From 42d5b846574f0904dbaf9dbdea4f19402589cddf Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Sat, 2 Feb 2019 01:43:25 +0000 Subject: [PATCH] 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ASID version checks Introduce a new check_mmu_context() function to check an mm's ASID version & get a new one if it's outdated, and a check_switch_mmu_context() function which additionally sets up the new ASID & page directory.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 Cc: linux-mips@vger.kernel.org --- arch/mips/include/asm/mmu_context.h | 8 +++----- arch/mips/kvm/trap_emul.c | 22 ++++------------------ arch/mips/kvm/vz.c | 6 +++--- arch/mips/mm/context.c | 18 ++++++++++++++++++ 4 files changed, 28 insertions(+), 26 deletions(-) diff --git a/arch/mips/include/asm/mmu_context.h b/arch/mips/include/asm/mmu_context.h index cb39a39d02f6..336682fb48de 100644 --- a/arch/mips/include/asm/mmu_context.h +++ b/arch/mips/include/asm/mmu_context.h @@ -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. diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c index 503c2fb7e4da..22ffe72a9e4b 100644 --- a/arch/mips/kvm/trap_emul.c +++ b/arch/mips/kvm/trap_emul.c @@ -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(); diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c index d98c12a22eac..dde20887a70d 100644 --- a/arch/mips/kvm/vz.c +++ b/arch/mips/kvm/vz.c @@ -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); } } diff --git a/arch/mips/mm/context.c b/arch/mips/mm/context.c index b5af471006f0..4dd976acf41d 100644 --- a/arch/mips/mm/context.c +++ b/arch/mips/mm/context.c @@ -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); +}