selftests/rseq: Fix ppc32 missing instruction selection "u" and "x" for load/store

Building the rseq basic test with
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.12)
Target: powerpc-linux-gnu

leads to these errors:

/tmp/ccieEWxU.s: Assembler messages:
/tmp/ccieEWxU.s:118: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:118: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:121: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:121: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:626: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:626: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:629: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:629: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:735: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:735: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:738: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:738: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:741: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:741: Error: junk at end of line: `,8'
Makefile:581: recipe for target 'basic_percpu_ops_test.o' failed

Based on discussion with Linux powerpc maintainers and review of
the use of the "m" operand in powerpc kernel code, add the missing
%Un%Xn (where n is operand number) to the lwz, stw, ld, and std
instructions when used with "m" operands.

Using "WORD" to mean either a 32-bit or 64-bit type depending on
the architecture is misleading. The term "WORD" really means a
32-bit type in both 32-bit and 64-bit powerpc assembler. The intent
here is to wrap load/store to intptr_t into common macros for both
32-bit and 64-bit.

Rename the macros with a RSEQ_ prefix, and use the terms "INT"
for always 32-bit type, and "LONG" for architecture bitness-sized
type.

Signed-off-by: Mathieu Desnoyers <[e-mail]>
Signed-off-by: Peter Zijlstra (Intel) <[e-mail]>
Link: https://lkml.kernel.org/r/[e-mail]

tools/testing/selftests/rseq/rseq-ppc.h

···
 
 #ifdef __PPC64__
 
-#define STORE_WORD	"std "
-#define LOAD_WORD	"ld "
-#define LOADX_WORD	"ldx "
-#define CMP_WORD	"cmpd "
+#define RSEQ_STORE_LONG(arg)	"std%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* To memory ("m" constraint) */
+#define RSEQ_STORE_INT(arg)	"stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* To memory ("m" constraint) */
+#define RSEQ_LOAD_LONG(arg)	"ld%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* From memory ("m" constraint) */
+#define RSEQ_LOAD_INT(arg)	"lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* From memory ("m" constraint) */
+#define RSEQ_LOADX_LONG		"ldx "							/* From base register ("b" constraint) */
+#define RSEQ_CMP_LONG		"cmpd "
+#define RSEQ_CMP_LONG_INT	"cmpdi "
 
 #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,				\
 			start_ip, post_commit_offset, abort_ip)			\
···
 
 #else /* #ifdef __PPC64__ */
 
-#define STORE_WORD	"stw "
-#define LOAD_WORD	"lwz "
-#define LOADX_WORD	"lwzx "
-#define CMP_WORD	"cmpw "
+#define RSEQ_STORE_LONG(arg)	"stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* To memory ("m" constraint) */
+#define RSEQ_STORE_INT(arg)	RSEQ_STORE_LONG(arg)					/* To memory ("m" constraint) */
+#define RSEQ_LOAD_LONG(arg)	"lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "	/* From memory ("m" constraint) */
+#define RSEQ_LOAD_INT(arg)	RSEQ_LOAD_LONG(arg)					/* From memory ("m" constraint) */
+#define RSEQ_LOADX_LONG		"lwzx "							/* From base register ("b" constraint) */
+#define RSEQ_CMP_LONG		"cmpw "
+#define RSEQ_CMP_LONG_INT	"cmpwi "
 
 #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,				\
 			start_ip, post_commit_offset, abort_ip)			\
···
 		RSEQ_INJECT_ASM(1)						\
 		"lis %%r17, (" __rseq_str(cs_label) ")@ha\n\t"			\
 		"addi %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t"		\
-		"stw %%r17, %[" __rseq_str(rseq_cs) "]\n\t"			\
+		RSEQ_STORE_INT(rseq_cs) "%%r17, %[" __rseq_str(rseq_cs) "]\n\t"	\
 		__rseq_str(label) ":\n\t"
 
 #endif /* #ifdef __PPC64__ */
···
 
 #define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label)			\
 		RSEQ_INJECT_ASM(2)						\
-		"lwz %%r17, %[" __rseq_str(current_cpu_id) "]\n\t"		\
+		RSEQ_LOAD_INT(current_cpu_id) "%%r17, %[" __rseq_str(current_cpu_id) "]\n\t" \
 		"cmpw cr7, %[" __rseq_str(cpu_id) "], %%r17\n\t"		\
 		"bne- cr7, " __rseq_str(label) "\n\t"
 
···
  * 	RSEQ_ASM_OP_* (else): doesn't have hard-code registers(unless cr7)
  */
 #define RSEQ_ASM_OP_CMPEQ(var, expect, label)					\
-		LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"			\
-		CMP_WORD "cr7, %%r17, %[" __rseq_str(expect) "]\n\t"		\
+		RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"		\
+		RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expect) "]\n\t"		\
 		"bne- cr7, " __rseq_str(label) "\n\t"
 
 #define RSEQ_ASM_OP_CMPNE(var, expectnot, label)				\
-		LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"			\
-		CMP_WORD "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t"		\
+		RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"		\
+		RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t"		\
 		"beq- cr7, " __rseq_str(label) "\n\t"
 
 #define RSEQ_ASM_OP_STORE(value, var)						\
-		STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"
+		RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"
 
 /* Load @var to r17 */
 #define RSEQ_ASM_OP_R_LOAD(var)							\
-		LOAD_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
+		RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"
 
 /* Store r17 to @var */
 #define RSEQ_ASM_OP_R_STORE(var)						\
-		STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t"
+		RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"
 
 /* Add @count to r17 */
 #define RSEQ_ASM_OP_R_ADD(count)						\
···
 
 /* Load (r17 + voffp) to r17 */
 #define RSEQ_ASM_OP_R_LOADX(voffp)						\
-		LOADX_WORD "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"
+		RSEQ_LOADX_LONG "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"
 
 /* TODO: implement a faster memcpy. */
 #define RSEQ_ASM_OP_R_MEMCPY() \
-		"cmpdi %%r19, 0\n\t" \
+		RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
 		"beq 333f\n\t" \
 		"addi %%r20, %%r20, -1\n\t" \
 		"addi %%r21, %%r21, -1\n\t" \
···
 		"lbzu %%r18, 1(%%r20)\n\t" \
 		"stbu %%r18, 1(%%r21)\n\t" \
 		"addi %%r19, %%r19, -1\n\t" \
-		"cmpdi %%r19, 0\n\t" \
+		RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
 		"bne 222b\n\t" \
 		"333:\n\t" \
 
 #define RSEQ_ASM_OP_R_FINAL_STORE(var, post_commit_label)			\
-		STORE_WORD "%%r17, %[" __rseq_str(var) "]\n\t"			\
+		RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"			\
 		__rseq_str(post_commit_label) ":\n\t"
 
 #define RSEQ_ASM_OP_FINAL_STORE(value, var, post_commit_label)			\
-		STORE_WORD "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
+		RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
 		__rseq_str(post_commit_label) ":\n\t"
 
 static inline __attribute__((always_inline))
···
 	rseq_bug("expected value comparison failed");
 #endif
 }
-
-#undef STORE_WORD
-#undef LOAD_WORD
-#undef LOADX_WORD
-#undef CMP_WORD
 
 #endif /* !RSEQ_SKIP_FASTPATH */