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USB: xhci: Performance - move interrupt handlers into xhci-ring.c
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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>
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Sarah Sharp authored and Greg Kroah-Hartman committed Aug 10, 2010
1 parent 021bff9 commit 9032cd5
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Showing 3 changed files with 104 additions and 103 deletions.
103 changes: 103 additions & 0 deletions drivers/usb/host/xhci-ring.c
Original file line number Diff line number Diff line change
Expand Up @@ -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 ****/

Expand Down
103 changes: 0 additions & 103 deletions drivers/usb/host/xhci.c
Original file line number Diff line number Diff line change
Expand Up @@ -172,17 +172,6 @@ int xhci_reset(struct xhci_hcd *xhci)
return handshake(xhci, &xhci->op_regs->status, STS_CNR, 0, 250 * 1000);
}

static 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;
}

/*
* Free IRQs
* free all IRQs request
Expand Down Expand Up @@ -332,100 +321,8 @@ int xhci_init(struct usb_hcd *hcd)
return retval;
}

/*
* 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);
/* Flush posted writes */
xhci_readl(xhci, &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); the event ring should be 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);
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;
}

#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
void xhci_event_ring_work(unsigned long arg)
Expand Down
1 change: 1 addition & 0 deletions drivers/usb/host/xhci.h
Original file line number Diff line number Diff line change
Expand Up @@ -1371,6 +1371,7 @@ void xhci_stop(struct usb_hcd *hcd);
void xhci_shutdown(struct usb_hcd *hcd);
int xhci_get_frame(struct usb_hcd *hcd);
irqreturn_t xhci_irq(struct usb_hcd *hcd);
irqreturn_t xhci_msi_irq(int irq, struct usb_hcd *hcd);
int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev);
void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev);
int xhci_alloc_streams(struct usb_hcd *hcd, struct usb_device *udev,
Expand Down

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