[1/3] powerpc/io: Add __raw_writeq_be() __raw_rm_writeq_be()

Message ID 20180514125033.12000-1-mpe@ellerman.id.au
State Accepted
Commit 8056fe28d04607106e7d418bd9ee2e63562def50
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  • [1/3] powerpc/io: Add __raw_writeq_be() __raw_rm_writeq_be()
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Commit Message

Michael Ellerman May 14, 2018, 12:50 p.m.
Add byte-swapping versions of __raw_writeq() and __raw_rm_writeq().

This allows us to avoid sparse warnings caused by passing __be64 to
__raw_writeq(), which takes unsigned long:

  arch/powerpc/platforms/powernv/pci-ioda.c:1981:38:
  warning: incorrect type in argument 1 (different base types)
      expected unsigned long [unsigned] v
      got restricted __be64 [usertype] <noident>

It's also generally preferable to use a byte-swapping accessor rather
than doing it by hand in the code, which is more bug prone.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 arch/powerpc/include/asm/io.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

Comments

Samuel Mendoza-Jonas May 18, 2018, 6:39 a.m. | #1
On Mon, 2018-05-14 at 22:50 +1000, Michael Ellerman wrote:
> Add byte-swapping versions of __raw_writeq() and __raw_rm_writeq().
> 
> This allows us to avoid sparse warnings caused by passing __be64 to
> __raw_writeq(), which takes unsigned long:
> 
>   arch/powerpc/platforms/powernv/pci-ioda.c:1981:38:
>   warning: incorrect type in argument 1 (different base types)
>       expected unsigned long [unsigned] v
>       got restricted __be64 [usertype] <noident>
> 
> It's also generally preferable to use a byte-swapping accessor rather
> than doing it by hand in the code, which is more bug prone.
> 
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

For this and the following patches:

Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>

> ---
>  arch/powerpc/include/asm/io.h | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
> index af074923d598..e0331e754568 100644
> --- a/arch/powerpc/include/asm/io.h
> +++ b/arch/powerpc/include/asm/io.h
> @@ -367,6 +367,11 @@ static inline void __raw_writeq(unsigned long v, volatile void __iomem *addr)
>  	*(volatile unsigned long __force *)PCI_FIX_ADDR(addr) = v;
>  }
>  
> +static inline void __raw_writeq_be(unsigned long v, volatile void __iomem *addr)
> +{
> +	__raw_writeq((__force unsigned long)cpu_to_be64(v), addr);
> +}
> +
>  /*
>   * Real mode versions of the above. Those instructions are only supposed
>   * to be used in hypervisor real mode as per the architecture spec.
> @@ -395,6 +400,11 @@ static inline void __raw_rm_writeq(u64 val, volatile void __iomem *paddr)
>  		: : "r" (val), "r" (paddr) : "memory");
>  }
>  
> +static inline void __raw_rm_writeq_be(u64 val, volatile void __iomem *paddr)
> +{
> +	__raw_rm_writeq((__force u64)cpu_to_be64(val), paddr);
> +}
> +
>  static inline u8 __raw_rm_readb(volatile void __iomem *paddr)
>  {
>  	u8 ret;
Michael Ellerman May 18, 2018, noon | #2
Samuel Mendoza-Jonas <sam@mendozajonas.com> writes:

> On Mon, 2018-05-14 at 22:50 +1000, Michael Ellerman wrote:
>> Add byte-swapping versions of __raw_writeq() and __raw_rm_writeq().
>> 
>> This allows us to avoid sparse warnings caused by passing __be64 to
>> __raw_writeq(), which takes unsigned long:
>> 
>>   arch/powerpc/platforms/powernv/pci-ioda.c:1981:38:
>>   warning: incorrect type in argument 1 (different base types)
>>       expected unsigned long [unsigned] v
>>       got restricted __be64 [usertype] <noident>
>> 
>> It's also generally preferable to use a byte-swapping accessor rather
>> than doing it by hand in the code, which is more bug prone.
>> 
>> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
>
> For this and the following patches:
>
> Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>

Thanks.

cheers
Michael Ellerman May 21, 2018, 10:01 a.m. | #3
On Mon, 2018-05-14 at 12:50:31 UTC, Michael Ellerman wrote:
> Add byte-swapping versions of __raw_writeq() and __raw_rm_writeq().
> 
> This allows us to avoid sparse warnings caused by passing __be64 to
> __raw_writeq(), which takes unsigned long:
> 
>   arch/powerpc/platforms/powernv/pci-ioda.c:1981:38:
>   warning: incorrect type in argument 1 (different base types)
>       expected unsigned long [unsigned] v
>       got restricted __be64 [usertype] <noident>
> 
> It's also generally preferable to use a byte-swapping accessor rather
> than doing it by hand in the code, which is more bug prone.
> 
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>

Series applied to powerpc next.

https://git.kernel.org/powerpc/c/8056fe28d04607106e7d418bd9ee2e

cheers

Patch

diff --git a/arch/powerpc/include/asm/io.h b/arch/powerpc/include/asm/io.h
index af074923d598..e0331e754568 100644
--- a/arch/powerpc/include/asm/io.h
+++ b/arch/powerpc/include/asm/io.h
@@ -367,6 +367,11 @@  static inline void __raw_writeq(unsigned long v, volatile void __iomem *addr)
 	*(volatile unsigned long __force *)PCI_FIX_ADDR(addr) = v;
 }
 
+static inline void __raw_writeq_be(unsigned long v, volatile void __iomem *addr)
+{
+	__raw_writeq((__force unsigned long)cpu_to_be64(v), addr);
+}
+
 /*
  * Real mode versions of the above. Those instructions are only supposed
  * to be used in hypervisor real mode as per the architecture spec.
@@ -395,6 +400,11 @@  static inline void __raw_rm_writeq(u64 val, volatile void __iomem *paddr)
 		: : "r" (val), "r" (paddr) : "memory");
 }
 
+static inline void __raw_rm_writeq_be(u64 val, volatile void __iomem *paddr)
+{
+	__raw_rm_writeq((__force u64)cpu_to_be64(val), paddr);
+}
+
 static inline u8 __raw_rm_readb(volatile void __iomem *paddr)
 {
 	u8 ret;