include/linux/stackprotector.h


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#ifndef _LINUX_STACKPROTECTOR_H
#define _LINUX_STACKPROTECTOR_H 1

#include <linux/compiler.h>
#include <linux/sched.h>
#include <linux/random.h>

#ifdef CONFIG_CC_STACKPROTECTOR
# include <asm/stackprotector.h>
#else
static inline void boot_init_stack_canary(void)
{
}
#endif

#endif
/*
 * DMA Pool allocator
 *
 * Copyright 2001 David Brownell
 * Copyright 2007 Intel Corporation
 *   Author: Matthew Wilcox <willy@linux.intel.com>
 *
 * This software may be redistributed and/or modified under the terms of
 * the GNU General Public License ("GPL") version 2 as published by the
 * Free Software Foundation.
 *
 * This allocator returns small blocks of a given size which are DMA-able by
 * the given device.  It uses the dma_alloc_coherent page allocator to get
 * new pages, then splits them up into blocks of the required size.
 * Many older drivers still have their own code to do this.
 *
 * The current design of this allocator is fairly simple.  The pool is
 * represented by the 'struct dma_pool' which keeps a doubly-linked list of
 * allocated pages.  Each page in the page_list is split into blocks of at
 * least 'size' bytes.  Free blocks are tracked in an unsorted singly-linked
 * list of free blocks within the page.  Used blocks aren't tracked, but we
 * keep a count of how many are currently allocated from each page.
 */

#include <linux/device.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/poison.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/wait.h>

#if defined(CONFIG_DEBUG_SLAB) || defined(CONFIG_SLUB_DEBUG_ON)
#define DMAPOOL_DEBUG 1
#endif

struct dma_pool {		/* the pool */
	struct list_head page_list;
	spinlock_t lock;
	size_t size;
	struct device *dev;
	size_t allocation;
	size_t boundary;
	char name[32];
	wait_queue_head_t waitq;
	struct list_head pools;
};

struct dma_page {		/* cacheable header for 'allocation' bytes */
	struct list_head page_list;
	void *vaddr;
	dma_addr_t dma;
	unsigned int in_use;
	unsigned int offset;
};

#define	POOL_TIMEOUT_JIFFIES	((100 /* msec */ * HZ) / 1000)

static DEFINE_MUTEX(pools_lock);

static ssize_t
show_pools(struct device *dev, struct device_attribute *attr, char *buf)
{
	unsigned temp;
	unsigned size;
	char *next;
	struct dma_page *page;
	struct dma_pool *pool;

	next = buf;
	size = PAGE_SIZE;

	temp = scnprintf(next, size, "poolinfo - 0.1\n");
	size -= temp;
	next += temp;

	mutex_lock(&pools_lock);
	list_for_each_entry(pool, &dev->dma_pools, pools) {
		unsigned pages = 0;
		unsigned blocks = 0;

		spin_lock_irq(&pool->lock);
		list_for_each_entry(page, &pool->page_list, page_list) {
			pages++;
			blocks += page->in_use;
		}
		spin_unlock_irq(&pool->lock);

		/* per-pool info, no real statistics yet */
		temp = scnprintf(next, size, "%-16s %4u %4Zu %4Zu %2u\n",
				 pool->name, blocks,
				 pages * (pool->allocation / pool->size),
				 pool->size, pages);
		size -= temp;
		next += temp;
	}
	mutex_unlock(&pools_lock);

	return PAGE_SIZE - size;
}

static DEVICE_ATTR(pools, S_IRUGO, show_pools, NULL);

/**
 * dma_pool_create - Creates a pool of consistent memory blocks, for dma.
 * @name: name of pool, for diagnostics
 * @dev: device that will be doing the DMA
 * @size: size of the blocks in this pool.
 * @align: alignment requirement for blocks; must be a power of two
 * @boundary: returned blocks won't cross this power of two boundary
 * Context: !in_interrupt()
 *
 * Returns a dma allocation pool with the requested characteristics, or
 * null if one can't be created.  Given one of these pools, dma_pool_alloc()
 * may be used to allocate memory.  Such memory will all have "consistent"
 * DMA mappings, accessible by the device and its driver without using
 * cache flushing primitives.  The actual size of blocks allocated may be
 * larger than requested because of alignment.
 *
 * If @boundary is nonzero, objects returned from dma_pool_alloc() won't
 * cross that size boundary.  This is useful for devices which have
 * addressing restrictions on individual DMA transfers, such as not crossing
 * boundaries of 4KBytes.
 */
struct dma_pool *dma_pool_create(const char *name, struct device *dev,
				 size_t size, size_t align, size_t boundary)
{
	struct dma_pool *retval;
	size_t allocation;

	if (align == 0) {
		align = 1;
	} else if (align & (align - 1)) {
		return NULL;
	}

	if (size == 0) {
		return NULL;
	} else if (size < 4) {
		size = 4;
	}

	if ((size % align) != 0)
		size = ALIGN(size, align);

	allocation = max_t(size_t, size, PAGE_SIZE);

	if (!boundary) {
		boundary = allocation;
	} else if ((boundary < size) || (boundary & (boundary - 1))) {
		return NULL;
	}

	retval = kmalloc_node(sizeof(*retval), GFP_KERNEL, dev_to_node(dev));
	if (!retval)
		return retval;