This is a note to let you know that I've just added the patch titled igc: read before write to SRRCTL register to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: igc-read-before-write-to-srrctl-register.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 3184abdc9131d206e062ce37d216468251ad2df6 Author: Song Yoong Siang <yoong.siang.song@xxxxxxxxx> Date: Tue May 2 08:48:06 2023 -0700 igc: read before write to SRRCTL register [ Upstream commit 3ce29c17dc847bf4245e16aad78a7617afa96297 ] igc_configure_rx_ring() function will be called as part of XDP program setup. If Rx hardware timestamp is enabled prio to XDP program setup, this timestamp enablement will be overwritten when buffer size is written into SRRCTL register. Thus, this commit read the register value before write to SRRCTL register. This commit is tested by using xdp_hw_metadata bpf selftest tool. The tool enables Rx hardware timestamp and then attach XDP program to igc driver. It will display hardware timestamp of UDP packet with port number 9092. Below are detail of test steps and results. Command on DUT: sudo ./xdp_hw_metadata <interface name> Command on Link Partner: echo -n skb | nc -u -q1 <destination IPv4 addr> 9092 Result before this patch: skb hwtstamp is not found! Result after this patch: found skb hwtstamp = 1677800973.642836757 Optionally, read PHC to confirm the values obtained are almost the same: Command: sudo ./testptp -d /dev/ptp0 -g Result: clock time: 1677800973.913598978 or Fri Mar 3 07:49:33 2023 Fixes: fc9df2a0b520 ("igc: Enable RX via AF_XDP zero-copy") Cc: <stable@xxxxxxxxxxxxxxx> # 5.14+ Signed-off-by: Song Yoong Siang <yoong.siang.song@xxxxxxxxx> Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx> Reviewed-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Tested-by: Jesper Dangaard Brouer <brouer@xxxxxxxxxx> Tested-by: Naama Meir <naamax.meir@xxxxxxxxxxxxxxx> Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx> Reviewed-by: Leon Romanovsky <leonro@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/intel/igc/igc_base.h b/drivers/net/ethernet/intel/igc/igc_base.h index ce530f5fd7bda..52849f5e8048d 100644 --- a/drivers/net/ethernet/intel/igc/igc_base.h +++ b/drivers/net/ethernet/intel/igc/igc_base.h @@ -85,8 +85,13 @@ union igc_adv_rx_desc { #define IGC_RXDCTL_SWFLUSH 0x04000000 /* Receive Software Flush */ /* SRRCTL bit definitions */ -#define IGC_SRRCTL_BSIZEPKT_SHIFT 10 /* Shift _right_ */ -#define IGC_SRRCTL_BSIZEHDRSIZE_SHIFT 2 /* Shift _left_ */ -#define IGC_SRRCTL_DESCTYPE_ADV_ONEBUF 0x02000000 +#define IGC_SRRCTL_BSIZEPKT_MASK GENMASK(6, 0) +#define IGC_SRRCTL_BSIZEPKT(x) FIELD_PREP(IGC_SRRCTL_BSIZEPKT_MASK, \ + (x) / 1024) /* in 1 KB resolution */ +#define IGC_SRRCTL_BSIZEHDR_MASK GENMASK(13, 8) +#define IGC_SRRCTL_BSIZEHDR(x) FIELD_PREP(IGC_SRRCTL_BSIZEHDR_MASK, \ + (x) / 64) /* in 64 bytes resolution */ +#define IGC_SRRCTL_DESCTYPE_MASK GENMASK(27, 25) +#define IGC_SRRCTL_DESCTYPE_ADV_ONEBUF FIELD_PREP(IGC_SRRCTL_DESCTYPE_MASK, 1) #endif /* _IGC_BASE_H */ diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c index a47dce10d3a78..a8c24a1c12b43 100644 --- a/drivers/net/ethernet/intel/igc/igc_main.c +++ b/drivers/net/ethernet/intel/igc/igc_main.c @@ -674,8 +674,11 @@ static void igc_configure_rx_ring(struct igc_adapter *adapter, else buf_size = IGC_RXBUFFER_2048; - srrctl = IGC_RX_HDR_LEN << IGC_SRRCTL_BSIZEHDRSIZE_SHIFT; - srrctl |= buf_size >> IGC_SRRCTL_BSIZEPKT_SHIFT; + srrctl = rd32(IGC_SRRCTL(reg_idx)); + srrctl &= ~(IGC_SRRCTL_BSIZEPKT_MASK | IGC_SRRCTL_BSIZEHDR_MASK | + IGC_SRRCTL_DESCTYPE_MASK); + srrctl |= IGC_SRRCTL_BSIZEHDR(IGC_RX_HDR_LEN); + srrctl |= IGC_SRRCTL_BSIZEPKT(buf_size); srrctl |= IGC_SRRCTL_DESCTYPE_ADV_ONEBUF; wr32(IGC_SRRCTL(reg_idx), srrctl);