ice: configure FW logging

Users want the ability to debug FW issues by retrieving the
FW logs from the E8xx devices. Use debugfs to allow the user to
configure the log level and number of messages for FW logging.

If FW logging is supported on the E8xx then the file 'fwlog' will be
created under the PCI device ID for the ice driver. If the file does not
exist then either the E8xx doesn't support FW logging or debugfs is not
enabled on the system.

One thing users want to do is control which events are reported. The
user can read and write the 'fwlog/modules/<module name>' to get/set
the log levels. Each module in the FW that supports logging ht as a file
under 'fwlog/modules' that supports reading (to see what the current log
level is) and writing (to change the log level).

The format to set the log levels for a module are:

  # echo <log level> > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/<module>

The supported log levels are:

      *	none
      *	error
      *	warning
      *	normal
      *	verbose

Each level includes the messages from the previous/lower level

The modules that are supported are:

      *	general
      *	ctrl
      *	link
      *	link_topo
      *	dnl
      *	i2c
      *	sdp
      *	mdio
      *	adminq
      *	hdma
      *	lldp
      *	dcbx
      *	dcb
      *	xlr
      *	nvm
      *	auth
      *	vpd
      *	iosf
      *	parser
      *	sw
      *	scheduler
      *	txq
      *	rsvd
      *	post
      *	watchdog
      *	task_dispatch
      *	mng
      *	synce
      *	health
      *	tsdrv
      *	pfreg
      *	mdlver
      *	all

The module 'all' is a special module which allows the user to read or
write to all of the modules.

The following example command would set the DCB module to the 'normal'
log level:

  # echo normal > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/dcb

If the user wants to set the DCB, Link, and the AdminQ modules to
'verbose' then the commands are:

  # echo verbose > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/dcb
  # echo verbose > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/link
  # echo verbose > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/adminq

If the user wants to set all modules to the 'warning' level then the
command is:

  # echo warning > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/all

If the user wants to disable logging for a module then they can set the
level to 'none'. An example setting the 'watchdog' module is:

  # echo none > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/watchdog

If the user wants to see what the log level is for a specific module
then the command is:

  # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/dcb

This will return the log level for the DCB module. If the user wants to
see the log level for all the modules then the command is:

  # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/modules/all

Writing to the module file will update the configuration, but NOT enable the
configuration (that is a separate command).

In addition to configuring the modules, the user can also configure the
number of log messages (nr_messages) to include in a single Admin Receive
Queue (ARQ) event.The range is 1-128 (1 means push every log message, 128
means push only when the max AQ command buffer is full). The suggested
value is 10.

To see/change the resolution the user can read/write the
'fwlog/nr_messages' file. An example changing the value to 50 is

  # echo 50 > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/nr_messages

To see the current value of 'nr_messages' then the command is:

  # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/nr_messages

Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 359 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_debugfs.c b/drivers/net/ethernet/intel/ice/ice_debugfs.c
new file mode 100644
index 000000000000..3b0d9b214fd1
--- /dev/null
+++ b/drivers/net/ethernet/intel/ice/ice_debugfs.c
@@ -0,0 +1,359 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022, Intel Corporation. */
+
+#include <linux/fs.h>
+#include <linux/debugfs.h>
+#include <linux/random.h>
+#include <linux/vmalloc.h>
+#include "ice.h"
+
+static struct dentry *ice_debugfs_root;
+
+/* create a define that has an extra module that doesn't really exist. this
+ * is so we can add a module 'all' to easily enable/disable all the modules
+ */
+#define ICE_NR_FW_LOG_MODULES (ICE_AQC_FW_LOG_ID_MAX + 1)
+
+/* the ordering in this array is important. it matches the ordering of the
+ * values in the FW so the index is the same value as in ice_aqc_fw_logging_mod
+ */
+static const char * const ice_fwlog_module_string[] = {
+	"general",
+	"ctrl",
+	"link",
+	"link_topo",
+	"dnl",
+	"i2c",
+	"sdp",
+	"mdio",
+	"adminq",
+	"hdma",
+	"lldp",
+	"dcbx",
+	"dcb",
+	"xlr",
+	"nvm",
+	"auth",
+	"vpd",
+	"iosf",
+	"parser",
+	"sw",
+	"scheduler",
+	"txq",
+	"rsvd",
+	"post",
+	"watchdog",
+	"task_dispatch",
+	"mng",
+	"synce",
+	"health",
+	"tsdrv",
+	"pfreg",
+	"mdlver",
+	"all",
+};
+
+/* the ordering in this array is important. it matches the ordering of the
+ * values in the FW so the index is the same value as in ice_fwlog_level
+ */
+static const char * const ice_fwlog_level_string[] = {
+	"none",
+	"error",
+	"warning",
+	"normal",
+	"verbose",
+};
+
+/**
+ * ice_fwlog_print_module_cfg - print current FW logging module configuration
+ * @hw: pointer to the HW structure
+ * @module: module to print
+ * @s: the seq file to put data into
+ */
+static void
+ice_fwlog_print_module_cfg(struct ice_hw *hw, int module, struct seq_file *s)
+{
+	struct ice_fwlog_cfg *cfg = &hw->fwlog_cfg;
+	struct ice_fwlog_module_entry *entry;
+
+	if (module != ICE_AQC_FW_LOG_ID_MAX) {
+		entry =	&cfg->module_entries[module];
+
+		seq_printf(s, "\tModule: %s, Log Level: %s\n",
+			   ice_fwlog_module_string[entry->module_id],
+			   ice_fwlog_level_string[entry->log_level]);
+	} else {
+		int i;
+
+		for (i = 0; i < ICE_AQC_FW_LOG_ID_MAX; i++) {
+			entry =	&cfg->module_entries[i];
+
+			seq_printf(s, "\tModule: %s, Log Level: %s\n",
+				   ice_fwlog_module_string[entry->module_id],
+				   ice_fwlog_level_string[entry->log_level]);
+		}
+	}
+}
+
+static int ice_find_module_by_dentry(struct ice_pf *pf, struct dentry *d)
+{
+	int i, module;
+
+	module = -1;
+	/* find the module based on the dentry */
+	for (i = 0; i < ICE_NR_FW_LOG_MODULES; i++) {
+		if (d == pf->ice_debugfs_pf_fwlog_modules[i]) {
+			module = i;
+			break;
+		}
+	}
+
+	return module;
+}
+
+/**
+ * ice_debugfs_module_show - read from 'module' file
+ * @s: the opened file
+ * @v: pointer to the offset
+ */
+static int ice_debugfs_module_show(struct seq_file *s, void *v)
+{
+	const struct file *filp = s->file;
+	struct dentry *dentry;
+	struct ice_pf *pf;
+	int module;
+
+	dentry = file_dentry(filp);
+	pf = s->private;
+
+	module = ice_find_module_by_dentry(pf, dentry);
+	if (module < 0) {
+		dev_info(ice_pf_to_dev(pf), "unknown module\n");
+		return -EINVAL;
+	}
+
+	ice_fwlog_print_module_cfg(&pf->hw, module, s);
+
+	return 0;
+}
+
+static int ice_debugfs_module_open(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, ice_debugfs_module_show, inode->i_private);
+}
+
+/**
+ * ice_debugfs_module_write - write into 'module' file
+ * @filp: the opened file
+ * @buf: where to find the user's data
+ * @count: the length of the user's data
+ * @ppos: file position offset
+ */
+static ssize_t
+ice_debugfs_module_write(struct file *filp, const char __user *buf,
+			 size_t count, loff_t *ppos)
+{
+	struct ice_pf *pf = file_inode(filp)->i_private;
+	struct dentry *dentry = file_dentry(filp);
+	struct device *dev = ice_pf_to_dev(pf);
+	char user_val[16], *cmd_buf;
+	int module, log_level, cnt;
+
+	/* don't allow partial writes or invalid input */
+	if (*ppos != 0 || count > 8)
+		return -EINVAL;
+
+	cmd_buf = memdup_user(buf, count);
+	if (IS_ERR(cmd_buf))
+		return PTR_ERR(cmd_buf);
+
+	module = ice_find_module_by_dentry(pf, dentry);
+	if (module < 0) {
+		dev_info(dev, "unknown module\n");
+		return -EINVAL;
+	}
+
+	cnt = sscanf(cmd_buf, "%s", user_val);
+	if (cnt != 1)
+		return -EINVAL;
+
+	log_level = sysfs_match_string(ice_fwlog_level_string, user_val);
+	if (log_level < 0) {
+		dev_info(dev, "unknown log level '%s'\n", user_val);
+		return -EINVAL;
+	}
+
+	if (module != ICE_AQC_FW_LOG_ID_MAX) {
+		ice_pf_fwlog_update_module(pf, log_level, module);
+	} else {
+		/* the module 'all' is a shortcut so that we can set
+		 * all of the modules to the same level quickly
+		 */
+		int i;
+
+		for (i = 0; i < ICE_AQC_FW_LOG_ID_MAX; i++)
+			ice_pf_fwlog_update_module(pf, log_level, i);
+	}
+
+	return count;
+}
+
+static const struct file_operations ice_debugfs_module_fops = {
+	.owner = THIS_MODULE,
+	.open  = ice_debugfs_module_open,
+	.read = seq_read,
+	.release = single_release,
+	.write = ice_debugfs_module_write,
+};
+
+/**
+ * ice_debugfs_nr_messages_read - read from 'nr_messages' file
+ * @filp: the opened file
+ * @buffer: where to write the data for the user to read
+ * @count: the size of the user's buffer
+ * @ppos: file position offset
+ */
+static ssize_t ice_debugfs_nr_messages_read(struct file *filp,
+					    char __user *buffer, size_t count,
+					    loff_t *ppos)
+{
+	struct ice_pf *pf = filp->private_data;
+	struct ice_hw *hw = &pf->hw;
+	char buff[32] = {};
+
+	snprintf(buff, sizeof(buff), "%d\n",
+		 hw->fwlog_cfg.log_resolution);
+
+	return simple_read_from_buffer(buffer, count, ppos, buff, strlen(buff));
+}
+
+/**
+ * ice_debugfs_nr_messages_write - write into 'nr_messages' file
+ * @filp: the opened file
+ * @buf: where to find the user's data
+ * @count: the length of the user's data
+ * @ppos: file position offset
+ */
+static ssize_t
+ice_debugfs_nr_messages_write(struct file *filp, const char __user *buf,
+			      size_t count, loff_t *ppos)
+{
+	struct ice_pf *pf = filp->private_data;
+	struct device *dev = ice_pf_to_dev(pf);
+	struct ice_hw *hw = &pf->hw;
+	char user_val[8], *cmd_buf;
+	s16 nr_messages;
+	ssize_t ret;
+
+	/* don't allow partial writes or invalid input */
+	if (*ppos != 0 || count > 4)
+		return -EINVAL;
+
+	cmd_buf = memdup_user(buf, count);
+	if (IS_ERR(cmd_buf))
+		return PTR_ERR(cmd_buf);
+
+	ret = sscanf(cmd_buf, "%s", user_val);
+	if (ret != 1)
+		return -EINVAL;
+
+	ret = kstrtos16(user_val, 0, &nr_messages);
+	if (ret)
+		return ret;
+
+	if (nr_messages < ICE_AQC_FW_LOG_MIN_RESOLUTION ||
+	    nr_messages > ICE_AQC_FW_LOG_MAX_RESOLUTION) {
+		dev_err(dev, "Invalid FW log number of messages %d, value must be between %d - %d\n",
+			nr_messages, ICE_AQC_FW_LOG_MIN_RESOLUTION,
+			ICE_AQC_FW_LOG_MAX_RESOLUTION);
+		return -EINVAL;
+	}
+
+	hw->fwlog_cfg.log_resolution = nr_messages;
+
+	return count;
+}
+
+static const struct file_operations ice_debugfs_nr_messages_fops = {
+	.owner = THIS_MODULE,
+	.open  = simple_open,
+	.read = ice_debugfs_nr_messages_read,
+	.write = ice_debugfs_nr_messages_write,
+};
+
+/**
+ * ice_debugfs_fwlog_init - setup the debugfs directory
+ * @pf: the ice that is starting up
+ */
+void ice_debugfs_fwlog_init(struct ice_pf *pf)
+{
+	const char *name = pci_name(pf->pdev);
+	struct dentry *fw_modules_dir;
+	struct dentry **fw_modules;
+	int i;
+
+	/* only support fw log commands on PF 0 */
+	if (pf->hw.bus.func)
+		return;
+
+	/* allocate space for this first because if it fails then we don't
+	 * need to unwind
+	 */
+	fw_modules = kcalloc(ICE_NR_FW_LOG_MODULES, sizeof(*fw_modules),
+			     GFP_KERNEL);
+	if (!fw_modules)
+		return;
+
+	pf->ice_debugfs_pf = debugfs_create_dir(name, ice_debugfs_root);
+	if (IS_ERR(pf->ice_debugfs_pf))
+		goto err_create_module_files;
+
+	pf->ice_debugfs_pf_fwlog = debugfs_create_dir("fwlog",
+						      pf->ice_debugfs_pf);
+	if (IS_ERR(pf->ice_debugfs_pf))
+		goto err_create_module_files;
+
+	fw_modules_dir = debugfs_create_dir("modules",
+					    pf->ice_debugfs_pf_fwlog);
+	if (IS_ERR(fw_modules_dir))
+		goto err_create_module_files;
+
+	for (i = 0; i < ICE_NR_FW_LOG_MODULES; i++) {
+		fw_modules[i] = debugfs_create_file(ice_fwlog_module_string[i],
+						    0600, fw_modules_dir, pf,
+						    &ice_debugfs_module_fops);
+		if (IS_ERR(fw_modules[i]))
+			goto err_create_module_files;
+	}
+
+	debugfs_create_file("nr_messages", 0600,
+			    pf->ice_debugfs_pf_fwlog, pf,
+			    &ice_debugfs_nr_messages_fops);
+
+	pf->ice_debugfs_pf_fwlog_modules = fw_modules;
+
+	return;
+
+err_create_module_files:
+	debugfs_remove_recursive(pf->ice_debugfs_pf_fwlog);
+	kfree(fw_modules);
+}
+
+/**
+ * ice_debugfs_init - create root directory for debugfs entries
+ */
+void ice_debugfs_init(void)
+{
+	ice_debugfs_root = debugfs_create_dir(KBUILD_MODNAME, NULL);
+	if (IS_ERR(ice_debugfs_root))
+		pr_info("init of debugfs failed\n");
+}
+
+/**
+ * ice_debugfs_exit - remove debugfs entries
+ */
+void ice_debugfs_exit(void)
+{
+	debugfs_remove_recursive(ice_debugfs_root);
+	ice_debugfs_root = NULL;
+}