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SubjectRe: [PATCH] PCI: Decode PCIe 64 GT/s link speed
On Wed, Nov 18, 2020 at 11:49:20PM +0100, Gustavo Pimentel wrote:
> 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@synopsys.com>

Applied with Krzysztof's reviewed-by to pci/enumeration for v5.11,
thanks!

> ---
> 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
>

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