[PATCH 08/20] dpaa_eth: use page backed rx buffers

From: Madalin Bucur
Date: Tue Oct 08 2019 - 08:12:34 EST


Change the buffers used for reception from netdev_frags to pages.

Signed-off-by: Madalin Bucur <madalin.bucur@xxxxxxx>
---
drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 51 +++++++++++---------------
1 file changed, 22 insertions(+), 29 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
index 7bfe437b0a50..ee267918aa70 100644
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
@@ -180,13 +180,7 @@ static struct dpaa_bp *dpaa_bp_array[BM_MAX_NUM_OF_POOLS];

#define DPAA_BP_RAW_SIZE 4096

-/* FMan-DMA requires 16-byte alignment for Rx buffers, but SKB_DATA_ALIGN is
- * even stronger (SMP_CACHE_BYTES-aligned), so we just get away with that,
- * via SKB_WITH_OVERHEAD(). We can't rely on netdev_alloc_frag() giving us
- * half-page-aligned buffers, so we reserve some more space for start-of-buffer
- * alignment.
- */
-#define dpaa_bp_size(raw_size) SKB_WITH_OVERHEAD((raw_size) - SMP_CACHE_BYTES)
+#define dpaa_bp_size(raw_size) SKB_WITH_OVERHEAD(raw_size)

static int dpaa_max_frm;

@@ -1313,13 +1307,14 @@ static void dpaa_fd_release(const struct net_device *net_dev,
vaddr = phys_to_virt(qm_fd_addr(fd));
sgt = vaddr + qm_fd_get_offset(fd);

- dma_unmap_single(dpaa_bp->priv->rx_dma_dev, qm_fd_addr(fd),
- dpaa_bp->size, DMA_FROM_DEVICE);
+ dma_unmap_page(dpaa_bp->priv->rx_dma_dev, qm_fd_addr(fd),
+ DPAA_BP_RAW_SIZE, DMA_FROM_DEVICE);

dpaa_release_sgt_members(sgt);

- addr = dma_map_single(dpaa_bp->priv->rx_dma_dev, vaddr,
- dpaa_bp->size, DMA_FROM_DEVICE);
+ addr = dma_map_page(dpaa_bp->priv->rx_dma_dev,
+ virt_to_page(vaddr), 0, DPAA_BP_RAW_SIZE,
+ DMA_FROM_DEVICE);
if (dma_mapping_error(dpaa_bp->priv->rx_dma_dev, addr)) {
netdev_err(net_dev, "DMA mapping failed");
return;
@@ -1469,21 +1464,18 @@ static int dpaa_bp_add_8_bufs(const struct dpaa_bp *dpaa_bp)
struct net_device *net_dev = dpaa_bp->priv->net_dev;
struct bm_buffer bmb[8];
dma_addr_t addr;
- void *new_buf;
+ struct page *p;
u8 i;

for (i = 0; i < 8; i++) {
- new_buf = netdev_alloc_frag(dpaa_bp->raw_size);
- if (unlikely(!new_buf)) {
- netdev_err(net_dev,
- "netdev_alloc_frag() failed, size %zu\n",
- dpaa_bp->raw_size);
+ p = dev_alloc_pages(0);
+ if (unlikely(!p)) {
+ netdev_err(net_dev, "dev_alloc_pages() failed\n");
goto release_previous_buffs;
}
- new_buf = PTR_ALIGN(new_buf, SMP_CACHE_BYTES);

- addr = dma_map_single(dpaa_bp->priv->rx_dma_dev, new_buf,
- dpaa_bp->size, DMA_FROM_DEVICE);
+ addr = dma_map_page(dpaa_bp->priv->rx_dma_dev, p, 0,
+ DPAA_BP_RAW_SIZE, DMA_FROM_DEVICE);
if (unlikely(dma_mapping_error(dpaa_bp->priv->rx_dma_dev,
addr))) {
netdev_err(net_dev, "DMA map failed");
@@ -1694,7 +1686,7 @@ static struct sk_buff *contig_fd_to_skb(const struct dpaa_priv *priv,
return skb;

free_buffer:
- skb_free_frag(vaddr);
+ free_pages((unsigned long)vaddr, 0);
return NULL;
}

@@ -1741,8 +1733,8 @@ static struct sk_buff *sg_fd_to_skb(const struct dpaa_priv *priv,
goto free_buffers;

count_ptr = this_cpu_ptr(dpaa_bp->percpu_count);
- dma_unmap_single(dpaa_bp->priv->rx_dma_dev, sg_addr,
- dpaa_bp->size, DMA_FROM_DEVICE);
+ dma_unmap_page(dpaa_bp->priv->rx_dma_dev, sg_addr,
+ DPAA_BP_RAW_SIZE, DMA_FROM_DEVICE);
if (!skb) {
sz = dpaa_bp->size +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
@@ -1794,7 +1786,7 @@ static struct sk_buff *sg_fd_to_skb(const struct dpaa_priv *priv,
WARN_ONCE(i == DPAA_SGT_MAX_ENTRIES, "No final bit on SGT\n");

/* free the SG table buffer */
- skb_free_frag(vaddr);
+ free_pages((unsigned long)vaddr, 0);

return skb;

@@ -1811,7 +1803,7 @@ static struct sk_buff *sg_fd_to_skb(const struct dpaa_priv *priv,
for (i = 0; i < DPAA_SGT_MAX_ENTRIES ; i++) {
sg_addr = qm_sg_addr(&sgt[i]);
sg_vaddr = phys_to_virt(sg_addr);
- skb_free_frag(sg_vaddr);
+ free_pages((unsigned long)sg_vaddr, 0);
dpaa_bp = dpaa_bpid2pool(sgt[i].bpid);
if (dpaa_bp) {
count_ptr = this_cpu_ptr(dpaa_bp->percpu_count);
@@ -1822,7 +1814,7 @@ static struct sk_buff *sg_fd_to_skb(const struct dpaa_priv *priv,
break;
}
/* free the SGT fragment */
- skb_free_frag(vaddr);
+ free_pages((unsigned long)vaddr, 0);

return NULL;
}
@@ -2281,8 +2273,8 @@ static enum qman_cb_dqrr_result rx_default_dqrr(struct qman_portal *portal,
return qman_cb_dqrr_consume;
}

- dma_unmap_single(dpaa_bp->priv->rx_dma_dev, addr, dpaa_bp->size,
- DMA_FROM_DEVICE);
+ dma_unmap_page(dpaa_bp->priv->rx_dma_dev, addr, DPAA_BP_RAW_SIZE,
+ DMA_FROM_DEVICE);

/* prefetch the first 64 bytes of the frame or the SGT start */
vaddr = phys_to_virt(addr);
@@ -2637,7 +2629,8 @@ static inline void dpaa_bp_free_pf(const struct dpaa_bp *bp,
{
dma_addr_t addr = bm_buf_addr(bmb);

- dma_unmap_single(bp->priv->rx_dma_dev, addr, bp->size, DMA_FROM_DEVICE);
+ dma_unmap_page(bp->priv->rx_dma_dev, addr, DPAA_BP_RAW_SIZE,
+ DMA_FROM_DEVICE);

skb_free_frag(phys_to_virt(addr));
}
--
2.1.0