[PATCH v2] riscv: make update_mmu_cache to support asid

Jinyu Tang
2022-09-04T13:40:16Z

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 supports asid. So add a new function
`flush_tlb_local_one_page` to flush local one page whether processor
supports asid or not,for cases that need to flush local one page like
function `update_mmu_cache`.

Signed-off-by: Jinyu Tang <tjytimi@163.com>
---
RFC V1 -> V2 :
1.Rebased on PATCH9 of IPI imporvement series as Anup Patel
suggestion.
2.Make commit log more clear.

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 27a7db8eb2c4..0843e1baaf34 100644
--- a/arch/riscv/mm/tlbflush.c
+++ b/arch/riscv/mm/tlbflush.c
@@ -41,6 +41,17 @@ static inline void local_flush_tlb_range_asid(unsigned long start,
local_flush_tlb_all_asid(asid);
}

+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);
+ }
+}
+
static void __ipi_flush_tlb_all(void *info)
{
local_flush_tlb_all();
--
2.30.2