| Message ID | 20201124155039.13804-14-will@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | An alternative series for asymmetric AArch32 systems | expand |
On 11/24/20 15:50, Will Deacon wrote: > Provide an implementation of arch_task_cpu_possible_mask() so that we > can prevent 64-bit-only cores being added to the 'cpus_mask' for compat > tasks on systems with mismatched 32-bit support at EL0, > > Signed-off-by: Will Deacon <will@kernel.org> > --- > arch/arm64/include/asm/mmu_context.h | 13 +++++++++++++ > 1 file changed, 13 insertions(+) > > diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h > index 0672236e1aea..641dff35a56f 100644 > --- a/arch/arm64/include/asm/mmu_context.h > +++ b/arch/arm64/include/asm/mmu_context.h nit: wouldn't cpufeature.h be a better header? No strong opinion really, it just looked weird to see this among memory management related code. Cheers -- Qais Yousef > @@ -251,6 +251,19 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next, > #define deactivate_mm(tsk,mm) do { } while (0) > #define activate_mm(prev,next) switch_mm(prev, next, current) > > +static inline const struct cpumask * > +arch_task_cpu_possible_mask(struct task_struct *p) > +{ > + if (!static_branch_unlikely(&arm64_mismatched_32bit_el0)) > + return cpu_possible_mask; > + > + if (!is_compat_thread(task_thread_info(p))) > + return cpu_possible_mask; > + > + return system_32bit_el0_cpumask(); > +} > +#define arch_task_cpu_possible_mask arch_task_cpu_possible_mask > + > void verify_cpu_asid_bits(void); > void post_ttbr_update_workaround(void); > > -- > 2.29.2.454.gaff20da3a2-goog >
diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index 0672236e1aea..641dff35a56f 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -251,6 +251,19 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next, #define deactivate_mm(tsk,mm) do { } while (0) #define activate_mm(prev,next) switch_mm(prev, next, current) +static inline const struct cpumask * +arch_task_cpu_possible_mask(struct task_struct *p) +{ + if (!static_branch_unlikely(&arm64_mismatched_32bit_el0)) + return cpu_possible_mask; + + if (!is_compat_thread(task_thread_info(p))) + return cpu_possible_mask; + + return system_32bit_el0_cpumask(); +} +#define arch_task_cpu_possible_mask arch_task_cpu_possible_mask + void verify_cpu_asid_bits(void); void post_ttbr_update_workaround(void);
Provide an implementation of arch_task_cpu_possible_mask() so that we can prevent 64-bit-only cores being added to the 'cpus_mask' for compat tasks on systems with mismatched 32-bit support at EL0, Signed-off-by: Will Deacon <will@kernel.org> --- arch/arm64/include/asm/mmu_context.h | 13 +++++++++++++ 1 file changed, 13 insertions(+)