From: John Fastabend Date: Thu, 28 Oct 2010 00:59:57 +0000 (+0000) Subject: ixgbe: DCB, fix TX hang occurring in stress condition with PFC X-Git-Tag: upstream/snapshot3+hdmi~12461^2~118 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9806307a1c5a2a79e268ae4e78b437d38c8adf7f;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git ixgbe: DCB, fix TX hang occurring in stress condition with PFC The DCB credits refill quantum _must_ be greater than half the max packet size. This is needed to guarantee that TX DMA operations are not attempted during a pause state. Additionally, the min IFG must be set correctly for DCB mode. If a DMA operation is requested unexpectedly during the pause state the HW data store may be corrupted leading to a DMA hang. The DMA hang requires a reset to correct. This fixes the HW configuration to avoid this condition. Signed-off-by: John Fastabend Tested-by: Ross Brattain Signed-off-by: Jeff Kirsher Signed-off-by: David S. Miller --- diff --git a/drivers/net/ixgbe/ixgbe_dcb.c b/drivers/net/ixgbe/ixgbe_dcb.c index 8bb9ddb..0d44c64 100644 --- a/drivers/net/ixgbe/ixgbe_dcb.c +++ b/drivers/net/ixgbe/ixgbe_dcb.c @@ -43,9 +43,12 @@ * ixgbe_dcb_check_config(). */ s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_dcb_config *dcb_config, - u8 direction) + int max_frame, u8 direction) { struct tc_bw_alloc *p; + int min_credit; + int min_multiplier; + int min_percent = 100; s32 ret_val = 0; /* Initialization values default for Tx settings */ u32 credit_refill = 0; @@ -59,6 +62,31 @@ s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_dcb_config *dcb_config, goto out; } + min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) / + DCB_CREDIT_QUANTUM; + + /* Find smallest link percentage */ + for (i = 0; i < MAX_TRAFFIC_CLASS; i++) { + p = &dcb_config->tc_config[i].path[direction]; + bw_percent = dcb_config->bw_percentage[direction][p->bwg_id]; + link_percentage = p->bwg_percent; + + link_percentage = (link_percentage * bw_percent) / 100; + + if (link_percentage && link_percentage < min_percent) + min_percent = link_percentage; + } + + /* + * The ratio between traffic classes will control the bandwidth + * percentages seen on the wire. To calculate this ratio we use + * a multiplier. It is required that the refill credits must be + * larger than the max frame size so here we find the smallest + * multiplier that will allow all bandwidth percentages to be + * greater than the max frame size. + */ + min_multiplier = (min_credit / min_percent) + 1; + /* Find out the link percentage for each TC first */ for (i = 0; i < MAX_TRAFFIC_CLASS; i++) { p = &dcb_config->tc_config[i].path[direction]; @@ -73,8 +101,9 @@ s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_dcb_config *dcb_config, /* Save link_percentage for reference */ p->link_percent = (u8)link_percentage; - /* Calculate credit refill and save it */ - credit_refill = link_percentage * MINIMUM_CREDIT_REFILL; + /* Calculate credit refill ratio using multiplier */ + credit_refill = min(link_percentage * min_multiplier, + MAX_CREDIT_REFILL); p->data_credits_refill = (u16)credit_refill; /* Calculate maximum credit for the TC */ @@ -85,8 +114,8 @@ s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_dcb_config *dcb_config, * of a TC is too small, the maximum credit may not be * enough to send out a jumbo frame in data plane arbitration. */ - if (credit_max && (credit_max < MINIMUM_CREDIT_FOR_JUMBO)) - credit_max = MINIMUM_CREDIT_FOR_JUMBO; + if (credit_max && (credit_max < min_credit)) + credit_max = min_credit; if (direction == DCB_TX_CONFIG) { /* diff --git a/drivers/net/ixgbe/ixgbe_dcb.h b/drivers/net/ixgbe/ixgbe_dcb.h index eb1059f..0208a87 100644 --- a/drivers/net/ixgbe/ixgbe_dcb.h +++ b/drivers/net/ixgbe/ixgbe_dcb.h @@ -150,15 +150,14 @@ struct ixgbe_dcb_config { /* DCB driver APIs */ /* DCB credits calculation */ -s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_dcb_config *, u8); +s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_dcb_config *, int, u8); /* DCB hw initialization */ s32 ixgbe_dcb_hw_config(struct ixgbe_hw *, struct ixgbe_dcb_config *); /* DCB definitions for credit calculation */ +#define DCB_CREDIT_QUANTUM 64 /* DCB Quantum */ #define MAX_CREDIT_REFILL 511 /* 0x1FF * 64B = 32704B */ -#define MINIMUM_CREDIT_REFILL 5 /* 5*64B = 320B */ -#define MINIMUM_CREDIT_FOR_JUMBO 145 /* 145= UpperBound((9*1024+54)/64B) for 9KB jumbo frame */ #define DCB_MAX_TSO_SIZE (32*1024) /* MAX TSO packet size supported in DCB mode */ #define MINIMUM_CREDIT_FOR_TSO (DCB_MAX_TSO_SIZE/64 + 1) /* 513 for 32KB TSO packet */ #define MAX_CREDIT 4095 /* Maximum credit supported: 256KB * 1204 / 64B */ diff --git a/drivers/net/ixgbe/ixgbe_dcb_82599.c b/drivers/net/ixgbe/ixgbe_dcb_82599.c index 67c219f..05f2247 100644 --- a/drivers/net/ixgbe/ixgbe_dcb_82599.c +++ b/drivers/net/ixgbe/ixgbe_dcb_82599.c @@ -397,6 +397,11 @@ static s32 ixgbe_dcb_config_82599(struct ixgbe_hw *hw) reg &= ~IXGBE_RTTDCS_ARBDIS; IXGBE_WRITE_REG(hw, IXGBE_RTTDCS, reg); + /* Enable Security TX Buffer IFG for DCB */ + reg = IXGBE_READ_REG(hw, IXGBE_SECTXMINIFG); + reg |= IXGBE_SECTX_DCB; + IXGBE_WRITE_REG(hw, IXGBE_SECTXMINIFG, reg); + return 0; } diff --git a/drivers/net/ixgbe/ixgbe_dcb_82599.h b/drivers/net/ixgbe/ixgbe_dcb_82599.h index 18d7fbf..3841649 100644 --- a/drivers/net/ixgbe/ixgbe_dcb_82599.h +++ b/drivers/net/ixgbe/ixgbe_dcb_82599.h @@ -95,6 +95,9 @@ #define IXGBE_TXPBTHRESH_DCB 0xA /* THRESH value for DCB mode */ +/* SECTXMINIFG DCB */ +#define IXGBE_SECTX_DCB 0x00001F00 /* DCB TX Buffer IFG */ + /* DCB hardware-specific driver APIs */ diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c index f856312..2bd3eb4 100644 --- a/drivers/net/ixgbe/ixgbe_main.c +++ b/drivers/net/ixgbe/ixgbe_main.c @@ -3347,6 +3347,7 @@ static void ixgbe_napi_disable_all(struct ixgbe_adapter *adapter) static void ixgbe_configure_dcb(struct ixgbe_adapter *adapter) { struct ixgbe_hw *hw = &adapter->hw; + int max_frame = adapter->netdev->mtu + ETH_HLEN + ETH_FCS_LEN; u32 txdctl; int i, j; @@ -3359,8 +3360,15 @@ static void ixgbe_configure_dcb(struct ixgbe_adapter *adapter) if (hw->mac.type == ixgbe_mac_82598EB) netif_set_gso_max_size(adapter->netdev, 32768); - ixgbe_dcb_calculate_tc_credits(&adapter->dcb_cfg, DCB_TX_CONFIG); - ixgbe_dcb_calculate_tc_credits(&adapter->dcb_cfg, DCB_RX_CONFIG); +#ifdef CONFIG_FCOE + if (adapter->netdev->features & NETIF_F_FCOE_MTU) + max_frame = max(max_frame, IXGBE_FCOE_JUMBO_FRAME_SIZE); +#endif + + ixgbe_dcb_calculate_tc_credits(&adapter->dcb_cfg, max_frame, + DCB_TX_CONFIG); + ixgbe_dcb_calculate_tc_credits(&adapter->dcb_cfg, max_frame, + DCB_RX_CONFIG); /* reconfigure the hardware */ ixgbe_dcb_hw_config(&adapter->hw, &adapter->dcb_cfg);