igb: offer a PTP Hardware Clock instead of the timecompare method
This commit removes the legacy timecompare code from the igb driver and
offers a tunable PHC instead.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/Kconfig b/drivers/net/ethernet/intel/Kconfig
index 7621316..90142aa 100644
--- a/drivers/net/ethernet/intel/Kconfig
+++ b/drivers/net/ethernet/intel/Kconfig
@@ -120,6 +120,17 @@
driver. DCA is a method for warming the CPU cache before data
is used, with the intent of lessening the impact of cache misses.
+config IGB_PTP
+ bool "PTP Hardware Clock (PHC)"
+ default y
+ depends on IGB && PTP_1588_CLOCK
+ ---help---
+ Say Y here if you want to use PTP Hardware Clock (PHC) in the
+ driver. Only the basic clock operations have been implemented.
+
+ Every timestamp and clock read operations must consult the
+ overflow counter to form a correct time value.
+
config IGBVF
tristate "Intel(R) 82576 Virtual Function Ethernet support"
depends on PCI
diff --git a/drivers/net/ethernet/intel/igb/Makefile b/drivers/net/ethernet/intel/igb/Makefile
index 6565c46..4bd16e2 100644
--- a/drivers/net/ethernet/intel/igb/Makefile
+++ b/drivers/net/ethernet/intel/igb/Makefile
@@ -35,3 +35,4 @@
igb-objs := igb_main.o igb_ethtool.o e1000_82575.o \
e1000_mac.o e1000_nvm.o e1000_phy.o e1000_mbx.o
+igb-$(CONFIG_IGB_PTP) += igb_ptp.o
diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h
index f0265e8..3758ad2 100644
--- a/drivers/net/ethernet/intel/igb/igb.h
+++ b/drivers/net/ethernet/intel/igb/igb.h
@@ -35,7 +35,6 @@
#include "e1000_82575.h"
#include <linux/clocksource.h>
-#include <linux/timecompare.h>
#include <linux/net_tstamp.h>
#include <linux/ptp_clock_kernel.h>
#include <linux/bitops.h>
@@ -329,9 +328,6 @@
/* OS defined structs */
struct pci_dev *pdev;
- struct cyclecounter cycles;
- struct timecounter clock;
- struct timecompare compare;
struct hwtstamp_config hwtstamp_config;
spinlock_t stats64_lock;
@@ -386,7 +382,6 @@
#define IGB_DMCTLX_DCFLUSH_DIS 0x80000000 /* Disable DMA Coal Flush */
#define IGB_82576_TSYNC_SHIFT 19
-#define IGB_82580_TSYNC_SHIFT 24
#define IGB_TS_HDR_LEN 16
enum e1000_state_t {
__IGB_TESTING,
@@ -422,7 +417,15 @@
extern bool igb_has_link(struct igb_adapter *adapter);
extern void igb_set_ethtool_ops(struct net_device *);
extern void igb_power_up_link(struct igb_adapter *);
+#ifdef CONFIG_IGB_PTP
+extern void igb_ptp_init(struct igb_adapter *adapter);
+extern void igb_ptp_remove(struct igb_adapter *adapter);
+extern void igb_systim_to_hwtstamp(struct igb_adapter *adapter,
+ struct skb_shared_hwtstamps *hwtstamps,
+ u64 systim);
+
+#endif
static inline s32 igb_reset_phy(struct e1000_hw *hw)
{
if (hw->phy.ops.reset)
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 5ec3159..f022ff7 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -114,7 +114,6 @@
static void igb_setup_mrqc(struct igb_adapter *);
static int igb_probe(struct pci_dev *, const struct pci_device_id *);
static void __devexit igb_remove(struct pci_dev *pdev);
-static void igb_init_hw_timer(struct igb_adapter *adapter);
static int igb_sw_init(struct igb_adapter *);
static int igb_open(struct net_device *);
static int igb_close(struct net_device *);
@@ -565,33 +564,6 @@
return;
}
-
-/**
- * igb_read_clock - read raw cycle counter (to be used by time counter)
- */
-static cycle_t igb_read_clock(const struct cyclecounter *tc)
-{
- struct igb_adapter *adapter =
- container_of(tc, struct igb_adapter, cycles);
- struct e1000_hw *hw = &adapter->hw;
- u64 stamp = 0;
- int shift = 0;
-
- /*
- * The timestamp latches on lowest register read. For the 82580
- * the lowest register is SYSTIMR instead of SYSTIML. However we never
- * adjusted TIMINCA so SYSTIMR will just read as all 0s so ignore it.
- */
- if (hw->mac.type >= e1000_82580) {
- stamp = rd32(E1000_SYSTIMR) >> 8;
- shift = IGB_82580_TSYNC_SHIFT;
- }
-
- stamp |= (u64)rd32(E1000_SYSTIML) << shift;
- stamp |= (u64)rd32(E1000_SYSTIMH) << (shift + 32);
- return stamp;
-}
-
/**
* igb_get_hw_dev - return device
* used by hardware layer to print debugging information
@@ -2110,9 +2082,11 @@
}
#endif
+#ifdef CONFIG_IGB_PTP
/* do hw tstamp init after resetting */
- igb_init_hw_timer(adapter);
+ igb_ptp_init(adapter);
+#endif
dev_info(&pdev->dev, "Intel(R) Gigabit Ethernet Network Connection\n");
/* print bus type/speed/width info */
dev_info(&pdev->dev, "%s: (PCIe:%s:%s) %pM\n",
@@ -2184,7 +2158,10 @@
struct e1000_hw *hw = &adapter->hw;
pm_runtime_get_noresume(&pdev->dev);
+#ifdef CONFIG_IGB_PTP
+ igb_ptp_remove(adapter);
+#endif
/*
* The watchdog timer may be rescheduled, so explicitly
* disable watchdog from being rescheduled.
@@ -2304,112 +2281,6 @@
}
/**
- * igb_init_hw_timer - Initialize hardware timer used with IEEE 1588 timestamp
- * @adapter: board private structure to initialize
- *
- * igb_init_hw_timer initializes the function pointer and values for the hw
- * timer found in hardware.
- **/
-static void igb_init_hw_timer(struct igb_adapter *adapter)
-{
- struct e1000_hw *hw = &adapter->hw;
-
- switch (hw->mac.type) {
- case e1000_i350:
- case e1000_82580:
- memset(&adapter->cycles, 0, sizeof(adapter->cycles));
- adapter->cycles.read = igb_read_clock;
- adapter->cycles.mask = CLOCKSOURCE_MASK(64);
- adapter->cycles.mult = 1;
- /*
- * The 82580 timesync updates the system timer every 8ns by 8ns
- * and the value cannot be shifted. Instead we need to shift
- * the registers to generate a 64bit timer value. As a result
- * SYSTIMR/L/H, TXSTMPL/H, RXSTMPL/H all have to be shifted by
- * 24 in order to generate a larger value for synchronization.
- */
- adapter->cycles.shift = IGB_82580_TSYNC_SHIFT;
- /* disable system timer temporarily by setting bit 31 */
- wr32(E1000_TSAUXC, 0x80000000);
- wrfl();
-
- /* Set registers so that rollover occurs soon to test this. */
- wr32(E1000_SYSTIMR, 0x00000000);
- wr32(E1000_SYSTIML, 0x80000000);
- wr32(E1000_SYSTIMH, 0x000000FF);
- wrfl();
-
- /* enable system timer by clearing bit 31 */
- wr32(E1000_TSAUXC, 0x0);
- wrfl();
-
- timecounter_init(&adapter->clock,
- &adapter->cycles,
- ktime_to_ns(ktime_get_real()));
- /*
- * Synchronize our NIC clock against system wall clock. NIC
- * time stamp reading requires ~3us per sample, each sample
- * was pretty stable even under load => only require 10
- * samples for each offset comparison.
- */
- memset(&adapter->compare, 0, sizeof(adapter->compare));
- adapter->compare.source = &adapter->clock;
- adapter->compare.target = ktime_get_real;
- adapter->compare.num_samples = 10;
- timecompare_update(&adapter->compare, 0);
- break;
- case e1000_82576:
- /*
- * Initialize hardware timer: we keep it running just in case
- * that some program needs it later on.
- */
- memset(&adapter->cycles, 0, sizeof(adapter->cycles));
- adapter->cycles.read = igb_read_clock;
- adapter->cycles.mask = CLOCKSOURCE_MASK(64);
- adapter->cycles.mult = 1;
- /**
- * Scale the NIC clock cycle by a large factor so that
- * relatively small clock corrections can be added or
- * subtracted at each clock tick. The drawbacks of a large
- * factor are a) that the clock register overflows more quickly
- * (not such a big deal) and b) that the increment per tick has
- * to fit into 24 bits. As a result we need to use a shift of
- * 19 so we can fit a value of 16 into the TIMINCA register.
- */
- adapter->cycles.shift = IGB_82576_TSYNC_SHIFT;
- wr32(E1000_TIMINCA,
- (1 << E1000_TIMINCA_16NS_SHIFT) |
- (16 << IGB_82576_TSYNC_SHIFT));
-
- /* Set registers so that rollover occurs soon to test this. */
- wr32(E1000_SYSTIML, 0x00000000);
- wr32(E1000_SYSTIMH, 0xFF800000);
- wrfl();
-
- timecounter_init(&adapter->clock,
- &adapter->cycles,
- ktime_to_ns(ktime_get_real()));
- /*
- * Synchronize our NIC clock against system wall clock. NIC
- * time stamp reading requires ~3us per sample, each sample
- * was pretty stable even under load => only require 10
- * samples for each offset comparison.
- */
- memset(&adapter->compare, 0, sizeof(adapter->compare));
- adapter->compare.source = &adapter->clock;
- adapter->compare.target = ktime_get_real;
- adapter->compare.num_samples = 10;
- timecompare_update(&adapter->compare, 0);
- break;
- case e1000_82575:
- /* 82575 does not support timesync */
- default:
- break;
- }
-
-}
-
-/**
* igb_sw_init - Initialize general software structures (struct igb_adapter)
* @adapter: board private structure to initialize
*
@@ -5718,35 +5589,7 @@
return 0;
}
-/**
- * igb_systim_to_hwtstamp - convert system time value to hw timestamp
- * @adapter: board private structure
- * @shhwtstamps: timestamp structure to update
- * @regval: unsigned 64bit system time value.
- *
- * We need to convert the system time value stored in the RX/TXSTMP registers
- * into a hwtstamp which can be used by the upper level timestamping functions
- */
-static void igb_systim_to_hwtstamp(struct igb_adapter *adapter,
- struct skb_shared_hwtstamps *shhwtstamps,
- u64 regval)
-{
- u64 ns;
-
- /*
- * The 82580 starts with 1ns at bit 0 in RX/TXSTMPL, shift this up to
- * 24 to match clock shift we setup earlier.
- */
- if (adapter->hw.mac.type >= e1000_82580)
- regval <<= IGB_82580_TSYNC_SHIFT;
-
- ns = timecounter_cyc2time(&adapter->clock, regval);
- timecompare_update(&adapter->compare, ns);
- memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps));
- shhwtstamps->hwtstamp = ns_to_ktime(ns);
- shhwtstamps->syststamp = timecompare_transform(&adapter->compare, ns);
-}
-
+#ifdef CONFIG_IGB_PTP
/**
* igb_tx_hwtstamp - utility function which checks for TX time stamp
* @q_vector: pointer to q_vector containing needed info
@@ -5776,6 +5619,7 @@
skb_tstamp_tx(buffer_info->skb, &shhwtstamps);
}
+#endif
/**
* igb_clean_tx_irq - Reclaim resources after transmit completes
* @q_vector: pointer to q_vector containing needed info
@@ -5819,9 +5663,11 @@
total_bytes += tx_buffer->bytecount;
total_packets += tx_buffer->gso_segs;
+#ifdef CONFIG_IGB_PTP
/* retrieve hardware timestamp */
igb_tx_hwtstamp(q_vector, tx_buffer);
+#endif
/* free the skb */
dev_kfree_skb_any(tx_buffer->skb);
tx_buffer->skb = NULL;
@@ -5993,6 +5839,7 @@
skb->rxhash = le32_to_cpu(rx_desc->wb.lower.hi_dword.rss);
}
+#ifdef CONFIG_IGB_PTP
static void igb_rx_hwtstamp(struct igb_q_vector *q_vector,
union e1000_adv_rx_desc *rx_desc,
struct sk_buff *skb)
@@ -6032,6 +5879,7 @@
igb_systim_to_hwtstamp(adapter, skb_hwtstamps(skb), regval);
}
+#endif
static void igb_rx_vlan(struct igb_ring *ring,
union e1000_adv_rx_desc *rx_desc,
struct sk_buff *skb)
@@ -6142,7 +5990,9 @@
goto next_desc;
}
+#ifdef CONFIG_IGB_PTP
igb_rx_hwtstamp(q_vector, rx_desc, skb);
+#endif
igb_rx_hash(rx_ring, rx_desc, skb);
igb_rx_checksum(rx_ring, rx_desc, skb);
igb_rx_vlan(rx_ring, rx_desc, skb);
diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c
index c8254cf..c9b71c5 100644
--- a/drivers/net/ethernet/intel/igb/igb_ptp.c
+++ b/drivers/net/ethernet/intel/igb/igb_ptp.c
@@ -27,6 +27,9 @@
#define ISGN 0x80000000
/*
+ * The 82580 timesync updates the system timer every 8ns by 8ns,
+ * and this update value cannot be reprogrammed.
+ *
* Neither the 82576 nor the 82580 offer registers wide enough to hold
* nanoseconds time values for very long. For the 82580, SYSTIM always
* counts nanoseconds, but the upper 24 bits are not availible. The
@@ -38,6 +41,14 @@
* field are needed to provide the nominal 16 nanosecond period,
* leaving 19 bits for fractional nanoseconds.
*
+ * We scale the NIC clock cycle by a large factor so that relatively
+ * small clock corrections can be added or subtracted at each clock
+ * tick. The drawbacks of a large factor are a) that the clock
+ * register overflows more quickly (not such a big deal) and b) that
+ * the increment per tick has to fit into 24 bits. As a result we
+ * need to use a shift of 19 so we can fit a value of 16 into the
+ * TIMINCA register.
+ *
*
* SYSTIMH SYSTIML
* +--------------+ +---+---+------+
@@ -95,6 +106,11 @@
struct igb_adapter *igb = container_of(cc, struct igb_adapter, cc);
struct e1000_hw *hw = &igb->hw;
+ /*
+ * The timestamp latches on lowest register read. For the 82580
+ * the lowest register is SYSTIMR instead of SYSTIML. However we only
+ * need to provide nanosecond resolution, so we just ignore it.
+ */
jk = rd32(E1000_SYSTIMR);
lo = rd32(E1000_SYSTIML);
hi = rd32(E1000_SYSTIMH);
@@ -320,3 +336,46 @@
adapter->netdev->name);
}
}
+
+/**
+ * igb_systim_to_hwtstamp - convert system time value to hw timestamp
+ * @adapter: board private structure
+ * @hwtstamps: timestamp structure to update
+ * @systim: unsigned 64bit system time value.
+ *
+ * We need to convert the system time value stored in the RX/TXSTMP registers
+ * into a hwtstamp which can be used by the upper level timestamping functions.
+ *
+ * The 'tmreg_lock' spinlock is used to protect the consistency of the
+ * system time value. This is needed because reading the 64 bit time
+ * value involves reading two (or three) 32 bit registers. The first
+ * read latches the value. Ditto for writing.
+ *
+ * In addition, here have extended the system time with an overflow
+ * counter in software.
+ **/
+void igb_systim_to_hwtstamp(struct igb_adapter *adapter,
+ struct skb_shared_hwtstamps *hwtstamps,
+ u64 systim)
+{
+ u64 ns;
+ unsigned long flags;
+
+ switch (adapter->hw.mac.type) {
+ case e1000_i350:
+ case e1000_82580:
+ case e1000_82576:
+ break;
+ default:
+ return;
+ }
+
+ spin_lock_irqsave(&adapter->tmreg_lock, flags);
+
+ ns = timecounter_cyc2time(&adapter->tc, systim);
+
+ spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
+
+ memset(hwtstamps, 0, sizeof(*hwtstamps));
+ hwtstamps->hwtstamp = ns_to_ktime(ns);
+}