diff options
author | Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> | 2022-11-23 23:52:16 +0300 |
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committer | David S. Miller <davem@davemloft.net> | 2022-11-25 13:44:01 +0300 |
commit | c191445874bba16a636a88fc4afc7c3ab09228fd (patch) | |
tree | 5f5cc756b7aff6261a8d2dbaf9f065c913da9ce4 /drivers/net | |
parent | f61e6d3ca4dac83d7093e7be7ceabce95e738e68 (diff) | |
download | linux-c191445874bba16a636a88fc4afc7c3ab09228fd.tar.xz |
cassini: Use page_address() instead of kmap_atomic()
Pages for Rx buffers are allocated in cas_page_alloc() 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() instead. This makes the variable 'addr' unnecessary, so
remove it too.
Note that kmap_atomic() disables preemption and page-fault processing,
but page_address() doesn't. When removing uses of kmap_atomic(), one has to
check if the code being executed between the map/unmap implicitly depends
on page-faults and/or preemption being disabled. If yes, then code to
disable page-faults and/or preemption should also be added for functional
correctness. That however doesn't appear to be the case here, so just
page_address() is used.
I don't have hardware, so this change has only been compile tested.
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
-rw-r--r-- | drivers/net/ethernet/sun/cassini.c | 34 |
1 files changed, 11 insertions, 23 deletions
diff --git a/drivers/net/ethernet/sun/cassini.c b/drivers/net/ethernet/sun/cassini.c index 0aca193d9550..2f66cfc5e796 100644 --- a/drivers/net/ethernet/sun/cassini.c +++ b/drivers/net/ethernet/sun/cassini.c @@ -1915,7 +1915,7 @@ static int cas_rx_process_pkt(struct cas *cp, struct cas_rx_comp *rxc, int off, swivel = RX_SWIVEL_OFF_VAL; struct cas_page *page; struct sk_buff *skb; - void *addr, *crcaddr; + void *crcaddr; __sum16 csum; char *p; @@ -1936,7 +1936,7 @@ static int cas_rx_process_pkt(struct cas *cp, struct cas_rx_comp *rxc, skb_reserve(skb, swivel); p = skb->data; - addr = crcaddr = NULL; + crcaddr = NULL; if (hlen) { /* always copy header pages */ i = CAS_VAL(RX_COMP2_HDR_INDEX, words[1]); page = cp->rx_pages[CAS_VAL(RX_INDEX_RING, i)][CAS_VAL(RX_INDEX_NUM, i)]; @@ -1948,12 +1948,10 @@ static int cas_rx_process_pkt(struct cas *cp, struct cas_rx_comp *rxc, i += cp->crc_size; dma_sync_single_for_cpu(&cp->pdev->dev, page->dma_addr + off, i, DMA_FROM_DEVICE); - addr = cas_page_map(page->buffer); - memcpy(p, addr + off, i); + memcpy(p, page_address(page->buffer) + off, i); dma_sync_single_for_device(&cp->pdev->dev, page->dma_addr + off, i, DMA_FROM_DEVICE); - cas_page_unmap(addr); RX_USED_ADD(page, 0x100); p += hlen; swivel = 0; @@ -1984,12 +1982,11 @@ static int cas_rx_process_pkt(struct cas *cp, struct cas_rx_comp *rxc, /* make sure we always copy a header */ swivel = 0; if (p == (char *) skb->data) { /* not split */ - addr = cas_page_map(page->buffer); - memcpy(p, addr + off, RX_COPY_MIN); + memcpy(p, page_address(page->buffer) + off, + RX_COPY_MIN); dma_sync_single_for_device(&cp->pdev->dev, page->dma_addr + off, i, DMA_FROM_DEVICE); - cas_page_unmap(addr); off += RX_COPY_MIN; swivel = RX_COPY_MIN; RX_USED_ADD(page, cp->mtu_stride); @@ -2036,10 +2033,8 @@ static int cas_rx_process_pkt(struct cas *cp, struct cas_rx_comp *rxc, RX_USED_ADD(page, hlen + cp->crc_size); } - if (cp->crc_size) { - addr = cas_page_map(page->buffer); - crcaddr = addr + off + hlen; - } + if (cp->crc_size) + crcaddr = page_address(page->buffer) + off + hlen; } else { /* copying packet */ @@ -2061,12 +2056,10 @@ static int cas_rx_process_pkt(struct cas *cp, struct cas_rx_comp *rxc, i += cp->crc_size; dma_sync_single_for_cpu(&cp->pdev->dev, page->dma_addr + off, i, DMA_FROM_DEVICE); - addr = cas_page_map(page->buffer); - memcpy(p, addr + off, i); + memcpy(p, page_address(page->buffer) + off, i); dma_sync_single_for_device(&cp->pdev->dev, page->dma_addr + off, i, DMA_FROM_DEVICE); - cas_page_unmap(addr); if (p == (char *) skb->data) /* not split */ RX_USED_ADD(page, cp->mtu_stride); else @@ -2081,20 +2074,17 @@ static int cas_rx_process_pkt(struct cas *cp, struct cas_rx_comp *rxc, page->dma_addr, dlen + cp->crc_size, DMA_FROM_DEVICE); - addr = cas_page_map(page->buffer); - memcpy(p, addr, dlen + cp->crc_size); + memcpy(p, page_address(page->buffer), dlen + cp->crc_size); dma_sync_single_for_device(&cp->pdev->dev, page->dma_addr, dlen + cp->crc_size, DMA_FROM_DEVICE); - cas_page_unmap(addr); RX_USED_ADD(page, dlen + cp->crc_size); } end_copy_pkt: - if (cp->crc_size) { - addr = NULL; + if (cp->crc_size) crcaddr = skb->data + alloclen; - } + skb_put(skb, alloclen); } @@ -2103,8 +2093,6 @@ end_copy_pkt: /* checksum includes FCS. strip it out. */ csum = csum_fold(csum_partial(crcaddr, cp->crc_size, csum_unfold(csum))); - if (addr) - cas_page_unmap(addr); } skb->protocol = eth_type_trans(skb, cp->dev); if (skb->protocol == htons(ETH_P_IP)) { |