uml/x86: use x86 load_unaligned_zeropad()

allows, among other things, to drop !DCACHE_WORD_ACCESS mess in
x86 csum-partial_64.c

Signed-off-by: Al Viro <[e-mail]>

arch/um/include/asm/Kbuild

···
 generic-y += switch_to.h
 generic-y += topology.h
 generic-y += trace_clock.h
-generic-y += word-at-a-time.h
 generic-y += kprobes.h
 generic-y += mm_hooks.h
 generic-y += vga.h

arch/x86/lib/csum-partial_64.c

···
 		buff += 8;
 	}
 	if (len & 7) {
-#ifdef CONFIG_DCACHE_WORD_ACCESS
 		unsigned int shift = (8 - (len & 7)) * 8;
 		unsigned long trail;
 
···
 		    "adcq $0,%[res]"
 			: [res] "+r" (temp64)
 			: [trail] "r" (trail));
-#else
-		if (len & 4) {
-			asm("addq %[val],%[res]\n\t"
-			    "adcq $0,%[res]"
-				: [res] "+r" (temp64)
-				: [val] "r" ((u64)*(u32 *)buff)
-				: "memory");
-			buff += 4;
-		}
-		if (len & 2) {
-			asm("addq %[val],%[res]\n\t"
-			    "adcq $0,%[res]"
-				: [res] "+r" (temp64)
-				: [val] "r" ((u64)*(u16 *)buff)
-				: "memory");
-			buff += 2;
-		}
-		if (len & 1) {
-			asm("addq %[val],%[res]\n\t"
-			    "adcq $0,%[res]"
-				: [res] "+r" (temp64)
-				: [val] "r" ((u64)*(u8 *)buff)
-				: "memory");
-		}
-#endif
 	}
 	result = add32_with_carry(temp64 >> 32, temp64 & 0xffffffff);
 	if (unlikely(odd)) {

arch/x86/um/Kconfig

···
 
 config UML_X86
 	def_bool y
+	select DCACHE_WORD_ACCESS
 
 config 64BIT
 	bool "64-bit kernel" if "$(SUBARCH)" = "x86"