diff options
| -rw-r--r-- | arch/arm64/include/asm/kvm_mmu.h | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h index e3e793d0ec30..7e7f276bcdd0 100644 --- a/arch/arm64/include/asm/kvm_mmu.h +++ b/arch/arm64/include/asm/kvm_mmu.h @@ -56,11 +56,6 @@ /* * Convert a kernel VA into a HYP VA. * reg: VA to be converted. - * - * The actual code generation takes place in kvm_update_va_mask, and - * the instructions below are only there to reserve the space and - * perform the register allocation (kvm_update_va_mask uses the - * specific registers encoded in the instructions). */ .macro kern_hyp_va reg #ifndef __KVM_VHE_HYPERVISOR__ @@ -127,14 +122,29 @@ void kvm_apply_hyp_relocations(void); #define __hyp_pa(x) (((phys_addr_t)(x)) + hyp_physvirt_offset) +/* + * Convert a kernel VA into a HYP VA. + * + * Can be called from hyp or non-hyp context. + * + * The actual code generation takes place in kvm_update_va_mask(), and + * the instructions below are only there to reserve the space and + * perform the register allocation (kvm_update_va_mask() uses the + * specific registers encoded in the instructions). + */ static __always_inline unsigned long __kern_hyp_va(unsigned long v) { +/* + * This #ifndef is an optimisation for when this is called from VHE hyp + * context. When called from a VHE non-hyp context, kvm_update_va_mask() will + * replace the instructions with `nop`s. + */ #ifndef __KVM_VHE_HYPERVISOR__ - asm volatile(ALTERNATIVE_CB("and %0, %0, #1\n" - "ror %0, %0, #1\n" - "add %0, %0, #0\n" - "add %0, %0, #0, lsl 12\n" - "ror %0, %0, #63\n", + asm volatile(ALTERNATIVE_CB("and %0, %0, #1\n" /* mask with va_mask */ + "ror %0, %0, #1\n" /* rotate to the first tag bit */ + "add %0, %0, #0\n" /* insert the low 12 bits of the tag */ + "add %0, %0, #0, lsl 12\n" /* insert the top 12 bits of the tag */ + "ror %0, %0, #63\n", /* rotate back */ ARM64_ALWAYS_SYSTEM, kvm_update_va_mask) : "+r" (v)); |