v4.19.13 snapshot.
diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h
new file mode 100644
index 0000000..8823684
--- /dev/null
+++ b/include/linux/mmiotrace.h
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_MMIOTRACE_H
+#define _LINUX_MMIOTRACE_H
+
+#include <linux/types.h>
+#include <linux/list.h>
+
+struct kmmio_probe;
+struct pt_regs;
+
+typedef void (*kmmio_pre_handler_t)(struct kmmio_probe *,
+ struct pt_regs *, unsigned long addr);
+typedef void (*kmmio_post_handler_t)(struct kmmio_probe *,
+ unsigned long condition, struct pt_regs *);
+
+struct kmmio_probe {
+ /* kmmio internal list: */
+ struct list_head list;
+ /* start location of the probe point: */
+ unsigned long addr;
+ /* length of the probe region: */
+ unsigned long len;
+ /* Called before addr is executed: */
+ kmmio_pre_handler_t pre_handler;
+ /* Called after addr is executed: */
+ kmmio_post_handler_t post_handler;
+ void *private;
+};
+
+extern unsigned int kmmio_count;
+
+extern int register_kmmio_probe(struct kmmio_probe *p);
+extern void unregister_kmmio_probe(struct kmmio_probe *p);
+extern int kmmio_init(void);
+extern void kmmio_cleanup(void);
+
+#ifdef CONFIG_MMIOTRACE
+/* kmmio is active by some kmmio_probes? */
+static inline int is_kmmio_active(void)
+{
+ return kmmio_count;
+}
+
+/* Called from page fault handler. */
+extern int kmmio_handler(struct pt_regs *regs, unsigned long addr);
+
+/* Called from ioremap.c */
+extern void mmiotrace_ioremap(resource_size_t offset, unsigned long size,
+ void __iomem *addr);
+extern void mmiotrace_iounmap(volatile void __iomem *addr);
+
+/* For anyone to insert markers. Remember trailing newline. */
+extern __printf(1, 2) int mmiotrace_printk(const char *fmt, ...);
+#else /* !CONFIG_MMIOTRACE: */
+static inline int is_kmmio_active(void)
+{
+ return 0;
+}
+
+static inline int kmmio_handler(struct pt_regs *regs, unsigned long addr)
+{
+ return 0;
+}
+
+static inline void mmiotrace_ioremap(resource_size_t offset,
+ unsigned long size, void __iomem *addr)
+{
+}
+
+static inline void mmiotrace_iounmap(volatile void __iomem *addr)
+{
+}
+
+static inline __printf(1, 2) int mmiotrace_printk(const char *fmt, ...)
+{
+ return 0;
+}
+#endif /* CONFIG_MMIOTRACE */
+
+enum mm_io_opcode {
+ MMIO_READ = 0x1, /* struct mmiotrace_rw */
+ MMIO_WRITE = 0x2, /* struct mmiotrace_rw */
+ MMIO_PROBE = 0x3, /* struct mmiotrace_map */
+ MMIO_UNPROBE = 0x4, /* struct mmiotrace_map */
+ MMIO_UNKNOWN_OP = 0x5, /* struct mmiotrace_rw */
+};
+
+struct mmiotrace_rw {
+ resource_size_t phys; /* PCI address of register */
+ unsigned long value;
+ unsigned long pc; /* optional program counter */
+ int map_id;
+ unsigned char opcode; /* one of MMIO_{READ,WRITE,UNKNOWN_OP} */
+ unsigned char width; /* size of register access in bytes */
+};
+
+struct mmiotrace_map {
+ resource_size_t phys; /* base address in PCI space */
+ unsigned long virt; /* base virtual address */
+ unsigned long len; /* mapping size */
+ int map_id;
+ unsigned char opcode; /* MMIO_PROBE or MMIO_UNPROBE */
+};
+
+/* in kernel/trace/trace_mmiotrace.c */
+extern void enable_mmiotrace(void);
+extern void disable_mmiotrace(void);
+extern void mmio_trace_rw(struct mmiotrace_rw *rw);
+extern void mmio_trace_mapping(struct mmiotrace_map *map);
+extern __printf(1, 0) int mmio_trace_printk(const char *fmt, va_list args);
+
+#endif /* _LINUX_MMIOTRACE_H */