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Message-ID: <20090313071409.21994.98644.stgit@speedy5>
Date: Fri, 13 Mar 2009 00:14:09 -0700
From: Divy Le Ray <divy@...lsio.com>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
swise@...ngridcomputing.com
Subject: [PATCH net-next 6/10] cxgb3: disable high freq non-data interrupts
From: Divy Le Ray <divy@...lsio.com>
Under RX pressure, The HW might generate a high load of interrupts
to signal mac fifo or free lists overflow.
Disable the interrupts, and poll the relevant status bits
to maintain stats.
Signed-off-by: Divy Le Ray <divy@...lsio.com>
---
drivers/net/cxgb3/cxgb3_main.c | 50 ++++++++++++++++++++++++++++++++++++++++
drivers/net/cxgb3/regs.h | 8 ++++++
drivers/net/cxgb3/sge.c | 3 ++
drivers/net/cxgb3/t3_hw.c | 30 +++++++++++++++++++++---
4 files changed, 86 insertions(+), 5 deletions(-)
diff --git a/drivers/net/cxgb3/cxgb3_main.c b/drivers/net/cxgb3/cxgb3_main.c
index c32f514..9ff0452 100644
--- a/drivers/net/cxgb3/cxgb3_main.c
+++ b/drivers/net/cxgb3/cxgb3_main.c
@@ -2471,6 +2471,8 @@ static void t3_adap_check_task(struct work_struct *work)
struct adapter *adapter = container_of(work, struct adapter,
adap_check_task.work);
const struct adapter_params *p = &adapter->params;
+ int port;
+ unsigned int v, status, reset;
adapter->check_task_cnt++;
@@ -2489,6 +2491,54 @@ static void t3_adap_check_task(struct work_struct *work)
if (p->rev == T3_REV_B2)
check_t3b2_mac(adapter);
+ /*
+ * Scan the XGMAC's to check for various conditions which we want to
+ * monitor in a periodic polling manner rather than via an interrupt
+ * condition. This is used for conditions which would otherwise flood
+ * the system with interrupts and we only really need to know that the
+ * conditions are "happening" ... For each condition we count the
+ * detection of the condition and reset it for the next polling loop.
+ */
+ for_each_port(adapter, port) {
+ struct cmac *mac = &adap2pinfo(adapter, port)->mac;
+ u32 cause;
+
+ cause = t3_read_reg(adapter, A_XGM_INT_CAUSE + mac->offset);
+ reset = 0;
+ if (cause & F_RXFIFO_OVERFLOW) {
+ mac->stats.rx_fifo_ovfl++;
+ reset |= F_RXFIFO_OVERFLOW;
+ }
+
+ t3_write_reg(adapter, A_XGM_INT_CAUSE + mac->offset, reset);
+ }
+
+ /*
+ * We do the same as above for FL_EMPTY interrupts.
+ */
+ status = t3_read_reg(adapter, A_SG_INT_CAUSE);
+ reset = 0;
+
+ if (status & F_FLEMPTY) {
+ struct sge_qset *qs = &adapter->sge.qs[0];
+ int i = 0;
+
+ reset |= F_FLEMPTY;
+
+ v = (t3_read_reg(adapter, A_SG_RSPQ_FL_STATUS) >> S_FL0EMPTY) &
+ 0xffff;
+
+ while (v) {
+ qs->fl[i].empty += (v & 1);
+ if (i)
+ qs++;
+ i ^= 1;
+ v >>= 1;
+ }
+ }
+
+ t3_write_reg(adapter, A_SG_INT_CAUSE, reset);
+
/* Schedule the next check update if any port is active. */
spin_lock_irq(&adapter->work_lock);
if (adapter->open_device_map & PORT_MASK)
diff --git a/drivers/net/cxgb3/regs.h b/drivers/net/cxgb3/regs.h
index a035d5c..aa08550 100644
--- a/drivers/net/cxgb3/regs.h
+++ b/drivers/net/cxgb3/regs.h
@@ -170,6 +170,10 @@
#define S_RSPQ0DISABLED 8
+#define S_FL0EMPTY 16
+#define V_FL0EMPTY(x) ((x) << S_FL0EMPTY)
+#define F_FL0EMPTY V_FL0EMPTY(1U)
+
#define A_SG_EGR_RCQ_DRB_THRSH 0x54
#define S_HIRCQDRBTHRSH 16
@@ -258,6 +262,10 @@
#define V_RSPQCREDITOVERFOW(x) ((x) << S_RSPQCREDITOVERFOW)
#define F_RSPQCREDITOVERFOW V_RSPQCREDITOVERFOW(1U)
+#define S_FLEMPTY 1
+#define V_FLEMPTY(x) ((x) << S_FLEMPTY)
+#define F_FLEMPTY V_FLEMPTY(1U)
+
#define A_SG_INT_ENABLE 0x60
#define A_SG_CMDQ_CREDIT_TH 0x64
diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c
index 7d779d1..a7555cb 100644
--- a/drivers/net/cxgb3/sge.c
+++ b/drivers/net/cxgb3/sge.c
@@ -2725,7 +2725,8 @@ irq_handler_t t3_intr_handler(struct adapter *adap, int polling)
*/
void t3_sge_err_intr_handler(struct adapter *adapter)
{
- unsigned int v, status = t3_read_reg(adapter, A_SG_INT_CAUSE);
+ unsigned int v, status = t3_read_reg(adapter, A_SG_INT_CAUSE) &
+ ~F_FLEMPTY;
if (status & SGE_PARERR)
CH_ALERT(adapter, "SGE parity error (0x%x)\n",
diff --git a/drivers/net/cxgb3/t3_hw.c b/drivers/net/cxgb3/t3_hw.c
index ac2a974..7c6ee0c 100644
--- a/drivers/net/cxgb3/t3_hw.c
+++ b/drivers/net/cxgb3/t3_hw.c
@@ -1323,7 +1323,7 @@ static int t3_handle_intr_status(struct adapter *adapter, unsigned int reg,
#define MC7_INTR_MASK (F_AE | F_UE | F_CE | V_PE(M_PE))
#define XGM_INTR_MASK (V_TXFIFO_PRTY_ERR(M_TXFIFO_PRTY_ERR) | \
V_RXFIFO_PRTY_ERR(M_RXFIFO_PRTY_ERR) | \
- F_TXFIFO_UNDERRUN | F_RXFIFO_OVERFLOW)
+ F_TXFIFO_UNDERRUN)
#define PCIX_INTR_MASK (F_MSTDETPARERR | F_SIGTARABT | F_RCVTARABT | \
F_RCVMSTABT | F_SIGSYSERR | F_DETPARERR | \
F_SPLCMPDIS | F_UNXSPLCMP | F_RCVSPLCMPERR | \
@@ -1695,7 +1695,14 @@ static void mc7_intr_handler(struct mc7 *mc7)
static int mac_intr_handler(struct adapter *adap, unsigned int idx)
{
struct cmac *mac = &adap2pinfo(adap, idx)->mac;
- u32 cause = t3_read_reg(adap, A_XGM_INT_CAUSE + mac->offset);
+ /*
+ * We mask out interrupt causes for which we're not taking interrupts.
+ * This allows us to use polling logic to monitor some of the other
+ * conditions when taking interrupts would impose too much load on the
+ * system.
+ */
+ u32 cause = t3_read_reg(adap, A_XGM_INT_CAUSE + mac->offset) &
+ ~F_RXFIFO_OVERFLOW;
if (cause & V_TXFIFO_PRTY_ERR(M_TXFIFO_PRTY_ERR)) {
mac->stats.tx_fifo_parity_err++;
@@ -3617,7 +3624,15 @@ int t3_prep_adapter(struct adapter *adapter, const struct adapter_info *ai,
adapter->params.info = ai;
adapter->params.nports = ai->nports;
adapter->params.rev = t3_read_reg(adapter, A_PL_REV);
- adapter->params.linkpoll_period = 0;
+ /*
+ * We used to only run the "adapter check task" once a second if
+ * we had PHYs which didn't support interrupts (we would check
+ * their link status once a second). Now we check other conditions
+ * in that routine which could potentially impose a very high
+ * interrupt load on the system. As such, we now always scan the
+ * adapter state once a second ...
+ */
+ adapter->params.linkpoll_period = 10;
adapter->params.stats_update_period = is_10G(adapter) ?
MAC_STATS_ACCUM_SECS : (MAC_STATS_ACCUM_SECS * 10);
adapter->params.pci.vpd_cap_addr =
@@ -3707,7 +3722,14 @@ int t3_prep_adapter(struct adapter *adapter, const struct adapter_info *ai,
ETH_ALEN);
init_link_config(&p->link_config, p->phy.caps);
p->phy.ops->power_down(&p->phy, 1);
- if (!(p->phy.caps & SUPPORTED_IRQ))
+
+ /*
+ * If the PHY doesn't support interrupts for link status
+ * changes, schedule a scan of the adapter links at least
+ * once a second.
+ */
+ if (!(p->phy.caps & SUPPORTED_IRQ) &&
+ adapter->params.linkpoll_period > 10)
adapter->params.linkpoll_period = 10;
}
--
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