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version & get a new one if it's outdated, and a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

1 files changed, 18 insertions, 0 deletions

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);
+}