Commit 52e7d565 authored by Keith Busch's avatar Keith Busch Committed by Andrew Morton
Browse files

dmapool: move debug code to own functions 

Clean up the normal path by moving the debug code outside it.

Link: https://lkml.kernel.org/r/20230126215125.4069751-7-kbusch@meta.com


Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 19f50458

mm/dmapool.c

+77 −51
Original line number Diff line number Diff line
@@ -96,6 +96,78 @@ static ssize_t pools_show(struct device *dev, struct device_attribute *attr, cha 


static DEVICE_ATTR_RO(pools);



#ifdef DMAPOOL_DEBUG

static void pool_check_block(struct dma_pool *pool, void *retval,

			     unsigned int offset, gfp_t mem_flags)

{

	int i;

	u8 *data = retval;

	/* page->offset is stored in first 4 bytes */

	for (i = sizeof(offset); i < pool->size; i++) {

		if (data[i] == POOL_POISON_FREED)

			continue;

		dev_err(pool->dev, "%s %s, %p (corrupted)\n",

			__func__, pool->name, retval);



		/*

		 * Dump the first 4 bytes even if they are not

		 * POOL_POISON_FREED

		 */

		print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,

				data, pool->size, 1);

		break;

	}

	if (!want_init_on_alloc(mem_flags))

		memset(retval, POOL_POISON_ALLOCATED, pool->size);

}



static bool pool_page_err(struct dma_pool *pool, struct dma_page *page,

			  void *vaddr, dma_addr_t dma)

{

	unsigned int offset = vaddr - page->vaddr;

	unsigned int chain = page->offset;



	if ((dma - page->dma) != offset) {

		dev_err(pool->dev, "%s %s, %p (bad vaddr)/%pad\n",

			__func__, pool->name, vaddr, &dma);

		return true;

	}



	while (chain < pool->allocation) {

		if (chain != offset) {

			chain = *(int *)(page->vaddr + chain);

			continue;

		}

		dev_err(pool->dev, "%s %s, dma %pad already free\n",

			__func__, pool->name, &dma);

		return true;

	}

	memset(vaddr, POOL_POISON_FREED, pool->size);

	return false;

}



static void pool_init_page(struct dma_pool *pool, struct dma_page *page)

{

	memset(page->vaddr, POOL_POISON_FREED, pool->allocation);

}

#else

static void pool_check_block(struct dma_pool *pool, void *retval,

			     unsigned int offset, gfp_t mem_flags)



{

}



static bool pool_page_err(struct dma_pool *pool, struct dma_page *page,

			  void *vaddr, dma_addr_t dma)

{

	return false;

}



static void pool_init_page(struct dma_pool *pool, struct dma_page *page)

{

}

#endif



/**

 * dma_pool_create - Creates a pool of consistent memory blocks, for dma.

 * @name: name of pool, for diagnostics
@@ -223,9 +295,7 @@ static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags) 
	page->vaddr = dma_alloc_coherent(pool->dev, pool->allocation,

					 &page->dma, mem_flags);

	if (page->vaddr) {

#ifdef	DMAPOOL_DEBUG

		memset(page->vaddr, POOL_POISON_FREED, pool->allocation);

#endif

		pool_init_page(pool, page);

		pool_initialise_page(pool, page);

		page->in_use = 0;

		page->offset = 0;
@@ -245,9 +315,7 @@ static void pool_free_page(struct dma_pool *pool, struct dma_page *page) 
{

	dma_addr_t dma = page->dma;



#ifdef	DMAPOOL_DEBUG

	memset(page->vaddr, POOL_POISON_FREED, pool->allocation);

#endif

	pool_init_page(pool, page);

	dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma);

	list_del(&page->page_list);

	kfree(page);
@@ -336,29 +404,7 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags, 
	page->offset = *(int *)(page->vaddr + offset);

	retval = offset + page->vaddr;

	*handle = offset + page->dma;

#ifdef	DMAPOOL_DEBUG

	{

		int i;

		u8 *data = retval;

		/* page->offset is stored in first 4 bytes */

		for (i = sizeof(page->offset); i < pool->size; i++) {

			if (data[i] == POOL_POISON_FREED)

				continue;

			dev_err(pool->dev, "%s %s, %p (corrupted)\n",

				__func__, pool->name, retval);



			/*

			 * Dump the first 4 bytes even if they are not

			 * POOL_POISON_FREED

			 */

			print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,

					data, pool->size, 1);

			break;

		}

	}

	if (!want_init_on_alloc(mem_flags))

		memset(retval, POOL_POISON_ALLOCATED, pool->size);

#endif

	pool_check_block(pool, retval, offset, mem_flags);

	spin_unlock_irqrestore(&pool->lock, flags);



	if (want_init_on_alloc(mem_flags))
@@ -394,7 +440,6 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma) 
{

	struct dma_page *page;

	unsigned long flags;

	unsigned int offset;



	spin_lock_irqsave(&pool->lock, flags);

	page = pool_find_page(pool, dma);
@@ -405,35 +450,16 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma) 
		return;

	}



	offset = vaddr - page->vaddr;

	if (want_init_on_free())

		memset(vaddr, 0, pool->size);

#ifdef	DMAPOOL_DEBUG

	if ((dma - page->dma) != offset) {

	if (pool_page_err(pool, page, vaddr, dma)) {

		spin_unlock_irqrestore(&pool->lock, flags);

		dev_err(pool->dev, "%s %s, %p (bad vaddr)/%pad\n",

			__func__, pool->name, vaddr, &dma);

		return;

	}

	{

		unsigned int chain = page->offset;

		while (chain < pool->allocation) {

			if (chain != offset) {

				chain = *(int *)(page->vaddr + chain);

				continue;

			}

			spin_unlock_irqrestore(&pool->lock, flags);

			dev_err(pool->dev, "%s %s, dma %pad already free\n",

				__func__, pool->name, &dma);

			return;

		}

	}

	memset(vaddr, POOL_POISON_FREED, pool->size);

#endif



	page->in_use--;

	*(int *)vaddr = page->offset;

	page->offset = offset;

	page->offset = vaddr - page->vaddr;

	/*

	 * Resist a temptation to do

	 *    if (!is_page_busy(page)) pool_free_page(pool, page);