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igb: offer a PTP Hardware Clock instead of the timecompare method
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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>
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Richard Cochran authored and Jeff Kirsher committed Apr 4, 2012
1 parent d339b13 commit 7ebae81
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Showing 5 changed files with 93 additions and 169 deletions.
11 changes: 11 additions & 0 deletions drivers/net/ethernet/intel/Kconfig
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Original file line number Diff line number Diff line change
Expand Up @@ -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
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1 change: 1 addition & 0 deletions drivers/net/ethernet/intel/igb/Makefile
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Original file line number Diff line number Diff line change
Expand Up @@ -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
13 changes: 8 additions & 5 deletions drivers/net/ethernet/intel/igb/igb.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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>
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -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)
Expand Down
178 changes: 14 additions & 164 deletions drivers/net/ethernet/intel/igb/igb_main.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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 *);
Expand Down Expand Up @@ -565,33 +564,6 @@ static void igb_dump(struct igb_adapter *adapter)
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
Expand Down Expand Up @@ -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",
Expand Down Expand Up @@ -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.
Expand Down Expand Up @@ -2303,112 +2280,6 @@ static void __devinit igb_probe_vfs(struct igb_adapter * adapter)
#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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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)
Expand Down Expand Up @@ -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);
Expand Down
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