Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/arch/x86/include/asm/spinlock.h b/arch/x86/include/asm/spinlock.h
new file mode 100644
index 000000000..5b6bc7016
--- /dev/null
+++ b/arch/x86/include/asm/spinlock.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_SPINLOCK_H
+#define _ASM_X86_SPINLOCK_H
+
+#include <linux/jump_label.h>
+#include <linux/atomic.h>
+#include <asm/page.h>
+#include <asm/processor.h>
+#include <linux/compiler.h>
+#include <asm/paravirt.h>
+#include <asm/bitops.h>
+
+/*
+ * Your basic SMP spinlocks, allowing only a single CPU anywhere
+ *
+ * Simple spin lock operations.  There are two variants, one clears IRQ's
+ * on the local processor, one does not.
+ *
+ * These are fair FIFO ticket locks, which support up to 2^16 CPUs.
+ *
+ * (the type definitions are in asm/spinlock_types.h)
+ */
+
+/* How long a lock should spin before we consider blocking */
+#define SPIN_THRESHOLD	(1 << 15)
+
+#include <asm/qspinlock.h>
+
+/*
+ * Read-write spinlocks, allowing multiple readers
+ * but only one writer.
+ *
+ * NOTE! it is quite common to have readers in interrupts
+ * but no interrupt writers. For those circumstances we
+ * can "mix" irq-safe locks - any writer needs to get a
+ * irq-safe write-lock, but readers can get non-irqsafe
+ * read-locks.
+ *
+ * On x86, we implement read-write locks using the generic qrwlock with
+ * x86 specific optimization.
+ */
+
+#include <asm/qrwlock.h>
+
+#endif /* _ASM_X86_SPINLOCK_H */