Log bridge secondary/subordinate bus and window information at the same
time we log the bridge BARs, just after discovering the bridge and before
scanning the bridge's secondary bus.  This logs the bridge and downstream
devices in a more logical order:

  - pci 0000:00:01.0: [8086:1901] type 01 class 0x060400
  - pci 0000:01:00.0: [10de:13b6] type 00 class 0x030200
  - pci 0000:01:00.0: reg 0x10: [mem 0xec000000-0xecffffff]
  - pci 0000:00:01.0: PCI bridge to [bus 01]
  - pci 0000:00:01.0:   bridge window [io  0xe000-0xefff]

  + pci 0000:00:01.0: [8086:1901] type 01 class 0x060400
  + pci 0000:00:01.0: PCI bridge to [bus 01]
  + pci 0000:00:01.0:   bridge window [io  0xe000-0xefff]
  + pci 0000:01:00.0: [10de:13b6] type 00 class 0x030200
  + pci 0000:01:00.0: reg 0x10: [mem 0xec000000-0xecffffff]

Note that we read the windows into a temporary struct resource that is
thrown away, not into the resources in the struct pci_bus.

The windows may be adjusted after we know what downstream devices require,
and those adjustments are logged as they are made.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Previously pci_read_bridge_io(), pci_read_bridge_mmio(), and
pci_read_bridge_mmio_pref() unconditionally logged the bridge window
resource.  A future change will call these functions earlier and more
often.  Add a "log" parameter so callers can control whether to generate
the log message.  No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Previously we logged information about devices *below* the bridge before
logging information about the bridge itself, e.g.,

  pci 0000:00:01.0: [8086:1901] type 01 class 0x060400
  pci 0000:01:00.0: [10de:13b6] type 00 class 0x030200
  pci 0000:01:00.0: reg 0x10: [mem 0xec000000-0xecffffff]
  pci 0000:00:01.0: PCI bridge to [bus 01]
  pci 0000:00:01.0:   bridge window [io  0xe000-0xefff]

This is partly because the bridge windows are read in this path:

  pci_scan_child_bus_extend
    for (devfn = 0; devfn < 256; devfn += 8)
      pci_scan_slot(bus, devfn)       # scan below bridge
    pcibios_fixup_bus(bus)
      pci_read_bridge_bases(bus)      # read bridge windows
        pci_read_bridge_io(bus)

Remove the assumption that the secondary (child) pci_bus already exists by
passing in the bridge device (instead of the pci_bus) and a resource
pointer when reading bridge windows.  A future change can use this to log
the bridge details before we enumerate the devices below the bridge.

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Move pci_read_bridge_windows() below the functions that read the I/O,
memory, and prefetchable memory windows, so pci_read_bridge_windows() can
use them in the future.  No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Use the pci_resource_name() to get the name of the resource and use it
while printing log messages.

[bhelgaas: rename to match struct resource * names, also use names in other
BAR messages]
Link: https://lore.kernel.org/r/20211106112606.192563-3-puranjay12@gmail.com
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Log the device type when enumeration a device.  Sample output changes:

  - pci 0000:00:00.0: [8086:1237] type 00 class 0x060000
  + pci 0000:00:00.0: [8086:1237] type 00 class 0x060000 conventional PCI endpoint

  - pci 0000:00:1c.0: [8086:a110] type 01 class 0x060400
  + pci 0000:00:1c.0: [8086:a110] type 01 class 0x060400 PCIe Root Port

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

- Use FIELD_GET()/FIELD_PREP() when possible throughout drivers/pci/ (Ilpo
  Järvinen, Bjorn Helgaas)

- Rework DPC control programming for clarity (Ilpo Järvinen)

* pci/field-get:
  PCI/portdrv: Use FIELD_GET()
  PCI/VC: Use FIELD_GET()
  PCI/PTM: Use FIELD_GET()
  PCI/PME: Use FIELD_GET()
  PCI/ATS: Use FIELD_GET()
  PCI/ATS: Show PASID Capability register width in bitmasks
  PCI: Use FIELD_GET() in Sapphire RX 5600 XT Pulse quirk
  PCI: Use FIELD_GET()
  PCI/MSI: Use FIELD_GET/PREP()
  PCI/DPC: Use defines with DPC reason fields
  PCI/DPC: Use defined fields with DPC_CTL register
  PCI/DPC: Use FIELD_GET()
  PCI: hotplug: Use FIELD_GET/PREP()
  PCI: dwc: Use FIELD_GET/PREP()
  PCI: cadence: Use FIELD_GET()
  PCI: Use FIELD_GET() to extract Link Width
  PCI: mvebu: Use FIELD_PREP() with Link Width
  PCI: tegra194: Use FIELD_GET()/FIELD_PREP() with Link Width fields

# Conflicts:
#	drivers/pci/controller/dwc/pcie-tegra194.c

Use FIELD_GET() and FIELD_PREP() to remove dependences on the field
position, i.e., the shift value.  No functional change intended.

Link: https://lore.kernel.org/r/20231010204436.1000644-2-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

Placing PCI error code check inside "if" condition usually results in need
to split lines. Combined with additional conditions the "if" condition
becomes messy.

Convert to the usual error handling pattern with an additional variable to
improve code readability. In addition, reverse the logic in
pci_find_vsec_capability() to get rid of &&.

No functional changes intended.

Link: https://lore.kernel.org/r/20230911125354.25501-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: PCI_POSSIBLE_ERROR()]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

release_resource() doesn't actually free the resource or resource list
entry so free the resource list entry to avoid a leak.

Closes: https://lore.kernel.org/r/878r9sga1t.fsf@kernel.org/
Fixes: e54223275ba1 ("PCI: Release resource invalidated by coalescing")
Link: https://lore.kernel.org/r/20230906110846.225369-1-ross.lagerwall@citrix.com
Reported-by: Kalle Valo <kvalo@kernel.org>
Tested-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: stable@vger.kernel.org      # v5.16+