linux-kernel - [PATCH 06/11] dmapool: move debug code to own functions

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Message-ID: <20221205145937.54367-7-kbusch@meta.com>
Date:   Mon, 5 Dec 2022 06:59:32 -0800
From:   Keith Busch <kbusch@...a.com>
To:     <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        Matthew Wilcox <willy@...radead.org>
CC:     Tony Battersby <tonyb@...ernetics.com>,
        Keith Busch <kbusch@...nel.org>
Subject: [PATCH 06/11] dmapool: move debug code to own functions

From: Keith Busch <kbusch@...nel.org>

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

Signed-off-by: Keith Busch <kbusch@...nel.org>
---
 mm/dmapool.c | 96 +++++++++++++++++++++++++++++-----------------------
 1 file changed, 54 insertions(+), 42 deletions(-)

diff --git a/mm/dmapool.c b/mm/dmapool.c
index eaed3ffb42aa8..8a7aa19e650a1 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -294,6 +294,32 @@ void dma_pool_destroy(struct dma_pool *pool)
 }
 EXPORT_SYMBOL(dma_pool_destroy);
 
+static inline void pool_check_block(struct dma_pool *pool, void *retval,
+				    unsigned int offset, gfp_t mem_flags)
+{
+#ifdef	DMAPOOL_DEBUG
+	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);
+#endif
+}
+
 /**
  * dma_pool_alloc - get a block of consistent memory
  * @pool: dma pool that will produce the block
@@ -336,29 +362,7 @@ 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))
@@ -381,6 +385,32 @@ static struct dma_page *pool_find_page(struct dma_pool *pool, dma_addr_t dma)
 	return NULL;
 }
 
+static inline bool pool_page_err(struct dma_pool *pool, struct dma_page *page,
+				 void *vaddr)
+{
+#ifdef DMAPOOL_DEBUG
+	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);
+#endif
+	return false;
+}
+
 /**
  * dma_pool_free - put block back into dma pool
  * @pool: the dma pool holding the block
@@ -408,28 +438,10 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
 	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)) {
 		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;
-- 
2.30.2