@@ -18,4 +18,5 @@ fbnic-y := fbnic_devlink.o \
fbnic_phylink.o \
fbnic_rpc.o \
fbnic_tlv.o \
- fbnic_txrx.o
+ fbnic_txrx.o \
+ fbnic_time.o
@@ -6,6 +6,7 @@
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/ptp_clock_kernel.h>
#include <linux/types.h>
#include <linux/workqueue.h>
@@ -49,6 +50,16 @@ struct fbnic_dev {
/* Number of TCQs/RCQs available on hardware */
u16 max_num_queues;
+ /* Lock protecting writes to @time_high, @time_offset of fbnic_netdev,
+ * and the HW time CSR machinery.
+ */
+ spinlock_t time_lock;
+ /* Externally accessible PTP clock, may be NULL */
+ struct ptp_clock *ptp;
+ struct ptp_clock_info ptp_info;
+ /* Last @time_high refresh time in jiffies (to catch stalls) */
+ unsigned long last_read;
+
/* Local copy of hardware statistics */
struct fbnic_hw_stats hw_stats;
};
@@ -413,6 +413,44 @@ enum {
#define FBNIC_TMI_DROP_CTRL 0x04401 /* 0x11004 */
#define FBNIC_TMI_DROP_CTRL_EN CSR_BIT(0)
#define FBNIC_CSR_END_TMI 0x0443f /* CSR section delimiter */
+
+/* Precision Time Protocol Registers */
+#define FBNIC_CSR_START_PTP 0x04800 /* CSR section delimiter */
+#define FBNIC_PTP_REG_BASE 0x04800 /* 0x12000 */
+
+#define FBNIC_PTP_CTRL 0x04800 /* 0x12000 */
+#define FBNIC_PTP_CTRL_EN CSR_BIT(0)
+#define FBNIC_PTP_CTRL_MONO_EN CSR_BIT(4)
+#define FBNIC_PTP_CTRL_TQS_OUT_EN CSR_BIT(8)
+#define FBNIC_PTP_CTRL_MAC_OUT_IVAL CSR_GENMASK(16, 12)
+#define FBNIC_PTP_CTRL_TICK_IVAL CSR_GENMASK(23, 20)
+
+#define FBNIC_PTP_ADJUST 0x04801 /* 0x12004 */
+#define FBNIC_PTP_ADJUST_INIT CSR_BIT(0)
+#define FBNIC_PTP_ADJUST_SUB_NUDGE CSR_BIT(8)
+#define FBNIC_PTP_ADJUST_ADD_NUDGE CSR_BIT(16)
+#define FBNIC_PTP_ADJUST_ADDEND_SET CSR_BIT(24)
+
+#define FBNIC_PTP_INIT_HI 0x04802 /* 0x12008 */
+#define FBNIC_PTP_INIT_LO 0x04803 /* 0x1200c */
+
+#define FBNIC_PTP_NUDGE_NS 0x04804 /* 0x12010 */
+#define FBNIC_PTP_NUDGE_SUBNS 0x04805 /* 0x12014 */
+
+#define FBNIC_PTP_ADD_VAL_NS 0x04806 /* 0x12018 */
+#define FBNIC_PTP_ADD_VAL_NS_MASK CSR_GENMASK(15, 0)
+#define FBNIC_PTP_ADD_VAL_SUBNS 0x04807 /* 0x1201c */
+
+#define FBNIC_PTP_CTR_VAL_HI 0x04808 /* 0x12020 */
+#define FBNIC_PTP_CTR_VAL_LO 0x04809 /* 0x12024 */
+
+#define FBNIC_PTP_MONO_PTP_CTR_HI 0x0480a /* 0x12028 */
+#define FBNIC_PTP_MONO_PTP_CTR_LO 0x0480b /* 0x1202c */
+
+#define FBNIC_PTP_CDC_FIFO_STATUS 0x0480c /* 0x12030 */
+#define FBNIC_PTP_SPARE 0x0480d /* 0x12034 */
+#define FBNIC_CSR_END_PTP 0x0480d /* CSR section delimiter */
+
/* Rx Buffer Registers */
#define FBNIC_CSR_START_RXB 0x08000 /* CSR section delimiter */
enum {
@@ -42,18 +42,24 @@ int __fbnic_open(struct fbnic_net *fbn)
goto free_resources;
}
- err = fbnic_fw_init_heartbeat(fbd, false);
+ err = fbnic_time_start(fbn);
if (err)
goto release_ownership;
+ err = fbnic_fw_init_heartbeat(fbd, false);
+ if (err)
+ goto time_stop;
+
err = fbnic_pcs_irq_enable(fbd);
if (err)
- goto release_ownership;
+ goto time_stop;
/* Pull the BMC config and initialize the RPC */
fbnic_bmc_rpc_init(fbd);
fbnic_rss_reinit(fbd, fbn);
return 0;
+time_stop:
+ fbnic_time_stop(fbn);
release_ownership:
fbnic_fw_xmit_ownership_msg(fbn->fbd, false);
free_resources:
@@ -82,6 +88,7 @@ static int fbnic_stop(struct net_device *netdev)
fbnic_down(fbn);
fbnic_pcs_irq_disable(fbn->fbd);
+ fbnic_time_stop(fbn);
fbnic_fw_xmit_ownership_msg(fbn->fbd, false);
fbnic_free_resources(fbn);
@@ -33,6 +33,15 @@ struct fbnic_net {
u8 fec;
u8 link_mode;
+ /* Cached top bits of the HW time counter for 40b -> 64b conversion */
+ u32 time_high;
+ /* Protect readers of @time_offset, writers take @time_lock. */
+ struct u64_stats_sync time_seq;
+ /* Offset in ns between free running NIC PHC and time set via PTP
+ * clock callbacks
+ */
+ s64 time_offset;
+
u16 num_tx_queues;
u16 num_rx_queues;
@@ -60,6 +69,12 @@ void fbnic_reset_queues(struct fbnic_net *fbn,
unsigned int tx, unsigned int rx);
void fbnic_set_ethtool_ops(struct net_device *dev);
+int fbnic_ptp_setup(struct fbnic_dev *fbd);
+void fbnic_ptp_destroy(struct fbnic_dev *fbd);
+void fbnic_time_init(struct fbnic_net *fbn);
+int fbnic_time_start(struct fbnic_net *fbn);
+void fbnic_time_stop(struct fbnic_net *fbn);
+
void __fbnic_set_rx_mode(struct net_device *netdev);
void fbnic_clear_rx_mode(struct net_device *netdev);
@@ -300,14 +300,20 @@ static int fbnic_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
goto init_failure_mode;
}
+ err = fbnic_ptp_setup(fbd);
+ if (err)
+ goto ifm_free_netdev;
+
err = fbnic_netdev_register(netdev);
if (err) {
dev_err(&pdev->dev, "Netdev registration failed: %d\n", err);
- goto ifm_free_netdev;
+ goto ifm_destroy_ptp;
}
return 0;
+ifm_destroy_ptp:
+ fbnic_ptp_destroy(fbd);
ifm_free_netdev:
fbnic_netdev_free(fbd);
init_failure_mode:
@@ -342,6 +348,7 @@ static void fbnic_remove(struct pci_dev *pdev)
fbnic_netdev_unregister(netdev);
cancel_delayed_work_sync(&fbd->service_task);
+ fbnic_ptp_destroy(fbd);
fbnic_netdev_free(fbd);
}
new file mode 100644
@@ -0,0 +1,309 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) Meta Platforms, Inc. and affiliates. */
+
+#include <linux/bitfield.h>
+#include <linux/jiffies.h>
+#include <linux/limits.h>
+#include <linux/ptp_clock_kernel.h>
+#include <linux/timer.h>
+
+#include "fbnic.h"
+#include "fbnic_csr.h"
+#include "fbnic_netdev.h"
+
+/* FBNIC timing & PTP implementation
+ * Datapath uses truncated 40b timestamps for scheduling and event reporting.
+ * We need to promote those to full 64b, hence we periodically cache the top
+ * 32bit of the HW time counter. Since this makes our time reporting non-atomic
+ * we leave the HW clock free running and adjust time offsets in SW as needed.
+ * Time offset is 64bit - we need a seq counter for 32bit machines.
+ * Time offset and the cache of top bits are independent so we don't need
+ * a coherent snapshot of both - READ_ONCE()/WRITE_ONCE() + writer side lock
+ * are enough.
+ *
+ * TBD: alias u64_stats_sync & co. with some more appropriate names upstream.
+ */
+
+/* Period of refresh of top bits of timestamp, give ourselves a 8x margin.
+ * This should translate to once a minute.
+ * The use of nsecs_to_jiffies() should be safe for a <=40b nsec value.
+ */
+#define FBNIC_TS_HIGH_REFRESH_JIF nsecs_to_jiffies((1ULL << 40) / 16)
+
+static struct fbnic_dev *fbnic_from_ptp_info(struct ptp_clock_info *ptp)
+{
+ return container_of(ptp, struct fbnic_dev, ptp_info);
+}
+
+/* This function is "slow" because we could try guessing which high part
+ * is correct based on low instead of re-reading, and skip reading @hi
+ * twice altogether if @lo is far enough from 0.
+ */
+static u64 __fbnic_time_get_slow(struct fbnic_dev *fbd)
+{
+ u32 hi, lo;
+
+ lockdep_assert_held(&fbd->time_lock);
+
+ do {
+ hi = fbnic_rd32(fbd, FBNIC_PTP_CTR_VAL_HI);
+ lo = fbnic_rd32(fbd, FBNIC_PTP_CTR_VAL_LO);
+ } while (hi != fbnic_rd32(fbd, FBNIC_PTP_CTR_VAL_HI));
+
+ return (u64)hi << 32 | lo;
+}
+
+static void __fbnic_time_set_addend(struct fbnic_dev *fbd, u64 addend)
+{
+ lockdep_assert_held(&fbd->time_lock);
+
+ fbnic_wr32(fbd, FBNIC_PTP_ADD_VAL_NS,
+ FIELD_PREP(FBNIC_PTP_ADD_VAL_NS_MASK, addend >> 32));
+ fbnic_wr32(fbd, FBNIC_PTP_ADD_VAL_SUBNS, (u32)addend);
+}
+
+static void fbnic_ptp_fresh_check(struct fbnic_dev *fbd)
+{
+ if (time_is_after_jiffies(fbd->last_read +
+ FBNIC_TS_HIGH_REFRESH_JIF * 3 / 2))
+ return;
+
+ dev_warn(fbd->dev, "NIC timestamp refresh stall, delayed by %lu sec\n",
+ (jiffies - fbd->last_read - FBNIC_TS_HIGH_REFRESH_JIF) / HZ);
+}
+
+static void fbnic_ptp_refresh_time(struct fbnic_dev *fbd, struct fbnic_net *fbn)
+{
+ unsigned long flags;
+ u32 hi;
+
+ spin_lock_irqsave(&fbd->time_lock, flags);
+ hi = fbnic_rd32(fbn->fbd, FBNIC_PTP_CTR_VAL_HI);
+ if (!fbnic_present(fbd))
+ goto out; /* Don't bother handling, reset is pending */
+ WRITE_ONCE(fbn->time_high, hi);
+ fbd->last_read = jiffies;
+ out:
+ spin_unlock_irqrestore(&fbd->time_lock, flags);
+}
+
+static long fbnic_ptp_do_aux_work(struct ptp_clock_info *ptp)
+{
+ struct fbnic_dev *fbd = fbnic_from_ptp_info(ptp);
+ struct fbnic_net *fbn;
+
+ fbn = netdev_priv(fbd->netdev);
+
+ fbnic_ptp_fresh_check(fbd);
+ fbnic_ptp_refresh_time(fbd, fbn);
+
+ return FBNIC_TS_HIGH_REFRESH_JIF;
+}
+
+static int fbnic_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
+{
+ int scale = 16; /* scaled_ppm has 16 fractional places */
+ struct fbnic_dev *fbd = fbnic_from_ptp_info(ptp);
+ u64 scaled_delta, dclk_period;
+ unsigned long flags;
+ s64 delta;
+ int sgn;
+
+ sgn = scaled_ppm >= 0 ? 1 : -1;
+ scaled_ppm *= sgn;
+
+ /* d_clock is 600 MHz; which in Q16.32 fixed point ns is: */
+ dclk_period = (((u64)1000000000) << 32) / FBNIC_CLOCK_FREQ;
+
+ while (scaled_ppm > U64_MAX / dclk_period) {
+ scaled_ppm >>= 1;
+ scale--;
+ }
+
+ scaled_delta = (u64)scaled_ppm * dclk_period;
+ delta = div_u64(scaled_delta, 1000 * 1000) >> scale;
+ delta *= sgn;
+
+ spin_lock_irqsave(&fbd->time_lock, flags);
+ __fbnic_time_set_addend(fbd, dclk_period + delta);
+ fbnic_wr32(fbd, FBNIC_PTP_ADJUST, FBNIC_PTP_ADJUST_ADDEND_SET);
+
+ /* Flush, make sure FBNIC_PTP_ADD_VAL_* is stable for at least 4 clks */
+ fbnic_rd32(fbd, FBNIC_PTP_SPARE);
+ spin_unlock_irqrestore(&fbd->time_lock, flags);
+
+ return fbnic_present(fbd) ? 0 : -EIO;
+}
+
+static int fbnic_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+ struct fbnic_dev *fbd = fbnic_from_ptp_info(ptp);
+ struct fbnic_net *fbn;
+ unsigned long flags;
+
+ fbn = netdev_priv(fbd->netdev);
+
+ spin_lock_irqsave(&fbd->time_lock, flags);
+ u64_stats_update_begin(&fbn->time_seq);
+ WRITE_ONCE(fbn->time_offset, READ_ONCE(fbn->time_offset) + delta);
+ u64_stats_update_end(&fbn->time_seq);
+ spin_unlock_irqrestore(&fbd->time_lock, flags);
+
+ return 0;
+}
+
+static int
+fbnic_ptp_gettimex64(struct ptp_clock_info *ptp, struct timespec64 *ts,
+ struct ptp_system_timestamp *sts)
+{
+ struct fbnic_dev *fbd = fbnic_from_ptp_info(ptp);
+ struct fbnic_net *fbn;
+ unsigned long flags;
+ u64 time_ns;
+ u32 hi, lo;
+
+ fbn = netdev_priv(fbd->netdev);
+
+ spin_lock_irqsave(&fbd->time_lock, flags);
+
+ do {
+ hi = fbnic_rd32(fbd, FBNIC_PTP_CTR_VAL_HI);
+ ptp_read_system_prets(sts);
+ lo = fbnic_rd32(fbd, FBNIC_PTP_CTR_VAL_LO);
+ ptp_read_system_postts(sts);
+ /* Similarly to comment above __fbnic_time_get_slow()
+ * - this can be optimized if needed.
+ */
+ } while (hi != fbnic_rd32(fbd, FBNIC_PTP_CTR_VAL_HI));
+
+ time_ns = ((u64)hi << 32 | lo) + fbn->time_offset;
+ spin_unlock_irqrestore(&fbd->time_lock, flags);
+
+ if (!fbnic_present(fbd))
+ return -EIO;
+
+ *ts = ns_to_timespec64(time_ns);
+
+ return 0;
+}
+
+static int
+fbnic_ptp_settime64(struct ptp_clock_info *ptp, const struct timespec64 *ts)
+{
+ struct fbnic_dev *fbd = fbnic_from_ptp_info(ptp);
+ struct fbnic_net *fbn;
+ unsigned long flags;
+ u64 dev_ns, host_ns;
+ int ret;
+
+ fbn = netdev_priv(fbd->netdev);
+
+ host_ns = timespec64_to_ns(ts);
+
+ spin_lock_irqsave(&fbd->time_lock, flags);
+
+ dev_ns = __fbnic_time_get_slow(fbd);
+
+ if (fbnic_present(fbd)) {
+ u64_stats_update_begin(&fbn->time_seq);
+ WRITE_ONCE(fbn->time_offset, host_ns - dev_ns);
+ u64_stats_update_end(&fbn->time_seq);
+ ret = 0;
+ } else {
+ ret = -EIO;
+ }
+ spin_unlock_irqrestore(&fbd->time_lock, flags);
+
+ return ret;
+}
+
+static const struct ptp_clock_info fbnic_ptp_info = {
+ .owner = THIS_MODULE,
+ /* 1,000,000,000 - 1 PPB to ensure increment is positive
+ * after max negative adjustment.
+ */
+ .max_adj = 999999999,
+ .do_aux_work = fbnic_ptp_do_aux_work,
+ .adjfine = fbnic_ptp_adjfine,
+ .adjtime = fbnic_ptp_adjtime,
+ .gettimex64 = fbnic_ptp_gettimex64,
+ .settime64 = fbnic_ptp_settime64,
+};
+
+static void fbnic_ptp_reset(struct fbnic_dev *fbd)
+{
+ struct fbnic_net *fbn = netdev_priv(fbd->netdev);
+ u64 dclk_period;
+
+ fbnic_wr32(fbd, FBNIC_PTP_CTRL,
+ FBNIC_PTP_CTRL_EN |
+ FIELD_PREP(FBNIC_PTP_CTRL_TICK_IVAL, 1));
+
+ /* d_clock is 600 MHz; which in Q16.32 fixed point ns is: */
+ dclk_period = (((u64)1000000000) << 32) / FBNIC_CLOCK_FREQ;
+
+ __fbnic_time_set_addend(fbd, dclk_period);
+
+ fbnic_wr32(fbd, FBNIC_PTP_INIT_HI, 0);
+ fbnic_wr32(fbd, FBNIC_PTP_INIT_LO, 0);
+
+ fbnic_wr32(fbd, FBNIC_PTP_ADJUST, FBNIC_PTP_ADJUST_INIT);
+
+ fbnic_wr32(fbd, FBNIC_PTP_CTRL,
+ FBNIC_PTP_CTRL_EN |
+ FBNIC_PTP_CTRL_TQS_OUT_EN |
+ FIELD_PREP(FBNIC_PTP_CTRL_MAC_OUT_IVAL, 3) |
+ FIELD_PREP(FBNIC_PTP_CTRL_TICK_IVAL, 1));
+
+ fbnic_rd32(fbd, FBNIC_PTP_SPARE);
+
+ fbn->time_offset = 0;
+ fbn->time_high = 0;
+}
+
+void fbnic_time_init(struct fbnic_net *fbn)
+{
+ u64_stats_init(&fbn->time_seq);
+}
+
+int fbnic_time_start(struct fbnic_net *fbn)
+{
+ fbnic_ptp_refresh_time(fbn->fbd, fbn);
+ /* Assume that fbnic_ptp_do_aux_work() will never be called if not
+ * scheduled here
+ */
+ return ptp_schedule_worker(fbn->fbd->ptp, FBNIC_TS_HIGH_REFRESH_JIF);
+}
+
+void fbnic_time_stop(struct fbnic_net *fbn)
+{
+ ptp_cancel_worker_sync(fbn->fbd->ptp);
+ fbnic_ptp_fresh_check(fbn->fbd);
+}
+
+int fbnic_ptp_setup(struct fbnic_dev *fbd)
+{
+ struct device *dev = fbd->dev;
+ unsigned long flags;
+
+ spin_lock_init(&fbd->time_lock);
+
+ spin_lock_irqsave(&fbd->time_lock, flags); /* Appease lockdep */
+ fbnic_ptp_reset(fbd);
+ spin_unlock_irqrestore(&fbd->time_lock, flags);
+
+ memcpy(&fbd->ptp_info, &fbnic_ptp_info, sizeof(fbnic_ptp_info));
+
+ fbd->ptp = ptp_clock_register(&fbd->ptp_info, dev);
+ if (IS_ERR(fbd->ptp))
+ dev_err(dev, "Failed to register PTP: %pe\n", fbd->ptp);
+
+ return PTR_ERR_OR_ZERO(fbd->ptp);
+}
+
+void fbnic_ptp_destroy(struct fbnic_dev *fbd)
+{
+ if (!fbd->ptp)
+ return;
+ ptp_clock_unregister(fbd->ptp);
+}
Create PHC device and provide callbacks needed for ptp_clock device. Signed-off-by: Vadim Fedorenko <vadfed@meta.com> --- drivers/net/ethernet/meta/fbnic/Makefile | 3 +- drivers/net/ethernet/meta/fbnic/fbnic.h | 11 + drivers/net/ethernet/meta/fbnic/fbnic_csr.h | 38 +++ .../net/ethernet/meta/fbnic/fbnic_netdev.c | 11 +- .../net/ethernet/meta/fbnic/fbnic_netdev.h | 15 + drivers/net/ethernet/meta/fbnic/fbnic_pci.c | 9 +- drivers/net/ethernet/meta/fbnic/fbnic_time.c | 309 ++++++++++++++++++ 7 files changed, 392 insertions(+), 4 deletions(-) create mode 100644 drivers/net/ethernet/meta/fbnic/fbnic_time.c