iommu/vt-d: Fix WARN_ON in iommu probe path

In the Linux kernel, the following vulnerability has been resolved:

iommu/vt-d: Fix WARN_ON in iommu probe path

Commit 1a75cc710b95 ("iommu/vt-d: Use rbtree to track iommu probed

devices") adds all devices probed by the iommu driver in a rbtree

indexed by the source ID of each device. It assumes that each device

has a unique source ID. This assumption is incorrect and the VT-d

spec doesn't state this requirement either.

The reason for using a rbtree to track devices is to look up the device

with PCI bus and devfunc in the paths of handling ATS invalidation time

out error and the PRI I/O page faults. Both are PCI ATS feature related.

Only track the devices that have PCI ATS capabilities in the rbtree to

avoid unnecessary WARN_ON in the iommu probe path. Otherwise, on some

platforms below kernel splat will be displayed and the iommu probe results

in failure.

WARNING: CPU: 3 PID: 166 at drivers/iommu/intel/iommu.c:158 intel_iommu_probe_device+0x319/0xd90

Call Trace:

<TASK>

? __warn+0x7e/0x180

? intel_iommu_probe_device+0x319/0xd90

? report_bug+0x1f8/0x200

? handle_bug+0x3c/0x70

? exc_invalid_op+0x18/0x70

? asm_exc_invalid_op+0x1a/0x20

? intel_iommu_probe_device+0x319/0xd90

? debug_mutex_init+0x37/0x50

__iommu_probe_device+0xf2/0x4f0

iommu_probe_device+0x22/0x70

iommu_bus_notifier+0x1e/0x40

notifier_call_chain+0x46/0x150

blocking_notifier_call_chain+0x42/0x60

bus_notify+0x2f/0x50

device_add+0x5ed/0x7e0

platform_device_add+0xf5/0x240

mfd_add_devices+0x3f9/0x500

? preempt_count_add+0x4c/0xa0

? up_write+0xa2/0x1b0

? __debugfs_create_file+0xe3/0x150

intel_lpss_probe+0x49f/0x5b0

? pci_conf1_write+0xa3/0xf0

intel_lpss_pci_probe+0xcf/0x110 [intel_lpss_pci]

pci_device_probe+0x95/0x120

really_probe+0xd9/0x370

? __pfx___driver_attach+0x10/0x10

__driver_probe_device+0x73/0x150

driver_probe_device+0x19/0xa0

__driver_attach+0xb6/0x180

? __pfx___driver_attach+0x10/0x10

bus_for_each_dev+0x77/0xd0

bus_add_driver+0x114/0x210

driver_register+0x5b/0x110

? __pfx_intel_lpss_pci_driver_init+0x10/0x10 [intel_lpss_pci]

do_one_initcall+0x57/0x2b0

? kmalloc_trace+0x21e/0x280

? do_init_module+0x1e/0x210

do_init_module+0x5f/0x210

load_module+0x1d37/0x1fc0

? init_module_from_file+0x86/0xd0

init_module_from_file+0x86/0xd0

idempotent_init_module+0x17c/0x230

__x64_sys_finit_module+0x56/0xb0

do_syscall_64+0x6e/0x140

entry_SYSCALL_64_after_hwframe+0x71/0x79