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	LITMUS^RT and MC^2 V1 support for the i.MX6 processor family.	Namhoon Kim

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Mode	Name	Size
d---------	802	344	logstatsplain
d---------	8021q	373	logstatsplain
d---------	9p	489	logstatsplain
-rw-r--r--	Kconfig	11190	logstatsplainblame
-rw-r--r--	Makefile	2025	logstatsplainblame
d---------	appletalk	222	logstatsplain
d---------	atm	1049	logstatsplain
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d---------	bridge	852	logstatsplain
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d---------	ceph	938	logstatsplain
-rw-r--r--	compat.c	25189	logstatsplainblame
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d---------	mac80211	2669	logstatsplain
d---------	mac802154	359	logstatsplain
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d---------	netlabel	668	logstatsplain
d---------	netlink	115	logstatsplain
d---------	netrom	383	logstatsplain
d---------	nfc	339	logstatsplain
-rw-r--r--	nonet.c	552	logstatsplainblame
d---------	openvswitch	541	logstatsplain
d---------	packet	182	logstatsplain
d---------	phonet	367	logstatsplain
d---------	rds	1702	logstatsplain
d---------	rfkill	263	logstatsplain
d---------	rose	432	logstatsplain
d---------	rxrpc	807	logstatsplain
d---------	sched	2214	logstatsplain
d---------	sctp	1123	logstatsplain
-rw-r--r--	socket.c	85466	logstatsplainblame
d---------	sunrpc	1139	logstatsplain
-rw-r--r--	sysctl_net.c	2499	logstatsplainblame
d---------	tipc	1395	logstatsplain
d---------	unix	224	logstatsplain
d---------	wanrouter	183	logstatsplain
d---------	wimax	422	logstatsplain
d---------	wireless	1410	logstatsplain
d---------	x25	538	logstatsplain
d---------	xfrm	551	logstatsplain

generated by cgit v1.2.2 (git 2.25.0) at 2025-04-15 01:40:38 -0400

/*
 * Copyright (C) 2008 Advanced Micro Devices, Inc.
 *
 * Author: Joerg Roedel <joerg.roedel@amd.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 */

#include <linux/scatterlist.h>
#include <linux/dma-mapping.h>
#include <linux/stacktrace.h>
#include <linux/dma-debug.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/export.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/ctype.h>
#include <linux/list.h>
#include <linux/slab.h>

#include <asm/sections.h>

#define HASH_SIZE       1024ULL
#define HASH_FN_SHIFT   13
#define HASH_FN_MASK    (HASH_SIZE - 1)

enum {
	dma_debug_single,
	dma_debug_page,
	dma_debug_sg,
	dma_debug_coherent,
};

#define DMA_DEBUG_STACKTRACE_ENTRIES 5

struct dma_debug_entry {
	struct list_head list;
	struct device    *dev;
	int              type;
	phys_addr_t      paddr;
	u64              dev_addr;
	u64              size;
	int              direction;
	int		 sg_call_ents;
	int		 sg_mapped_ents;
#ifdef CONFIG_STACKTRACE
	struct		 stack_trace stacktrace;
	unsigned long	 st_entries[DMA_DEBUG_STACKTRACE_ENTRIES];
#endif
};

typedef bool (*match_fn)(struct dma_debug_entry *, struct dma_debug_entry *);

struct hash_bucket {
	struct list_head list;
	spinlock_t lock;
} ____cacheline_aligned_in_smp;

/* Hash list to save the allocated dma addresses */
static struct hash_bucket dma_entry_hash[HASH_SIZE];
/* List of pre-allocated dma_debug_entry's */
static LIST_HEAD(free_entries);
/* Lock for the list above */
static DEFINE_SPINLOCK(free_entries_lock);

/* Global disable flag - will be set in case of an error */
static bool global_disable __read_mostly;

/* Global error count */
static u32 error_count;

/* Global error show enable*/
static u32 show_all_errors __read_mostly;
/* Number of errors to show */
static u32 show_num_errors = 1;

static u32 num_free_entries;
static u32 min_free_entries;
static u32 nr_total_entries;

/* number of preallocated entries requested by kernel cmdline */
static u32 req_entries;

/* debugfs dentry's for the stuff above */
static struct dentry *dma_debug_dent        __read_mostly;
static struct dentry *global_disable_dent   __read_mostly;
static struct dentry *error_count_dent      __read_mostly;
static struct dentry *show_all_errors_dent  __read_mostly;
static struct dentry *show_num_errors_dent  __read_mostly;
static struct dentry *num_free_entries_dent __read_mostly;
static struct dentry *min_free_entries_dent __read_mostly;
static struct dentry *filter_dent           __read_mostly;

/* per-driver filter related state */

#define NAME_MAX_LEN	64

static char                  current_driver_name[NAME_MAX_LEN] __read_mostly;
static struct device_driver *current_driver                    __read_mostly;

static DEFINE_RWLOCK(driver_name_lock);

static const char *type2name[4] = { "single", "page",
				    "scather-gather", "coherent" };

static const char *dir2name[4] = { "DMA_BIDIRECTIONAL", "DMA_TO_DEVICE",
				   "DMA_FROM_DEVICE", "DMA_NONE" };

/* little merge helper - remove it after the merge window */
#ifndef BUS_NOTIFY_UNBOUND_DRIVER
#define BUS_NOTIFY_UNBOUND_DRIVER 0x0005
#endif

/*
 * The access to some variables in this macro is racy. We can't use atomic_t
 * here because all these variables are exported to debugfs. Some of them even
 * writeable. This is also the reason why a lock won't help much. But anyway,
 * the races are no big deal. Here is why:
 *
 *   error_count: the addition is racy, but the worst thing that can happen is
 *                that we don't count some errors
 *   show_num_errors: the subtraction is racy. Also no big deal because in
 *                    worst case this will result in one warning more in the
 *                    system log than the user configured. This variable is
 *                    writeable via debugfs.
 */
static inline void dump_entry_trace(struct dma_debug_entry *entry)
{
#ifdef CONFIG_STACKTRACE
	if (entry) {
		pr_warning("Mapped at:\n");
		print_stack_trace(&entry->stacktrace, 0);
	}
#endif
}

static bool driver_filter(struct device *dev)
{
	struct device_driver *drv;
	unsigned long flags;
	bool ret;

	/* driver filter off */
	if (likely(!current_driver_name[0]))
		return true;

	/* driver filter on and initialized */
	if (current_driver && dev && dev->driver == current_driver)
		return true;

	/* driver filter on, but we can't filter on a NULL device... */
	if (!dev)
		return false;

	if (current_driver || !current_driver_name[0])
		return false;

	/* driver filter on but not yet initialized */
	drv = dev->driver;
	if (!drv)
		return false;

	/* lock to protect against change of current_driver_name */
	read_lock_irqsave(&driver_name_lock, flags);

	ret = false;
	if (drv->name &&
	    strncmp(current_driver_name, drv->name, NAME_MAX_LEN - 1) == 0) {
		current_driver = drv;
		ret = true;
	}

	read_unlock_irqrestore(&driver_name_lock, flags);

	return ret;
}

#define err_printk(dev, entry, format, arg...) do {			\
		error_count += 1;					\
		if (driver_filter(dev) &&				\
		    (show_all_errors || show_num_errors > 0)) {		\
			WARN(1, "%s %s: " format,			\
			     dev ? dev_driver_string(dev) : "NULL",	\
			     dev ? dev_name(dev) : "NULL", ## arg);	\
			dump_entry_trace(entry);			\
		}							\
		if (!show_all_errors && show_num_errors > 0)		\
			show_num_errors -= 1;				\
	} while (0);

/*
 * Hash related functions
 *
 * Every DMA-API request is saved into a struct dma_debug_entry. To
 * have quick access to these structs they are stored into a hash.
 */
static int hash_fn(struct dma_debug_entry *entry)
{
	/*
	 * Hash function is based on the dma address.
	 * We use bits 20-27 here as the index into the hash
	 */
	return (entry->dev_addr >> HASH_FN_SHIFT) & HASH_FN_MASK;
}

/*
 * Request exclusive access to a hash bucket for a given dma_debug_entry.
 */
static struct hash_bucket *get_hash_bucket(struct dma_debug_entry *entry,
					   unsigned long *flags)
{
	int idx = hash_fn(entry);
	unsigned long __flags;

	spin_lock_irqsave(&dma_entry_hash[idx].lock, __flags);
	*flags = __flags;
	return &dma_entry_hash[idx];
}

/*
 * Give up exclusive access to the hash bucket
 */
static void put_hash_bucket(struct hash_bucket *bucket,
			    unsigned long *flags)
{
	unsigned long __flags = *flags;

	spin_unlock_irqrestore(&bucket->lock, __flags);
}

static bool exact_match(struct dma_debug_entry *a, struct dma_debug_entry *b)
{
	return ((a->dev_addr == b->dev_addr) &&
		(a->dev == b->dev)) ? true : false;
}

static bool containing_match(struct dma_debug_entry *a,
			     struct dma_debug_entry *b)
{
	if (a->dev != b->dev)
		return false;

	if ((b->dev_addr <= a->dev_addr) &&
	    ((b->dev_addr + b->size) >= (a->dev_addr + a->size)))
		return true;

	return false;
}

/*
 * Search a given entry in the hash bucket list
 */
static struct dma_debug_entry *__hash_bucket_find(struct hash_bucket *bucket,
						  struct dma_debug_entry *ref,
						  match_fn match)
{
	struct dma_debug_entry *entry, *ret = NULL;
	int matches = 0, match_lvl, last_lvl = 0;

	list_for_each_entry(entry, &bucket->list, list) {
		if (!match(ref, entry))
			continue;

		/*
		 * Some drivers map the same physical address multiple
		 * times. Without a hardware IOMMU this results in the
		 * same device addresses being put into the dma-debug
		 * hash multiple times too. This can result in false
		 * positives being reported. Therefore we implement a
		 * best-fit algorithm here which returns the entry from
		 * the hash which fits best to the reference value
		 * instead of the first-fit.
		 */
		matches += 1;
		match_lvl = 0;
		entry->size         == ref->size         ? ++match_lvl : 0;
		entry->type         == ref->type         ? ++match_lvl : 0;
		entry->direction    == ref->direction    ? ++match_lvl : 0;
		entry->sg_call_ents == ref->sg_call_ents ? ++match_lvl : 0;

		if (match_lvl == 4) {
			/* perfect-fit - return the result */
			return entry;
		} else if (match_lvl > last_lvl) {
			/*
			 * We found an entry that fits better then the
			 * previous one
			 */
			last_lvl = match_lvl;
			ret      = entry;
		}
	}

	/*
	 * If we have multiple matches but no perfect-fit, just return
	 * NULL.
	 */
	ret = (matches == 1) ? ret : NULL;

	return ret;
}

static struct dma_debug_entry *bucket_find_exact(struct hash_bucket *bucket,
						 struct dma_debug_entry *ref)
{
	return __hash_bucket_find(bucket, ref, exact_match);
}

static struct dma_debug_entry *bucket_find_contain(struct hash_bucket **bucket,
						   struct dma_debug_entry *ref,
						   unsigned long *flags)
{

	unsigned int max_range = dma_get_max_seg_size(ref->dev);
	struct dma_debug_entry *entry, index = *ref;
	unsigned int range = 0;

	while (range <= max_range) {
		entry = __hash_bucket_find(*bucket, &index, containing_match);

		if (entry)
			return entry;

		/*
		 * Nothing found, go back a hash bucket
		 */
		put_hash_bucket(*bucket, flags);
		range          += (1 << HASH_FN_SHIFT);
		index.dev_addr -= (1 << HASH_FN_SHIFT);
		*bucket = get_hash_bucket(&index, flags);
	}

	return NULL;
}

/*
 * Add an entry to a hash bucket
 */
static void hash_bucket_add(struct hash_bucket *bucket,
			    struct dma_debug_entry *entry)
{
	list_add_tail(&entry->list, &bucket->list);
}

/*
 * Remove entry from a hash bucket list
 */
static void hash_bucket_del(struct dma_debug_entry *entry)
{
	list_del(&entry->list);
}

/*
 * Dump mapping entries for debugging purposes
 */
void debug_dma_dump_mappings(struct device *dev)
{
	int idx;

	for (idx = 0; idx < HASH_SIZE; idx++) {
		struct hash_bucket *bucket = &dma_entry_hash[idx];
		struct dma_debug_entry *entry;
		unsigned long flags;

		spin_lock_irqsave(&bucket->lock, flags);

		list_for_each_entry(entry, &bucket->list, list) {
			if (!dev || dev == entry->dev) {
				dev_info(entry->dev,
					 "%s idx %d P=%Lx D=%Lx L=%Lx %s\n",
					 type2name[entry->type], idx,
					 (unsigned long long)entry->paddr,
					 entry->dev_addr, entry->size,
					 dir2name[entry->direction]);
			}
		}

		spin_unlock_irqrestore(&bucket->lock, flags);
	}
}
EXPORT_SYMBOL(debug_dma_dump_mappings);

/*
 * Wrapper function for adding an entry to the hash.
 * This function takes care of locking itself.
 */
static void add_dma_entry(struct dma_debug_entry *entry)
{
	struct hash_bucket *bucket;
	unsigned long flags;

	bucket = get_hash_bucket(entry, &flags);
	hash_bucket_add(bucket, entry);
	put_hash_bucket(bucket, &flags);
}

static struct dma_debug_entry *__dma_entry_alloc(void)
{
	struct dma_debug_entry *entry;

	entry = list_entry(free_entries.next, struct dma_debug_entry, list);
	list_del(&entry->list);
	memset(entry, 0, sizeof(*entry));

	num_free_entries -= 1;
	if (num_free_entries < min_free_entries)
		min_free_entries = num_free_entries;

	return entry;
}

/* struct dma_entry allocator
 *
 * The next two functions implement the allocator for
 * struct dma_debug_entries.
 */
static struct dma_debug_entry *dma_entry_alloc(void)
{
	struct dma_debug_entry *entry = NULL;
	unsigned long flags;

	spin_lock_irqsave(&free_entries_lock, flags);

	if (list_empty(&free_entries)) {
		pr_err("DMA-API: debugging out of memory - disabling\n");
		global_disable = true;
		goto out;
	}

	entry = __dma_entry_alloc();

#ifdef CONFIG_STACKTRACE
	entry->stacktrace.max_entries = DMA_DEBUG_STACKTRACE_ENTRIES;
	entry->stacktrace.entries = entry->st_entries;
	entry->stacktrace.skip = 2;
	save_stack_trace(&entry->stacktrace);
#endif

out:
	spin_unlock_irqrestore(&free_entries_lock, flags);

	return entry;
}

static void dma_entry_free(struct dma_debug_entry *entry)
{
	unsigned long flags;

	/*
	 * add to beginning of the list - this way the entries are
	 * more likely cache hot when they are reallocated.
	 */
	spin_lock_irqsave(&free_entries_lock, flags);
	list_add(&entry->list, &free_entries);
	num_free_entries += 1;
	spin_unlock_irqrestore(&free_entries_lock, flags);
}

int dma_debug_resize_entries(u32 num_entries)
{
	int i, delta, ret = 0;
	unsigned long flags;
	struct dma_debug_entry *entry;
	LIST_HEAD(tmp);

	spin_lock_irqsave(&free_entries_lock, flags);

	if (nr_total_entries < num_entries) {
		delta = num_entries - nr_total_entries;

		spin_unlock_irqrestore(&free_entries_lock, flags);

		for (i = 0; i < delta; i++) {
			entry = kzalloc(sizeof(*entry), GFP_KERNEL);
			if (!entry)
				break;

			list_add_tail(&entry->list, &tmp);
		}

		spin_lock_irqsave(&free_entries_lock, flags);

		list_splice(&tmp, &free_entries);
		nr_total_entries += i;
		num_free_entries += i;
	} else {
		delta = nr_total_entries - num_entries;

		for (i = 0; i < delta && !list_empty(&free_entries); i++) {
			entry = __dma_entry_alloc();
			kfree(entry);
		}

		nr_total_entries -= i;
	}

	if (nr_total_entries != num_entries)
		ret = 1;

	spin_unlock_irqrestore(&free_entries_lock, flags);

	return ret;
}
EXPORT_SYMBOL(dma_debug_resize_entries);

/*
 * DMA-API debugging init code
 *
 * The init code does two things:
 *   1. Initialize core data structures
 *   2. Preallocate a given number of dma_debug_entry structs
 */

static int prealloc_memory(u32 num_entries)
{
	struct dma_debug_entry *entry, *next_entry;
	int i;

	for (i = 0; i < num_entries; ++i) {
		entry = kzalloc(sizeof(*entry), GFP_KERNEL);
		if (!entry)
			goto out_err;

		list_add_tail(&entry->list, &free_entries);
	}

	num_free_entries = num_entries;
	min_free_entries = num_entries;

	pr_info("DMA-API: preallocated %d debug entries\n", num_entries);

	return 0;

out_err:

	list_for_each_entry_safe(entry, next_entry, &free_entries, list) {
		list_del(&entry->list);
		kfree(entry);
	}

	return -ENOMEM;
}

static ssize_t filter_read(struct file *file, char __user *user_buf,
			   size_t count, loff_t *ppos)
{
	char buf[NAME_MAX_LEN + 1];
	unsigned long flags;
	int len;

	if (!current_driver_name[0])
		return 0;