Merge tag 'pci-v4.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:

  - detach driver before tearing down procfs/sysfs (Alex Williamson)

  - disable PCIe services during shutdown (Sinan Kaya)

  - fix ASPM oops on systems with no Root Ports (Ard Biesheuvel)

  - fix ASPM LTR_L1.2_THRESHOLD programming (Bjorn Helgaas)

  - fix ASPM Common_Mode_Restore_Time computation (Bjorn Helgaas)

  - fix portdrv MSI/MSI-X vector allocation (Dongdong Liu, Bjorn
    Helgaas)

  - report non-fatal AER errors only to the affected endpoint (Gabriele
    Paoloni)

  - distribute bus numbers, MMIO, and I/O space among hotplug bridges to
    allow more devices to be hot-added (Mika Westerberg)

  - fix pciehp races during initialization and surprise link down (Mika
    Westerberg)

  - handle surprise-removed devices in PME handling (Qiang)

  - support resizable BARs for large graphics devices (Christian König)

  - expose SR-IOV offset, stride, and VF device ID via sysfs (Filippo
    Sironi)

  - create SR-IOV virtfn/physfn sysfs links before attaching driver
    (Stuart Hayes)

  - fix SR-IOV "ARI Capable Hierarchy" restore issue (Tony Nguyen)

  - enforce Kconfig IOV/REALLOC dependency (Sascha El-Sharkawy)

  - avoid slot reset if bridge itself is broken (Jan Glauber)

  - clean up pci_reset_function() path (Jan H. Schönherr)

  - make pci_map_rom() fail if the option ROM is invalid (Changbin Du)

  - convert timers to timer_setup() (Kees Cook)

  - move PCI_QUIRKS to PCI bus Kconfig menu (Randy Dunlap)

  - constify pci_dev_type and intel_mid_pci_ops (Bhumika Goyal)

  - remove unnecessary pci_dev, pci_bus, resource, pcibios_set_master()
    declarations (Bjorn Helgaas)

  - fix endpoint framework overflows and BUG()s (Dan Carpenter)

  - fix endpoint framework issues (Kishon Vijay Abraham I)

  - avoid broken Cavium CN8xxx bus reset behavior (David Daney)

  - extend Cavium ACS capability quirks (Vadim Lomovtsev)

  - support Synopsys DesignWare RC in ECAM mode (Ard Biesheuvel)

  - turn off dra7xx clocks cleanly on shutdown (Keerthy)

  - fix Faraday probe error path (Wei Yongjun)

  - support HiSilicon STB SoC PCIe host controller (Jianguo Sun)

  - fix Hyper-V interrupt affinity issue (Dexuan Cui)

  - remove useless ACPI warning for Hyper-V pass-through devices (Vitaly
    Kuznetsov)

  - support multiple MSI on iProc (Sandor Bodo-Merle)

  - support Layerscape LS1012a and LS1046a PCIe host controllers (Hou
    Zhiqiang)

  - fix Layerscape default error response (Minghuan Lian)

  - support MSI on Tango host controller (Marc Gonzalez)

  - support Tegra186 PCIe host controller (Manikanta Maddireddy)

  - use generic accessors on Tegra when possible (Thierry Reding)

  - support V3 Semiconductor PCI host controller (Linus Walleij)

* tag 'pci-v4.15-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (85 commits)
  PCI/ASPM: Add L1 Substates definitions
  PCI/ASPM: Reformat ASPM register definitions
  PCI/ASPM: Use correct capability pointer to program LTR_L1.2_THRESHOLD
  PCI/ASPM: Account for downstream device's Port Common_Mode_Restore_Time
  PCI: xgene: Rename xgene_pcie_probe_bridge() to xgene_pcie_probe()
  PCI: xilinx: Rename xilinx_pcie_link_is_up() to xilinx_pcie_link_up()
  PCI: altera: Rename altera_pcie_link_is_up() to altera_pcie_link_up()
  PCI: Fix kernel-doc build warning
  PCI: Fail pci_map_rom() if the option ROM is invalid
  PCI: Move pci_map_rom() error path
  PCI: Move PCI_QUIRKS to the PCI bus menu
  alpha/PCI: Make pdev_save_srm_config() static
  PCI: Remove unused declarations
  PCI: Remove redundant pci_dev, pci_bus, resource declarations
  PCI: Remove redundant pcibios_set_master() declarations
  PCI/PME: Handle invalid data when reading Root Status
  PCI: hv: Use effective affinity mask
  PCI: pciehp: Do not clear Presence Detect Changed during initialization
  PCI: pciehp: Fix race condition handling surprise link down
  PCI: Distribute available resources to hotplug-capable bridges
  ...

1 files changed, 173 insertions, 14 deletions

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index ff94b69738a8..14e0ea1ff38b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -959,7 +959,21 @@ static void pci_enable_crs(struct pci_dev *pdev)
 					 PCI_EXP_RTCTL_CRSSVE);
 }
 
+static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
+					      unsigned int available_buses);
+
 /*
+ * pci_scan_bridge_extend() - Scan buses behind a bridge
+ * @bus: Parent bus the bridge is on
+ * @dev: Bridge itself
+ * @max: Starting subordinate number of buses behind this bridge
+ * @available_buses: Total number of buses available for this bridge and
+ *		     the devices below. After the minimal bus space has
+ *		     been allocated the remaining buses will be
+ *		     distributed equally between hotplug-capable bridges.
+ * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges
+ *        that need to be reconfigured.
+ *
  * If it's a bridge, configure it and scan the bus behind it.
  * For CardBus bridges, we don't scan behind as the devices will
  * be handled by the bridge driver itself.
@@ -969,7 +983,9 @@ static void pci_enable_crs(struct pci_dev *pdev)
  * them, we proceed to assigning numbers to the remaining buses in
  * order to avoid overlaps between old and new bus numbers.
  */
-int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
+static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev,
+				  int max, unsigned int available_buses,
+				  int pass)
 {
 	struct pci_bus *child;
 	int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS);
@@ -1076,9 +1092,13 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
 			child = pci_add_new_bus(bus, dev, max+1);
 			if (!child)
 				goto out;
-			pci_bus_insert_busn_res(child, max+1, 0xff);
+			pci_bus_insert_busn_res(child, max+1,
+						bus->busn_res.end);
 		}
 		max++;
+		if (available_buses)
+			available_buses--;
+
 		buses = (buses & 0xff000000)
 		      | ((unsigned int)(child->primary)     <<  0)
 		      | ((unsigned int)(child->busn_res.start)   <<  8)
@@ -1100,7 +1120,7 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
 
 		if (!is_cardbus) {
 			child->bridge_ctl = bctl;
-			max = pci_scan_child_bus(child);
+			max = pci_scan_child_bus_extend(child, available_buses);
 		} else {
 			/*
 			 * For CardBus bridges, we leave 4 bus numbers
@@ -1168,6 +1188,28 @@ out:
 
 	return max;
 }
+
+/*
+ * pci_scan_bridge() - Scan buses behind a bridge
+ * @bus: Parent bus the bridge is on
+ * @dev: Bridge itself
+ * @max: Starting subordinate number of buses behind this bridge
+ * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges
+ *        that need to be reconfigured.
+ *
+ * If it's a bridge, configure it and scan the bus behind it.
+ * For CardBus bridges, we don't scan behind as the devices will
+ * be handled by the bridge driver itself.
+ *
+ * We need to process bridges in two passes -- first we scan those
+ * already configured by the BIOS and after we are done with all of
+ * them, we proceed to assigning numbers to the remaining buses in
+ * order to avoid overlaps between old and new bus numbers.
+ */
+int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
+{
+	return pci_scan_bridge_extend(bus, dev, max, 0, pass);
+}
 EXPORT_SYMBOL(pci_scan_bridge);
 
 /*
@@ -2396,9 +2438,24 @@ void __weak pcibios_fixup_bus(struct pci_bus *bus)
        /* nothing to do, expected to be removed in the future */
 }
 
-unsigned int pci_scan_child_bus(struct pci_bus *bus)
+/**
+ * pci_scan_child_bus_extend() - Scan devices below a bus
+ * @bus: Bus to scan for devices
+ * @available_buses: Total number of buses available (%0 does not try to
+ *		     extend beyond the minimal)
+ *
+ * Scans devices below @bus including subordinate buses. Returns new
+ * subordinate number including all the found devices. Passing
+ * @available_buses causes the remaining bus space to be distributed
+ * equally between hotplug-capable bridges to allow future extension of the
+ * hierarchy.
+ */
+static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus,
+					      unsigned int available_buses)
 {
-	unsigned int devfn, pass, max = bus->busn_res.start;
+	unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0;
+	unsigned int start = bus->busn_res.start;
+	unsigned int devfn, cmax, max = start;
 	struct pci_dev *dev;
 
 	dev_dbg(&bus->dev, "scanning bus\n");
@@ -2408,7 +2465,8 @@ unsigned int pci_scan_child_bus(struct pci_bus *bus)
 		pci_scan_slot(bus, devfn);
 
 	/* Reserve buses for SR-IOV capability. */
-	max += pci_iov_bus_range(bus);
+	used_buses = pci_iov_bus_range(bus);
+	max += used_buses;
 
 	/*
 	 * After performing arch-dependent fixup of the bus, look behind
@@ -2420,19 +2478,73 @@ unsigned int pci_scan_child_bus(struct pci_bus *bus)
 		bus->is_added = 1;
 	}
 
-	for (pass = 0; pass < 2; pass++)
-		list_for_each_entry(dev, &bus->devices, bus_list) {
-			if (pci_is_bridge(dev))
-				max = pci_scan_bridge(bus, dev, max, pass);
+	/*
+	 * Calculate how many hotplug bridges and normal bridges there
+	 * are on this bus. We will distribute the additional available
+	 * buses between hotplug bridges.
+	 */
+	for_each_pci_bridge(dev, bus) {
+		if (dev->is_hotplug_bridge)
+			hotplug_bridges++;
+		else
+			normal_bridges++;
+	}
+
+	/*
+	 * Scan bridges that are already configured. We don't touch them
+	 * unless they are misconfigured (which will be done in the second
+	 * scan below).
+	 */
+	for_each_pci_bridge(dev, bus) {
+		cmax = max;
+		max = pci_scan_bridge_extend(bus, dev, max, 0, 0);
+		used_buses += cmax - max;
+	}
+
+	/* Scan bridges that need to be reconfigured */
+	for_each_pci_bridge(dev, bus) {
+		unsigned int buses = 0;
+
+		if (!hotplug_bridges && normal_bridges == 1) {
+			/*
+			 * There is only one bridge on the bus (upstream
+			 * port) so it gets all available buses which it
+			 * can then distribute to the possible hotplug
+			 * bridges below.
+			 */
+			buses = available_buses;
+		} else if (dev->is_hotplug_bridge) {
+			/*
+			 * Distribute the extra buses between hotplug
+			 * bridges if any.
+			 */
+			buses = available_buses / hotplug_bridges;
+			buses = min(buses, available_buses - used_buses);
 		}
 
+		cmax = max;
+		max = pci_scan_bridge_extend(bus, dev, cmax, buses, 1);
+		used_buses += max - cmax;
+	}
+
 	/*
 	 * Make sure a hotplug bridge has at least the minimum requested
-	 * number of buses.
+	 * number of buses but allow it to grow up to the maximum available
+	 * bus number of there is room.
 	 */
-	if (bus->self && bus->self->is_hotplug_bridge && pci_hotplug_bus_size) {
-		if (max - bus->busn_res.start < pci_hotplug_bus_size - 1)
-			max = bus->busn_res.start + pci_hotplug_bus_size - 1;
+	if (bus->self && bus->self->is_hotplug_bridge) {
+		used_buses = max_t(unsigned int, available_buses,
+				   pci_hotplug_bus_size - 1);
+		if (max - start < used_buses) {
+			max = start + used_buses;
+
+			/* Do not allocate more buses than we have room left */
+			if (max > bus->busn_res.end)
+				max = bus->busn_res.end;
+
+			dev_dbg(&bus->dev, "%pR extended by %#02x\n",
+				&bus->busn_res, max - start);
+		}
 	}
 
 	/*
@@ -2445,6 +2557,18 @@ unsigned int pci_scan_child_bus(struct pci_bus *bus)
 	dev_dbg(&bus->dev, "bus scan returning with max=%02x\n", max);
 	return max;
 }
+
+/**
+ * pci_scan_child_bus() - Scan devices below a bus
+ * @bus: Bus to scan for devices
+ *
+ * Scans devices below @bus including subordinate buses. Returns new
+ * subordinate number including all the found devices.
+ */
+unsigned int pci_scan_child_bus(struct pci_bus *bus)
+{
+	return pci_scan_child_bus_extend(bus, 0);
+}
 EXPORT_SYMBOL_GPL(pci_scan_child_bus);
 
 /**
@@ -2737,3 +2861,38 @@ void __init pci_sort_breadthfirst(void)
 {
 	bus_sort_breadthfirst(&pci_bus_type, &pci_sort_bf_cmp);
 }
+
+int pci_hp_add_bridge(struct pci_dev *dev)
+{
+	struct pci_bus *parent = dev->bus;
+	int busnr, start = parent->busn_res.start;
+	unsigned int available_buses = 0;
+	int end = parent->busn_res.end;
+
+	for (busnr = start; busnr <= end; busnr++) {
+		if (!pci_find_bus(pci_domain_nr(parent), busnr))
+			break;
+	}
+	if (busnr-- > end) {
+		dev_err(&dev->dev, "No bus number available for hot-added bridge\n");
+		return -1;
+	}
+
+	/* Scan bridges that are already configured */
+	busnr = pci_scan_bridge(parent, dev, busnr, 0);
+
+	/*
+	 * Distribute the available bus numbers between hotplug-capable
+	 * bridges to make extending the chain later possible.
+	 */
+	available_buses = end - busnr;
+
+	/* Scan bridges that need to be reconfigured */
+	pci_scan_bridge_extend(parent, dev, busnr, available_buses, 1);
+
+	if (!dev->subordinate)
+		return -1;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pci_hp_add_bridge);