PCI: Keep individual VF BAR size in struct pci_sriov

Currently we don't store the individual VF BAR size.  We calculate it when
needed by dividing the PF's IOV resource size (which contains space for
*all* the VFs) by total_VFs or by reading the BAR in the SR-IOV capability
again.

Keep the individual VF BAR size in struct pci_sriov.barsz[], add
pci_iov_resource_size() to retrieve it, and use that instead of doing the
division or reading the SR-IOV capability BAR.

[bhelgaas: rename to "barsz[]", simplify barsz[] index computation, remove
SR-IOV capability BAR sizing]
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 21 insertions, 19 deletions

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 05f9d97e4175..5bca0e1a2799 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -57,6 +57,14 @@ static void virtfn_remove_bus(struct pci_bus *physbus, struct pci_bus *virtbus)
                 pci_remove_bus(virtbus);
 }
 
+resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno)
+{
+        if (!dev->is_physfn)
+                return 0;
+
+        return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
+}
+
 static int virtfn_add(struct pci_dev *dev, int id, int reset)
 {
         int i;
@@ -92,8 +100,7 @@ static int virtfn_add(struct pci_dev *dev, int id, int reset)
                         continue;
                 virtfn->resource[i].name = pci_name(virtfn);
                 virtfn->resource[i].flags = res->flags;
-                size = resource_size(res);
-                do_div(size, iov->total_VFs);
+                size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
                 virtfn->resource[i].start = res->start + size * id;
                 virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
                 rc = request_resource(res, &virtfn->resource[i]);
@@ -311,7 +318,7 @@ static void sriov_disable(struct pci_dev *dev)
 
 static int sriov_init(struct pci_dev *dev, int pos)
 {
-        int i;
+        int i, bar64;
         int rc;
         int nres;
         u32 pgsz;
@@ -360,29 +367,29 @@ found:
         pgsz &= ~(pgsz - 1);
         pci_write_config_dword(dev, pos + PCI_SRIOV_SYS_PGSIZE, pgsz);
 
+        iov = kzalloc(sizeof(*iov), GFP_KERNEL);
+        if (!iov)
+                return -ENOMEM;
+
         nres = 0;
         for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
                 res = dev->resource + PCI_IOV_RESOURCES + i;
-                i += __pci_read_base(dev, pci_bar_unknown, res,
-                                     pos + PCI_SRIOV_BAR + i * 4);
+                bar64 = __pci_read_base(dev, pci_bar_unknown, res,
+                                        pos + PCI_SRIOV_BAR + i * 4);
                 if (!res->flags)
                         continue;
                 if (resource_size(res) & (PAGE_SIZE - 1)) {
                         rc = -EIO;
                         goto failed;
                 }
+                iov->barsz[i] = resource_size(res);
                 res->end = res->start + resource_size(res) * total - 1;
                 dev_info(&dev->dev, "VF(n) BAR%d space: %pR (contains BAR%d for %d VFs)\n",
                          i, res, i, total);
+                i += bar64;
                 nres++;
         }
 
-        iov = kzalloc(sizeof(*iov), GFP_KERNEL);
-        if (!iov) {
-                rc = -ENOMEM;
-                goto failed;
-        }
-
         iov->pos = pos;
         iov->nres = nres;
         iov->ctrl = ctrl;
@@ -414,6 +421,7 @@ failed:
                 res->flags = 0;
         }
 
+        kfree(iov);
         return rc;
 }
 
@@ -510,14 +518,7 @@ int pci_iov_resource_bar(struct pci_dev *dev, int resno)
  */
 resource_size_t pci_sriov_resource_alignment(struct pci_dev *dev, int resno)
 {
-        struct resource tmp;
-        int reg = pci_iov_resource_bar(dev, resno);
-
-        if (!reg)
-                return 0;
-
-         __pci_read_base(dev, pci_bar_unknown, &tmp, reg);
-        return resource_alignment(&tmp);
+        return pci_iov_resource_size(dev, resno);
 }
 
 /**
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 4091f82239cd..57329645dd01 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -247,6 +247,7 @@ struct pci_sriov {
         struct pci_dev *dev;    /* lowest numbered PF */
         struct pci_dev *self;   /* this PF */
         struct mutex lock;      /* lock for VF bus */
+        resource_size_t barsz[PCI_SRIOV_NUM_BARS];      /* VF BAR size */
 };
 
 #ifdef CONFIG_PCI_ATS