On Tue, Jan 26, 2021 at 5:01 PM Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
>
> ACPI 6.4 introduced a new _OSC capability that is used negotiate native
> connection manager support. Connection manager is the entity that is
> responsible for tunneling over the USB4 fabric. If the platform rejects
> the native access then firmware based connection manager is used.
>
> The new _OSC also includes a set of bits that can be used to disable
> certain tunnel types such as PCIe for security reasons for instance.
>
> This implements the new USB4 _OSC so that we try to negotiate native
> USB4 support if the Thunderbolt/USB4 (CONFIG_USB4) driver is enabled.
> Drivers can determine what was negotiated by checking two new variables
> exposed in this patch.
>
> Cc: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> ---
> drivers/acpi/bus.c | 76 ++++++++++++++++++++++++++++++++++++++++++++
> include/linux/acpi.h | 10 ++++++
> 2 files changed, 86 insertions(+)
>
> diff --git a/drivers/acpi/bus.c b/drivers/acpi/bus.c
> index ca7c7b2bf56e..f7ad2d283e51 100644
> --- a/drivers/acpi/bus.c
> +++ b/drivers/acpi/bus.c
> @@ -281,6 +281,12 @@ bool osc_sb_apei_support_acked;
> bool osc_pc_lpi_support_confirmed;
> EXPORT_SYMBOL_GPL(osc_pc_lpi_support_confirmed);
>
> +/*
> + * ACPI 6.4 Operating System Capabilities for USB.
> + */
> +bool osc_sb_native_usb4_support_confirmed;
> +EXPORT_SYMBOL_GPL(osc_sb_native_usb4_support_confirmed);
> +
> static u8 sb_uuid_str[] = "0811B06E-4A27-44F9-8D60-3CBBC22E7B48";
> static void acpi_bus_osc_negotiate_platform_control(void)
> {
> @@ -317,6 +323,9 @@ static void acpi_bus_osc_negotiate_platform_control(void)
> if (IS_ENABLED(CONFIG_SCHED_MC_PRIO))
> capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_CPC_DIVERSE_HIGH_SUPPORT;
>
> + if (IS_ENABLED(CONFIG_USB4))
> + capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_NATIVE_USB4_SUPPORT;
> +
> if (!ghes_disable)
> capbuf[OSC_SUPPORT_DWORD] |= OSC_SB_APEI_SUPPORT;
> if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
> @@ -348,8 +357,74 @@ static void acpi_bus_osc_negotiate_platform_control(void)
> capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_APEI_SUPPORT;
> osc_pc_lpi_support_confirmed =
> capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_PCLPI_SUPPORT;
> + osc_sb_native_usb4_support_confirmed =
> + capbuf_ret[OSC_SUPPORT_DWORD] & OSC_SB_NATIVE_USB4_SUPPORT;
> + }
> +
> + kfree(context.ret.pointer);
> +}
> +
> +/*
> + * Native control of USB4 capabilities. If any of the tunneling bits is
> + * set it means OS is in control and we use software based connection
> + * manager.
> + */
> +u32 osc_sb_native_usb4_control;
> +EXPORT_SYMBOL_GPL(osc_sb_native_usb4_control);
> +
> +static void acpi_bus_decode_usb_osc(const char *msg, u32 bits)
> +{
> + printk(KERN_INFO PREFIX "%s USB3%c DisplayPort%c PCIe%c XDomain%c\n", msg,
> + (bits & OSC_USB_USB3_TUNNELING) ? '+' : '-',
> + (bits & OSC_USB_DP_TUNNELING) ? '+' : '-',
> + (bits & OSC_USB_PCIE_TUNNELING) ? '+' : '-',
> + (bits & OSC_USB_XDOMAIN) ? '+' : '-');
> +}
> +
> +static u8 sb_usb_uuid_str[] = "23A0D13A-26AB-486C-9C5F-0FFA525A575A";
> +static void acpi_bus_osc_negotiate_usb_control(void)
> +{
> + u32 capbuf[3];
> + struct acpi_osc_context context = {
> + .uuid_str = sb_usb_uuid_str,
> + .rev = 1,
> + .cap.length = sizeof(capbuf),
> + .cap.pointer = capbuf,
> + };
> + acpi_handle handle;
> + acpi_status status;
> + u32 control;
> +
> + if (!osc_sb_native_usb4_support_confirmed)
> + return;
> +
> + if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
> + return;
> +
> + control = OSC_USB_USB3_TUNNELING | OSC_USB_DP_TUNNELING |
> + OSC_USB_PCIE_TUNNELING | OSC_USB_XDOMAIN;
> +
> + capbuf[OSC_QUERY_DWORD] = 0;
> + capbuf[OSC_SUPPORT_DWORD] = 0;
> + capbuf[OSC_CONTROL_DWORD] = control;
> +
> + status = acpi_run_osc(handle, &context);
This is the same _OSC that is evaluated in
acpi_bus_osc_negotiate_platform_control(), right?
So shouldn't the capbuf[OSC_SUPPORT_DWORD] be whatever is negotiated
through acpi_bus_osc_negotiate_platform_control()? At least that
would be consistent with acpi_pci_osc_control_set().
And if this was done I'm not sure if the change in the previous patch
would be needed then?
> + if (ACPI_FAILURE(status))
> + return;
> +
> + if (context.ret.length != sizeof(capbuf)) {
> + printk(KERN_INFO PREFIX "USB4 _OSC: returned invalid length buffer\n");
> + goto out_free;
> }
>
> + osc_sb_native_usb4_control =
> + control & ((u32 *)context.ret.pointer)[OSC_CONTROL_DWORD];
> +
> + acpi_bus_decode_usb_osc("USB4 _OSC: OS supports", control);
> + acpi_bus_decode_usb_osc("USB4 _OSC: OS controls",
> + osc_sb_native_usb4_control);
> +
> +out_free:
> kfree(context.ret.pointer);
> }
>
> @@ -1188,6 +1263,7 @@ static int __init acpi_bus_init(void)
> * so it must be run after ACPI_FULL_INITIALIZATION
> */
> acpi_bus_osc_negotiate_platform_control();
> + acpi_bus_osc_negotiate_usb_control();
>
> /*
> * _PDC control method may load dynamic SSDT tables,
> diff --git a/include/linux/acpi.h b/include/linux/acpi.h
> index 2630c2e953f7..ac68c2d4e393 100644
> --- a/include/linux/acpi.h
> +++ b/include/linux/acpi.h
> @@ -546,9 +546,19 @@ acpi_status acpi_run_osc(acpi_handle handle, struct acpi_osc_context *context);
> #define OSC_SB_OSLPI_SUPPORT 0x00000100
> #define OSC_SB_CPC_DIVERSE_HIGH_SUPPORT 0x00001000
> #define OSC_SB_GENERIC_INITIATOR_SUPPORT 0x00002000
> +#define OSC_SB_NATIVE_USB4_SUPPORT 0x00040000
>
> extern bool osc_sb_apei_support_acked;
> extern bool osc_pc_lpi_support_confirmed;
> +extern bool osc_sb_native_usb4_support_confirmed;
> +
> +/* USB4 Capabilities */
> +#define OSC_USB_USB3_TUNNELING 0x00000001
> +#define OSC_USB_DP_TUNNELING 0x00000002
> +#define OSC_USB_PCIE_TUNNELING 0x00000004
> +#define OSC_USB_XDOMAIN 0x00000008
> +
> +extern u32 osc_sb_native_usb4_control;
>
> /* PCI Host Bridge _OSC: Capabilities DWORD 2: Support Field */
> #define OSC_PCI_EXT_CONFIG_SUPPORT 0x00000001
> --
> 2.29.2
>
