2022-12-07 14:21:56

by Huacai Chen

[permalink] [raw]
Subject: [PATCH] LoongArch: mm: Fix huge page entry update for virtual machine

In virtual machine (guest mode), the tlbwr instruction can not write the
last entry of MTLB, so we need to make it non-present by invtlb and then
write it by tlbfill. This also simplify the whole logic.

Signed-off-by: Rui Wang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
---
arch/loongarch/mm/tlbex.S | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/arch/loongarch/mm/tlbex.S b/arch/loongarch/mm/tlbex.S
index d8ee8fbc8c67..58781c6e4191 100644
--- a/arch/loongarch/mm/tlbex.S
+++ b/arch/loongarch/mm/tlbex.S
@@ -10,6 +10,8 @@
#include <asm/regdef.h>
#include <asm/stackframe.h>

+#define INVTLB_ADDR_GFALSE_AND_ASID 5
+
#define PTRS_PER_PGD_BITS (PAGE_SHIFT - 3)
#define PTRS_PER_PUD_BITS (PAGE_SHIFT - 3)
#define PTRS_PER_PMD_BITS (PAGE_SHIFT - 3)
@@ -136,13 +138,10 @@ tlb_huge_update_load:
ori t0, ra, _PAGE_VALID
st.d t0, t1, 0
#endif
- tlbsrch
- addu16i.d t1, zero, -(CSR_TLBIDX_EHINV >> 16)
- addi.d ra, t1, 0
- csrxchg ra, t1, LOONGARCH_CSR_TLBIDX
- tlbwr
-
- csrxchg zero, t1, LOONGARCH_CSR_TLBIDX
+ csrrd ra, LOONGARCH_CSR_ASID
+ csrrd t1, LOONGARCH_CSR_BADV
+ andi ra, ra, CSR_ASID_ASID
+ invtlb INVTLB_ADDR_GFALSE_AND_ASID, ra, t1

/*
* A huge PTE describes an area the size of the
@@ -287,13 +286,11 @@ tlb_huge_update_store:
ori t0, ra, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
st.d t0, t1, 0
#endif
- tlbsrch
- addu16i.d t1, zero, -(CSR_TLBIDX_EHINV >> 16)
- addi.d ra, t1, 0
- csrxchg ra, t1, LOONGARCH_CSR_TLBIDX
- tlbwr
+ csrrd ra, LOONGARCH_CSR_ASID
+ csrrd t1, LOONGARCH_CSR_BADV
+ andi ra, ra, CSR_ASID_ASID
+ invtlb INVTLB_ADDR_GFALSE_AND_ASID, ra, t1

- csrxchg zero, t1, LOONGARCH_CSR_TLBIDX
/*
* A huge PTE describes an area the size of the
* configured huge page size. This is twice the
@@ -436,6 +433,11 @@ tlb_huge_update_modify:
ori t0, ra, (_PAGE_VALID | _PAGE_DIRTY | _PAGE_MODIFIED)
st.d t0, t1, 0
#endif
+ csrrd ra, LOONGARCH_CSR_ASID
+ csrrd t1, LOONGARCH_CSR_BADV
+ andi ra, ra, CSR_ASID_ASID
+ invtlb INVTLB_ADDR_GFALSE_AND_ASID, ra, t1
+
/*
* A huge PTE describes an area the size of the
* configured huge page size. This is twice the
@@ -466,7 +468,7 @@ tlb_huge_update_modify:
addu16i.d t1, zero, (PS_HUGE_SIZE << (CSR_TLBIDX_PS_SHIFT - 16))
csrxchg t1, t0, LOONGARCH_CSR_TLBIDX

- tlbwr
+ tlbfill

/* Reset default page size */
addu16i.d t0, zero, (CSR_TLBIDX_PS >> 16)
--
2.31.1