From: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Date: Mon, 19 Sep 2022 18:09:48 +0000 (-0700)
Subject: e1000: Remove unnecessary use of kmap_atomic()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3e7b52e0eb9ef7e67c26072cb1c7a49a5cc356f5;p=linux.git

e1000: Remove unnecessary use of kmap_atomic()

buffer_info->rxbuf.page accessed in e1000_clean_jumbo_rx_irq() is
allocated using GFP_ATOMIC. Pages allocated with GFP_ATOMIC can't come from
highmem and so there's no need to kmap() them. Just use page_address().

I don't have access to a 32-bit system so did some limited testing on
qemu (qemu-system-i386 -m 4096 -smp 4 -device e1000e) with a 32-bit
Debian 11.04 image.

Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>
Cc: Tony Nguyen <anthony.l.nguyen@intel.com>
Suggested-by: Ira Weiny <ira.weiny@intel.com>
Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---

diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c
index 61e60e4de600f..da6e303ad99b5 100644
--- a/drivers/net/ethernet/intel/e1000/e1000_main.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_main.c
@@ -4229,8 +4229,6 @@ process_skb:
 				 */
 				p = buffer_info->rxbuf.page;
 				if (length <= copybreak) {
-					u8 *vaddr;
-
 					if (likely(!(netdev->features & NETIF_F_RXFCS)))
 						length -= 4;
 					skb = e1000_alloc_rx_skb(adapter,
@@ -4238,10 +4236,9 @@ process_skb:
 					if (!skb)
 						break;
 
-					vaddr = kmap_atomic(p);
-					memcpy(skb_tail_pointer(skb), vaddr,
-					       length);
-					kunmap_atomic(vaddr);
+					memcpy(skb_tail_pointer(skb),
+					       page_address(p), length);
+
 					/* re-use the page, so don't erase
 					 * buffer_info->rxbuf.page
 					 */