[PATCH v9 3/5] ACPI/PCI: Ignore _OSC DPC negotiation result if pcie_ports_dpc_native is set.

From: Kuppuswamy Sathyanarayanan
Date: Sun Sep 27 2020 - 21:12:01 EST


pcie_ports_dpc_native is set only if user requests native handling
of PCIe DPC capability via pcie_port_setup command line option.
User input takes precedence over _OSC based control negotiation
result. So consider the _OSC negotiated result for DPC ownership
only if pcie_ports_dpc_native is unset.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
---
drivers/acpi/pci_root.c | 8 ++++++--
drivers/pci/pcie/dpc.c | 3 ++-
drivers/pci/pcie/portdrv.h | 2 --
drivers/pci/pcie/portdrv_core.c | 2 +-
include/linux/pci.h | 2 ++
5 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 9749b7abdd7e..979d03494476 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -935,8 +935,12 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
host_bridge->native_ltr);
OSC_OWNER(ctrl, OSC_PCI_EXPRESS_DPC_CONTROL,
host_bridge->native_dpc);
- }
-
+ if (pcie_ports_dpc_native)
+ dev_warn(&bus->dev, "OS forcibly taking over DPC\n");
+ else
+ OSC_OWNER(ctrl, OSC_PCI_EXPRESS_DPC_CONTROL,
+ host_bridge->native_dpc);
+ }
if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
host_bridge->native_shpc_hotplug = 0;

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index daa9a4153776..5b1025a2994d 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -280,11 +280,12 @@ void pci_dpc_init(struct pci_dev *pdev)
static int dpc_probe(struct pcie_device *dev)
{
struct pci_dev *pdev = dev->port;
+ struct pci_host_bridge *host = pci_find_host_bridge(pdev->bus);
struct device *device = &dev->device;
int status;
u16 ctl, cap;

- if (!pcie_aer_is_native(pdev) && !pcie_ports_dpc_native)
+ if (!pcie_aer_is_native(pdev) && !host->native_dpc)
return -ENOTSUPP;

status = devm_request_threaded_irq(device, dev->irq, dpc_irq,
diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
index af7cf237432a..0ac20feef24e 100644
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -25,8 +25,6 @@

#define PCIE_PORT_DEVICE_MAXSERVICES 5

-extern bool pcie_ports_dpc_native;
-
#ifdef CONFIG_PCIEAER
int pcie_aer_init(void);
int pcie_aer_is_native(struct pci_dev *dev);
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index ccd5e0ce5605..2c0278f0fdcc 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -253,7 +253,7 @@ static int get_port_device_capability(struct pci_dev *dev)
*/
if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
pci_aer_available() &&
- (pcie_ports_dpc_native || (services & PCIE_PORT_SERVICE_AER)))
+ (host->native_dpc || (services & PCIE_PORT_SERVICE_AER)))
services |= PCIE_PORT_SERVICE_DPC;

if (pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM ||
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 835530605c0d..dc03b6c65742 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1556,9 +1556,11 @@ static inline int pci_irqd_intx_xlate(struct irq_domain *d,
#ifdef CONFIG_PCIEPORTBUS
extern bool pcie_ports_disabled;
extern bool pcie_ports_native;
+extern bool pcie_ports_dpc_native;
#else
#define pcie_ports_disabled true
#define pcie_ports_native false
+#define pcie_ports_dpc_native false
#endif

#define PCIE_LINK_STATE_L0S BIT(0)
--
2.17.1