diff options
Diffstat (limited to 'kernel/trace/ipc_logging.c')
| -rw-r--r-- | kernel/trace/ipc_logging.c | 876 |
1 files changed, 876 insertions, 0 deletions
diff --git a/kernel/trace/ipc_logging.c b/kernel/trace/ipc_logging.c new file mode 100644 index 000000000000..ed29c38cd7fb --- /dev/null +++ b/kernel/trace/ipc_logging.c @@ -0,0 +1,876 @@ +/* Copyright (c) 2012-2017, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#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/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); + BUG_ON(ilctxt->nd_read_page == NULL); + + 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); + BUG_ON(ilctxt->read_page == NULL); + ilctxt->nd_read_page = ilctxt->read_page; + } else { + ilctxt->read_page = get_next_page(ilctxt, + ilctxt->read_page); + BUG_ON(ilctxt->read_page == NULL); + } + + 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); + BUG_ON(ilctxt->write_page == NULL); + 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); + BUG_ON(ectxt->hdr.size > MAX_MSG_SIZE); + memcpy(ectxt->buff, &ectxt->hdr, sizeof(ectxt->hdr)); +} +EXPORT_SYMBOL(msg_encode_end); + +/* + * Helper funtion 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; + + 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); + 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); + } + if ((size - dctxt.size) == 0) + reinit_completion(&ilctxt->read_avail); + spin_unlock(&ilctxt->context_lock_lhb1); + read_unlock_irqrestore(&context_list_lock_lha1, flags); + return size - dctxt.size; +} +EXPORT_SYMBOL(ipc_log_extract); + +/* + * Helper funtion 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) +{ + BUG_ON((ectxt->offset + size) > MAX_MSG_SIZE); + 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) +{ + BUG_ON((ectxt->offset + sizeof(*hdr)) > MAX_MSG_SIZE); + 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); + BUG_ON(hdr.type != TSV_TYPE_TIMESTAMP); + tsv_read_data(ectxt, &val, sizeof(val)); + nanosec_rem = do_div(val, 1000000000U); + IPC_SPRINTF_DECODE(dctxt, "[%6u.%09lu%s/", + (unsigned)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); + BUG_ON(hdr.type != TSV_TYPE_QTIMER); + 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); + BUG_ON(hdr.type != TSV_TYPE_POINTER); + 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); + BUG_ON(hdr.type != TSV_TYPE_INT32); + 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); + BUG_ON(hdr.type != TSV_TYPE_BYTE_ARRAY); + 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 + * 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; + struct ipc_log_page *pg = NULL; + int page_cnt; + unsigned long flags; + + ctxt = kzalloc(sizeof(struct ipc_log_context), GFP_KERNEL); + if (!ctxt) { + pr_err("%s: cannot create ipc_log_context\n", __func__); + 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) { + pr_err("%s: cannot create ipc_log_page\n", __func__); + 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); + 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); + +/* + * 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 ipc_log_page *pg = NULL; + unsigned long flags; + + if (!ilctxt) + return 0; + + while (!list_empty(&ilctxt->page_list)) { + pg = get_first_page(ctxt); + list_del(&pg->hdr.list); + kfree(pg); + } + + write_lock_irqsave(&context_list_lock_lha1, flags); + list_del(&ilctxt->list); + write_unlock_irqrestore(&context_list_lock_lha1, flags); + + debugfs_remove_recursive(ilctxt->dent); + + kfree(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"); 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