PCI/portdrv: Simplify PCIe feature permission checking

Some PCIe features (AER, DPC, hotplug, PME) can be managed by either the
platform firmware or the OS, so the host bridge driver may have to request
permission from the platform before using them.  On ACPI systems, this is
done by negotiate_os_control() in acpi_pci_root_add().

The PCIe port driver later uses pcie_port_platform_notify() and
pcie_port_acpi_setup() to figure out whether it can use these features.
But all we need is a single bit for each service, so these interfaces are
needlessly complicated.

Simplify this by adding bits in the struct pci_host_bridge to show when the
OS has permission to use each feature:

  + unsigned int native_aer:1;       /* OS may use PCIe AER */
  + unsigned int native_hotplug:1;   /* OS may use PCIe hotplug */
  + unsigned int native_pme:1;       /* OS may use PCIe PME */

These are set when we create a host bridge, and the host bridge driver can
clear the bits corresponding to any feature the platform doesn't want us to
use.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index 6fc204a524932e97f4a2743ae7076f1e12e86ad8..63b2cb77532498f070dd797b1168085dffa43c58 100644 (file)
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -871,6 +871,7 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
        struct acpi_device *device = root->device;
        int node = acpi_get_node(device->handle);
        struct pci_bus *bus;
+       struct pci_host_bridge *host_bridge;
 
        info->root = root;
        info->bridge = device;
@@ -895,9 +896,17 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
        if (!bus)
                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_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;
+
        pci_scan_child_bus(bus);
-       pci_set_host_bridge_release(to_pci_host_bridge(bus->bridge),
-                                   acpi_pci_root_release_info, info);
+       pci_set_host_bridge_release(host_bridge, acpi_pci_root_release_info,
+                                   info);
        if (node != NUMA_NO_NODE)
                dev_printk(KERN_DEBUG, &bus->dev, "on NUMA node %d\n", node);
        return bus;

diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
index e01c10c97b958d63e1e8195761305c3031507093..11fb633b866cea4a0b7f0bf750e3def6b3ab4ca2 100644 (file)
--- a/drivers/pci/pcie/Makefile
+++ b/drivers/pci/pcie/Makefile
@@ -7,7 +7,6 @@
 obj-$(CONFIG_PCIEASPM)         += aspm.o
 
 pcieportdrv-y                  := portdrv_core.o portdrv_pci.o
-pcieportdrv-$(CONFIG_ACPI)     += portdrv_acpi.o
 
 obj-$(CONFIG_PCIEPORTBUS)      += pcieportdrv.o
 

diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
index 7bfd75f9197bc5644f1b0444fc4f3dc4e5bce022..ed84e767085feca630f32e97668196dc071194a9 100644 (file)
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -123,15 +123,4 @@ static inline bool pcie_pme_no_msi(void) { return false; }
 static inline void pcie_pme_interrupt_enable(struct pci_dev *dev, bool en) {}
 #endif /* !CONFIG_PCIE_PME */
 
-#ifdef CONFIG_ACPI
-void pcie_port_acpi_setup(struct pci_dev *port, int *mask);
-
-static inline void pcie_port_platform_notify(struct pci_dev *port, int *mask)
-{
-       pcie_port_acpi_setup(port, mask);
-}
-#else /* !CONFIG_ACPI */
-static inline void pcie_port_platform_notify(struct pci_dev *port, int *mask){}
-#endif /* !CONFIG_ACPI */
-
 #endif /* _PORTDRV_H_ */

diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index bf851da97947a9ca6af2d30340647f3b45f2b4e5..5c25761cd05ef5acb1b192bb07f847c2a7bc4ba9 100644 (file)
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -206,19 +206,20 @@ legacy_irq:
  */
 static int get_port_device_capability(struct pci_dev *dev)
 {
+       struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
+       bool native;
        int services = 0;
-       int cap_mask = 0;
 
-       cap_mask = PCIE_PORT_SERVICE_PME | PCIE_PORT_SERVICE_HP;
-       if (pci_aer_available())
-               cap_mask |= PCIE_PORT_SERVICE_AER | PCIE_PORT_SERVICE_DPC;
-
-       if (pcie_ports_auto)
-               pcie_port_platform_notify(dev, &cap_mask);
+       /*
+        * If the user specified "pcie_ports=native", use the PCIe services
+        * regardless of whether the platform has given us permission.  On
+        * ACPI systems, this means we ignore _OSC.
+        */
+       native = !pcie_ports_auto;
 
-       /* Hot-Plug Capable */
-       if ((cap_mask & PCIE_PORT_SERVICE_HP) && dev->is_hotplug_bridge) {
+       if (dev->is_hotplug_bridge && (native || host->native_hotplug)) {
                services |= PCIE_PORT_SERVICE_HP;
+
                /*
                 * Disable hot-plug interrupts in case they have been enabled
                 * by the BIOS and the hot-plug service driver is not loaded.
@@ -226,20 +227,27 @@ static int get_port_device_capability(struct pci_dev *dev)
                pcie_capability_clear_word(dev, PCI_EXP_SLTCTL,
                          PCI_EXP_SLTCTL_CCIE | PCI_EXP_SLTCTL_HPIE);
        }
-       /* AER capable */
-       if ((cap_mask & PCIE_PORT_SERVICE_AER)
-           && pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR)) {
+
+       if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR) &&
+           pci_aer_available() && (native || host->native_aer)) {
                services |= PCIE_PORT_SERVICE_AER;
+
                /*
                 * Disable AER on this port in case it's been enabled by the
                 * BIOS (the AER service driver will enable it when necessary).
                 */
                pci_disable_pcie_error_reporting(dev);
        }
-       /* Root ports are capable of generating PME too */
-       if ((cap_mask & PCIE_PORT_SERVICE_PME)
-           && pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) {
+
+       /*
+        * Root ports are capable of generating PME too.  Root Complex
+        * Event Collectors can also generate PMEs, but we don't handle
+        * those yet.
+        */
+       if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT &&
+           (native || host->native_pme)) {
                services |= PCIE_PORT_SERVICE_PME;
+
                /*
                 * Disable PME interrupt on this port in case it's been enabled
                 * by the BIOS (the PME service driver will enable it when
@@ -247,7 +255,9 @@ static int get_port_device_capability(struct pci_dev *dev)
                 */
                pcie_pme_interrupt_enable(dev, false);
        }
-       if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC))
+
+       if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DPC) &&
+           pci_aer_available())
                services |= PCIE_PORT_SERVICE_DPC;
 
        return services;

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ef5377438a1e65df31790a61472e34e708a835ab..a00de697a97049e58ada87e0ff25c696b284ab89 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -540,6 +540,16 @@ struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
        INIT_LIST_HEAD(&bridge->windows);
        bridge->dev.release = pci_release_host_bridge_dev;
 
+       /*
+        * We assume we can manage these PCIe features.  Some systems may
+        * reserve these for use by the platform itself, e.g., an ACPI BIOS
+        * may implement its own AER handling and use _OSC to prevent the
+        * OS from interfering.
+        */
+       bridge->native_aer = 1;
+       bridge->native_hotplug = 1;
+       bridge->native_pme = 1;
+
        return bridge;
 }
 EXPORT_SYMBOL(pci_alloc_host_bridge);

diff --git a/include/linux/pci.h b/include/linux/pci.h
index 024a1beda008c69d21bd65fe8d1a36cc92a6021a..a04b7abc6b7ae07d6f75991ba24c35ae50eace87 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -469,6 +469,9 @@ struct pci_host_bridge {
        struct msi_controller *msi;
        unsigned int    ignore_reset_delay:1;   /* For entire hierarchy */
        unsigned int    no_ext_tags:1;          /* No Extended Tags */
+       unsigned int    native_aer:1;           /* OS may use PCIe AER */
+       unsigned int    native_hotplug:1;       /* OS may use PCIe hotplug */
+       unsigned int    native_pme:1;           /* OS may use PCIe PME */
        /* Resource alignment requirements */
        resource_size_t (*align_resource)(struct pci_dev *dev,
                        const struct resource *res,