[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <20101028105957.27748.39154.stgit@localhost6.localdomain6>
Date: Thu, 28 Oct 2010 03:59:57 -0700
From: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org, gospo@...hat.com, bphilips@...ell.com,
John Fastabend <john.r.fastabend@...el.com>,
Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-2.6 PATCH] ixgbe: DCB,
fix TX hang occurring in stress condition with PFC
From: John Fastabend <john.r.fastabend@...el.com>
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 <john.r.fastabend@...el.com>
Tested-by: Ross Brattain <ross.b.brattain@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---
drivers/net/ixgbe/ixgbe_dcb.c | 39 +++++++++++++++++++++++++++++++----
drivers/net/ixgbe/ixgbe_dcb.h | 5 ++--
drivers/net/ixgbe/ixgbe_dcb_82599.c | 5 ++++
drivers/net/ixgbe/ixgbe_dcb_82599.h | 3 +++
drivers/net/ixgbe/ixgbe_main.c | 12 +++++++++--
5 files changed, 54 insertions(+), 10 deletions(-)
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);
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists