[PATCH V3 05/14] KVM: MIPS: Use lddir/ldpte instructions to lookup gpa_mm.pgd

[Huacai Chen]

Loongson-3 can use lddir/ldpte instuctions to accelerate page table
walking, so use them to lookup gpa_mm.pgd.

Signed-off-by: Huacai Chen <address@hidden>
Co-developed-by: Jiaxun Yang <address@hidden>
---
 arch/mips/kvm/entry.c | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/arch/mips/kvm/entry.c b/arch/mips/kvm/entry.c
index 16e1c93..fd71694 100644
--- a/arch/mips/kvm/entry.c
+++ b/arch/mips/kvm/entry.c
@@ -56,6 +56,7 @@
 #define C0_BADVADDR    8, 0
 #define C0_BADINSTR    8, 1
 #define C0_BADINSTRP   8, 2
+#define C0_PGD         9, 7
 #define C0_ENTRYHI     10, 0
 #define C0_GUESTCTL1   10, 4
 #define C0_STATUS      12, 0
@@ -307,7 +308,10 @@ static void *kvm_mips_build_enter_guest(void *addr)
 
 #ifdef CONFIG_KVM_MIPS_VZ
        /* Save normal linux process pgd (VZ guarantees pgd_reg is set) */
-       UASM_i_MFC0(&p, K0, c0_kscratch(), pgd_reg);
+       if (cpu_has_ldpte)
+               UASM_i_MFC0(&p, K0, C0_PWBASE);
+       else
+               UASM_i_MFC0(&p, K0, c0_kscratch(), pgd_reg);
        UASM_i_SW(&p, K0, offsetof(struct kvm_vcpu_arch, host_pgd), K1);
 
        /*
@@ -469,8 +473,10 @@ void *kvm_mips_build_tlb_refill_exception(void *addr, void 
*handler)
        u32 *p = addr;
        struct uasm_label labels[2];
        struct uasm_reloc relocs[2];
+#ifndef CONFIG_CPU_LOONGSON64
        struct uasm_label *l = labels;
        struct uasm_reloc *r = relocs;
+#endif
 
        memset(labels, 0, sizeof(labels));
        memset(relocs, 0, sizeof(relocs));
@@ -490,6 +496,16 @@ void *kvm_mips_build_tlb_refill_exception(void *addr, void 
*handler)
         */
        preempt_disable();
 
+#ifdef CONFIG_CPU_LOONGSON64
+       UASM_i_MFC0(&p, K1, C0_PGD);
+       uasm_i_lddir(&p, K0, K1, 3);  /* global page dir */
+#ifndef __PAGETABLE_PMD_FOLDED
+       uasm_i_lddir(&p, K1, K0, 1);  /* middle page dir */
+#endif
+       uasm_i_ldpte(&p, K1, 0);      /* even */
+       uasm_i_ldpte(&p, K1, 1);      /* odd */
+       uasm_i_tlbwr(&p);
+#else
        /*
         * Now for the actual refill bit. A lot of this can be common with the
         * Linux TLB refill handler, however we don't need to handle so many
@@ -512,6 +528,7 @@ void *kvm_mips_build_tlb_refill_exception(void *addr, void 
*handler)
        build_get_ptep(&p, K0, K1);
        build_update_entries(&p, K0, K1);
        build_tlb_write_entry(&p, &l, &r, tlb_random);
+#endif
 
        preempt_enable();
 
-- 
2.7.0