
> > > --- a/drivers/net/wireless/ath/ath5k/ahb.c
> > > +++ b/drivers/net/wireless/ath/ath5k/ahb.c
> > > @@ -138,18 +138,18 @@ static int ath_ahb_probe(struct platform_device *pdev)
> > >
> > >     if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
> > >             /* Enable WMAC AHB arbitration */
> > > -           reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> > > +           reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> >
> > While I understand why the parameter of ioread32 should be const, I
> > don't see a reason for these casts on the users' side. What does it
> > bring except longer code to read?
>
> Because the argument is an int:
>
> drivers/net/wireless/ath/ath5k/ahb.c: In function ‘ath_ahb_probe’:
> drivers/net/wireless/ath/ath5k/ahb.c:141:18: warning: passing argument 1 of ‘ioread32’ makes pointer from integer without a cast [-Wint-conversion]
>    reg = ioread32(AR5K_AR2315_AHB_ARB_CTL);

That's an argument for keeping the cast to "void __iomem *", not for
adding the "const", right?

Gr{oetje,eeting}s,

                        Geert
David Laight Feb. 24, 2020, 2 p.m. UTC | #4 
From: Geert Uytterhoeven
> Sent: 24 February 2020 12:54
> To: Krzysztof Kozlowski <krzk@kernel.org>
...
> > > > diff --git a/drivers/net/wireless/ath/ath5k/ahb.c b/drivers/net/wireless/ath/ath5k/ahb.c
> > > > index 2c9cec8b53d9..8bd01df369fb 100644
> > > > --- a/drivers/net/wireless/ath/ath5k/ahb.c
> > > > +++ b/drivers/net/wireless/ath/ath5k/ahb.c
> > > > @@ -138,18 +138,18 @@ static int ath_ahb_probe(struct platform_device *pdev)
> > > >
> > > >     if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
> > > >             /* Enable WMAC AHB arbitration */
> > > > -           reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> > > > +           reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> > >
> > > While I understand why the parameter of ioread32 should be const, I
> > > don't see a reason for these casts on the users' side. What does it
> > > bring except longer code to read?
> >
> > Because the argument is an int:
> >
> > drivers/net/wireless/ath/ath5k/ahb.c: In function ‘ath_ahb_probe’:
> > drivers/net/wireless/ath/ath5k/ahb.c:141:18: warning: passing argument 1 of ‘ioread32’ makes pointer
> from integer without a cast [-Wint-conversion]
> >    reg = ioread32(AR5K_AR2315_AHB_ARB_CTL);
> 
> That's an argument for keeping the cast to "void __iomem *", not for
> adding the "const", right?

Or more likely change the definitions to use a struct for the layout.
That also stops the constants being used in the wrong place.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
Krzysztof Kozlowski Feb. 24, 2020, 2:44 p.m. UTC | #5 
On Mon, Feb 24, 2020 at 01:54:00PM +0100, Geert Uytterhoeven wrote:
> Hi Krzysztof,
> 
> On Mon, Feb 24, 2020 at 1:47 PM Krzysztof Kozlowski <krzk@kernel.org> wrote:
> > On Thu, Feb 20, 2020 at 10:48:33AM +0100, Jiri Slaby wrote:
> > > On 19. 02. 20, 18:50, Krzysztof Kozlowski wrote:
> > > > The ioreadX() helpers have inconsistent interface.  On some architectures
> > > > void *__iomem address argument is a pointer to const, on some not.
> > > >
> > > > Implementations of ioreadX() do not modify the memory under the address
> > > > so they can be converted to a "const" version for const-safety and
> > > > consistency among architectures.
> > > >
> > > > Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
> > > > Acked-by: Kalle Valo <kvalo@codeaurora.org>
> > > > ---
> > > >  drivers/net/wireless/ath/ath5k/ahb.c | 10 +++++-----
> > > >  1 file changed, 5 insertions(+), 5 deletions(-)
> > > >
> > > > diff --git a/drivers/net/wireless/ath/ath5k/ahb.c b/drivers/net/wireless/ath/ath5k/ahb.c
> > > > index 2c9cec8b53d9..8bd01df369fb 100644
> > > > --- a/drivers/net/wireless/ath/ath5k/ahb.c
> > > > +++ b/drivers/net/wireless/ath/ath5k/ahb.c
> > > > @@ -138,18 +138,18 @@ static int ath_ahb_probe(struct platform_device *pdev)
> > > >
> > > >     if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
> > > >             /* Enable WMAC AHB arbitration */
> > > > -           reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> > > > +           reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
> > >
> > > While I understand why the parameter of ioread32 should be const, I
> > > don't see a reason for these casts on the users' side. What does it
> > > bring except longer code to read?
> >
> > Because the argument is an int:
> >
> > drivers/net/wireless/ath/ath5k/ahb.c: In function ‘ath_ahb_probe’:
> > drivers/net/wireless/ath/ath5k/ahb.c:141:18: warning: passing argument 1 of ‘ioread32’ makes pointer from integer without a cast [-Wint-conversion]
> >    reg = ioread32(AR5K_AR2315_AHB_ARB_CTL);
> 
> That's an argument for keeping the cast to "void __iomem *", not for
> adding the "const", right?

Yes, correct. Maybe I misunderstood the question... The const on the
other hand does not have to be in the cast. It is merely for making it
consistent with interface. It is not required. I also mentioned it in
the cover letter:
"PAtches 5-9 are optional cleanup, without actual impact"

Feel free to ignore this one if it is not worth the effort.

Best regards,
Krzysztof
diff mbox series

Patch

diff --git a/drivers/net/wireless/ath/ath5k/ahb.c b/drivers/net/wireless/ath/ath5k/ahb.c
index 2c9cec8b53d9..8bd01df369fb 100644
--- a/drivers/net/wireless/ath/ath5k/ahb.c
+++ b/drivers/net/wireless/ath/ath5k/ahb.c
@@ -138,18 +138,18 @@  static int ath_ahb_probe(struct platform_device *pdev)
 
 	if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
 		/* Enable WMAC AHB arbitration */
-		reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
+		reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
 		reg |= AR5K_AR2315_AHB_ARB_CTL_WLAN;
 		iowrite32(reg, (void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
 
 		/* Enable global WMAC swapping */
-		reg = ioread32((void __iomem *) AR5K_AR2315_BYTESWAP);
+		reg = ioread32((const void __iomem *) AR5K_AR2315_BYTESWAP);
 		reg |= AR5K_AR2315_BYTESWAP_WMAC;
 		iowrite32(reg, (void __iomem *) AR5K_AR2315_BYTESWAP);
 	} else {
 		/* Enable WMAC DMA access (assuming 5312 or 231x*/
 		/* TODO: check other platforms */
-		reg = ioread32((void __iomem *) AR5K_AR5312_ENABLE);
+		reg = ioread32((const void __iomem *) AR5K_AR5312_ENABLE);
 		if (to_platform_device(ah->dev)->id == 0)
 			reg |= AR5K_AR5312_ENABLE_WLAN0;
 		else
@@ -202,12 +202,12 @@  static int ath_ahb_remove(struct platform_device *pdev)
 
 	if (bcfg->devid >= AR5K_SREV_AR2315_R6) {
 		/* Disable WMAC AHB arbitration */
-		reg = ioread32((void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
+		reg = ioread32((const void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
 		reg &= ~AR5K_AR2315_AHB_ARB_CTL_WLAN;
 		iowrite32(reg, (void __iomem *) AR5K_AR2315_AHB_ARB_CTL);
 	} else {
 		/*Stop DMA access */
-		reg = ioread32((void __iomem *) AR5K_AR5312_ENABLE);
+		reg = ioread32((const void __iomem *) AR5K_AR5312_ENABLE);
 		if (to_platform_device(ah->dev)->id == 0)
 			reg &= ~AR5K_AR5312_ENABLE_WLAN0;
 		else