This is a note to let you know that I've just added the patch titled sfc: get PIO buffer size from the NIC to the 4.9-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: sfc-get-pio-buffer-size-from-the-nic.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Thu Oct 5 10:28:31 CEST 2017 From: Edward Cree <ecree@xxxxxxxxxxxxxx> Date: Fri, 13 Jan 2017 21:20:29 +0000 Subject: sfc: get PIO buffer size from the NIC From: Edward Cree <ecree@xxxxxxxxxxxxxx> [ Upstream commit c634700f7eec3c0da46e299cd0a0ae8b594f9b55 ] The 8000 series SFC NICs have 4K PIO buffers, rather than the 2K of the 7000 series. Rather than having a hard-coded PIO buffer size (ER_DZ_TX_PIOBUF_SIZE), read it from the GET_CAPABILITIES_V2 MCDI response. Signed-off-by: Edward Cree <ecree@xxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/ethernet/sfc/ef10.c | 16 ++++++++++------ drivers/net/ethernet/sfc/nic.h | 2 ++ drivers/net/ethernet/sfc/tx.c | 1 - 3 files changed, 12 insertions(+), 7 deletions(-) --- a/drivers/net/ethernet/sfc/ef10.c +++ b/drivers/net/ethernet/sfc/ef10.c @@ -197,11 +197,15 @@ static int efx_ef10_init_datapath_caps(s nic_data->datapath_caps = MCDI_DWORD(outbuf, GET_CAPABILITIES_OUT_FLAGS1); - if (outlen >= MC_CMD_GET_CAPABILITIES_V2_OUT_LEN) + if (outlen >= MC_CMD_GET_CAPABILITIES_V2_OUT_LEN) { nic_data->datapath_caps2 = MCDI_DWORD(outbuf, GET_CAPABILITIES_V2_OUT_FLAGS2); - else + nic_data->piobuf_size = MCDI_WORD(outbuf, + GET_CAPABILITIES_V2_OUT_SIZE_PIO_BUFF); + } else { nic_data->datapath_caps2 = 0; + nic_data->piobuf_size = ER_DZ_TX_PIOBUF_SIZE; + } /* record the DPCPU firmware IDs to determine VEB vswitching support. */ @@ -825,8 +829,8 @@ static int efx_ef10_link_piobufs(struct offset = ((efx->tx_channel_offset + efx->n_tx_channels - tx_queue->channel->channel - 1) * efx_piobuf_size); - index = offset / ER_DZ_TX_PIOBUF_SIZE; - offset = offset % ER_DZ_TX_PIOBUF_SIZE; + index = offset / nic_data->piobuf_size; + offset = offset % nic_data->piobuf_size; /* When the host page size is 4K, the first * host page in the WC mapping may be within @@ -1161,11 +1165,11 @@ static int efx_ef10_dimension_resources( * functions of the controller. */ if (efx_piobuf_size != 0 && - ER_DZ_TX_PIOBUF_SIZE / efx_piobuf_size * EF10_TX_PIOBUF_COUNT >= + nic_data->piobuf_size / efx_piobuf_size * EF10_TX_PIOBUF_COUNT >= efx->n_tx_channels) { unsigned int n_piobufs = DIV_ROUND_UP(efx->n_tx_channels, - ER_DZ_TX_PIOBUF_SIZE / efx_piobuf_size); + nic_data->piobuf_size / efx_piobuf_size); rc = efx_ef10_alloc_piobufs(efx, n_piobufs); if (rc) --- a/drivers/net/ethernet/sfc/nic.h +++ b/drivers/net/ethernet/sfc/nic.h @@ -500,6 +500,7 @@ enum { * @pio_write_base: Base address for writing PIO buffers * @pio_write_vi_base: Relative VI number for @pio_write_base * @piobuf_handle: Handle of each PIO buffer allocated + * @piobuf_size: size of a single PIO buffer * @must_restore_piobufs: Flag: PIO buffers have yet to be restored after MC * reboot * @rx_rss_context: Firmware handle for our RSS context @@ -537,6 +538,7 @@ struct efx_ef10_nic_data { void __iomem *wc_membase, *pio_write_base; unsigned int pio_write_vi_base; unsigned int piobuf_handle[EF10_TX_PIOBUF_COUNT]; + u16 piobuf_size; bool must_restore_piobufs; u32 rx_rss_context; bool rx_rss_context_exclusive; --- a/drivers/net/ethernet/sfc/tx.c +++ b/drivers/net/ethernet/sfc/tx.c @@ -27,7 +27,6 @@ #ifdef EFX_USE_PIO -#define EFX_PIOBUF_SIZE_MAX ER_DZ_TX_PIOBUF_SIZE #define EFX_PIOBUF_SIZE_DEF ALIGN(256, L1_CACHE_BYTES) unsigned int efx_piobuf_size __read_mostly = EFX_PIOBUF_SIZE_DEF; Patches currently in stable-queue which might be from ecree@xxxxxxxxxxxxxx are queue-4.9/sfc-get-pio-buffer-size-from-the-nic.patch