On Thu, May 16, 2013 at 04:34:07PM +0100, Lorenzo Pieralisi wrote: > For legacy reasons, the __cpu_logical_map array is initialized to 0. > On old pre-DT ARM platforms, smp_setup_processor_id() generates > __cpu_logical_map entries at boot before the number of possible CPUs is > set-up, with values that can be considered valid MPIDRs even if they are > not present in the system booting; this implies that the __cpu_logical_map[] > might end up containing MPIDR values that can be considered valid at logical > indexes corresponding to CPUs that are not marked as possible. > > To prevent issues with the current implementation, this patch defines an > MPIDR_INVALID value, statically initializes the __cpu_logical_map[] array to > it > and allows DT parsing code to overwrite values in the __cpu_logical_map array > that were erroneously set-up in smp_setup_processor_id().
What issues have you actually hit with this? > Signed-off-by: Lorenzo Pieralisi <[email protected]> > CC: Will Deacon <[email protected]> > --- > arch/arm/include/asm/cputype.h | 2 ++ > arch/arm/include/asm/smp_plat.h | 2 +- > arch/arm/kernel/devtree.c | 10 ++++++---- > arch/arm/kernel/setup.c | 2 +- > 4 files changed, 10 insertions(+), 6 deletions(-) > > diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h > index 7652712..dba62cb 100644 > --- a/arch/arm/include/asm/cputype.h > +++ b/arch/arm/include/asm/cputype.h > @@ -32,6 +32,8 @@ > > #define MPIDR_HWID_BITMASK 0xFFFFFF > > +#define MPIDR_INVALID (~MPIDR_HWID_BITMASK) > + > #define MPIDR_LEVEL_BITS 8 > #define MPIDR_LEVEL_MASK ((1 << MPIDR_LEVEL_BITS) - 1) > > diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h > index aaa61b6..e789832 100644 > --- a/arch/arm/include/asm/smp_plat.h > +++ b/arch/arm/include/asm/smp_plat.h > @@ -49,7 +49,7 @@ static inline int cache_ops_need_broadcast(void) > /* > * Logical CPU mapping. > */ > -extern int __cpu_logical_map[]; > +extern u32 __cpu_logical_map[]; > #define cpu_logical_map(cpu) __cpu_logical_map[cpu] > /* > * Retrieve logical cpu index corresponding to a given MPIDR[23:0] > diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c > index d2293c0..08f012e 100644 > --- a/arch/arm/kernel/devtree.c > +++ b/arch/arm/kernel/devtree.c > @@ -79,12 +79,12 @@ void __init arm_dt_init_cpu_maps(void) > * read as 0. > */ > static u32 tmp_map[NR_CPUS] __initdata = { > - [0 ... NR_CPUS-1] = UINT_MAX }; > + [0 ... NR_CPUS-1] = MPIDR_INVALID }; > struct device_node *cpu, *cpus; > u32 i, j, cpuidx = 1; > u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0; > - > bool bootcpu_valid = false; > + Random whitespace change. Will _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
