[PATCH v6 07/42] powerpc/powernv: Improve IO and M32 mapping

[Gavin Shan]

There're 3 windows (IO, M32 and M64) for PHB, root port and upstream
port of the PCIE switch behind root port. In order to support PCI
hotplug, we extend the start/end address of those 3 windows of root
port or upstream port to the start/end address of the 3 PHB's windows.
The current implementation, assigning IO or M32 segment based on the
bridge's windows, isn't reliable.

The patch fixes above issue by calculating PE's consumed IO or M32
segments from its contained devices, no PCI bridge windows involved
if the PE doesn't contain all the subordinate PCI buses. Otherwise,
the PCI bridge windows still contribute to PE's consumed IO or M32
segments.

Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
---
 arch/powerpc/platforms/powernv/pci-ioda.c | 136 +++++++++++++++++-------------
 1 file changed, 79 insertions(+), 57 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 488a53e..713f4b4 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -2844,75 +2844,97 @@ static void pnv_pci_ioda_fixup_iov_resources(struct pci_dev *pdev)
 }
 #endif /* CONFIG_PCI_IOV */
 
-/*
- * This function is supposed to be called on basis of PE from top
- * to bottom style. So the the I/O or MMIO segment assigned to
- * parent PE could be overrided by its child PEs if necessary.
- */
-static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
-				  struct pnv_ioda_pe *pe)
+static int pnv_ioda_setup_one_res(struct pci_controller *hose,
+				  struct pnv_ioda_pe *pe,
+				  struct resource *res)
 {
 	struct pnv_phb *phb = hose->private_data;
 	struct pci_bus_region region;
-	struct resource *res;
-	int i, index;
-	unsigned int segsize;
+	unsigned int index, segsize;
 	unsigned long *segmap, *pe_segmap;
 	uint16_t win;
 	int64_t rc;
 
-	/*
-	 * NOTE: We only care PCI bus based PE for now. For PCI
-	 * device based PE, for example SRIOV sensitive VF should
-	 * be figured out later.
-	 */
-	BUG_ON(!(pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL)));
+	/* Check if we need map the resource */
+	if (!res->parent || !res->flags || res->start > res->end)
+		return 0;
 
-	pci_bus_for_each_resource(pe->pbus, res, i) {
-		if (!res || !res->flags ||
-		    res->start > res->end)
-			continue;
+	if (res->flags & IORESOURCE_IO) {
+		region.start = res->start - phb->ioda.io_pci_base;
+		region.end   = res->end - phb->ioda.io_pci_base;
+		segsize      = phb->ioda.io_segsize;
+		segmap       = phb->ioda.io_segmap;
+		pe_segmap    = pe->io_segmap;
+		win          = OPAL_IO_WINDOW_TYPE;
+	} else if ((res->flags & IORESOURCE_MEM) &&
+		   !pnv_pci_is_mem_pref_64(res->flags)) {
+		region.start = res->start -
+			       hose->mem_offset[0] -
+			       phb->ioda.m32_pci_base;
+		region.end   = res->end -
+			       hose->mem_offset[0] -
+			       phb->ioda.m32_pci_base;
+		segsize      = phb->ioda.m32_segsize;
+		segmap       = phb->ioda.m32_segmap;
+		pe_segmap    = pe->m32_segmap;
+		win          = OPAL_M32_WINDOW_TYPE;
+	} else {
+		return 0;
+	}
 
-		if (res->flags & IORESOURCE_IO) {
-			region.start = res->start - phb->ioda.io_pci_base;
-			region.end   = res->end - phb->ioda.io_pci_base;
-			segsize      = phb->ioda.io_segsize;
-			segmap       = phb->ioda.io_segmap;
-			pe_segmap    = pe->io_segmap;
-			win          = OPAL_IO_WINDOW_TYPE;
-		} else if ((res->flags & IORESOURCE_MEM) &&
-			   !pnv_pci_is_mem_pref_64(res->flags)) {
-			region.start = res->start -
-				       hose->mem_offset[0] -
-				       phb->ioda.m32_pci_base;
-			region.end   = res->end -
-				       hose->mem_offset[0] -
-				       phb->ioda.m32_pci_base;
-			segsize      = phb->ioda.m32_segsize;
-			segmap       = phb->ioda.m32_segmap;
-			pe_segmap    = pe->m32_segmap;
-			win          = OPAL_M32_WINDOW_TYPE;
-		} else {
-			continue;
+	region.start = _ALIGN_DOWN(region.start, segsize);
+	region.end   = _ALIGN_UP(region.end, segsize);
+	index = region.start / segsize;
+	while (index < phb->ioda.total_pe &&
+	       region.start < region.end) {
+		rc = opal_pci_map_pe_mmio_window(phb->opal_id,
+				pe->pe_number, win, 0, index);
+		if (rc != OPAL_SUCCESS) {
+			pr_warn("%s: Error %lld mapping (%d) seg#%d to PHB#%d-PE#%d\n",
+				__func__, rc, win, index,
+				pe->phb->hose->global_number,
+				pe->pe_number);
+			return -EIO;
 		}
 
-		index = region.start / phb->ioda.io_segsize;
-		while (index < phb->ioda.total_pe &&
-		       region.start <= region.end) {
-			set_bit(index, segmap);
-			set_bit(index, pe_segmap);
-			rc = opal_pci_map_pe_mmio_window(phb->opal_id,
-					pe->pe_number, win, 0, index);
-			if (rc != OPAL_SUCCESS) {
-				pr_warn("%s: Error %lld mapping (%d) seg#%d to PHB#%d-PE#%d\n",
-					__func__, rc, win, index,
-					pe->phb->hose->global_number,
-					pe->pe_number);
-				break;
-			}
+		set_bit(index, segmap);
+		set_bit(index, pe_segmap);
+		region.start += segsize;
+		index++;
+	}
+
+	return 0;
+}
+
+static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
+				  struct pnv_ioda_pe *pe)
+{
+	struct pci_dev *pdev;
+	struct resource *res;
+	int i;
+
+	/* This function only works for bus dependent PE */
+	BUG_ON(!(pe->flags & (PNV_IODA_PE_BUS | PNV_IODA_PE_BUS_ALL)));
+
+	list_for_each_entry(pdev, &pe->pbus->devices, bus_list) {
+		for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
+			res = &pdev->resource[i];
+			if (pnv_ioda_setup_one_res(hose, pe, res))
+				return;
+		}
+
+		/* If the PE contains all subordinate PCI buses, the
+		 * resources of the child bridges should be mapped
+		 * to the PE as well.
+		 */
+		if (!(pe->flags & PNV_IODA_PE_BUS_ALL) ||
+		    (pdev->class >> 8) != PCI_CLASS_BRIDGE_PCI)
+			continue;
 
-			region.start += segsize;
-			index++;
+		for (i = 0; i <= PCI_BRIDGE_RESOURCE_NUM; i++) {
+			res = &pdev->resource[PCI_BRIDGE_RESOURCES + i];
+			if (pnv_ioda_setup_one_res(hose, pe, res))
+				return;
 		}
 	}
 }
-- 
2.1.0