| Message ID | 1352983614-22924-2-git-send-email-lorenzo.pieralisi@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Nov 15, 2012 at 12:46:50PM +0000, Lorenzo Pieralisi wrote: > This patch applies some basic changes to the smp_setup_processor_id() > ARM implementation to make the code that builds cpu_logical_map more > uniform across the kernel. > > The function now prints the full extent of the boot CPU MPIDR[23:0] and > initializes the cpu_logical_map for CPUs up to nr_cpu_ids. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > --- > arch/arm/kernel/setup.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > index da1d1aa..d0df6c8 100644 > --- a/arch/arm/kernel/setup.c > +++ b/arch/arm/kernel/setup.c > @@ -426,13 +426,14 @@ int __cpu_logical_map[NR_CPUS]; > void __init smp_setup_processor_id(void) > { > int i; > - u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0; > + u32 mpidr = is_smp() ? read_cpuid_mpidr() & 0xffffff : 0; > + u32 cpu = mpidr & 0xff; Can we move the #defines out of topology.c and use those instead of magic masks please? You could use MPIDR_HWID_BITMASK, although the LEVEL mask definitions over there don't look right to me (MPIDR_LEVEL0_MASK is 0x3?) Will
[CC'ed Vincent following MPIDR mask query] On Thu, Nov 15, 2012 at 01:49:51PM +0000, Will Deacon wrote: > On Thu, Nov 15, 2012 at 12:46:50PM +0000, Lorenzo Pieralisi wrote: > > This patch applies some basic changes to the smp_setup_processor_id() > > ARM implementation to make the code that builds cpu_logical_map more > > uniform across the kernel. > > > > The function now prints the full extent of the boot CPU MPIDR[23:0] and > > initializes the cpu_logical_map for CPUs up to nr_cpu_ids. > > > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > > --- > > arch/arm/kernel/setup.c | 7 ++++--- > > 1 file changed, 4 insertions(+), 3 deletions(-) > > > > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > > index da1d1aa..d0df6c8 100644 > > --- a/arch/arm/kernel/setup.c > > +++ b/arch/arm/kernel/setup.c > > @@ -426,13 +426,14 @@ int __cpu_logical_map[NR_CPUS]; > > void __init smp_setup_processor_id(void) > > { > > int i; > > - u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0; > > + u32 mpidr = is_smp() ? read_cpuid_mpidr() & 0xffffff : 0; > > + u32 cpu = mpidr & 0xff; > > Can we move the #defines out of topology.c and use those instead of magic > masks please? You could use MPIDR_HWID_BITMASK, although the LEVEL mask > definitions over there don't look right to me (MPIDR_LEVEL0_MASK is 0x3?) Yes, I should have done that, you are right. LEVEL0 and LEVEL1 masks look wrong to me. #define MPIDR_LEVEL0_MASK 0x3 #define MPIDR_LEVEL1_MASK 0xF Vincent, why are they defined with those values ? They should all be defined as 0xFF. I will fix them and move them to a header file. Thanks, Lorenzo
On 15 November 2012 15:18, Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> wrote: > [CC'ed Vincent following MPIDR mask query] > > On Thu, Nov 15, 2012 at 01:49:51PM +0000, Will Deacon wrote: >> On Thu, Nov 15, 2012 at 12:46:50PM +0000, Lorenzo Pieralisi wrote: >> > This patch applies some basic changes to the smp_setup_processor_id() >> > ARM implementation to make the code that builds cpu_logical_map more >> > uniform across the kernel. >> > >> > The function now prints the full extent of the boot CPU MPIDR[23:0] and >> > initializes the cpu_logical_map for CPUs up to nr_cpu_ids. >> > >> > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> >> > --- >> > arch/arm/kernel/setup.c | 7 ++++--- >> > 1 file changed, 4 insertions(+), 3 deletions(-) >> > >> > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c >> > index da1d1aa..d0df6c8 100644 >> > --- a/arch/arm/kernel/setup.c >> > +++ b/arch/arm/kernel/setup.c >> > @@ -426,13 +426,14 @@ int __cpu_logical_map[NR_CPUS]; >> > void __init smp_setup_processor_id(void) >> > { >> > int i; >> > - u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0; >> > + u32 mpidr = is_smp() ? read_cpuid_mpidr() & 0xffffff : 0; >> > + u32 cpu = mpidr & 0xff; >> >> Can we move the #defines out of topology.c and use those instead of magic >> masks please? You could use MPIDR_HWID_BITMASK, although the LEVEL mask >> definitions over there don't look right to me (MPIDR_LEVEL0_MASK is 0x3?) > > Yes, I should have done that, you are right. LEVEL0 and LEVEL1 masks look > wrong to me. > > #define MPIDR_LEVEL0_MASK 0x3 > #define MPIDR_LEVEL1_MASK 0xF > > Vincent, why are they defined with those values ? They should all be > defined as 0xFF. IIRC, These field are defined to 8bits width by default in the ARM ARM but the Cortex A-9 implementation reduced the usage to 2 bits for CPU ID and 4 bits for cluster ID. I had choose this implementation because it was the only one available at the moment. Now we might come back to the full width range Vincent > > I will fix them and move them to a header file. > > Thanks, > Lorenzo >
On Thu, 15 Nov 2012, Lorenzo Pieralisi wrote: > This patch applies some basic changes to the smp_setup_processor_id() > ARM implementation to make the code that builds cpu_logical_map more > uniform across the kernel. > > The function now prints the full extent of the boot CPU MPIDR[23:0] and > initializes the cpu_logical_map for CPUs up to nr_cpu_ids. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Acked-by: Nicolas Pitre <nico@linaro.org> > --- > arch/arm/kernel/setup.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > index da1d1aa..d0df6c8 100644 > --- a/arch/arm/kernel/setup.c > +++ b/arch/arm/kernel/setup.c > @@ -426,13 +426,14 @@ int __cpu_logical_map[NR_CPUS]; > void __init smp_setup_processor_id(void) > { > int i; > - u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0; > + u32 mpidr = is_smp() ? read_cpuid_mpidr() & 0xffffff : 0; > + u32 cpu = mpidr & 0xff; > > cpu_logical_map(0) = cpu; > - for (i = 1; i < NR_CPUS; ++i) > + for (i = 1; i < nr_cpu_ids; ++i) > cpu_logical_map(i) = i == cpu ? 0 : i; > > - printk(KERN_INFO "Booting Linux on physical CPU %d\n", cpu); > + printk(KERN_INFO "Booting Linux on physical CPU 0x%x\n", mpidr); > } > > static void __init setup_processor(void) > -- > 1.7.12 > >
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index da1d1aa..d0df6c8 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -426,13 +426,14 @@ int __cpu_logical_map[NR_CPUS]; void __init smp_setup_processor_id(void) { int i; - u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0; + u32 mpidr = is_smp() ? read_cpuid_mpidr() & 0xffffff : 0; + u32 cpu = mpidr & 0xff; cpu_logical_map(0) = cpu; - for (i = 1; i < NR_CPUS; ++i) + for (i = 1; i < nr_cpu_ids; ++i) cpu_logical_map(i) = i == cpu ? 0 : i; - printk(KERN_INFO "Booting Linux on physical CPU %d\n", cpu); + printk(KERN_INFO "Booting Linux on physical CPU 0x%x\n", mpidr); } static void __init setup_processor(void)
This patch applies some basic changes to the smp_setup_processor_id() ARM implementation to make the code that builds cpu_logical_map more uniform across the kernel. The function now prints the full extent of the boot CPU MPIDR[23:0] and initializes the cpu_logical_map for CPUs up to nr_cpu_ids. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> --- arch/arm/kernel/setup.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)