kvm: remove dead code

The function kvm_io_bus_read_cookie is defined but never used
in current in-tree code.

Signed-off-by: Stephen Hemminger <[e-mail]>
Signed-off-by: Marcelo Tosatti <[e-mail]>

include/linux/kvm_host.h

···
 			    int len, const void *val, long cookie);
 int kvm_io_bus_read(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr, int len,
 		    void *val);
-int kvm_io_bus_read_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
-			   int len, void *val, long cookie);
 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
 			    int len, struct kvm_io_device *dev);
 int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx,

virt/kvm/kvm_main.c

···
 	return r < 0 ? r : 0;
 }
 
-/* kvm_io_bus_read_cookie - called under kvm->slots_lock */
-int kvm_io_bus_read_cookie(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
-			   int len, void *val, long cookie)
-{
-	struct kvm_io_bus *bus;
-	struct kvm_io_range range;
-
-	range = (struct kvm_io_range) {
-		.addr = addr,
-		.len = len,
-	};
-
-	bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
-
-	/* First try the device referenced by cookie. */
-	if ((cookie >= 0) && (cookie < bus->dev_count) &&
-	    (kvm_io_bus_cmp(&range, &bus->range[cookie]) == 0))
-		if (!kvm_iodevice_read(bus->range[cookie].dev, addr, len,
-				       val))
-			return cookie;
-
-	/*
-	 * cookie contained garbage; fall back to search and return the
-	 * correct cookie value.
-	 */
-	return __kvm_io_bus_read(bus, &range, val);
-}
 
 /* Caller must hold slots_lock. */
 int kvm_io_bus_register_dev(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,