[PATCH v2] lspci: Add L1 PM Substate capability reporting

["David E. Box" <david.e.box@xxxxxxxxxxxxxxx>]

From: David Box <david.e.box@xxxxxxxxxxxxxxx>

The capabilities are several L1 substates that can enable lower power
consumption when a PCIe Link is idle.

v2: fixed white space issues

Signed-off-by: David Box <david.e.box@xxxxxxxxxxxxxxx>
---
 lib/header.h |    1 +
 ls-ecaps.c   |   53 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+)

diff --git a/lib/header.h b/lib/header.h
index 69518fd..6608003 100644
--- a/lib/header.h
+++ b/lib/header.h
@@ -226,6 +226,7 @@
 #define PCI_EXT_CAP_ID_SRIOV	0x10	/* Single Root I/O Virtualization */
 #define PCI_EXT_CAP_ID_TPH	0x17	/* Transaction processing hints */
 #define PCI_EXT_CAP_ID_LTR	0x18	/* Latency Tolerance Reporting */
+#define PCI_EXT_CAP_ID_L1PM	0x1e	/* L1 PM Substates */
 
 /*** Definitions of capabilities ***/
 
diff --git a/ls-ecaps.c b/ls-ecaps.c
index 161c275..9f06ffe 100644
--- a/ls-ecaps.c
+++ b/ls-ecaps.c
@@ -448,6 +448,56 @@ cap_evendor(struct device *d, int where)
     BITS(hdr, 20, 12));
 }
 
+static void
+cap_l1pm(struct device *d, int where)
+{
+  u32 l1_cap;
+  int power_on_scale;
+
+  printf("L1 PM Substates\n");
+
+  if (verbose < 2)
+     return;
+
+  if (!config_fetch(d, where + 4, 4)) {
+     printf("\t\t<unreadable>\n");
+     return;
+  }
+
+  l1_cap = get_conf_long(d, where + 4);
+
+  printf("\t\tL1SubCap: ");
+  printf("PCI-PM_L1.2%c, PCI-PM_L1.1%c, ASPM_L1.2%c, ASPM_L1.1%c, L1_PM_Substates%c\n",
+     FLAG(l1_cap, 1),
+     FLAG(l1_cap, 2),
+     FLAG(l1_cap, 4),
+     FLAG(l1_cap, 8),
+     FLAG(l1_cap, 16));
+
+  if (BITS(l1_cap, 0, 1) || BITS(l1_cap, 2, 1)) {
+     printf("\t\t\t  PortCommonModeRestoreTime=%dus, ",
+        BITS(l1_cap, 8,8));
+
+     power_on_scale = BITS(l1_cap, 16, 2);
+
+     printf("PortTPowerOnTime=");
+     switch (power_on_scale) {
+     case 0:
+        printf("%dus\n", BITS(l1_cap, 19, 5) * 2);
+        break;
+     case 1:
+        printf("%dus\n", BITS(l1_cap, 19, 5) * 10);
+        break;
+     case 2:
+        printf("%dus\n", BITS(l1_cap, 19, 5) * 100);
+        break;
+     default:
+        printf("<error>\n");
+        break;
+     }
+  }
+}
+
 void
 show_ext_caps(struct device *d)
 {
@@ -526,6 +576,9 @@ show_ext_caps(struct device *d)
 	  case PCI_EXT_CAP_ID_LTR:
 	    cap_ltr(d, where);
 	    break;
+	  case PCI_EXT_CAP_ID_L1PM:
+	    cap_l1pm(d, where);
+	    break;
 	  default:
 	    printf("#%02x\n", id);
 	    break;
-- 
1.7.10.4

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