log: Add an implementation of logging
Add the logging header file and implementation with some configuration
options to control it.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/log.c b/common/log.c
new file mode 100644
index 0000000..8f36c79
--- /dev/null
+++ b/common/log.c
@@ -0,0 +1,244 @@
+/*
+ * Logging support
+ *
+ * Copyright (c) 2017 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <common.h>
+#include <log.h>
+#include <malloc.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static struct log_device *log_device_find_by_name(const char *drv_name)
+{
+ struct log_device *ldev;
+
+ list_for_each_entry(ldev, &gd->log_head, sibling_node) {
+ if (!strcmp(drv_name, ldev->drv->name))
+ return ldev;
+ }
+
+ return NULL;
+}
+
+/**
+ * log_has_cat() - check if a log category exists within a list
+ *
+ * @cat_list: List of categories to check, at most LOGF_MAX_CATEGORIES entries
+ * long, terminated by LC_END if fewer
+ * @cat: Category to search for
+ * @return true if @cat is in @cat_list, else false
+ */
+static bool log_has_cat(enum log_category_t cat_list[], enum log_category_t cat)
+{
+ int i;
+
+ for (i = 0; i < LOGF_MAX_CATEGORIES && cat_list[i] != LOGC_END; i++) {
+ if (cat_list[i] == cat)
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * log_has_file() - check if a file is with a list
+ *
+ * @file_list: List of files to check, separated by comma
+ * @file: File to check for. This string is matched against the end of each
+ * file in the list, i.e. ignoring any preceding path. The list is
+ * intended to consist of relative pathnames, e.g. common/main.c,cmd/log.c
+ * @return true if @file is in @file_list, else false
+ */
+static bool log_has_file(const char *file_list, const char *file)
+{
+ int file_len = strlen(file);
+ const char *s, *p;
+ int substr_len;
+
+ for (s = file_list; *s; s = p + (*p != '\0')) {
+ p = strchrnul(s, ',');
+ substr_len = p - s;
+ if (file_len >= substr_len &&
+ !strncmp(file + file_len - substr_len, s, substr_len))
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * log_passes_filters() - check if a log record passes the filters for a device
+ *
+ * @ldev: Log device to check
+ * @rec: Log record to check
+ * @return true if @rec is not blocked by the filters in @ldev, false if it is
+ */
+static bool log_passes_filters(struct log_device *ldev, struct log_rec *rec)
+{
+ struct log_filter *filt;
+
+ /* If there are no filters, filter on the default log level */
+ if (list_empty(&ldev->filter_head)) {
+ if (rec->level > gd->default_log_level)
+ return false;
+ return true;
+ }
+
+ list_for_each_entry(filt, &ldev->filter_head, sibling_node) {
+ if (rec->level > filt->max_level)
+ continue;
+ if ((filt->flags & LOGFF_HAS_CAT) &&
+ !log_has_cat(filt->cat_list, rec->cat))
+ continue;
+ if (filt->file_list &&
+ !log_has_file(filt->file_list, rec->file))
+ continue;
+ return true;
+ }
+
+ return false;
+}
+
+/**
+ * log_dispatch() - Send a log record to all log devices for processing
+ *
+ * The log record is sent to each log device in turn, skipping those which have
+ * filters which block the record
+ *
+ * @rec: Log record to dispatch
+ * @return 0 (meaning success)
+ */
+static int log_dispatch(struct log_rec *rec)
+{
+ struct log_device *ldev;
+
+ list_for_each_entry(ldev, &gd->log_head, sibling_node) {
+ if (log_passes_filters(ldev, rec))
+ ldev->drv->emit(ldev, rec);
+ }
+
+ return 0;
+}
+
+int _log(enum log_category_t cat, enum log_level_t level, const char *file,
+ int line, const char *func, const char *fmt, ...)
+{
+ char buf[CONFIG_SYS_CBSIZE];
+ struct log_rec rec;
+ va_list args;
+
+ rec.cat = cat;
+ rec.level = level;
+ rec.file = file;
+ rec.line = line;
+ rec.func = func;
+ va_start(args, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, args);
+ va_end(args);
+ rec.msg = buf;
+ if (!gd || !(gd->flags & GD_FLG_LOG_READY)) {
+ if (gd)
+ gd->log_drop_count++;
+ return -ENOSYS;
+ }
+ log_dispatch(&rec);
+
+ return 0;
+}
+
+int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
+ enum log_level_t max_level, const char *file_list)
+{
+ struct log_filter *filt;
+ struct log_device *ldev;
+ int i;
+
+ ldev = log_device_find_by_name(drv_name);
+ if (!ldev)
+ return -ENOENT;
+ filt = (struct log_filter *)calloc(1, sizeof(*filt));
+ if (!filt)
+ return -ENOMEM;
+
+ if (cat_list) {
+ filt->flags |= LOGFF_HAS_CAT;
+ for (i = 0; ; i++) {
+ if (i == ARRAY_SIZE(filt->cat_list))
+ return -ENOSPC;
+ filt->cat_list[i] = cat_list[i];
+ if (cat_list[i] == LOGC_END)
+ break;
+ }
+ }
+ filt->max_level = max_level;
+ if (file_list) {
+ filt->file_list = strdup(file_list);
+ if (!filt->file_list)
+ goto nomem;
+ }
+ filt->filter_num = ldev->next_filter_num++;
+ list_add_tail(&filt->sibling_node, &ldev->filter_head);
+
+ return filt->filter_num;
+
+nomem:
+ free(filt);
+ return -ENOMEM;
+}
+
+int log_remove_filter(const char *drv_name, int filter_num)
+{
+ struct log_filter *filt;
+ struct log_device *ldev;
+
+ ldev = log_device_find_by_name(drv_name);
+ if (!ldev)
+ return -ENOENT;
+
+ list_for_each_entry(filt, &ldev->filter_head, sibling_node) {
+ if (filt->filter_num == filter_num) {
+ list_del(&filt->sibling_node);
+ free(filt);
+
+ return 0;
+ }
+ }
+
+ return -ENOENT;
+}
+
+int log_init(void)
+{
+ struct log_driver *drv = ll_entry_start(struct log_driver, log_driver);
+ const int count = ll_entry_count(struct log_driver, log_driver);
+ struct log_driver *end = drv + count;
+
+ /*
+ * We cannot add runtime data to the driver since it is likely stored
+ * in rodata. Instead, set up a 'device' corresponding to each driver.
+ * We only support having a single device.
+ */
+ INIT_LIST_HEAD((struct list_head *)&gd->log_head);
+ while (drv < end) {
+ struct log_device *ldev;
+
+ ldev = calloc(1, sizeof(*ldev));
+ if (!ldev) {
+ debug("%s: Cannot allocate memory\n", __func__);
+ return -ENOMEM;
+ }
+ INIT_LIST_HEAD(&ldev->filter_head);
+ ldev->drv = drv;
+ list_add_tail(&ldev->sibling_node,
+ (struct list_head *)&gd->log_head);
+ drv++;
+ }
+ gd->default_log_level = LOGL_INFO;
+
+ return 0;
+}