USB: xhci: Performance - move interrupt handlers into xhci-ring.c

Most of the work for interrupt handling is done in xhci-ring.c, so it makes
sense to move the functions that are first called when an interrupt happens
(xhci_irq() or xhci_msi_irq()) into xhci-ring.c, so that the compiler can better
optimize them.

Shorten some lines to make it pass checkpatch.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 103 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 7f1c54585b63..4b50a02ba114 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -2030,6 +2030,109 @@ void xhci_handle_event(struct xhci_hcd *xhci)
         /* Are there more items on the event ring? */
         xhci_handle_event(xhci);
 }
+/*
+ * Called in interrupt context when there might be work
+ * queued on the event ring
+ *
+ * xhci->lock must be held by caller.
+ */
+static void xhci_work(struct xhci_hcd *xhci)
+{
+        u32 temp;
+        u64 temp_64;
+
+        /*
+         * Clear the op reg interrupt status first,
+         * so we can receive interrupts from other MSI-X interrupters.
+         * Write 1 to clear the interrupt status.
+         */
+        temp = xhci_readl(xhci, &xhci->op_regs->status);
+        temp |= STS_EINT;
+        xhci_writel(xhci, temp, &xhci->op_regs->status);
+        /* FIXME when MSI-X is supported and there are multiple vectors */
+        /* Clear the MSI-X event interrupt status */
+
+        /* Acknowledge the interrupt */
+        temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
+        temp |= 0x3;
+        xhci_writel(xhci, temp, &xhci->ir_set->irq_pending);
+
+        if (xhci->xhc_state & XHCI_STATE_DYING)
+                xhci_dbg(xhci, "xHCI dying, ignoring interrupt. "
+                                "Shouldn't IRQs be disabled?\n");
+        else
+                /* FIXME this should be a delayed service routine
+                 * that clears the EHB.
+                 */
+                xhci_handle_event(xhci);
+
+        /* Clear the event handler busy flag (RW1C); event ring is empty. */
+        temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+        xhci_write_64(xhci, temp_64 | ERST_EHB, &xhci->ir_set->erst_dequeue);
+        /* Flush posted writes -- FIXME is this necessary? */
+        xhci_readl(xhci, &xhci->ir_set->irq_pending);
+}
+
+/*
+ * xHCI spec says we can get an interrupt, and if the HC has an error condition,
+ * we might get bad data out of the event ring.  Section 4.10.2.7 has a list of
+ * indicators of an event TRB error, but we check the status *first* to be safe.
+ */
+irqreturn_t xhci_irq(struct usb_hcd *hcd)
+{
+        struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+        u32 temp, temp2;
+        union xhci_trb *trb;
+
+        spin_lock(&xhci->lock);
+        trb = xhci->event_ring->dequeue;
+        /* Check if the xHC generated the interrupt, or the irq is shared */
+        temp = xhci_readl(xhci, &xhci->op_regs->status);
+        temp2 = xhci_readl(xhci, &xhci->ir_set->irq_pending);
+        if (temp == 0xffffffff && temp2 == 0xffffffff)
+                goto hw_died;
+
+        if (!(temp & STS_EINT) && !ER_IRQ_PENDING(temp2)) {
+                spin_unlock(&xhci->lock);
+                xhci_warn(xhci, "Spurious interrupt.\n");
+                return IRQ_NONE;
+        }
+        xhci_dbg(xhci, "op reg status = %08x\n", temp);
+        xhci_dbg(xhci, "ir set irq_pending = %08x\n", temp2);
+        xhci_dbg(xhci, "Event ring dequeue ptr:\n");
+        xhci_dbg(xhci, "@%llx %08x %08x %08x %08x\n",
+                        (unsigned long long)
+                        xhci_trb_virt_to_dma(xhci->event_ring->deq_seg, trb),
+                        lower_32_bits(trb->link.segment_ptr),
+                        upper_32_bits(trb->link.segment_ptr),
+                        (unsigned int) trb->link.intr_target,
+                        (unsigned int) trb->link.control);
+
+        if (temp & STS_FATAL) {
+                xhci_warn(xhci, "WARNING: Host System Error\n");
+                xhci_halt(xhci);
+hw_died:
+                xhci_to_hcd(xhci)->state = HC_STATE_HALT;
+                spin_unlock(&xhci->lock);
+                return -ESHUTDOWN;
+        }
+
+        xhci_work(xhci);
+        spin_unlock(&xhci->lock);
+
+        return IRQ_HANDLED;
+}
+
+irqreturn_t xhci_msi_irq(int irq, struct usb_hcd *hcd)
+{
+        irqreturn_t ret;
+
+        set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+
+        ret = xhci_irq(hcd);
+
+        return ret;
+}
 
 /****           Endpoint Ring Operations        ****/