[PATCH v4 04/21] powerpc/powernv: Improve IO and M32 mapping

[Gavin Shan <gwshan@linux.vnet.ibm.com>]

The PHB's IO or M32 window is divided evenly to segments, each of
them can be mapped to arbitrary PE# by IODT or M32DT. Current code
figures out the consumed IO and M32 segments by one particular PE
from the windows of the PE's upstream bridge. It won't be reliable
once we extend M64 windows of root port, or the upstream port of
the PCIE switch behind root port to PHB's IO or M32 window, in order
to support PCI hotplug in future.

The patch improves pnv_ioda_setup_pe_seg() to calculate PE's consumed
IO or M32 segments from its contained devices, no bridge involved any
more. Also, the logic to mapping IO and M32 segments are combined to
simplify the code. Besides, it's always worthy to trace the IO and M32
segments consumed by one PE, which can be released at PCI unplugging
time.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/powernv/pci-ioda.c | 150 ++++++++++++++++--------------
 arch/powerpc/platforms/powernv/pci.h      |  13 +--
 2 files changed, 85 insertions(+), 78 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index a994882..7e6e266 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -2543,77 +2543,92 @@ 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_map_pe_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;
-	int rc;
+	unsigned int segsize, index;
+	unsigned long *segmap, *pe_segmap;
+	uint16_t win_type;
+	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 ||
+	    pnv_pci_is_mem_pref_64(res->flags))
+		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) {
+		segmap = phb->ioda.io_segmap;
+		pe_segmap = pe->io_segmap;
+		region.start = res->start - phb->ioda.io_pci_base;
+		region.end = res->end - phb->ioda.io_pci_base;
+		segsize = phb->ioda.io_segsize;
+		win_type = OPAL_IO_WINDOW_TYPE;
+	} else {
+		segmap = phb->ioda.m32_segmap;
+		pe_segmap = pe->m32_segmap;
+		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;
+		win_type = OPAL_M32_WINDOW_TYPE;
+	}
+
+	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_type, 0, index);
+		if (rc != OPAL_SUCCESS) {
+			pr_warn("%s: Error %lld mapping (%d) seg#%d to PE#%d\n",
+				__func__, rc, win_type, index, pe->pe_number);
+			return -EIO;
+		}
 
-		if (res->flags & IORESOURCE_IO) {
-			region.start = res->start - phb->ioda.io_pci_base;
-			region.end   = res->end - phb->ioda.io_pci_base;
-			index = region.start / phb->ioda.io_segsize;
+		set_bit(index, segmap);
+		set_bit(index, pe_segmap);
+		region.start += segsize;
+		index++;
+	}
 
-			while (index < phb->ioda.total_pe &&
-			       region.start <= region.end) {
-				phb->ioda.io_segmap[index] = pe->pe_number;
-				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
-					pe->pe_number, OPAL_IO_WINDOW_TYPE, 0, index);
-				if (rc != OPAL_SUCCESS) {
-					pr_err("%s: OPAL error %d when mapping IO "
-					       "segment #%d to PE#%d\n",
-					       __func__, rc, index, pe->pe_number);
-					break;
-				}
+	return 0;
+}
 
-				region.start += phb->ioda.io_segsize;
-				index++;
-			}
-		} 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;
-			index = region.start / phb->ioda.m32_segsize;
-
-			while (index < phb->ioda.total_pe &&
-			       region.start <= region.end) {
-				phb->ioda.m32_segmap[index] = pe->pe_number;
-				rc = opal_pci_map_pe_mmio_window(phb->opal_id,
-					pe->pe_number, OPAL_M32_WINDOW_TYPE, 0, index);
-				if (rc != OPAL_SUCCESS) {
-					pr_err("%s: OPAL error %d when mapping M32 "
-					       "segment#%d to PE#%d",
-					       __func__, rc, index, pe->pe_number);
-					break;
-				}
+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;
 
-				region.start += phb->ioda.m32_segsize;
-				index++;
-			}
+	/* 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_map_pe_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;
+
+		for (i = 0; i <= PCI_BRIDGE_RESOURCE_NUM; i++) {
+			res = &pdev->resource[PCI_BRIDGE_RESOURCES + i];
+			if (pnv_ioda_map_pe_one_res(hose, pe, res))
+				return;
 		}
 	}
 }
@@ -2780,7 +2795,7 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 {
 	struct pci_controller *hose;
 	struct pnv_phb *phb;
-	unsigned long size, m32map_off, pemap_off, iomap_off = 0;
+	unsigned long size, pemap_off;
 	const __be64 *prop64;
 	const __be32 *prop32;
 	int len;
@@ -2865,19 +2880,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
 
 	/* Allocate aux data & arrays. We don't have IO ports on PHB3 */
 	size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long));
-	m32map_off = size;
-	size += phb->ioda.total_pe * sizeof(phb->ioda.m32_segmap[0]);
-	if (phb->type == PNV_PHB_IODA1) {
-		iomap_off = size;
-		size += phb->ioda.total_pe * sizeof(phb->ioda.io_segmap[0]);
-	}
 	pemap_off = size;
 	size += phb->ioda.total_pe * sizeof(struct pnv_ioda_pe);
 	aux = memblock_virt_alloc(size, 0);
 	phb->ioda.pe_alloc = aux;
-	phb->ioda.m32_segmap = aux + m32map_off;
-	if (phb->type == PNV_PHB_IODA1)
-		phb->ioda.io_segmap = aux + iomap_off;
 	phb->ioda.pe_array = aux + pemap_off;
 	set_bit(phb->ioda.reserved_pe, phb->ioda.pe_alloc);
 
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 19022cf..f604bb7 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -54,6 +54,8 @@ struct pnv_ioda_pe {
 	 * by slave PEs will be contributed to the master PE. One
 	 * PE can own multiple IO and M32 segments.
 	 */
+	unsigned long		io_segmap[8];
+	unsigned long		m32_segmap[8];
 	unsigned long		m64_segmap[8];
 
 	/* "Weight" assigned to the PE for the sake of DMA resource
@@ -154,16 +156,15 @@ struct pnv_phb {
 			unsigned int		io_segsize;
 			unsigned int		io_pci_base;
 
-			/* PE allocation bitmap */
+			/* PE allocation */
+			struct pnv_ioda_pe	*pe_array;
 			unsigned long		*pe_alloc;
-			/* PE allocation mutex */
 			struct mutex		pe_alloc_mutex;
 
-			/* M32 & IO segment maps */
+			/* IO/M32/M64 segment bitmaps */
+			unsigned long		io_segmap[8];
+			unsigned long		m32_segmap[8];
 			unsigned long		m64_segmap[8];
-			unsigned int		*m32_segmap;
-			unsigned int		*io_segmap;
-			struct pnv_ioda_pe	*pe_array;
 
 			/* IRQ chip */
 			int			irq_chip_init;
-- 
2.1.0