From: Sai Prakash Ranjan <quic_saipraka@quicinc.com>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Catalin Marinas <catalin.marinas@arm.com>,
<quic_psodagud@quicinc.com>, "Marc Zyngier" <maz@kernel.org>,
gregkh <gregkh@linuxfoundation.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCHv4 2/2] arm64/io: Add a header for mmio access instrumentation
Date: Fri, 19 Nov 2021 09:36:39 +0530 [thread overview]
Message-ID: <b07e339c-530d-683c-c626-14b73b42e72a@quicinc.com> (raw)
In-Reply-To: <CAK8P3a2Bp4LP7C1-XLKvjyxV-e1vrHb-=3zpm75CRgPYNbY2jA@mail.gmail.com>
Hi Arnd,
On 11/18/2021 8:54 PM, Arnd Bergmann wrote:
> On Mon, Nov 15, 2021 at 12:33 PM Sai Prakash Ranjan
> <quic_saipraka@quicinc.com> wrote:
>> /*
>> * 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));
>> }
> Woundn't removing the #define here will break the logic in
> include/asm-generic/io.h,
> making it fall back to the pointer-dereference version for the actual access?
#defines for these are added in mmio-instrumented.h header which is
included in
arm64/asm/io.h, so it won't break the logic by falling back to
pointer-dereference.
>> +#if IS_ENABLED(CONFIG_TRACE_MMIO_ACCESS) && !(defined(__DISABLE_TRACE_MMIO__))
>> +DECLARE_TRACEPOINT(rwmmio_write);
>> +DECLARE_TRACEPOINT(rwmmio_read);
>> +
>> +void log_write_mmio(const char *width, volatile void __iomem *addr);
>> +void log_read_mmio(const char *width, const volatile void __iomem *addr);
>> +
>> +#define __raw_write(v, a, _l) ({ \
>> + volatile void __iomem *_a = (a); \
>> + if (tracepoint_enabled(rwmmio_write)) \
>> + log_write_mmio(__stringify(write##_l), _a); \
>> + arch_raw_write##_l((v), _a); \
>> + })
> This feels like it's getting too big to be inlined. Have you considered
> integrating this with the lib/logic_iomem.c infrastructure instead?
>
> That already provides a way to override MMIO areas, and it lets you do
> the logging from a single place rather than having it duplicated in every
> single caller. It also provides a way of filtering it based on the ioremap()
> call.
>
Thanks for the suggestion, will look at the logic_iomem.c and see if it
fits our
usecase.
Thanks,
Sai
next prev parent reply other threads:[~2021-11-19 4:06 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-15 11:33 [PATCHv4 0/2] tracing/rwmmio/arm64: Add support to trace register reads/writes Sai Prakash Ranjan
2021-11-15 11:33 ` [PATCHv4 1/2] tracing: Add register read/write tracing support Sai Prakash Ranjan
2021-11-19 13:43 ` Marc Zyngier
2021-11-19 14:07 ` Sai Prakash Ranjan
2021-11-19 14:17 ` Marc Zyngier
2021-11-19 15:19 ` Sai Prakash Ranjan
2021-11-15 11:33 ` [PATCHv4 2/2] arm64/io: Add a header for mmio access instrumentation Sai Prakash Ranjan
2021-11-16 22:40 ` Steven Rostedt
2021-11-17 3:53 ` Sai Prakash Ranjan
2021-11-18 14:58 ` kernel test robot
2021-11-18 15:24 ` Arnd Bergmann
2021-11-19 4:06 ` Sai Prakash Ranjan [this message]
2021-11-22 13:35 ` Sai Prakash Ranjan
2021-11-22 13:59 ` Arnd Bergmann
2021-11-22 14:19 ` Sai Prakash Ranjan
2021-11-22 14:30 ` Arnd Bergmann
2021-11-22 14:59 ` Sai Prakash Ranjan
2021-11-22 15:35 ` Arnd Bergmann
2021-11-22 15:43 ` Sai Prakash Ranjan
2021-11-29 13:49 ` Sai Prakash Ranjan
2021-11-19 13:48 ` Marc Zyngier
2021-11-19 14:09 ` Sai Prakash Ranjan
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