[PATCH kernel v7 15/20] powerpc/powernv/npu: Add release_ownership hook

Alexey Kardashevskiy
2018-12-20T08:23:45Z

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 <aik@ozlabs.ru>
---
Changes:
v5:
* removed opal_purge_cache as it is a part of reset in skiboot now
---
arch/powerpc/platforms/powernv/npu-dma.c | 51 ++++++++++++++++++++++++
1 file changed, 51 insertions(+)

diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
index d93a2cd..e06043b 100644
--- a/arch/powerpc/platforms/powernv/npu-dma.c
+++ b/arch/powerpc/platforms/powernv/npu-dma.c
@@ -300,6 +300,7 @@ 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
@@ -321,12 +322,28 @@ 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 */

@@ -1237,3 +1254,37 @@ void pnv_npu2_map_lpar(struct pnv_ioda_pe *gpe, unsigned long msr)
list_for_each_entry(gpdev, &gpe->pbus->devices, bus_list)
pnv_npu2_map_lpar_dev(gpdev, 0, msr);
}
+
+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;
+ struct pnv_phb *nphb;
+
+ if (!npdev)
+ return -ENODEV;
+
+ hose = pci_bus_to_host(npdev->bus);
+ 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);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pnv_npu2_unmap_lpar_dev);
--
2.17.1