ice: fix truesize operations for PAGE_SIZE >= 8192

[ Upstream commit d53d4dcce6 ]

When working on multi-buffer packet on arch that has PAGE_SIZE >= 8192,
truesize is calculated and stored in xdp_buff::frame_sz per each
processed Rx buffer. This means that frame_sz will contain the truesize
based on last received buffer, but commit 1dc1a7e7f4 ("ice:
Centrallize Rx buffer recycling") assumed this value will be constant
for each buffer, which breaks the page recycling scheme and mess up the
way we update the page::page_offset.

To fix this, let us work on constant truesize when PAGE_SIZE >= 8192
instead of basing this on size of a packet read from Rx descriptor. This
way we can simplify the code and avoid calculating truesize per each
received frame and on top of that when using
xdp_update_skb_shared_info(), current formula for truesize update will
be valid.

This means ice_rx_frame_truesize() can be removed altogether.
Furthermore, first call to it within ice_clean_rx_irq() for 4k PAGE_SIZE
was redundant as xdp_buff::frame_sz is initialized via xdp_init_buff()
in ice_vsi_cfg_rxq(). This should have been removed at the point where
xdp_buff struct started to be a member of ice_rx_ring and it was no
longer a stack based variable.

There are two fixes tags as my understanding is that the first one
exposed us to broken truesize and page_offset handling and then second
introduced broken skb_shared_info update in ice_{construct,build}_skb().

Reported-and-tested-by: Luiz Capitulino <luizcap@redhat.com>
Closes: https://lore.kernel.org/netdev/8f9e2a5c-fd30-4206-9311-946a06d031bb@redhat.com/
Fixes: 1dc1a7e7f4 ("ice: Centrallize Rx buffer recycling")
Fixes: 2fba7dc515 ("ice: Add support for XDP multi-buffer on Rx side")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Maciej Fijalkowski 2024-08-07 12:53:26 +02:00 committed by Greg Kroah-Hartman
parent e9a1df12d5
commit c864bf0166
2 changed files with 20 additions and 34 deletions

View File

@ -519,6 +519,25 @@ static int ice_setup_rx_ctx(struct ice_rx_ring *ring)
return 0;
}
/**
* ice_get_frame_sz - calculate xdp_buff::frame_sz
* @rx_ring: the ring being configured
*
* Return frame size based on underlying PAGE_SIZE
*/
static unsigned int ice_get_frame_sz(struct ice_rx_ring *rx_ring)
{
unsigned int frame_sz;
#if (PAGE_SIZE >= 8192)
frame_sz = rx_ring->rx_buf_len;
#else
frame_sz = ice_rx_pg_size(rx_ring) / 2;
#endif
return frame_sz;
}
/**
* ice_vsi_cfg_rxq - Configure an Rx queue
* @ring: the ring being configured
@ -582,7 +601,7 @@ int ice_vsi_cfg_rxq(struct ice_rx_ring *ring)
}
}
xdp_init_buff(&ring->xdp, ice_rx_pg_size(ring) / 2, &ring->xdp_rxq);
xdp_init_buff(&ring->xdp, ice_get_frame_sz(ring), &ring->xdp_rxq);
ring->xdp.data = NULL;
err = ice_setup_rx_ctx(ring);
if (err) {

View File

@ -521,30 +521,6 @@ err:
return -ENOMEM;
}
/**
* ice_rx_frame_truesize
* @rx_ring: ptr to Rx ring
* @size: size
*
* calculate the truesize with taking into the account PAGE_SIZE of
* underlying arch
*/
static unsigned int
ice_rx_frame_truesize(struct ice_rx_ring *rx_ring, const unsigned int size)
{
unsigned int truesize;
#if (PAGE_SIZE < 8192)
truesize = ice_rx_pg_size(rx_ring) / 2; /* Must be power-of-2 */
#else
truesize = rx_ring->rx_offset ?
SKB_DATA_ALIGN(rx_ring->rx_offset + size) +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)) :
SKB_DATA_ALIGN(size);
#endif
return truesize;
}
/**
* ice_run_xdp - Executes an XDP program on initialized xdp_buff
* @rx_ring: Rx ring
@ -1152,11 +1128,6 @@ int ice_clean_rx_irq(struct ice_rx_ring *rx_ring, int budget)
bool failure;
u32 first;
/* Frame size depend on rx_ring setup when PAGE_SIZE=4K */
#if (PAGE_SIZE < 8192)
xdp->frame_sz = ice_rx_frame_truesize(rx_ring, 0);
#endif
xdp_prog = READ_ONCE(rx_ring->xdp_prog);
if (xdp_prog) {
xdp_ring = rx_ring->xdp_ring;
@ -1216,10 +1187,6 @@ int ice_clean_rx_irq(struct ice_rx_ring *rx_ring, int budget)
hard_start = page_address(rx_buf->page) + rx_buf->page_offset -
offset;
xdp_prepare_buff(xdp, hard_start, offset, size, !!offset);
#if (PAGE_SIZE > 4096)
/* At larger PAGE_SIZE, frame_sz depend on len size */
xdp->frame_sz = ice_rx_frame_truesize(rx_ring, size);
#endif
xdp_buff_clear_frags_flag(xdp);
} else if (ice_add_xdp_frag(rx_ring, xdp, rx_buf, size)) {
break;