Re: [PATCH 4/5] PCI/ACPI: Centralize pcie_ports_native checking

From: Kuppuswamy, Sathyanarayanan
Date: Wed Nov 25 2020 - 22:21:00 EST




On 11/25/20 5:18 PM, Bjorn Helgaas wrote:
From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>

If the user booted with "pcie_ports=native", we take control of the PCIe
features unconditionally, regardless of what _OSC says.

Centralize the testing of pcie_ports_native in acpi_pci_root_create(),
where we interpret the _OSC results, so other places only have to check
host_bridge->native_X and we don't have to sprinkle tests of
pcie_ports_native everywhere.

[bhelgaas: commit log, rework OSC_PCI_EXPRESS_CONTROL_MASKS, logging]
Link: https://lore.kernel.org/r/bc87c9e675118960949043a832bed86bc22becbd.1603766889.git.sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/acpi/pci_root.c | 19 +++++++++++++++++++
drivers/pci/hotplug/pciehp_core.c | 2 +-
drivers/pci/pci-acpi.c | 3 ---
drivers/pci/pcie/aer.c | 2 +-
drivers/pci/pcie/portdrv_core.c | 9 +++------
5 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 6db071038fd5..36142ed7b8f8 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -882,6 +882,8 @@ static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
flag = 0; \
} while (0)
+#define FLAG(x) ((x) ? '+' : '-')
+
struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
struct acpi_pci_root_ops *ops,
struct acpi_pci_root_info *info,
@@ -930,6 +932,23 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
OSC_OWNER(ctrl, OSC_PCI_EXPRESS_LTR_CONTROL, host_bridge->native_ltr);
OSC_OWNER(ctrl, OSC_PCI_EXPRESS_DPC_CONTROL, host_bridge->native_dpc);
+ if (pcie_ports_native) {
+ dev_info(&root->device->dev, "Taking control of PCIe-related features because \"pcie_ports=native\" specified; may conflict with firmware\n");
+ host_bridge->native_pcie_hotplug = 1;
+ host_bridge->native_aer = 1;
+ host_bridge->native_pme = 1;
+ host_bridge->native_ltr = 1;
+ host_bridge->native_dpc = 1;
+ }
Won't it be better if its merged with above OSC_OWNER() calls? If pcie_ports_native
is set, then above OSC_OWNER() calls for PCIe related features are redundant. Let me
know.
+
+ dev_info(&root->device->dev, "OS native features: SHPCHotplug%c PCIeHotplug%c PME%c AER%c DPC%c LTR%c\n",
+ FLAG(host_bridge->native_shpc_hotplug),
+ FLAG(host_bridge->native_pcie_hotplug),
+ FLAG(host_bridge->native_pme),
+ FLAG(host_bridge->native_aer),
+ FLAG(host_bridge->native_dpc),
+ FLAG(host_bridge->native_ltr));
+
/*
* Evaluate the "PCI Boot Configuration" _DSM Function. If it
* exists and returns 0, we must preserve any PCI resource
diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index ad3393930ecb..d1831e6bf60a 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -256,7 +256,7 @@ static bool pme_is_native(struct pcie_device *dev)
const struct pci_host_bridge *host;
host = pci_find_host_bridge(dev->port->bus);
- return pcie_ports_native || host->native_pme;
+ return host->native_pme;
}
static void pciehp_disable_interrupt(struct pcie_device *dev)
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index bf03648c2072..a84f75ec6df8 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -800,9 +800,6 @@ bool pciehp_is_native(struct pci_dev *bridge)
if (!(slot_cap & PCI_EXP_SLTCAP_HPC))
return false;
- if (pcie_ports_native)
- return true;
-
host = pci_find_host_bridge(bridge->bus);
return host->native_pcie_hotplug;
}
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 65dff5f3457a..79bb441139c2 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -219,7 +219,7 @@ int pcie_aer_is_native(struct pci_dev *dev)
if (!dev->aer_cap)
return 0;
- return pcie_ports_native || host->native_aer;
+ return host->native_aer;
}
int pci_enable_pcie_error_reporting(struct pci_dev *dev)
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 50a9522ab07d..2a1190e8db60 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -208,8 +208,7 @@ static int get_port_device_capability(struct pci_dev *dev)
struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
int services = 0;
- if (dev->is_hotplug_bridge &&
- (pcie_ports_native || host->native_pcie_hotplug)) {
+ if (host->native_pcie_hotplug && dev->is_hotplug_bridge) {
May be this reordering can be split into a different patch ?
services |= PCIE_PORT_SERVICE_HP;
/*
@@ -221,8 +220,7 @@ static int get_port_device_capability(struct pci_dev *dev)
}
#ifdef CONFIG_PCIEAER
- if (dev->aer_cap && pci_aer_available() &&
- (pcie_ports_native || host->native_aer)) {
+ if (host->native_aer && dev->aer_cap && pci_aer_available()) {
same as above.
services |= PCIE_PORT_SERVICE_AER;
/*
@@ -238,8 +236,7 @@ static int get_port_device_capability(struct pci_dev *dev)
* Event Collectors can also generate PMEs, but we don't handle
* those yet.
*/
- if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT &&
- (pcie_ports_native || host->native_pme)) {
+ if (host->native_pme && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
services |= PCIE_PORT_SERVICE_PME;
/*


--
Sathyanarayanan Kuppuswamy
Linux Kernel Developer