On 09/22/2015 08:08 PM, Paul Burton wrote: > MAARs should be initialised on each CPU (or rather, core) in the system > in order to achieve consistent behaviour & performance. Previously they > have only been initialised on the boot CPU which leads to performance > problems if tasks are later scheduled on a secondary CPU, particularly > if those tasks make use of unaligned vector accesses where some CPUs > don't handle any cases in hardware for non-speculative memory regions. > Fix this by recording the MAAR configuration from the boot CPU and > applying it to secondary CPUs as part of their bringup. > > Reported-by: Doug Gilmore <doug.gilmore@xxxxxxxxxx> > Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx> > --- > > arch/mips/include/asm/maar.h | 9 +++++++++ > arch/mips/kernel/smp.c | 2 ++ > arch/mips/mm/init.c | 28 +++++++++++++++++++++++++--- > 3 files changed, 36 insertions(+), 3 deletions(-) > > diff --git a/arch/mips/include/asm/maar.h b/arch/mips/include/asm/maar.h > index b02891f..21d9607 100644 > --- a/arch/mips/include/asm/maar.h > +++ b/arch/mips/include/asm/maar.h > @@ -66,6 +66,15 @@ static inline void write_maar_pair(unsigned idx, phys_addr_t lower, > } > > /** > + * maar_init() - initialise MAARs > + * > + * Performs initialisation of MAARs for the current CPU, making use of the > + * platforms implementation of platform_maar_init where necessary and > + * duplicating the setup it provides on secondary CPUs. > + */ > +extern void maar_init(void); > + > +/** > * struct maar_config - MAAR configuration data > * @lower: The lowest address that the MAAR pair will affect. Must be > * aligned to a 2^16 byte boundary. > diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c > index a31896c..bd4385a 100644 > --- a/arch/mips/kernel/smp.c > +++ b/arch/mips/kernel/smp.c > @@ -42,6 +42,7 @@ > #include <asm/mmu_context.h> > #include <asm/time.h> > #include <asm/setup.h> > +#include <asm/maar.h> > > cpumask_t cpu_callin_map; /* Bitmask of started secondaries */ > > @@ -157,6 +158,7 @@ asmlinkage void start_secondary(void) > mips_clockevent_init(); > mp_ops->init_secondary(); > cpu_report(); > + maar_init(); > Hi, This breaks the ip27_defconfig in both upstream-sfr and linux-next arch/mips/built-in.o: In function `start_secondary': (.text+0x123e4): undefined reference to `maar_init' Makefile:944: recipe for target 'vmlinux' failed -- markos
