@@ -29,6 +29,7 @@
({ \
u64 reg; \
asm volatile(ALTERNATIVE("mrs %0, " __stringify(r##nvh),\
+ DEFINE_MRS_S \
"mrs_s %0, " __stringify(r##vh),\
ARM64_HAS_VIRT_HOST_EXTN) \
: "=r" (reg)); \
@@ -39,6 +40,7 @@
do { \
u64 __val = (u64)(v); \
asm volatile(ALTERNATIVE("msr " __stringify(r##nvh) ", %x0",\
+ DEFINE_MSR_S \
"msr_s " __stringify(r##vh) ", %x0",\
ARM64_HAS_VIRT_HOST_EXTN) \
: : "rZ" (__val)); \
@@ -463,21 +463,58 @@
#include <linux/types.h>
-asm(
-" .irp num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30\n"
-" .equ .L__reg_num_x\\num, \\num\n"
-" .endr\n"
+#define ___MRS_MSR_S_REGNUM \
+" .irp num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30\n" \
+" .equ .L__reg_num_x\\num, \\num\n" \
+" .endr\n" \
" .equ .L__reg_num_xzr, 31\n"
-"\n"
-" .macro mrs_s, rt, sreg\n"
- __emit_inst(0xd5200000|(\\sreg)|(.L__reg_num_\\rt))
+
+#define ___MRS_S \
+" .macro mrs_s, rt, sreg\n" \
+ __emit_inst(0xd5200000|(\\sreg)|(.L__reg_num_\\rt)) \
" .endm\n"
-"\n"
-" .macro msr_s, sreg, rt\n"
- __emit_inst(0xd5000000|(\\sreg)|(.L__reg_num_\\rt))
+
+#define ___MSR_S \
+" .macro msr_s, sreg, rt\n" \
+ __emit_inst(0xd5000000|(\\sreg)|(.L__reg_num_\\rt)) \
" .endm\n"
+
+/*
+ * llvm-as doesn't allow macros defined in an asm block to be used in other
+ * asm blocks, which means we cannot define them globally.
+ */
+#if !defined(CONFIG_CLANG_LTO)
+asm(
+ ___MRS_MSR_S_REGNUM
+ ___MRS_S
+ ___MSR_S
);
+#undef ___MRS_MSR_S_REGNUM
+#define ___MRS_MSR_S_REGNUM
+#undef ___MRS_S
+#define ___MRS_S
+#undef ___MSR_S
+#define ___MSR_S
+#endif
+
+#define DEFINE_MRS_S \
+ ___MRS_MSR_S_REGNUM \
+ ___MRS_S
+
+#define DEFINE_MSR_S \
+ ___MRS_MSR_S_REGNUM \
+ ___MSR_S
+
+
+#define __mrs_s(r, v) \
+ DEFINE_MRS_S \
+" mrs_s %0, " __stringify(r) : "=r" (v)
+
+#define __msr_s(r, v) \
+ DEFINE_MSR_S \
+" msr_s " __stringify(r) ", %0" : : "r" (v)
+
/*
* Unlike read_cpuid, calls to read_sysreg are never expected to be
* optimized away or replaced with synthetic values.
@@ -502,15 +539,15 @@ asm(
* For registers without architectural names, or simply unsupported by
* GAS.
*/
-#define read_sysreg_s(r) ({ \
- u64 __val; \
- asm volatile("mrs_s %0, " __stringify(r) : "=r" (__val)); \
- __val; \
+#define read_sysreg_s(r) ({ \
+ u64 __val; \
+ asm volatile(__mrs_s(r, __val)); \
+ __val; \
})
-#define write_sysreg_s(v, r) do { \
- u64 __val = (u64)(v); \
- asm volatile("msr_s " __stringify(r) ", %x0" : : "rZ" (__val)); \
+#define write_sysreg_s(v, r) do { \
+ u64 __val = (u64)(v); \
+ asm volatile(__msr_s(r, __val)); \
} while (0)
static inline void config_sctlr_el1(u32 clear, u32 set)
Clang's integrated assembler does not allow assembly macros defined in one inline asm block using the .macro directive to be used across separate asm blocks. LLVM developers consider this a feature and not a bug, recommending code refactoring: https://bugs.llvm.org/show_bug.cgi?id=19749 As binutils doesn't allow macros to be redefined, this change adds C preprocessor macros that define the assembly macros globally for binutils and locally for clang's integrated assembler. Suggested-by: Greg Hackmann <ghackmann@google.com> Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Sami Tolvanen <samitolvanen@google.com> --- arch/arm64/include/asm/kvm_hyp.h | 2 ++ arch/arm64/include/asm/sysreg.h | 71 ++++++++++++++++++++++++++++++---------- 2 files changed, 56 insertions(+), 17 deletions(-)