Thread (35 messages) 35 messages, 4 authors, 2018-12-13
STALE2723d

[PATCH kernel v4 16/19] powerpc/powernv/npu: Add release_ownership hook

From: Alexey Kardashevskiy <hidden>
Date: 2018-11-23 06:20:46
Subsystem: linux for powerpc (32-bit and 64-bit), the rest · Maintainers: Madhavan Srinivasan, Michael Ellerman, Linus Torvalds

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 <redacted>
---
 arch/powerpc/platforms/powernv/npu-dma.c | 53 ++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
index 09edda6..41cc3c4 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 */
 
@@ -1231,3 +1248,39 @@ 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);
+
+	opal_purge_cache();
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pnv_npu2_unmap_lpar_dev);
-- 
2.17.1
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