[PATCH v3 3/8] iommu/vt-d: Expose ISA direct mapping region via iommu_get_resv_regions

Lu Baolu
2019-04-29T02:09:20Z

From: James Sewart <jamessewart@arista.com>

To support mapping ISA region via iommu_group_create_direct_mappings,
make sure its exposed by iommu_get_resv_regions. This allows
deduplication of reserved region mappings.

Signed-off-by: James Sewart <jamessewart@arista.com>
---
drivers/iommu/intel-iommu.c | 43 +++++++++++++++++++++++++++++--------
1 file changed, 34 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index af025955f1bc..e9f31b062305 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -339,6 +339,8 @@ static LIST_HEAD(dmar_rmrr_units);
#define for_each_rmrr_units(rmrr) \
list_for_each_entry(rmrr, &dmar_rmrr_units, list)

+static struct iommu_resv_region *isa_resv_region;
+
/* bitmap for indexing intel_iommus */
static int g_num_of_iommus;

@@ -2785,26 +2787,33 @@ static inline int iommu_prepare_rmrr_dev(struct dmar_rmrr_unit *rmrr,
rmrr->end_address);
}

+static inline struct iommu_resv_region *iommu_get_isa_resv_region(void)
+{
+ if (!isa_resv_region)
+ isa_resv_region = iommu_alloc_resv_region(0, 1UL << 24, 0,
+ IOMMU_RESV_DIRECT);
+
+ return isa_resv_region;
+}
+
#ifdef CONFIG_INTEL_IOMMU_FLOPPY_WA
-static inline void iommu_prepare_isa(void)
+static inline void iommu_prepare_isa(struct pci_dev *pdev)
{
- struct pci_dev *pdev;
int ret;
+ struct iommu_resv_region *reg = iommu_get_isa_resv_region();

- pdev = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, NULL);
- if (!pdev)
+ if (!reg)
return;

pr_info("Prepare 0-16MiB unity mapping for LPC\n");
- ret = iommu_prepare_identity_map(&pdev->dev, 0, 16*1024*1024 - 1);
+ ret = iommu_prepare_identity_map(&pdev->dev, reg->start,
+ reg->start + reg->length - 1);

if (ret)
pr_err("Failed to create 0-16MiB identity map - floppy might not work\n");
-
- pci_dev_put(pdev);
}
#else
-static inline void iommu_prepare_isa(void)
+static inline void iommu_prepare_isa(struct pci_dev *pdev)
{
return;
}
@@ -3293,6 +3302,7 @@ static int __init init_dmars(void)
struct dmar_rmrr_unit *rmrr;
bool copied_tables = false;
struct device *dev;
+ struct pci_dev *pdev;
struct intel_iommu *iommu;
int i, ret;

@@ -3473,7 +3483,11 @@ static int __init init_dmars(void)
}
}

- iommu_prepare_isa();
+ pdev = pci_get_class(PCI_CLASS_BRIDGE_ISA << 8, NULL);
+ if (pdev) {
+ iommu_prepare_isa(pdev);
+ pci_dev_put(pdev);
+ }

domains_done:

@@ -5498,6 +5512,17 @@ static void intel_iommu_get_resv_regions(struct device *device,
}
rcu_read_unlock();

+#ifdef CONFIG_INTEL_IOMMU_FLOPPY_WA
+ if (dev_is_pci(device)) {
+ struct pci_dev *pdev = to_pci_dev(device);
+
+ if ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA) {
+ reg = iommu_get_isa_resv_region();
+ list_add_tail(&reg->list, head);
+ }
+ }
+#endif /* CONFIG_INTEL_IOMMU_FLOPPY_WA */
+
reg = iommu_alloc_resv_region(IOAPIC_RANGE_START,
IOAPIC_RANGE_END - IOAPIC_RANGE_START + 1,
0, IOMMU_RESV_MSI);
--
2.17.1