MIPS: mm: Unify ASID version checks

Introduce a new check_mmu_context() function to check an mm's ASID
version & get a new one if it's outdated, and a
check_switch_mmu_context() function which additionally sets up the new
ASID & page directory. Simplify switch_mm() & various
get_new_mmu_context() callsites in MIPS KVM by making use of the new
functions, which will help reduce the amount of code that requires
modification to gain MMID support.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
This commit is contained in:
Paul Burton 2019-02-02 01:43:25 +00:00
parent 4ebea49ce2
commit 42d5b84657
No known key found for this signature in database
GPG Key ID: 3EA79FACB57500DD
4 changed files with 28 additions and 26 deletions

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@ -98,6 +98,8 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
}
extern void get_new_mmu_context(struct mm_struct *mm);
extern void check_mmu_context(struct mm_struct *mm);
extern void check_switch_mmu_context(struct mm_struct *mm);
/*
* Initialize the context related info for a new mm_struct
@ -126,11 +128,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
local_irq_save(flags);
htw_stop();
/* Check if our ASID is of an older version and thus invalid */
if ((cpu_context(cpu, next) ^ asid_cache(cpu)) & asid_version_mask(cpu))
get_new_mmu_context(next);
write_c0_entryhi(cpu_asid(cpu, next));
TLBMISS_HANDLER_SETUP_PGD(next->pgd);
check_switch_mmu_context(next);
/*
* Mark current->active_mm as not "active" anymore.

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@ -1056,11 +1056,7 @@ static int kvm_trap_emul_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
*/
if (current->flags & PF_VCPU) {
mm = KVM_GUEST_KERNEL_MODE(vcpu) ? kern_mm : user_mm;
if ((cpu_context(cpu, mm) ^ asid_cache(cpu)) &
asid_version_mask(cpu))
get_new_mmu_context(mm);
write_c0_entryhi(cpu_asid(cpu, mm));
TLBMISS_HANDLER_SETUP_PGD(mm->pgd);
check_switch_mmu_context(mm);
kvm_mips_suspend_mm(cpu);
ehb();
}
@ -1074,11 +1070,7 @@ static int kvm_trap_emul_vcpu_put(struct kvm_vcpu *vcpu, int cpu)
if (current->flags & PF_VCPU) {
/* Restore normal Linux process memory map */
if (((cpu_context(cpu, current->mm) ^ asid_cache(cpu)) &
asid_version_mask(cpu)))
get_new_mmu_context(current->mm);
write_c0_entryhi(cpu_asid(cpu, current->mm));
TLBMISS_HANDLER_SETUP_PGD(current->mm->pgd);
check_switch_mmu_context(current->mm);
kvm_mips_resume_mm(cpu);
ehb();
}
@ -1228,9 +1220,7 @@ static void kvm_trap_emul_vcpu_reenter(struct kvm_run *run,
* Check if ASID is stale. This may happen due to a TLB flush request or
* a lazy user MM invalidation.
*/
if ((cpu_context(cpu, mm) ^ asid_cache(cpu)) &
asid_version_mask(cpu))
get_new_mmu_context(mm);
check_mmu_context(mm);
}
static int kvm_trap_emul_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
@ -1266,11 +1256,7 @@ static int kvm_trap_emul_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
cpu = smp_processor_id();
/* Restore normal Linux process memory map */
if (((cpu_context(cpu, current->mm) ^ asid_cache(cpu)) &
asid_version_mask(cpu)))
get_new_mmu_context(current->mm);
write_c0_entryhi(cpu_asid(cpu, current->mm));
TLBMISS_HANDLER_SETUP_PGD(current->mm->pgd);
check_switch_mmu_context(current->mm);
kvm_mips_resume_mm(cpu);
htw_start();

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@ -2454,10 +2454,10 @@ static void kvm_vz_vcpu_load_tlb(struct kvm_vcpu *vcpu, int cpu)
* Root ASID dealiases guest GPA mappings in the root TLB.
* Allocate new root ASID if needed.
*/
if (cpumask_test_and_clear_cpu(cpu, &kvm->arch.asid_flush_mask)
|| (cpu_context(cpu, gpa_mm) ^ asid_cache(cpu)) &
asid_version_mask(cpu))
if (cpumask_test_and_clear_cpu(cpu, &kvm->arch.asid_flush_mask))
get_new_mmu_context(gpa_mm);
else
check_mmu_context(gpa_mm);
}
}

View File

@ -17,3 +17,21 @@ void get_new_mmu_context(struct mm_struct *mm)
cpu_context(cpu, mm) = asid_cache(cpu) = asid;
}
void check_mmu_context(struct mm_struct *mm)
{
unsigned int cpu = smp_processor_id();
/* Check if our ASID is of an older version and thus invalid */
if ((cpu_context(cpu, mm) ^ asid_cache(cpu)) & asid_version_mask(cpu))
get_new_mmu_context(mm);
}
void check_switch_mmu_context(struct mm_struct *mm)
{
unsigned int cpu = smp_processor_id();
check_mmu_context(mm);
write_c0_entryhi(cpu_asid(cpu, mm));
TLBMISS_HANDLER_SETUP_PGD(mm->pgd);
}