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trace: Add snapshot of ipc logging driver

Browse Source 
This snapshot is taken as of msm-4.19 'commit <5a4fd734e3e0>
("Merge "msm: audio: support for gapless_pcm"")'.

In addition, replace arch_counter_get_cntvct() with
__arch_counter_get_cntvct(), update copyrights and use simple_open
instead of creating redundant file operation functions.

Change-Id: I6336d21e2f6a385a6364aa518b74dca69771b783
Signed-off-by: Chris Lew <clew@codeaurora.org>
This commit is contained in:
Chris Lew
2019-07-02 19:49:44 -07:00
parent 944b9617af
commit 85bf042e5f
7 changed files with 1952 additions and 0 deletions
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361
Documentation/arm/msm/msm_ipc_logging.txt Normal file
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@@ -0,0 +1,361 @@
Introduction
============
This module will be used to log the events by any module/driver which
enables Inter Processor Communication (IPC). Some of the IPC drivers such
as Message Routers, Multiplexers etc. which act as a passive pipe need
some mechanism to log their events. Since all such IPC drivers handle a
large amount of traffic/events, using kernel logs renders kernel logs
unusable by other drivers and also degrades the performance of IPC
drivers. This new module will help in logging such high frequency IPC
driver events while keeping the standard kernel logging mechanism
intact.
Hardware description
====================
This module does not drive any hardware resource and will only use the
kernel memory-space to log the events.
Software description
====================
Design Goals
------------
This module is designed to
* support logging for drivers handling large amount of
traffic/events
* define & differentiate events/logs from different drivers
* support both id-based and stream-based logging
* support extracting the logs from both live target & memory dump
IPC Log Context
----------------
This module will support logging by multiple drivers. To differentiate
between the multiple drivers that are using this logging mechanism, each
driver will be assigned a unique context by this module. Associated with
each context is the logging space, dynamically allocated from the kernel
memory-space, specific to that context so that the events logged using that
context will not interfere with other contexts.
Event Logging
--------------
Every event will be logged as a <Type: Size: Value> combination. Type
field identifies the type of the event that is logged. Size field represents
the size of the log information. Value field represents the actual
information being logged. This approach will support both id-based logging
and stream-based logging. This approach will also support logging sub-events
of an event. This module will provide helper routines to encode/decode the
logs to/from this format.
Encode Context
---------------
Encode context is a temporary storage space that will be used by the client
drivers to log the events in <Type: Size: Value> format. The client drivers
will perform an encode start operation to initialize the encode context
data structure. Then the client drivers will log their events into the
encode context. Upon completion of event logging, the client drivers will
perform an encode end operation to finalize the encode context data
structure to be logged. Then this updated encode context data structure
will be written into the client driver's IPC Log Context. The maximum
event log size will be defined as 256 bytes.
Log Space
----------
Each context (Figure 1) has an associated log space, which is dynamically
allocated from the kernel memory-space. The log space is organized as a list of
1 or more kernel memory pages. Each page (Figure 2) contains header information
which is used to differentiate the log kernel page from the other kernel pages.
0 ---------------------------------
| magic_no = 0x25874452 |
---------------------------------
| nmagic_no = 0x52784425 |
---------------------------------
| version |
---------------------------------
| user_version |
---------------------------------
| log_id |
---------------------------------
| header_size |
---------------------------------
| |
| |
| name [20 chars] |
| |
| |
---------------------------------
| run-time data structures |
---------------------------------
Figure 1 - Log Context Structure
31 0
0 ---------------------------------
| magic_no = 0x52784425 |
---------------------------------
| nmagic_no = 0xAD87BBDA |
---------------------------------
|1| page_num |
---------------------------------
| read_offset | write_offset |
---------------------------------
| log_id |
---------------------------------
| start_time low word |
| start_time high word |
---------------------------------
| end_time low word |
| end_time high word |
---------------------------------
| context offset |
---------------------------------
| run-time data structures |
. . . . .
---------------------------------
| |
| Log Data |
. . .
. . .
| |
--------------------------------- PAGE_SIZE - 1
Figure 2 - Log Page Structure
In addition to extracting logs at runtime through DebugFS, IPC Logging has been
designed to allow extraction of logs from a memory dump. The magic numbers,
timestamps, and context offset are all added to support the memory-dump
extraction use case.
Design
======
Alternate solutions discussed include using kernel & SMEM logs which are
limited in size and hence using them render them unusable by other drivers.
Also kernel logging into serial console is slowing down the performance of
the drivers by multiple times and sometimes lead to APPs watchdog bite.
Power Management
================
Not-Applicable
SMP/multi-core
==============
This module uses spinlocks & mutexes to handle multi-core safety.
Security
========
Not-Applicable
Performance
===========
This logging mechanism, based on experimental data, is not expected to
cause a significant performance degradation. Under worst case, it can
cause 1 - 2 percent degradation in the throughput of the IPC Drivers.
Interface
=========
Exported Data Structures
------------------------
struct encode_context {
struct tsv_header hdr;
char buff[MAX_MSG_SIZE];
int offset;
};
struct decode_context {
int output_format;
char *buff;
int size;
};
Kernel-Space Interface APIs
----------------------------
/*
* ipc_log_context_create: Create a ipc log context
*
* @max_num_pages: Number of pages of logging space required (max. 10)
* @mod_name : Name of the directory entry under DEBUGFS
* @user_version : Version number of user-defined message formats
*
* returns reference to context on success, NULL on failure
*/
void *ipc_log_context_create(int max_num_pages, const char *mod_name,
uint16_t user_version);
/*
* msg_encode_start: Start encoding a log message
*
* @ectxt: Temporary storage to hold the encoded message
* @type: Root event type defined by the module which is logging
*/
void msg_encode_start(struct encode_context *ectxt, uint32_t type);
/*
* msg_encode_end: Complete the message encode process
*
* @ectxt: Temporary storage which holds the encoded message
*/
void msg_encode_end(struct encode_context *ectxt);
/*
* tsv_timestamp_write: Writes the current timestamp count
*
* @ectxt: Context initialized by calling msg_encode_start()
*
* Returns 0 on success, -ve error code on failure
*/
int tsv_timestamp_write(struct encode_context *ectxt);
/*
* tsv_pointer_write: Writes a data pointer
*
* @ectxt: Context initialized by calling msg_encode_start()
* @pointer: Pointer value to write
*
* Returns 0 on success, -ve error code on failure
*/
int tsv_pointer_write(struct encode_context *ectxt, void *pointer);
/*
* tsv_int32_write: Writes a 32-bit integer value
*
* @ectxt: Context initialized by calling msg_encode_start()
* @n: Integer to write
*
* Returns 0 on success, -ve error code on failure
*/
int tsv_int32_write(struct encode_context *ectxt, int32_t n);
/*
* tsv_byte_array_write: Writes a byte array
*
* @ectxt: Context initialized by calling msg_encode_start()
* @data: Location of data
* @data_size: Size of data to be written
*
* Returns 0 on success, -ve error code on failure
*/
int tsv_byte_array_write(struct encode_context *ectxt,
void *data, int data_size);
/*
* ipc_log_write: Write the encoded message into the log space
*
* @ctxt: IPC log context where the message has to be logged into
* @ectxt: Temporary storage containing the encoded message
*/
void ipc_log_write(unsigned long ctxt, struct encode_context *ectxt);
/*
* ipc_log_string: Helper function to log a string
*
* @dlctxt: IPC Log Context created using ipc_log_context_create()
* @fmt: Data specified using format specifiers
*/
int ipc_log_string(unsigned long dlctxt, const char *fmt, ...);
/*
* tsv_timestamp_read: Reads a timestamp
*
* @ectxt: Context retrieved by reading from log space
* @dctxt: Temporary storage to hold the decoded message
* @format: Output format while dumping through DEBUGFS
*/
void tsv_timestamp_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format);
/*
* tsv_pointer_read: Reads a data pointer
*
* @ectxt: Context retrieved by reading from log space
* @dctxt: Temporary storage to hold the decoded message
* @format: Output format while dumping through DEBUGFS
*/
void tsv_pointer_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format);
/*
* tsv_int32_read: Reads a 32-bit integer value
*
* @ectxt: Context retrieved by reading from log space
* @dctxt: Temporary storage to hold the decoded message
* @format: Output format while dumping through DEBUGFS
*/
void tsv_int32_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format);
/*
* tsv_byte_array_read: Reads a byte array/string
*
* @ectxt: Context retrieved by reading from log space
* @dctxt: Temporary storage to hold the decoded message
* @format: Output format while dumping through DEBUGFS
*/
void tsv_byte_array_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format);
/*
* add_deserialization_func: Register a deserialization function to
* to unpack the subevents of a main event
*
* @ctxt: IPC log context to which the deserialization function has
* to be registered
* @type: Main/Root event, defined by the module which is logging, to
* which this deserialization function has to be registered.
* @dfune: Deserialization function to be registered
*
* return 0 on success, -ve value on FAILURE
*/
int add_deserialization_func(unsigned long ctxt, int type,
void (*dfunc)(struct encode_context *,
struct decode_context *));
Driver parameters
=================
Not-Applicable
Config options
==============
Not-Applicable
Dependencies
============
This module will partially depend on CONFIG_DEBUGFS, in order to dump the
logs through debugfs. If CONFIG_DEBUGFS is disabled, the above mentioned
helper functions will perform no operation and return appropriate error
code if the return value is non void. Under such circumstances the logs can
only be extracted through the memory dump.
User space utilities
====================
DEBUGFS
Other
=====
Not-Applicable
Known issues
============
None
To do
=====
None

285
include/linux/ipc_logging.h Normal file
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@@ -0,0 +1,285 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2012-2015,2017 The Linux Foundation. All rights reserved.
*/
#ifndef _IPC_LOGGING_H
#define _IPC_LOGGING_H
#include <linux/types.h>
#define MAX_MSG_SIZE 255
enum {
TSV_TYPE_MSG_START = 1,
TSV_TYPE_SKB = TSV_TYPE_MSG_START,
TSV_TYPE_STRING,
TSV_TYPE_MSG_END = TSV_TYPE_STRING,
};
struct tsv_header {
unsigned char type;
unsigned char size; /* size of data field */
};
struct encode_context {
struct tsv_header hdr;
char buff[MAX_MSG_SIZE];
int offset;
};
struct decode_context {
int output_format; /* 0 = debugfs */
char *buff; /* output buffer */
int size; /* size of output buffer */
};
#if defined(CONFIG_IPC_LOGGING)
/*
* ipc_log_context_create: Create a debug log context
* Should not be called from atomic context
*
* @max_num_pages: Number of pages of logging space required (max. 10)
* @mod_name : Name of the directory entry under DEBUGFS
* @user_version : Version number of user-defined message formats
*
* returns context id on success, NULL on failure
*/
void *ipc_log_context_create(int max_num_pages, const char *modname,
uint16_t user_version);
/*
* msg_encode_start: Start encoding a log message
*
* @ectxt: Temporary storage to hold the encoded message
* @type: Root event type defined by the module which is logging
*/
void msg_encode_start(struct encode_context *ectxt, uint32_t type);
/*
* tsv_timestamp_write: Writes the current timestamp count
*
* @ectxt: Context initialized by calling msg_encode_start()
*/
int tsv_timestamp_write(struct encode_context *ectxt);
/*
* tsv_qtimer_write: Writes the current QTimer timestamp count
*
* @ectxt: Context initialized by calling msg_encode_start()
*/
int tsv_qtimer_write(struct encode_context *ectxt);
/*
* tsv_pointer_write: Writes a data pointer
*
* @ectxt: Context initialized by calling msg_encode_start()
* @pointer: Pointer value to write
*/
int tsv_pointer_write(struct encode_context *ectxt, void *pointer);
/*
* tsv_int32_write: Writes a 32-bit integer value
*
* @ectxt: Context initialized by calling msg_encode_start()
* @n: Integer to write
*/
int tsv_int32_write(struct encode_context *ectxt, int32_t n);
/*
* tsv_byte_array_write: Writes a byte array
*
* @ectxt: Context initialized by calling msg_encode_start()
* @data: Pointer to byte array
* @data_size: Size of byte array
*/
int tsv_byte_array_write(struct encode_context *ectxt,
void *data, int data_size);
/*
* msg_encode_end: Complete the message encode process
*
* @ectxt: Temporary storage which holds the encoded message
*/
void msg_encode_end(struct encode_context *ectxt);
/*
* ipc_log_write: Commits message to logging ring buffer
*
* @ctxt: Logging context
* @ectxt: Temporary storage which holds the encoded message
*/
void ipc_log_write(void *ctxt, struct encode_context *ectxt);
/*
* ipc_log_string: Helper function to log a string
*
* @ilctxt: Debug Log Context created using ipc_log_context_create()
* @fmt: Data specified using format specifiers
*/
int ipc_log_string(void *ilctxt, const char *fmt, ...) __printf(2, 3);
/**
* ipc_log_extract - Reads and deserializes log
*
* @ilctxt: logging context
* @buff: buffer to receive the data
* @size: size of the buffer
* @returns: 0 if no data read; >0 number of bytes read; < 0 error
*
* If no data is available to be read, then the ilctxt::read_avail
* completion is reinitialized. This allows clients to block
* until new log data is save.
*/
int ipc_log_extract(void *ilctxt, char *buff, int size);
/*
* Print a string to decode context.
* @dctxt Decode context
* @args printf args
*/
#define IPC_SPRINTF_DECODE(dctxt, args...) \
do { \
int i; \
i = scnprintf(dctxt->buff, dctxt->size, args); \
dctxt->buff += i; \
dctxt->size -= i; \
} while (0)
/*
* tsv_timestamp_read: Reads a timestamp
*
* @ectxt: Context retrieved by reading from log space
* @dctxt: Temporary storage to hold the decoded message
* @format: Output format while dumping through DEBUGFS
*/
void tsv_timestamp_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format);
/*
* tsv_qtimer_read: Reads a QTimer timestamp
*
* @ectxt: Context retrieved by reading from log space
* @dctxt: Temporary storage to hold the decoded message
* @format: Output format while dumping through DEBUGFS
*/
void tsv_qtimer_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format);
/*
* tsv_pointer_read: Reads a data pointer
*
* @ectxt: Context retrieved by reading from log space
* @dctxt: Temporary storage to hold the decoded message
* @format: Output format while dumping through DEBUGFS
*/
void tsv_pointer_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format);
/*
* tsv_int32_read: Reads a 32-bit integer value
*
* @ectxt: Context retrieved by reading from log space
* @dctxt: Temporary storage to hold the decoded message
* @format: Output format while dumping through DEBUGFS
*/
int32_t tsv_int32_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format);
/*
* tsv_byte_array_read: Reads a byte array
*
* @ectxt: Context retrieved by reading from log space
* @dctxt: Temporary storage to hold the decoded message
* @format: Output format while dumping through DEBUGFS
*/
void tsv_byte_array_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format);
/*
* add_deserialization_func: Register a deserialization function to
* to unpack the subevents of a main event
*
* @ctxt: Debug log context to which the deserialization function has
* to be registered
* @type: Main/Root event, defined by the module which is logging, to
* which this deserialization function has to be registered.
* @dfune: Deserialization function to be registered
*
* return 0 on success, -ve value on FAILURE
*/
int add_deserialization_func(void *ctxt, int type,
void (*dfunc)(struct encode_context *,
struct decode_context *));
/*
* ipc_log_context_destroy: Destroy debug log context
*
* @ctxt: debug log context created by calling ipc_log_context_create API.
*/
int ipc_log_context_destroy(void *ctxt);
#else
static inline void *ipc_log_context_create(int max_num_pages,
const char *modname, uint16_t user_version)
{ return NULL; }
static inline void msg_encode_start(struct encode_context *ectxt,
uint32_t type) { }
static inline int tsv_timestamp_write(struct encode_context *ectxt)
{ return -EINVAL; }
static inline int tsv_qtimer_write(struct encode_context *ectxt)
{ return -EINVAL; }
static inline int tsv_pointer_write(struct encode_context *ectxt, void *pointer)
{ return -EINVAL; }
static inline int tsv_int32_write(struct encode_context *ectxt, int32_t n)
{ return -EINVAL; }
static inline int tsv_byte_array_write(struct encode_context *ectxt,
void *data, int data_size)
{ return -EINVAL; }
static inline void msg_encode_end(struct encode_context *ectxt) { }
static inline void ipc_log_write(void *ctxt, struct encode_context *ectxt) { }
static inline int ipc_log_string(void *ilctxt, const char *fmt, ...)
{ return -EINVAL; }
static inline int ipc_log_extract(void *ilctxt, char *buff, int size)
{ return -EINVAL; }
#define IPC_SPRINTF_DECODE(dctxt, args...) do { } while (0)
static inline void tsv_timestamp_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format) { }
static inline void tsv_qtimer_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format) { }
static inline void tsv_pointer_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format) { }
static inline int32_t tsv_int32_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format)
{ return 0; }
static inline void tsv_byte_array_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format) { }
static inline int add_deserialization_func(void *ctxt, int type,
void (*dfunc)(struct encode_context *,
struct decode_context *))
{ return 0; }
static inline int ipc_log_context_destroy(void *ctxt)
{ return 0; }
#endif
#endif

11
kernel/trace/Kconfig
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@@ -88,6 +88,17 @@ config RING_BUFFER_ALLOW_SWAP
Allow the use of ring_buffer_swap_cpu. Allow the use of ring_buffer_swap_cpu.
Adds a very slight overhead to tracing when enabled. Adds a very slight overhead to tracing when enabled.
config IPC_LOGGING
bool "Debug Logging for IPC Drivers"
select GENERIC_TRACER
help
IPC Logging driver provides a logging option for IPC Drivers.
This provides a cyclic buffer based logging support in a driver
specific context. This driver also provides a debugfs interface
to dump the logs in a live fashion.
If in doubt, say no.
config PREEMPTIRQ_TRACEPOINTS config PREEMPTIRQ_TRACEPOINTS
bool bool
depends on TRACE_PREEMPT_TOGGLE || TRACE_IRQFLAGS depends on TRACE_PREEMPT_TOGGLE || TRACE_IRQFLAGS

4
kernel/trace/Makefile
View File

@@ -85,4 +85,8 @@ obj-$(CONFIG_UPROBE_EVENTS) += trace_uprobe.o
obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o obj-$(CONFIG_TRACEPOINT_BENCHMARK) += trace_benchmark.o
obj-$(CONFIG_IPC_LOGGING) += ipc_logging.o
ifdef CONFIG_DEBUG_FS
obj-$(CONFIG_IPC_LOGGING) += ipc_logging_debug.o
endif
libftrace-y := ftrace.o libftrace-y := ftrace.o

934
kernel/trace/ipc_logging.c Normal file
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@@ -0,0 +1,934 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2012-2019, The Linux Foundation. All rights reserved.
*/
#include <asm/arch_timer.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/jiffies.h>
#include <linux/debugfs.h>
#include <linux/io.h>
#include <linux/idr.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/sched/clock.h>
#include <linux/ipc_logging.h>
#include "ipc_logging_private.h"
#define LOG_PAGE_DATA_SIZE sizeof(((struct ipc_log_page *)0)->data)
#define LOG_PAGE_FLAG (1 << 31)
static LIST_HEAD(ipc_log_context_list);
static DEFINE_RWLOCK(context_list_lock_lha1);
static void *get_deserialization_func(struct ipc_log_context *ilctxt,
int type);
static struct ipc_log_page *get_first_page(struct ipc_log_context *ilctxt)
{
struct ipc_log_page_header *p_pghdr;
struct ipc_log_page *pg = NULL;
if (!ilctxt)
return NULL;
p_pghdr = list_first_entry(&ilctxt->page_list,
struct ipc_log_page_header, list);
pg = container_of(p_pghdr, struct ipc_log_page, hdr);
return pg;
}
/**
* is_nd_read_empty - Returns true if no data is available to read in log
*
* @ilctxt: logging context
* @returns: > 1 if context is empty; 0 if not empty; <0 for failure
*
* This is for the debugfs read pointer which allows for a non-destructive read.
* There may still be data in the log, but it may have already been read.
*/
static int is_nd_read_empty(struct ipc_log_context *ilctxt)
{
if (!ilctxt)
return -EINVAL;
return ((ilctxt->nd_read_page == ilctxt->write_page) &&
(ilctxt->nd_read_page->hdr.nd_read_offset ==
ilctxt->write_page->hdr.write_offset));
}
/**
* is_read_empty - Returns true if no data is available in log
*
* @ilctxt: logging context
* @returns: > 1 if context is empty; 0 if not empty; <0 for failure
*
* This is for the actual log contents. If it is empty, then there
* is no data at all in the log.
*/
static int is_read_empty(struct ipc_log_context *ilctxt)
{
if (!ilctxt)
return -EINVAL;
return ((ilctxt->read_page == ilctxt->write_page) &&
(ilctxt->read_page->hdr.read_offset ==
ilctxt->write_page->hdr.write_offset));
}
/**
* is_nd_read_equal_read - Return true if the non-destructive read is equal to
* the destructive read
*
* @ilctxt: logging context
* @returns: true if nd read is equal to read; false otherwise
*/
static bool is_nd_read_equal_read(struct ipc_log_context *ilctxt)
{
uint16_t read_offset;
uint16_t nd_read_offset;
if (ilctxt->nd_read_page == ilctxt->read_page) {
read_offset = ilctxt->read_page->hdr.read_offset;
nd_read_offset = ilctxt->nd_read_page->hdr.nd_read_offset;
if (read_offset == nd_read_offset)
return true;
}
return false;
}
static struct ipc_log_page *get_next_page(struct ipc_log_context *ilctxt,
struct ipc_log_page *cur_pg)
{
struct ipc_log_page_header *p_pghdr;
struct ipc_log_page *pg = NULL;
if (!ilctxt || !cur_pg)
return NULL;
if (ilctxt->last_page == cur_pg)
return ilctxt->first_page;
p_pghdr = list_first_entry(&cur_pg->hdr.list,
struct ipc_log_page_header, list);
pg = container_of(p_pghdr, struct ipc_log_page, hdr);
return pg;
}
/**
* ipc_log_read - do non-destructive read of the log
*
* @ilctxt: Logging context
* @data: Data pointer to receive the data
* @data_size: Number of bytes to read (must be <= bytes available in log)
*
* This read will update a runtime read pointer, but will not affect the actual
* contents of the log which allows for reading the logs continuously while
* debugging and if the system crashes, then the full logs can still be
* extracted.
*/
static void ipc_log_read(struct ipc_log_context *ilctxt,
void *data, int data_size)
{
int bytes_to_read;
bytes_to_read = MIN(LOG_PAGE_DATA_SIZE
- ilctxt->nd_read_page->hdr.nd_read_offset,
data_size);
memcpy(data, (ilctxt->nd_read_page->data +
ilctxt->nd_read_page->hdr.nd_read_offset), bytes_to_read);
if (bytes_to_read != data_size) {
/* not enough space, wrap read to next page */
ilctxt->nd_read_page->hdr.nd_read_offset = 0;
ilctxt->nd_read_page = get_next_page(ilctxt,
ilctxt->nd_read_page);
if (WARN_ON(ilctxt->nd_read_page == NULL))
return;
memcpy((data + bytes_to_read),
(ilctxt->nd_read_page->data +
ilctxt->nd_read_page->hdr.nd_read_offset),
(data_size - bytes_to_read));
bytes_to_read = (data_size - bytes_to_read);
}
ilctxt->nd_read_page->hdr.nd_read_offset += bytes_to_read;
}
/**
* ipc_log_drop - do destructive read of the log
*
* @ilctxt: Logging context
* @data: Data pointer to receive the data (or NULL)
* @data_size: Number of bytes to read (must be <= bytes available in log)
*/
static void ipc_log_drop(struct ipc_log_context *ilctxt, void *data,
int data_size)
{
int bytes_to_read;
bool push_nd_read;
bytes_to_read = MIN(LOG_PAGE_DATA_SIZE
- ilctxt->read_page->hdr.read_offset,
data_size);
if (data)
memcpy(data, (ilctxt->read_page->data +
ilctxt->read_page->hdr.read_offset), bytes_to_read);
if (bytes_to_read != data_size) {
/* not enough space, wrap read to next page */
push_nd_read = is_nd_read_equal_read(ilctxt);
ilctxt->read_page->hdr.read_offset = 0;
if (push_nd_read) {
ilctxt->read_page->hdr.nd_read_offset = 0;
ilctxt->read_page = get_next_page(ilctxt,
ilctxt->read_page);
if (WARN_ON(ilctxt->read_page == NULL))
return;
ilctxt->nd_read_page = ilctxt->read_page;
} else {
ilctxt->read_page = get_next_page(ilctxt,
ilctxt->read_page);
if (WARN_ON(ilctxt->read_page == NULL))
return;
}
if (data)
memcpy((data + bytes_to_read),
(ilctxt->read_page->data +
ilctxt->read_page->hdr.read_offset),
(data_size - bytes_to_read));
bytes_to_read = (data_size - bytes_to_read);
}
/* update non-destructive read pointer if necessary */
push_nd_read = is_nd_read_equal_read(ilctxt);
ilctxt->read_page->hdr.read_offset += bytes_to_read;
ilctxt->write_avail += data_size;
if (push_nd_read)
ilctxt->nd_read_page->hdr.nd_read_offset += bytes_to_read;
}
/**
* msg_read - Reads a message.
*
* If a message is read successfully, then the message context
* will be set to:
* .hdr message header .size and .type values
* .offset beginning of message data
*
* @ilctxt Logging context
* @ectxt Message context
*
* @returns 0 - no message available; >0 message size; <0 error
*/
static int msg_read(struct ipc_log_context *ilctxt,
struct encode_context *ectxt)
{
struct tsv_header hdr;
if (!ectxt)
return -EINVAL;
if (is_nd_read_empty(ilctxt))
return 0;
ipc_log_read(ilctxt, &hdr, sizeof(hdr));
ectxt->hdr.type = hdr.type;
ectxt->hdr.size = hdr.size;
ectxt->offset = sizeof(hdr);
ipc_log_read(ilctxt, (ectxt->buff + ectxt->offset),
(int)hdr.size);
return sizeof(hdr) + (int)hdr.size;
}
/**
* msg_drop - Drops a message.
*
* @ilctxt Logging context
*/
static void msg_drop(struct ipc_log_context *ilctxt)
{
struct tsv_header hdr;
if (!is_read_empty(ilctxt)) {
ipc_log_drop(ilctxt, &hdr, sizeof(hdr));
ipc_log_drop(ilctxt, NULL, (int)hdr.size);
}
}
/*
* Commits messages to the FIFO. If the FIFO is full, then enough
* messages are dropped to create space for the new message.
*/
void ipc_log_write(void *ctxt, struct encode_context *ectxt)
{
struct ipc_log_context *ilctxt = (struct ipc_log_context *)ctxt;
int bytes_to_write;
unsigned long flags;
if (!ilctxt || !ectxt) {
pr_err("%s: Invalid ipc_log or encode context\n", __func__);
return;
}
read_lock_irqsave(&context_list_lock_lha1, flags);
spin_lock(&ilctxt->context_lock_lhb1);
while (ilctxt->write_avail <= ectxt->offset)
msg_drop(ilctxt);
bytes_to_write = MIN(LOG_PAGE_DATA_SIZE
- ilctxt->write_page->hdr.write_offset,
ectxt->offset);
memcpy((ilctxt->write_page->data +
ilctxt->write_page->hdr.write_offset),
ectxt->buff, bytes_to_write);
if (bytes_to_write != ectxt->offset) {
uint64_t t_now = sched_clock();
ilctxt->write_page->hdr.write_offset += bytes_to_write;
ilctxt->write_page->hdr.end_time = t_now;
ilctxt->write_page = get_next_page(ilctxt, ilctxt->write_page);
if (WARN_ON(ilctxt->write_page == NULL)) {
spin_unlock(&ilctxt->context_lock_lhb1);
read_unlock_irqrestore(&context_list_lock_lha1, flags);
return;
}
ilctxt->write_page->hdr.write_offset = 0;
ilctxt->write_page->hdr.start_time = t_now;
memcpy((ilctxt->write_page->data +
ilctxt->write_page->hdr.write_offset),
(ectxt->buff + bytes_to_write),
(ectxt->offset - bytes_to_write));
bytes_to_write = (ectxt->offset - bytes_to_write);
}
ilctxt->write_page->hdr.write_offset += bytes_to_write;
ilctxt->write_avail -= ectxt->offset;
complete(&ilctxt->read_avail);
spin_unlock(&ilctxt->context_lock_lhb1);
read_unlock_irqrestore(&context_list_lock_lha1, flags);
}
EXPORT_SYMBOL(ipc_log_write);
/*
* Starts a new message after which you can add serialized data and
* then complete the message by calling msg_encode_end().
*/
void msg_encode_start(struct encode_context *ectxt, uint32_t type)
{
if (!ectxt) {
pr_err("%s: Invalid encode context\n", __func__);
return;
}
ectxt->hdr.type = type;
ectxt->hdr.size = 0;
ectxt->offset = sizeof(ectxt->hdr);
}
EXPORT_SYMBOL(msg_encode_start);
/*
* Completes the message
*/
void msg_encode_end(struct encode_context *ectxt)
{
if (!ectxt) {
pr_err("%s: Invalid encode context\n", __func__);
return;
}
/* finalize data size */
ectxt->hdr.size = ectxt->offset - sizeof(ectxt->hdr);
memcpy(ectxt->buff, &ectxt->hdr, sizeof(ectxt->hdr));
}
EXPORT_SYMBOL(msg_encode_end);
/*
* Helper function used to write data to a message context.
*
* @ectxt context initialized by calling msg_encode_start()
* @data data to write
* @size number of bytes of data to write
*/
static inline int tsv_write_data(struct encode_context *ectxt,
void *data, uint32_t size)
{
if (!ectxt) {
pr_err("%s: Invalid encode context\n", __func__);
return -EINVAL;
}
if ((ectxt->offset + size) > MAX_MSG_SIZE) {
pr_err("%s: No space to encode further\n", __func__);
return -EINVAL;
}
memcpy((void *)(ectxt->buff + ectxt->offset), data, size);
ectxt->offset += size;
return 0;
}
/*
* Helper function that writes a type to the context.
*
* @ectxt context initialized by calling msg_encode_start()
* @type primitive type
* @size size of primitive in bytes
*/
static inline int tsv_write_header(struct encode_context *ectxt,
uint32_t type, uint32_t size)
{
struct tsv_header hdr;
hdr.type = (unsigned char)type;
hdr.size = (unsigned char)size;
return tsv_write_data(ectxt, &hdr, sizeof(hdr));
}
/*
* Writes the current timestamp count.
*
* @ectxt context initialized by calling msg_encode_start()
*/
int tsv_timestamp_write(struct encode_context *ectxt)
{
int ret;
uint64_t t_now = sched_clock();
ret = tsv_write_header(ectxt, TSV_TYPE_TIMESTAMP, sizeof(t_now));
if (ret)
return ret;
return tsv_write_data(ectxt, &t_now, sizeof(t_now));
}
EXPORT_SYMBOL(tsv_timestamp_write);
/*
* Writes the current QTimer timestamp count.
*
* @ectxt context initialized by calling msg_encode_start()
*/
int tsv_qtimer_write(struct encode_context *ectxt)
{
int ret;
uint64_t t_now = __arch_counter_get_cntvct();
ret = tsv_write_header(ectxt, TSV_TYPE_QTIMER, sizeof(t_now));
if (ret)
return ret;
return tsv_write_data(ectxt, &t_now, sizeof(t_now));
}
EXPORT_SYMBOL(tsv_qtimer_write);
/*
* Writes a data pointer.
*
* @ectxt context initialized by calling msg_encode_start()
* @pointer pointer value to write
*/
int tsv_pointer_write(struct encode_context *ectxt, void *pointer)
{
int ret;
ret = tsv_write_header(ectxt, TSV_TYPE_POINTER, sizeof(pointer));
if (ret)
return ret;
return tsv_write_data(ectxt, &pointer, sizeof(pointer));
}
EXPORT_SYMBOL(tsv_pointer_write);
/*
* Writes a 32-bit integer value.
*
* @ectxt context initialized by calling msg_encode_start()
* @n integer to write
*/
int tsv_int32_write(struct encode_context *ectxt, int32_t n)
{
int ret;
ret = tsv_write_header(ectxt, TSV_TYPE_INT32, sizeof(n));
if (ret)
return ret;
return tsv_write_data(ectxt, &n, sizeof(n));
}
EXPORT_SYMBOL(tsv_int32_write);
/*
* Writes a byte array.
*
* @ectxt context initialized by calling msg_write_start()
* @data Beginning address of data
* @data_size Size of data to be written
*/
int tsv_byte_array_write(struct encode_context *ectxt,
void *data, int data_size)
{
int ret;
ret = tsv_write_header(ectxt, TSV_TYPE_BYTE_ARRAY, data_size);
if (ret)
return ret;
return tsv_write_data(ectxt, data, data_size);
}
EXPORT_SYMBOL(tsv_byte_array_write);
/*
* Helper function to log a string
*
* @ilctxt ipc_log_context created using ipc_log_context_create()
* @fmt Data specified using format specifiers
*/
int ipc_log_string(void *ilctxt, const char *fmt, ...)
{
struct encode_context ectxt;
int avail_size, data_size, hdr_size = sizeof(struct tsv_header);
va_list arg_list;
if (!ilctxt)
return -EINVAL;
msg_encode_start(&ectxt, TSV_TYPE_STRING);
tsv_timestamp_write(&ectxt);
tsv_qtimer_write(&ectxt);
avail_size = (MAX_MSG_SIZE - (ectxt.offset + hdr_size));
va_start(arg_list, fmt);
data_size = vscnprintf((ectxt.buff + ectxt.offset + hdr_size),
avail_size, fmt, arg_list);
va_end(arg_list);
tsv_write_header(&ectxt, TSV_TYPE_BYTE_ARRAY, data_size);
ectxt.offset += data_size;
msg_encode_end(&ectxt);
ipc_log_write(ilctxt, &ectxt);
return 0;
}
EXPORT_SYMBOL(ipc_log_string);
/**
* ipc_log_extract - Reads and deserializes log
*
* @ctxt: logging context
* @buff: buffer to receive the data
* @size: size of the buffer
* @returns: 0 if no data read; >0 number of bytes read; < 0 error
*
* If no data is available to be read, then the ilctxt::read_avail
* completion is reinitialized. This allows clients to block
* until new log data is save.
*/
int ipc_log_extract(void *ctxt, char *buff, int size)
{
struct encode_context ectxt;
struct decode_context dctxt;
void (*deserialize_func)(struct encode_context *ectxt,
struct decode_context *dctxt);
struct ipc_log_context *ilctxt = (struct ipc_log_context *)ctxt;
unsigned long flags;
int ret;
if (size < MAX_MSG_DECODED_SIZE)
return -EINVAL;
dctxt.output_format = OUTPUT_DEBUGFS;
dctxt.buff = buff;
dctxt.size = size;
read_lock_irqsave(&context_list_lock_lha1, flags);
spin_lock(&ilctxt->context_lock_lhb1);
if (ilctxt->destroyed) {
ret = -EIO;
goto done;
}
while (dctxt.size >= MAX_MSG_DECODED_SIZE &&
!is_nd_read_empty(ilctxt)) {
msg_read(ilctxt, &ectxt);
deserialize_func = get_deserialization_func(ilctxt,
ectxt.hdr.type);
spin_unlock(&ilctxt->context_lock_lhb1);
read_unlock_irqrestore(&context_list_lock_lha1, flags);
if (deserialize_func)
deserialize_func(&ectxt, &dctxt);
else
pr_err("%s: unknown message 0x%x\n",
__func__, ectxt.hdr.type);
read_lock_irqsave(&context_list_lock_lha1, flags);
spin_lock(&ilctxt->context_lock_lhb1);
}
ret = size - dctxt.size;
if (ret == 0) {
if (!ilctxt->destroyed)
reinit_completion(&ilctxt->read_avail);
else
ret = -EIO;
}
done:
spin_unlock(&ilctxt->context_lock_lhb1);
read_unlock_irqrestore(&context_list_lock_lha1, flags);
return ret;
}
EXPORT_SYMBOL(ipc_log_extract);
/*
* Helper function used to read data from a message context.
*
* @ectxt context initialized by calling msg_read()
* @data data to read
* @size number of bytes of data to read
*/
static void tsv_read_data(struct encode_context *ectxt,
void *data, uint32_t size)
{
if (WARN_ON((ectxt->offset + size) > MAX_MSG_SIZE)) {
memcpy(data, (ectxt->buff + ectxt->offset),
MAX_MSG_SIZE - ectxt->offset - 1);
ectxt->offset += MAX_MSG_SIZE - ectxt->offset - 1;
return;
}
memcpy(data, (ectxt->buff + ectxt->offset), size);
ectxt->offset += size;
}
/*
* Helper function that reads a type from the context and updates the
* context pointers.
*
* @ectxt context initialized by calling msg_read()
* @hdr type header
*/
static void tsv_read_header(struct encode_context *ectxt,
struct tsv_header *hdr)
{
if (WARN_ON((ectxt->offset + sizeof(*hdr)) > MAX_MSG_SIZE)) {
memcpy(hdr, (ectxt->buff + ectxt->offset),
MAX_MSG_SIZE - ectxt->offset - 1);
ectxt->offset += MAX_MSG_SIZE - ectxt->offset - 1;
return;
}
memcpy(hdr, (ectxt->buff + ectxt->offset), sizeof(*hdr));
ectxt->offset += sizeof(*hdr);
}
/*
* Reads a timestamp.
*
* @ectxt context initialized by calling msg_read()
* @dctxt deserialization context
* @format output format (appended to %6u.09u timestamp format)
*/
void tsv_timestamp_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format)
{
struct tsv_header hdr;
uint64_t val;
unsigned long nanosec_rem;
tsv_read_header(ectxt, &hdr);
if (WARN_ON(hdr.type != TSV_TYPE_TIMESTAMP))
return;
tsv_read_data(ectxt, &val, sizeof(val));
nanosec_rem = do_div(val, 1000000000U);
IPC_SPRINTF_DECODE(dctxt, "[%6u.%09lu%s/",
(unsigned int)val, nanosec_rem, format);
}
EXPORT_SYMBOL(tsv_timestamp_read);
/*
* Reads a QTimer timestamp.
*
* @ectxt context initialized by calling msg_read()
* @dctxt deserialization context
* @format output format (appended to %#18llx timestamp format)
*/
void tsv_qtimer_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format)
{
struct tsv_header hdr;
uint64_t val;
tsv_read_header(ectxt, &hdr);
if (WARN_ON(hdr.type != TSV_TYPE_QTIMER))
return;
tsv_read_data(ectxt, &val, sizeof(val));
/*
* This gives 16 hex digits of output. The # prefix prepends
* a 0x, and these characters count as part of the number.
*/
IPC_SPRINTF_DECODE(dctxt, "%#18llx]%s", val, format);
}
EXPORT_SYMBOL(tsv_qtimer_read);
/*
* Reads a data pointer.
*
* @ectxt context initialized by calling msg_read()
* @dctxt deserialization context
* @format output format
*/
void tsv_pointer_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format)
{
struct tsv_header hdr;
void *val;
tsv_read_header(ectxt, &hdr);
if (WARN_ON(hdr.type != TSV_TYPE_POINTER))
return;
tsv_read_data(ectxt, &val, sizeof(val));
IPC_SPRINTF_DECODE(dctxt, format, val);
}
EXPORT_SYMBOL(tsv_pointer_read);
/*
* Reads a 32-bit integer value.
*
* @ectxt context initialized by calling msg_read()
* @dctxt deserialization context
* @format output format
*/
int32_t tsv_int32_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format)
{
struct tsv_header hdr;
int32_t val;
tsv_read_header(ectxt, &hdr);
if (WARN_ON(hdr.type != TSV_TYPE_INT32))
return -EINVAL;
tsv_read_data(ectxt, &val, sizeof(val));
IPC_SPRINTF_DECODE(dctxt, format, val);
return val;
}
EXPORT_SYMBOL(tsv_int32_read);
/*
* Reads a byte array/string.
*
* @ectxt context initialized by calling msg_read()
* @dctxt deserialization context
* @format output format
*/
void tsv_byte_array_read(struct encode_context *ectxt,
struct decode_context *dctxt, const char *format)
{
struct tsv_header hdr;
tsv_read_header(ectxt, &hdr);
if (WARN_ON(hdr.type != TSV_TYPE_BYTE_ARRAY))
return;
tsv_read_data(ectxt, dctxt->buff, hdr.size);
dctxt->buff += hdr.size;
dctxt->size -= hdr.size;
}
EXPORT_SYMBOL(tsv_byte_array_read);
int add_deserialization_func(void *ctxt, int type,
void (*dfunc)(struct encode_context *,
struct decode_context *))
{
struct ipc_log_context *ilctxt = (struct ipc_log_context *)ctxt;
struct dfunc_info *df_info;
unsigned long flags;
if (!ilctxt || !dfunc)
return -EINVAL;
df_info = kmalloc(sizeof(struct dfunc_info), GFP_KERNEL);
if (!df_info)
return -ENOSPC;
read_lock_irqsave(&context_list_lock_lha1, flags);
spin_lock(&ilctxt->context_lock_lhb1);
df_info->type = type;
df_info->dfunc = dfunc;
list_add_tail(&df_info->list, &ilctxt->dfunc_info_list);
spin_unlock(&ilctxt->context_lock_lhb1);
read_unlock_irqrestore(&context_list_lock_lha1, flags);
return 0;
}
EXPORT_SYMBOL(add_deserialization_func);
static void *get_deserialization_func(struct ipc_log_context *ilctxt,
int type)
{
struct dfunc_info *df_info = NULL;
if (!ilctxt)
return NULL;
list_for_each_entry(df_info, &ilctxt->dfunc_info_list, list) {
if (df_info->type == type)
return df_info->dfunc;
}
return NULL;
}
/**
* ipc_log_context_create: Create a debug log context if context does not exist.
* Should not be called from atomic context
*
* @max_num_pages: Number of pages of logging space required (max. 10)
* @mod_name : Name of the directory entry under DEBUGFS
* @user_version : Version number of user-defined message formats
*
* returns context id on success, NULL on failure
*/
void *ipc_log_context_create(int max_num_pages,
const char *mod_name, uint16_t user_version)
{
struct ipc_log_context *ctxt = NULL, *tmp;
struct ipc_log_page *pg = NULL;
int page_cnt;
unsigned long flags;
/* check if ipc ctxt already exists */
read_lock_irq(&context_list_lock_lha1);
list_for_each_entry(tmp, &ipc_log_context_list, list)
if (!strcmp(tmp->name, mod_name)) {
ctxt = tmp;
break;
}
read_unlock_irq(&context_list_lock_lha1);
if (ctxt)
return ctxt;
ctxt = kzalloc(sizeof(struct ipc_log_context), GFP_KERNEL);
if (!ctxt)
return 0;
init_completion(&ctxt->read_avail);
INIT_LIST_HEAD(&ctxt->page_list);
INIT_LIST_HEAD(&ctxt->dfunc_info_list);
spin_lock_init(&ctxt->context_lock_lhb1);
for (page_cnt = 0; page_cnt < max_num_pages; page_cnt++) {
pg = kzalloc(sizeof(struct ipc_log_page), GFP_KERNEL);
if (!pg)
goto release_ipc_log_context;
pg->hdr.log_id = (uint64_t)(uintptr_t)ctxt;
pg->hdr.page_num = LOG_PAGE_FLAG | page_cnt;
pg->hdr.ctx_offset = (int64_t)((uint64_t)(uintptr_t)ctxt -
(uint64_t)(uintptr_t)&pg->hdr);
/* set magic last to signal that page init is complete */
pg->hdr.magic = IPC_LOGGING_MAGIC_NUM;
pg->hdr.nmagic = ~(IPC_LOGGING_MAGIC_NUM);
spin_lock_irqsave(&ctxt->context_lock_lhb1, flags);
list_add_tail(&pg->hdr.list, &ctxt->page_list);
spin_unlock_irqrestore(&ctxt->context_lock_lhb1, flags);
}
ctxt->log_id = (uint64_t)(uintptr_t)ctxt;
ctxt->version = IPC_LOG_VERSION;
strlcpy(ctxt->name, mod_name, IPC_LOG_MAX_CONTEXT_NAME_LEN);
ctxt->user_version = user_version;
ctxt->first_page = get_first_page(ctxt);
ctxt->last_page = pg;
ctxt->write_page = ctxt->first_page;
ctxt->read_page = ctxt->first_page;
ctxt->nd_read_page = ctxt->first_page;
ctxt->write_avail = max_num_pages * LOG_PAGE_DATA_SIZE;
ctxt->header_size = sizeof(struct ipc_log_page_header);
kref_init(&ctxt->refcount);
ctxt->destroyed = false;
create_ctx_debugfs(ctxt, mod_name);
/* set magic last to signal context init is complete */
ctxt->magic = IPC_LOG_CONTEXT_MAGIC_NUM;
ctxt->nmagic = ~(IPC_LOG_CONTEXT_MAGIC_NUM);
write_lock_irqsave(&context_list_lock_lha1, flags);
list_add_tail(&ctxt->list, &ipc_log_context_list);
write_unlock_irqrestore(&context_list_lock_lha1, flags);
return (void *)ctxt;
release_ipc_log_context:
while (page_cnt-- > 0) {
pg = get_first_page(ctxt);
list_del(&pg->hdr.list);
kfree(pg);
}
kfree(ctxt);
return 0;
}
EXPORT_SYMBOL(ipc_log_context_create);
void ipc_log_context_free(struct kref *kref)
{
struct ipc_log_context *ilctxt = container_of(kref,
struct ipc_log_context, refcount);
struct ipc_log_page *pg = NULL;
while (!list_empty(&ilctxt->page_list)) {
pg = get_first_page(ilctxt);
list_del(&pg->hdr.list);
kfree(pg);
}
kfree(ilctxt);
}
/*
* Destroy debug log context
*
* @ctxt: debug log context created by calling ipc_log_context_create API.
*/
int ipc_log_context_destroy(void *ctxt)
{
struct ipc_log_context *ilctxt = (struct ipc_log_context *)ctxt;
struct dfunc_info *df_info = NULL, *tmp = NULL;
unsigned long flags;
if (!ilctxt)
return 0;
debugfs_remove_recursive(ilctxt->dent);
spin_lock(&ilctxt->context_lock_lhb1);
ilctxt->destroyed = true;
complete_all(&ilctxt->read_avail);
list_for_each_entry_safe(df_info, tmp, &ilctxt->dfunc_info_list, list) {
list_del(&df_info->list);
kfree(df_info);
}
spin_unlock(&ilctxt->context_lock_lhb1);
write_lock_irqsave(&context_list_lock_lha1, flags);
list_del(&ilctxt->list);
write_unlock_irqrestore(&context_list_lock_lha1, flags);
ipc_log_context_put(ilctxt);
return 0;
}
EXPORT_SYMBOL(ipc_log_context_destroy);
static int __init ipc_logging_init(void)
{
check_and_create_debugfs();
return 0;
}
module_init(ipc_logging_init);
MODULE_DESCRIPTION("ipc logging");
MODULE_LICENSE("GPL v2");

191
kernel/trace/ipc_logging_debug.c Normal file
View File

@@ -0,0 +1,191 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2012-2015, 2017-2019, The Linux Foundation. All rights reserved.
*/
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/jiffies.h>
#include <linux/debugfs.h>
#include <linux/io.h>
#include <linux/idr.h>
#include <linux/string.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/completion.h>
#include <linux/ipc_logging.h>
#include "ipc_logging_private.h"
static DEFINE_MUTEX(ipc_log_debugfs_init_lock);
static struct dentry *root_dent;
static int debug_log(struct ipc_log_context *ilctxt,
char *buff, int size, int cont)
{
int i = 0;
int ret;
if (size < MAX_MSG_DECODED_SIZE) {
pr_err("%s: buffer size %d < %d\n", __func__, size,
MAX_MSG_DECODED_SIZE);
return -ENOMEM;
}
do {
i = ipc_log_extract(ilctxt, buff, size - 1);
if (cont && i == 0) {
ret = wait_for_completion_interruptible(
&ilctxt->read_avail);
if (ret < 0)
return ret;
}
} while (cont && i == 0);
return i;
}
/*
* VFS Read operation helper which dispatches the call to the debugfs
* read command stored in file->private_data.
*
* @file File structure
* @buff user buffer
* @count size of user buffer
* @ppos file position to read from (only a value of 0 is accepted)
* @cont 1 = continuous mode (don't return 0 to signal end-of-file)
*
* @returns ==0 end of file
* >0 number of bytes read
* <0 error
*/
static ssize_t debug_read_helper(struct file *file, char __user *buff,
size_t count, loff_t *ppos, int cont)
{
struct ipc_log_context *ilctxt;
struct dentry *d = file->f_path.dentry;
char *buffer;
int bsize;
int r;
r = debugfs_file_get(d);
if (r)
return r;
ilctxt = file->private_data;
r = kref_get_unless_zero(&ilctxt->refcount) ? 0 : -EIO;
if (r) {
debugfs_file_put(d);
return r;
}
buffer = kmalloc(count, GFP_KERNEL);
if (!buffer) {
bsize = -ENOMEM;
goto done;
}
bsize = debug_log(ilctxt, buffer, count, cont);
if (bsize > 0) {
if (copy_to_user(buff, buffer, bsize)) {
bsize = -EFAULT;
kfree(buffer);
goto done;
}
*ppos += bsize;
}
kfree(buffer);
done:
ipc_log_context_put(ilctxt);
debugfs_file_put(d);
return bsize;
}
static ssize_t debug_read(struct file *file, char __user *buff,
size_t count, loff_t *ppos)
{
return debug_read_helper(file, buff, count, ppos, 0);
}
static ssize_t debug_read_cont(struct file *file, char __user *buff,
size_t count, loff_t *ppos)
{
return debug_read_helper(file, buff, count, ppos, 1);
}
static const struct file_operations debug_ops = {
.read = debug_read,
.open = simple_open,
};
static const struct file_operations debug_ops_cont = {
.read = debug_read_cont,
.open = simple_open,
};
static void debug_create(const char *name, mode_t mode,
struct dentry *dent,
struct ipc_log_context *ilctxt,
const struct file_operations *fops)
{
debugfs_create_file_unsafe(name, mode, dent, ilctxt, fops);
}
static void dfunc_string(struct encode_context *ectxt,
struct decode_context *dctxt)
{
tsv_timestamp_read(ectxt, dctxt, "");
tsv_qtimer_read(ectxt, dctxt, " ");
tsv_byte_array_read(ectxt, dctxt, "");
/* add trailing \n if necessary */
if (*(dctxt->buff - 1) != '\n') {
if (dctxt->size) {
++dctxt->buff;
--dctxt->size;
}
*(dctxt->buff - 1) = '\n';
}
}
void check_and_create_debugfs(void)
{
mutex_lock(&ipc_log_debugfs_init_lock);
if (!root_dent) {
root_dent = debugfs_create_dir("ipc_logging", 0);
if (IS_ERR(root_dent)) {
pr_err("%s: unable to create debugfs %ld\n",
__func__, PTR_ERR(root_dent));
root_dent = NULL;
}
}
mutex_unlock(&ipc_log_debugfs_init_lock);
}
EXPORT_SYMBOL(check_and_create_debugfs);
void create_ctx_debugfs(struct ipc_log_context *ctxt,
const char *mod_name)
{
if (!root_dent)
check_and_create_debugfs();
if (root_dent) {
ctxt->dent = debugfs_create_dir(mod_name, root_dent);
if (!IS_ERR(ctxt->dent)) {
debug_create("log", 0444, ctxt->dent,
ctxt, &debug_ops);
debug_create("log_cont", 0444, ctxt->dent,
ctxt, &debug_ops_cont);
}
}
add_deserialization_func((void *)ctxt,
TSV_TYPE_STRING, dfunc_string);
}
EXPORT_SYMBOL(create_ctx_debugfs);

166
kernel/trace/ipc_logging_private.h Normal file
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@@ -0,0 +1,166 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2012-2019, The Linux Foundation. All rights reserved.
*/
#ifndef _IPC_LOGGING_PRIVATE_H
#define _IPC_LOGGING_PRIVATE_H
#include <linux/ipc_logging.h>
#define IPC_LOG_VERSION 0x0003
#define IPC_LOG_MAX_CONTEXT_NAME_LEN 32
/**
* struct ipc_log_page_header - Individual log page header
*
* @magic: Magic number (used for log extraction)
* @nmagic: Inverse of magic number (used for log extraction)
* @page_num: Index of page (0.. N - 1) (note top bit is always set)
* @read_offset: Read offset in page
* @write_offset: Write offset in page (or 0xFFFF if full)
* @log_id: ID of logging context that owns this page
* @start_time: Scheduler clock for first write time in page
* @end_time: Scheduler clock for last write time in page
* @ctx_offset: Signed offset from page to the logging context. Used to
* optimize ram-dump extraction.
*
* @list: Linked list of pages that make up a log
* @nd_read_offset: Non-destructive read offset used for debugfs
*
* The first part of the structure defines data that is used to extract the
* logs from a memory dump and elements in this section should not be changed
* or re-ordered. New local data structures can be added to the end of the
* structure since they will be ignored by the extraction tool.
*/
struct ipc_log_page_header {
uint32_t magic;
uint32_t nmagic;
uint32_t page_num;
uint16_t read_offset;
uint16_t write_offset;
uint64_t log_id;
uint64_t start_time;
uint64_t end_time;
int64_t ctx_offset;
/* add local data structures after this point */
struct list_head list;
uint16_t nd_read_offset;
};
/**
* struct ipc_log_page - Individual log page
*
* @hdr: Log page header
* @data: Log data
*
* Each log consists of 1 to N log pages. Data size is adjusted to always fit
* the structure into a single kernel page.
*/
struct ipc_log_page {
struct ipc_log_page_header hdr;
char data[PAGE_SIZE - sizeof(struct ipc_log_page_header)];
};
/**
* struct ipc_log_context - main logging context
*
* @magic: Magic number (used for log extraction)
* @nmagic: Inverse of magic number (used for log extraction)
* @version: IPC Logging version of log format
* @user_version: Version number for user-defined messages
* @header_size: Size of the log header which is used to determine the offset
* of ipc_log_page::data
* @log_id: Log ID (assigned when log is created)
* @name: Name of the log used to uniquely identify the log during extraction
*
* @list: List of log contexts (struct ipc_log_context)
* @page_list: List of log pages (struct ipc_log_page)
* @first_page: First page in list of logging pages
* @last_page: Last page in list of logging pages
* @write_page: Current write page
* @read_page: Current read page (for internal reads)
* @nd_read_page: Current debugfs extraction page (non-destructive)
*
* @write_avail: Number of bytes available to write in all pages
* @dent: Debugfs node for run-time log extraction
* @dfunc_info_list: List of deserialization functions
* @context_lock_lhb1: Lock for entire structure
* @read_avail: Completed when new data is added to the log
*/
struct ipc_log_context {
uint32_t magic;
uint32_t nmagic;
uint32_t version;
uint16_t user_version;
uint16_t header_size;
uint64_t log_id;
char name[IPC_LOG_MAX_CONTEXT_NAME_LEN];
/* add local data structures after this point */
struct list_head list;
struct list_head page_list;
struct ipc_log_page *first_page;
struct ipc_log_page *last_page;
struct ipc_log_page *write_page;
struct ipc_log_page *read_page;
struct ipc_log_page *nd_read_page;
uint32_t write_avail;
struct dentry *dent;
struct list_head dfunc_info_list;
spinlock_t context_lock_lhb1;
struct completion read_avail;
struct kref refcount;
bool destroyed;
};
struct dfunc_info {
struct list_head list;
int type;
void (*dfunc)(struct encode_context *enc, struct decode_context *dec);
};
enum {
TSV_TYPE_INVALID,
TSV_TYPE_TIMESTAMP,
TSV_TYPE_POINTER,
TSV_TYPE_INT32,
TSV_TYPE_BYTE_ARRAY,
TSV_TYPE_QTIMER,
};
enum {
OUTPUT_DEBUGFS,
};
#define IPC_LOG_CONTEXT_MAGIC_NUM 0x25874452
#define IPC_LOGGING_MAGIC_NUM 0x52784425
#define MIN(x, y) ((x) < (y) ? (x) : (y))
#define IS_MSG_TYPE(x) (((x) > TSV_TYPE_MSG_START) && \
((x) < TSV_TYPE_MSG_END))
#define MAX_MSG_DECODED_SIZE (MAX_MSG_SIZE*4)
void ipc_log_context_free(struct kref *kref);
static inline void ipc_log_context_put(struct ipc_log_context *ilctxt)
{
kref_put(&ilctxt->refcount, ipc_log_context_free);
}
#if (defined(CONFIG_DEBUG_FS))
void check_and_create_debugfs(void);
void create_ctx_debugfs(struct ipc_log_context *ctxt,
const char *mod_name);
#else
void check_and_create_debugfs(void)
{
}
void create_ctx_debugfs(struct ipc_log_context *ctxt, const char *mod_name)
{
}
#endif
#endif