Commit ab400b0d authored by Anirudh Venkataramanan's avatar Anirudh Venkataramanan Committed by Tony Nguyen
Browse files

e1000e: Remove unnecessary use of kmap_atomic() 



alloc_rx_buf() allocates ps_page->page and buffer_info->page using either
GFP_ATOMIC or GFP_KERNEL. Memory allocated with GFP_KERNEL/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: default avatarIra Weiny <ira.weiny@intel.com>
Suggested-by: default avatarFabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: default avatarAnirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: default avatarNaama Meir <naamax.meir@linux.intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent 7bab8828

drivers/net/ethernet/intel/e1000e/netdev.c

+5 −15
Original line number Diff line number Diff line
@@ -1391,26 +1391,18 @@ static bool e1000_clean_rx_irq_ps(struct e1000_ring *rx_ring, int *work_done, 


			/* page alloc/put takes too long and effects small

			 * packet throughput, so unsplit small packets and

			 * save the alloc/put only valid in softirq (napi)

			 * context to call kmap_*

			 * save the alloc/put

			 */

			if (l1 && (l1 <= copybreak) &&

			    ((length + l1) <= adapter->rx_ps_bsize0)) {

				u8 *vaddr;



				ps_page = &buffer_info->ps_pages[0];



				/* there is no documentation about how to call

				 * kmap_atomic, so we can't hold the mapping

				 * very long

				 */

				dma_sync_single_for_cpu(&pdev->dev,

							ps_page->dma,

							PAGE_SIZE,

							DMA_FROM_DEVICE);

				vaddr = kmap_atomic(ps_page->page);

				memcpy(skb_tail_pointer(skb), vaddr, l1);

				kunmap_atomic(vaddr);

				memcpy(skb_tail_pointer(skb),

				       page_address(ps_page->page), l1);

				dma_sync_single_for_device(&pdev->dev,

							   ps_page->dma,

							   PAGE_SIZE,
@@ -1610,11 +1602,9 @@ static bool e1000_clean_jumbo_rx_irq(struct e1000_ring *rx_ring, int *work_done, 
				 */

				if (length <= copybreak &&

				    skb_tailroom(skb) >= length) {

					u8 *vaddr;

					vaddr = kmap_atomic(buffer_info->page);

					memcpy(skb_tail_pointer(skb), vaddr,

					memcpy(skb_tail_pointer(skb),

					       page_address(buffer_info->page),

					       length);

					kunmap_atomic(vaddr);

					/* re-use the page, so don't erase

					 * buffer_info->page

					 */