| Message ID | 20220610113427.908751-2-alexandr.lobakin@intel.com |
|---|---|
| State | New |
| Headers | show |
| Series | bitops: let optimize out non-atomic bitops on compile-time constants | expand |
From: Alexander Lobakin > Sent: 10 June 2022 12:34 > > test_bit(), as any other bitmap op, takes `unsigned long *` as a > second argument (pointer to the actual bitmap), as any bitmap > itself is an array of unsigned longs. However, the ia64_get_irr() > code passes a ref to `u64` as a second argument. > This works with the ia64 bitops implementation due to that they > have `void *` as the second argument and then cast it later on. > This works with the bitmap API itself due to that `unsigned long` > has the same size on ia64 as `u64` (`unsigned long long`), but > from the compiler PoV those two are different. > Define @irr as `unsigned long` to fix that. That implies no > functional changes. Has been hidden for 16 years! Wouldn't it be better to just test the bit? As in: return irr & (1ull << bit); David > > Fixes: a58786917ce2 ("[IA64] avoid broken SAL_CACHE_FLUSH implementations") > Cc: stable@vger.kernel.org # 2.6.16+ > Reported-by: kernel test robot <lkp@intel.com> > Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com> > --- > arch/ia64/include/asm/processor.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h > index 7cbce290f4e5..757c2f6d8d4b 100644 > --- a/arch/ia64/include/asm/processor.h > +++ b/arch/ia64/include/asm/processor.h > @@ -538,7 +538,7 @@ ia64_get_irr(unsigned int vector) > { > unsigned int reg = vector / 64; > unsigned int bit = vector % 64; > - u64 irr; > + unsigned long irr; > > switch (reg) { > case 0: irr = ia64_getreg(_IA64_REG_CR_IRR0); break; > -- > 2.36.1 - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
On Fri, Jun 10, 2022 at 01:34:22PM +0200, Alexander Lobakin wrote: > test_bit(), as any other bitmap op, takes `unsigned long *` as a > second argument (pointer to the actual bitmap), as any bitmap > itself is an array of unsigned longs. However, the ia64_get_irr() > code passes a ref to `u64` as a second argument. > This works with the ia64 bitops implementation due to that they > have `void *` as the second argument and then cast it later on. > This works with the bitmap API itself due to that `unsigned long` > has the same size on ia64 as `u64` (`unsigned long long`), but > from the compiler PoV those two are different. > Define @irr as `unsigned long` to fix that. That implies no > functional changes. Has been hidden for 16 years! Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> > Fixes: a58786917ce2 ("[IA64] avoid broken SAL_CACHE_FLUSH implementations") > Cc: stable@vger.kernel.org # 2.6.16+ > Reported-by: kernel test robot <lkp@intel.com> > Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com> > --- > arch/ia64/include/asm/processor.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h > index 7cbce290f4e5..757c2f6d8d4b 100644 > --- a/arch/ia64/include/asm/processor.h > +++ b/arch/ia64/include/asm/processor.h > @@ -538,7 +538,7 @@ ia64_get_irr(unsigned int vector) > { > unsigned int reg = vector / 64; > unsigned int bit = vector % 64; > - u64 irr; > + unsigned long irr; > > switch (reg) { > case 0: irr = ia64_getreg(_IA64_REG_CR_IRR0); break; > -- > 2.36.1 >
On Fri, Jun 10, 2022 at 01:34:22PM +0200, Alexander Lobakin wrote: > test_bit(), as any other bitmap op, takes `unsigned long *` as a > second argument (pointer to the actual bitmap), as any bitmap > itself is an array of unsigned longs. However, the ia64_get_irr() > code passes a ref to `u64` as a second argument. > This works with the ia64 bitops implementation due to that they > have `void *` as the second argument and then cast it later on. > This works with the bitmap API itself due to that `unsigned long` > has the same size on ia64 as `u64` (`unsigned long long`), but > from the compiler PoV those two are different. > Define @irr as `unsigned long` to fix that. That implies no > functional changes. Has been hidden for 16 years! > > Fixes: a58786917ce2 ("[IA64] avoid broken SAL_CACHE_FLUSH implementations") > Cc: stable@vger.kernel.org # 2.6.16+ > Reported-by: kernel test robot <lkp@intel.com> > Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com> Reviewed-by: Yury Norov <yury.norov@gmail.com> > --- > arch/ia64/include/asm/processor.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h > index 7cbce290f4e5..757c2f6d8d4b 100644 > --- a/arch/ia64/include/asm/processor.h > +++ b/arch/ia64/include/asm/processor.h > @@ -538,7 +538,7 @@ ia64_get_irr(unsigned int vector) > { > unsigned int reg = vector / 64; > unsigned int bit = vector % 64; > - u64 irr; > + unsigned long irr; > > switch (reg) { > case 0: irr = ia64_getreg(_IA64_REG_CR_IRR0); break; > -- > 2.36.1
diff --git a/arch/ia64/include/asm/processor.h b/arch/ia64/include/asm/processor.h index 7cbce290f4e5..757c2f6d8d4b 100644 --- a/arch/ia64/include/asm/processor.h +++ b/arch/ia64/include/asm/processor.h @@ -538,7 +538,7 @@ ia64_get_irr(unsigned int vector) { unsigned int reg = vector / 64; unsigned int bit = vector % 64; - u64 irr; + unsigned long irr; switch (reg) { case 0: irr = ia64_getreg(_IA64_REG_CR_IRR0); break;
test_bit(), as any other bitmap op, takes `unsigned long *` as a second argument (pointer to the actual bitmap), as any bitmap itself is an array of unsigned longs. However, the ia64_get_irr() code passes a ref to `u64` as a second argument. This works with the ia64 bitops implementation due to that they have `void *` as the second argument and then cast it later on. This works with the bitmap API itself due to that `unsigned long` has the same size on ia64 as `u64` (`unsigned long long`), but from the compiler PoV those two are different. Define @irr as `unsigned long` to fix that. That implies no functional changes. Has been hidden for 16 years! Fixes: a58786917ce2 ("[IA64] avoid broken SAL_CACHE_FLUSH implementations") Cc: stable@vger.kernel.org # 2.6.16+ Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com> --- arch/ia64/include/asm/processor.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)