s390: raise minimum supported machine generation to z10

Machine generations up to z9 (released in May 2006) have been officially
out of service for several years now (z9 end of service - January 31, 2019).
No distributions build kernels supporting those old machine generations
anymore, except Debian, which seems to pick the oldest supported
generation. The team supporting Debian on s390 has been notified about
the change.

Raising minimum supported machine generation to z10 helps to reduce
maintenance cost and effectively remove code, which is not getting
enough testing coverage due to lack of older hardware and distributions
support. Besides that this unblocks some optimization opportunities and
allows to use wider instruction set in asm files for future features
implementation. Due to this change spectre mitigation and usercopy
implementations could be drastically simplified and many newer instructions
could be converted from ".insn" encoding to instruction names.

Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

12 files changed, 16 insertions, 90 deletions

diff --git a/arch/s390/kernel/asm-offsets.c b/arch/s390/kernel/asm-offsets.c
index c253d3faf443..7c74f0e17e5a 100644
--- a/arch/s390/kernel/asm-offsets.c
+++ b/arch/s390/kernel/asm-offsets.c
@@ -122,7 +122,6 @@ int main(void)
 	OFFSET(__LC_LPP, lowcore, lpp);
 	OFFSET(__LC_CURRENT_PID, lowcore, current_pid);
 	OFFSET(__LC_GMAP, lowcore, gmap);
-	OFFSET(__LC_BR_R1, lowcore, br_r1_trampoline);
 	OFFSET(__LC_LAST_BREAK, lowcore, last_break);
 	/* software defined ABI-relevant lowcore locations 0xe00 - 0xe20 */
 	OFFSET(__LC_DUMP_REIPL, lowcore, ipib);
diff --git a/arch/s390/kernel/cache.c b/arch/s390/kernel/cache.c
index 8a9c3bf69f48..7ee3651d00ab 100644
--- a/arch/s390/kernel/cache.c
+++ b/arch/s390/kernel/cache.c
@@ -70,8 +70,6 @@ void show_cacheinfo(struct seq_file *m)
 	struct cacheinfo *cache;
 	int idx;
 
-	if (!test_facility(34))
-		return;
 	this_cpu_ci = get_cpu_cacheinfo(cpumask_any(cpu_online_mask));
 	for (idx = 0; idx < this_cpu_ci->num_leaves; idx++) {
 		cache = this_cpu_ci->info_list + idx;
@@ -131,8 +129,6 @@ int init_cache_level(unsigned int cpu)
 	union cache_topology ct;
 	enum cache_type ctype;
 
-	if (!test_facility(34))
-		return -EOPNOTSUPP;
 	if (!this_cpu_ci)
 		return -EINVAL;
 	ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
@@ -156,8 +152,6 @@ int populate_cache_leaves(unsigned int cpu)
 	union cache_topology ct;
 	enum cache_type ctype;
 
-	if (!test_facility(34))
-		return -EOPNOTSUPP;
 	ct.raw = ecag(EXTRACT_TOPOLOGY, 0, 0);
 	for (idx = 0, level = 0; level < this_cpu_ci->num_levels &&
 	     idx < this_cpu_ci->num_leaves; idx++, level++) {
diff --git a/arch/s390/kernel/ftrace.c b/arch/s390/kernel/ftrace.c
index d8b96c5923c0..5e1f7bc00a25 100644
--- a/arch/s390/kernel/ftrace.c
+++ b/arch/s390/kernel/ftrace.c
@@ -60,15 +60,6 @@ asm(
 #ifdef CONFIG_EXPOLINE
 asm(
 	"	.align 16\n"
-	"ftrace_shared_hotpatch_trampoline_ex:\n"
-	"	lmg	%r0,%r1,2(%r1)\n"
-	"	ex	%r0," __stringify(__LC_BR_R1) "(%r0)\n"
-	"	j	.\n"
-	"ftrace_shared_hotpatch_trampoline_ex_end:\n"
-);
-
-asm(
-	"	.align 16\n"
 	"ftrace_shared_hotpatch_trampoline_exrl:\n"
 	"	lmg	%r0,%r1,2(%r1)\n"
 	"	.insn	ril,0xc60000000000,%r0,0f\n" /* exrl */
@@ -90,12 +81,8 @@ static const char *ftrace_shared_hotpatch_trampoline(const char **end)
 	tend = ftrace_shared_hotpatch_trampoline_br_end;
 #ifdef CONFIG_EXPOLINE
 	if (!nospec_disable) {
-		tstart = ftrace_shared_hotpatch_trampoline_ex;
-		tend = ftrace_shared_hotpatch_trampoline_ex_end;
-		if (test_facility(35)) { /* exrl */
-			tstart = ftrace_shared_hotpatch_trampoline_exrl;
-			tend = ftrace_shared_hotpatch_trampoline_exrl_end;
-		}
+		tstart = ftrace_shared_hotpatch_trampoline_exrl;
+		tend = ftrace_shared_hotpatch_trampoline_exrl_end;
 	}
 #endif /* CONFIG_EXPOLINE */
 	if (end)
diff --git a/arch/s390/kernel/ftrace.h b/arch/s390/kernel/ftrace.h
index 69e416f4c6b0..7f75a9616406 100644
--- a/arch/s390/kernel/ftrace.h
+++ b/arch/s390/kernel/ftrace.h
@@ -16,8 +16,6 @@ extern struct ftrace_hotpatch_trampoline __ftrace_hotpatch_trampolines_start[];
 extern struct ftrace_hotpatch_trampoline __ftrace_hotpatch_trampolines_end[];
 extern const char ftrace_shared_hotpatch_trampoline_br[];
 extern const char ftrace_shared_hotpatch_trampoline_br_end[];
-extern const char ftrace_shared_hotpatch_trampoline_ex[];
-extern const char ftrace_shared_hotpatch_trampoline_ex_end[];
 extern const char ftrace_shared_hotpatch_trampoline_exrl[];
 extern const char ftrace_shared_hotpatch_trampoline_exrl_end[];
 extern const char ftrace_plt_template[];
diff --git a/arch/s390/kernel/mcount.S b/arch/s390/kernel/mcount.S
index 6ace43d7e8d2..1326927a17b5 100644
--- a/arch/s390/kernel/mcount.S
+++ b/arch/s390/kernel/mcount.S
@@ -35,14 +35,8 @@ ENDPROC(ftrace_stub)
 	.if \allregs == 1
 	# save psw mask
 	# don't put any instructions clobbering CC before this point
-#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
 	epsw	%r1,%r14
 	risbg	%r14,%r1,0,31,32
-#else
-	epsw	%r14,%r1
-	sllg	%r14,%r14,32
-	lr	%r14,%r1
-#endif
 	.endif
 
 	lgr	%r1,%r15
@@ -58,12 +52,7 @@ ENDPROC(ftrace_stub)
 
 	.if \allregs == 1
 	stg	%r14,(STACK_PTREGS_PSW)(%r15)
-#ifdef CONFIG_HAVE_MARCH_Z10_FEATURES
 	mvghi	STACK_PTREGS_FLAGS(%r15),_PIF_FTRACE_FULL_REGS
-#else
-	lghi	%r14,_PIF_FTRACE_FULL_REGS
-	stg	%r14,STACK_PTREGS_FLAGS(%r15)
-#endif
 	.else
 	xc	STACK_PTREGS_FLAGS(8,%r15),STACK_PTREGS_FLAGS(%r15)
 	.endif
diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index b032e556eeb7..c0dd72db77b8 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -517,15 +517,9 @@ int module_finalize(const Elf_Ehdr *hdr,
 
 		ij = me->core_layout.base + me->arch.plt_offset +
 			me->arch.plt_size - PLT_ENTRY_SIZE;
-		if (test_facility(35)) {
-			ij[0] = 0xc6000000;	/* exrl	%r0,.+10	*/
-			ij[1] = 0x0005a7f4;	/* j	.		*/
-			ij[2] = 0x000007f1;	/* br	%r1		*/
-		} else {
-			ij[0] = 0x44000000 | (unsigned int)
-				offsetof(struct lowcore, br_r1_trampoline);
-			ij[1] = 0xa7f40000;	/* j	.		*/
-		}
+		ij[0] = 0xc6000000;	/* exrl	%r0,.+10	*/
+		ij[1] = 0x0005a7f4;	/* j	.		*/
+		ij[2] = 0x000007f1;	/* br	%r1		*/
 	}
 
 	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
diff --git a/arch/s390/kernel/nospec-branch.c b/arch/s390/kernel/nospec-branch.c
index c302e0a7d38f..717bbcc056e5 100644
--- a/arch/s390/kernel/nospec-branch.c
+++ b/arch/s390/kernel/nospec-branch.c
@@ -118,12 +118,6 @@ static void __init_or_module __nospec_revert(s32 *start, s32 *end)
 		if (thunk[0] == 0xc6 && thunk[1] == 0x00)
 			/* exrl %r0,<target-br> */
 			br = thunk + (*(int *)(thunk + 2)) * 2;
-		else if (thunk[0] == 0xc0 && (thunk[1] & 0x0f) == 0x00 &&
-			 thunk[6] == 0x44 && thunk[7] == 0x00 &&
-			 (thunk[8] & 0x0f) == 0x00 && thunk[9] == 0x00 &&
-			 (thunk[1] & 0xf0) == (thunk[8] & 0xf0))
-			/* larl %rx,<target br> + ex %r0,0(%rx) */
-			br = thunk + (*(int *)(thunk + 2)) * 2;
 		else
 			continue;
 		if (br[0] != 0x07 || (br[1] & 0xf0) != 0xf0)
diff --git a/arch/s390/kernel/perf_cpum_cf.c b/arch/s390/kernel/perf_cpum_cf.c
index ee8707abdb6a..483ab5e10164 100644
--- a/arch/s390/kernel/perf_cpum_cf.c
+++ b/arch/s390/kernel/perf_cpum_cf.c
@@ -1451,6 +1451,8 @@ static size_t cfdiag_maxsize(struct cpumf_ctr_info *info)
 /* Get the CPU speed, try sampling facility first and CPU attributes second. */
 static void cfdiag_get_cpu_speed(void)
 {
+	unsigned long mhz;
+
 	if (cpum_sf_avail()) {			/* Sampling facility first */
 		struct hws_qsi_info_block si;
 
@@ -1464,12 +1466,9 @@ static void cfdiag_get_cpu_speed(void)
 	/* Fallback: CPU speed extract static part. Used in case
 	 * CPU Measurement Sampling Facility is turned off.
 	 */
-	if (test_facility(34)) {
-		unsigned long mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
-
-		if (mhz != -1UL)
-			cfdiag_cpu_speed = mhz & 0xffffffff;
-	}
+	mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
+	if (mhz != -1UL)
+		cfdiag_cpu_speed = mhz & 0xffffffff;
 }
 
 static int cfset_init(void)
diff --git a/arch/s390/kernel/processor.c b/arch/s390/kernel/processor.c
index d9d4a806979e..7a74ea5f7531 100644
--- a/arch/s390/kernel/processor.c
+++ b/arch/s390/kernel/processor.c
@@ -172,8 +172,7 @@ static void show_cpu_summary(struct seq_file *m, void *v)
 static int __init setup_hwcaps(void)
 {
 	/* instructions named N3, "backported" to esa-mode */
-	if (test_facility(0))
-		elf_hwcap |= HWCAP_ESAN3;
+	elf_hwcap |= HWCAP_ESAN3;
 
 	/* z/Architecture mode active */
 	elf_hwcap |= HWCAP_ZARCH;
@@ -191,8 +190,7 @@ static int __init setup_hwcaps(void)
 		elf_hwcap |= HWCAP_LDISP;
 
 	/* extended-immediate */
-	if (test_facility(21))
-		elf_hwcap |= HWCAP_EIMM;
+	elf_hwcap |= HWCAP_EIMM;
 
 	/* extended-translation facility 3 enhancement */
 	if (test_facility(22) && test_facility(30))
@@ -262,21 +260,7 @@ static int __init setup_elf_platform(void)
 	get_cpu_id(&cpu_id);
 	add_device_randomness(&cpu_id, sizeof(cpu_id));
 	switch (cpu_id.machine) {
-	case 0x2064:
-	case 0x2066:
-	default:	/* Use "z900" as default for 64 bit kernels. */
-		strcpy(elf_platform, "z900");
-		break;
-	case 0x2084:
-	case 0x2086:
-		strcpy(elf_platform, "z990");
-		break;
-	case 0x2094:
-	case 0x2096:
-		strcpy(elf_platform, "z9-109");
-		break;
-	case 0x2097:
-	case 0x2098:
+	default:	/* Use "z10" as default. */
 		strcpy(elf_platform, "z10");
 		break;
 	case 0x2817:
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index 05327be3a982..84e23fcc1106 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -490,7 +490,6 @@ static void __init setup_lowcore_dat_off(void)
 	lc->spinlock_lockval = arch_spin_lockval(0);
 	lc->spinlock_index = 0;
 	arch_spin_lock_setup(0);
-	lc->br_r1_trampoline = 0x07f1;	/* br %r1 */
 	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
 	lc->preempt_count = PREEMPT_DISABLED;
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index 368b58e4c2e7..127da1850b06 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -207,7 +207,6 @@ static int pcpu_alloc_lowcore(struct pcpu *pcpu, int cpu)
 	lc->cpu_nr = cpu;
 	lc->spinlock_lockval = arch_spin_lockval(cpu);
 	lc->spinlock_index = 0;
-	lc->br_r1_trampoline = 0x07f1;	/* br %r1 */
 	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
 	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
 	lc->preempt_count = PREEMPT_DISABLED;
diff --git a/arch/s390/kernel/uprobes.c b/arch/s390/kernel/uprobes.c
index bd3ef121c379..b88345ef8bd9 100644
--- a/arch/s390/kernel/uprobes.c
+++ b/arch/s390/kernel/uprobes.c
@@ -177,9 +177,7 @@ static void adjust_psw_addr(psw_t *psw, unsigned long len)
 	__typeof__(*(ptr)) input;			\
 	int __rc = 0;					\
 							\
-	if (!test_facility(34))				\
-		__rc = EMU_ILLEGAL_OP;			\
-	else if ((u64 __force)ptr & mask)		\
+	if ((u64 __force)ptr & mask)			\
 		__rc = EMU_SPECIFICATION;		\
 	else if (get_user(input, ptr))			\
 		__rc = EMU_ADDRESSING;			\
@@ -194,9 +192,7 @@ static void adjust_psw_addr(psw_t *psw, unsigned long len)
 	__typeof__(ptr) __ptr = (ptr);			\
 	int __rc = 0;					\
 							\
-	if (!test_facility(34))				\
-		__rc = EMU_ILLEGAL_OP;			\
-	else if ((u64 __force)__ptr & mask)		\
+	if ((u64 __force)__ptr & mask)			\
 		__rc = EMU_SPECIFICATION;		\
 	else if (put_user(*(input), __ptr))		\
 		__rc = EMU_ADDRESSING;			\
@@ -213,9 +209,7 @@ static void adjust_psw_addr(psw_t *psw, unsigned long len)
 	__typeof__(*(ptr)) input;			\
 	int __rc = 0;					\
 							\
-	if (!test_facility(34))				\
-		__rc = EMU_ILLEGAL_OP;			\
-	else if ((u64 __force)ptr & mask)		\
+	if ((u64 __force)ptr & mask)			\
 		__rc = EMU_SPECIFICATION;		\
 	else if (get_user(input, ptr))			\
 		__rc = EMU_ADDRESSING;			\
@@ -327,10 +321,6 @@ static void handle_insn_ril(struct arch_uprobe *auprobe, struct pt_regs *regs)
 		break;
 	case 0xc6:
 		switch (insn->opc1) {
-		case 0x02: /* pfdrl */
-			if (!test_facility(34))
-				rc = EMU_ILLEGAL_OP;
-			break;
 		case 0x04: /* cghrl */
 			rc = emu_cmp_ril(regs, (s16 __user *)uptr, &rx->s64);
 			break;