Merge branch 'pci/enumeration'

  - Add PCIe 32 GT/s speed decoding for sysfs "max_link_speed" and dmesg
    notes about available bandwidth (Yicong Yang)

  - Simplify and unify PCI bus/link speed reporting (Yicong Yang)

* pci/enumeration:
  PCI: Add PCIE_LNKCAP2_SLS2SPEED() macro
  PCI: Use pci_speed_string() for all PCI/PCI-X/PCIe strings
  PCI: Add pci_speed_string()
  PCI: Add 32 GT/s decoding in some macros

7 files changed, 67 insertions, 86 deletions

diff --git a/drivers/pci/controller/pcie-brcmstb.c b/drivers/pci/controller/pcie-brcmstb.c
index d20aabc26273..7234eb2a54c9 100644
--- a/drivers/pci/controller/pcie-brcmstb.c
+++ b/drivers/pci/controller/pcie-brcmstb.c
@@ -824,8 +824,8 @@ static int brcm_pcie_setup(struct brcm_pcie *pcie)
 	cls = FIELD_GET(PCI_EXP_LNKSTA_CLS, lnksta);
 	nlw = FIELD_GET(PCI_EXP_LNKSTA_NLW, lnksta);
 	dev_info(dev, "link up, %s x%u %s\n",
-		 PCIE_SPEED2STR(cls + PCI_SPEED_133MHz_PCIX_533),
-		 nlw, ssc_good ? "(SSC)" : "(!SSC)");
+		 pci_speed_string(pcie_link_speed[cls]), nlw,
+		 ssc_good ? "(SSC)" : "(!SSC)");
 
 	/* PCIe->SCB endian mode for BAR */
 	tmp = readl(base + PCIE_RC_CFG_VENDOR_VENDOR_SPECIFIC_REG1);
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 13f766db0684..d123d1087061 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -156,7 +156,8 @@ static ssize_t max_link_speed_show(struct device *dev,
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 
-	return sprintf(buf, "%s\n", PCIE_SPEED2STR(pcie_get_speed_cap(pdev)));
+	return sprintf(buf, "%s\n",
+		       pci_speed_string(pcie_get_speed_cap(pdev)));
 }
 static DEVICE_ATTR_RO(max_link_speed);
 
@@ -175,33 +176,15 @@ static ssize_t current_link_speed_show(struct device *dev,
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	u16 linkstat;
 	int err;
-	const char *speed;
+	enum pci_bus_speed speed;
 
 	err = pcie_capability_read_word(pci_dev, PCI_EXP_LNKSTA, &linkstat);
 	if (err)
 		return -EINVAL;
 
-	switch (linkstat & PCI_EXP_LNKSTA_CLS) {
-	case PCI_EXP_LNKSTA_CLS_32_0GB:
-		speed = "32 GT/s";
-		break;
-	case PCI_EXP_LNKSTA_CLS_16_0GB:
-		speed = "16 GT/s";
-		break;
-	case PCI_EXP_LNKSTA_CLS_8_0GB:
-		speed = "8 GT/s";
-		break;
-	case PCI_EXP_LNKSTA_CLS_5_0GB:
-		speed = "5 GT/s";
-		break;
-	case PCI_EXP_LNKSTA_CLS_2_5GB:
-		speed = "2.5 GT/s";
-		break;
-	default:
-		speed = "Unknown speed";
-	}
+	speed = pcie_link_speed[linkstat & PCI_EXP_LNKSTA_CLS];
 
-	return sprintf(buf, "%s\n", speed);
+	return sprintf(buf, "%s\n", pci_speed_string(speed));
 }
 static DEVICE_ATTR_RO(current_link_speed);
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 6c6e8c73fd8f..4aa46c7b0148 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5784,19 +5784,10 @@ enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev)
 	 * where only 2.5 GT/s and 5.0 GT/s speeds were defined.
 	 */
 	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2);
-	if (lnkcap2) { /* PCIe r3.0-compliant */
-		if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_32_0GB)
-			return PCIE_SPEED_32_0GT;
-		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_16_0GB)
-			return PCIE_SPEED_16_0GT;
-		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_8_0GB)
-			return PCIE_SPEED_8_0GT;
-		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_5_0GB)
-			return PCIE_SPEED_5_0GT;
-		else if (lnkcap2 & PCI_EXP_LNKCAP2_SLS_2_5GB)
-			return PCIE_SPEED_2_5GT;
-		return PCI_SPEED_UNKNOWN;
-	}
+
+	/* PCIe r3.0-compliant */
+	if (lnkcap2)
+		return PCIE_LNKCAP2_SLS2SPEED(lnkcap2);
 
 	pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap);
 	if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB)
@@ -5872,14 +5863,14 @@ void __pcie_print_link_status(struct pci_dev *dev, bool verbose)
 	if (bw_avail >= bw_cap && verbose)
 		pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n",
 			 bw_cap / 1000, bw_cap % 1000,
-			 PCIE_SPEED2STR(speed_cap), width_cap);
+			 pci_speed_string(speed_cap), width_cap);
 	else if (bw_avail < bw_cap)
 		pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n",
 			 bw_avail / 1000, bw_avail % 1000,
-			 PCIE_SPEED2STR(speed), width,
+			 pci_speed_string(speed), width,
 			 limiting_dev ? pci_name(limiting_dev) : "<unknown>",
 			 bw_cap / 1000, bw_cap % 1000,
-			 PCIE_SPEED2STR(speed_cap), width_cap);
+			 pci_speed_string(speed_cap), width_cap);
 }
 
 /**
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index bd46f23e3db1..6d3f75867106 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -292,22 +292,25 @@ void pci_disable_bridge_window(struct pci_dev *dev);
 struct pci_bus *pci_bus_get(struct pci_bus *bus);
 void pci_bus_put(struct pci_bus *bus);
 
-/* PCIe link information */
-#define PCIE_SPEED2STR(speed) \
-	((speed) == PCIE_SPEED_16_0GT ? "16 GT/s" : \
-	 (speed) == PCIE_SPEED_8_0GT ? "8 GT/s" : \
-	 (speed) == PCIE_SPEED_5_0GT ? "5 GT/s" : \
-	 (speed) == PCIE_SPEED_2_5GT ? "2.5 GT/s" : \
-	 "Unknown speed")
+/* PCIe link information from Link Capabilities 2 */
+#define PCIE_LNKCAP2_SLS2SPEED(lnkcap2) \
+	((lnkcap2) & PCI_EXP_LNKCAP2_SLS_32_0GB ? PCIE_SPEED_32_0GT : \
+	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_16_0GB ? PCIE_SPEED_16_0GT : \
+	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_8_0GB ? PCIE_SPEED_8_0GT : \
+	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_5_0GB ? PCIE_SPEED_5_0GT : \
+	 (lnkcap2) & PCI_EXP_LNKCAP2_SLS_2_5GB ? PCIE_SPEED_2_5GT : \
+	 PCI_SPEED_UNKNOWN)
 
 /* PCIe speed to Mb/s reduced by encoding overhead */
 #define PCIE_SPEED2MBS_ENC(speed) \
-	((speed) == PCIE_SPEED_16_0GT ? 16000*128/130 : \
+	((speed) == PCIE_SPEED_32_0GT ? 32000*128/130 : \
+	 (speed) == PCIE_SPEED_16_0GT ? 16000*128/130 : \
 	 (speed) == PCIE_SPEED_8_0GT  ?  8000*128/130 : \
 	 (speed) == PCIE_SPEED_5_0GT  ?  5000*8/10 : \
 	 (speed) == PCIE_SPEED_2_5GT  ?  2500*8/10 : \
 	 0)
 
+const char *pci_speed_string(enum pci_bus_speed speed);
 enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev);
 enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev);
 u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed,
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index f67c007edcae..77b8a145c39b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -641,6 +641,7 @@ void pci_free_host_bridge(struct pci_host_bridge *bridge)
 }
 EXPORT_SYMBOL(pci_free_host_bridge);
 
+/* Indexed by PCI_X_SSTATUS_FREQ (secondary bus mode and frequency) */
 static const unsigned char pcix_bus_speed[] = {
 	PCI_SPEED_UNKNOWN,		/* 0 */
 	PCI_SPEED_66MHz_PCIX,		/* 1 */
@@ -660,6 +661,7 @@ static const unsigned char pcix_bus_speed[] = {
 	PCI_SPEED_133MHz_PCIX_533	/* F */
 };
 
+/* Indexed by PCI_EXP_LNKCAP_SLS, PCI_EXP_LNKSTA_CLS */
 const unsigned char pcie_link_speed[] = {
 	PCI_SPEED_UNKNOWN,		/* 0 */
 	PCIE_SPEED_2_5GT,		/* 1 */
@@ -678,6 +680,44 @@ const unsigned char pcie_link_speed[] = {
 	PCI_SPEED_UNKNOWN,		/* E */
 	PCI_SPEED_UNKNOWN		/* F */
 };
+EXPORT_SYMBOL_GPL(pcie_link_speed);
+
+const char *pci_speed_string(enum pci_bus_speed speed)
+{
+	/* Indexed by the pci_bus_speed enum */
+	static const char *speed_strings[] = {
+	    "33 MHz PCI",		/* 0x00 */
+	    "66 MHz PCI",		/* 0x01 */
+	    "66 MHz PCI-X",		/* 0x02 */
+	    "100 MHz PCI-X",		/* 0x03 */
+	    "133 MHz PCI-X",		/* 0x04 */
+	    NULL,			/* 0x05 */
+	    NULL,			/* 0x06 */
+	    NULL,			/* 0x07 */
+	    NULL,			/* 0x08 */
+	    "66 MHz PCI-X 266",		/* 0x09 */
+	    "100 MHz PCI-X 266",	/* 0x0a */
+	    "133 MHz PCI-X 266",	/* 0x0b */
+	    "Unknown AGP",		/* 0x0c */
+	    "1x AGP",			/* 0x0d */
+	    "2x AGP",			/* 0x0e */
+	    "4x AGP",			/* 0x0f */
+	    "8x AGP",			/* 0x10 */
+	    "66 MHz PCI-X 533",		/* 0x11 */
+	    "100 MHz PCI-X 533",	/* 0x12 */
+	    "133 MHz PCI-X 533",	/* 0x13 */
+	    "2.5 GT/s PCIe",		/* 0x14 */
+	    "5.0 GT/s PCIe",		/* 0x15 */
+	    "8.0 GT/s PCIe",		/* 0x16 */
+	    "16.0 GT/s PCIe",		/* 0x17 */
+	    "32.0 GT/s PCIe",		/* 0x18 */
+	};
+
+	if (speed < ARRAY_SIZE(speed_strings))
+		return speed_strings[speed];
+	return "Unknown";
+}
+EXPORT_SYMBOL_GPL(pci_speed_string);
 
 void pcie_update_link_speed(struct pci_bus *bus, u16 linksta)
 {
diff --git a/drivers/pci/slot.c b/drivers/pci/slot.c
index ae4aa0e1f2f4..cc386ef2fa12 100644
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -49,45 +49,9 @@ static ssize_t address_read_file(struct pci_slot *slot, char *buf)
 				slot->number);
 }
 
-/* these strings match up with the values in pci_bus_speed */
-static const char *pci_bus_speed_strings[] = {
-	"33 MHz PCI",		/* 0x00 */
-	"66 MHz PCI",		/* 0x01 */
-	"66 MHz PCI-X",		/* 0x02 */
-	"100 MHz PCI-X",	/* 0x03 */
-	"133 MHz PCI-X",	/* 0x04 */
-	NULL,			/* 0x05 */
-	NULL,			/* 0x06 */
-	NULL,			/* 0x07 */
-	NULL,			/* 0x08 */
-	"66 MHz PCI-X 266",	/* 0x09 */
-	"100 MHz PCI-X 266",	/* 0x0a */
-	"133 MHz PCI-X 266",	/* 0x0b */
-	"Unknown AGP",		/* 0x0c */
-	"1x AGP",		/* 0x0d */
-	"2x AGP",		/* 0x0e */
-	"4x AGP",		/* 0x0f */
-	"8x AGP",		/* 0x10 */
-	"66 MHz PCI-X 533",	/* 0x11 */
-	"100 MHz PCI-X 533",	/* 0x12 */
-	"133 MHz PCI-X 533",	/* 0x13 */
-	"2.5 GT/s PCIe",	/* 0x14 */
-	"5.0 GT/s PCIe",	/* 0x15 */
-	"8.0 GT/s PCIe",	/* 0x16 */
-	"16.0 GT/s PCIe",	/* 0x17 */
-	"32.0 GT/s PCIe",	/* 0x18 */
-};
-
 static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
 {
-	const char *speed_string;
-
-	if (speed < ARRAY_SIZE(pci_bus_speed_strings))
-		speed_string = pci_bus_speed_strings[speed];
-	else
-		speed_string = "Unknown";
-
-	return sprintf(buf, "%s\n", speed_string);
+	return sprintf(buf, "%s\n", pci_speed_string(speed));
 }
 
 static ssize_t max_speed_read_file(struct pci_slot *slot, char *buf)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 7ed7c088c952..226908b4dc64 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -236,7 +236,7 @@ enum pcie_link_width {
 	PCIE_LNK_WIDTH_UNKNOWN	= 0xff,
 };
 
-/* Based on the PCI Hotplug Spec, but some values are made up by us */
+/* See matching string table in pci_speed_string() */
 enum pci_bus_speed {
 	PCI_SPEED_33MHz			= 0x00,
 	PCI_SPEED_66MHz			= 0x01,