| Message ID | 1410185480-5153-1-git-send-email-rric@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Robert, On 08/09/14 15:11, Robert Richter wrote: > From: Robert Richter <rrichter@cavium.com> > > Fixing 32 bit compatibility by using ULL for u64 constants. > > Signed-off-by: Robert Richter <rrichter@cavium.com> > --- > drivers/irqchip/irq-gic-v3.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c > index 57eaa5a0b1e3..9e13c87c7dfe 100644 > --- a/drivers/irqchip/irq-gic-v3.c > +++ b/drivers/irqchip/irq-gic-v3.c > @@ -441,7 +441,7 @@ static u16 gic_compute_target_list(int *base_cpu, const struct cpumask *mask, > > mpidr = cpu_logical_map(cpu); > > - if (cluster_id != (mpidr & ~0xffUL)) { > + if (cluster_id != (mpidr & ~0xffULL)) { > cpu--; > goto out; > } > @@ -479,7 +479,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > smp_wmb(); > > for_each_cpu_mask(cpu, *mask) { > - u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; > + u64 cluster_id = cpu_logical_map(cpu) & ~0xffULL; > u16 tlist; > > tlist = gic_compute_target_list(&cpu, mask, cluster_id); > Yeah, and there are many more. I'm currently sitting on a rather long queue of GICv3-related 32bit patches. I'll try to get that posted shortly. Thanks, M.
Hello Robert, On Mon, Sep 08, 2014 at 04:11:19PM +0200, Robert Richter wrote: > From: Robert Richter <rrichter@cavium.com> > > Fixing 32 bit compatibility by using ULL for u64 constants. > > Signed-off-by: Robert Richter <rrichter@cavium.com> > --- > drivers/irqchip/irq-gic-v3.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c > index 57eaa5a0b1e3..9e13c87c7dfe 100644 > --- a/drivers/irqchip/irq-gic-v3.c > +++ b/drivers/irqchip/irq-gic-v3.c > @@ -441,7 +441,7 @@ static u16 gic_compute_target_list(int *base_cpu, const struct cpumask *mask, > > mpidr = cpu_logical_map(cpu); > > - if (cluster_id != (mpidr & ~0xffUL)) { > + if (cluster_id != (mpidr & ~0xffULL)) { > cpu--; > goto out; > } > @@ -479,7 +479,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > smp_wmb(); > > for_each_cpu_mask(cpu, *mask) { > - u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; > + u64 cluster_id = cpu_logical_map(cpu) & ~0xffULL; This doesn't change anything, does it? I wonder if it would be cleaner to use (u64)0xff here. Or still better put the determination of the current cluster id(?) into a static inline function? Further, apart from arm and arm64 all other arch defining cpu_logical_map (m32r, mips, mn10300, parisc, sh, sparc, um, xtensa) return an int. (Three of them return just the cpu parameter which at least for irq-gic-v3 is an int, too.) Best regards Uwe
On 09.09.14 10:00:42, Uwe Kleine-König wrote: > On Mon, Sep 08, 2014 at 04:11:19PM +0200, Robert Richter wrote: > > @@ -479,7 +479,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > > smp_wmb(); > > > > for_each_cpu_mask(cpu, *mask) { > > - u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; > > + u64 cluster_id = cpu_logical_map(cpu) & ~0xffULL; > This doesn't change anything, does it? It does, not in 64 bit but in 32 bit there unsigned long is 32 bit. So, bit masks are broken if you compile a 32 bit kernel. > I wonder if it would be cleaner to use (u64)0xff here. No, that's ULL for. This is commonly used in x86 too. -Robert
On Tue, Sep 09, 2014 at 11:12:01AM +0200, Robert Richter wrote: > On 09.09.14 10:00:42, Uwe Kleine-König wrote: > > On Mon, Sep 08, 2014 at 04:11:19PM +0200, Robert Richter wrote: > > > > @@ -479,7 +479,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > > > smp_wmb(); > > > > > > for_each_cpu_mask(cpu, *mask) { > > > - u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; > > > + u64 cluster_id = cpu_logical_map(cpu) & ~0xffULL; > > This doesn't change anything, does it? > > It does, not in 64 bit but in 32 bit there unsigned long is 32 > bit. So, bit masks are broken if you compile a 32 bit kernel. Can you make an example where the result actually changes? > > I wonder if it would be cleaner to use (u64)0xff here. > > No, that's ULL for. This is commonly used in x86 too. I don't care much here, but I'd say ULL is to force an unsigned long long. If you want to make it obvious that you want a 64bit value, a cast to u64 makes this more clear. Best regards Uwe
On 09.09.14 11:19:12, Uwe Kleine-König wrote: > On Tue, Sep 09, 2014 at 11:12:01AM +0200, Robert Richter wrote: > > On 09.09.14 10:00:42, Uwe Kleine-König wrote: > > > On Mon, Sep 08, 2014 at 04:11:19PM +0200, Robert Richter wrote: > > > > > > @@ -479,7 +479,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > > > > smp_wmb(); > > > > > > > > for_each_cpu_mask(cpu, *mask) { > > > > - u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; > > > > + u64 cluster_id = cpu_logical_map(cpu) & ~0xffULL; > > > This doesn't change anything, does it? > > > > It does, not in 64 bit but in 32 bit there unsigned long is 32 > > bit. So, bit masks are broken if you compile a 32 bit kernel. > Can you make an example where the result actually changes? Upper 32 bits will be cleared above. > > > I wonder if it would be cleaner to use (u64)0xff here. > > > > No, that's ULL for. This is commonly used in x86 too. > I don't care much here, but I'd say ULL is to force an unsigned long > long. If you want to make it obvious that you want a 64bit value, a cast > to u64 makes this more clear. ULL is no cast at all. -Robert
On Tue, Sep 09, 2014 at 11:26:53AM +0200, Robert Richter wrote: > On 09.09.14 11:19:12, Uwe Kleine-König wrote: > > On Tue, Sep 09, 2014 at 11:12:01AM +0200, Robert Richter wrote: > > > On 09.09.14 10:00:42, Uwe Kleine-König wrote: > > > > On Mon, Sep 08, 2014 at 04:11:19PM +0200, Robert Richter wrote: > > > > > > > > @@ -479,7 +479,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > > > > > smp_wmb(); > > > > > > > > > > for_each_cpu_mask(cpu, *mask) { > > > > > - u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; > > > > > + u64 cluster_id = cpu_logical_map(cpu) & ~0xffULL; > > > > This doesn't change anything, does it? > > > > > > It does, not in 64 bit but in 32 bit there unsigned long is 32 > > > bit. So, bit masks are broken if you compile a 32 bit kernel. > > Can you make an example where the result actually changes? > > Upper 32 bits will be cleared above. ah, I missed the ~ while thinking about the difference. > > > > I wonder if it would be cleaner to use (u64)0xff here. > > > > > > No, that's ULL for. This is commonly used in x86 too. > > I don't care much here, but I'd say ULL is to force an unsigned long > > long. If you want to make it obvious that you want a 64bit value, a cast > > to u64 makes this more clear. > > ULL is no cast at all. That's irrelevant here if it's a cast or not. It makes the constant be an unsigned long long one. If you want an unsigned long long value, use ULL (or a cast to unsigned long long if the value permits), if you want an u64 use a cast to u64. Probably it doesn't make sense to continue to argue here. The type of cpu_logical_map(cpu) varies per architecture but is always <= 64 bits wide and IIRC unsigned long long is guaranteed to be >= 64 bits wide so everything is fine with your patch today. Best regards Uwe
On Mon, Sep 08, 2014 at 03:24:12PM +0100, Marc Zyngier wrote: > Hi Robert, > > On 08/09/14 15:11, Robert Richter wrote: > > From: Robert Richter <rrichter@cavium.com> > > > > Fixing 32 bit compatibility by using ULL for u64 constants. > > > > Signed-off-by: Robert Richter <rrichter@cavium.com> > > --- > > drivers/irqchip/irq-gic-v3.c | 4 ++-- > > 1 file changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c > > index 57eaa5a0b1e3..9e13c87c7dfe 100644 > > --- a/drivers/irqchip/irq-gic-v3.c > > +++ b/drivers/irqchip/irq-gic-v3.c > > @@ -441,7 +441,7 @@ static u16 gic_compute_target_list(int *base_cpu, const struct cpumask *mask, > > > > mpidr = cpu_logical_map(cpu); > > > > - if (cluster_id != (mpidr & ~0xffUL)) { > > + if (cluster_id != (mpidr & ~0xffULL)) { > > cpu--; > > goto out; > > } > > @@ -479,7 +479,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > > smp_wmb(); > > > > for_each_cpu_mask(cpu, *mask) { > > - u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; > > + u64 cluster_id = cpu_logical_map(cpu) & ~0xffULL; > > u16 tlist; > > > > tlist = gic_compute_target_list(&cpu, mask, cluster_id); > > > > Yeah, and there are many more. I'm currently sitting on a rather long > queue of GICv3-related 32bit patches. I'll try to get that posted shortly. I'll hold off until you post a complete series then. thx, Jason.
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 57eaa5a0b1e3..9e13c87c7dfe 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -441,7 +441,7 @@ static u16 gic_compute_target_list(int *base_cpu, const struct cpumask *mask, mpidr = cpu_logical_map(cpu); - if (cluster_id != (mpidr & ~0xffUL)) { + if (cluster_id != (mpidr & ~0xffULL)) { cpu--; goto out; } @@ -479,7 +479,7 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) smp_wmb(); for_each_cpu_mask(cpu, *mask) { - u64 cluster_id = cpu_logical_map(cpu) & ~0xffUL; + u64 cluster_id = cpu_logical_map(cpu) & ~0xffULL; u16 tlist; tlist = gic_compute_target_list(&cpu, mask, cluster_id);