powerpc/powernv: Remove DMA32 PE list

PEs are put into PHB DMA32 list (phb->ioda.pe_dma_list) according
to their DMA32 weight. The PEs on the list are iterated to setup
their TCE32 tables at system booting time. The list is used for
once at boot time and no need to keep it.

This moves the logic calculating DMA32 weight of PHB and PE to
pnv_ioda_setup_dma() to drop PHB's DMA32 list. Also, every PE
traces the consumed DMA32 segment by @tce32_seg and @tce32_segcount
are useless and they're removed.
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

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

@@ -890,44 +890,6 @@ static int pnv_ioda_configure_pe(struct pnv_phb *phb, struct pnv_ioda_pe *pe)
 	return 0;
 }
 
-static void pnv_ioda_link_pe_by_weight(struct pnv_phb *phb,
-				       struct pnv_ioda_pe *pe)
-{
-	struct pnv_ioda_pe *lpe;
-
-	list_for_each_entry(lpe, &phb->ioda.pe_dma_list, dma_link) {
-		if (lpe->dma_weight < pe->dma_weight) {
-			list_add_tail(&pe->dma_link, &lpe->dma_link);
-			return;
-		}
-	}
-	list_add_tail(&pe->dma_link, &phb->ioda.pe_dma_list);
-}
-
-static unsigned int pnv_ioda_dma_weight(struct pci_dev *dev)
-{
-	/* This is quite simplistic. The "base" weight of a device
-	 * is 10. 0 means no DMA is to be accounted for it.
-	 */
-
-	/* If it's a bridge, no DMA */
-	if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
-		return 0;
-
-	/* Reduce the weight of slow USB controllers */
-	if (dev->class == PCI_CLASS_SERIAL_USB_UHCI ||
-	    dev->class == PCI_CLASS_SERIAL_USB_OHCI ||
-	    dev->class == PCI_CLASS_SERIAL_USB_EHCI)
-		return 3;
-
-	/* Increase the weight of RAID (includes Obsidian) */
-	if ((dev->class >> 8) == PCI_CLASS_STORAGE_RAID)
-		return 15;
-
-	/* Default */
-	return 10;
-}
-
 #ifdef CONFIG_PCI_IOV
 static int pnv_pci_vf_resource_shift(struct pci_dev *dev, int offset)
 {
@@ -1032,7 +994,6 @@ static struct pnv_ioda_pe *pnv_ioda_setup_dev_PE(struct pci_dev *dev)
 	pe->flags = PNV_IODA_PE_DEV;
 	pe->pdev = dev;
 	pe->pbus = NULL;
-	pe->tce32_seg = -1;
 	pe->mve_number = -1;
 	pe->rid = dev->bus->number << 8 | pdn->devfn;
 
@@ -1048,16 +1009,6 @@ static struct pnv_ioda_pe *pnv_ioda_setup_dev_PE(struct pci_dev *dev)
 		return NULL;
 	}
 
-	/* Assign a DMA weight to the device */
-	pe->dma_weight = pnv_ioda_dma_weight(dev);
-	if (pe->dma_weight != 0) {
-		phb->ioda.dma_weight += pe->dma_weight;
-		phb->ioda.dma_pe_count++;
-	}
-
-	/* Link the PE */
-	pnv_ioda_link_pe_by_weight(phb, pe);
-
 	return pe;
 }
 
@@ -1075,7 +1026,6 @@ static void pnv_ioda_setup_same_PE(struct pci_bus *bus, struct pnv_ioda_pe *pe)
 		}
 		pdn->pcidev = dev;
 		pdn->pe_number = pe->pe_number;
-		pe->dma_weight += pnv_ioda_dma_weight(dev);
 		if ((pe->flags & PNV_IODA_PE_BUS_ALL) && dev->subordinate)
 			pnv_ioda_setup_same_PE(dev->subordinate, pe);
 	}
@@ -1112,10 +1062,8 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
 	pe->flags |= (all ? PNV_IODA_PE_BUS_ALL : PNV_IODA_PE_BUS);
 	pe->pbus = bus;
 	pe->pdev = NULL;
-	pe->tce32_seg = -1;
 	pe->mve_number = -1;
 	pe->rid = bus->busn_res.start << 8;
-	pe->dma_weight = 0;
 
 	if (all)
 		pe_info(pe, "Secondary bus %d..%d associated with PE#%d\n",
@@ -1137,17 +1085,6 @@ static void pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
 
 	/* Put PE to the list */
 	list_add_tail(&pe->list, &phb->ioda.pe_list);
-
-	/* Account for one DMA PE if at least one DMA capable device exist
-	 * below the bridge
-	 */
-	if (pe->dma_weight != 0) {
-		phb->ioda.dma_weight += pe->dma_weight;
-		phb->ioda.dma_pe_count++;
-	}
-
-	/* Link the PE */
-	pnv_ioda_link_pe_by_weight(phb, pe);
 }
 
 static struct pnv_ioda_pe *pnv_ioda_setup_npu_PE(struct pci_dev *npu_pdev)
@@ -1188,7 +1125,6 @@ static struct pnv_ioda_pe *pnv_ioda_setup_npu_PE(struct pci_dev *npu_pdev)
 			rid = npu_pdev->bus->number << 8 | npu_pdn->devfn;
 			npu_pdn->pcidev = npu_pdev;
 			npu_pdn->pe_number = pe_num;
-			pe->dma_weight += pnv_ioda_dma_weight(npu_pdev);
 			phb->ioda.pe_rmap[rid] = pe->pe_number;
 
 			/* Map the PE to this link */
@@ -1536,7 +1472,6 @@ static void pnv_ioda_setup_vf_PE(struct pci_dev *pdev, u16 num_vfs)
 		pe->flags = PNV_IODA_PE_VF;
 		pe->pbus = NULL;
 		pe->parent_dev = pdev;
-		pe->tce32_seg = -1;
 		pe->mve_number = -1;
 		pe->rid = (pci_iov_virtfn_bus(pdev, vf_index) << 8) |
 			   pci_iov_virtfn_devfn(pdev, vf_index);
@@ -2027,6 +1962,54 @@ static struct iommu_table_ops pnv_ioda2_iommu_ops = {
 	.free = pnv_ioda2_table_free,
 };
 
+static int pnv_pci_ioda_dev_dma_weight(struct pci_dev *dev, void *data)
+{
+	unsigned int *weight = (unsigned int *)data;
+
+	/* This is quite simplistic. The "base" weight of a device
+	 * is 10. 0 means no DMA is to be accounted for it.
+	 */
+	if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL)
+		return 0;
+
+	if (dev->class == PCI_CLASS_SERIAL_USB_UHCI ||
+	    dev->class == PCI_CLASS_SERIAL_USB_OHCI ||
+	    dev->class == PCI_CLASS_SERIAL_USB_EHCI)
+		*weight += 3;
+	else if ((dev->class >> 8) == PCI_CLASS_STORAGE_RAID)
+		*weight += 15;
+	else
+		*weight += 10;
+
+	return 0;
+}
+
+static unsigned int pnv_pci_ioda_pe_dma_weight(struct pnv_ioda_pe *pe)
+{
+	unsigned int weight = 0;
+
+	/* SRIOV VF has same DMA32 weight as its PF */
+#ifdef CONFIG_PCI_IOV
+	if ((pe->flags & PNV_IODA_PE_VF) && pe->parent_dev) {
+		pnv_pci_ioda_dev_dma_weight(pe->parent_dev, &weight);
+		return weight;
+	}
+#endif
+
+	if ((pe->flags & PNV_IODA_PE_DEV) && pe->pdev) {
+		pnv_pci_ioda_dev_dma_weight(pe->pdev, &weight);
+	} else if ((pe->flags & PNV_IODA_PE_BUS) && pe->pbus) {
+		struct pci_dev *pdev;
+
+		list_for_each_entry(pdev, &pe->pbus->devices, bus_list)
+			pnv_pci_ioda_dev_dma_weight(pdev, &weight);
+	} else if ((pe->flags & PNV_IODA_PE_BUS_ALL) && pe->pbus) {
+		pci_walk_bus(pe->pbus, pnv_pci_ioda_dev_dma_weight, &weight);
+	}
+
+	return weight;
+}
+
 static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb,
 				       struct pnv_ioda_pe *pe,
 				       unsigned int base,
@@ -2043,17 +2026,12 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb,
 	/* XXX FIXME: Provide 64-bit DMA facilities & non-4K TCE tables etc.. */
 	/* XXX FIXME: Allocate multi-level tables on PHB3 */
 
-	/* We shouldn't already have a 32-bit DMA associated */
-	if (WARN_ON(pe->tce32_seg >= 0))
-		return;
-
 	tbl = pnv_pci_table_alloc(phb->hose->node);
 	iommu_register_group(&pe->table_group, phb->hose->global_number,
 			pe->pe_number);
 	pnv_pci_link_table_and_group(phb->hose->node, 0, tbl, &pe->table_group);
 
 	/* Grab a 32-bit TCE table */
-	pe->tce32_seg = base;
 	pe_info(pe, " Setting up 32-bit TCE table at %08x..%08x\n",
 		base * PNV_IODA1_DMA32_SEGSIZE,
 		(base + segs) * PNV_IODA1_DMA32_SEGSIZE - 1);
@@ -2120,8 +2098,6 @@ static void pnv_pci_ioda1_setup_dma_pe(struct pnv_phb *phb,
 	return;
  fail:
 	/* XXX Failure: Try to fallback to 64-bit only ? */
-	if (pe->tce32_seg >= 0)
-		pe->tce32_seg = -1;
 	if (tce_mem)
 		__free_pages(tce_mem, get_order(tce32_segsz * segs));
 	if (tbl) {
@@ -2532,10 +2508,6 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 {
 	int64_t rc;
 
-	/* We shouldn't already have a 32-bit DMA associated */
-	if (WARN_ON(pe->tce32_seg >= 0))
-		return;
-
 	/* TVE #1 is selected by PCI address bit 59 */
 	pe->tce_bypass_base = 1ull << 59;
 
@@ -2543,7 +2515,6 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 			pe->pe_number);
 
 	/* The PE will reserve all possible 32-bits space */
-	pe->tce32_seg = 0;
 	pe_info(pe, "Setting up 32-bit TCE table at 0..%08x\n",
 		phb->ioda.m32_pci_base);
 
@@ -2559,11 +2530,8 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 #endif
 
 	rc = pnv_pci_ioda2_setup_default_config(pe);
-	if (rc) {
-		if (pe->tce32_seg >= 0)
-			pe->tce32_seg = -1;
+	if (rc)
 		return;
-	}
 
 	if (pe->flags & PNV_IODA_PE_DEV)
 		iommu_add_device(&pe->pdev->dev);
@@ -2574,24 +2542,35 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 static void pnv_ioda_setup_dma(struct pnv_phb *phb)
 {
 	struct pci_controller *hose = phb->hose;
-	unsigned int residual, remaining, segs, tw, base;
+	unsigned int weight, total_weight, dma_pe_count;
+	unsigned int residual, remaining, segs, base;
 	struct pnv_ioda_pe *pe;
 
+	total_weight = 0;
+	pci_walk_bus(phb->hose->bus, pnv_pci_ioda_dev_dma_weight,
+		     &total_weight);
+
+	dma_pe_count = 0;
+	list_for_each_entry(pe, &phb->ioda.pe_list, list) {
+		weight = pnv_pci_ioda_pe_dma_weight(pe);
+		if (weight > 0)
+			dma_pe_count++;
+	}
+
 	/* If we have more PE# than segments available, hand out one
 	 * per PE until we run out and let the rest fail. If not,
 	 * then we assign at least one segment per PE, plus more based
 	 * on the amount of devices under that PE
 	 */
-	if (phb->ioda.dma_pe_count > phb->ioda.tce32_count)
+	if (dma_pe_count > phb->ioda.tce32_count)
 		residual = 0;
 	else
-		residual = phb->ioda.tce32_count -
-			phb->ioda.dma_pe_count;
+		residual = phb->ioda.tce32_count - dma_pe_count;
 
 	pr_info("PCI: Domain %04x has %ld available 32-bit DMA segments\n",
 		hose->global_number, phb->ioda.tce32_count);
 	pr_info("PCI: %d PE# for a total weight of %d\n",
-		phb->ioda.dma_pe_count, phb->ioda.dma_weight);
+		dma_pe_count, total_weight);
 
 	pnv_pci_ioda_setup_opal_tce_kill(phb);
 
@@ -2600,18 +2579,20 @@ static void pnv_ioda_setup_dma(struct pnv_phb *phb)
 	 * weight
 	 */
 	remaining = phb->ioda.tce32_count;
-	tw = phb->ioda.dma_weight;
 	base = 0;
-	list_for_each_entry(pe, &phb->ioda.pe_dma_list, dma_link) {
-		if (!pe->dma_weight)
+	list_for_each_entry(pe, &phb->ioda.pe_list, list) {
+		weight = pnv_pci_ioda_pe_dma_weight(pe);
+		if (!weight)
 			continue;
+
 		if (!remaining) {
 			pe_warn(pe, "No DMA32 resources available\n");
 			continue;
 		}
 		segs = 1;
 		if (residual) {
-			segs += ((pe->dma_weight * residual)  + (tw / 2)) / tw;
+			segs += ((weight * residual) + (total_weight / 2)) /
+				total_weight;
 			if (segs > remaining)
 				segs = remaining;
 		}
@@ -2623,7 +2604,7 @@ static void pnv_ioda_setup_dma(struct pnv_phb *phb)
 		 */
 		if (phb->type == PNV_PHB_IODA1) {
 			pe_info(pe, "DMA weight %d, assigned %d DMA32 segments\n",
-				pe->dma_weight, segs);
+				weight, segs);
 			pnv_pci_ioda1_setup_dma_pe(phb, pe, base, segs);
 		} else if (phb->type == PNV_PHB_IODA2) {
 			pe_info(pe, "Assign DMA32 space\n");
@@ -3167,13 +3148,18 @@ static void pnv_npu_ioda_fixup(void)
 	struct pci_controller *hose, *tmp;
 	struct pnv_phb *phb;
 	struct pnv_ioda_pe *pe;
+	unsigned int weight;
 
 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
 		phb = hose->private_data;
 		if (phb->type != PNV_PHB_NPU)
 			continue;
 
-		list_for_each_entry(pe, &phb->ioda.pe_dma_list, dma_link) {
+		list_for_each_entry(pe, &phb->ioda.pe_list, list) {
+			weight = pnv_pci_ioda_pe_dma_weight(pe);
+			if (WARN_ON(!weight))
+				continue;
+
 			enable_bypass = dma_get_mask(&pe->pdev->dev) ==
 				DMA_BIT_MASK(64);
 			pnv_npu_init_dma_pe(pe);
@@ -3455,7 +3441,6 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 	phb->ioda.pe_array = aux + pemap_off;
 	set_bit(phb->ioda.reserved_pe_idx, phb->ioda.pe_alloc);
 
-	INIT_LIST_HEAD(&phb->ioda.pe_dma_list);
 	INIT_LIST_HEAD(&phb->ioda.pe_list);
 	mutex_init(&phb->ioda.pe_list_mutex);
 

arch/powerpc/platforms/powernv/pci.h

@@ -53,14 +53,7 @@ struct pnv_ioda_pe {
 	/* PE number */
 	unsigned int		pe_number;
 
-	/* "Weight" assigned to the PE for the sake of DMA resource
-	 * allocations
-	 */
-	unsigned int		dma_weight;
-
 	/* "Base" iommu table, ie, 4K TCEs, 32-bit DMA */
-	int			tce32_seg;
-	int			tce32_segcount;
 	struct iommu_table_group table_group;
 
 	/* 64-bit TCE bypass region */
@@ -78,7 +71,6 @@ struct pnv_ioda_pe {
 	struct list_head	slaves;
 
 	/* Link in list of PE#s */
-	struct list_head	dma_link;
 	struct list_head	list;
 };
 
@@ -169,17 +161,6 @@ struct pnv_phb {
 		/* 32-bit TCE tables allocation */
 		unsigned long		tce32_count;
 
-		/* Total "weight" for the sake of DMA resources
-		 * allocation
-		 */
-		unsigned int		dma_weight;
-		unsigned int		dma_pe_count;
-
-		/* Sorted list of used PE's, sorted at
-		 * boot for resource allocation purposes
-		 */
-		struct list_head	pe_dma_list;
-
 		/* TCE cache invalidate registers (physical and
 		 * remapped)
 		 */