On Fri, Jul 03, 2015 at 07:39:13PM +0200, Paolo Bonzini wrote:
>
>
> On 25/06/2015 20:45, Andrew Jones wrote:
> > The mmu is enabled automatically for all cpus, they must disable it
> > themselves if they don't want it on. Switch from managing a cpumask
> > of enabled cpus to one of disabled cpus. This allows us to remove
> > the mmu_set_enabled call from secondary_cinit, and the function all
> > together.
> >
> > Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
> > ---
> > lib/arm/asm/mmu-api.h | 1 -
> > lib/arm/mmu.c | 21 ++++++++++-----------
> > lib/arm/smp.c | 1 -
> > 3 files changed, 10 insertions(+), 13 deletions(-)
> >
> > diff --git a/lib/arm/asm/mmu-api.h b/lib/arm/asm/mmu-api.h
> > index c46c4b08b14cc..12fdc57918c27 100644
> > --- a/lib/arm/asm/mmu-api.h
> > +++ b/lib/arm/asm/mmu-api.h
> > @@ -2,7 +2,6 @@
> > #define __ASMARM_MMU_API_H_
> > extern pgd_t *mmu_idmap;
> > extern bool mmu_enabled(void);
> > -extern void mmu_set_enabled(void);
> > extern void mmu_enable(pgd_t *pgtable);
> > extern void mmu_disable(void);
> > extern void mmu_enable_idmap(void);
> > diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c
> > index 5966b408cb455..ad558e177dd1c 100644
> > --- a/lib/arm/mmu.c
> > +++ b/lib/arm/mmu.c
> > @@ -14,32 +14,31 @@ extern unsigned long etext;
> >
> > pgd_t *mmu_idmap;
> >
> > -static cpumask_t mmu_enabled_cpumask;
> > +static cpumask_t mmu_disabled_cpumask;
> > +
> > bool mmu_enabled(void)
> > {
> > - struct thread_info *ti = current_thread_info();
> > - return cpumask_test_cpu(ti->cpu, &mmu_enabled_cpumask);
> > -}
> > + int cpu = current_thread_info()->cpu;
> >
> > -void mmu_set_enabled(void)
> > -{
> > - struct thread_info *ti = current_thread_info();
> > - cpumask_set_cpu(ti->cpu, &mmu_enabled_cpumask);
> > + return !cpumask_test_cpu(cpu, &mmu_disabled_cpumask);
> > }
> >
> > extern void asm_mmu_enable(phys_addr_t pgtable);
> > void mmu_enable(pgd_t *pgtable)
> > {
> > + int cpu = current_thread_info()->cpu;
> > +
> > asm_mmu_enable(__pa(pgtable));
> > flush_tlb_all();
> > - mmu_set_enabled();
> > + cpumask_clear_cpu(cpu, &mmu_disabled_cpumask);
> > }
> >
> > extern void asm_mmu_disable(void);
> > void mmu_disable(void)
> > {
> > - struct thread_info *ti = current_thread_info();
> > - cpumask_clear_cpu(ti->cpu, &mmu_enabled_cpumask);
> > + int cpu = current_thread_info()->cpu;
> > +
> > + cpumask_set_cpu(cpu, &mmu_disabled_cpumask);
> > asm_mmu_disable();
> > }
> >
> > diff --git a/lib/arm/smp.c b/lib/arm/smp.c
> > index f389ba6598faa..ca435dcd5f4a2 100644
> > --- a/lib/arm/smp.c
> > +++ b/lib/arm/smp.c
> > @@ -23,7 +23,6 @@ secondary_entry_fn secondary_cinit(void)
> > secondary_entry_fn entry;
> >
> > thread_info_init(ti, 0);
> > - mmu_set_enabled();
> >
> > /*
> > * Save secondary_data.entry locally to avoid opening a race
> >
>
> This is needed too on a Cubietruck:
Oh right! We definitely need to return false from mmu_enabled
for cubietruck on early boot (that was the whole reason to
introduce mmu_enabled()). Thanks for fixing it up!
>
> diff --git a/lib/arm/asm/mmu-api.h b/lib/arm/asm/mmu-api.h
> index 12fdc57..73bac70 100644
> --- a/lib/arm/asm/mmu-api.h
> +++ b/lib/arm/asm/mmu-api.h
> @@ -3,6 +3,7 @@
> extern pgd_t *mmu_idmap;
> extern bool mmu_enabled(void);
> extern void mmu_enable(pgd_t *pgtable);
> +extern void mmu_mark_disabled(int cpu);
> extern void mmu_disable(void);
> extern void mmu_enable_idmap(void);
> extern void mmu_init_io_sect(pgd_t *pgtable, unsigned long virt_offset);
> diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c
> index ad558e1..8ff659b 100644
> --- a/lib/arm/mmu.c
> +++ b/lib/arm/mmu.c
> @@ -14,7 +14,8 @@ extern unsigned long etext;
>
> pgd_t *mmu_idmap;
>
> -static cpumask_t mmu_disabled_cpumask;
> +/* CPU 0 starts with disabled MMU */
> +static cpumask_t mmu_disabled_cpumask = { {1} };
>
> bool mmu_enabled(void)
> {
> @@ -33,6 +34,11 @@ void mmu_enable(pgd_t *pgtable)
> cpumask_clear_cpu(cpu, &mmu_disabled_cpumask);
> }
>
> +void mmu_mark_disabled(int cpu)
> +{
> + cpumask_set_cpu(cpu, &mmu_disabled_cpumask);
> +}
> +
> extern void asm_mmu_disable(void);
> void mmu_disable(void)
> {
> diff --git a/lib/arm/psci.c b/lib/arm/psci.c
> index aca8885..c4469c9 100644
> --- a/lib/arm/psci.c
> +++ b/lib/arm/psci.c
> @@ -9,6 +9,7 @@
> #include <asm/psci.h>
> #include <asm/setup.h>
> #include <asm/page.h>
> +#include <asm/mmu-api.h>
>
> #define T PSCI_INVOKE_ARG_TYPE
> __attribute__((noinline))
> @@ -29,6 +30,7 @@ int psci_cpu_on(unsigned long cpuid, unsigned long
> entry_point)
> extern void secondary_entry(void);
> int cpu_psci_cpu_boot(unsigned int cpu)
> {
> + mmu_mark_disabled(cpu);
> int err = psci_cpu_on(cpus[cpu], __pa(secondary_entry));
> if (err)
> printf("failed to boot CPU%d (%d)\n", cpu, err);
> --
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