[PATCH bpf-next v3 05/11] ixgbe: modify driver for handling offsets

[Kevin Laatz <kevin.laatz@xxxxxxxxx>]

With the addition of the unaligned chunks option, we need to make sure we
handle the offsets accordingly based on the mode we are currently running
in. This patch modifies the driver to appropriately mask the address for
each case.

Signed-off-by: Kevin Laatz <kevin.laatz@xxxxxxxxx>

---
v3:
  - Use new helper function to handle offset
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
index bc86057628c8..4481916563a8 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_xsk.c
@@ -143,7 +143,9 @@ static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
 			    struct ixgbe_ring *rx_ring,
 			    struct xdp_buff *xdp)
 {
+	struct xdp_umem *umem = rx_ring->xsk_umem;
 	int err, result = IXGBE_XDP_PASS;
+	u64 offset = umem->headroom;
 	struct bpf_prog *xdp_prog;
 	struct xdp_frame *xdpf;
 	u32 act;
@@ -151,7 +153,10 @@ static int ixgbe_run_xdp_zc(struct ixgbe_adapter *adapter,
 	rcu_read_lock();
 	xdp_prog = READ_ONCE(rx_ring->xdp_prog);
 	act = bpf_prog_run_xdp(xdp_prog, xdp);
-	xdp->handle += xdp->data - xdp->data_hard_start;
+	offset += xdp->data - xdp->data_hard_start;
+
+	xdp->handle = xsk_umem_handle_offset(umem, xdp->handle, offset);
+
 	switch (act) {
 	case XDP_PASS:
 		break;
@@ -243,7 +248,7 @@ void ixgbe_zca_free(struct zero_copy_allocator *alloc, unsigned long handle)
 	bi->addr = xdp_umem_get_data(rx_ring->xsk_umem, handle);
 	bi->addr += hr;
 
-	bi->handle = (u64)handle + rx_ring->xsk_umem->headroom;
+	bi->handle = (u64)handle;
 }
 
 static bool ixgbe_alloc_buffer_zc(struct ixgbe_ring *rx_ring,
@@ -269,7 +274,7 @@ static bool ixgbe_alloc_buffer_zc(struct ixgbe_ring *rx_ring,
 	bi->addr = xdp_umem_get_data(umem, handle);
 	bi->addr += hr;
 
-	bi->handle = handle + umem->headroom;
+	bi->handle = handle;
 
 	xsk_umem_discard_addr(umem);
 	return true;
@@ -296,7 +301,7 @@ static bool ixgbe_alloc_buffer_slow_zc(struct ixgbe_ring *rx_ring,
 	bi->addr = xdp_umem_get_data(umem, handle);
 	bi->addr += hr;
 
-	bi->handle = handle + umem->headroom;
+	bi->handle = handle;
 
 	xsk_umem_discard_addr_rq(umem);
 	return true;
@@ -565,6 +570,7 @@ static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
 	struct ixgbe_tx_buffer *tx_bi;
 	bool work_done = true;
 	struct xdp_desc desc;
+	u64 addr, offset;
 	dma_addr_t dma;
 	u32 cmd_type;
 
@@ -578,7 +584,11 @@ static bool ixgbe_xmit_zc(struct ixgbe_ring *xdp_ring, unsigned int budget)
 		if (!xsk_umem_consume_tx(xdp_ring->xsk_umem, &desc))
 			break;
 
-		dma = xdp_umem_get_dma(xdp_ring->xsk_umem, desc.addr);
+		/* for unaligned chunks need to take offset from upper bits */
+		offset = (desc.addr >> XSK_UNALIGNED_BUF_OFFSET_SHIFT);
+		addr = (desc.addr & XSK_UNALIGNED_BUF_ADDR_MASK);
+
+		dma = xdp_umem_get_dma(xdp_ring->xsk_umem, addr + offset);
 
 		dma_sync_single_for_device(xdp_ring->dev, dma, desc.len,
 					   DMA_BIDIRECTIONAL);
-- 
2.17.1