[PATCH 5/6] arm64/io: Add header for instrumentation of io operations

[Sai Prakash Ranjan]

The new asm-generic/io-instrumented.h will keep arch code
clean and separate from instrumented version which traces
io register accesses. This instrumented header can later
be included in arm as well for tracing io register accesses.

Suggested-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
---
 arch/arm64/include/asm/io.h           | 25 ++++++---------
 include/asm-generic/io-instrumented.h | 45 +++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 16 deletions(-)
 create mode 100644 include/asm-generic/io-instrumented.h

diff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h
index 35b2e50f17fb..768a6a8c5778 100644
--- a/arch/arm64/include/asm/io.h
+++ b/arch/arm64/include/asm/io.h
@@ -36,32 +36,27 @@
 /*
  * Generic IO read/write.  These perform native-endian accesses.
  */
-#define __raw_writeb __raw_writeb
-static inline void __raw_writeb(u8 val, volatile void __iomem *addr)
+static inline void arch_raw_writeb(u8 val, volatile void __iomem *addr)
 {
 	asm volatile("strb %w0, [%1]" : : "rZ" (val), "r" (addr));
 }
 
-#define __raw_writew __raw_writew
-static inline void __raw_writew(u16 val, volatile void __iomem *addr)
+static inline void arch_raw_writew(u16 val, volatile void __iomem *addr)
 {
 	asm volatile("strh %w0, [%1]" : : "rZ" (val), "r" (addr));
 }
 
-#define __raw_writel __raw_writel
-static inline void __raw_writel(u32 val, volatile void __iomem *addr)
+static inline void arch_raw_writel(u32 val, volatile void __iomem *addr)
 {
 	asm volatile("str %w0, [%1]" : : "rZ" (val), "r" (addr));
 }
 
-#define __raw_writeq __raw_writeq
-static inline void __raw_writeq(u64 val, volatile void __iomem *addr)
+static inline void arch_raw_writeq(u64 val, volatile void __iomem *addr)
 {
 	asm volatile("str %x0, [%1]" : : "rZ" (val), "r" (addr));
 }
 
-#define __raw_readb __raw_readb
-static inline u8 __raw_readb(const volatile void __iomem *addr)
+static inline u8 arch_raw_readb(const volatile void __iomem *addr)
 {
 	u8 val;
 	asm volatile(ALTERNATIVE("ldrb %w0, [%1]",
@@ -71,8 +66,7 @@ static inline u8 __raw_readb(const volatile void __iomem *addr)
 	return val;
 }
 
-#define __raw_readw __raw_readw
-static inline u16 __raw_readw(const volatile void __iomem *addr)
+static inline u16 arch_raw_readw(const volatile void __iomem *addr)
 {
 	u16 val;
 
@@ -83,8 +77,7 @@ static inline u16 __raw_readw(const volatile void __iomem *addr)
 	return val;
 }
 
-#define __raw_readl __raw_readl
-static inline u32 __raw_readl(const volatile void __iomem *addr)
+static inline u32 arch_raw_readl(const volatile void __iomem *addr)
 {
 	u32 val;
 	asm volatile(ALTERNATIVE("ldr %w0, [%1]",
@@ -94,8 +87,7 @@ static inline u32 __raw_readl(const volatile void __iomem *addr)
 	return val;
 }
 
-#define __raw_readq __raw_readq
-static inline u64 __raw_readq(const volatile void __iomem *addr)
+static inline u64 arch_raw_readq(const volatile void __iomem *addr)
 {
 	u64 val;
 	asm volatile(ALTERNATIVE("ldr %0, [%1]",
@@ -193,6 +185,7 @@ extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
 #define iowrite32be(v,p)	({ __iowmb(); __raw_writel((__force __u32)cpu_to_be32(v), p); })
 #define iowrite64be(v,p)	({ __iowmb(); __raw_writeq((__force __u64)cpu_to_be64(v), p); })
 
+#include <asm-generic/io-instrumented.h>
 #include <asm-generic/io.h>
 
 /*
diff --git a/include/asm-generic/io-instrumented.h b/include/asm-generic/io-instrumented.h
new file mode 100644
index 000000000000..7b050e2487ed
--- /dev/null
+++ b/include/asm-generic/io-instrumented.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_IO_INSTRUMENTED_H
+#define _ASM_GENERIC_IO_INSTRUMENTED_H
+
+#if defined(CONFIG_TRACING_EVENTS_IO)
+#include <linux/tracepoint-defs.h>
+
+extern struct tracepoint __tracepoint_io_write;
+extern struct tracepoint __tracepoint_io_read;
+#define io_tracepoint_active(t) static_key_false(&(t).key)
+extern void do_trace_io_write(const char *type, void *addr);
+extern void do_trace_io_read(const char *type, void *addr);
+#else
+#define io_tracepoint_active(t) false
+static inline void do_trace_io_write(const char *type, void *addr) {}
+static inline void do_trace_io_read(const char *type, void *addr) {}
+#endif /* CONFIG_TRACING_EVENTS_IO */
+
+#define __raw_write(v, a, _l)	({						\
+	volatile void __iomem *_a = (a);					\
+	if (io_tracepoint_active(__tracepoint_io_write))			\
+		do_trace_io_write(__stringify(write##_l), (void __force *)(_a));\
+	arch_raw_write##_l((v), _a);						\
+	})
+
+#define __raw_writeb(v, a)	__raw_write((v), a, b)
+#define __raw_writew(v, a)	__raw_write((v), a, w)
+#define __raw_writel(v, a)	__raw_write((v), a, l)
+#define __raw_writeq(v, a)	__raw_write((v), a, q)
+
+#define __raw_read(a, _l, _t)    ({						\
+	_t __a;									\
+	const volatile void __iomem *_a = (a);					\
+	if (io_tracepoint_active(__tracepoint_io_read))				\
+		do_trace_io_read(__stringify(read##_l), (void __force *)(_a));	\
+	__a = arch_raw_read##_l(_a);						\
+	__a;									\
+	})
+
+#define __raw_readb(a)	__raw_read((a), b, u8)
+#define __raw_readw(a)	__raw_read((a), w, u16)
+#define __raw_readl(a)	__raw_read((a), l, u32)
+#define __raw_readq(a)	__raw_read((a), q, u64)
+
+#endif /* _ASM_GENERIC_IO_INSTRUMENTED_H */
-- 
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