Re: [PATCH v12 0/8] Add Error Disconnect Recover (EDR) support
From: Kuppuswamy Sathyanarayanan
Date: Fri Jan 17 2020 - 20:12:20 EST
HI Bjorn,
On 1/17/20 4:18 PM, Bjorn Helgaas wrote:
On Sun, Jan 12, 2020 at 02:43:54PM -0800, sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx wrote:
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
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