powerpc/powernv/npu: TCE Kill helpers cleanup

NPU PHB TCE Kill register is exactly the same as in the rest of POWER8
so let's reuse the existing code for NPU. The only bit missing is
a helper to reset the entire TCE cache so this moves such a helper
from NPU code and renames it.

Since pnv_npu_tce_invalidate() does really invalidate the entire cache,
this uses pnv_pci_ioda2_tce_invalidate_entire() directly for NPU.
This adds an explicit comment for workaround for invalidating NPU TCE
cache.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/npu-dma.c

@@ -25,8 +25,6 @@
  * Other types of TCE cache invalidation are not functional in the
  * hardware.
  */
-#define TCE_KILL_INVAL_ALL PPC_BIT(0)
-
 static struct pci_dev *get_pci_dev(struct device_node *dn)
 {
 	return PCI_DN(dn)->pcidev;
@@ -161,45 +159,6 @@ static struct pnv_ioda_pe *get_gpu_pci_dev_and_pe(struct pnv_ioda_pe *npe,
 	return pe;
 }
 
-void pnv_npu_tce_invalidate_entire(struct pnv_ioda_pe *npe)
-{
-	struct pnv_phb *phb = npe->phb;
-
-	if (WARN_ON(phb->type != PNV_PHB_NPU ||
-		    !phb->ioda.tce_inval_reg ||
-		    !(npe->flags & PNV_IODA_PE_DEV)))
-		return;
-
-	mb(); /* Ensure previous TCE table stores are visible */
-	__raw_writeq(cpu_to_be64(TCE_KILL_INVAL_ALL),
-		phb->ioda.tce_inval_reg);
-}
-
-void pnv_npu_tce_invalidate(struct pnv_ioda_pe *npe,
-				struct iommu_table *tbl,
-				unsigned long index,
-				unsigned long npages,
-				bool rm)
-{
-	struct pnv_phb *phb = npe->phb;
-
-	/* We can only invalidate the whole cache on NPU */
-	unsigned long val = TCE_KILL_INVAL_ALL;
-
-	if (WARN_ON(phb->type != PNV_PHB_NPU ||
-		    !phb->ioda.tce_inval_reg ||
-		    !(npe->flags & PNV_IODA_PE_DEV)))
-		return;
-
-	mb(); /* Ensure previous TCE table stores are visible */
-	if (rm)
-		__raw_rm_writeq(cpu_to_be64(val),
-		  (__be64 __iomem *) phb->ioda.tce_inval_reg_phys);
-	else
-		__raw_writeq(cpu_to_be64(val),
-			phb->ioda.tce_inval_reg);
-}
-
 void pnv_npu_init_dma_pe(struct pnv_ioda_pe *npe)
 {
 	struct pnv_ioda_pe *gpe;

arch/powerpc/platforms/powernv/pci-ioda.c

@@ -1840,9 +1840,23 @@ static struct iommu_table_ops pnv_ioda1_iommu_ops = {
 	.get = pnv_tce_get,
 };
 
+#define TCE_KILL_INVAL_ALL  PPC_BIT(0)
 #define TCE_KILL_INVAL_PE   PPC_BIT(1)
 #define TCE_KILL_INVAL_TCE  PPC_BIT(2)
 
+void pnv_pci_ioda2_tce_invalidate_entire(struct pnv_phb *phb, bool rm)
+{
+	const unsigned long val = TCE_KILL_INVAL_ALL;
+
+	mb(); /* Ensure previous TCE table stores are visible */
+	if (rm)
+		__raw_rm_writeq(cpu_to_be64(val),
+				(__be64 __iomem *)
+				phb->ioda.tce_inval_reg_phys);
+	else
+		__raw_writeq(cpu_to_be64(val), phb->ioda.tce_inval_reg);
+}
+
 static inline void pnv_pci_ioda2_tce_invalidate_pe(struct pnv_ioda_pe *pe)
 {
 	/* 01xb - invalidate TCEs that match the specified PE# */
@@ -1863,7 +1877,7 @@ static inline void pnv_pci_ioda2_tce_invalidate_pe(struct pnv_ioda_pe *pe)
 			if (!npe || npe->phb->type != PNV_PHB_NPU)
 				continue;
 
-			pnv_npu_tce_invalidate_entire(npe);
+			pnv_pci_ioda2_tce_invalidate_entire(npe->phb, false);
 		}
 }
 
@@ -1912,14 +1926,19 @@ static void pnv_pci_ioda2_tce_invalidate(struct iommu_table *tbl,
 			index, npages);
 
 		if (pe->flags & PNV_IODA_PE_PEER)
-			/* Invalidate PEs using the same TCE table */
+			/*
+			 * The NVLink hardware does not support TCE kill
+			 * per TCE entry so we have to invalidate
+			 * the entire cache for it.
+			 */
 			for (i = 0; i < PNV_IODA_MAX_PEER_PES; i++) {
 				npe = pe->peers[i];
-				if (!npe || npe->phb->type != PNV_PHB_NPU)
+				if (!npe || npe->phb->type != PNV_PHB_NPU ||
+						!npe->phb->ioda.tce_inval_reg)
 					continue;
 
-				pnv_npu_tce_invalidate(npe, tbl, index,
-							npages, rm);
+				pnv_pci_ioda2_tce_invalidate_entire(npe->phb,
+						rm);
 			}
 	}
 }

arch/powerpc/platforms/powernv/pci.h

@@ -218,15 +218,10 @@ extern int pnv_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type);
 extern void pnv_teardown_msi_irqs(struct pci_dev *pdev);
 
 /* Nvlink functions */
-extern void pnv_npu_tce_invalidate_entire(struct pnv_ioda_pe *npe);
-extern void pnv_npu_tce_invalidate(struct pnv_ioda_pe *npe,
-				       struct iommu_table *tbl,
-				       unsigned long index,
-				       unsigned long npages,
-				       bool rm);
 extern void pnv_npu_init_dma_pe(struct pnv_ioda_pe *npe);
 extern void pnv_npu_setup_dma_pe(struct pnv_ioda_pe *npe);
 extern int pnv_npu_dma_set_bypass(struct pnv_ioda_pe *npe, bool enabled);
 extern int pnv_npu_dma_set_mask(struct pci_dev *npdev, u64 dma_mask);
+extern void pnv_pci_ioda2_tce_invalidate_entire(struct pnv_phb *phb, bool rm);
 
 #endif /* __POWERNV_PCI_H */