diff mbox series

[05/15] pciutils-pcilmr: Add margining process functions

Message ID 20231208091734.12225-6-n.proshkin@yadro.com (mailing list archive)
State Superseded
Headers show
Series pciutils: Add utility for Lane Margining | expand

Commit Message

Nikita Proshkin Dec. 8, 2023, 9:17 a.m. UTC
* Implement the margining flow as described in the section "Example
  Software Flow for Lane Margining at Receiver" of the 5.0 spec;
* Implement margining commands formation and response parsing according
  to the table 4-26;
* Use Receiver margining parameters as described in the table 8-11;
* Support lane reversal and simultaneous margining of several link lanes.

Reviewed-by: Sergei Miroshnichenko <s.miroshnichenko@yadro.com>
Signed-off-by: Nikita Proshkin <n.proshkin@yadro.com>
---
 lmr_lib/Makefile |   2 +-
 lmr_lib/margin.c | 404 +++++++++++++++++++++++++++++++++++++++++++++++
 lmr_lib/margin.h | 197 +++++++++++++++++++++++
 3 files changed, 602 insertions(+), 1 deletion(-)
 create mode 100644 lmr_lib/margin.c
 create mode 100644 lmr_lib/margin.h

Comments

Martin Mareš Dec. 8, 2023, 5:35 p.m. UTC | #1
> +  if (msec < 0)
> +  {
> +    errno = EINVAL;
> +    return -1;
> +  }
[...]

Please follow the indentation style of the rest of pciutils.

> +union margin_payload {
> +  unsigned int payload : 8;
> +
> +  struct caps {
> +    bool volt_support : 1;
> +    bool ind_up_down_volt : 1;
> +    bool ind_left_right_tim : 1;
> +    bool sample_report_method : 1;
> +    bool ind_error_sampler : 1;
> +  } caps;
> +
> +  unsigned int timing_steps : 6;
> +  unsigned int voltage_steps : 7;
> +  unsigned int offset : 7;
> +  unsigned int max_lanes : 5;
> +  unsigned int sample_rate : 6;
> +
> +  struct step_resp {
> +    unsigned int err_count : 6;
> +    unsigned int status : 2;
> +  } step_resp;
> +
> +  struct step_tim {
> +    unsigned int steps : 6;
> +    bool go_left : 1;
> +  } step_tim;
> +
> +  struct step_volt {
> +    unsigned int steps : 7;
> +    bool go_down : 1;
> +  } step_volt;
> +
> +} __attribute__((packed));

Please do not assume that every compiler used to compile the pciutils supports
GCC extensions. See lib/sysdep.h for how we handle such things.

Also, I am not sure that bit fields are good idea: they save a little data
space, but they expand code.

				Have a nice fortnight
Nikita Proshkin Dec. 13, 2023, 10:35 a.m. UTC | #2
On Fri, 8 Dec 2023 18:35:58 +0100
Martin Mareš <mj@ucw.cz> wrote:

> > +union margin_payload {
> > +  unsigned int payload : 8;
> > +
> > +  struct caps {
> > +    bool volt_support : 1;
> > +    bool ind_up_down_volt : 1;
> > +    bool ind_left_right_tim : 1;
> > +    bool sample_report_method : 1;
> > +    bool ind_error_sampler : 1;
> > +  } caps;
> > +
> > +  unsigned int timing_steps : 6;
> > +  unsigned int voltage_steps : 7;
> > +  unsigned int offset : 7;
> > +  unsigned int max_lanes : 5;
> > +  unsigned int sample_rate : 6;
> > +
> > +  struct step_resp {
> > +    unsigned int err_count : 6;
> > +    unsigned int status : 2;
> > +  } step_resp;
> > +
> > +  struct step_tim {
> > +    unsigned int steps : 6;
> > +    bool go_left : 1;
> > +  } step_tim;
> > +
> > +  struct step_volt {
> > +    unsigned int steps : 7;
> > +    bool go_down : 1;
> > +  } step_volt;
> > +
> > +} __attribute__((packed));
> 
> Please do not assume that every compiler used to compile the pciutils supports
> GCC extensions. See lib/sysdep.h for how we handle such things.
> 
> Also, I am not sure that bit fields are good idea: they save a little data
> space, but they expand code.

I had an idea to use anonymous structures here, which would make field
accesses shorter. And actually I would prefer to use bit fields instead of
manipulating bits. But looks like it will be hard to implement this
approach without using GCC packed feature and make it portable.
It seems that I will have to implement the option with a pack of macro 
wrappers around bit masks.

Best regards,
Nikita Proshkin
diff mbox series

Patch

diff --git a/lmr_lib/Makefile b/lmr_lib/Makefile
index 4f85a17..2003a67 100644
--- a/lmr_lib/Makefile
+++ b/lmr_lib/Makefile
@@ -1,4 +1,4 @@ 
-OBJS=margin_hw
+OBJS=margin_hw margin
 INCL=$(addsuffix .h,$(OBJS)) $(addprefix ../,$(PCIINC))
 
 $(addsuffix .o, $(OBJS)): %.o: %.c $(INCL)
diff --git a/lmr_lib/margin.c b/lmr_lib/margin.c
new file mode 100644
index 0000000..9d25973
--- /dev/null
+++ b/lmr_lib/margin.c
@@ -0,0 +1,404 @@ 
+#include <errno.h>
+#include <time.h>
+#include <stdio.h>
+#include <malloc.h>
+
+#include "margin.h"
+
+#define MARG_LANE_CTRL(lmr_cap_addr, lane) ((lmr_cap_addr) + 8 + 4 * (lane))
+#define MARG_LANE_STATUS(lmr_cap_addr, lane) ((lmr_cap_addr) + 10 + 4 * (lane))
+
+#define MARG_TIM(go_left, step, recvn) margin_make_cmd(((go_left) << 6) | (step), 3, recvn)
+#define MARG_VOLT(go_down, step, recvn) margin_make_cmd(((go_down) << 7) | (step), 4, recvn)
+
+// report commands
+#define REPORT_CAPS(recvn) margin_make_cmd(0x88, 1, recvn)
+#define REPORT_VOL_STEPS(recvn) margin_make_cmd(0x89, 1, recvn)
+#define REPORT_TIM_STEPS(recvn) margin_make_cmd(0x8A, 1, recvn)
+#define REPORT_TIM_OFFSET(recvn) margin_make_cmd(0x8B, 1, recvn)
+#define REPORT_VOL_OFFSET(recvn) margin_make_cmd(0x8C, 1, recvn)
+#define REPORT_SAMPL_RATE_V(recvn) margin_make_cmd(0x8D, 1, recvn)
+#define REPORT_SAMPL_RATE_T(recvn) margin_make_cmd(0x8E, 1, recvn)
+#define REPORT_SAMPLE_CNT(recvn) margin_make_cmd(0x8F, 1, recvn)
+#define REPORT_MAX_LANES(recvn) margin_make_cmd(0x90, 1, recvn)
+
+// set commands
+#define NO_COMMAND margin_make_cmd(0x9C, 7, 0)
+#define CLEAR_ERROR_LOG(recvn) margin_make_cmd(0x55, 2, recvn)
+#define GO_TO_NORMAL_SETTINGS(recvn) margin_make_cmd(0xF, 2, recvn)
+#define SET_ERROR_LIMIT(error_limit, recvn) margin_make_cmd(0xC0 | (error_limit), 2, recvn)
+
+static int msleep(long msec)
+{
+  struct timespec ts;
+  int res;
+
+  if (msec < 0)
+  {
+    errno = EINVAL;
+    return -1;
+  }
+
+  ts.tv_sec = msec / 1000;
+  ts.tv_nsec = (msec % 1000) * 1000000;
+
+  do
+  {
+    res = nanosleep(&ts, &ts);
+  } while (res && errno == EINTR);
+
+  return res;
+}
+
+union margin_cmd margin_make_cmd(uint8_t payload, uint8_t type, uint8_t recvn)
+{
+  return (union margin_cmd){.fields = {.payload.payload = payload, .recvn = recvn, 
+                                      .type = type, .reserved = 0}};
+}
+
+bool margin_read_params(struct margin_recv *recv)
+{
+  union margin_payload resp;
+  uint8_t lane = recv->lane_reversal ? recv->dev->width - 1 : 0;
+  margin_set_cmd(recv->dev, lane, NO_COMMAND);
+  bool status = margin_report_cmd(recv->dev, lane, REPORT_CAPS(recv->recvn), &resp);
+  if (status)
+  {
+    recv->volt_support = resp.caps.volt_support;
+    recv->ind_up_down_volt = resp.caps.ind_up_down_volt;
+    recv->ind_left_right_tim = resp.caps.ind_left_right_tim;
+    recv->sample_report_method = resp.caps.sample_report_method;
+    recv->ind_error_sampler = resp.caps.ind_error_sampler;
+    status = margin_report_cmd(recv->dev, lane, REPORT_VOL_STEPS(recv->recvn), &resp);
+  }
+  if (status)
+  {
+    recv->volt_steps = resp.voltage_steps;
+    status = margin_report_cmd(recv->dev, lane, REPORT_TIM_STEPS(recv->recvn), &resp);
+  }
+  if (status)
+  {
+    recv->timing_steps = resp.timing_steps;
+    status = margin_report_cmd(recv->dev, lane, REPORT_TIM_OFFSET(recv->recvn), &resp);
+  }
+  if (status)
+  {
+    recv->timing_offset = resp.offset;
+    status = margin_report_cmd(recv->dev, lane, REPORT_VOL_OFFSET(recv->recvn), &resp);
+  }
+  if (status)
+  {
+    recv->volt_offset = resp.offset;
+    status = margin_report_cmd(recv->dev, lane, REPORT_SAMPL_RATE_V(recv->recvn), &resp);
+  }
+  if (status)
+  {
+    recv->sample_rate_v = resp.sample_rate;
+    status = margin_report_cmd(recv->dev, lane, REPORT_SAMPL_RATE_T(recv->recvn), &resp);
+  }
+  if (status)
+  {
+    recv->sample_rate_t = resp.sample_rate;
+    status = margin_report_cmd(recv->dev, lane, REPORT_MAX_LANES(recv->recvn), &resp);
+  }
+  if (status)
+    recv->max_lanes = resp.max_lanes;
+  return status;
+}
+
+bool margin_report_cmd(struct margin_dev *dev, uint8_t lane, 
+                       union margin_cmd cmd, union margin_payload *result)
+{
+  pci_write_word(dev->dev, MARG_LANE_CTRL(dev->lmr_cap_addr, lane), cmd.cmd);
+  msleep(10);
+  union margin_cmd resp;
+  resp.cmd = pci_read_word(dev->dev, MARG_LANE_STATUS(dev->lmr_cap_addr, lane));
+  *result = resp.fields.payload;
+  return resp.fields.type == cmd.fields.type && resp.fields.recvn == cmd.fields.recvn 
+          && margin_set_cmd(dev, lane, NO_COMMAND);
+}
+
+bool margin_set_cmd(struct margin_dev *dev, uint8_t lane, union margin_cmd cmd)
+{
+  pci_write_word(dev->dev, MARG_LANE_CTRL(dev->lmr_cap_addr, lane), cmd.cmd);
+  msleep(10);
+  return pci_read_word(dev->dev, MARG_LANE_STATUS(dev->lmr_cap_addr, lane)) == cmd.cmd;
+}
+
+void margin_lanes(struct margin_lanes_data arg)
+{
+  uint8_t steps_done = 0;
+  union margin_cmd lane_status;
+  uint8_t marg_type;
+  union margin_cmd step_cmd;
+  bool timing = (arg.dir == TIM_LEFT || arg.dir == TIM_RIGHT);
+
+  if (timing)
+  {
+    marg_type = 3;
+    step_cmd = MARG_TIM(arg.dir == TIM_LEFT, steps_done, arg.recv->recvn);
+  }
+  else
+  {
+    marg_type = 4;
+    step_cmd = MARG_VOLT(arg.dir == VOLT_DOWN, steps_done, arg.recv->recvn);
+  }
+
+  bool failed_lanes[32] = {0};
+  uint8_t alive_lanes = arg.lanes_n;
+
+  for (uint8_t i = 0; i < arg.lanes_n; i++)
+  {
+    margin_set_cmd(arg.recv->dev, arg.results[i].lane, NO_COMMAND);
+    margin_set_cmd(arg.recv->dev, arg.results[i].lane, SET_ERROR_LIMIT(arg.recv->error_limit, arg.recv->recvn));
+    margin_set_cmd(arg.recv->dev, arg.results[i].lane, NO_COMMAND);
+    arg.results[i].steps[arg.dir] = arg.steps_lane_total;
+    arg.results[i].statuses[arg.dir] = MARGIN_THR;
+  }
+
+  while (alive_lanes > 0 && steps_done < arg.steps_lane_total)
+  {
+    alive_lanes = 0;
+    steps_done++;
+    if (timing)
+      step_cmd.fields.payload.step_tim.steps = steps_done;
+    else
+      step_cmd.fields.payload.step_volt.steps = steps_done;
+
+    for (uint8_t i = 0; i < arg.lanes_n; i++)
+    {
+      if (!failed_lanes[i])
+      {
+        alive_lanes++;
+        int ctrl_addr = MARG_LANE_CTRL(arg.recv->dev->lmr_cap_addr, arg.results[i].lane);
+        pci_write_word(arg.recv->dev->dev, ctrl_addr, step_cmd.cmd);
+      }
+    }
+    msleep(MARGIN_STEP_MS);
+
+    for (uint8_t i = 0; i < arg.lanes_n; i++)
+    {
+      if (!failed_lanes[i])
+      {
+        int status_addr = MARG_LANE_STATUS(arg.recv->dev->lmr_cap_addr, arg.results[i].lane);
+        lane_status.cmd = pci_read_word(arg.recv->dev->dev, status_addr);
+        uint8_t step_status = lane_status.fields.payload.step_resp.status;
+        if (!(lane_status.fields.type == marg_type && lane_status.fields.recvn == arg.recv->recvn 
+            && step_status == 2 && lane_status.fields.payload.step_resp.err_count <= arg.recv->error_limit
+            && margin_set_cmd(arg.recv->dev, arg.results[i].lane, NO_COMMAND))) 
+        {
+          alive_lanes--;
+          failed_lanes[i] = true;
+          arg.results[i].steps[arg.dir] = steps_done - 1;
+          arg.results[i].statuses[arg.dir] = (step_status == 3 || step_status == 1 ? MARGIN_NAK : MARGIN_LIM);
+        }
+      }
+    }
+
+    arg.steps_lane_done = steps_done;
+  }
+
+  for (uint8_t i = 0; i < arg.lanes_n; i++)
+  {
+    margin_set_cmd(arg.recv->dev, arg.results[i].lane, NO_COMMAND);
+    margin_set_cmd(arg.recv->dev, arg.results[i].lane, CLEAR_ERROR_LOG(arg.recv->recvn));
+    margin_set_cmd(arg.recv->dev, arg.results[i].lane, NO_COMMAND);
+    margin_set_cmd(arg.recv->dev, arg.results[i].lane, GO_TO_NORMAL_SETTINGS(arg.recv->recvn));
+    margin_set_cmd(arg.recv->dev, arg.results[i].lane, NO_COMMAND);
+  }
+}
+
+bool margin_receiver(struct margin_recv *recv, struct margin_args *args, struct margin_results *results)
+{
+  bool status = true;
+
+  uint8_t *lanes_to_margin = args->lanes;
+  uint8_t lanes_n = args->lanes_n;
+
+  results->recvn = recv->recvn;
+  recv->error_limit = args->error_limit;
+  recv->parallel_lanes = (args->parallel_lanes < 0 ? 1 : args->parallel_lanes);
+  results->lanes_n = lanes_n;
+
+  if (!margin_check_ready_bit(recv->dev->dev))
+  {
+    results->test_status = MARGIN_TEST_READY_BIT;
+    status = false;
+  }
+
+  if (status)
+  {
+    recv->lane_reversal = false;
+    if (!margin_read_params(recv))
+    {
+      recv->lane_reversal = true;
+      if (!margin_read_params(recv))
+      {
+        results->test_status = MARGIN_TEST_CAPS;
+        status = false;
+      }
+    }
+  }
+
+  if (status)
+  {
+    if (recv->parallel_lanes > recv->max_lanes + 1)
+      recv->parallel_lanes = recv->max_lanes + 1;
+
+    results->tim_coef = (double)recv->timing_offset / (double)recv->timing_steps;
+    results->volt_coef = (double)recv->volt_offset / (double)recv->volt_steps * 10.0;
+
+    results->ind_left_right_tim = recv->ind_left_right_tim;
+    results->volt_support = recv->volt_support;
+    results->ind_up_down_volt = recv->ind_up_down_volt;
+    results->lane_reversal = recv->lane_reversal;
+    results->link_speed = recv->dev->link_speed;
+    results->test_status = MARGIN_TEST_OK;
+
+    results->lanes = malloc(sizeof(struct margin_res_lane) * lanes_n);
+    for (uint8_t i = 0; i < lanes_n; i++)
+    {
+      results->lanes[i].lane = recv->lane_reversal ? recv->dev->width - lanes_to_margin[i] - 1 : lanes_to_margin[i];
+    }
+
+    if (args->run_margin)
+    {
+      struct margin_lanes_data margin_lanes_data = {.recv = recv,
+                                                    .verbosity = args->verbosity,
+                                                    .steps_margin_remaining = args->steps_margin_remaining};
+      enum margin_dir dir[] = {TIM_LEFT, TIM_RIGHT, VOLT_UP, VOLT_DOWN};
+
+      uint8_t lanes_done = 0;
+      uint8_t use_lanes = 0;
+      uint8_t steps_t = (args->steps_t < 0 ? recv->timing_steps : args->steps_t);
+      uint8_t steps_v = (args->steps_v < 0 ? recv->volt_steps : args->steps_v);
+      while (lanes_done != lanes_n)
+      {
+        use_lanes = (lanes_done + recv->parallel_lanes > lanes_n) ? lanes_n - lanes_done : recv->parallel_lanes;
+        margin_lanes_data.lanes_numbers = lanes_to_margin + lanes_done;
+        margin_lanes_data.lanes_n = use_lanes;
+        margin_lanes_data.results = results->lanes + lanes_done;
+
+        for (uint8_t i = 0; i < 4; i++)
+        {
+          bool timing = dir[i] == TIM_LEFT || dir[i] == TIM_RIGHT;
+          if (!timing && !recv->volt_support)
+            continue;
+          if (dir[i] == TIM_RIGHT && !recv->ind_left_right_tim)
+            continue;
+          if (dir[i] == VOLT_DOWN && !recv->ind_up_down_volt)
+            continue;
+
+          margin_lanes_data.ind = timing ? recv->ind_left_right_tim : recv->ind_up_down_volt;
+          margin_lanes_data.dir = dir[i];
+          margin_lanes_data.steps_lane_total = timing ? steps_t : steps_v;
+          if (*args->steps_margin_remaining >= margin_lanes_data.steps_lane_total)
+          {
+            *args->steps_margin_remaining -= margin_lanes_data.steps_lane_total;
+          }
+          else
+            *args->steps_margin_remaining = 0;
+          margin_lanes(margin_lanes_data);
+        }
+        lanes_done += use_lanes;
+      }
+      if (recv->lane_reversal)
+      {
+        for (uint8_t i = 0; i < lanes_n; i++)
+          results->lanes[i].lane = lanes_to_margin[i];
+      }
+    }
+  }
+
+  return status;
+}
+
+enum margin_test_status margin_process_args(struct margin_dev *dev, struct margin_args *args)
+{
+  uint8_t receivers_n = 2 + 2 * dev->retimers_n;
+
+  if (args->recvs_n <= 0)
+  {
+    for (uint8_t i = 1; i < receivers_n; i++)
+      args->recvs[i - 1] = i;
+    args->recvs[receivers_n - 1] = 6;
+    args->recvs_n = receivers_n;
+  }
+  else
+  {
+    for (uint8_t i = 0; i < args->recvs_n; i++)
+    {
+      uint8_t recvn = args->recvs[i];
+      if (recvn < 1 || recvn > 6 || (recvn != 6 && recvn > receivers_n - 1))
+      {
+        return MARGIN_TEST_ARGS_RECVS;
+      }
+    }
+  }
+
+  if (args->lanes_n <= 0)
+  {
+    args->lanes_n = dev->width;
+    for (uint8_t i = 0; i < args->lanes_n; i++)
+      args->lanes[i] = i;
+  }
+  else
+  {
+    for (uint8_t i = 0; i < args->lanes_n; i++)
+    {
+      if (args->lanes[i] >= dev->width)
+      {
+        return MARGIN_TEST_ARGS_LANES;
+      }
+    }
+  }
+
+  return MARGIN_TEST_OK;
+}
+
+struct margin_results *margin_link(struct margin_dev *down_port, struct margin_dev *up_port, 
+                                   struct margin_args *args, uint8_t *recvs_n)
+{
+  bool status = true;
+
+  status = margin_prep_dev(down_port);
+  if (status)
+    status = margin_prep_dev(up_port);
+
+  uint8_t receivers_n = status ? args->recvs_n : 1;
+  uint8_t *receivers = args->recvs;
+
+  struct margin_results *results = malloc(sizeof(*results) * receivers_n);
+  struct margin_recv receiver;
+
+  if (!status)
+  {
+    results[0].test_status = MARGIN_TEST_ASPM;
+  }
+
+  if (status)
+  {
+    for (uint8_t i = 0; i < receivers_n; i++)
+    {
+      receiver.dev = (receivers[i] == 6 ? up_port : down_port);
+      receiver.recvn = receivers[i];
+      margin_receiver(&receiver, args, &(results[i]));
+    }
+
+    margin_restore_dev(down_port);
+    margin_restore_dev(up_port);
+  }
+
+  *recvs_n = receivers_n;
+  return results;
+}
+
+void margin_free_results(struct margin_results *results, uint8_t results_n)
+{
+  for (uint8_t i = 0; i < results_n; i++)
+  {
+    if (results[i].test_status == MARGIN_TEST_OK)
+      free(results[i].lanes);
+  }
+  free(results);
+}
diff --git a/lmr_lib/margin.h b/lmr_lib/margin.h
new file mode 100644
index 0000000..bb57a76
--- /dev/null
+++ b/lmr_lib/margin.h
@@ -0,0 +1,197 @@ 
+#ifndef _MARGIN_H
+#define _MARGIN_H
+
+#include "margin_hw.h"
+
+#define MARGIN_STEP_MS 1000
+
+union margin_payload {
+  unsigned int payload : 8;
+
+  struct caps {
+    bool volt_support : 1;
+    bool ind_up_down_volt : 1;
+    bool ind_left_right_tim : 1;
+    bool sample_report_method : 1;
+    bool ind_error_sampler : 1;
+  } caps;
+
+  unsigned int timing_steps : 6;
+  unsigned int voltage_steps : 7;
+  unsigned int offset : 7;
+  unsigned int max_lanes : 5;
+  unsigned int sample_rate : 6;
+
+  struct step_resp {
+    unsigned int err_count : 6;
+    unsigned int status : 2;
+  } step_resp;
+
+  struct step_tim {
+    unsigned int steps : 6;
+    bool go_left : 1;
+  } step_tim;
+
+  struct step_volt {
+    unsigned int steps : 7;
+    bool go_down : 1;
+  } step_volt;
+
+} __attribute__((packed));
+
+union margin_cmd
+{
+  unsigned int cmd : 16;
+
+  struct fields {
+    unsigned int recvn : 3;
+    unsigned int type : 3;
+    unsigned int reserved : 2;
+    union margin_payload payload;
+  } fields;
+
+} __attribute__((packed));
+
+/*Receiver structure with Lane Margining capabilities fields*/
+struct margin_recv {
+  struct margin_dev *dev;
+  uint8_t recvn; /*Receiver Number*/
+  bool lane_reversal;
+
+  bool ind_error_sampler;
+  bool sample_report_method;
+  bool ind_left_right_tim;
+  bool ind_up_down_volt;
+  bool volt_support;
+
+  uint8_t max_lanes;
+  uint8_t parallel_lanes;
+
+  uint8_t timing_steps;
+  uint8_t timing_offset;
+
+  uint8_t volt_steps;
+  uint8_t volt_offset;
+
+  uint8_t error_limit;
+
+  uint8_t sample_rate_v;
+  uint8_t sample_rate_t;
+};
+
+/*Margining Fail reason*/
+enum margin_fail_status {
+  MARGIN_NAK = 0, /*NAK/Set up for margin*/
+  MARGIN_LIM,     /*Too many errors (device limit)*/
+  MARGIN_THR      /*Test threshold has been reached*/
+};
+
+enum margin_dir {
+  VOLT_UP = 0,
+  VOLT_DOWN,
+  TIM_LEFT,
+  TIM_RIGHT
+};
+
+/*Margining results of one lane of the receiver*/
+struct margin_res_lane {
+  uint8_t lane;
+
+  uint8_t steps[4];
+  enum margin_fail_status statuses[4];
+};
+
+enum margin_test_status {
+  MARGIN_TEST_OK = 0,
+  MARGIN_TEST_READY_BIT,
+  MARGIN_TEST_CAPS,
+
+  // Couldn't run test
+  MARGIN_TEST_PREREQS,
+  MARGIN_TEST_ARGS_LANES,
+  MARGIN_TEST_ARGS_RECVS,
+  MARGIN_TEST_ASPM
+};
+
+/*All lanes Receiver results*/
+struct margin_results {
+  uint8_t recvn; /*Receiver Number*/
+  bool ind_left_right_tim;
+  bool volt_support;
+  bool ind_up_down_volt;
+  bool lane_reversal;
+  uint8_t link_speed;
+
+  enum margin_test_status test_status;
+
+  /*Used to convert steps to physical quantity.
+  Calculated from MaxOffset and NumSteps*/
+  double tim_coef;
+  double volt_coef;
+
+  uint8_t lanes_n;
+  struct margin_res_lane *lanes;
+};
+
+/*pcilmr parameters*/
+struct margin_args {
+  int8_t steps_t;        // -1 == use NumTimingSteps
+  int8_t steps_v;        // -1 == use NumVoltageSteps
+  int8_t parallel_lanes; // [1; MaxLanes + 1]
+  uint8_t error_limit;   // [0; 63]
+  uint8_t recvs[6];      // Receivers Numbers
+  int8_t recvs_n;        // -1 == margin all available receivers
+  uint8_t lanes[32];
+  int8_t lanes_n; // -1 == margin all available lanes
+  bool run_margin;
+  uint8_t verbosity; // 0 - basic; 1 - add info about remaining time and lanes in progress during margining
+
+  uint64_t *steps_margin_remaining;
+};
+
+struct margin_lanes_data {
+  struct margin_recv *recv;
+
+  struct margin_res_lane *results;
+  uint8_t *lanes_numbers;
+  uint8_t lanes_n;
+
+  bool ind;
+  enum margin_dir dir;
+
+  uint8_t steps_lane_done;
+  uint8_t steps_lane_total;
+  uint64_t *steps_margin_remaining;
+
+  uint8_t verbosity;
+};
+
+union margin_cmd margin_make_cmd(uint8_t payload, uint8_t type, uint8_t recvn);
+
+/*Read Receiver Lane Margining capabilities.
+dev, recvn and lane_reversal fields must be initialized*/
+bool margin_read_params(struct margin_recv *recv);
+
+bool margin_report_cmd(struct margin_dev *dev, uint8_t lane, 
+                       union margin_cmd cmd, union margin_payload *result);
+
+bool margin_set_cmd(struct margin_dev *dev, uint8_t lane, union margin_cmd cmd);
+
+/*Uses Lane numbers from margin_res_lane structs.
+Margin all lanes_n lanes simultaneously*/
+void margin_lanes(struct margin_lanes_data arg);
+
+/*Awaits that Receiver is prepared through prep_dev function.
+recv fields dev and recvn must be initialized*/
+bool margin_receiver(struct margin_recv *recv, struct margin_args *args, struct margin_results *results);
+
+enum margin_test_status margin_process_args(struct margin_dev *dev, struct margin_args *args);
+
+/*Awaits that args are prepared through process_args.
+Returns number of margined Receivers through recvs_n*/
+struct margin_results *margin_link(struct margin_dev *down_port, struct margin_dev *up_port, 
+                                   struct margin_args *args, uint8_t *recvs_n);
+
+void margin_free_results(struct margin_results *results, uint8_t results_n);
+
+#endif