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e5df49d564
Below is a description of a possible problematic
sequence. CPU-A is sending a frame and CPU-B handles
the interrupt that indicates the frame was sent. CPU-B
reads an invalid value of tx_packet_sent.
CPU-A CPU-B
----- -----
nps_enet_send_frame
.
.
tx_skb = skb
tx_packet_sent = true
order HW to start tx
.
.
HW complete tx
------> get tx complete interrupt
.
.
if(tx_packet_sent == true)
handle tx_skb
end memory transaction
(tx_packet_sent actually
written)
Furthermore there is a dependency between tx_skb and tx_packet_sent.
There is no assurance that tx_skb contains a valid pointer at CPU B
when it sees tx_packet_sent == true.
Solution:
Initialize tx_skb to NULL and use it to indicate that packet was sent,
in this way tx_packet_sent can be removed.
Add a write memory barrier after setting tx_skb in order to make sure
that it is valid before HW is informed and IRQ is fired.
Fixed sequence will be:
CPU-A CPU-B
----- -----
tx_skb = skb
wmb()
.
.
order HW to start tx
.
.
HW complete tx
------> get tx complete interrupt
.
.
if(tx_skb != NULL)
handle tx_skb
tx_skb = NULL
Signed-off-by: Elad Kanfi <eladkan@mellanox.com>
Acked-by: Noam Camus <noamca@mellanox.com>
Acked-by: Gilad Ben-Yossef <giladby@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
205 lines
6.5 KiB
C
205 lines
6.5 KiB
C
/*
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* Copyright(c) 2015 EZchip Technologies.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* The full GNU General Public License is included in this distribution in
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* the file called "COPYING".
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*/
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#ifndef _NPS_ENET_H
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#define _NPS_ENET_H
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/* default values */
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#define NPS_ENET_NAPI_POLL_WEIGHT 0x2
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#define NPS_ENET_MAX_FRAME_LENGTH 0x3FFF
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#define NPS_ENET_GE_MAC_CFG_0_TX_FC_RETR 0x7
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#define NPS_ENET_GE_MAC_CFG_0_RX_IFG 0x5
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#define NPS_ENET_GE_MAC_CFG_0_TX_IFG 0xC
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#define NPS_ENET_GE_MAC_CFG_0_TX_PR_LEN 0x7
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#define NPS_ENET_GE_MAC_CFG_2_STAT_EN 0x3
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#define NPS_ENET_GE_MAC_CFG_3_RX_IFG_TH 0x14
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#define NPS_ENET_GE_MAC_CFG_3_MAX_LEN 0x3FFC
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#define NPS_ENET_ENABLE 1
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#define NPS_ENET_DISABLE 0
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/* register definitions */
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#define NPS_ENET_REG_TX_CTL 0x800
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#define NPS_ENET_REG_TX_BUF 0x808
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#define NPS_ENET_REG_RX_CTL 0x810
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#define NPS_ENET_REG_RX_BUF 0x818
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#define NPS_ENET_REG_BUF_INT_ENABLE 0x8C0
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#define NPS_ENET_REG_GE_MAC_CFG_0 0x1000
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#define NPS_ENET_REG_GE_MAC_CFG_1 0x1004
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#define NPS_ENET_REG_GE_MAC_CFG_2 0x1008
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#define NPS_ENET_REG_GE_MAC_CFG_3 0x100C
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#define NPS_ENET_REG_GE_RST 0x1400
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#define NPS_ENET_REG_PHASE_FIFO_CTL 0x1404
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/* Tx control register masks and shifts */
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#define TX_CTL_NT_MASK 0x7FF
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#define TX_CTL_NT_SHIFT 0
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#define TX_CTL_ET_MASK 0x4000
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#define TX_CTL_ET_SHIFT 14
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#define TX_CTL_CT_MASK 0x8000
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#define TX_CTL_CT_SHIFT 15
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/* Rx control register masks and shifts */
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#define RX_CTL_NR_MASK 0x7FF
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#define RX_CTL_NR_SHIFT 0
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#define RX_CTL_CRC_MASK 0x2000
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#define RX_CTL_CRC_SHIFT 13
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#define RX_CTL_ER_MASK 0x4000
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#define RX_CTL_ER_SHIFT 14
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#define RX_CTL_CR_MASK 0x8000
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#define RX_CTL_CR_SHIFT 15
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/* Interrupt enable for data buffer events register masks and shifts */
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#define RX_RDY_MASK 0x1
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#define RX_RDY_SHIFT 0
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#define TX_DONE_MASK 0x2
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#define TX_DONE_SHIFT 1
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/* Gbps Eth MAC Configuration 0 register masks and shifts */
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#define CFG_0_RX_EN_MASK 0x1
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#define CFG_0_RX_EN_SHIFT 0
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#define CFG_0_TX_EN_MASK 0x2
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#define CFG_0_TX_EN_SHIFT 1
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#define CFG_0_TX_FC_EN_MASK 0x4
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#define CFG_0_TX_FC_EN_SHIFT 2
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#define CFG_0_TX_PAD_EN_MASK 0x8
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#define CFG_0_TX_PAD_EN_SHIFT 3
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#define CFG_0_TX_CRC_EN_MASK 0x10
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#define CFG_0_TX_CRC_EN_SHIFT 4
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#define CFG_0_RX_FC_EN_MASK 0x20
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#define CFG_0_RX_FC_EN_SHIFT 5
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#define CFG_0_RX_CRC_STRIP_MASK 0x40
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#define CFG_0_RX_CRC_STRIP_SHIFT 6
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#define CFG_0_RX_CRC_IGNORE_MASK 0x80
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#define CFG_0_RX_CRC_IGNORE_SHIFT 7
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#define CFG_0_RX_LENGTH_CHECK_EN_MASK 0x100
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#define CFG_0_RX_LENGTH_CHECK_EN_SHIFT 8
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#define CFG_0_TX_FC_RETR_MASK 0xE00
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#define CFG_0_TX_FC_RETR_SHIFT 9
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#define CFG_0_RX_IFG_MASK 0xF000
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#define CFG_0_RX_IFG_SHIFT 12
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#define CFG_0_TX_IFG_MASK 0x3F0000
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#define CFG_0_TX_IFG_SHIFT 16
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#define CFG_0_RX_PR_CHECK_EN_MASK 0x400000
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#define CFG_0_RX_PR_CHECK_EN_SHIFT 22
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#define CFG_0_NIB_MODE_MASK 0x800000
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#define CFG_0_NIB_MODE_SHIFT 23
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#define CFG_0_TX_IFG_NIB_MASK 0xF000000
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#define CFG_0_TX_IFG_NIB_SHIFT 24
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#define CFG_0_TX_PR_LEN_MASK 0xF0000000
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#define CFG_0_TX_PR_LEN_SHIFT 28
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/* Gbps Eth MAC Configuration 1 register masks and shifts */
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#define CFG_1_OCTET_0_MASK 0x000000FF
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#define CFG_1_OCTET_0_SHIFT 0
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#define CFG_1_OCTET_1_MASK 0x0000FF00
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#define CFG_1_OCTET_1_SHIFT 8
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#define CFG_1_OCTET_2_MASK 0x00FF0000
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#define CFG_1_OCTET_2_SHIFT 16
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#define CFG_1_OCTET_3_MASK 0xFF000000
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#define CFG_1_OCTET_3_SHIFT 24
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/* Gbps Eth MAC Configuration 2 register masks and shifts */
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#define CFG_2_OCTET_4_MASK 0x000000FF
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#define CFG_2_OCTET_4_SHIFT 0
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#define CFG_2_OCTET_5_MASK 0x0000FF00
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#define CFG_2_OCTET_5_SHIFT 8
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#define CFG_2_DISK_MC_MASK 0x00100000
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#define CFG_2_DISK_MC_SHIFT 20
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#define CFG_2_DISK_BC_MASK 0x00200000
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#define CFG_2_DISK_BC_SHIFT 21
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#define CFG_2_DISK_DA_MASK 0x00400000
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#define CFG_2_DISK_DA_SHIFT 22
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#define CFG_2_STAT_EN_MASK 0x3000000
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#define CFG_2_STAT_EN_SHIFT 24
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#define CFG_2_TRANSMIT_FLUSH_EN_MASK 0x80000000
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#define CFG_2_TRANSMIT_FLUSH_EN_SHIFT 31
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/* Gbps Eth MAC Configuration 3 register masks and shifts */
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#define CFG_3_TM_HD_MODE_MASK 0x1
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#define CFG_3_TM_HD_MODE_SHIFT 0
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#define CFG_3_RX_CBFC_EN_MASK 0x2
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#define CFG_3_RX_CBFC_EN_SHIFT 1
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#define CFG_3_RX_CBFC_REDIR_EN_MASK 0x4
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#define CFG_3_RX_CBFC_REDIR_EN_SHIFT 2
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#define CFG_3_REDIRECT_CBFC_SEL_MASK 0x18
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#define CFG_3_REDIRECT_CBFC_SEL_SHIFT 3
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#define CFG_3_CF_DROP_MASK 0x20
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#define CFG_3_CF_DROP_SHIFT 5
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#define CFG_3_CF_TIMEOUT_MASK 0x3C0
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#define CFG_3_CF_TIMEOUT_SHIFT 6
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#define CFG_3_RX_IFG_TH_MASK 0x7C00
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#define CFG_3_RX_IFG_TH_SHIFT 10
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#define CFG_3_TX_CBFC_EN_MASK 0x8000
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#define CFG_3_TX_CBFC_EN_SHIFT 15
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#define CFG_3_MAX_LEN_MASK 0x3FFF0000
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#define CFG_3_MAX_LEN_SHIFT 16
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#define CFG_3_EXT_OOB_CBFC_SEL_MASK 0xC0000000
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#define CFG_3_EXT_OOB_CBFC_SEL_SHIFT 30
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/* GE MAC, PCS reset control register masks and shifts */
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#define RST_SPCS_MASK 0x1
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#define RST_SPCS_SHIFT 0
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#define RST_GMAC_0_MASK 0x100
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#define RST_GMAC_0_SHIFT 8
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/* Tx phase sync FIFO control register masks and shifts */
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#define PHASE_FIFO_CTL_RST_MASK 0x1
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#define PHASE_FIFO_CTL_RST_SHIFT 0
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#define PHASE_FIFO_CTL_INIT_MASK 0x2
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#define PHASE_FIFO_CTL_INIT_SHIFT 1
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/**
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* struct nps_enet_priv - Storage of ENET's private information.
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* @regs_base: Base address of ENET memory-mapped control registers.
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* @irq: For RX/TX IRQ number.
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* @tx_skb: socket buffer of sent frame.
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* @napi: Structure for NAPI.
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*/
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struct nps_enet_priv {
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void __iomem *regs_base;
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s32 irq;
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struct sk_buff *tx_skb;
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struct napi_struct napi;
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u32 ge_mac_cfg_2_value;
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u32 ge_mac_cfg_3_value;
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};
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/**
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* nps_reg_set - Sets ENET register with provided value.
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* @priv: Pointer to EZchip ENET private data structure.
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* @reg: Register offset from base address.
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* @value: Value to set in register.
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*/
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static inline void nps_enet_reg_set(struct nps_enet_priv *priv,
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s32 reg, s32 value)
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{
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iowrite32be(value, priv->regs_base + reg);
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}
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/**
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* nps_reg_get - Gets value of specified ENET register.
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* @priv: Pointer to EZchip ENET private data structure.
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* @reg: Register offset from base address.
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*
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* returns: Value of requested register.
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*/
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static inline u32 nps_enet_reg_get(struct nps_enet_priv *priv, s32 reg)
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{
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return ioread32be(priv->regs_base + reg);
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}
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#endif /* _NPS_ENET_H */
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