linux-kernel - [PATCHv4 09/12] dmapool: simplify freeing

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Message-ID: <20230126215125.4069751-10-kbusch@meta.com>
Date:   Thu, 26 Jan 2023 13:51:22 -0800
From:   Keith Busch <kbusch@...a.com>
To:     <linux-mm@...ck.org>, <linux-kernel@...r.kernel.org>,
        <willy@...radead.org>, <hch@....de>, <tonyb@...ernetics.com>,
        <akpm@...ux-foundation.org>
CC:     <kernel-team@...a.com>, Keith Busch <kbusch@...nel.org>
Subject: [PATCHv4 09/12] dmapool: simplify freeing

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

The actions for busy and not busy are mostly the same, so combine these
and remove the unnecessary function. Also, the pool is about to be freed
so there's no need to poison the page data since we only check for
poison on alloc, which can't be done on a freed pool.

Signed-off-by: Keith Busch <kbusch@...nel.org>
Reviewed-by: Christoph Hellwig <hch@....de>
---
 mm/dmapool.c | 22 ++++++----------------
 1 file changed, 6 insertions(+), 16 deletions(-)

diff --git a/mm/dmapool.c b/mm/dmapool.c
index 9e98065a68b1f..4dea2a0dbd336 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -312,16 +312,6 @@ static inline bool is_page_busy(struct dma_page *page)
 	return page->in_use != 0;
 }
 
-static void pool_free_page(struct dma_pool *pool, struct dma_page *page)
-{
-	dma_addr_t dma = page->dma;
-
-	pool_init_page(pool, page);
-	dma_free_coherent(pool->dev, pool->allocation, page->vaddr, dma);
-	list_del(&page->page_list);
-	kfree(page);
-}
-
 /**
  * dma_pool_destroy - destroys a pool of dma memory blocks.
  * @pool: dma pool that will be destroyed
@@ -349,14 +339,14 @@ void dma_pool_destroy(struct dma_pool *pool)
 	mutex_unlock(&pools_reg_lock);
 
 	list_for_each_entry_safe(page, tmp, &pool->page_list, page_list) {
-		if (is_page_busy(page)) {
+		if (!is_page_busy(page))
+			dma_free_coherent(pool->dev, pool->allocation,
+					  page->vaddr, page->dma);
+		else
 			dev_err(pool->dev, "%s %s, %p busy\n", __func__,
 				pool->name, page->vaddr);
-			/* leak the still-in-use consistent memory */
-			list_del(&page->page_list);
-			kfree(page);
-		} else
-			pool_free_page(pool, page);
+		list_del(&page->page_list);
+		kfree(page);
 	}
 
 	kfree(pool);
-- 
2.30.2