[PATCH] PCI: Decode PCIe 64 GT/s link speed
From: Gustavo Pimentel
Date: Wed Nov 18 2020 - 17:49:50 EST
PCIe r6.0, sec 7.5.3.18, defines a new 64.0 GT/s bit in the Supported
Link Speeds Vector of Link Capabilities 2.
This does not affect the speed of the link, which should be negotiated
automatically by the hardware; it only adds decoding when showing the
speed to the user.
This patch adds the decoding of this new speed, previously, reading the
speed of a link operating at this speed showed "Unknown speed" instead
of "64.0 GT/s".
Signed-off-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
---
drivers/pci/pci.h | 6 ++++--
drivers/pci/probe.c | 3 ++-
include/linux/pci.h | 1 +
include/uapi/linux/pci_regs.h | 4 ++++
4 files changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index f86cae9..81bf905 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -294,7 +294,8 @@ void pci_bus_put(struct pci_bus *bus);
/* 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_64_0GB ? PCIE_SPEED_64_0GT : \
+ (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 : \
@@ -303,7 +304,8 @@ void pci_bus_put(struct pci_bus *bus);
/* PCIe speed to Mb/s reduced by encoding overhead */
#define PCIE_SPEED2MBS_ENC(speed) \
- ((speed) == PCIE_SPEED_32_0GT ? 32000*128/130 : \
+ ((speed) == PCIE_SPEED_64_0GT ? 64000*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 : \
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 4289030..fe2e00f 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -677,7 +677,7 @@ const unsigned char pcie_link_speed[] = {
PCIE_SPEED_8_0GT, /* 3 */
PCIE_SPEED_16_0GT, /* 4 */
PCIE_SPEED_32_0GT, /* 5 */
- PCI_SPEED_UNKNOWN, /* 6 */
+ PCIE_SPEED_64_0GT, /* 6 */
PCI_SPEED_UNKNOWN, /* 7 */
PCI_SPEED_UNKNOWN, /* 8 */
PCI_SPEED_UNKNOWN, /* 9 */
@@ -719,6 +719,7 @@ const char *pci_speed_string(enum pci_bus_speed speed)
"8.0 GT/s PCIe", /* 0x16 */
"16.0 GT/s PCIe", /* 0x17 */
"32.0 GT/s PCIe", /* 0x18 */
+ "64.0 GT/s PCIe", /* 0x19 */
};
if (speed < ARRAY_SIZE(speed_strings))
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 22207a7..e007bc3 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -281,6 +281,7 @@ enum pci_bus_speed {
PCIE_SPEED_8_0GT = 0x16,
PCIE_SPEED_16_0GT = 0x17,
PCIE_SPEED_32_0GT = 0x18,
+ PCIE_SPEED_64_0GT = 0x19,
PCI_SPEED_UNKNOWN = 0xff,
};
diff --git a/include/uapi/linux/pci_regs.h b/include/uapi/linux/pci_regs.h
index a95d55f..fe9d5db 100644
--- a/include/uapi/linux/pci_regs.h
+++ b/include/uapi/linux/pci_regs.h
@@ -531,6 +531,7 @@
#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_SLS_32_0GB 0x00000005 /* LNKCAP2 SLS Vector bit 4 */
+#define PCI_EXP_LNKCAP_SLS_64_0GB 0x00000006 /* LNKCAP2 SLS Vector bit 5 */
#define PCI_EXP_LNKCAP_MLW 0x000003f0 /* Maximum Link Width */
#define PCI_EXP_LNKCAP_ASPMS 0x00000c00 /* ASPM Support */
#define PCI_EXP_LNKCAP_ASPM_L0S 0x00000400 /* ASPM L0s Support */
@@ -562,6 +563,7 @@
#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_CLS_32_0GB 0x0005 /* Current Link Speed 32.0GT/s */
+#define PCI_EXP_LNKSTA_CLS_64_0GB 0x0006 /* Current Link Speed 64.0GT/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 */
@@ -670,6 +672,7 @@
#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_SLS_32_0GB 0x00000020 /* Supported Speed 32GT/s */
+#define PCI_EXP_LNKCAP2_SLS_64_0GB 0x00000040 /* Supported Speed 64GT/s */
#define PCI_EXP_LNKCAP2_CROSSLINK 0x00000100 /* Crosslink supported */
#define PCI_EXP_LNKCTL2 48 /* Link Control 2 */
#define PCI_EXP_LNKCTL2_TLS 0x000f
@@ -678,6 +681,7 @@
#define PCI_EXP_LNKCTL2_TLS_8_0GT 0x0003 /* Supported Speed 8GT/s */
#define PCI_EXP_LNKCTL2_TLS_16_0GT 0x0004 /* Supported Speed 16GT/s */
#define PCI_EXP_LNKCTL2_TLS_32_0GT 0x0005 /* Supported Speed 32GT/s */
+#define PCI_EXP_LNKCTL2_TLS_64_0GT 0x0006 /* Supported Speed 64GT/s */
#define PCI_EXP_LNKCTL2_ENTER_COMP 0x0010 /* Enter Compliance */
#define PCI_EXP_LNKCTL2_TX_MARGIN 0x0380 /* Transmit Margin */
#define PCI_EXP_LNKCTL2_HASD 0x0020 /* HW Autonomous Speed Disable */
--
2.7.4