| Message ID | 20200219175007.13627-10-krzk@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | iomap: Constify ioreadX() iomem argument | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | Successfully applied on branch powerpc/merge (65b2623f395a4e25ab3ff4cff1c9c7623619a22d) |
| snowpatch_ozlabs/build-ppc64le | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64be | success | Build succeeded |
| snowpatch_ozlabs/build-ppc64e | success | Build succeeded |
| snowpatch_ozlabs/build-pmac32 | success | Build succeeded |
| snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 0 warnings, 5 checks, 35 lines checked |
| snowpatch_ozlabs/needsstable | success | Patch has no Fixes tags |
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,
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
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
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)
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 --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