From: Fu Hao <fuhao@open-hieco.net>
Date: Tue, 7 Apr 2026 08:25:40 +0000 (+0800)
Subject: iommu/amd: Add support for Hygon family 18h model 4h IOAPIC
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5beda8cadb1f072140e58b1edb7604444a42d955;p=thirdparty%2Fkernel%2Flinux.git

iommu/amd: Add support for Hygon family 18h model 4h IOAPIC

The SB IOAPIC is on the device 0xb from Hygon family 18h model 4h.

Signed-off-by: Fu Hao <fuhao@open-hieco.net>
Tested-by: Tingyin Duan <tingyin.duan@gmail.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
---

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index d146fa2f57aed..16073b5614b98 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -3089,6 +3089,9 @@ static void __init free_iommu_resources(void)
 /* SB IOAPIC is always on this device in AMD systems */
 #define IOAPIC_SB_DEVID		((0x00 << 8) | PCI_DEVFN(0x14, 0))
 
+/* SB IOAPIC for Hygon family 18h model 4h is on the device 0xb */
+#define IOAPIC_SB_DEVID_FAM18H_M4H	((0x00 << 8) | PCI_DEVFN(0xb, 0))
+
 static bool __init check_ioapic_information(void)
 {
 	const char *fw_bug = FW_BUG;
@@ -3114,7 +3117,12 @@ static bool __init check_ioapic_information(void)
 			pr_err("%s: IOAPIC[%d] not in IVRS table\n",
 				fw_bug, id);
 			ret = false;
-		} else if (devid == IOAPIC_SB_DEVID) {
+		} else if (devid == IOAPIC_SB_DEVID ||
+			   (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON &&
+			    boot_cpu_data.x86 == 0x18 &&
+			    boot_cpu_data.x86_model >= 0x4 &&
+			    boot_cpu_data.x86_model <= 0xf &&
+			    devid == IOAPIC_SB_DEVID_FAM18H_M4H)) {
 			has_sb_ioapic = true;
 			ret           = true;
 		}