From 7ebae8177e615d3137d5365757d9d5d7d6ca8a98 Mon Sep 17 00:00:00 2001 From: Richard Cochran Date: Fri, 16 Mar 2012 10:55:37 +0000 Subject: [PATCH] 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 Tested-by: Aaron Brown Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/Kconfig | 11 ++ drivers/net/ethernet/intel/igb/Makefile | 1 + drivers/net/ethernet/intel/igb/igb.h | 13 +- drivers/net/ethernet/intel/igb/igb_main.c | 178 ++-------------------- drivers/net/ethernet/intel/igb/igb_ptp.c | 59 +++++++ 5 files changed, 93 insertions(+), 169 deletions(-) diff --git a/drivers/net/ethernet/intel/Kconfig b/drivers/net/ethernet/intel/Kconfig index 76213162fbe3..90142aa398c6 100644 --- a/drivers/net/ethernet/intel/Kconfig +++ b/drivers/net/ethernet/intel/Kconfig @@ -120,6 +120,17 @@ config IGB_DCA 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 6565c463185c..4bd16e266414 100644 --- a/drivers/net/ethernet/intel/igb/Makefile +++ b/drivers/net/ethernet/intel/igb/Makefile @@ -35,3 +35,4 @@ obj-$(CONFIG_IGB) += igb.o igb-objs := igb_main.o igb_ethtool.o e1000_82575.o \ e1000_mac.o e1000_nvm.o e1000_phy.o e1000_mbx.o +igb-$(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 f0265e851d9f..3758ad246742 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 -#include #include #include #include @@ -329,9 +328,6 @@ struct igb_adapter { /* 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 @@ struct igb_adapter { #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 void igb_update_stats(struct igb_adapter *, struct rtnl_link_stats64 *); 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 5ec31598ee47..f022ff7900f7 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_free_all_rx_resources(struct igb_adapter *); 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 @@ exit: 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 @@ static int __devinit igb_probe(struct pci_dev *pdev, } #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 @@ static void __devexit igb_remove(struct pci_dev *pdev) 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. @@ -2303,112 +2280,6 @@ out: #endif /* CONFIG_PCI_IOV */ } -/** - * 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 @@ static int igb_poll(struct napi_struct *napi, int budget) 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 @@ static void igb_tx_hwtstamp(struct igb_q_vector *q_vector, 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 @@ static bool igb_clean_tx_irq(struct igb_q_vector *q_vector) 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 @@ static inline void igb_rx_hash(struct igb_ring *ring, 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 @@ static void igb_rx_hwtstamp(struct igb_q_vector *q_vector, 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 @@ static bool igb_clean_rx_irq(struct igb_q_vector *q_vector, int budget) 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 c8254cf1456d..c9b71c5bc475 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 @@ static cycle_t igb_82580_systim_read(const struct cyclecounter *cc) 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 @@ void igb_ptp_remove(struct igb_adapter *adapter) 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); +} -- 2.20.1