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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/s390/include/asm/preempt.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/s390/include/asm/preempt.h')
-rw-r--r--arch/s390/include/asm/preempt.h139
1 files changed, 139 insertions, 0 deletions
diff --git a/arch/s390/include/asm/preempt.h b/arch/s390/include/asm/preempt.h
new file mode 100644
index 000000000..bf15da0fe
--- /dev/null
+++ b/arch/s390/include/asm/preempt.h
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_PREEMPT_H
+#define __ASM_PREEMPT_H
+
+#include <asm/current.h>
+#include <linux/thread_info.h>
+#include <asm/atomic_ops.h>
+
+#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
+
+/* We use the MSB mostly because its available */
+#define PREEMPT_NEED_RESCHED 0x80000000
+#define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED)
+
+static inline int preempt_count(void)
+{
+ return READ_ONCE(S390_lowcore.preempt_count) & ~PREEMPT_NEED_RESCHED;
+}
+
+static inline void preempt_count_set(int pc)
+{
+ int old, new;
+
+ do {
+ old = READ_ONCE(S390_lowcore.preempt_count);
+ new = (old & PREEMPT_NEED_RESCHED) |
+ (pc & ~PREEMPT_NEED_RESCHED);
+ } while (__atomic_cmpxchg(&S390_lowcore.preempt_count,
+ old, new) != old);
+}
+
+static inline void set_preempt_need_resched(void)
+{
+ __atomic_and(~PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count);
+}
+
+static inline void clear_preempt_need_resched(void)
+{
+ __atomic_or(PREEMPT_NEED_RESCHED, &S390_lowcore.preempt_count);
+}
+
+static inline bool test_preempt_need_resched(void)
+{
+ return !(READ_ONCE(S390_lowcore.preempt_count) & PREEMPT_NEED_RESCHED);
+}
+
+static inline void __preempt_count_add(int val)
+{
+ /*
+ * With some obscure config options and CONFIG_PROFILE_ALL_BRANCHES
+ * enabled, gcc 12 fails to handle __builtin_constant_p().
+ */
+ if (!IS_ENABLED(CONFIG_PROFILE_ALL_BRANCHES)) {
+ if (__builtin_constant_p(val) && (val >= -128) && (val <= 127)) {
+ __atomic_add_const(val, &S390_lowcore.preempt_count);
+ return;
+ }
+ }
+ __atomic_add(val, &S390_lowcore.preempt_count);
+}
+
+static inline void __preempt_count_sub(int val)
+{
+ __preempt_count_add(-val);
+}
+
+static inline bool __preempt_count_dec_and_test(void)
+{
+ return __atomic_add(-1, &S390_lowcore.preempt_count) == 1;
+}
+
+static inline bool should_resched(int preempt_offset)
+{
+ return unlikely(READ_ONCE(S390_lowcore.preempt_count) ==
+ preempt_offset);
+}
+
+#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
+
+#define PREEMPT_ENABLED (0)
+
+static inline int preempt_count(void)
+{
+ return READ_ONCE(S390_lowcore.preempt_count);
+}
+
+static inline void preempt_count_set(int pc)
+{
+ S390_lowcore.preempt_count = pc;
+}
+
+static inline void set_preempt_need_resched(void)
+{
+}
+
+static inline void clear_preempt_need_resched(void)
+{
+}
+
+static inline bool test_preempt_need_resched(void)
+{
+ return false;
+}
+
+static inline void __preempt_count_add(int val)
+{
+ S390_lowcore.preempt_count += val;
+}
+
+static inline void __preempt_count_sub(int val)
+{
+ S390_lowcore.preempt_count -= val;
+}
+
+static inline bool __preempt_count_dec_and_test(void)
+{
+ return !--S390_lowcore.preempt_count && tif_need_resched();
+}
+
+static inline bool should_resched(int preempt_offset)
+{
+ return unlikely(preempt_count() == preempt_offset &&
+ tif_need_resched());
+}
+
+#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
+
+#define init_task_preempt_count(p) do { } while (0)
+/* Deferred to CPU bringup time */
+#define init_idle_preempt_count(p, cpu) do { } while (0)
+
+#ifdef CONFIG_PREEMPTION
+extern void preempt_schedule(void);
+#define __preempt_schedule() preempt_schedule()
+extern void preempt_schedule_notrace(void);
+#define __preempt_schedule_notrace() preempt_schedule_notrace()
+#endif /* CONFIG_PREEMPTION */
+
+#endif /* __ASM_PREEMPT_H */