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Message-ID: <d1571702-b1bb-b956-c1ad-7eb917eae82e@linux.intel.com>
Date: Fri, 17 Jan 2020 17:10:00 -0800
From: Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@...ux.intel.com>
To: Bjorn Helgaas <helgaas@...nel.org>
Cc: linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org,
ashok.raj@...el.com
Subject: Re: [PATCH v12 0/8] Add Error Disconnect Recover (EDR) support
HI Bjorn,
On 1/17/20 4:18 PM, Bjorn Helgaas wrote:
> On Sun, Jan 12, 2020 at 02:43:54PM -0800, sathyanarayanan.kuppuswamy@...ux.intel.com wrote:
>> From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@...ux.intel.com>
>>
>> This patchset adds support for following features:
>>
>> 1. Error Disconnect Recover (EDR) support.
>> 2. _OSC based negotiation support for DPC.
>>
>> You can find EDR spec in the following link.
>>
>> https://members.pcisig.com/wg/PCI-SIG/document/12614
> When you update this, please incorporate the changes I've made below..
Yes, I will add these changes to my next update.
>
> diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
> index 134e20474dfd..0cb9df5462c3 100644
> --- a/drivers/acpi/pci_root.c
> +++ b/drivers/acpi/pci_root.c
> @@ -491,7 +491,13 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
> control |= OSC_PCI_EXPRESS_AER_CONTROL;
> }
>
> - if (IS_ENABLED(CONFIG_PCIE_DPC))
> + /*
> + * Per the Downstream Port Containment Related Enhancements ECN to
> + * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
> + * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
> + * and EDR.
> + */
> + if (IS_ENABLED(CONFIG_PCIE_DPC) && IS_ENABLED(CONFIG_PCIE_EDR))
> control |= OSC_PCI_EXPRESS_DPC_CONTROL;
>
> requested = control;
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index 13086518de27..547089361d4d 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -103,8 +103,7 @@ int acpi_get_rc_resources(struct device *dev, const char *hid, u16 segment,
> }
> #endif
>
> -#if defined(CONFIG_PCIE_DPC) && defined(CONFIG_ACPI)
> -
> +#if defined(CONFIG_PCIE_DPC)
> /*
> * _DSM wrapper function to enable/disable DPC port.
> * @dpc : DPC device structure
> @@ -124,14 +123,15 @@ int acpi_enable_dpc_port(struct pci_dev *pdev, acpi_handle handle, bool enable)
> argv4.package.count = 1;
> argv4.package.elements = &req;
>
> - /* As per PCI firmware specification r3.2 Downstream Port Containment
> - * Related Enhancements ECN, sec 4.6.12, EDR_PORT_ENABLE_DSM is
> - * optional and hence if its not implemented return success.
> + /*
> + * Per the Downstream Port Containment Related Enhancements ECN to
> + * the PCI Firmware Specification r3.2, sec 4.6.12,
> + * EDR_PORT_ENABLE_DSM is optional. Return success if it's not
> + * implemented.
> */
> - obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 5,
> - EDR_PORT_ENABLE_DSM, &argv4);
> + obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 5, EDR_PORT_ENABLE_DSM, &argv4);
> if (!obj)
> - return status;
> + return 0;
>
> if (obj->type != ACPI_TYPE_INTEGER || obj->integer.value != enable)
> status = -EIO;
> @@ -152,8 +152,7 @@ struct pci_dev *acpi_locate_dpc_port(struct pci_dev *pdev, acpi_handle handle)
> union acpi_object *obj;
> u16 port;
>
> - obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 5,
> - EDR_PORT_LOCATE_DSM, NULL);
> + obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 5, EDR_PORT_LOCATE_DSM, NULL);
This line goes over 80 chars, do you still want to keep them in same line ?
> if (!obj)
> return pci_dev_get(pdev);
>
> @@ -165,8 +164,8 @@ struct pci_dev *acpi_locate_dpc_port(struct pci_dev *pdev, acpi_handle handle)
> /*
> * Firmware returns DPC port BDF details in following format:
> * 15:8 = bus
> - * 7:3 = device
> - * 2:0 = function
> + * 7:3 = device
> + * 2:0 = function
> */
> port = obj->integer.value;
>
> @@ -181,11 +180,11 @@ struct pci_dev *acpi_locate_dpc_port(struct pci_dev *pdev, acpi_handle handle)
> * @dpc : DPC device structure.
> * @status: Status of EDR event.
> */
> -int acpi_send_edr_status(struct pci_dev *pdev, acpi_handle handle, u16 status)
> +int acpi_send_edr_status(struct pci_dev *pdev, acpi_handle handle, u16 status)
> {
> u32 ost_status;
>
> - pci_dbg(pdev, "Sending EDR status :%x\n", status);
> + pci_dbg(pdev, "Sending EDR status: %#x\n", status);
>
> ost_status = PCI_DEVID(pdev->bus->number, pdev->devfn);
> ost_status = (ost_status << 16) | status;
> @@ -198,8 +197,7 @@ int acpi_send_edr_status(struct pci_dev *pdev, acpi_handle handle, u16 status)
>
> return 0;
> }
> -
> -#endif /* CONFIG_PCIE_DPC && CONFIG_ACPI */
> +#endif /* CONFIG_PCIE_DPC */
>
> phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
> {
> diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
> index 2db8a3109cb5..772b1f4cb19e 100644
> --- a/drivers/pci/pcie/Kconfig
> +++ b/drivers/pci/pcie/Kconfig
> @@ -143,10 +143,10 @@ config PCIE_BW
>
> config PCIE_EDR
> bool "PCI Express Error Disconnect Recover support"
> - default n
> depends on PCIE_DPC && ACPI
> help
> - This options adds Error Disconnect Recover support as specified
> - in PCI firmware specification v3.2 Downstream Port Containment
> - Related Enhancements ECN. Enable this if you want to support hybrid
> - DPC model which uses both firmware and OS to implement DPC.
> + This option adds Error Disconnect Recover support as specified
> + in the Downstream Port Containment Related Enhancements ECN to
> + the PCI Firmware Specification r3.2. Enable this if you want to
> + support hybrid DPC model which uses both firmware and OS to
> + implement DPC.
> diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
> index 49e020d46ea1..292ce4b69e7a 100644
> --- a/drivers/pci/pcie/dpc.c
> +++ b/drivers/pci/pcie/dpc.c
> @@ -79,7 +79,7 @@ void pci_save_dpc_state(struct pci_dev *dev)
>
> /*
> * If DPC is controlled by firmware then save/restore tasks are also
> - * controller by firmware. So skip rest of the function if DPC is
> + * controlled by firmware. So skip rest of the function if DPC is
> * controlled by firmware.
> */
> if (dpc->edr_enabled)
> @@ -108,7 +108,7 @@ void pci_restore_dpc_state(struct pci_dev *dev)
>
> /*
> * If DPC is controlled by firmware then save/restore tasks are also
> - * controller by firmware. So skip rest of the function if DPC is
> + * controlled by firmware. So skip rest of the function if DPC is
> * controlled by firmware.
> */
> if (dpc->edr_enabled)
> @@ -331,14 +331,13 @@ static void dpc_error_resume(struct pci_dev *dev)
> }
>
> #ifdef CONFIG_ACPI
> -
> static void edr_handle_event(acpi_handle handle, u32 event, void *data)
> {
> - struct dpc_dev *dpc = (struct dpc_dev *) data;
> + struct dpc_dev *dpc = data;
> struct pci_dev *pdev = dpc->dev->port;
> u16 status;
>
> - pci_info(pdev, "ACPI event %x received\n", event);
> + pci_info(pdev, "ACPI event %#x received\n", event);
>
> if (event != ACPI_NOTIFY_DISCONNECT_RECOVER)
> return;
> @@ -375,7 +374,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
> pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS,
> &status);
> if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) {
> - pci_err(pdev, "Invalid DPC trigger %x\n", status);
> + pci_err(pdev, "Invalid DPC trigger %#010x\n", status);
> goto edr_unlock;
> }
> dpc_process_error(dpc);
> @@ -391,7 +390,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
> status = 0x81;
>
> /* Use ACPI handle of DPC event device for sending EDR status */
> - dpc = (struct dpc_dev *) data;
> + dpc = data;
>
> acpi_send_edr_status(pdev, dpc->adev->handle, status);
>
> @@ -400,7 +399,6 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
> done:
> pci_dev_put(pdev);
> }
> -
> #endif
>
> #define FLAG(x, y) (((x) & (y)) ? '+' : '-')
> @@ -426,11 +424,12 @@ static int dpc_probe(struct pcie_device *dev)
> mutex_init(&dpc->edr_lock);
>
> /*
> - * As per PCIe spec r5.0, implementation note titled "Determination
> + * PCIe r5.0, sec 6.2.10, implementation note titled "Determination
> * of DPC Control", to avoid conflicts over whether platform
> * firmware or the operating system have control of DPC, it is
> - * recommended that platform firmware and operating systems always link
> - * the control of DPC to the control of Advanced Error Reporting.
> + * recommended that platform firmware and operating systems always
> + * link the control of DPC to the control of Advanced Error
> + * Reporting.
> *
> * So use AER FF mode check API pcie_aer_get_firmware_first() to decide
> * whether DPC is controlled by software or firmware.
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 0b7c63c7888d..d0739e90f4e7 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -511,8 +511,8 @@ struct pci_host_bridge {
> unsigned int native_pme:1; /* OS may use PCIe PME */
> unsigned int native_ltr:1; /* OS may use PCIe LTR */
> unsigned int native_dpc:1; /* OS may use PCIe DPC */
> -
> unsigned int preserve_config:1; /* Preserve FW resource setup */
> +
> /* Resource alignment requirements */
> resource_size_t (*align_resource)(struct pci_dev *dev,
> const struct resource *res,
>
--
Sathyanarayanan Kuppuswamy
Linux kernel developer
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