diff options
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/kvm/hyp/hyp.h | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h index 080965348def..73419a769112 100644 --- a/arch/arm64/kvm/hyp/hyp.h +++ b/arch/arm64/kvm/hyp/hyp.h @@ -29,6 +29,30 @@ #define hyp_kern_va(v) (typeof(v))((unsigned long)(v) - HYP_PAGE_OFFSET \ + PAGE_OFFSET) +/** + * hyp_alternate_select - Generates patchable code sequences that are + * used to switch between two implementations of a function, depending + * on the availability of a feature. + * + * @fname: a symbol name that will be defined as a function returning a + * function pointer whose type will match @orig and @alt + * @orig: A pointer to the default function, as returned by @fname when + * @cond doesn't hold + * @alt: A pointer to the alternate function, as returned by @fname + * when @cond holds + * @cond: a CPU feature (as described in asm/cpufeature.h) + */ +#define hyp_alternate_select(fname, orig, alt, cond) \ +typeof(orig) * __hyp_text fname(void) \ +{ \ + typeof(alt) *val = orig; \ + asm volatile(ALTERNATIVE("nop \n", \ + "mov %0, %1 \n", \ + cond) \ + : "+r" (val) : "r" (alt)); \ + return val; \ +} + void __vgic_v2_save_state(struct kvm_vcpu *vcpu); void __vgic_v2_restore_state(struct kvm_vcpu *vcpu); |