Commit 21003197 authored by Sai Prakash Ranjan's avatar Sai Prakash Ranjan Committed by Arnd Bergmann
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asm-generic/io: Add logging support for MMIO accessors 



Add logging support for MMIO high level accessors such as read{b,w,l,q}
and their relaxed versions to aid in debugging unexpected crashes/hangs
caused by the corresponding MMIO operation.

Signed-off-by: default avatarSai Prakash Ranjan <quic_saipraka@quicinc.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 451f2f1c

include/asm-generic/io.h

+87 −4
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <asm/page.h> /* I/O is all done through memory accesses */

#include <linux/string.h> /* for memset() and memcpy() */

#include <linux/types.h>

#include <linux/instruction_pointer.h>



#ifdef CONFIG_GENERIC_IOMAP

#include <asm-generic/iomap.h>
@@ -61,6 +62,44 @@ 
#define __io_par(v)     __io_ar(v)

#endif



/*

 * "__DISABLE_TRACE_MMIO__" flag can be used to disable MMIO tracing for

 * specific kernel drivers in case of excessive/unwanted logging.

 *

 * Usage: Add a #define flag at the beginning of the driver file.

 * Ex: #define __DISABLE_TRACE_MMIO__

 *     #include <...>

 *     ...

 */

#if IS_ENABLED(CONFIG_TRACE_MMIO_ACCESS) && !(defined(__DISABLE_TRACE_MMIO__))

#include <linux/tracepoint-defs.h>



DECLARE_TRACEPOINT(rwmmio_write);

DECLARE_TRACEPOINT(rwmmio_post_write);

DECLARE_TRACEPOINT(rwmmio_read);

DECLARE_TRACEPOINT(rwmmio_post_read);



void log_write_mmio(u64 val, u8 width, volatile void __iomem *addr,

		    unsigned long caller_addr);

void log_post_write_mmio(u64 val, u8 width, volatile void __iomem *addr,

			 unsigned long caller_addr);

void log_read_mmio(u8 width, const volatile void __iomem *addr,

		   unsigned long caller_addr);

void log_post_read_mmio(u64 val, u8 width, const volatile void __iomem *addr,

			unsigned long caller_addr);



#else



static inline void log_write_mmio(u64 val, u8 width, volatile void __iomem *addr,

				  unsigned long caller_addr) {}

static inline void log_post_write_mmio(u64 val, u8 width, volatile void __iomem *addr,

				       unsigned long caller_addr) {}

static inline void log_read_mmio(u8 width, const volatile void __iomem *addr,

				 unsigned long caller_addr) {}

static inline void log_post_read_mmio(u64 val, u8 width, const volatile void __iomem *addr,

				      unsigned long caller_addr) {}



#endif /* CONFIG_TRACE_MMIO_ACCESS */



/*

 * __raw_{read,write}{b,w,l,q}() access memory in native endianness.
@@ -149,9 +188,11 @@ static inline u8 readb(const volatile void __iomem *addr) 
{

	u8 val;



	log_read_mmio(8, addr, _THIS_IP_);

	__io_br();

	val = __raw_readb(addr);

	__io_ar(val);

	log_post_read_mmio(val, 8, addr, _THIS_IP_);

	return val;

}

#endif
@@ -162,9 +203,11 @@ static inline u16 readw(const volatile void __iomem *addr) 
{

	u16 val;



	log_read_mmio(16, addr, _THIS_IP_);

	__io_br();

	val = __le16_to_cpu((__le16 __force)__raw_readw(addr));

	__io_ar(val);

	log_post_read_mmio(val, 16, addr, _THIS_IP_);

	return val;

}

#endif
@@ -175,9 +218,11 @@ static inline u32 readl(const volatile void __iomem *addr) 
{

	u32 val;



	log_read_mmio(32, addr, _THIS_IP_);

	__io_br();

	val = __le32_to_cpu((__le32 __force)__raw_readl(addr));

	__io_ar(val);

	log_post_read_mmio(val, 32, addr, _THIS_IP_);

	return val;

}

#endif
@@ -189,9 +234,11 @@ static inline u64 readq(const volatile void __iomem *addr) 
{

	u64 val;



	log_read_mmio(64, addr, _THIS_IP_);

	__io_br();

	val = __le64_to_cpu(__raw_readq(addr));

	__io_ar(val);

	log_post_read_mmio(val, 64, addr, _THIS_IP_);

	return val;

}

#endif
@@ -201,9 +248,11 @@ static inline u64 readq(const volatile void __iomem *addr) 
#define writeb writeb

static inline void writeb(u8 value, volatile void __iomem *addr)

{

	log_write_mmio(value, 8, addr, _THIS_IP_);

	__io_bw();

	__raw_writeb(value, addr);

	__io_aw();

	log_post_write_mmio(value, 8, addr, _THIS_IP_);

}

#endif
@@ -211,9 +260,11 @@ static inline void writeb(u8 value, volatile void __iomem *addr) 
#define writew writew

static inline void writew(u16 value, volatile void __iomem *addr)

{

	log_write_mmio(value, 16, addr, _THIS_IP_);

	__io_bw();

	__raw_writew((u16 __force)cpu_to_le16(value), addr);

	__io_aw();

	log_post_write_mmio(value, 16, addr, _THIS_IP_);

}

#endif
@@ -221,9 +272,11 @@ static inline void writew(u16 value, volatile void __iomem *addr) 
#define writel writel

static inline void writel(u32 value, volatile void __iomem *addr)

{

	log_write_mmio(value, 32, addr, _THIS_IP_);

	__io_bw();

	__raw_writel((u32 __force)__cpu_to_le32(value), addr);

	__io_aw();

	log_post_write_mmio(value, 32, addr, _THIS_IP_);

}

#endif
@@ -232,9 +285,11 @@ static inline void writel(u32 value, volatile void __iomem *addr) 
#define writeq writeq

static inline void writeq(u64 value, volatile void __iomem *addr)

{

	log_write_mmio(value, 64, addr, _THIS_IP_);

	__io_bw();

	__raw_writeq(__cpu_to_le64(value), addr);

	__io_aw();

	log_post_write_mmio(value, 64, addr, _THIS_IP_);

}

#endif

#endif /* CONFIG_64BIT */
@@ -248,7 +303,12 @@ static inline void writeq(u64 value, volatile void __iomem *addr) 
#define readb_relaxed readb_relaxed

static inline u8 readb_relaxed(const volatile void __iomem *addr)

{

	return __raw_readb(addr);

	u8 val;



	log_read_mmio(8, addr, _THIS_IP_);

	val = __raw_readb(addr);

	log_post_read_mmio(val, 8, addr, _THIS_IP_);

	return val;

}

#endif
@@ -256,7 +316,12 @@ static inline u8 readb_relaxed(const volatile void __iomem *addr) 
#define readw_relaxed readw_relaxed

static inline u16 readw_relaxed(const volatile void __iomem *addr)

{

	return __le16_to_cpu(__raw_readw(addr));

	u16 val;



	log_read_mmio(16, addr, _THIS_IP_);

	val = __le16_to_cpu(__raw_readw(addr));

	log_post_read_mmio(val, 16, addr, _THIS_IP_);

	return val;

}

#endif
@@ -264,7 +329,12 @@ static inline u16 readw_relaxed(const volatile void __iomem *addr) 
#define readl_relaxed readl_relaxed

static inline u32 readl_relaxed(const volatile void __iomem *addr)

{

	return __le32_to_cpu(__raw_readl(addr));

	u32 val;



	log_read_mmio(32, addr, _THIS_IP_);

	val = __le32_to_cpu(__raw_readl(addr));

	log_post_read_mmio(val, 32, addr, _THIS_IP_);

	return val;

}

#endif
@@ -272,7 +342,12 @@ static inline u32 readl_relaxed(const volatile void __iomem *addr) 
#define readq_relaxed readq_relaxed

static inline u64 readq_relaxed(const volatile void __iomem *addr)

{

	return __le64_to_cpu(__raw_readq(addr));

	u64 val;



	log_read_mmio(64, addr, _THIS_IP_);

	val = __le64_to_cpu(__raw_readq(addr));

	log_post_read_mmio(val, 64, addr, _THIS_IP_);

	return val;

}

#endif
@@ -280,7 +355,9 @@ static inline u64 readq_relaxed(const volatile void __iomem *addr) 
#define writeb_relaxed writeb_relaxed

static inline void writeb_relaxed(u8 value, volatile void __iomem *addr)

{

	log_write_mmio(value, 8, addr, _THIS_IP_);

	__raw_writeb(value, addr);

	log_post_write_mmio(value, 8, addr, _THIS_IP_);

}

#endif
@@ -288,7 +365,9 @@ static inline void writeb_relaxed(u8 value, volatile void __iomem *addr) 
#define writew_relaxed writew_relaxed

static inline void writew_relaxed(u16 value, volatile void __iomem *addr)

{

	log_write_mmio(value, 16, addr, _THIS_IP_);

	__raw_writew(cpu_to_le16(value), addr);

	log_post_write_mmio(value, 16, addr, _THIS_IP_);

}

#endif
@@ -296,7 +375,9 @@ static inline void writew_relaxed(u16 value, volatile void __iomem *addr) 
#define writel_relaxed writel_relaxed

static inline void writel_relaxed(u32 value, volatile void __iomem *addr)

{

	log_write_mmio(value, 32, addr, _THIS_IP_);

	__raw_writel(__cpu_to_le32(value), addr);

	log_post_write_mmio(value, 32, addr, _THIS_IP_);

}

#endif
@@ -304,7 +385,9 @@ static inline void writel_relaxed(u32 value, volatile void __iomem *addr) 
#define writeq_relaxed writeq_relaxed

static inline void writeq_relaxed(u64 value, volatile void __iomem *addr)

{

	log_write_mmio(value, 64, addr, _THIS_IP_);

	__raw_writeq(__cpu_to_le64(value), addr);

	log_post_write_mmio(value, 64, addr, _THIS_IP_);

}

#endif