Starting with commit fa212a97f3a3 ("iommu/vt-d: Probe DMA-capable ACPI
name space devices"), we now probe DMA-capable ACPI name
space devices. On Dell XPS 13 9343, which has an Intel LPSS platform
device INTL9C60 enumerated via ACPI, this change leads to the following
warning:

    ------------[ cut here ]------------
    WARNING: CPU: 1 PID: 1 at pci_device_group+0x11a/0x130
    CPU: 1 PID: 1 Comm: swapper/0 Tainted: G                T 5.5.0-rc3+ #22
    Hardware name: Dell Inc. XPS 13 9343/0310JH, BIOS A20 06/06/2019
    RIP: 0010:pci_device_group+0x11a/0x130
    Code: f0 ff ff 48 85 c0 49 89 c4 75 c4 48 8d 74 24 10 48 89 ef e8 48 ef ff ff 48 85 c0 49 89 c4 75 af e8 db f7 ff ff 49 89 c4 eb a5 <0f> 0b 49 c7 c4 ea ff ff ff eb 9a e8 96 1e c7 ff 66 0f 1f 44 00 00
    RSP: 0000:ffffc0d6c0043cb0 EFLAGS: 00010202
    RAX: 0000000000000000 RBX: ffffa3d1d43dd810 RCX: 0000000000000000
    RDX: ffffa3d1d4fecf80 RSI: ffffa3d12943dcc0 RDI: ffffa3d1d43dd810
    RBP: ffffa3d1d43dd810 R08: 0000000000000000 R09: ffffa3d1d4c04a80
    R10: ffffa3d1d4c00880 R11: ffffa3d1d44ba000 R12: 0000000000000000
    R13: ffffa3d1d4383b80 R14: ffffa3d1d4c090d0 R15: ffffa3d1d4324530
    FS:  0000000000000000(0000) GS:ffffa3d1d6700000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 000000000460a001 CR4: 00000000003606e0
    Call Trace:
     ? iommu_group_get_for_dev+0x81/0x1f0
     ? intel_iommu_add_device+0x61/0x170
     ? iommu_probe_device+0x43/0xd0
     ? intel_iommu_init+0x1fa2/0x2235
     ? pci_iommu_init+0x52/0xe7
     ? e820__memblock_setup+0x15c/0x15c
     ? do_one_initcall+0xcc/0x27e
     ? kernel_init_freeable+0x169/0x259
     ? rest_init+0x95/0x95
     ? kernel_init+0x5/0xeb
     ? ret_from_fork+0x35/0x40
    ---[ end trace 28473e7abc25b92c ]---
    DMAR: ACPI name space devices didn't probe correctly

The bug results from the fact that while we now enumerate ACPI devices,
we aren't able to handle any non-PCI device when generating the device
group. Fix the issue by implementing an Intel-specific callback that
returns `pci_device_group` only if the device is a PCI device.
Otherwise, it will return a generic device group.

Fixes: fa212a97f3a3 ("iommu/vt-d: Probe DMA-capable ACPI name space devices")
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Cc: stable@vger.kernel.org # v5.3+
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>