Merge tag 'pci-v5.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci

Pull PCI updates from Bjorn Helgaas:
 "Enumeration:

   - Consolidate _HPP/_HPX stuff in pci-acpi.c and simplify it
     (Krzysztof Wilczynski)

   - Fix incorrect PCIe device types and remove dev->has_secondary_link
     to simplify code that deals with upstream/downstream ports (Mika
     Westerberg)

   - After suspend, restore Resizable BAR size bits correctly for 1MB
     BARs (Sumit Saxena)

   - Enable PCI_MSI_IRQ_DOMAIN support for RISC-V (Wesley Terpstra)

  Virtualization:

   - Add ACS quirks for iProc PAXB (Abhinav Ratna), Amazon Annapurna
     Labs (Ali Saidi)

   - Move sysfs SR-IOV functions to iov.c (Kelsey Skunberg)

   - Remove group write permissions from sysfs sriov_numvfs,
     sriov_drivers_autoprobe (Kelsey Skunberg)

  Hotplug:

   - Simplify pciehp indicator control (Denis Efremov)

  Peer-to-peer DMA:

   - Allow P2P DMA between root ports for whitelisted bridges (Logan
     Gunthorpe)

   - Whitelist some Intel host bridges for P2P DMA (Logan Gunthorpe)

   - DMA map P2P DMA requests that traverse host bridge (Logan
     Gunthorpe)

  Amazon Annapurna Labs host bridge driver:

   - Add DT binding and controller driver (Jonathan Chocron)

  Hyper-V host bridge driver:

   - Fix hv_pci_dev->pci_slot use-after-free (Dexuan Cui)

   - Fix PCI domain number collisions (Haiyang Zhang)

   - Use instance ID bytes 4 & 5 as PCI domain numbers (Haiyang Zhang)

   - Fix build errors on non-SYSFS config (Randy Dunlap)

  i.MX6 host bridge driver:

   - Limit DBI register length (Stefan Agner)

  Intel VMD host bridge driver:

   - Fix config addressing issues (Jon Derrick)

  Layerscape host bridge driver:

   - Add bar_fixed_64bit property to endpoint driver (Xiaowei Bao)

   - Add CONFIG_PCI_LAYERSCAPE_EP to build EP/RC drivers separately
     (Xiaowei Bao)

  Mediatek host bridge driver:

   - Add MT7629 controller support (Jianjun Wang)

  Mobiveil host bridge driver:

   - Fix CPU base address setup (Hou Zhiqiang)

   - Make "num-lanes" property optional (Hou Zhiqiang)

  Tegra host bridge driver:

   - Fix OF node reference leak (Nishka Dasgupta)

   - Disable MSI for root ports to work around design problem (Vidya
     Sagar)

   - Add Tegra194 DT binding and controller support (Vidya Sagar)

   - Add support for sideband pins and slot regulators (Vidya Sagar)

   - Add PIPE2UPHY support (Vidya Sagar)

  Misc:

   - Remove unused pci_block_cfg_access() et al (Kelsey Skunberg)

   - Unexport pci_bus_get(), etc (Kelsey Skunberg)

   - Hide PM, VC, link speed, ATS, ECRC, PTM constants and interfaces in
     the PCI core (Kelsey Skunberg)

   - Clean up sysfs DEVICE_ATTR() usage (Kelsey Skunberg)

   - Mark expected switch fall-through (Gustavo A. R. Silva)

   - Propagate errors for optional regulators and PHYs (Thierry Reding)

   - Fix kernel command line resource_alignment parameter issues (Logan
     Gunthorpe)"

* tag 'pci-v5.4-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (112 commits)
  PCI: Add pci_irq_vector() and other stubs when !CONFIG_PCI
  arm64: tegra: Add PCIe slot supply information in p2972-0000 platform
  arm64: tegra: Add configuration for PCIe C5 sideband signals
  PCI: tegra: Add support to enable slot regulators
  PCI: tegra: Add support to configure sideband pins
  PCI: vmd: Fix shadow offsets to reflect spec changes
  PCI: vmd: Fix config addressing when using bus offsets
  PCI: dwc: Add validation that PCIe core is set to correct mode
  PCI: dwc: al: Add Amazon Annapurna Labs PCIe controller driver
  dt-bindings: PCI: Add Amazon's Annapurna Labs PCIe host bridge binding
  PCI: Add quirk to disable MSI-X support for Amazon's Annapurna Labs Root Port
  PCI/VPD: Prevent VPD access for Amazon's Annapurna Labs Root Port
  PCI: Add ACS quirk for Amazon Annapurna Labs root ports
  PCI: Add Amazon's Annapurna Labs vendor ID
  MAINTAINERS: Add PCI native host/endpoint controllers designated reviewer
  PCI: hv: Use bytes 4 and 5 from instance ID as the PCI domain numbers
  dt-bindings: PCI: tegra: Add PCIe slot supplies regulator entries
  dt-bindings: PCI: tegra: Add sideband pins configuration entries
  PCI: tegra: Add Tegra194 PCIe support
  PCI: Get rid of dev->has_secondary_link flag
  ...

1 files changed, 80 insertions, 14 deletions

diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
index 0ca73c851e0f..f1f300218fab 100644
--- a/drivers/pci/controller/pci-hyperv.c
+++ b/drivers/pci/controller/pci-hyperv.c
@@ -2809,6 +2809,48 @@ static void put_hvpcibus(struct hv_pcibus_device *hbus)
 		complete(&hbus->remove_event);
 }
 
+#define HVPCI_DOM_MAP_SIZE (64 * 1024)
+static DECLARE_BITMAP(hvpci_dom_map, HVPCI_DOM_MAP_SIZE);
+
+/*
+ * PCI domain number 0 is used by emulated devices on Gen1 VMs, so define 0
+ * as invalid for passthrough PCI devices of this driver.
+ */
+#define HVPCI_DOM_INVALID 0
+
+/**
+ * hv_get_dom_num() - Get a valid PCI domain number
+ * Check if the PCI domain number is in use, and return another number if
+ * it is in use.
+ *
+ * @dom: Requested domain number
+ *
+ * return: domain number on success, HVPCI_DOM_INVALID on failure
+ */
+static u16 hv_get_dom_num(u16 dom)
+{
+	unsigned int i;
+
+	if (test_and_set_bit(dom, hvpci_dom_map) == 0)
+		return dom;
+
+	for_each_clear_bit(i, hvpci_dom_map, HVPCI_DOM_MAP_SIZE) {
+		if (test_and_set_bit(i, hvpci_dom_map) == 0)
+			return i;
+	}
+
+	return HVPCI_DOM_INVALID;
+}
+
+/**
+ * hv_put_dom_num() - Mark the PCI domain number as free
+ * @dom: Domain number to be freed
+ */
+static void hv_put_dom_num(u16 dom)
+{
+	clear_bit(dom, hvpci_dom_map);
+}
+
 /**
  * hv_pci_probe() - New VMBus channel probe, for a root PCI bus
  * @hdev:	VMBus's tracking struct for this root PCI bus
@@ -2820,6 +2862,7 @@ static int hv_pci_probe(struct hv_device *hdev,
 			const struct hv_vmbus_device_id *dev_id)
 {
 	struct hv_pcibus_device *hbus;
+	u16 dom_req, dom;
 	char *name;
 	int ret;
 
@@ -2835,19 +2878,34 @@ static int hv_pci_probe(struct hv_device *hdev,
 	hbus->state = hv_pcibus_init;
 
 	/*
-	 * The PCI bus "domain" is what is called "segment" in ACPI and
-	 * other specs.  Pull it from the instance ID, to get something
-	 * unique.  Bytes 8 and 9 are what is used in Windows guests, so
-	 * do the same thing for consistency.  Note that, since this code
-	 * only runs in a Hyper-V VM, Hyper-V can (and does) guarantee
-	 * that (1) the only domain in use for something that looks like
-	 * a physical PCI bus (which is actually emulated by the
-	 * hypervisor) is domain 0 and (2) there will be no overlap
-	 * between domains derived from these instance IDs in the same
-	 * VM.
+	 * The PCI bus "domain" is what is called "segment" in ACPI and other
+	 * specs. Pull it from the instance ID, to get something usually
+	 * unique. In rare cases of collision, we will find out another number
+	 * not in use.
+	 *
+	 * Note that, since this code only runs in a Hyper-V VM, Hyper-V
+	 * together with this guest driver can guarantee that (1) The only
+	 * domain used by Gen1 VMs for something that looks like a physical
+	 * PCI bus (which is actually emulated by the hypervisor) is domain 0.
+	 * (2) There will be no overlap between domains (after fixing possible
+	 * collisions) in the same VM.
 	 */
-	hbus->sysdata.domain = hdev->dev_instance.b[9] |
-			       hdev->dev_instance.b[8] << 8;
+	dom_req = hdev->dev_instance.b[5] << 8 | hdev->dev_instance.b[4];
+	dom = hv_get_dom_num(dom_req);
+
+	if (dom == HVPCI_DOM_INVALID) {
+		dev_err(&hdev->device,
+			"Unable to use dom# 0x%hx or other numbers", dom_req);
+		ret = -EINVAL;
+		goto free_bus;
+	}
+
+	if (dom != dom_req)
+		dev_info(&hdev->device,
+			 "PCI dom# 0x%hx has collision, using 0x%hx",
+			 dom_req, dom);
+
+	hbus->sysdata.domain = dom;
 
 	hbus->hdev = hdev;
 	refcount_set(&hbus->remove_lock, 1);
@@ -2862,7 +2920,7 @@ static int hv_pci_probe(struct hv_device *hdev,
 					   hbus->sysdata.domain);
 	if (!hbus->wq) {
 		ret = -ENOMEM;
-		goto free_bus;
+		goto free_dom;
 	}
 
 	ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
@@ -2946,6 +3004,8 @@ close:
 	vmbus_close(hdev->channel);
 destroy_wq:
 	destroy_workqueue(hbus->wq);
+free_dom:
+	hv_put_dom_num(hbus->sysdata.domain);
 free_bus:
 	free_page((unsigned long)hbus);
 	return ret;
@@ -3008,8 +3068,8 @@ static int hv_pci_remove(struct hv_device *hdev)
 		/* Remove the bus from PCI's point of view. */
 		pci_lock_rescan_remove();
 		pci_stop_root_bus(hbus->pci_bus);
-		pci_remove_root_bus(hbus->pci_bus);
 		hv_pci_remove_slots(hbus);
+		pci_remove_root_bus(hbus->pci_bus);
 		pci_unlock_rescan_remove();
 		hbus->state = hv_pcibus_removed;
 	}
@@ -3027,6 +3087,9 @@ static int hv_pci_remove(struct hv_device *hdev)
 	put_hvpcibus(hbus);
 	wait_for_completion(&hbus->remove_event);
 	destroy_workqueue(hbus->wq);
+
+	hv_put_dom_num(hbus->sysdata.domain);
+
 	free_page((unsigned long)hbus);
 	return 0;
 }
@@ -3058,6 +3121,9 @@ static void __exit exit_hv_pci_drv(void)
 
 static int __init init_hv_pci_drv(void)
 {
+	/* Set the invalid domain number's bit, so it will not be used */
+	set_bit(HVPCI_DOM_INVALID, hvpci_dom_map);
+
 	/* Initialize PCI block r/w interface */
 	hvpci_block_ops.read_block = hv_read_config_block;
 	hvpci_block_ops.write_block = hv_write_config_block;