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iommu/amd: Fix premature break in init_iommu_one() again

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Commit 283d245468 ("iommu/amd: Fix premature break in
init_iommu_one()") unintentionally broke older platforms - such as
the ASRockRack B550D4-4L - where the BIOS advertises incorrect IOMMU
features.

Move the HATDis check ahead of the GASup check, and re-introduce the
break inside the GASup check to restore correct behavior on affected
platforms.

This is a short-term fix to resolve the regression. Longer term, we
should rework how EFRs are tracked and prioritize the MMIO-advertised
EFR over the one reported via IVRS. That requires more extensive
changes and will be addressed separately.

Fixes: 283d245468 ("iommu/amd: Fix premature break in init_iommu_one()")
Reported-by: Andreas Juch <andreas@juch.cc>
Closes: https://lore.kernel.org/linux-iommu/07b2d390-f7a0-47e2-bc2c-eb0853acf52e@juch.cc/
Tested-by: Andreas Juch <andreas@juch.cc>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
This commit is contained in:
Vasant Hegde 2026-08-24 06:29:07 +00:00 committed by Joerg Roedel
parent 00a7dd6488
commit eb29b7bbc8
1 changed files with 9 additions and 8 deletions
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17
drivers/iommu/amd/init.c
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@ -1922,19 +1922,20 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h,
else
iommu->mmio_phys_end = MMIO_CNTR_CONF_OFFSET;
/* XT and GAM require GA mode. */
if ((h->efr_reg & (0x1 << IOMMU_EFR_GASUP_SHIFT)) == 0) {
amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;
} else {
if (h->efr_reg & BIT(IOMMU_EFR_XTSUP_SHIFT))
amd_iommu_xt_mode = IRQ_REMAP_X2APIC_MODE;
}
if (h->efr_attr & BIT(IOMMU_IVHD_ATTR_HATDIS_SHIFT)) {
pr_warn_once("Host Address Translation is not supported.\n");
amd_iommu_hatdis = true;
}
/* XT and GAM require GA mode. */
if ((h->efr_reg & (0x1 << IOMMU_EFR_GASUP_SHIFT)) == 0) {
amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;
break;
} else {
if (h->efr_reg & BIT(IOMMU_EFR_XTSUP_SHIFT))
amd_iommu_xt_mode = IRQ_REMAP_X2APIC_MODE;
}
early_iommu_features_init(iommu, h);
break;