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Commit a6f73460 authored by Laurence Evans's avatar Laurence Evans Committed by Ben Hutchings
Browse files

sfc: Add support for SFC9100 timestamp format 



The clock minor tick on the SFC9100 family is 2^-27 s, not 1 ns.
There are also various pipeline delays which we need to correct for
when interpreting timestamps.

We query the firmware for the clock format and corrections at run-time.

[bwh: Combined and rebased several changes]
Signed-off-by: default avatarBen Hutchings <bhutchings@solarflare.com>
parent dfd8d581

drivers/net/ethernet/sfc/ptp.c

+231 −25
Original line number Diff line number Diff line
@@ -62,7 +62,7 @@ 
#define	SYNCHRONISATION_GRANULARITY_NS	200



/* Minimum permitted length of a (corrected) synchronisation time */

#define	MIN_SYNCHRONISATION_NS		120

#define	DEFAULT_MIN_SYNCHRONISATION_NS	120



/* Maximum permitted length of a (corrected) synchronisation time */

#define	MAX_SYNCHRONISATION_NS		1000
@@ -195,20 +195,20 @@ struct efx_ptp_event_rx { 
/**

 * struct efx_ptp_timeset - Synchronisation between host and MC

 * @host_start: Host time immediately before hardware timestamp taken

 * @seconds: Hardware timestamp, seconds

 * @nanoseconds: Hardware timestamp, nanoseconds

 * @major: Hardware timestamp, major

 * @minor: Hardware timestamp, minor

 * @host_end: Host time immediately after hardware timestamp taken

 * @waitns: Number of nanoseconds between hardware timestamp being read and

 * @wait: Number of NIC clock ticks between hardware timestamp being read and

 *          host end time being seen

 * @window: Difference of host_end and host_start

 * @valid: Whether this timeset is valid

 */

struct efx_ptp_timeset {

	u32 host_start;

	u32 seconds;

	u32 nanoseconds;

	u32 major;

	u32 minor;

	u32 host_end;

	u32 waitns;

	u32 wait;

	u32 window;	/* Derived: end - start, allowing for wrap */

};
@@ -232,6 +232,14 @@ struct efx_ptp_timeset { 
 * @config: Current timestamp configuration

 * @enabled: PTP operation enabled

 * @mode: Mode in which PTP operating (PTP version)

 * @time_format: Time format supported by this NIC

 * @ns_to_nic_time: Function to convert from scalar nanoseconds to NIC time

 * @nic_to_kernel_time: Function to convert from NIC to kernel time

 * @min_synchronisation_ns: Minimum acceptable corrected sync window

 * @ts_corrections.tx: Required driver correction of transmit timestamps

 * @ts_corrections.rx: Required driver correction of receive timestamps

 * @ts_corrections.pps_out: PPS output error (information only)

 * @ts_corrections.pps_in: Required driver correction of PPS input timestamps

 * @evt_frags: Partly assembled PTP events

 * @evt_frag_idx: Current fragment number

 * @evt_code: Last event code
@@ -266,6 +274,17 @@ struct efx_ptp_data { 
	struct hwtstamp_config config;

	bool enabled;

	unsigned int mode;

	unsigned int time_format;

	void (*ns_to_nic_time)(s64 ns, u32 *nic_major, u32 *nic_minor);

	ktime_t (*nic_to_kernel_time)(u32 nic_major, u32 nic_minor,

				      s32 correction);

	unsigned int min_synchronisation_ns;

	struct {

		s32 tx;

		s32 rx;

		s32 pps_out;

		s32 pps_in;

	} ts_corrections;

	efx_qword_t evt_frags[MAX_EVENT_FRAGS];

	int evt_frag_idx;

	int evt_code;
@@ -290,6 +309,167 @@ static int efx_phc_settime(struct ptp_clock_info *ptp, 
static int efx_phc_enable(struct ptp_clock_info *ptp,

			  struct ptp_clock_request *request, int on);



/* For Siena platforms NIC time is s and ns */

static void efx_ptp_ns_to_s_ns(s64 ns, u32 *nic_major, u32 *nic_minor)

{

	struct timespec ts = ns_to_timespec(ns);

	*nic_major = ts.tv_sec;

	*nic_minor = ts.tv_nsec;

}



static ktime_t efx_ptp_s_ns_to_ktime(u32 nic_major, u32 nic_minor,

				     s32 correction)

{

	ktime_t kt = ktime_set(nic_major, nic_minor);

	if (correction >= 0)

		kt = ktime_add_ns(kt, (u64)correction);

	else

		kt = ktime_sub_ns(kt, (u64)-correction);

	return kt;

}



/* To convert from s27 format to ns we multiply then divide by a power of 2.

 * For the conversion from ns to s27, the operation is also converted to a

 * multiply and shift.

 */

#define S27_TO_NS_SHIFT	(27)

#define NS_TO_S27_MULT	(((1ULL << 63) + NSEC_PER_SEC / 2) / NSEC_PER_SEC)

#define NS_TO_S27_SHIFT	(63 - S27_TO_NS_SHIFT)

#define S27_MINOR_MAX	(1 << S27_TO_NS_SHIFT)



/* For Huntington platforms NIC time is in seconds and fractions of a second

 * where the minor register only uses 27 bits in units of 2^-27s.

 */

static void efx_ptp_ns_to_s27(s64 ns, u32 *nic_major, u32 *nic_minor)

{

	struct timespec ts = ns_to_timespec(ns);

	u32 maj = ts.tv_sec;

	u32 min = (u32)(((u64)ts.tv_nsec * NS_TO_S27_MULT +

			 (1ULL << (NS_TO_S27_SHIFT - 1))) >> NS_TO_S27_SHIFT);



	/* The conversion can result in the minor value exceeding the maximum.

	 * In this case, round up to the next second.

	 */

	if (min >= S27_MINOR_MAX) {

		min -= S27_MINOR_MAX;

		maj++;

	}



	*nic_major = maj;

	*nic_minor = min;

}



static ktime_t efx_ptp_s27_to_ktime(u32 nic_major, u32 nic_minor,

				    s32 correction)

{

	u32 ns;



	/* Apply the correction and deal with carry */

	nic_minor += correction;

	if ((s32)nic_minor < 0) {

		nic_minor += S27_MINOR_MAX;

		nic_major--;

	} else if (nic_minor >= S27_MINOR_MAX) {

		nic_minor -= S27_MINOR_MAX;

		nic_major++;

	}



	ns = (u32)(((u64)nic_minor * NSEC_PER_SEC +

		    (1ULL << (S27_TO_NS_SHIFT - 1))) >> S27_TO_NS_SHIFT);



	return ktime_set(nic_major, ns);

}



/* Get PTP attributes and set up time conversions */

static int efx_ptp_get_attributes(struct efx_nic *efx)

{

	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_GET_ATTRIBUTES_LEN);

	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_GET_ATTRIBUTES_LEN);

	struct efx_ptp_data *ptp = efx->ptp_data;

	int rc;

	u32 fmt;

	size_t out_len;



	/* Get the PTP attributes. If the NIC doesn't support the operation we

	 * use the default format for compatibility with older NICs i.e.

	 * seconds and nanoseconds.

	 */

	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_GET_ATTRIBUTES);

	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);

	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),

			  outbuf, sizeof(outbuf), &out_len);

	if (rc == 0)

		fmt = MCDI_DWORD(outbuf, PTP_OUT_GET_ATTRIBUTES_TIME_FORMAT);

	else if (rc == -EINVAL)

		fmt = MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_NANOSECONDS;

	else

		return rc;



	if (fmt == MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_27FRACTION) {

		ptp->ns_to_nic_time = efx_ptp_ns_to_s27;

		ptp->nic_to_kernel_time = efx_ptp_s27_to_ktime;

	} else if (fmt == MC_CMD_PTP_OUT_GET_ATTRIBUTES_SECONDS_NANOSECONDS) {

		ptp->ns_to_nic_time = efx_ptp_ns_to_s_ns;

		ptp->nic_to_kernel_time = efx_ptp_s_ns_to_ktime;

	} else {

		return -ERANGE;

	}



	ptp->time_format = fmt;



	/* MC_CMD_PTP_OP_GET_ATTRIBUTES is an extended version of an older

	 * operation MC_CMD_PTP_OP_GET_TIME_FORMAT that also returns a value

	 * to use for the minimum acceptable corrected synchronization window.

	 * If we have the extra information store it. For older firmware that

	 * does not implement the extended command use the default value.

	 */

	if (rc == 0 && out_len >= MC_CMD_PTP_OUT_GET_ATTRIBUTES_LEN)

		ptp->min_synchronisation_ns =

			MCDI_DWORD(outbuf,

				   PTP_OUT_GET_ATTRIBUTES_SYNC_WINDOW_MIN);

	else

		ptp->min_synchronisation_ns = DEFAULT_MIN_SYNCHRONISATION_NS;



	return 0;

}



/* Get PTP timestamp corrections */

static int efx_ptp_get_timestamp_corrections(struct efx_nic *efx)

{

	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_GET_TIMESTAMP_CORRECTIONS_LEN);

	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_GET_TIMESTAMP_CORRECTIONS_LEN);

	int rc;



	/* Get the timestamp corrections from the NIC. If this operation is

	 * not supported (older NICs) then no correction is required.

	 */

	MCDI_SET_DWORD(inbuf, PTP_IN_OP,

		       MC_CMD_PTP_OP_GET_TIMESTAMP_CORRECTIONS);

	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);



	rc = efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),

			  outbuf, sizeof(outbuf), NULL);

	if (rc == 0) {

		efx->ptp_data->ts_corrections.tx = MCDI_DWORD(outbuf,

			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_TRANSMIT);

		efx->ptp_data->ts_corrections.rx = MCDI_DWORD(outbuf,

			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_RECEIVE);

		efx->ptp_data->ts_corrections.pps_out = MCDI_DWORD(outbuf,

			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_PPS_OUT);

		efx->ptp_data->ts_corrections.pps_in = MCDI_DWORD(outbuf,

			PTP_OUT_GET_TIMESTAMP_CORRECTIONS_PPS_IN);

	} else if (rc == -EINVAL) {

		efx->ptp_data->ts_corrections.tx = 0;

		efx->ptp_data->ts_corrections.rx = 0;

		efx->ptp_data->ts_corrections.pps_out = 0;

		efx->ptp_data->ts_corrections.pps_in = 0;

	} else {

		return rc;

	}



	return 0;

}



/* Enable MCDI PTP support. */

static int efx_ptp_enable(struct efx_nic *efx)

{
@@ -402,11 +582,10 @@ static void efx_ptp_read_timeset(MCDI_DECLARE_STRUCT_PTR(data), 
	unsigned start_ns, end_ns;



	timeset->host_start = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_HOSTSTART);

	timeset->seconds = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_SECONDS);

	timeset->nanoseconds = MCDI_DWORD(data,

					 PTP_OUT_SYNCHRONIZE_NANOSECONDS);

	timeset->major = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_MAJOR);

	timeset->minor = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_MINOR);

	timeset->host_end = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_HOSTEND),

	timeset->waitns = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_WAITNS);

	timeset->wait = MCDI_DWORD(data, PTP_OUT_SYNCHRONIZE_WAITNS);



	/* Ignore seconds */

	start_ns = timeset->host_start & MC_NANOSECOND_MASK;
@@ -441,6 +620,7 @@ efx_ptp_process_times(struct efx_nic *efx, MCDI_DECLARE_STRUCT_PTR(synch_buf), 
	u32 last_sec;

	u32 start_sec;

	struct timespec delta;

	ktime_t mc_time;



	if (number_readings == 0)

		return -EAGAIN;
@@ -452,14 +632,17 @@ efx_ptp_process_times(struct efx_nic *efx, MCDI_DECLARE_STRUCT_PTR(synch_buf), 
	 */

	for (i = 0; i < number_readings; i++) {

		s32 window, corrected;

		struct timespec wait;



		efx_ptp_read_timeset(

			MCDI_ARRAY_STRUCT_PTR(synch_buf,

					      PTP_OUT_SYNCHRONIZE_TIMESET, i),

			&ptp->timeset[i]);



		wait = ktime_to_timespec(

			ptp->nic_to_kernel_time(0, ptp->timeset[i].wait, 0));

		window = ptp->timeset[i].window;

		corrected = window - ptp->timeset[i].waitns;

		corrected = window - wait.tv_nsec;



		/* We expect the uncorrected synchronization window to be at

		 * least as large as the interval between host start and end
@@ -472,7 +655,7 @@ efx_ptp_process_times(struct efx_nic *efx, MCDI_DECLARE_STRUCT_PTR(synch_buf), 
		 */

		if (window >= SYNCHRONISATION_GRANULARITY_NS &&

		    corrected < MAX_SYNCHRONISATION_NS &&

		    corrected >= MIN_SYNCHRONISATION_NS) {

		    corrected >= ptp->min_synchronisation_ns) {

			ngood++;

			last_good = i;

		}
@@ -484,9 +667,15 @@ efx_ptp_process_times(struct efx_nic *efx, MCDI_DECLARE_STRUCT_PTR(synch_buf), 
		return -EAGAIN;

	}



	/* Convert the NIC time into kernel time. No correction is required-

	 * this time is the output of a firmware process.

	 */

	mc_time = ptp->nic_to_kernel_time(ptp->timeset[last_good].major,

					  ptp->timeset[last_good].minor, 0);



	/* Calculate delay from actual PPS to last_time */

	delta.tv_nsec =

		ptp->timeset[last_good].nanoseconds +

	delta = ktime_to_timespec(mc_time);

	delta.tv_nsec +=

		last_time->ts_real.tv_nsec -

		(ptp->timeset[last_good].host_start & MC_NANOSECOND_MASK);
@@ -596,9 +785,10 @@ static int efx_ptp_xmit_skb(struct efx_nic *efx, struct sk_buff *skb) 
		goto fail;



	memset(&timestamps, 0, sizeof(timestamps));

	timestamps.hwtstamp = ktime_set(

		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_SECONDS),

		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_NANOSECONDS));

	timestamps.hwtstamp = ptp_data->nic_to_kernel_time(

		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_MAJOR),

		MCDI_DWORD(txtime, PTP_OUT_TRANSMIT_MINOR),

		ptp_data->ts_corrections.tx);



	skb_tstamp_tx(skb, &timestamps);
@@ -954,6 +1144,16 @@ int efx_ptp_probe(struct efx_nic *efx, struct efx_channel *channel) 
		list_add(&ptp->rx_evts[pos].link, &ptp->evt_free_list);

	ptp->evt_overflow = false;



	/* Get the NIC PTP attributes and set up time conversions */

	rc = efx_ptp_get_attributes(efx);

	if (rc < 0)

		goto fail3;



	/* Get the timestamp corrections */

	rc = efx_ptp_get_timestamp_corrections(efx);

	if (rc < 0)

		goto fail3;



	ptp->phc_clock_info = efx_phc_clock_info;

	ptp->phc_clock = ptp_clock_register(&ptp->phc_clock_info,

					    &efx->pci_dev->dev);
@@ -1358,9 +1558,10 @@ static void ptp_event_rx(struct efx_nic *efx, struct efx_ptp_data *ptp) 
					      MCDI_EVENT_SRC) << 8) |

			     (EFX_QWORD_FIELD(ptp->evt_frags[0],

					      MCDI_EVENT_SRC) << 16));

		evt->hwtimestamp = ktime_set(

		evt->hwtimestamp = efx->ptp_data->nic_to_kernel_time(

			EFX_QWORD_FIELD(ptp->evt_frags[0], MCDI_EVENT_DATA),

			EFX_QWORD_FIELD(ptp->evt_frags[1], MCDI_EVENT_DATA));

			EFX_QWORD_FIELD(ptp->evt_frags[1], MCDI_EVENT_DATA),

			ptp->ts_corrections.rx);

		evt->expiry = jiffies + msecs_to_jiffies(PKT_EVENT_LIFETIME_MS);

		list_add_tail(&evt->link, &ptp->evt_list);
@@ -1470,18 +1671,20 @@ static int efx_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta) 


static int efx_phc_adjtime(struct ptp_clock_info *ptp, s64 delta)

{

	u32 nic_major, nic_minor;

	struct efx_ptp_data *ptp_data = container_of(ptp,

						     struct efx_ptp_data,

						     phc_clock_info);

	struct efx_nic *efx = ptp_data->efx;

	struct timespec delta_ts = ns_to_timespec(delta);

	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_ADJUST_LEN);



	efx->ptp_data->ns_to_nic_time(delta, &nic_major, &nic_minor);



	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_ADJUST);

	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);

	MCDI_SET_QWORD(inbuf, PTP_IN_ADJUST_FREQ, ptp_data->current_adjfreq);

	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_SECONDS, (u32)delta_ts.tv_sec);

	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_NANOSECONDS, (u32)delta_ts.tv_nsec);

	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_MAJOR, nic_major);

	MCDI_SET_DWORD(inbuf, PTP_IN_ADJUST_MINOR, nic_minor);

	return efx_mcdi_rpc(efx, MC_CMD_PTP, inbuf, sizeof(inbuf),

			    NULL, 0, NULL);

}
@@ -1495,6 +1698,7 @@ static int efx_phc_gettime(struct ptp_clock_info *ptp, struct timespec *ts) 
	MCDI_DECLARE_BUF(inbuf, MC_CMD_PTP_IN_READ_NIC_TIME_LEN);

	MCDI_DECLARE_BUF(outbuf, MC_CMD_PTP_OUT_READ_NIC_TIME_LEN);

	int rc;

	ktime_t kt;



	MCDI_SET_DWORD(inbuf, PTP_IN_OP, MC_CMD_PTP_OP_READ_NIC_TIME);

	MCDI_SET_DWORD(inbuf, PTP_IN_PERIPH_ID, 0);
@@ -1504,8 +1708,10 @@ static int efx_phc_gettime(struct ptp_clock_info *ptp, struct timespec *ts) 
	if (rc != 0)

		return rc;



	ts->tv_sec = MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_SECONDS);

	ts->tv_nsec = MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_NANOSECONDS);

	kt = ptp_data->nic_to_kernel_time(

		MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_MAJOR),

		MCDI_DWORD(outbuf, PTP_OUT_READ_NIC_TIME_MINOR), 0);

	*ts = ktime_to_timespec(kt);

	return 0;

}