This is a note to let you know that I've just added the patch titled
USB: xHCI: Supporting MSI/MSI-X
to my gregkh-2.6 tree which can be found in directory form at:
http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/
and in git form at:
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/patches.git
The filename of this patch is:
usb-xhci-supporting-msi-msi-x.patch
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
If this patch meets the merge guidelines for a bugfix, it should be
merged into Linus's tree before the next major kernel release.
If not, it will be merged into Linus's tree during the next merge window.
Either way, you will probably be copied on the patch when it gets sent
to Linus for merging so that others can see what is happening in kernel
development.
If you have any questions about this process, please let me know.
>From linux-usb-owner@xxxxxxxxxxxxxxx Wed Jul 21 17:18:39 2010
Subject: USB: xHCI: Supporting MSI/MSI-X
From: Dong Nguyen <Dong.Nguyen@xxxxxxx>
To: Greg KH <greg@xxxxxxxxx>
CC: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>,
"linux-usb@xxxxxxxxxxxxxxx" <linux-usb@xxxxxxxxxxxxxxx>
Date: Wed, 21 Jul 2010 16:56:08 -0700
Message-ID: <1279756568.1469.2.camel@dhnlucid>
Enable MSI/MSI-X supporting in xhci driver.
Provide the mechanism to fall back using MSI and Legacy IRQs
if MSI-X IRQs register failed.
Signed-off-by: Dong Nguyen <Dong.Nguyen@xxxxxxx>
Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>,
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2085,6 +2085,7 @@ irqreturn_t usb_hcd_irq (int irq, void *__hcd)
local_irq_restore(flags);
return rc;
}
+EXPORT_SYMBOL_GPL(usb_hcd_irq);
/*-------------------------------------------------------------------------*/
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 5e73386..3106d22 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -20,6 +20,7 @@
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
+#include <linux/pci.h>
#include <linux/irq.h>
#include <linux/log2.h>
#include <linux/module.h>
@@ -171,22 +172,95 @@ 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;
-#if 0
-/* Set up MSI-X table for entry 0 (may claim other entries later) */
-static int xhci_setup_msix(struct xhci_hcd *xhci)
+ set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+
+ ret = xhci_irq(hcd);
+
+ return ret;
+}
+
+/*
+ * Free IRQs
+ * free all IRQs request
+ */
+static void xhci_free_irq(struct xhci_hcd *xhci)
+{
+ int i;
+ struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+
+ /* return if using legacy interrupt */
+ if (xhci_to_hcd(xhci)->irq >= 0)
+ return;
+
+ if (xhci->msix_entries) {
+ for (i = 0; i < xhci->msix_count; i++)
+ if (xhci->msix_entries[i].vector)
+ free_irq(xhci->msix_entries[i].vector,
+ xhci_to_hcd(xhci));
+ } else if (pdev->irq >= 0)
+ free_irq(pdev->irq, xhci_to_hcd(xhci));
+
+ return;
+}
+
+/*
+ * Set up MSI
+ */
+static int xhci_setup_msi(struct xhci_hcd *xhci)
{
int ret;
+ struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
+
+ ret = pci_enable_msi(pdev);
+ if (ret) {
+ xhci_err(xhci, "failed to allocate MSI entry\n");
+ return ret;
+ }
+
+ ret = request_irq(pdev->irq, (irq_handler_t)xhci_msi_irq,
+ 0, "xhci_hcd", xhci_to_hcd(xhci));
+ if (ret) {
+ xhci_err(xhci, "disable MSI interrupt\n");
+ pci_disable_msi(pdev);
+ }
+
+ return ret;
+}
+
+/*
+ * Set up MSI-X
+ */
+static int xhci_setup_msix(struct xhci_hcd *xhci)
+{
+ int i, ret = 0;
struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
- xhci->msix_count = 0;
- /* XXX: did I do this right? ixgbe does kcalloc for more than one */
- xhci->msix_entries = kmalloc(sizeof(struct msix_entry), GFP_KERNEL);
+ /*
+ * calculate number of msi-x vectors supported.
+ * - HCS_MAX_INTRS: the max number of interrupts the host can handle,
+ * with max number of interrupters based on the xhci HCSPARAMS1.
+ * - num_online_cpus: maximum msi-x vectors per CPUs core.
+ * Add additional 1 vector to ensure always available interrupt.
+ */
+ xhci->msix_count = min(num_online_cpus() + 1,
+ HCS_MAX_INTRS(xhci->hcs_params1));
+
+ xhci->msix_entries =
+ kmalloc((sizeof(struct msix_entry))*xhci->msix_count,
+ GFP_KERNEL);
if (!xhci->msix_entries) {
xhci_err(xhci, "Failed to allocate MSI-X entries\n");
return -ENOMEM;
}
- xhci->msix_entries[0].entry = 0;
+
+ for (i = 0; i < xhci->msix_count; i++) {
+ xhci->msix_entries[i].entry = i;
+ xhci->msix_entries[i].vector = 0;
+ }
ret = pci_enable_msix(pdev, xhci->msix_entries, xhci->msix_count);
if (ret) {
@@ -194,20 +268,19 @@ static int xhci_setup_msix(struct xhci_hcd *xhci)
goto free_entries;
}
- /*
- * Pass the xhci pointer value as the request_irq "cookie".
- * If more irqs are added, this will need to be unique for each one.
- */
- ret = request_irq(xhci->msix_entries[0].vector, &xhci_irq, 0,
- "xHCI", xhci_to_hcd(xhci));
- if (ret) {
- xhci_err(xhci, "Failed to allocate MSI-X interrupt\n");
- goto disable_msix;
+ for (i = 0; i < xhci->msix_count; i++) {
+ ret = request_irq(xhci->msix_entries[i].vector,
+ (irq_handler_t)xhci_msi_irq,
+ 0, "xhci_hcd", xhci_to_hcd(xhci));
+ if (ret)
+ goto disable_msix;
}
- xhci_dbg(xhci, "Finished setting up MSI-X\n");
- return 0;
+
+ return ret;
disable_msix:
+ xhci_err(xhci, "disable MSI-X interrupt\n");
+ xhci_free_irq(xhci);
pci_disable_msix(pdev);
free_entries:
kfree(xhci->msix_entries);
@@ -215,21 +288,23 @@ free_entries:
return ret;
}
-/* XXX: code duplication; can xhci_setup_msix call this? */
/* Free any IRQs and disable MSI-X */
static void xhci_cleanup_msix(struct xhci_hcd *xhci)
{
struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
- if (!xhci->msix_entries)
- return;
- free_irq(xhci->msix_entries[0].vector, xhci);
- pci_disable_msix(pdev);
- kfree(xhci->msix_entries);
- xhci->msix_entries = NULL;
- xhci_dbg(xhci, "Finished cleaning up MSI-X\n");
+ xhci_free_irq(xhci);
+
+ if (xhci->msix_entries) {
+ pci_disable_msix(pdev);
+ kfree(xhci->msix_entries);
+ xhci->msix_entries = NULL;
+ } else {
+ pci_disable_msi(pdev);
+ }
+
+ return;
}
-#endif
/*
* Initialize memory for HCD and xHC (one-time init).
@@ -423,20 +498,36 @@ int xhci_run(struct usb_hcd *hcd)
{
u32 temp;
u64 temp_64;
+ u32 ret;
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
+ struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
void (*doorbell)(struct xhci_hcd *) = NULL;
hcd->uses_new_polling = 1;
xhci_dbg(xhci, "xhci_run\n");
-#if 0 /* FIXME: MSI not setup yet */
- /* Do this at the very last minute */
+ /* unregister the legacy interrupt */
+ if (hcd->irq)
+ free_irq(hcd->irq, hcd);
+ hcd->irq = -1;
+
ret = xhci_setup_msix(xhci);
- if (!ret)
- return ret;
+ if (ret)
+ /* fall back to msi*/
+ ret = xhci_setup_msi(xhci);
+
+ if (ret) {
+ /* fall back to legacy interrupt*/
+ ret = request_irq(pdev->irq, &usb_hcd_irq, IRQF_SHARED,
+ hcd->irq_descr, hcd);
+ if (ret) {
+ xhci_err(xhci, "request interrupt %d failed\n",
+ pdev->irq);
+ return ret;
+ }
+ hcd->irq = pdev->irq;
+ }
- return -ENOSYS;
-#endif
#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
init_timer(&xhci->event_ring_timer);
xhci->event_ring_timer.data = (unsigned long) xhci;
@@ -520,11 +611,9 @@ void xhci_stop(struct usb_hcd *hcd)
spin_lock_irq(&xhci->lock);
xhci_halt(xhci);
xhci_reset(xhci);
+ xhci_cleanup_msix(xhci);
spin_unlock_irq(&xhci->lock);
-#if 0 /* No MSI yet */
- xhci_cleanup_msix(xhci);
-#endif
#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
/* Tell the event ring poll function not to reschedule */
xhci->zombie = 1;
@@ -558,11 +647,8 @@ void xhci_shutdown(struct usb_hcd *hcd)
spin_lock_irq(&xhci->lock);
xhci_halt(xhci);
- spin_unlock_irq(&xhci->lock);
-
-#if 0
xhci_cleanup_msix(xhci);
-#endif
+ spin_unlock_irq(&xhci->lock);
xhci_dbg(xhci, "xhci_shutdown completed - status = %x\n",
xhci_readl(xhci, &xhci->op_regs->status));
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 6c7e343..5bc03d1 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1130,7 +1130,7 @@ struct xhci_hcd {
int page_size;
/* Valid values are 12 to 20, inclusive */
int page_shift;
- /* only one MSI vector for now, but might need more later */
+ /* msi-x vectors */
int msix_count;
struct msix_entry *msix_entries;
/* data structures */
--
1.7.0.4
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