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: Ira Weiny <ira.weiny@intel.com>
Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Naama Meir <naamax.meir@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index f0e015673f489dcbed1ae86558263af28f63824e..36bc4fd91ef4fa694338b76c6f812b7d585fc3b2 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -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
                                         */