[Xen-devel] [PATCH 06/12] xen/arm64: sysreg: Implement the 32-bit helpers using the 64-bit helpers

[Julien Grall <julien.grall@xxxxxxx>]

Clang is pickier than GCC for the register size in asm statement. It
expects the register size to match the value size.

The instructions msr/mrs are expecting a 64-bit register. This means the
implementation of the 32-bit helpers is not correct. The easiest
solution is to implement the 32-bit helpers using the 64-bit helpers.

Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
---
 xen/include/asm-arm/arm64/sysregs.h | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/xen/include/asm-arm/arm64/sysregs.h 
b/xen/include/asm-arm/arm64/sysregs.h
index 08585a969e..c60029d38f 100644
--- a/xen/include/asm-arm/arm64/sysregs.h
+++ b/xen/include/asm-arm/arm64/sysregs.h
@@ -59,14 +59,9 @@
 
 /* Access to system registers */
 
-#define READ_SYSREG32(name) ({                          \
-    uint32_t _r;                                        \
-    asm volatile("mrs  %0, "__stringify(name) : "=r" (_r));         \
-    _r; })
-#define WRITE_SYSREG32(v, name) do {                    \
-    uint32_t _r = v;                                    \
-    asm volatile("msr "__stringify(name)", %0" : : "r" (_r));       \
-} while (0)
+#define READ_SYSREG32(name) ((uint32_t)READ_SYSREG64(name))
+
+#define WRITE_SYSREG32(v, name) WRITE_SYSREG64((uint64_t)v, name)
 
 #define WRITE_SYSREG64(v, name) do {                    \
     uint64_t _r = v;                                    \
-- 
2.11.0


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