[PATCH RFC PREVIEW 5/6] iommu/vt-d: drop pasid requirement for prq initialization

From: Klaus Jensen
Date: Mon Aug 26 2024 - 07:41:59 EST


From: Klaus Jensen <k.jensen@xxxxxxxxxxx>

PASID support within the IOMMU is not required to enable the Page
Request Queue, only the PRS capability.

Signed-off-by: Klaus Jensen <k.jensen@xxxxxxxxxxx>
---
drivers/iommu/intel/iommu.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index ada3507d2831..bc1a369c2cf4 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1487,10 +1487,8 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
/* free context mapping */
free_context_table(iommu);

- if (pasid_supported(iommu)) {
- if (ecap_prs(iommu->ecap))
- intel_finish_prq(iommu);
- }
+ if (ecap_prs(iommu->ecap))
+ intel_finish_prq(iommu);
}

/*
@@ -2478,7 +2476,7 @@ static int __init init_dmars(void)

iommu_flush_write_buffer(iommu);

- if (pasid_supported(iommu) && ecap_prs(iommu->ecap)) {
+ if (ecap_prs(iommu->ecap)) {
/*
* Call dmar_alloc_hwirq() with dmar_global_lock held,
* could cause possible lock race condition.
@@ -2919,7 +2917,7 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
intel_iommu_init_qi(iommu);
iommu_flush_write_buffer(iommu);

- if (pasid_supported(iommu) && ecap_prs(iommu->ecap)) {
+ if (ecap_prs(iommu->ecap)) {
ret = intel_enable_prq(iommu);
if (ret)
goto disable_iommu;

--
2.45.2