x86/xen: Remove .fixup usage

Employ the fancy new EX_TYPE_IMM_REG to store -EFAULT in the return
register and use this to remove some Xen .fixup usage.

All callers of these functions only test for 0 return, so the actual
return value change from -1 to -EFAULT is immaterial.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20211110101325.545019822@infradead.org

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 1a162e5..e989bc2 100644 (file)
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -96,11 +96,7 @@ static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
 
        asm volatile("1: mov %[val], %[ptr]\n"
                     "2:\n"
-                    ".section .fixup, \"ax\"\n"
-                    "3: sub $1, %[ret]\n"
-                    "   jmp 2b\n"
-                    ".previous\n"
-                    _ASM_EXTABLE(1b, 3b)
+                    _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %[ret])
                     : [ret] "+r" (ret), [ptr] "=m" (*addr)
                     : [val] "r" (val));
 
@@ -110,16 +106,12 @@ static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
 static inline int xen_safe_read_ulong(const unsigned long *addr,
                                      unsigned long *val)
 {
-       int ret = 0;
        unsigned long rval = ~0ul;
+       int ret = 0;
 
        asm volatile("1: mov %[ptr], %[rval]\n"
                     "2:\n"
-                    ".section .fixup, \"ax\"\n"
-                    "3: sub $1, %[ret]\n"
-                    "   jmp 2b\n"
-                    ".previous\n"
-                    _ASM_EXTABLE(1b, 3b)
+                    _ASM_EXTABLE_TYPE_REG(1b, 2b, EX_TYPE_EFAULT_REG, %[ret])
                     : [ret] "+r" (ret), [rval] "+r" (rval)
                     : [ptr] "m" (*addr));
        *val = rval;