[PATCH 2/3] iommu/amd: Add amd_iommu_device_info() function

From: Joerg Roedel
Date: Thu Dec 15 2011 - 05:23:35 EST


This function can be used to find out which features
necessary for IOMMUv2 usage are available on a given device.

Signed-off-by: Joerg Roedel <joerg.roedel@xxxxxxx>
---
drivers/iommu/amd_iommu.c | 43 +++++++++++++++++++++++++++++++++++++++++++
include/linux/amd-iommu.h | 26 ++++++++++++++++++++++++++
2 files changed, 69 insertions(+), 0 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index d5074f4..03944e7 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3565,3 +3565,46 @@ void amd_iommu_enable_device_erratum(struct pci_dev *pdev, u32 erratum)
dev_data->errata |= (1 << erratum);
}
EXPORT_SYMBOL(amd_iommu_enable_device_erratum);
+
+int amd_iommu_device_info(struct pci_dev *pdev,
+ struct amd_iommu_device_info *info)
+{
+ int max_pasids;
+ int pos;
+
+ if (pdev == NULL || info == NULL)
+ return -EINVAL;
+
+ if (!amd_iommu_v2_supported())
+ return -EINVAL;
+
+ memset(info, 0, sizeof(*info));
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS);
+ if (pos)
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_ATS_SUP;
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
+ if (pos)
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_PRI_SUP;
+
+ pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PASID);
+ if (pos) {
+ int features;
+
+ max_pasids = 1 << (9 * (amd_iommu_max_glx_val + 1));
+ max_pasids = min(max_pasids, (1 << 20));
+
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_PASID_SUP;
+ info->max_pasids = min(pci_max_pasids(pdev), max_pasids);
+
+ features = pci_pasid_features(pdev);
+ if (features & PCI_PASID_CAP_EXEC)
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_EXEC_SUP;
+ if (features & PCI_PASID_CAP_PRIV)
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_PRIV_SUP;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(amd_iommu_device_info);
diff --git a/include/linux/amd-iommu.h b/include/linux/amd-iommu.h
index 06688c4..c03c281 100644
--- a/include/linux/amd-iommu.h
+++ b/include/linux/amd-iommu.h
@@ -119,6 +119,32 @@ typedef int (*amd_iommu_invalid_ppr_cb)(struct pci_dev *pdev,
extern int amd_iommu_set_invalid_ppr_cb(struct pci_dev *pdev,
amd_iommu_invalid_ppr_cb cb);

+/**
+ * amd_iommu_device_info() - Get information about IOMMUv2 support of a
+ * PCI device
+ * @pdev: PCI device to query information from
+ * @info: A pointer to an amd_iommu_device_info structure which will contain
+ * the information about the PCI device
+ *
+ * Returns 0 on success, negative value on error
+ */
+
+#define AMD_IOMMU_DEVICE_FLAG_ATS_SUP 0x1 /* ATS feature supported */
+#define AMD_IOMMU_DEVICE_FLAG_PRI_SUP 0x2 /* PRI feature supported */
+#define AMD_IOMMU_DEVICE_FLAG_PASID_SUP 0x4 /* PASID context supported */
+#define AMD_IOMMU_DEVICE_FLAG_EXEC_SUP 0x8 /* Device may request execution
+ on memory pages */
+#define AMD_IOMMU_DEVICE_FLAG_PRIV_SUP 0x10 /* Device may request
+ super-user privileges */
+
+struct amd_iommu_device_info {
+ int max_pasids;
+ u32 flags;
+};
+
+extern int amd_iommu_device_info(struct pci_dev *pdev,
+ struct amd_iommu_device_info *info);
+
#else

static inline int amd_iommu_detect(void) { return -ENODEV; }
--
1.7.5.4


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