Re: [PATCH v2] tracing: Add register read and write tracing support
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2020-11-06 06:49:36
Also in:
linux-arm-msm, lkml
On Thu, Nov 05, 2020 at 06:56:26PM -0800, Prasad Sodagudi wrote:
Add register read/write operations tracing support. ftrace events helps to trace register read and write location details of memory mapped IO registers.
This sentance does not parse for me, can you please rework it?
These trace logs helps to debug un clocked access of peripherals.
"un clocked"? What does that mean? And you do have 72 columns to fill, please use it :)
Signed-off-by: Prasad Sodagudi <redacted> --- arch/arm64/include/asm/io.h | 9 ++++++++ arch/arm64/kernel/image-vars.h | 8 +++++++
You are only adding it for arm64, why not add the generic support first, and then add it for all "major" arches afterwards?
quoted hunk ↗ jump to hunk
include/linux/iorw.h | 38 +++++++++++++++++++++++++++++++ include/trace/events/rwio.h | 51 ++++++++++++++++++++++++++++++++++++++++++ kernel/trace/Kconfig | 11 +++++++++ kernel/trace/Makefile | 1 + kernel/trace/trace_readwrite.c | 31 +++++++++++++++++++++++++ 7 files changed, 149 insertions(+) create mode 100644 include/linux/iorw.h create mode 100644 include/trace/events/rwio.h create mode 100644 kernel/trace/trace_readwrite.cdiff --git a/arch/arm64/include/asm/io.h b/arch/arm64/include/asm/io.h index fd172c4..bcfc65c 100644 --- a/arch/arm64/include/asm/io.h +++ b/arch/arm64/include/asm/io.h@@ -9,6 +9,7 @@ #define __ASM_IO_H #include <linux/types.h> +#include <linux/iorw.h> #include <linux/pgtable.h> #include <asm/byteorder.h>@@ -24,24 +25,28 @@ #define __raw_writeb __raw_writeb static inline void __raw_writeb(u8 val, volatile void __iomem *addr) { + log_write_io(addr); asm volatile("strb %w0, [%1]" : : "rZ" (val), "r" (addr));
Why are you not logging the value here, and everywhere else? You need to document why that is somewhere, as it's the most obvious question you will get. thanks, greg k-h _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel