1 files changed, 112 insertions, 0 deletions
diff --git a/include/linux/mmiotrace.h b/include/linux/mmiotrace.h
new file mode 100644
index 000000000..882368498
--- /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 */