>From 2bee389a863f874ef4e5f71630624cff4a37ce0c Mon Sep 17 00:00:00 2001
From: Dong Nguyen <Dong.Nguyen@xxxxxxx>
Date: Tue, 25 May 2010 18:24:07 -0700
Subject: [PATCH] xHCI: Supporting msi/msi-x
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>
---
drivers/usb/core/hcd.c | 1 +
drivers/usb/host/xhci.c | 167 +++++++++++++++++++++++++++++++++++-----------
drivers/usb/host/xhci.h | 2 +-
3 files changed, 129 insertions(+), 41 deletions(-)
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 51d95d3..ad3a7a0 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2042,6 +2042,7 @@ 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 40e0a0c..8e08643 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>
@@ -133,22 +134,96 @@ int xhci_reset(struct xhci_hcd *xhci)
return handshake(xhci, &xhci->op_regs->command, CMD_RESET, 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) {
@@ -156,20 +231,19 @@ 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);
@@ -177,21 +251,23 @@ 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).
@@ -385,21 +461,37 @@ 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;
hcd->poll_rh = 0;
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;
@@ -481,11 +573,9 @@ 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;
@@ -519,11 +609,8 @@ 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 fb3440b..a32f644 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1121,7 +1121,7 @@ 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 */
--
1.6.3.3
--
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