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Unverified Commit 42d5b846 authored by Paul Burton's avatar Paul Burton
Browse files

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version & get a new one if it's outdated, and a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: default avatarPaul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
parent 4ebea49c

arch/mips/include/asm/mmu_context.h

+3 −5
Original line number Diff line number Diff line
@@ -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.

arch/mips/kvm/trap_emul.c

+4 −18
Original line number Diff line number Diff line
@@ -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();

arch/mips/kvm/vz.c

+3 −3
Original line number Diff line number Diff line
@@ -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);

	}

}

arch/mips/mm/context.c

+18 −0
Original line number Diff line number Diff line
@@ -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);

}