[PATCH v5 0/4] Simplify PCIe native ownership detection logic

[PATCH v5 0/4] Simplify PCIe native ownership detection logic

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

Currently, PCIe capabilities ownership status is detected by
verifying the status of pcie_ports_native, pcie_ports_dpc_native
and _OSC negotiated results (cached in  struct pci_host_bridge
->native_* members). But this logic can be simplified, and we can
use only struct pci_host_bridge ->native_* members to detect it. 

This patchset removes the distributed checks for pcie_ports_native,
pcie_ports_dpc_native parameters.

Changes since v4:
 * Changed the patch set title (Original link: https://lkml.org/lkml/2020/5/26/1710)
 * Added AER/DPC dependency logic cleanup fixes.
 
Kuppuswamy Sathyanarayanan (4):
  ACPI/PCI: Ignore _OSC negotiation result if pcie_ports_native is set.
  ACPI/PCI: Ignore _OSC DPC negotiation result if pcie_ports_dpc_native
    is set.
  PCI/portdrv: Remove redundant pci_aer_available() check in DPC enable
    logic
  PCI/DPC: Move AER/DPC dependency checks out of DPC driver

 drivers/acpi/pci_root.c           | 28 ++++++++++++++++------------
 drivers/pci/hotplug/pciehp_core.c |  2 +-
 drivers/pci/pci-acpi.c            |  3 ---
 drivers/pci/pcie/aer.c            |  2 +-
 drivers/pci/pcie/dpc.c            |  4 +---
 drivers/pci/pcie/portdrv.h        |  2 --
 drivers/pci/pcie/portdrv_core.c   | 13 +++++--------
 drivers/pci/probe.c               |  4 +++-
 include/linux/pci.h               |  2 ++
 9 files changed, 29 insertions(+), 31 deletions(-)

-- 
2.17.1

[PATCH v5 1/4] ACPI/PCI: Ignore _OSC negotiation result if pcie_ports_native is set.

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

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

Also, since struct pci_host_bridge ->native_* members caches the
ownership status of various PCIe capabilities, use them instead
of distributed checks for pcie_ports_native.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
 drivers/acpi/pci_root.c           | 26 ++++++++++++++------------
 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 +++------
 drivers/pci/probe.c               |  4 +++-
 6 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 9e235c1a75ff..e0039ad3480a 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -914,18 +914,20 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 		goto out_release_info;
 
 	host_bridge = to_pci_host_bridge(bus->bridge);
-	if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
-		host_bridge->native_pcie_hotplug = 0;
-	if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
-		host_bridge->native_shpc_hotplug = 0;
-	if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
-		host_bridge->native_aer = 0;
-	if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
-		host_bridge->native_pme = 0;
-	if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
-		host_bridge->native_ltr = 0;
-	if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
-		host_bridge->native_dpc = 0;
+	if (!pcie_ports_native) {
+		if (!(root->osc_control_set & OSC_PCI_EXPRESS_NATIVE_HP_CONTROL))
+			host_bridge->native_pcie_hotplug = 0;
+		if (!(root->osc_control_set & OSC_PCI_SHPC_NATIVE_HP_CONTROL))
+			host_bridge->native_shpc_hotplug = 0;
+		if (!(root->osc_control_set & OSC_PCI_EXPRESS_AER_CONTROL))
+			host_bridge->native_aer = 0;
+		if (!(root->osc_control_set & OSC_PCI_EXPRESS_PME_CONTROL))
+			host_bridge->native_pme = 0;
+		if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
+			host_bridge->native_ltr = 0;
+		if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
+			host_bridge->native_dpc = 0;
+	}
 
 	/*
 	 * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
diff --git a/drivers/pci/hotplug/pciehp_core.c b/drivers/pci/hotplug/pciehp_core.c
index 312cc45c44c7..71bc6a6310bb 100644
--- a/drivers/pci/hotplug/pciehp_core.c
+++ b/drivers/pci/hotplug/pciehp_core.c
@@ -255,7 +255,7 @@ 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 d21969fba6ab..5551877a8a60 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 3acf56683915..d663bd9c7257 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..ccd5e0ce5605 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 (dev->is_hotplug_bridge && host->native_pcie_hotplug) {
 		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 (dev->aer_cap && pci_aer_available() && host->native_aer) {
 		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 (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT && host->native_pme) {
 		services |= PCIE_PORT_SERVICE_PME;
 
 		/*
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 77b8a145c39b..c8a3e0c5b4ce 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -593,12 +593,14 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge)
 	 * may implement its own AER handling and use _OSC to prevent the
 	 * OS from interfering.
 	 */
+#ifdef CONFIG_PCIEPORTBUS
 	bridge->native_aer = 1;
 	bridge->native_pcie_hotplug = 1;
-	bridge->native_shpc_hotplug = 1;
 	bridge->native_pme = 1;
 	bridge->native_ltr = 1;
 	bridge->native_dpc = 1;
+#endif
+	bridge->native_shpc_hotplug = 1;
 }
 
 struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
-- 
2.17.1

[PATCH v5 2/4] ACPI/PCI: Ignore _OSC DPC negotiation result if pcie_ports_dpc_native is set.

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

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@linux.intel.com>
---
 drivers/acpi/pci_root.c         | 2 ++
 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, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index e0039ad3480a..f90dba464ec2 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -925,6 +925,8 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 			host_bridge->native_pme = 0;
 		if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
 			host_bridge->native_ltr = 0;
+	}
+	if (!pcie_ports_native && !pcie_ports_dpc_native) {
 		if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
 			host_bridge->native_dpc = 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 83ce1cdf5676..07d4db97f5f4 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1547,9 +1547,11 @@ 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

[PATCH v5 3/4] PCI/portdrv: Remove redundant pci_aer_available() check in DPC enable logic

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

In DPC service enable logic, check for
services & PCIE_PORT_SERVICE_AER implies pci_aer_available()
is true. So there is no need to explicitly check it again.

Also, passing pcie_ports=dpc-native in kernel command line
implies DPC needs to be enabled in native mode irrespective
of AER ownership status. So checking for pci_aer_available()
without checking for pcie_ports status is incorrect.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
 drivers/pci/pcie/portdrv_core.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 2c0278f0fdcc..e257a2ca3595 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -252,7 +252,6 @@ static int get_port_device_capability(struct pci_dev *dev)
 	 * permission to use AER.
 	 */
 	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
-	    pci_aer_available() &&
 	    (host->native_dpc || (services & PCIE_PORT_SERVICE_AER)))
 		services |= PCIE_PORT_SERVICE_DPC;
 
-- 
2.17.1

[PATCH v5 4/4] PCI/DPC: Move AER/DPC dependency checks out of DPC driver

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

Currently, AER and DPC Capabilities dependency checks is
distributed between DPC and portdrv service drivers. So move
them out of DPC driver.

Also, since services & PCIE_PORT_SERVICE_AER check already
ensures AER native ownership, no need to add additional
pcie_aer_is_native() check.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
 drivers/pci/pcie/dpc.c          | 3 ---
 drivers/pci/pcie/portdrv_core.c | 1 +
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 5b1025a2994d..3efbe43764f3 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -285,9 +285,6 @@ static int dpc_probe(struct pcie_device *dev)
 	int status;
 	u16 ctl, cap;
 
-	if (!pcie_aer_is_native(pdev) && !host->native_dpc)
-		return -ENOTSUPP;
-
 	status = devm_request_threaded_irq(device, dev->irq, dpc_irq,
 					   dpc_handler, IRQF_SHARED,
 					   "pcie-dpc", pdev);
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index e257a2ca3595..ffa1d9fc458e 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -252,6 +252,7 @@ static int get_port_device_capability(struct pci_dev *dev)
 	 * permission to use AER.
 	 */
 	if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
+	    host->native_dpc &&
 	    (host->native_dpc || (services & PCIE_PORT_SERVICE_AER)))
 		services |= PCIE_PORT_SERVICE_DPC;
 
-- 
2.17.1