[RFC PATCH v1] riscv: make update_mmu_cache to support asid

[Jinyu Tang]

The `update_mmu_cache` function in riscv flush tlb cache without asid
information now, which will flush tlbs in other tasks' address space
even if processor support asid. So add a new function
`flush_tlb_local_one_page` to flush local one page whether processor
supports asid or not. If asid is supported, this function will use it.

Signed-off-by: Jinyu Tang <tjytimi at 163.com>
---
 arch/riscv/include/asm/pgtable.h  |  2 +-
 arch/riscv/include/asm/tlbflush.h |  2 ++
 arch/riscv/mm/tlbflush.c          | 11 +++++++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 7ec936910a96..09ccefa6b6c7 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -415,7 +415,7 @@ static inline void update_mmu_cache(struct vm_area_struct *vma,
 	 * Relying on flush_tlb_fix_spurious_fault would suffice, but
 	 * the extra traps reduce performance.  So, eagerly SFENCE.VMA.
 	 */
-	local_flush_tlb_page(address);
+	flush_tlb_local_one_page(vma, address);
 }
 
 static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index 801019381dea..120aeb1c6ecf 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -30,6 +30,7 @@ static inline void local_flush_tlb_page(unsigned long addr)
 #if defined(CONFIG_SMP) && defined(CONFIG_MMU)
 void flush_tlb_all(void);
 void flush_tlb_mm(struct mm_struct *mm);
+void flush_tlb_local_one_page(struct vm_area_struct *vma, unsigned long addr);
 void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr);
 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 		     unsigned long end);
@@ -42,6 +43,7 @@ void flush_pmd_tlb_range(struct vm_area_struct *vma, unsigned long start,
 
 #define flush_tlb_all() local_flush_tlb_all()
 #define flush_tlb_page(vma, addr) local_flush_tlb_page(addr)
+#define flush_tlb_local_one_page(vma, addr) local_flush_tlb_page(addr)
 
 static inline void flush_tlb_range(struct vm_area_struct *vma,
 		unsigned long start, unsigned long end)
diff --git a/arch/riscv/mm/tlbflush.c b/arch/riscv/mm/tlbflush.c
index 37ed760d007c..a2634ce55626 100644
--- a/arch/riscv/mm/tlbflush.c
+++ b/arch/riscv/mm/tlbflush.c
@@ -64,6 +64,17 @@ static void __sbi_tlb_flush_range(struct mm_struct *mm, unsigned long start,
 	put_cpu();
 }
 
+void flush_tlb_local_one_page(struct vm_area_struct *vma, unsigned long addr)
+{
+	if (static_branch_unlikely(&use_asid_allocator)) {
+		unsigned long asid = atomic_long_read(&vma->vm_mm->context.id);
+
+		local_flush_tlb_page_asid(addr, asid);
+	} else {
+		local_flush_tlb_page(addr);
+	}
+}
+
 void flush_tlb_mm(struct mm_struct *mm)
 {
 	__sbi_tlb_flush_range(mm, 0, -1, PAGE_SIZE);
-- 
2.30.2