From: Heiko Carstens <hca@linux.ibm.com>
Date: Fri, 7 Feb 2025 14:49:09 +0000 (+0100)
Subject: s390/bear: Convert cpu_has_bear() to cpu feature function
X-Git-Tag: v6.15-rc1~113^2~39
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=841f35a08d4ae58322ed4e7fd68a50817d122602;p=thirdparty%2Fkernel%2Flinux.git

s390/bear: Convert cpu_has_bear() to cpu feature function

Get rid of the cpu_has_bear jump label and convert cpu_has_bear() to a cpu
feature function using test_facility() and with that use a static branch.

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

diff --git a/arch/s390/include/asm/cpufeature.h b/arch/s390/include/asm/cpufeature.h
index 781f45e88821c..e08169bd63a55 100644
--- a/arch/s390/include/asm/cpufeature.h
+++ b/arch/s390/include/asm/cpufeature.h
@@ -22,6 +22,7 @@ enum {
 
 int cpu_have_feature(unsigned int nr);
 
+#define cpu_has_bear()		test_facility(193)
 #define cpu_has_edat1()		test_facility(8)
 #define cpu_has_edat2()		test_facility(78)
 #define cpu_has_gs()		test_facility(133)
diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c
index d0a596f1c2f6f..17c074b11c517 100644
--- a/arch/s390/kernel/irq.c
+++ b/arch/s390/kernel/irq.c
@@ -9,6 +9,7 @@
  */
 
 #include <linux/kernel_stat.h>
+#include <linux/cpufeature.h>
 #include <linux/interrupt.h>
 #include <linux/seq_file.h>
 #include <linux/proc_fs.h>
@@ -150,7 +151,7 @@ void noinstr do_io_irq(struct pt_regs *regs)
 
 	if (user_mode(regs)) {
 		update_timer_sys();
-		if (static_branch_likely(&cpu_has_bear))
+		if (cpu_has_bear())
 			current->thread.last_break = regs->last_break;
 	}
 
@@ -186,7 +187,7 @@ void noinstr do_ext_irq(struct pt_regs *regs)
 
 	if (user_mode(regs)) {
 		update_timer_sys();
-		if (static_branch_likely(&cpu_has_bear))
+		if (cpu_has_bear())
 			current->thread.last_break = regs->last_break;
 	}
 
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index dc8ccc5e8edf4..b6686d63b7541 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -181,8 +181,6 @@ unsigned long __bootdata_preserved(MODULES_END);
 struct lowcore *lowcore_ptr[NR_CPUS];
 EXPORT_SYMBOL(lowcore_ptr);
 
-DEFINE_STATIC_KEY_FALSE(cpu_has_bear);
-
 /*
  * The Write Back bit position in the physaddr is given by the SLPC PCI.
  * Leaving the mask zero always uses write through which is safe
@@ -982,10 +980,6 @@ void __init setup_arch(char **cmdline_p)
 	numa_setup();
 	smp_detect_cpus();
 	topology_init_early();
-
-	if (test_facility(193))
-		static_branch_enable(&cpu_has_bear);
-
 	setup_protection_map();
 	/*
 	 * Create kernel page tables.
diff --git a/arch/s390/kernel/syscall.c b/arch/s390/kernel/syscall.c
index 5ec28028315b5..c8df656b08bcf 100644
--- a/arch/s390/kernel/syscall.c
+++ b/arch/s390/kernel/syscall.c
@@ -12,6 +12,7 @@
  *  platform.
  */
 
+#include <linux/cpufeature.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
 #include <linux/mm.h>
@@ -127,7 +128,7 @@ void noinstr __do_syscall(struct pt_regs *regs, int per_trap)
 	regs->psw = get_lowcore()->svc_old_psw;
 	regs->int_code = get_lowcore()->svc_int_code;
 	update_timer_sys();
-	if (static_branch_likely(&cpu_has_bear))
+	if (cpu_has_bear())
 		current->thread.last_break = regs->last_break;
 
 	local_irq_enable();
diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index 24fee11b030d8..a27053a405a74 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -15,6 +15,7 @@
  */
 #include "asm/irqflags.h"
 #include "asm/ptrace.h"
+#include <linux/cpufeature.h>
 #include <linux/kprobes.h>
 #include <linux/kdebug.h>
 #include <linux/randomize_kstack.h>
@@ -341,7 +342,7 @@ void noinstr __do_pgm_check(struct pt_regs *regs)
 
 	if (user_mode(regs)) {
 		update_timer_sys();
-		if (!static_branch_likely(&cpu_has_bear)) {
+		if (!cpu_has_bear()) {
 			if (regs->last_break < 4096)
 				regs->last_break = 1;
 		}
diff --git a/arch/s390/mm/dump_pagetables.c b/arch/s390/mm/dump_pagetables.c
index b60bc2b428715..d3e943752fa0a 100644
--- a/arch/s390/mm/dump_pagetables.c
+++ b/arch/s390/mm/dump_pagetables.c
@@ -84,7 +84,7 @@ static void note_prot_wx(struct pg_state *st, unsigned long addr)
 	 * in which case we have two lpswe instructions in lowcore that need
 	 * to be executable.
 	 */
-	if (addr == PAGE_SIZE && (nospec_uses_trampoline() || !static_key_enabled(&cpu_has_bear)))
+	if (addr == PAGE_SIZE && (nospec_uses_trampoline() || !cpu_has_bear()))
 		return;
 	WARN_ONCE(IS_ENABLED(CONFIG_DEBUG_WX),
 		  "s390/mm: Found insecure W+X mapping at address %pS\n",
@@ -178,7 +178,7 @@ bool ptdump_check_wx(void)
 		return false;
 	} else {
 		pr_info("Checked W+X mappings: passed, no %sW+X pages found\n",
-			(nospec_uses_trampoline() || !static_key_enabled(&cpu_has_bear)) ?
+			(nospec_uses_trampoline() || !cpu_has_bear()) ?
 			"unexpected " : "");
 
 		return true;
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index 5d2d39f05d8cd..448dd6ed1069b 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -660,7 +660,7 @@ void __init vmem_map_init(void)
 	 * prefix page is used to return to the previous context with
 	 * an LPSWE instruction and therefore must be executable.
 	 */
-	if (!static_key_enabled(&cpu_has_bear))
+	if (!cpu_has_bear())
 		set_memory_x(0, 1);
 	if (debug_pagealloc_enabled())
 		__set_memory_4k(__va(0), absolute_pointer(__va(0)) + ident_map_size);