xhci: Change hcd_priv into a pointer.

Instead of allocating space for the whole xhci_hcd structure at the end of
usb_hcd, make the USB core allocate enough space for a pointer to the
xhci_hcd structure.  This will make it easy to share the xhci_hcd
structure across the two roothubs (the USB 3.0 usb_hcd and the USB 2.0
usb_hcd).

Deallocate the xhci_hcd at PCI remove time, so the hcd_priv will be
deallocated after the usb_hcd is deallocated.  We do this by registering a
different PCI remove function that calls the usb_hcd_pci_remove()
function, and then frees the xhci_hcd.  usb_hcd_pci_remove() calls
kput() on the usb_hcd structure, which will deallocate the memory that
contains the hcd_priv pointer, but not the memory it points to.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>

2 files changed, 30 insertions, 8 deletions

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index bb668a894ab9..009082829364 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -57,6 +57,12 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
 
         hcd->self.sg_tablesize = TRBS_PER_SEGMENT - 2;
 
+        xhci = kzalloc(sizeof(struct xhci_hcd), GFP_KERNEL);
+        if (!xhci)
+                return -ENOMEM;
+        *((struct xhci_hcd **) hcd->hcd_priv) = xhci;
+        xhci->main_hcd = hcd;
+
         xhci->cap_regs = hcd->regs;
         xhci->op_regs = hcd->regs +
                 HC_LENGTH(xhci_readl(xhci, &xhci->cap_regs->hc_capbase));
@@ -85,13 +91,13 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
         /* Make sure the HC is halted. */
         retval = xhci_halt(xhci);
         if (retval)
-                return retval;
+                goto error;
 
         xhci_dbg(xhci, "Resetting HCD\n");
         /* Reset the internal HC memory state and registers. */
         retval = xhci_reset(xhci);
         if (retval)
-                return retval;
+                goto error;
         xhci_dbg(xhci, "Reset complete\n");
 
         temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
@@ -106,14 +112,29 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
         /* Initialize HCD and host controller data structures. */
         retval = xhci_init(hcd);
         if (retval)
-                return retval;
+                goto error;
         xhci_dbg(xhci, "Called HCD init\n");
 
         pci_read_config_byte(pdev, XHCI_SBRN_OFFSET, &xhci->sbrn);
         xhci_dbg(xhci, "Got SBRN %u\n", (unsigned int) xhci->sbrn);
 
         /* Find any debug ports */
-        return xhci_pci_reinit(xhci, pdev);
+        retval = xhci_pci_reinit(xhci, pdev);
+        if (!retval)
+                return retval;
+
+error:
+        kfree(xhci);
+        return retval;
+}
+
+static void xhci_pci_remove(struct pci_dev *dev)
+{
+        struct xhci_hcd *xhci;
+
+        xhci = hcd_to_xhci(pci_get_drvdata(dev));
+        usb_hcd_pci_remove(dev);
+        kfree(xhci);
 }
 
 #ifdef CONFIG_PM
@@ -143,7 +164,7 @@ static int xhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
 static const struct hc_driver xhci_pci_hc_driver = {
         .description =          hcd_name,
         .product_desc =         "xHCI Host Controller",
-        .hcd_priv_size =        sizeof(struct xhci_hcd),
+        .hcd_priv_size =        sizeof(struct xhci_hcd *),
 
         /*
          * generic hardware linkage
@@ -211,7 +232,7 @@ static struct pci_driver xhci_pci_driver = {
         .id_table =     pci_ids,
 
         .probe =        usb_hcd_pci_probe,
-        .remove =       usb_hcd_pci_remove,
+        .remove =       xhci_pci_remove,
         /* suspend and resume implemented later */
 
         .shutdown =     usb_hcd_pci_shutdown,
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index c4e70c6d809c..daa88581ad66 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1163,6 +1163,7 @@ struct s3_save {
 
 /* There is one ehci_hci structure per controller */
 struct xhci_hcd {
+        struct usb_hcd *main_hcd;
         /* glue to PCI and HCD framework */
         struct xhci_cap_regs __iomem *cap_regs;
         struct xhci_op_regs __iomem *op_regs;
@@ -1266,12 +1267,12 @@ struct xhci_hcd {
 /* convert between an HCD pointer and the corresponding EHCI_HCD */
 static inline struct xhci_hcd *hcd_to_xhci(struct usb_hcd *hcd)
 {
-        return (struct xhci_hcd *) (hcd->hcd_priv);
+        return *((struct xhci_hcd **) (hcd->hcd_priv));
 }
 
 static inline struct usb_hcd *xhci_to_hcd(struct xhci_hcd *xhci)
 {
-        return container_of((void *) xhci, struct usb_hcd, hcd_priv);
+        return xhci->main_hcd;
 }
 
 #ifdef CONFIG_USB_XHCI_HCD_DEBUGGING