cxgb4: DB Drop Recovery for RDMA and LLD queues
recover LLD EQs for DB drop interrupts. This includes adding a new
db_lock, a spin lock disabling BH too, used by the recovery thread and
the ring_tx_db() paths to allow db drop recovery.
Clean up initial DB avoidance code.
Add read_eq_indices() - this allows the LLD to use the PCIe mw to
efficiently read hw eq contexts.
Add cxgb4_sync_txq_pidx() - called by iw_cxgb4 to sync up the sw/hw
pidx value.
Add flush_eq_cache() and cxgb4_flush_eq_cache(). This allows iw_cxgb4
to flush the sge eq context cache before beginning db drop recovery.
Add module parameter, dbfoifo_int_thresh, to allow tuning the db
interrupt threshold value.
Add dbfifo_int_thresh to cxgb4_lld_info so iw_cxgb4 knows the threshold.
Add module parameter, dbfoifo_drain_delay, to allow tuning the amount
of time delay between DB FULL and EMPTY upcalls to iw_cxgb4.
Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
index 5f3c0a7..ec2dafe 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4.h
@@ -51,6 +51,8 @@
#define FW_VERSION_MINOR 1
#define FW_VERSION_MICRO 0
+#define CH_WARN(adap, fmt, ...) dev_warn(adap->pdev_dev, fmt, ## __VA_ARGS__)
+
enum {
MAX_NPORTS = 4, /* max # of ports */
SERNUM_LEN = 24, /* Serial # length */
@@ -64,6 +66,15 @@
MEM_MC
};
+enum {
+ MEMWIN0_APERTURE = 65536,
+ MEMWIN0_BASE = 0x30000,
+ MEMWIN1_APERTURE = 32768,
+ MEMWIN1_BASE = 0x28000,
+ MEMWIN2_APERTURE = 2048,
+ MEMWIN2_BASE = 0x1b800,
+};
+
enum dev_master {
MASTER_CANT,
MASTER_MAY,
@@ -403,6 +414,9 @@
struct tx_sw_desc *sdesc; /* address of SW Tx descriptor ring */
struct sge_qstat *stat; /* queue status entry */
dma_addr_t phys_addr; /* physical address of the ring */
+ spinlock_t db_lock;
+ int db_disabled;
+ unsigned short db_pidx;
};
struct sge_eth_txq { /* state for an SGE Ethernet Tx queue */
@@ -475,6 +489,7 @@
void __iomem *regs;
struct pci_dev *pdev;
struct device *pdev_dev;
+ unsigned int mbox;
unsigned int fn;
unsigned int flags;
@@ -607,6 +622,7 @@
void t4_sge_init(struct adapter *adap);
void t4_sge_start(struct adapter *adap);
void t4_sge_stop(struct adapter *adap);
+extern int dbfifo_int_thresh;
#define for_each_port(adapter, iter) \
for (iter = 0; iter < (adapter)->params.nports; ++iter)
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
index c243f93..e1f96fb 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
@@ -149,15 +149,6 @@
#endif
enum {
- MEMWIN0_APERTURE = 65536,
- MEMWIN0_BASE = 0x30000,
- MEMWIN1_APERTURE = 32768,
- MEMWIN1_BASE = 0x28000,
- MEMWIN2_APERTURE = 2048,
- MEMWIN2_BASE = 0x1b800,
-};
-
-enum {
MAX_TXQ_ENTRIES = 16384,
MAX_CTRL_TXQ_ENTRIES = 1024,
MAX_RSPQ_ENTRIES = 16384,
@@ -371,6 +362,15 @@
uhash | mhash, sleep);
}
+int dbfifo_int_thresh = 10; /* 10 == 640 entry threshold */
+module_param(dbfifo_int_thresh, int, 0644);
+MODULE_PARM_DESC(dbfifo_int_thresh, "doorbell fifo interrupt threshold");
+
+int dbfifo_drain_delay = 1000; /* usecs to sleep while draining the dbfifo */
+module_param(dbfifo_drain_delay, int, 0644);
+MODULE_PARM_DESC(dbfifo_drain_delay,
+ "usecs to sleep while draining the dbfifo");
+
/*
* Set Rx properties of a port, such as promiscruity, address filters, and MTU.
* If @mtu is -1 it is left unchanged.
@@ -389,6 +389,8 @@
return ret;
}
+static struct workqueue_struct *workq;
+
/**
* link_start - enable a port
* @dev: the port to enable
@@ -2196,7 +2198,7 @@
adap->tid_release_head = (void **)((uintptr_t)p | chan);
if (!adap->tid_release_task_busy) {
adap->tid_release_task_busy = true;
- schedule_work(&adap->tid_release_task);
+ queue_work(workq, &adap->tid_release_task);
}
spin_unlock_bh(&adap->tid_release_lock);
}
@@ -2423,6 +2425,59 @@
}
EXPORT_SYMBOL(cxgb4_iscsi_init);
+int cxgb4_flush_eq_cache(struct net_device *dev)
+{
+ struct adapter *adap = netdev2adap(dev);
+ int ret;
+
+ ret = t4_fwaddrspace_write(adap, adap->mbox,
+ 0xe1000000 + A_SGE_CTXT_CMD, 0x20000000);
+ return ret;
+}
+EXPORT_SYMBOL(cxgb4_flush_eq_cache);
+
+static int read_eq_indices(struct adapter *adap, u16 qid, u16 *pidx, u16 *cidx)
+{
+ u32 addr = t4_read_reg(adap, A_SGE_DBQ_CTXT_BADDR) + 24 * qid + 8;
+ __be64 indices;
+ int ret;
+
+ ret = t4_mem_win_read_len(adap, addr, (__be32 *)&indices, 8);
+ if (!ret) {
+ indices = be64_to_cpu(indices);
+ *cidx = (indices >> 25) & 0xffff;
+ *pidx = (indices >> 9) & 0xffff;
+ }
+ return ret;
+}
+
+int cxgb4_sync_txq_pidx(struct net_device *dev, u16 qid, u16 pidx,
+ u16 size)
+{
+ struct adapter *adap = netdev2adap(dev);
+ u16 hw_pidx, hw_cidx;
+ int ret;
+
+ ret = read_eq_indices(adap, qid, &hw_pidx, &hw_cidx);
+ if (ret)
+ goto out;
+
+ if (pidx != hw_pidx) {
+ u16 delta;
+
+ if (pidx >= hw_pidx)
+ delta = pidx - hw_pidx;
+ else
+ delta = size - hw_pidx + pidx;
+ wmb();
+ t4_write_reg(adap, MYPF_REG(A_SGE_PF_KDOORBELL),
+ V_QID(qid) | V_PIDX(delta));
+ }
+out:
+ return ret;
+}
+EXPORT_SYMBOL(cxgb4_sync_txq_pidx);
+
static struct pci_driver cxgb4_driver;
static void check_neigh_update(struct neighbour *neigh)
@@ -2456,6 +2511,95 @@
.notifier_call = netevent_cb
};
+static void drain_db_fifo(struct adapter *adap, int usecs)
+{
+ u32 v;
+
+ do {
+ set_current_state(TASK_UNINTERRUPTIBLE);
+ schedule_timeout(usecs_to_jiffies(usecs));
+ v = t4_read_reg(adap, A_SGE_DBFIFO_STATUS);
+ if (G_LP_COUNT(v) == 0 && G_HP_COUNT(v) == 0)
+ break;
+ } while (1);
+}
+
+static void disable_txq_db(struct sge_txq *q)
+{
+ spin_lock_irq(&q->db_lock);
+ q->db_disabled = 1;
+ spin_unlock_irq(&q->db_lock);
+}
+
+static void enable_txq_db(struct sge_txq *q)
+{
+ spin_lock_irq(&q->db_lock);
+ q->db_disabled = 0;
+ spin_unlock_irq(&q->db_lock);
+}
+
+static void disable_dbs(struct adapter *adap)
+{
+ int i;
+
+ for_each_ethrxq(&adap->sge, i)
+ disable_txq_db(&adap->sge.ethtxq[i].q);
+ for_each_ofldrxq(&adap->sge, i)
+ disable_txq_db(&adap->sge.ofldtxq[i].q);
+ for_each_port(adap, i)
+ disable_txq_db(&adap->sge.ctrlq[i].q);
+}
+
+static void enable_dbs(struct adapter *adap)
+{
+ int i;
+
+ for_each_ethrxq(&adap->sge, i)
+ enable_txq_db(&adap->sge.ethtxq[i].q);
+ for_each_ofldrxq(&adap->sge, i)
+ enable_txq_db(&adap->sge.ofldtxq[i].q);
+ for_each_port(adap, i)
+ enable_txq_db(&adap->sge.ctrlq[i].q);
+}
+
+static void sync_txq_pidx(struct adapter *adap, struct sge_txq *q)
+{
+ u16 hw_pidx, hw_cidx;
+ int ret;
+
+ spin_lock_bh(&q->db_lock);
+ ret = read_eq_indices(adap, (u16)q->cntxt_id, &hw_pidx, &hw_cidx);
+ if (ret)
+ goto out;
+ if (q->db_pidx != hw_pidx) {
+ u16 delta;
+
+ if (q->db_pidx >= hw_pidx)
+ delta = q->db_pidx - hw_pidx;
+ else
+ delta = q->size - hw_pidx + q->db_pidx;
+ wmb();
+ t4_write_reg(adap, MYPF_REG(A_SGE_PF_KDOORBELL),
+ V_QID(q->cntxt_id) | V_PIDX(delta));
+ }
+out:
+ q->db_disabled = 0;
+ spin_unlock_bh(&q->db_lock);
+ if (ret)
+ CH_WARN(adap, "DB drop recovery failed.\n");
+}
+static void recover_all_queues(struct adapter *adap)
+{
+ int i;
+
+ for_each_ethrxq(&adap->sge, i)
+ sync_txq_pidx(adap, &adap->sge.ethtxq[i].q);
+ for_each_ofldrxq(&adap->sge, i)
+ sync_txq_pidx(adap, &adap->sge.ofldtxq[i].q);
+ for_each_port(adap, i)
+ sync_txq_pidx(adap, &adap->sge.ctrlq[i].q);
+}
+
static void notify_rdma_uld(struct adapter *adap, enum cxgb4_control cmd)
{
mutex_lock(&uld_mutex);
@@ -2468,55 +2612,41 @@
static void process_db_full(struct work_struct *work)
{
struct adapter *adap;
- static int delay = 1000;
- u32 v;
adap = container_of(work, struct adapter, db_full_task);
-
- /* stop LLD queues */
-
notify_rdma_uld(adap, CXGB4_CONTROL_DB_FULL);
- do {
- set_current_state(TASK_UNINTERRUPTIBLE);
- schedule_timeout(usecs_to_jiffies(delay));
- v = t4_read_reg(adap, A_SGE_DBFIFO_STATUS);
- if (G_LP_COUNT(v) == 0 && G_HP_COUNT(v) == 0)
- break;
- } while (1);
+ drain_db_fifo(adap, dbfifo_drain_delay);
+ t4_set_reg_field(adap, A_SGE_INT_ENABLE3,
+ F_DBFIFO_HP_INT | F_DBFIFO_LP_INT,
+ F_DBFIFO_HP_INT | F_DBFIFO_LP_INT);
notify_rdma_uld(adap, CXGB4_CONTROL_DB_EMPTY);
-
-
- /*
- * The more we get db full interrupts, the more we'll delay
- * in re-enabling db rings on queues, capped off at 200ms.
- */
- delay = min(delay << 1, 200000);
-
- /* resume LLD queues */
}
static void process_db_drop(struct work_struct *work)
{
struct adapter *adap;
+
adap = container_of(work, struct adapter, db_drop_task);
-
- /*
- * sync the PIDX values in HW and SW for LLD queues.
- */
-
+ t4_set_reg_field(adap, A_SGE_DOORBELL_CONTROL, F_DROPPED_DB, 0);
+ disable_dbs(adap);
notify_rdma_uld(adap, CXGB4_CONTROL_DB_DROP);
+ drain_db_fifo(adap, 1);
+ recover_all_queues(adap);
+ enable_dbs(adap);
}
void t4_db_full(struct adapter *adap)
{
- schedule_work(&adap->db_full_task);
+ t4_set_reg_field(adap, A_SGE_INT_ENABLE3,
+ F_DBFIFO_HP_INT | F_DBFIFO_LP_INT, 0);
+ queue_work(workq, &adap->db_full_task);
}
void t4_db_dropped(struct adapter *adap)
{
- schedule_work(&adap->db_drop_task);
+ queue_work(workq, &adap->db_drop_task);
}
static void uld_attach(struct adapter *adap, unsigned int uld)
@@ -2552,6 +2682,7 @@
lli.gts_reg = adap->regs + MYPF_REG(SGE_PF_GTS);
lli.db_reg = adap->regs + MYPF_REG(SGE_PF_KDOORBELL);
lli.fw_vers = adap->params.fw_vers;
+ lli.dbfifo_int_thresh = dbfifo_int_thresh;
handle = ulds[uld].add(&lli);
if (IS_ERR(handle)) {
@@ -3668,6 +3799,7 @@
adapter->pdev = pdev;
adapter->pdev_dev = &pdev->dev;
+ adapter->mbox = func;
adapter->fn = func;
adapter->msg_enable = dflt_msg_enable;
memset(adapter->chan_map, 0xff, sizeof(adapter->chan_map));
@@ -3865,6 +3997,10 @@
{
int ret;
+ workq = create_singlethread_workqueue("cxgb4");
+ if (!workq)
+ return -ENOMEM;
+
/* Debugfs support is optional, just warn if this fails */
cxgb4_debugfs_root = debugfs_create_dir(KBUILD_MODNAME, NULL);
if (!cxgb4_debugfs_root)
@@ -3880,6 +4016,8 @@
{
pci_unregister_driver(&cxgb4_driver);
debugfs_remove(cxgb4_debugfs_root); /* NULL ok */
+ flush_workqueue(workq);
+ destroy_workqueue(workq);
}
module_init(cxgb4_init_module);
diff --git a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h
index 5cc2f27..d79980c 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.h
@@ -218,6 +218,7 @@
unsigned short ucq_density; /* # of user CQs/page */
void __iomem *gts_reg; /* address of GTS register */
void __iomem *db_reg; /* address of kernel doorbell */
+ int dbfifo_int_thresh; /* doorbell fifo int threshold */
};
struct cxgb4_uld_info {
@@ -226,6 +227,7 @@
int (*rx_handler)(void *handle, const __be64 *rsp,
const struct pkt_gl *gl);
int (*state_change)(void *handle, enum cxgb4_state new_state);
+ int (*control)(void *handle, enum cxgb4_control control, ...);
};
int cxgb4_register_uld(enum cxgb4_uld type, const struct cxgb4_uld_info *p);
@@ -243,4 +245,6 @@
const unsigned int *pgsz_order);
struct sk_buff *cxgb4_pktgl_to_skb(const struct pkt_gl *gl,
unsigned int skb_len, unsigned int pull_len);
+int cxgb4_sync_txq_pidx(struct net_device *dev, u16 qid, u16 pidx, u16 size);
+int cxgb4_flush_eq_cache(struct net_device *dev);
#endif /* !__CXGB4_OFLD_H */
diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index 234c157..e111d97 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -767,8 +767,13 @@
static inline void ring_tx_db(struct adapter *adap, struct sge_txq *q, int n)
{
wmb(); /* write descriptors before telling HW */
- t4_write_reg(adap, MYPF_REG(SGE_PF_KDOORBELL),
- QID(q->cntxt_id) | PIDX(n));
+ spin_lock(&q->db_lock);
+ if (!q->db_disabled) {
+ t4_write_reg(adap, MYPF_REG(A_SGE_PF_KDOORBELL),
+ V_QID(q->cntxt_id) | V_PIDX(n));
+ }
+ q->db_pidx = q->pidx;
+ spin_unlock(&q->db_lock);
}
/**
@@ -2081,6 +2086,7 @@
q->stops = q->restarts = 0;
q->stat = (void *)&q->desc[q->size];
q->cntxt_id = id;
+ spin_lock_init(&q->db_lock);
adap->sge.egr_map[id - adap->sge.egr_start] = q;
}
@@ -2415,9 +2421,15 @@
RXPKTCPLMODE |
(STAT_LEN == 128 ? EGRSTATUSPAGESIZE : 0));
+ /*
+ * Set up to drop DOORBELL writes when the DOORBELL FIFO overflows
+ * and generate an interrupt when this occurs so we can recover.
+ */
t4_set_reg_field(adap, A_SGE_DBFIFO_STATUS,
- V_HP_INT_THRESH(5) | V_LP_INT_THRESH(5),
- V_HP_INT_THRESH(5) | V_LP_INT_THRESH(5));
+ V_HP_INT_THRESH(M_HP_INT_THRESH) |
+ V_LP_INT_THRESH(M_LP_INT_THRESH),
+ V_HP_INT_THRESH(dbfifo_int_thresh) |
+ V_LP_INT_THRESH(dbfifo_int_thresh));
t4_set_reg_field(adap, A_SGE_DOORBELL_CONTROL, F_ENABLE_DROP,
F_ENABLE_DROP);
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_regs.h b/drivers/net/ethernet/chelsio/cxgb4/t4_regs.h
index 0adc5bc..111fc32 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_regs.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_regs.h
@@ -190,6 +190,59 @@
#define SGE_DEBUG_DATA_LOW 0x10d4
#define SGE_INGRESS_QUEUES_PER_PAGE_PF 0x10f4
+#define S_LP_INT_THRESH 12
+#define V_LP_INT_THRESH(x) ((x) << S_LP_INT_THRESH)
+#define S_HP_INT_THRESH 28
+#define V_HP_INT_THRESH(x) ((x) << S_HP_INT_THRESH)
+#define A_SGE_DBFIFO_STATUS 0x10a4
+
+#define S_ENABLE_DROP 13
+#define V_ENABLE_DROP(x) ((x) << S_ENABLE_DROP)
+#define F_ENABLE_DROP V_ENABLE_DROP(1U)
+#define A_SGE_DOORBELL_CONTROL 0x10a8
+
+#define A_SGE_CTXT_CMD 0x11fc
+#define A_SGE_DBQ_CTXT_BADDR 0x1084
+
+#define A_SGE_PF_KDOORBELL 0x0
+
+#define S_QID 15
+#define V_QID(x) ((x) << S_QID)
+
+#define S_PIDX 0
+#define V_PIDX(x) ((x) << S_PIDX)
+
+#define M_LP_COUNT 0x7ffU
+#define S_LP_COUNT 0
+#define G_LP_COUNT(x) (((x) >> S_LP_COUNT) & M_LP_COUNT)
+
+#define M_HP_COUNT 0x7ffU
+#define S_HP_COUNT 16
+#define G_HP_COUNT(x) (((x) >> S_HP_COUNT) & M_HP_COUNT)
+
+#define A_SGE_INT_ENABLE3 0x1040
+
+#define S_DBFIFO_HP_INT 8
+#define V_DBFIFO_HP_INT(x) ((x) << S_DBFIFO_HP_INT)
+#define F_DBFIFO_HP_INT V_DBFIFO_HP_INT(1U)
+
+#define S_DBFIFO_LP_INT 7
+#define V_DBFIFO_LP_INT(x) ((x) << S_DBFIFO_LP_INT)
+#define F_DBFIFO_LP_INT V_DBFIFO_LP_INT(1U)
+
+#define S_DROPPED_DB 0
+#define V_DROPPED_DB(x) ((x) << S_DROPPED_DB)
+#define F_DROPPED_DB V_DROPPED_DB(1U)
+
+#define S_ERR_DROPPED_DB 18
+#define V_ERR_DROPPED_DB(x) ((x) << S_ERR_DROPPED_DB)
+#define F_ERR_DROPPED_DB V_ERR_DROPPED_DB(1U)
+
+#define A_PCIE_MEM_ACCESS_OFFSET 0x306c
+
+#define M_HP_INT_THRESH 0xfU
+#define M_LP_INT_THRESH 0xfU
+
#define PCIE_PF_CLI 0x44
#define PCIE_INT_CAUSE 0x3004
#define UNXSPLCPLERR 0x20000000U
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h b/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h
index edcfd7e..ad53f79 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h
@@ -1620,4 +1620,19 @@
#define FW_HDR_FW_VER_MINOR_GET(x) (((x) >> 16) & 0xff)
#define FW_HDR_FW_VER_MICRO_GET(x) (((x) >> 8) & 0xff)
#define FW_HDR_FW_VER_BUILD_GET(x) (((x) >> 0) & 0xff)
+
+#define S_FW_CMD_OP 24
+#define V_FW_CMD_OP(x) ((x) << S_FW_CMD_OP)
+
+#define S_FW_CMD_REQUEST 23
+#define V_FW_CMD_REQUEST(x) ((x) << S_FW_CMD_REQUEST)
+#define F_FW_CMD_REQUEST V_FW_CMD_REQUEST(1U)
+
+#define S_FW_CMD_WRITE 21
+#define V_FW_CMD_WRITE(x) ((x) << S_FW_CMD_WRITE)
+#define F_FW_CMD_WRITE V_FW_CMD_WRITE(1U)
+
+#define S_FW_LDST_CMD_ADDRSPACE 0
+#define V_FW_LDST_CMD_ADDRSPACE(x) ((x) << S_FW_LDST_CMD_ADDRSPACE)
+
#endif /* _T4FW_INTERFACE_H_ */