[PATCH kernel v3 19/22] powerpc/powernv/npu: Add release_ownership hook

[Alexey Kardashevskiy]

In order to make ATS work and translate addresses for arbitrary
LPID and PID, we need to program an NPU with LPID and allow PID wildcard
matching with a specific MSR mask.

This implements a helper to assign a GPU to LPAR and program the NPU
with a wildcard for PID and a helper to do clean-up. The helper takes
MSR (only DR/HV/PR/SF bits are allowed) to program them into NPU2 for
ATS checkout requests support.

This exports pnv_npu2_unmap_lpar_dev() as following patches will use it
from the VFIO driver.

Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
 arch/powerpc/platforms/powernv/npu-dma.c | 47 ++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/npu-dma.c 
b/arch/powerpc/platforms/powernv/npu-dma.c
index 2231f4c..48adaa5 100644
--- a/arch/powerpc/platforms/powernv/npu-dma.c
+++ b/arch/powerpc/platforms/powernv/npu-dma.c
@@ -289,6 +289,7 @@ static void pnv_npu_take_ownership(struct iommu_table_group 
*table_group)
                        table_group);
        struct pnv_phb *phb = npe->phb;
        int64_t rc;
+       struct pci_dev *gpdev = NULL;
 
        /*
         * Note: NPU has just a single TVE in the hardware which means that
@@ -310,12 +311,28 @@ static void pnv_npu_take_ownership(struct 
iommu_table_group *table_group)
                return;
        }
        pnv_pci_ioda2_tce_invalidate_entire(npe->phb, false);
+
+       get_gpu_pci_dev_and_pe(npe, &gpdev);
+       if (gpdev)
+               pnv_npu2_unmap_lpar_dev(gpdev);
+}
+
+static void pnv_npu_release_ownership(struct iommu_table_group *table_group)
+{
+       struct pnv_ioda_pe *npe = container_of(table_group, struct pnv_ioda_pe,
+                       table_group);
+       struct pci_dev *gpdev = NULL;
+
+       get_gpu_pci_dev_and_pe(npe, &gpdev);
+       if (gpdev)
+               pnv_npu2_map_lpar_dev(gpdev, 0, MSR_DR | MSR_PR | MSR_HV);
 }
 
 static struct iommu_table_group_ops pnv_pci_npu_ops = {
        .set_window = pnv_npu_set_window,
        .unset_window = pnv_npu_unset_window,
        .take_ownership = pnv_npu_take_ownership,
+       .release_ownership = pnv_npu_release_ownership,
 };
 #endif /* !CONFIG_IOMMU_API */
 
@@ -1239,3 +1256,33 @@ void pnv_npu2_map_lpar(struct pnv_ioda_pe *gpe, unsigned 
long msr)
                                        ret);
        }
 }
+
+int pnv_npu2_unmap_lpar_dev(struct pci_dev *gpdev)
+{
+       int ret;
+       struct pci_dev *npdev = pnv_pci_get_npu_dev(gpdev, 0);
+       struct pci_controller *hose = pci_bus_to_host(npdev->bus);
+       struct pnv_phb *nphb = hose->private_data;
+
+       dev_dbg(&gpdev->dev, "destroy context opalid=%llu\n",
+                       nphb->opal_id);
+       ret = opal_npu_destroy_context(nphb->opal_id, 0/*__unused*/,
+                       PCI_DEVID(gpdev->bus->number, gpdev->devfn));
+       if (ret < 0) {
+               dev_err(&gpdev->dev, "Failed to destroy context: %d\n", ret);
+               return ret;
+       }
+
+       /* Set LPID to 0 anyway, just to be safe */
+       dev_dbg(&gpdev->dev, "Map LPAR opalid=%llu lparid=0\n", nphb->opal_id);
+       ret = opal_npu_map_lpar(nphb->opal_id,
+                       PCI_DEVID(gpdev->bus->number, gpdev->devfn), 0 /*LPID*/,
+                       0 /* LPCR bits */);
+       if (ret)
+               dev_err(&gpdev->dev, "Error %d mapping device to LPAR\n", ret);
+
+       opal_purge_cache();
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(pnv_npu2_unmap_lpar_dev);
-- 
2.17.1