[v8,21/45] powerpc/powernv: Create PEs at PCI hot plugging time

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 565725b..d360607 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -197,14 +197,14 @@  static int pnv_ioda2_init_m64(struct pnv_phb *phb)
 	set_bit(phb->ioda.m64_bar_idx, &phb->ioda.m64_bar_alloc);
 
 	/*
-	 * Strip off the segment used by the reserved PE, which is
-	 * expected to be 0 or last one of PE capabicity.
+	 * Exclude the segments for reserved and root bus PE, which
+	 * are first or last two PEs.
 	 */
 	r = &phb->hose->mem_resources[1];
 	if (phb->ioda.reserved_pe_idx == 0)
-		r->start += phb->ioda.m64_segsize;
+		r->start += (2 * phb->ioda.m64_segsize);
 	else if (phb->ioda.reserved_pe_idx == (phb->ioda.total_pe_num - 1))
-		r->end -= phb->ioda.m64_segsize;
+		r->end -= (2 * phb->ioda.m64_segsize);
 	else
 		pr_warn("  Cannot strip M64 segment for reserved PE#%d\n",
 			phb->ioda.reserved_pe_idx);
@@ -284,14 +284,14 @@  static int pnv_ioda1_init_m64(struct pnv_phb *phb)
 	}
 
 	/*
-	 * Exclude the segment used by the reserved PE, which
-	 * is expected to be 0 or last supported PE#.
+	 * Exclude the segments for reserved and root bus PE, which
+	 * are first or last two PEs.
 	 */
 	r = &phb->hose->mem_resources[1];
 	if (phb->ioda.reserved_pe_idx == 0)
-		r->start += phb->ioda.m64_segsize;
+		r->start += (2 * phb->ioda.m64_segsize);
 	else if (phb->ioda.reserved_pe_idx == (phb->ioda.total_pe_num - 1))
-		r->end -= phb->ioda.m64_segsize;
+		r->end -= (2 * phb->ioda.m64_segsize);
 	else
 		pr_warn("  Cannot cut M64 segment for reserved PE#%d\n",
 			phb->ioda.reserved_pe_idx);
@@ -1022,6 +1022,15 @@  static void pnv_ioda_setup_same_PE(struct pci_bus *bus, struct pnv_ioda_pe *pe)
 				pci_name(dev));
 			continue;
 		}
+
+		/*
+		 * In partial hotplug case, the PCI device might be still
+		 * associated with the PE and needn't be attached to the
+		 * PE again.
+		 */
+		if (pdn->pe_number != IODA_INVALID_PE)
+			continue;
+
 		pdn->pcidev = dev;
 		pdn->pe_number = pe->pe_number;
 		if ((pe->flags & PNV_IODA_PE_BUS_ALL) && dev->subordinate)
@@ -1040,9 +1049,26 @@  static struct pnv_ioda_pe *pnv_ioda_setup_bus_PE(struct pci_bus *bus, bool all)
 	struct pci_controller *hose = pci_bus_to_host(bus);
 	struct pnv_phb *phb = hose->private_data;
 	struct pnv_ioda_pe *pe = NULL;
+	int pe_num;
+
+	/*
+	 * In partial hotplug case, the PE instance might be still alive.
+	 * We should reuse it instead of allocating a new one.
+	 */
+	pe_num = phb->ioda.pe_rmap[bus->number << 8];
+	if (pe_num != IODA_INVALID_PE) {
+		pe = &phb->ioda.pe_array[pe_num];
+		pnv_ioda_setup_same_PE(bus, pe);
+		return NULL;
+	}
+
+	/* PE number for root bus should have been reserved */
+	if (pci_is_root_bus(bus) &&
+	    phb->ioda.root_pe_idx != IODA_INVALID_PE)
+		pe = &phb->ioda.pe_array[phb->ioda.root_pe_idx];
 
 	/* Check if PE is determined by M64 */
-	if (phb->pick_m64_pe)
+	if (!pe && phb->pick_m64_pe)
 		pe = phb->pick_m64_pe(bus, all);
 
 	/* The PE number isn't pinned by M64 */
@@ -1154,30 +1180,6 @@  static void pnv_ioda_setup_npu_PEs(struct pci_bus *bus)
 		pnv_ioda_setup_npu_PE(pdev);
 }
 
-static void pnv_ioda_setup_PEs(struct pci_bus *bus)
-{
-	struct pci_dev *dev;
-
-	pnv_ioda_setup_bus_PE(bus, false);
-
-	list_for_each_entry(dev, &bus->devices, bus_list) {
-		if (dev->subordinate) {
-			if (pci_pcie_type(dev) == PCI_EXP_TYPE_PCI_BRIDGE)
-				pnv_ioda_setup_bus_PE(dev->subordinate, true);
-			else
-				pnv_ioda_setup_PEs(dev->subordinate);
-		}
-	}
-}
-
-/*
- * Configure PEs so that the downstream PCI buses and devices
- * could have their associated PE#. Unfortunately, we didn't
- * figure out the way to identify the PLX bridge yet. So we
- * simply put the PCI bus and the subordinate behind the root
- * port to PE# here. The game rule here is expected to be changed
- * as soon as we can detected PLX bridge correctly.
- */
 static void pnv_pci_ioda_setup_PEs(void)
 {
 	struct pci_controller *hose, *tmp;
@@ -1185,22 +1187,12 @@  static void pnv_pci_ioda_setup_PEs(void)
 
 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
 		phb = hose->private_data;
+		if (phb->type != PNV_PHB_NPU)
+			continue;
 
-		/* M64 layout might affect PE allocation */
-		if (phb->reserve_m64_pe)
-			phb->reserve_m64_pe(hose->bus, NULL, true);
-
-		/*
-		 * On NPU PHB, we expect separate PEs for individual PCI
-		 * functions. PCI bus dependent PEs are required for the
-		 * remaining types of PHBs.
-		 */
-		if (phb->type == PNV_PHB_NPU) {
-			/* PE#0 is needed for error reporting */
-			pnv_ioda_reserve_pe(phb, 0);
-			pnv_ioda_setup_npu_PEs(hose->bus);
-		} else
-			pnv_ioda_setup_PEs(hose->bus);
+		/* PE#0 is needed for error reporting */
+		pnv_ioda_reserve_pe(phb, 0);
+		pnv_ioda_setup_npu_PEs(hose->bus);
 	}
 }
 
@@ -2552,8 +2544,13 @@  static void pnv_pci_ioda2_table_free_pages(struct iommu_table *tbl)
 static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 				       struct pnv_ioda_pe *pe)
 {
+	unsigned int weight;
 	int64_t rc;
 
+	weight = pnv_pci_ioda_pe_dma_weight(pe);
+	if (!weight)
+		return;
+
 	/* TVE #1 is selected by PCI address bit 59 */
 	pe->tce_bypass_base = 1ull << 59;
 
@@ -2585,49 +2582,6 @@  static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
 		pnv_ioda_setup_bus_dma(pe, pe->pbus);
 }
 
-static void pnv_ioda_setup_dma(struct pnv_phb *phb)
-{
-	struct pci_controller *hose = phb->hose;
-	struct pnv_ioda_pe *pe;
-	unsigned int weight;
-
-	/* 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
-	 */
-	pr_info("PCI: Domain %04x has %ld available 32-bit DMA segments\n",
-		hose->global_number, phb->ioda.dma32_count);
-
-	pnv_pci_ioda_setup_opal_tce_kill(phb);
-
-	/* Walk our PE list and configure their DMA segments */
-	list_for_each_entry(pe, &phb->ioda.pe_list, list) {
-		weight = pnv_pci_ioda_pe_dma_weight(pe);
-		if (!weight)
-			continue;
-
-		/*
-		 * For IODA2 compliant PHB3, we needn't care about the weight.
-		 * The all available 32-bits DMA space will be assigned to
-		 * the specific PE.
-		 */
-		if (phb->type == PNV_PHB_IODA1) {
-			pnv_pci_ioda1_setup_dma_pe(phb, pe);
-		} else if (phb->type == PNV_PHB_IODA2) {
-			pe_info(pe, "Assign DMA32 space\n");
-			pnv_pci_ioda2_setup_dma_pe(phb, pe);
-		} else if (phb->type == PNV_PHB_NPU) {
-			/*
-			 * We initialise the DMA space for an NPU PHB
-			 * after setup of the PHB is complete as we
-			 * point the NPU TVT to the the same location
-			 * as the PHB3 TVT.
-			 */
-		}
-	}
-}
-
 #ifdef CONFIG_PCI_MSI
 static void pnv_ioda2_msi_eoi(struct irq_data *d)
 {
@@ -3087,39 +3041,6 @@  static void pnv_ioda_setup_pe_seg(struct pnv_ioda_pe *pe)
 	}
 }
 
-static void pnv_pci_ioda_setup_seg(void)
-{
-	struct pci_controller *tmp, *hose;
-	struct pnv_phb *phb;
-	struct pnv_ioda_pe *pe;
-
-	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
-		phb = hose->private_data;
-
-		/* NPU PHB does not support IO or MMIO segmentation */
-		if (phb->type == PNV_PHB_NPU)
-			continue;
-
-		list_for_each_entry(pe, &phb->ioda.pe_list, list) {
-			pnv_ioda_setup_pe_seg(pe);
-		}
-	}
-}
-
-static void pnv_pci_ioda_setup_DMA(void)
-{
-	struct pci_controller *hose, *tmp;
-	struct pnv_phb *phb;
-
-	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
-		pnv_ioda_setup_dma(hose->private_data);
-
-		/* Mark the PHB initialization done */
-		phb = hose->private_data;
-		phb->initialized = 1;
-	}
-}
-
 static void pnv_pci_ioda_create_dbgfs(void)
 {
 #ifdef CONFIG_DEBUG_FS
@@ -3130,6 +3051,9 @@  static void pnv_pci_ioda_create_dbgfs(void)
 	list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
 		phb = hose->private_data;
 
+		/* Notify initialization of PHB done */
+		phb->initialized = 1;
+
 		sprintf(name, "PCI%04x", hose->global_number);
 		phb->dbgfs = debugfs_create_dir(name, powerpc_debugfs_root);
 		if (!phb->dbgfs)
@@ -3168,9 +3092,6 @@  static void pnv_npu_ioda_fixup(void)
 static void pnv_pci_ioda_fixup(void)
 {
 	pnv_pci_ioda_setup_PEs();
-	pnv_pci_ioda_setup_seg();
-	pnv_pci_ioda_setup_DMA();
-
 	pnv_pci_ioda_create_dbgfs();
 
 #ifdef CONFIG_EEH
@@ -3223,6 +3144,104 @@  static resource_size_t pnv_pci_window_alignment(struct pci_bus *bus,
 	return phb->ioda.io_segsize;
 }
 
+/*
+ * We are updating root port or the upstream port of the
+ * bridge behind the root port with PHB's windows in order
+ * to accommodate the changes on required resources during
+ * PCI (slot) hotplug, which is connected to either root
+ * port or the downstream ports of PCIe switch behind the
+ * root port.
+ */
+static void pnv_pci_fixup_bridge_resources(struct pci_bus *bus,
+					   unsigned long type)
+{
+	struct pci_controller *hose = pci_bus_to_host(bus);
+	struct pnv_phb *phb = hose->private_data;
+	struct pci_dev *bridge = bus->self;
+	struct resource *r, *w;
+	int i;
+
+	/* Check if we need apply fixup to the bridge's windows */
+	if (!pci_is_root_bus(bridge->bus) &&
+	    !pci_is_root_bus(bridge->bus->self->bus))
+		return;
+
+	/* Fixup the resources */
+	for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) {
+		r = &bridge->resource[PCI_BRIDGE_RESOURCES + i];
+		if (!r->flags || !r->parent)
+			continue;
+
+		w = NULL;
+		if (r->flags & type & IORESOURCE_IO)
+			w = &hose->io_resource;
+		else if (pnv_pci_is_mem_pref_64(r->flags) &&
+			 (type & IORESOURCE_PREFETCH) &&
+			 phb->ioda.m64_segsize)
+			w = &hose->mem_resources[1];
+		else if (r->flags & type & IORESOURCE_MEM)
+			w = &hose->mem_resources[0];
+
+		r->start = w->start;
+		r->end = w->end;
+	}
+}
+
+static void pnv_pci_setup_bridge(struct pci_bus *bus,
+				 unsigned long type)
+{
+	struct pci_controller *hose = pci_bus_to_host(bus);
+	struct pnv_phb *phb = hose->private_data;
+	struct pci_dev *bridge = bus->self;
+	struct pnv_ioda_pe *pe;
+	bool all = (pci_pcie_type(bridge) == PCI_EXP_TYPE_PCI_BRIDGE);
+
+	 /* The PE for root bus should be realized before any one else */
+	if (!phb->ioda.root_pe_populated) {
+		pe = pnv_ioda_setup_bus_PE(phb->hose->bus, false);
+		if (pe) {
+			phb->ioda.root_pe_idx = pe->pe_number;
+			phb->ioda.root_pe_populated = true;
+		}
+	}
+
+	/* Extend bridge's windows if necessary */
+	pnv_pci_fixup_bridge_resources(bus, type);
+
+	/* Don't assign PE to PCI bus, which doesn't have subordinate devices */
+	if (list_empty(&bus->devices))
+		return;
+
+	/* Reserve PEs according to used M64 resources */
+	if (phb->reserve_m64_pe)
+		phb->reserve_m64_pe(bus, NULL, all);
+
+	/*
+	 * Assign PE. We might run here because of partial hotplug.
+	 * For the case, we just pick up the existing PE and should
+	 * not allocate resources again.
+	 */
+	pe = pnv_ioda_setup_bus_PE(bus, all);
+	if (!pe)
+		return;
+
+	/* Setup MMIO mapping */
+	pnv_ioda_setup_pe_seg(pe);
+
+	/* Setup DMA */
+	switch (phb->type) {
+	case PNV_PHB_IODA1:
+		pnv_pci_ioda1_setup_dma_pe(phb, pe);
+		break;
+	case PNV_PHB_IODA2:
+		pnv_pci_ioda2_setup_dma_pe(phb, pe);
+		break;
+	default:
+		pr_warn("%s: No DMA for PHB#%d (type %d)\n",
+			__func__, phb->hose->global_number, phb->type);
+	}
+}
+
 #ifdef CONFIG_PCI_IOV
 static resource_size_t pnv_pci_iov_resource_alignment(struct pci_dev *pdev,
 						      int resno)
@@ -3300,6 +3319,7 @@  static const struct pci_controller_ops pnv_pci_ioda_controller_ops = {
 #endif
 	.enable_device_hook	= pnv_pci_enable_device_hook,
 	.window_alignment	= pnv_pci_window_alignment,
+	.setup_bridge		= pnv_pci_setup_bridge,
 	.reset_secondary_bus	= pnv_pci_reset_secondary_bus,
 	.dma_set_mask		= pnv_pci_ioda_dma_set_mask,
 	.dma_get_required_mask	= pnv_pci_ioda_dma_get_required_mask,
@@ -3388,6 +3408,9 @@  static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 	if (phb->regs == NULL)
 		pr_err("  Failed to map registers !\n");
 
+	/* Initialize TCE kill register */
+	pnv_pci_ioda_setup_opal_tce_kill(phb);
+
 	/* Initialize more IODA stuff */
 	phb->ioda.total_pe_num = 1;
 	prop32 = of_get_property(np, "ibm,opal-num-pes", NULL);
@@ -3451,7 +3474,22 @@  static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 			phb->ioda.dma32_segmap[i] = IODA_INVALID_PE;
 	}
 	phb->ioda.pe_array = aux + pemap_off;
-	set_bit(phb->ioda.reserved_pe_idx, phb->ioda.pe_alloc);
+
+	/*
+	 * Choose PE number for root bus, which shouldn't have
+	 * M64 resources consumed by its child devices. To pick
+	 * the PE number adjacent to the reserved one if possible.
+	 */
+	pnv_ioda_reserve_pe(phb, phb->ioda.reserved_pe_idx);
+	if (phb->ioda.reserved_pe_idx == 0) {
+		phb->ioda.root_pe_idx = 1;
+		pnv_ioda_reserve_pe(phb, phb->ioda.root_pe_idx);
+	} else if (phb->ioda.reserved_pe_idx == (phb->ioda.total_pe_num - 1)) {
+		phb->ioda.root_pe_idx = phb->ioda.reserved_pe_idx - 1;
+		pnv_ioda_reserve_pe(phb, phb->ioda.root_pe_idx);
+	} else {
+		phb->ioda.root_pe_idx = IODA_INVALID_PE;
+	}
 
 	INIT_LIST_HEAD(&phb->ioda.pe_list);
 	mutex_init(&phb->ioda.pe_list_mutex);
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index ef9924a..01f2428 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -118,6 +118,8 @@  struct pnv_phb {
 		/* Global bridge info */
 		unsigned int		total_pe_num;
 		unsigned int		reserved_pe_idx;
+		unsigned int		root_pe_idx;
+		bool			root_pe_populated;
 
 		/* 32-bit MMIO window */
 		unsigned int		m32_size;