s390/cpufeature: Convert MACHINE_HAS_SEQ_INSN to cpu_has_seq_insn()

Convert MACHINE_HAS_... to cpu_has_...() which uses test_facility() instead
of testing the machine_flags lowcore member if the feature is present.

test_facility() generates better code since it results in a static branch
without accessing memory. The branch is patched via alternatives by the
decompressor depending on the availability of the required facility.

Reviewed-by: Vasily Gorbik <[e-mail]>
Signed-off-by: Heiko Carstens <[e-mail]>
Signed-off-by: Vasily Gorbik <[e-mail]>

arch/s390/include/asm/cpufeature.h

···
 #ifndef __ASM_S390_CPUFEATURE_H
 #define __ASM_S390_CPUFEATURE_H
 
+#include <asm/facility.h>
+
 enum {
 	S390_CPU_FEATURE_MSA,
 	S390_CPU_FEATURE_VXRS,
···
 #define cpu_feature(feature)	(feature)
 
 int cpu_have_feature(unsigned int nr);
+
+#define cpu_has_seq_insn()	test_facility(85)
 
 #endif /* __ASM_S390_CPUFEATURE_H */

arch/s390/include/asm/setup.h

···
 #define MACHINE_FLAG_SCC	BIT(17)
 #define MACHINE_FLAG_PCI_MIO	BIT(18)
 #define MACHINE_FLAG_RDP	BIT(19)
-#define MACHINE_FLAG_SEQ_INSN	BIT(20)
 
 #define LPP_MAGIC		BIT(31)
 #define LPP_PID_MASK		_AC(0xffffffff, UL)
···
 #define MACHINE_HAS_SCC		(get_lowcore()->machine_flags & MACHINE_FLAG_SCC)
 #define MACHINE_HAS_PCI_MIO	(get_lowcore()->machine_flags & MACHINE_FLAG_PCI_MIO)
 #define MACHINE_HAS_RDP		(get_lowcore()->machine_flags & MACHINE_FLAG_RDP)
-#define MACHINE_HAS_SEQ_INSN	(get_lowcore()->machine_flags & MACHINE_FLAG_SEQ_INSN)
 
 /*
  * Console mode. Override with conmode=

arch/s390/kernel/early.c

···
 	}
 	if (test_facility(194))
 		get_lowcore()->machine_flags |= MACHINE_FLAG_RDP;
-	if (test_facility(85))
-		get_lowcore()->machine_flags |= MACHINE_FLAG_SEQ_INSN;
 }
 
 static inline void save_vector_registers(void)

arch/s390/kernel/ftrace.c

···
 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/kmsan-checks.h>
+#include <linux/cpufeature.h>
 #include <linux/kprobes.h>
 #include <linux/execmem.h>
 #include <trace/syscall.h>
···
 
 bool ftrace_need_init_nop(void)
 {
-	return !MACHINE_HAS_SEQ_INSN;
+	return !cpu_has_seq_insn();
 }
 
 int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
···
 int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
 		       unsigned long addr)
 {
-	if (MACHINE_HAS_SEQ_INSN)
+	if (cpu_has_seq_insn())
 		return ftrace_patch_branch_insn(rec->ip, old_addr, addr);
 	else
 		return ftrace_modify_trampoline_call(rec, old_addr, addr);
···
 int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec,
 		    unsigned long addr)
 {
-	/* Expect brcl 0xf,... for the !MACHINE_HAS_SEQ_INSN case */
-	if (MACHINE_HAS_SEQ_INSN)
+	/* Expect brcl 0xf,... for the !cpu_has_seq_insn() case */
+	if (cpu_has_seq_insn())
 		return ftrace_patch_branch_insn(rec->ip, addr, 0);
 	else
 		return ftrace_patch_branch_mask((void *)rec->ip, 0xc0f4, false);
···
 
 int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
 {
-	if (MACHINE_HAS_SEQ_INSN)
+	if (cpu_has_seq_insn())
 		return ftrace_patch_branch_insn(rec->ip, 0, addr);
 	else
 		return ftrace_make_trampoline_call(rec, addr);

arch/s390/kernel/kprobes.c

···
 #include <linux/ptrace.h>
 #include <linux/preempt.h>
 #include <linux/stop_machine.h>
+#include <linux/cpufeature.h>
 #include <linux/kdebug.h>
 #include <linux/uaccess.h>
 #include <linux/extable.h>
···
 {
 	struct swap_insn_args args = {.p = p, .arm_kprobe = 1};
 
-	if (MACHINE_HAS_SEQ_INSN) {
+	if (cpu_has_seq_insn()) {
 		swap_instruction(&args);
 		text_poke_sync();
 	} else {
···
 {
 	struct swap_insn_args args = {.p = p, .arm_kprobe = 0};
 
-	if (MACHINE_HAS_SEQ_INSN) {
+	if (cpu_has_seq_insn()) {
 		swap_instruction(&args);
 		text_poke_sync();
 	} else {