[RFC PATCH v2 2/6] powerpc/pseries/iommu: Fix the VFIO_IOMMU_SPAPR_TCE_GET_INFO ioctl output

Shivaprasad G Bhat
2024-04-30T20:06:30Z

The ioctl VFIO_IOMMU_SPAPR_TCE_GET_INFO is not reporting the
actuals on the platform as not all the details are correctly
collected during the platform probe/scan into the iommu_table_group.

Collect the information during the device setup time as the DMA
window property is already looked up on parent nodes anyway.

Signed-off-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
---
arch/powerpc/platforms/pseries/iommu.c | 81 ++++++++++++++++++++++++++------
1 file changed, 67 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index c6850ec1919a..5b68a4918d63 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -857,13 +857,6 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
be32_to_cpu(prop.tce_shift), NULL,
&iommu_table_lpar_multi_ops);

- /* Only for normal boot with default window. Doesn't matter even
- * if we set these with DDW which is 64bit during kdump, since
- * these will not be used during kdump.
- */
- ppci->table_group->tce32_start = be64_to_cpu(prop.dma_base);
- ppci->table_group->tce32_size = 1 << be32_to_cpu(prop.window_shift);
-
if (!iommu_init_table(tbl, ppci->phb->node, 0, 0))
panic("Failed to initialize iommu table");

@@ -1615,6 +1608,71 @@ static bool enable_ddw(struct pci_dev *dev, struct device_node *pdn)
return direct_mapping;
}

+static __u64 query_page_size_to_mask(u32 query_page_size)
+{
+ const long shift[] = {
+ (SZ_4K), (SZ_64K), (SZ_16M),
+ (SZ_32M), (SZ_64M), (SZ_128M),
+ (SZ_256M), (SZ_16G), (SZ_2M)
+ };
+ int i, ret = 0;
+
+ for (i = 0; i < ARRAY_SIZE(shift); i++) {
+ if (query_page_size & (1 << i))
+ ret |= shift[i];
+ }
+
+ return ret;
+}
+
+static void spapr_tce_init_table_group(struct pci_dev *pdev,
+ struct device_node *pdn,
+ struct dynamic_dma_window_prop prop)
+{
+ struct iommu_table_group *table_group = PCI_DN(pdn)->table_group;
+ u32 ddw_avail[DDW_APPLICABLE_SIZE];
+
+ struct ddw_query_response query;
+ int ret;
+
+ /* Only for normal boot with default window. Doesn't matter during
+ * kdump, since these will not be used during kdump.
+ */
+ if (is_kdump_kernel())
+ return;
+
+ if (table_group->max_dynamic_windows_supported != 0)
+ return; /* already initialized */
+
+ table_group->tce32_start = be64_to_cpu(prop.dma_base);
+ table_group->tce32_size = 1 << be32_to_cpu(prop.window_shift);
+
+ if (!of_find_property(pdn, "ibm,dma-window", NULL))
+ dev_err(&pdev->dev, "default dma window missing!\n");
+
+ ret = of_property_read_u32_array(pdn, "ibm,ddw-applicable",
+ &ddw_avail[0], DDW_APPLICABLE_SIZE);
+ if (ret) {
+ table_group->max_dynamic_windows_supported = -1;
+ return;
+ }
+
+ ret = query_ddw(pdev, ddw_avail, &query, pdn);
+ if (ret) {
+ dev_err(&pdev->dev, "%s: query_ddw failed\n", __func__);
+ table_group->max_dynamic_windows_supported = -1;
+ return;
+ }
+
+ if (query.windows_available == 0)
+ table_group->max_dynamic_windows_supported = 1;
+ else
+ table_group->max_dynamic_windows_supported = IOMMU_TABLE_GROUP_MAX_TABLES;
+
+ table_group->max_levels = 1;
+ table_group->pgsizes |= query_page_size_to_mask(query.page_size);
+}
+
static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
{
struct device_node *pdn, *dn;
@@ -1654,13 +1712,6 @@ static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
be32_to_cpu(prop.tce_shift), NULL,
&iommu_table_lpar_multi_ops);

- /* Only for normal boot with default window. Doesn't matter even
- * if we set these with DDW which is 64bit during kdump, since
- * these will not be used during kdump.
- */
- pci->table_group->tce32_start = be64_to_cpu(prop.dma_base);
- pci->table_group->tce32_size = 1 << be32_to_cpu(prop.window_shift);
-
iommu_init_table(tbl, pci->phb->node, 0, 0);
iommu_register_group(pci->table_group,
pci_domain_nr(pci->phb->bus), 0);
@@ -1669,6 +1720,8 @@ static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
pr_debug(" found DMA window, table: %p\n", pci->table_group);
}

+ spapr_tce_init_table_group(dev, pdn, prop);
+
set_iommu_table_base(&dev->dev, pci->table_group->tables[0]);
iommu_add_device(pci->table_group, &dev->dev);
}