Message ID | f6d1b9e9d70968b506bdfd1b77129cb751b9df9d.1652891705.git.quic_saipraka@quicinc.com |
---|---|
State | New |
Headers | show |
Series | lib/rwmmio/arm64: Add support to trace register reads/writes | expand |
Hi Steve, On 5/18/2022 10:14 PM, Sai Prakash Ranjan wrote: > From: Prasad Sodagudi <psodagud@codeaurora.org> > > Generic MMIO read/write i.e., __raw_{read,write}{b,l,w,q} accessors > are typically used to read/write from/to memory mapped registers > and can cause hangs or some undefined behaviour in following few > cases, > > * If the access to the register space is unclocked, for example: if > there is an access to multimedia(MM) block registers without MM > clocks. > > * If the register space is protected and not set to be accessible from > non-secure world, for example: only EL3 (EL: Exception level) access > is allowed and any EL2/EL1 access is forbidden. > > * If xPU(memory/register protection units) is controlling access to > certain memory/register space for specific clients. > > and more... > > Such cases usually results in instant reboot/SErrors/NOC or interconnect > hangs and tracing these register accesses can be very helpful to debug > such issues during initial development stages and also in later stages. > > So use ftrace trace events to log such MMIO register accesses which > provides rich feature set such as early enablement of trace events, > filtering capability, dumping ftrace logs on console and many more. > > Sample output: > > rwmmio_write: __qcom_geni_serial_console_write+0x160/0x1e0 width=32 val=0xa0d5d addr=0xfffffbfffdbff700 > rwmmio_post_write: __qcom_geni_serial_console_write+0x160/0x1e0 width=32 val=0xa0d5d addr=0xfffffbfffdbff700 > rwmmio_read: qcom_geni_serial_poll_bit+0x94/0x138 width=32 addr=0xfffffbfffdbff610 > rwmmio_post_read: qcom_geni_serial_poll_bit+0x94/0x138 width=32 val=0x0 addr=0xfffffbfffdbff610 > > Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org> > Co-developed-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com> > Signed-off-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com> > --- > arch/Kconfig | 3 ++ > arch/arm64/Kconfig | 1 + > include/trace/events/rwmmio.h | 97 +++++++++++++++++++++++++++++++++++ > lib/Kconfig | 7 +++ > lib/Makefile | 2 + > lib/trace_readwrite.c | 47 +++++++++++++++++ > 6 files changed, 157 insertions(+) > create mode 100644 include/trace/events/rwmmio.h > create mode 100644 lib/trace_readwrite.c How does this version look? Thanks, Sai
On Wed, 18 May 2022 22:14:14 +0530 Sai Prakash Ranjan <quic_saipraka@quicinc.com> wrote: > From: Prasad Sodagudi <psodagud@codeaurora.org> > > Generic MMIO read/write i.e., __raw_{read,write}{b,l,w,q} accessors > are typically used to read/write from/to memory mapped registers > and can cause hangs or some undefined behaviour in following few > cases, > > * If the access to the register space is unclocked, for example: if > there is an access to multimedia(MM) block registers without MM > clocks. > > * If the register space is protected and not set to be accessible from > non-secure world, for example: only EL3 (EL: Exception level) access > is allowed and any EL2/EL1 access is forbidden. > > * If xPU(memory/register protection units) is controlling access to > certain memory/register space for specific clients. > > and more... > > Such cases usually results in instant reboot/SErrors/NOC or interconnect > hangs and tracing these register accesses can be very helpful to debug > such issues during initial development stages and also in later stages. > > So use ftrace trace events to log such MMIO register accesses which > provides rich feature set such as early enablement of trace events, > filtering capability, dumping ftrace logs on console and many more. > > Sample output: > > rwmmio_write: __qcom_geni_serial_console_write+0x160/0x1e0 width=32 val=0xa0d5d addr=0xfffffbfffdbff700 > rwmmio_post_write: __qcom_geni_serial_console_write+0x160/0x1e0 width=32 val=0xa0d5d addr=0xfffffbfffdbff700 > rwmmio_read: qcom_geni_serial_poll_bit+0x94/0x138 width=32 addr=0xfffffbfffdbff610 > rwmmio_post_read: qcom_geni_serial_poll_bit+0x94/0x138 width=32 val=0x0 addr=0xfffffbfffdbff610 > > Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org> > Co-developed-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com> > Signed-off-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com> > ---
On 6/14/2022 8:02 PM, Steven Rostedt wrote: > On Wed, 18 May 2022 22:14:14 +0530 > Sai Prakash Ranjan <quic_saipraka@quicinc.com> wrote: > >> From: Prasad Sodagudi <psodagud@codeaurora.org> >> >> Generic MMIO read/write i.e., __raw_{read,write}{b,l,w,q} accessors >> are typically used to read/write from/to memory mapped registers >> and can cause hangs or some undefined behaviour in following few >> cases, >> >> * If the access to the register space is unclocked, for example: if >> there is an access to multimedia(MM) block registers without MM >> clocks. >> >> * If the register space is protected and not set to be accessible from >> non-secure world, for example: only EL3 (EL: Exception level) access >> is allowed and any EL2/EL1 access is forbidden. >> >> * If xPU(memory/register protection units) is controlling access to >> certain memory/register space for specific clients. >> >> and more... >> >> Such cases usually results in instant reboot/SErrors/NOC or interconnect >> hangs and tracing these register accesses can be very helpful to debug >> such issues during initial development stages and also in later stages. >> >> So use ftrace trace events to log such MMIO register accesses which >> provides rich feature set such as early enablement of trace events, >> filtering capability, dumping ftrace logs on console and many more. >> >> Sample output: >> >> rwmmio_write: __qcom_geni_serial_console_write+0x160/0x1e0 width=32 val=0xa0d5d addr=0xfffffbfffdbff700 >> rwmmio_post_write: __qcom_geni_serial_console_write+0x160/0x1e0 width=32 val=0xa0d5d addr=0xfffffbfffdbff700 >> rwmmio_read: qcom_geni_serial_poll_bit+0x94/0x138 width=32 addr=0xfffffbfffdbff610 >> rwmmio_post_read: qcom_geni_serial_poll_bit+0x94/0x138 width=32 val=0x0 addr=0xfffffbfffdbff610 >> >> Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org> >> Co-developed-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com> >> Signed-off-by: Sai Prakash Ranjan <quic_saipraka@quicinc.com> >> --- > From a tracing point of view, I do not see anything wrong with this patch. > > Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> > > -- Steve Thanks Steve. Hi Arnd, I hope we can take this series in your tree or let me know if anything else is pending? Thanks, Sai
diff --git a/arch/Kconfig b/arch/Kconfig index 31c4fdc4a4ba..5e7aa17ed609 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -1369,6 +1369,9 @@ config ARCH_HAS_ELFCORE_COMPAT config ARCH_HAS_PARANOID_L1D_FLUSH bool +config ARCH_HAVE_TRACE_MMIO_ACCESS + bool + config DYNAMIC_SIGFRAME bool diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 20ea89d9ac2f..926e1a252b6f 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -48,6 +48,7 @@ config ARM64 select ARCH_HAS_ZONE_DMA_SET if EXPERT select ARCH_HAVE_ELF_PROT select ARCH_HAVE_NMI_SAFE_CMPXCHG + select ARCH_HAVE_TRACE_MMIO_ACCESS select ARCH_INLINE_READ_LOCK if !PREEMPTION select ARCH_INLINE_READ_LOCK_BH if !PREEMPTION select ARCH_INLINE_READ_LOCK_IRQ if !PREEMPTION diff --git a/include/trace/events/rwmmio.h b/include/trace/events/rwmmio.h new file mode 100644 index 000000000000..de41159216c1 --- /dev/null +++ b/include/trace/events/rwmmio.h @@ -0,0 +1,97 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (c) 2021-2022 Qualcomm Innovation Center, Inc. All rights reserved. + */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM rwmmio + +#if !defined(_TRACE_RWMMIO_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_RWMMIO_H + +#include <linux/tracepoint.h> + +DECLARE_EVENT_CLASS(rwmmio_rw_template, + + TP_PROTO(unsigned long caller, u64 val, u8 width, volatile void __iomem *addr), + + TP_ARGS(caller, val, width, addr), + + TP_STRUCT__entry( + __field(unsigned long, caller) + __field(unsigned long, addr) + __field(u64, val) + __field(u8, width) + ), + + TP_fast_assign( + __entry->caller = caller; + __entry->val = val; + __entry->addr = (unsigned long)addr; + __entry->width = width; + ), + + TP_printk("%pS width=%d val=%#llx addr=%#lx", + (void *)__entry->caller, __entry->width, + __entry->val, __entry->addr) +); + +DEFINE_EVENT(rwmmio_rw_template, rwmmio_write, + TP_PROTO(unsigned long caller, u64 val, u8 width, volatile void __iomem *addr), + TP_ARGS(caller, val, width, addr) +); + +DEFINE_EVENT(rwmmio_rw_template, rwmmio_post_write, + TP_PROTO(unsigned long caller, u64 val, u8 width, volatile void __iomem *addr), + TP_ARGS(caller, val, width, addr) +); + +TRACE_EVENT(rwmmio_read, + + TP_PROTO(unsigned long caller, u8 width, const volatile void __iomem *addr), + + TP_ARGS(caller, width, addr), + + TP_STRUCT__entry( + __field(unsigned long, caller) + __field(unsigned long, addr) + __field(u8, width) + ), + + TP_fast_assign( + __entry->caller = caller; + __entry->addr = (unsigned long)addr; + __entry->width = width; + ), + + TP_printk("%pS width=%d addr=%#lx", + (void *)__entry->caller, __entry->width, __entry->addr) +); + +TRACE_EVENT(rwmmio_post_read, + + TP_PROTO(unsigned long caller, u64 val, u8 width, const volatile void __iomem *addr), + + TP_ARGS(caller, val, width, addr), + + TP_STRUCT__entry( + __field(unsigned long, caller) + __field(unsigned long, addr) + __field(u64, val) + __field(u8, width) + ), + + TP_fast_assign( + __entry->caller = caller; + __entry->val = val; + __entry->addr = (unsigned long)addr; + __entry->width = width; + ), + + TP_printk("%pS width=%d val=%#llx addr=%#lx", + (void *)__entry->caller, __entry->width, + __entry->val, __entry->addr) +); + +#endif /* _TRACE_RWMMIO_H */ + +#include <trace/define_trace.h> diff --git a/lib/Kconfig b/lib/Kconfig index 087e06b4cdfd..5e2fd075724f 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -118,6 +118,13 @@ config INDIRECT_IOMEM_FALLBACK mmio accesses when the IO memory address is not a registered emulated region. +config TRACE_MMIO_ACCESS + bool "Register read/write tracing" + depends on TRACING && ARCH_HAVE_TRACE_MMIO_ACCESS + help + Create tracepoints for MMIO read/write operations. These trace events + can be used for logging all MMIO read/write operations. + source "lib/crypto/Kconfig" config CRC_CCITT diff --git a/lib/Makefile b/lib/Makefile index 6b9ffc1bd1ee..3df7d24e65d2 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -151,6 +151,8 @@ lib-y += logic_pio.o lib-$(CONFIG_INDIRECT_IOMEM) += logic_iomem.o +obj-$(CONFIG_TRACE_MMIO_ACCESS) += trace_readwrite.o + obj-$(CONFIG_GENERIC_HWEIGHT) += hweight.o obj-$(CONFIG_BTREE) += btree.o diff --git a/lib/trace_readwrite.c b/lib/trace_readwrite.c new file mode 100644 index 000000000000..88637038b30c --- /dev/null +++ b/lib/trace_readwrite.c @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Register read and write tracepoints + * + * Copyright (c) 2021-2022 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#include <linux/ftrace.h> +#include <linux/module.h> +#include <asm-generic/io.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/rwmmio.h> + +#ifdef CONFIG_TRACE_MMIO_ACCESS +void log_write_mmio(u64 val, u8 width, volatile void __iomem *addr, + unsigned long caller_addr) +{ + trace_rwmmio_write(caller_addr, val, width, addr); +} +EXPORT_SYMBOL_GPL(log_write_mmio); +EXPORT_TRACEPOINT_SYMBOL_GPL(rwmmio_write); + +void log_post_write_mmio(u64 val, u8 width, volatile void __iomem *addr, + unsigned long caller_addr) +{ + trace_rwmmio_post_write(caller_addr, val, width, addr); +} +EXPORT_SYMBOL_GPL(log_post_write_mmio); +EXPORT_TRACEPOINT_SYMBOL_GPL(rwmmio_post_write); + +void log_read_mmio(u8 width, const volatile void __iomem *addr, + unsigned long caller_addr) +{ + trace_rwmmio_read(caller_addr, width, addr); +} +EXPORT_SYMBOL_GPL(log_read_mmio); +EXPORT_TRACEPOINT_SYMBOL_GPL(rwmmio_read); + +void log_post_read_mmio(u64 val, u8 width, const volatile void __iomem *addr, + unsigned long caller_addr) +{ + trace_rwmmio_post_read(caller_addr, val, width, addr); +} +EXPORT_SYMBOL_GPL(log_post_read_mmio); +EXPORT_TRACEPOINT_SYMBOL_GPL(rwmmio_post_read); +#endif /* CONFIG_TRACE_MMIO_ACCESS */