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From: Jay Fang <f.fangjian@huawei.com>
Date: Mon, 12 Mar 2018 17:13:32 +0800
Subject: PCI: Add decoding for 16 GT/s link speed
Patch-mainline: v4.17-rc1
Git-commit: 1acfb9b7ee0b1881bb8e875b6757976e48293ec4
References: bsc#1103990 FATE#326006

PCIe 4.0 defines the 16.0 GT/s link speed.  Links can run at that speed
without any Linux changes, but previously their sysfs "max_link_speed" and
"current_link_speed" files contained "Unknown speed", not the expected
"16.0 GT/s".

Add decoding for the new 16 GT/s link speed.

Signed-off-by: Jay Fang <f.fangjian@huawei.com>
[bhelgaas: add PCI_EXP_LNKCAP2_SLS_16_0GB]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Dongdong Liu <liudongdong3@huawei.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/pci/pci-sysfs.c       |    6 ++++++
 drivers/pci/probe.c           |    2 +-
 drivers/pci/slot.c            |    1 +
 include/linux/pci.h           |    1 +
 include/uapi/linux/pci_regs.h |    7 +++++--
 5 files changed, 14 insertions(+), 3 deletions(-)

--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -167,6 +167,9 @@ static ssize_t max_link_speed_show(struc
 		return -EINVAL;
 
 	switch (linkcap & PCI_EXP_LNKCAP_SLS) {
+	case PCI_EXP_LNKCAP_SLS_16_0GB:
+		speed = "16 GT/s";
+		break;
 	case PCI_EXP_LNKCAP_SLS_8_0GB:
 		speed = "8 GT/s";
 		break;
@@ -212,6 +215,9 @@ static ssize_t current_link_speed_show(s
 		return -EINVAL;
 
 	switch (linkstat & PCI_EXP_LNKSTA_CLS) {
+	case PCI_EXP_LNKSTA_CLS_16_0GB:
+		speed = "16 GT/s";
+		break;
 	case PCI_EXP_LNKSTA_CLS_8_0GB:
 		speed = "8 GT/s";
 		break;
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -560,7 +560,7 @@ const unsigned char pcie_link_speed[] =
 	PCIE_SPEED_2_5GT,		/* 1 */
 	PCIE_SPEED_5_0GT,		/* 2 */
 	PCIE_SPEED_8_0GT,		/* 3 */
-	PCI_SPEED_UNKNOWN,		/* 4 */
+	PCIE_SPEED_16_0GT,		/* 4 */
 	PCI_SPEED_UNKNOWN,		/* 5 */
 	PCI_SPEED_UNKNOWN,		/* 6 */
 	PCI_SPEED_UNKNOWN,		/* 7 */
--- a/drivers/pci/slot.c
+++ b/drivers/pci/slot.c
@@ -75,6 +75,7 @@ static const char *pci_bus_speed_strings
 	"2.5 GT/s PCIe",	/* 0x14 */
 	"5.0 GT/s PCIe",	/* 0x15 */
 	"8.0 GT/s PCIe",	/* 0x16 */
+	"16.0 GT/s PCIe",	/* 0x17 */
 };
 
 static ssize_t bus_speed_read(enum pci_bus_speed speed, char *buf)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -241,6 +241,7 @@ enum pci_bus_speed {
 	PCIE_SPEED_2_5GT		= 0x14,
 	PCIE_SPEED_5_0GT		= 0x15,
 	PCIE_SPEED_8_0GT		= 0x16,
+	PCIE_SPEED_16_0GT		= 0x17,
 	PCI_SPEED_UNKNOWN		= 0xff,
 };
 
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -518,6 +518,7 @@
 #define  PCI_EXP_LNKCAP_SLS_2_5GB 0x00000001 /* LNKCAP2 SLS Vector bit 0 */
 #define  PCI_EXP_LNKCAP_SLS_5_0GB 0x00000002 /* LNKCAP2 SLS Vector bit 1 */
 #define  PCI_EXP_LNKCAP_SLS_8_0GB 0x00000003 /* LNKCAP2 SLS Vector bit 2 */
+#define  PCI_EXP_LNKCAP_SLS_16_0GB 0x00000004 /* LNKCAP2 SLS Vector bit 3 */
 #define  PCI_EXP_LNKCAP_MLW	0x000003f0 /* Maximum Link Width */
 #define  PCI_EXP_LNKCAP_ASPMS	0x00000c00 /* ASPM Support */
 #define  PCI_EXP_LNKCAP_L0SEL	0x00007000 /* L0s Exit Latency */
@@ -545,6 +546,7 @@
 #define  PCI_EXP_LNKSTA_CLS_2_5GB 0x0001 /* Current Link Speed 2.5GT/s */
 #define  PCI_EXP_LNKSTA_CLS_5_0GB 0x0002 /* Current Link Speed 5.0GT/s */
 #define  PCI_EXP_LNKSTA_CLS_8_0GB 0x0003 /* Current Link Speed 8.0GT/s */
+#define  PCI_EXP_LNKSTA_CLS_16_0GB 0x0004 /* Current Link Speed 16.0GT/s */
 #define  PCI_EXP_LNKSTA_NLW	0x03f0	/* Negotiated Link Width */
 #define  PCI_EXP_LNKSTA_NLW_X1	0x0010	/* Current Link Width x1 */
 #define  PCI_EXP_LNKSTA_NLW_X2	0x0020	/* Current Link Width x2 */
@@ -642,8 +644,9 @@
 #define PCI_CAP_EXP_ENDPOINT_SIZEOF_V2	44	/* v2 endpoints end here */
 #define PCI_EXP_LNKCAP2		44	/* Link Capabilities 2 */
 #define  PCI_EXP_LNKCAP2_SLS_2_5GB	0x00000002 /* Supported Speed 2.5GT/s */
-#define  PCI_EXP_LNKCAP2_SLS_5_0GB	0x00000004 /* Supported Speed 5.0GT/s */
-#define  PCI_EXP_LNKCAP2_SLS_8_0GB	0x00000008 /* Supported Speed 8.0GT/s */
+#define  PCI_EXP_LNKCAP2_SLS_5_0GB	0x00000004 /* Supported Speed 5GT/s */
+#define  PCI_EXP_LNKCAP2_SLS_8_0GB	0x00000008 /* Supported Speed 8GT/s */
+#define  PCI_EXP_LNKCAP2_SLS_16_0GB	0x00000010 /* Supported Speed 16GT/s */
 #define  PCI_EXP_LNKCAP2_CROSSLINK	0x00000100 /* Crosslink supported */
 #define PCI_EXP_LNKCTL2		48	/* Link Control 2 */
 #define PCI_EXP_LNKSTA2		50	/* Link Status 2 */