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-rw-r--r--arch/s390/boot/startup.c17
-rw-r--r--arch/s390/include/asm/cpufeature.h1
-rw-r--r--arch/s390/include/asm/diag288.h41
-rw-r--r--arch/s390/include/asm/machine.h1
-rw-r--r--arch/s390/kernel/cpufeature.c5
-rw-r--r--drivers/watchdog/diag288_wdt.c53
6 files changed, 68 insertions, 50 deletions
diff --git a/arch/s390/boot/startup.c b/arch/s390/boot/startup.c
index 06316fb8e0fa..da8337e63a3e 100644
--- a/arch/s390/boot/startup.c
+++ b/arch/s390/boot/startup.c
@@ -6,6 +6,7 @@
#include <asm/boot_data.h>
#include <asm/extmem.h>
#include <asm/sections.h>
+#include <asm/diag288.h>
#include <asm/maccess.h>
#include <asm/machine.h>
#include <asm/sysinfo.h>
@@ -71,6 +72,20 @@ static void detect_machine_type(void)
set_machine_feature(MFEATURE_VM);
}
+static void detect_diag288(void)
+{
+ /* "BEGIN" in EBCDIC character set */
+ static const char cmd[] = "\xc2\xc5\xc7\xc9\xd5";
+ unsigned long action, len;
+
+ action = machine_is_vm() ? (unsigned long)cmd : LPARWDT_RESTART;
+ len = machine_is_vm() ? sizeof(cmd) : 0;
+ if (__diag288(WDT_FUNC_INIT, MIN_INTERVAL, action, len))
+ return;
+ __diag288(WDT_FUNC_CANCEL, 0, 0, 0);
+ set_machine_feature(MFEATURE_DIAG288);
+}
+
static void detect_diag9c(void)
{
unsigned int cpu;
@@ -519,6 +534,8 @@ void startup_kernel(void)
detect_facilities();
detect_diag9c();
detect_machine_type();
+ /* detect_diag288() needs machine type */
+ detect_diag288();
cmma_init();
sanitize_prot_virt_host();
max_physmem_end = detect_max_physmem_end();
diff --git a/arch/s390/include/asm/cpufeature.h b/arch/s390/include/asm/cpufeature.h
index e08169bd63a5..6c6a99660e78 100644
--- a/arch/s390/include/asm/cpufeature.h
+++ b/arch/s390/include/asm/cpufeature.h
@@ -15,6 +15,7 @@ enum {
S390_CPU_FEATURE_MSA,
S390_CPU_FEATURE_VXRS,
S390_CPU_FEATURE_UV,
+ S390_CPU_FEATURE_D288,
MAX_CPU_FEATURES
};
diff --git a/arch/s390/include/asm/diag288.h b/arch/s390/include/asm/diag288.h
new file mode 100644
index 000000000000..5e1b43cea9d6
--- /dev/null
+++ b/arch/s390/include/asm/diag288.h
@@ -0,0 +1,41 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ASM_S390_DIAG288_H
+#define _ASM_S390_DIAG288_H
+
+#include <asm/asm-extable.h>
+#include <asm/types.h>
+
+#define MIN_INTERVAL 15 /* Minimal time supported by diag288 */
+#define MAX_INTERVAL 3600 /* One hour should be enough - pure estimation */
+
+#define WDT_DEFAULT_TIMEOUT 30
+
+/* Function codes - init, change, cancel */
+#define WDT_FUNC_INIT 0
+#define WDT_FUNC_CHANGE 1
+#define WDT_FUNC_CANCEL 2
+#define WDT_FUNC_CONCEAL 0x80000000
+
+/* Action codes for LPAR watchdog */
+#define LPARWDT_RESTART 0
+
+static inline int __diag288(unsigned int func, unsigned int timeout,
+ unsigned long action, unsigned int len)
+{
+ union register_pair r1 = { .even = func, .odd = timeout, };
+ union register_pair r3 = { .even = action, .odd = len, };
+ int rc = -EINVAL;
+
+ asm volatile(
+ " diag %[r1],%[r3],0x288\n"
+ "0: lhi %[rc],0\n"
+ "1:"
+ EX_TABLE(0b, 1b)
+ : [rc] "+d" (rc)
+ : [r1] "d" (r1.pair), [r3] "d" (r3.pair)
+ : "cc", "memory");
+ return rc;
+}
+
+#endif /* _ASM_S390_DIAG288_H */
diff --git a/arch/s390/include/asm/machine.h b/arch/s390/include/asm/machine.h
index 54478caa5237..8abe5afdbfc4 100644
--- a/arch/s390/include/asm/machine.h
+++ b/arch/s390/include/asm/machine.h
@@ -18,6 +18,7 @@
#define MFEATURE_VM 7
#define MFEATURE_KVM 8
#define MFEATURE_LPAR 9
+#define MFEATURE_DIAG288 10
#ifndef __ASSEMBLY__
diff --git a/arch/s390/kernel/cpufeature.c b/arch/s390/kernel/cpufeature.c
index 1b2ae42a0c15..76210f001028 100644
--- a/arch/s390/kernel/cpufeature.c
+++ b/arch/s390/kernel/cpufeature.c
@@ -5,11 +5,13 @@
#include <linux/cpufeature.h>
#include <linux/bug.h>
+#include <asm/machine.h>
#include <asm/elf.h>
enum {
TYPE_HWCAP,
TYPE_FACILITY,
+ TYPE_MACHINE,
};
struct s390_cpu_feature {
@@ -21,6 +23,7 @@ static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = {
[S390_CPU_FEATURE_MSA] = {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA},
[S390_CPU_FEATURE_VXRS] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS},
[S390_CPU_FEATURE_UV] = {.type = TYPE_FACILITY, .num = 158},
+ [S390_CPU_FEATURE_D288] = {.type = TYPE_MACHINE, .num = MFEATURE_DIAG288},
};
/*
@@ -38,6 +41,8 @@ int cpu_have_feature(unsigned int num)
return !!(elf_hwcap & BIT(feature->num));
case TYPE_FACILITY:
return test_facility(feature->num);
+ case TYPE_MACHINE:
+ return test_machine_feature(feature->num);
default:
WARN_ON_ONCE(1);
return 0;
diff --git a/drivers/watchdog/diag288_wdt.c b/drivers/watchdog/diag288_wdt.c
index 76dffc89c641..887d5a6c155b 100644
--- a/drivers/watchdog/diag288_wdt.c
+++ b/drivers/watchdog/diag288_wdt.c
@@ -29,26 +29,13 @@
#include <linux/watchdog.h>
#include <asm/machine.h>
#include <asm/ebcdic.h>
+#include <asm/diag288.h>
#include <asm/diag.h>
#include <linux/io.h>
#define MAX_CMDLEN 240
#define DEFAULT_CMD "SYSTEM RESTART"
-#define MIN_INTERVAL 15 /* Minimal time supported by diag88 */
-#define MAX_INTERVAL 3600 /* One hour should be enough - pure estimation */
-
-#define WDT_DEFAULT_TIMEOUT 30
-
-/* Function codes - init, change, cancel */
-#define WDT_FUNC_INIT 0
-#define WDT_FUNC_CHANGE 1
-#define WDT_FUNC_CANCEL 2
-#define WDT_FUNC_CONCEAL 0x80000000
-
-/* Action codes for LPAR watchdog */
-#define LPARWDT_RESTART 0
-
static char wdt_cmd[MAX_CMDLEN] = DEFAULT_CMD;
static bool conceal_on;
static bool nowayout_info = WATCHDOG_NOWAYOUT;
@@ -75,22 +62,8 @@ static char *cmd_buf;
static int diag288(unsigned int func, unsigned int timeout,
unsigned long action, unsigned int len)
{
- union register_pair r1 = { .even = func, .odd = timeout, };
- union register_pair r3 = { .even = action, .odd = len, };
- int err;
-
diag_stat_inc(DIAG_STAT_X288);
-
- err = -EINVAL;
- asm volatile(
- " diag %[r1],%[r3],0x288\n"
- "0: la %[err],0\n"
- "1:\n"
- EX_TABLE(0b, 1b)
- : [err] "+d" (err)
- : [r1] "d" (r1.pair), [r3] "d" (r3.pair)
- : "cc", "memory");
- return err;
+ return __diag288(func, timeout, action, len);
}
static int diag288_str(unsigned int func, unsigned int timeout, char *cmd)
@@ -189,8 +162,6 @@ static struct watchdog_device wdt_dev = {
static int __init diag288_init(void)
{
- int ret;
-
watchdog_set_nowayout(&wdt_dev, nowayout_info);
if (machine_is_vm()) {
@@ -199,24 +170,6 @@ static int __init diag288_init(void)
pr_err("The watchdog cannot be initialized\n");
return -ENOMEM;
}
-
- ret = diag288_str(WDT_FUNC_INIT, MIN_INTERVAL, "BEGIN");
- if (ret != 0) {
- pr_err("The watchdog cannot be initialized\n");
- kfree(cmd_buf);
- return -EINVAL;
- }
- } else {
- if (diag288(WDT_FUNC_INIT, WDT_DEFAULT_TIMEOUT,
- LPARWDT_RESTART, 0)) {
- pr_err("The watchdog cannot be initialized\n");
- return -EINVAL;
- }
- }
-
- if (diag288(WDT_FUNC_CANCEL, 0, 0, 0)) {
- pr_err("The watchdog cannot be deactivated\n");
- return -EINVAL;
}
return watchdog_register_device(&wdt_dev);
@@ -228,5 +181,5 @@ static void __exit diag288_exit(void)
kfree(cmd_buf);
}
-module_init(diag288_init);
+module_cpu_feature_match(S390_CPU_FEATURE_D288, diag288_init);
module_exit(diag288_exit);
generated by cgit v1.2.3 (git 2.39.0) at 2025-08-16 20:51:07 +0300