Nouveau - Feb 2020 - [RESEND PATCH v2 9/9] ath5k: Constify ioreadX() iomem argument (as in generic implementation)

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 at kernel.org>
Acked-by: Kalle Valo <kvalo at 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);
 		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
-- 
2.17.1

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 at kernel.org>
> > Acked-by: Kalle Valo <kvalo at 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