Add copyin32 implementation.

ok guenther@

diff --git a/sys/arch/arm64/arm64/copy.S b/sys/arch/arm64/arm64/copy.S
index 0a493cc..af9f015 100644 (file)
--- a/sys/arch/arm64/arm64/copy.S
+++ b/sys/arch/arm64/arm64/copy.S
@@ -1,4 +1,4 @@
-/* $OpenBSD: copy.S,v 1.3 2017/02/15 21:39:50 patrick Exp $ */
+/* $OpenBSD: copy.S,v 1.4 2017/12/30 10:20:34 kettenis Exp $ */
 /*
  * Copyright (c) 2015 Dale Rahn <drahn@dalerahn.com>
  * Copyright (c) 2014 Patrick Wildt <patrick@blueri.se>
@@ -60,6 +60,28 @@ ENTRY(copyin)
        ldr     x4, [x3, #(PCB_ONFAULT)]
        ret
 
+/*
+ * x0 = user space address
+ * x1 = kernel space address
+ *
+ * Atomically copies a 32-bit word from user space to kernel space
+ *
+ * XXX should this assert that address spaces are correct for each address?
+ */
+ENTRY(copyin32)
+       mrs     x3, tpidr_el1                   // load cpuinfo
+       ldr     x3, [x3, #(CI_CURPCB)]
+       ldr     x4, [x3, #(PCB_ONFAULT)]
+       adr     x5, .Lcopyfault
+       str     x5, [x3, #(PCB_ONFAULT)]        // set handler
+
+       ldtr    w6, [x0]
+       str     w6, [x1]
+
+       str     x4, [x3, #(PCB_ONFAULT)]        // clear handler
+       mov     x0, xzr
+       ret
+
 /*
  * x0 = kernel space address
  * x1 = user space address