Merge: [RHEL10.2] iommu/amd: Allow matching ACPI HID devices without matching UIDs

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1025

# Merge Request Required Information

Upstream-Status: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>

Testing to be done by AMD due to need of specific bios.

## Summary of Changes

```
    iommu/amd: Allow matching ACPI HID devices without matching UIDs

    commit 51c33f3
    Author: Mario Limonciello <mario.limonciello@amd.com>
    Date: Mon May 12 12:30:32 2025 -0500

        iommu/amd: Allow matching ACPI HID devices without matching UIDs

        A BIOS upgrade has changed the IVRS DTE UID for a device that no
        longer matches the UID in the SSDT. In this case there is only
        one ACPI device on the system with that _HID but the _UID mismatch.

        IVRS:
        ```
                      Subtable Type : F0 [Device Entry: ACPI HID Named Device]
                          Device ID : 0060
        Data Setting (decoded below) : 40
                         INITPass : 0
                         EIntPass : 0
                         NMIPass : 0
                         Reserved : 0
                         System MGMT : 0
                         LINT0 Pass : 1
                         LINT1 Pass : 0
                           ACPI HID : "MSFT0201"
                           ACPI CID : 0000000000000000
                         UID Format : 02
                         UID Length : 09
                                UID : "\_SB.MHSP"
        ```

        SSDT:
        ```
        Device (MHSP)
        {
            Name (_ADR, Zero)  // _ADR: Address
            Name (_HID, "MSFT0201")  // _HID: Hardware ID
            Name (_UID, One)  // _UID: Unique ID
        ```

        To handle this case; while enumerating ACPI devices in
        get_acpihid_device_id() count the number of matching ACPI devices with
        a matching _HID. If there is exactly one _HID match then accept it even
        if the UID doesn't match. Other operating systems allow this, but the
        current IVRS spec leaves some ambiguity whether to allow or disallow it.
        This should be clarified in future revisions of the spec. Output
        'Firmware Bug' for this case to encourage it to be solved in the BIOS.

        Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
        Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
        Link: https://lore.kernel.org/r/20250512173129.1274275-1-superm1@kernel.org
        Signed-off-by: Joerg Roedel <jroedel@suse.de>
```

## Approved Development Ticket(s)

JIRA: https://issues.redhat.com/browse/RHEL-89838

Approved-by: Donald Dutile <ddutile@redhat.com>
Approved-by: Phil Auld <pauld@redhat.com>
Approved-by: Aristeu Rozanski <arozansk@redhat.com>
Approved-by: Eder Zulian <ezulian@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: CKI GitLab Kmaint Pipeline Bot <26919896-cki-kmaint-pipeline-bot@users.noreply.gitlab.com>

Author: CKI KWF Bot

drivers/iommu/amd/iommu.c

@@ -241,20 +241,43 @@ static inline int get_acpihid_device_id(struct device *dev,
 					struct acpihid_map_entry **entry)
 {
 	struct acpi_device *adev = ACPI_COMPANION(dev);
-	struct acpihid_map_entry *p;
+	struct acpihid_map_entry *p, *p1 = NULL;
+	int hid_count = 0;
+	bool fw_bug;
 
 	if (!adev)
 		return -ENODEV;
 
 	list_for_each_entry(p, &acpihid_map, list) {
 		if (acpi_dev_hid_uid_match(adev, p->hid,
 					   p->uid[0] ? p->uid : NULL)) {
-			if (entry)
-				*entry = p;
-			return p->devid;
+			p1 = p;
+			fw_bug = false;
+			hid_count = 1;
+			break;
+		}
+
+		/*
+		 * Count HID matches w/o UID, raise FW_BUG but allow exactly one match
+		 */
+		if (acpi_dev_hid_match(adev, p->hid)) {
+			p1 = p;
+			hid_count++;
+			fw_bug = true;
 		}
 	}
-	return -EINVAL;
+
+	if (!p1)
+		return -EINVAL;
+	if (fw_bug)
+		dev_err_once(dev, FW_BUG "No ACPI device matched UID, but %d device%s matched HID.\n",
+			     hid_count, hid_count > 1 ? "s" : "");
+	if (hid_count > 1)
+		return -EINVAL;
+	if (entry)
+		*entry = p1;
+
+	return p1->devid;
 }
 
 static inline int get_device_sbdf_id(struct device *dev)