[PATCH 8/8] iommu/hygon: Add support for Hygon family 18h model 4h IOAPIC
From: Fu Hao
Date: Fri Mar 27 2026 - 04:12:24 EST
The SB IOAPIC is on the device 0xb from Hygon family 18h model 4h.
Signed-off-by: Fu Hao <fuhao@xxxxxxxxxxxxxx>
---
drivers/iommu/amd/init.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index f3fd7f39e..568851cc2 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -3096,6 +3096,9 @@ 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;
@@ -3121,7 +3124,12 @@ 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;
}
--
2.34.1