Re: [PATCH 2/3] usb: enable pci MSI/MSIX in usb core

From: Sarah Sharp
Date: Wed Feb 22 2012 - 22:42:03 EST


On Mon, Feb 20, 2012 at 05:05:32PM +0800, Alex Shi wrote:
> MSI/MSIX is the favorite interrupt for PCIe device. PCIe usb HCD should
> be used more and more in future, but current USB core still just wants
> line IRQ, only XHCI usb driver enabled MSI/MSIX.
>
> This patch enabled pci MSI/MSIX in usb core for HCD, and removed MSI/MSIX
> setup code from XHCI since it becomes redundant now.
> There 3 places need prepare to enable MSI/MSIX in usb driver.
> 1, set HCD_MSI_FIRST in driver->flags to enable MSI/MSIX.
> 2, prepare a get_msix_num() to get msix vector numb.
> 3, prepare msi/msix_irq handler if needed.
>
> XHCI is a good example for this.
>
> Thanks for Sarah's effort on the MSI/MSIX enabling in XHCI. In fact most
> of MSI/MSIX setup functions reuse from XHCI.

Comments below.

Felipe, can you please review this patch for the effects on non-PCI
hosts? I think nothing will change, since this patchset just modifies
the USB core PCI initialization flow, but I need your eyes on this. :)

> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>
> ---
> drivers/usb/core/hcd-pci.c | 223 ++++++++++++++++++++++++++++++++++++++++++-
> drivers/usb/core/hcd.c | 22 ++++-
> drivers/usb/host/xhci-pci.c | 16 ++--
> drivers/usb/host/xhci.c | 216 +++---------------------------------------
> drivers/usb/host/xhci.h | 5 +-
> include/linux/usb/hcd.h | 17 ++++
> 6 files changed, 276 insertions(+), 223 deletions(-)
>
> diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
> index 81e2c0d..8475b25 100644
> --- a/drivers/usb/core/hcd-pci.c
> +++ b/drivers/usb/core/hcd-pci.c
> @@ -153,6 +153,218 @@ static inline void wait_for_companions(struct pci_dev *d, struct usb_hcd *h) {}
>
> /*-------------------------------------------------------------------------*/
>
> +static int hcd_free_msix(struct usb_hcd *hcd)
> +{
> + int i;
> + struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
> +
> + if (!hcd->msix_entries) {
> + printk(KERN_ERR "No msix entries found!\n");
> + return -EINVAL;
> + }
> + for (i = 0; i < hcd->msix_count; i++)
> + if (hcd->msix_entries[i].vector)
> + free_irq(hcd->msix_entries[i].vector,
> + hcd);
> +
> + pci_disable_msix(pdev);
> + kfree(hcd->msix_entries);
> + hcd->msix_entries = NULL;
> + hcd->msix_enabled = 0;
> +
> + return 0;
> +}
> +
> +static int hcd_free_msi(struct usb_hcd *hcd)
> +{
> + struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
> +
> + if (pdev->irq > 0 && hcd->irq <0)
> + free_irq(pdev->irq, hcd);
> +
> + pci_disable_msi(pdev);
> + return 0;
> +}
> +
> +/* Free and disable msi/msix */
> +void usb_hcd_free_msi_msix(struct usb_hcd *hcd)
> +{
> + if (hcd->msix_entries)
> + hcd_free_msix(hcd);
> + else
> + hcd_free_msi(hcd);
> +
> + return;
> +}
> +EXPORT_SYMBOL_GPL(usb_hcd_free_msi_msix);
> +
> +void usb_hcd_msix_sync_irqs(struct usb_hcd *hcd)
> +{
> + int i;
> + if (hcd->msix_entries) {
> + for (i = 0; i < hcd->msix_count; i++)
> + synchronize_irq(hcd->msix_entries[i].vector);
> + }
> +
> +}
> +EXPORT_SYMBOL_GPL(usb_hcd_msix_sync_irqs);
> +
> +/*
> + * Set up MSI
> + */
> +static int hcd_setup_msi(struct pci_dev *pdev, struct usb_hcd *hcd)
> +{
> + int ret;
> +
> + ret = pci_enable_msi(pdev);
> + if (ret)
> + dev_dbg(&pdev->dev, "failed to allocate MSI entry\n");
> + return ret;
> +}
> +
> +/*
> + * Set up MSI-X
> + */
> +static int hcd_setup_msix(struct pci_dev *pdev, struct usb_hcd *hcd)
> +{
> + int i, ret = 0;
> +
> + /*
> + * calculate number of msi-x vectors supported.
> + * Add additional 1 vector to ensure always available interrupt.
> + */
> + hcd->msix_count = min((int)num_online_cpus() + 1,
> + hcd->driver->get_msix_num(hcd));
> +
> + hcd->msix_entries =
> + kmalloc((sizeof(struct msix_entry))*hcd->msix_count,
> + GFP_KERNEL);
> + if (!hcd->msix_entries) {
> + dev_err(&pdev->dev, "Failed to allocate MSI-X entries\n");
> + hcd->msix_count = 0;
> + return -ENOMEM;
> + }
> +
> + for (i = 0; i < hcd->msix_count; i++) {
> + hcd->msix_entries[i].entry = i;
> + hcd->msix_entries[i].vector = 0;
> + }
> +
> + ret = pci_enable_msix(pdev, hcd->msix_entries, hcd->msix_count);
> + if (ret) {
> + dev_dbg(&pdev->dev, "Failed to enable MSI-X\n");
> + goto free_entries;
> + }
> +
> + return ret;
> +
> +free_entries:
> + kfree(hcd->msix_entries);
> + hcd->msix_entries = NULL;
> + hcd->msix_count = 0;
> + return ret;
> +}
> +
> +/* Device for a quirk */
> +#define PCI_VENDOR_ID_FRESCO_LOGIC 0x1b73
> +#define PCI_DEVICE_ID_FRESCO_LOGIC_PDK 0x1000

This PCI device and vendor ID is now used in two drivers (xhci and USB
core). Please create a separate patch to add this ID to the pci_ids.h
file, and remove the reference here and in the xHCI driver.

> +
> +/* Check for buggy HCD devices, and driver's expectation for MSI.
> + * Now, only xhci driver want it by HCD_MSI_FIRST setting. Other driver
> + * like ehci/uhci can follow this setting, if they want.
> + */
> +static int hcd_no_msi(struct pci_dev *pdev, struct usb_hcd *hcd)
> +{
> + if (pdev->vendor == PCI_VENDOR_ID_FRESCO_LOGIC &&
> + pdev->device == PCI_DEVICE_ID_FRESCO_LOGIC_PDK) {
> +
> + /* Fresco Logic confirms: all revisions of this chip do not
> + * support MSI, even though some of them claim to in their PCI
> + * capabilities.
> + */
> + dev_dbg(&pdev->dev, "QUIRK: Fresco Logic revision %u "
> + "has broken MSI implementation\n",
> + pdev->revision);
> + return 1;
> + }
> + if (!(hcd->driver->flags & HCD_MSI_FIRST))
> + return 1;
> +
> + return 0;
> +}
> +
> +/* setup msi/msix interrupts. if fails, fallback to line irq */
> +static int hcd_setup_int(struct pci_dev *pdev, struct usb_hcd *hcd)
> +{
> + int ret;
> +
> + hcd->irq = -1;
> +
> + if (!hcd_no_msi(pdev, hcd)) {

Why don't you rename hcd_no_msi() to hcd_supports_msi() and remove the
negation of the return value?

> +
> + ret = hcd_setup_msix(pdev, hcd);
> + if (ret)
> + /* fall back to msi*/
> + ret = hcd_setup_msi(pdev, hcd);
> +
> + if (!ret)
> + /* hcd->irq is -1, we have MSI */
> + return 0;
> + }
> +
> + if (!pdev->irq) {
> + dev_err(&pdev->dev, "No msi or line irq found!\n");
> + return -1;
> + }
> + /* fallback to line irq */
> + hcd->irq = pdev->irq;
> + return 0;
> +}
> +
> +int usb_hcd_request_msi_msix_irqs(struct usb_hcd *hcd, unsigned int irqnum,
> + unsigned long irqflags)
> +{
> + int retval = 1;
> + if (hcd->msix_entries && hcd->driver->msix_irq) {
> + int i;
> + /* register hc_driver's msix_irq handler */
> + for (i = 0; i < hcd->msix_count; i++) {
> + retval = request_irq(hcd->msix_entries[i].vector,
> + (irq_handler_t)hcd->driver->msix_irq,
> + 0, hcd->driver->description, hcd);

I really think you need to allow the host controller driver to set
different pointers for the msix data pointer. It's something that we
need to figure out, so that we can have the infrastructure in place for
multiple event rings.

I'm not sure whether the new get MSIX count needs to allow the xHCI
driver to return an array of pointers, or if the driver can modify the
irq pointer later? I don't think you can modify the irq data pointer
after it's been requested (that would lead to all kinds of race
conditions, I think).

It's probably better to allow the xHCI driver to pass this function the
pointers it needs for each MSI-X vector. You'll always call
usb_hcd_request_msi_msix_irqs() after you call xhci_init(), correct? At
that point, we should have allocated the multiple event rings, so it
should be easy to pass the pointers to this function.

> + if (retval) {
> + hcd_free_msix(hcd);
> + break;
> + }
> + }
> + if (i == hcd->msix_count)
> + hcd->msix_enabled = 1;
> + } else if (hcd->irq == -1 && hcd->driver->msi_irq) {
> + /* register hc_driver's msi_irq handler */
> + retval = request_irq(irqnum,
> + (irq_handler_t)hcd->driver->msi_irq,
> + 0, hcd->driver->description, hcd);
> + if (retval)
> + hcd_free_msi(hcd);
> + }
> +
> + return retval;
> +}
> +EXPORT_SYMBOL_GPL(usb_hcd_request_msi_msix_irqs);
> +
> +/* setup msi/msix interrupts and requestion irqs for them */
> +int usb_hcd_register_msi_msix_irqs(struct usb_hcd *hcd)
> +{
> + struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
> + int ret = -1;
> +
> + if (!hcd_setup_int(pdev, hcd))
> + ret = usb_hcd_request_msi_msix_irqs(hcd,
> + pdev->irq, IRQF_SHARED);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(usb_hcd_register_msi_msix_irqs);
> +
> /* configure so an HC device and id are always provided */
> /* always called with process context; sleeping is OK */
>
> @@ -187,10 +399,8 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
> return -ENODEV;
> dev->current_state = PCI_D0;
>
> - /* The xHCI driver supports MSI and MSI-X,
> - * so don't fail if the BIOS doesn't provide a legacy IRQ.
> - */
> - if (!dev->irq && (driver->flags & HCD_MASK) != HCD_USB3) {
> + /* skip irq check if hcd wants MSI firstly. */
> + if (!(driver->flags & HCD_MSI_FIRST) && !dev->irq) {
> dev_err(&dev->dev,
> "Found HC with no IRQ. Check BIOS/PCI %s setup!\n",
> pci_name(dev));
> @@ -245,6 +455,11 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
>
> pci_set_master(dev);
>
> + /* try enable MSI, if fail, seek line irq */
> + retval = hcd_setup_int(dev, hcd);
> + if (retval != 0)
> + goto unmap_registers;
> +
> retval = usb_add_hcd(hcd, dev->irq, IRQF_SHARED);
> if (retval != 0)
> goto unmap_registers;
> diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
> index e128232..579cbd3 100644
> --- a/drivers/usb/core/hcd.c
> +++ b/drivers/usb/core/hcd.c
> @@ -2322,7 +2322,7 @@ int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
> }
> EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
>
> -static int usb_hcd_request_irqs(struct usb_hcd *hcd,
> +static int usb_hcd_request_default_irqs(struct usb_hcd *hcd,
> unsigned int irqnum, unsigned long irqflags)
> {
> int retval;
> @@ -2362,6 +2362,20 @@ static int usb_hcd_request_irqs(struct usb_hcd *hcd,
> return 0;
> }
>
> +int usb_hcd_request_irqs(struct usb_hcd *hcd, unsigned int irqnum,
> + unsigned long irqflags)
> +{
> + int retval = 1;
> +
> +#ifdef CONFIG_PCI
> + retval = usb_hcd_request_msi_msix_irqs(hcd, irqnum, irqflags);
> +#endif
> + if (retval)
> + retval = usb_hcd_request_default_irqs(hcd, irqnum, irqflags);
> +
> + return retval;
> +}
> +
> /**
> * usb_add_hcd - finish generic HCD structure initialization and register
> * @hcd: the usb_hcd structure to initialize
> @@ -2447,10 +2461,8 @@ int usb_add_hcd(struct usb_hcd *hcd,
> && device_can_wakeup(&hcd->self.root_hub->dev))
> dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
>
> - /* enable irqs just before we start the controller,
> - * if the BIOS provides legacy PCI irqs.
> - */
> - if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
> + /* enable irqs just before we start the controller */
> + if (usb_hcd_is_primary_hcd(hcd)) {
> retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
> if (retval)
> goto err_request_irq;
> diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
> index ef98b38..39be795 100644
> --- a/drivers/usb/host/xhci-pci.c
> +++ b/drivers/usb/host/xhci-pci.c
> @@ -64,14 +64,6 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
> xhci_dbg(xhci, "QUIRK: Fresco Logic xHC needs configure"
> " endpoint cmd after reset endpoint\n");
> }
> - /* Fresco Logic confirms: all revisions of this chip do not
> - * support MSI, even though some of them claim to in their PCI
> - * capabilities.
> - */
> - xhci->quirks |= XHCI_BROKEN_MSI;
> - xhci_dbg(xhci, "QUIRK: Fresco Logic revision %u "
> - "has broken MSI implementation\n",
> - pdev->revision);
> }
>
> if (pdev->vendor == PCI_VENDOR_ID_NEC)
> @@ -124,6 +116,7 @@ static int xhci_pci_setup(struct usb_hcd *hcd)
> return retval;
> }
>
> +

Don't add spaces here.

> /*
> * We need to register our own PCI probe function (instead of the USB core's
> * function) in order to create a second roothub under xHCI.
> @@ -136,6 +129,7 @@ static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
> struct usb_hcd *hcd;
>
> driver = (struct hc_driver *)id->driver_data;
> +

Or here.

> /* Register the USB 2.0 roothub.
> * FIXME: USB core must know to register the USB 2.0 roothub first.
> * This is sort of silly, because we could just set the HCD driver flags
> @@ -243,13 +237,17 @@ static const struct hc_driver xhci_pci_hc_driver = {
> * generic hardware linkage
> */
> .irq = xhci_irq,
> - .flags = HCD_MEMORY | HCD_USB3 | HCD_SHARED,
> + .msi_irq = xhci_msi_irq,
> + .msix_irq = xhci_msi_irq,
> + .flags = HCD_MEMORY | HCD_USB3 | HCD_SHARED |
> + HCD_MSI_FIRST,
>
> /*
> * basic lifecycle operations
> */
> .reset = xhci_pci_setup,
> .start = xhci_run,
> + .get_msix_num = xhci_get_msix_num,
> #ifdef CONFIG_PM
> .pci_suspend = xhci_pci_suspend,
> .pci_resume = xhci_pci_resume,
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index c939f5f..95dc48f 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -176,210 +176,24 @@ int xhci_reset(struct xhci_hcd *xhci)
> }
>
> #ifdef CONFIG_PCI
> -static int xhci_free_msi(struct xhci_hcd *xhci)
> -{
> - int i;
> -
> - if (!xhci->msix_entries)
> - return -EINVAL;
> -
> - 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));
> - return 0;
> -}
> -
> -/*
> - * 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_dbg(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_dbg(xhci, "disable MSI interrupt\n");
> - pci_disable_msi(pdev);
> - }
> -
> - return ret;
> -}
> -
> -/*
> - * Free IRQs
> - * free all IRQs request
> - */
> -static void xhci_free_irq(struct xhci_hcd *xhci)
> -{
> - struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
> - int ret;
> -
> - /* return if using legacy interrupt */
> - if (xhci_to_hcd(xhci)->irq >= 0)
> - return;
> -
> - ret = xhci_free_msi(xhci);
> - if (!ret)
> - return;
> - if (pdev->irq >= 0)
> - free_irq(pdev->irq, xhci_to_hcd(xhci));
> -
> - return;
> -}
> -
> -/*
> - * Set up MSI-X
> - */
> -static int xhci_setup_msix(struct xhci_hcd *xhci)
> -{
> - int i, ret = 0;
> - struct usb_hcd *hcd = xhci_to_hcd(xhci);
> - struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
> -
> - /*
> - * 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;
> - }
> -
> - 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) {
> - xhci_dbg(xhci, "Failed to enable MSI-X\n");
> - goto free_entries;
> - }
> -
> - 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;
> - }
> -
> - hcd->msix_enabled = 1;
> - return ret;
> -
> -disable_msix:
> - xhci_dbg(xhci, "disable MSI-X interrupt\n");
> - xhci_free_irq(xhci);
> - pci_disable_msix(pdev);
> -free_entries:
> - kfree(xhci->msix_entries);
> - xhci->msix_entries = NULL;
> - return ret;
> -}
> -
> -/* Free any IRQs and disable MSI-X */
> -static void xhci_cleanup_msix(struct xhci_hcd *xhci)
> -{
> - struct usb_hcd *hcd = xhci_to_hcd(xhci);
> - struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
> -
> - 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);
> - }
> -
> - hcd->msix_enabled = 0;
> - return;
> -}
>
> static void xhci_msix_sync_irqs(struct xhci_hcd *xhci)
> {
> - int i;
> -
> - if (xhci->msix_entries) {
> - for (i = 0; i < xhci->msix_count; i++)
> - synchronize_irq(xhci->msix_entries[i].vector);
> - }
> + usb_hcd_msix_sync_irqs(xhci_to_hcd(xhci));
> }
>
> -static int xhci_try_enable_msi(struct usb_hcd *hcd)
> +/* called in interrupt setup during pci probe() */
> +int xhci_get_msix_num(struct usb_hcd *hcd)
> {
> struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> - struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
> - int ret;
> -
> - /*
> - * Some Fresco Logic host controllers advertise MSI, but fail to
> - * generate interrupts. Don't even try to enable MSI.
> - */
> - if (xhci->quirks & XHCI_BROKEN_MSI)
> - return 0;
> -
> - /* unregister the legacy interrupt */
> - if (hcd->irq)
> - free_irq(hcd->irq, hcd);
> - hcd->irq = -1;
>
> - ret = xhci_setup_msix(xhci);
> - if (ret)
> - /* fall back to msi*/
> - ret = xhci_setup_msi(xhci);
> -
> - if (!ret)
> - /* hcd->irq is -1, we have MSI */
> - return 0;
> -
> - if (!pdev->irq) {
> - xhci_err(xhci, "No msi-x/msi found and no IRQ in BIOS\n");
> - return -EINVAL;
> - }
> -
> - /* 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 0;
> + /* danger: xhci may be null, but it's useless in xhci_readl() now */
> + return HCS_MAX_INTRS(xhci_readl(xhci,
> + &((struct xhci_cap_regs *)hcd->regs)->hcs_params1));
> }
>
> #else
>
> -static int xhci_try_enable_msi(struct usb_hcd *hcd)
> -{
> - return 0;
> -}
> -
> -static void xhci_cleanup_msix(struct xhci_hcd *xhci)
> -{
> -}
> -
> static void xhci_msix_sync_irqs(struct xhci_hcd *xhci)
> {
> }
> @@ -411,7 +225,6 @@ int xhci_init(struct usb_hcd *hcd)
>
> return retval;
> }
> -
> /*-------------------------------------------------------------------------*/
>
>
> @@ -497,7 +310,6 @@ int xhci_run(struct usb_hcd *hcd)
> {
> u32 temp;
> u64 temp_64;
> - int ret;
> struct xhci_hcd *xhci = hcd_to_xhci(hcd);
>
> /* Start the xHCI host controller running only after the USB 2.0 roothub
> @@ -510,10 +322,6 @@ int xhci_run(struct usb_hcd *hcd)
>
> xhci_dbg(xhci, "xhci_run\n");
>
> - ret = xhci_try_enable_msi(hcd);
> - if (ret)
> - return ret;
> -
> #ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
> init_timer(&xhci->event_ring_timer);
> xhci->event_ring_timer.data = (unsigned long) xhci;
> @@ -609,7 +417,7 @@ void xhci_stop(struct usb_hcd *hcd)
> xhci_reset(xhci);
> spin_unlock_irq(&xhci->lock);
>
> - xhci_cleanup_msix(xhci);
> + usb_hcd_free_msi_msix(hcd);
>
> #ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
> /* Tell the event ring poll function not to reschedule */
> @@ -651,7 +459,7 @@ void xhci_shutdown(struct usb_hcd *hcd)
> xhci_halt(xhci);
> spin_unlock_irq(&xhci->lock);
>
> - xhci_cleanup_msix(xhci);
> + usb_hcd_free_msi_msix(hcd);
>
> xhci_dbg(xhci, "xhci_shutdown completed - status = %x\n",
> xhci_readl(xhci, &xhci->op_regs->status));
> @@ -853,7 +661,7 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
> xhci_halt(xhci);
> xhci_reset(xhci);
> spin_unlock_irq(&xhci->lock);
> - xhci_cleanup_msix(xhci);
> + usb_hcd_free_msi_msix(hcd);
>
> #ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
> /* Tell the event ring poll function not to reschedule */
> @@ -888,7 +696,11 @@ int xhci_resume(struct xhci_hcd *xhci, bool hibernated)
> if (retval)
> return retval;
> xhci_dbg(xhci, "Start the primary HCD\n");
> - retval = xhci_run(hcd->primary_hcd);
> + if (dev_is_pci(hcd->self.controller))
> + retval = usb_hcd_register_msi_msix_irqs(
> + hcd->primary_hcd);

Why not change this function to take a count of msix vectors and
pointers for data? Then you don't need the new usb_hcd driver method
for getting the msix count.

> + if (!retval)
> + retval = xhci_run(hcd->primary_hcd);
> if (!retval) {
> xhci_dbg(xhci, "Start the secondary HCD\n");
> retval = xhci_run(secondary_hcd);
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index fb99c83..8d511dd 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -1388,9 +1388,6 @@ struct xhci_hcd {
> int page_size;
> /* Valid values are 12 to 20, inclusive */
> int page_shift;
> - /* msi-x vectors */
> - int msix_count;
> - struct msix_entry *msix_entries;
> /* data structures */
> struct xhci_device_context_array *dcbaa;
> struct xhci_ring *cmd_ring;
> @@ -1643,9 +1640,11 @@ void xhci_free_command(struct xhci_hcd *xhci,
> /* xHCI PCI glue */
> int xhci_register_pci(void);
> void xhci_unregister_pci(void);
> +int xhci_get_msix_num(struct usb_hcd *hcd);
> #else
> static inline int xhci_register_pci(void) { return 0; }
> static inline void xhci_unregister_pci(void) {}
> +static inline int xhci_get_msix_num(struct usb_hcd *hcd) { return 0; }
> #endif
>
> /* xHCI host controller glue */
> diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
> index b2f62f3..5253c02 100644
> --- a/include/linux/usb/hcd.h
> +++ b/include/linux/usb/hcd.h
> @@ -22,6 +22,7 @@
> #ifdef __KERNEL__
>
> #include <linux/rwsem.h>
> +#include <linux/pci.h> /* for struct msix_entry */
>
> #define MAX_TOPO_LEVEL 6
>
> @@ -133,6 +134,12 @@ struct usb_hcd {
> u64 rsrc_len; /* memory/io resource length */
> unsigned power_budget; /* in mA, 0 = no limit */
>
> +#ifdef CONFIG_PCI
> + /* msi-x vectors */
> + int msix_count;
> + struct msix_entry *msix_entries;
> +#endif
> +
> /* bandwidth_mutex should be taken before adding or removing
> * any new bus bandwidth constraints:
> * 1. Before adding a configuration for a new device.
> @@ -205,11 +212,14 @@ struct hc_driver {
>
> /* irq handler */
> irqreturn_t (*irq) (struct usb_hcd *hcd);
> + irqreturn_t (*msi_irq) (int irq, struct usb_hcd *hcd);
> + irqreturn_t (*msix_irq) (int irq, struct usb_hcd *hcd);
>
> int flags;
> #define HCD_MEMORY 0x0001 /* HC regs use memory (else I/O) */
> #define HCD_LOCAL_MEM 0x0002 /* HC needs local memory */
> #define HCD_SHARED 0x0004 /* Two (or more) usb_hcds share HW */
> +#define HCD_MSI_FIRST 0x0008 /* Try to get MSI first, PCI only */
> #define HCD_USB11 0x0010 /* USB 1.1 */
> #define HCD_USB2 0x0020 /* USB 2.0 */
> #define HCD_USB3 0x0040 /* USB 3.0 */
> @@ -218,6 +228,7 @@ struct hc_driver {
> /* called to init HCD and root hub */
> int (*reset) (struct usb_hcd *hcd);
> int (*start) (struct usb_hcd *hcd);
> + int (*get_msix_num) (struct usb_hcd *hcd);
>
> /* NOTE: these suspend/resume calls relate to the HC as
> * a whole, not just the root hub; they're for PCI bus glue.
> @@ -393,6 +404,12 @@ extern int usb_hcd_pci_probe(struct pci_dev *dev,
> extern void usb_hcd_pci_remove(struct pci_dev *dev);
> extern void usb_hcd_pci_shutdown(struct pci_dev *dev);
>
> +extern void usb_hcd_free_msi_msix(struct usb_hcd *hcd);
> +extern void usb_hcd_msix_sync_irqs(struct usb_hcd *hcd);
> +extern int usb_hcd_request_msi_msix_irqs(struct usb_hcd *hcd,
> + unsigned int irqnum, unsigned long irqflags);
> +extern int usb_hcd_register_msi_msix_irqs(struct usb_hcd *hcd);
> +
> #ifdef CONFIG_PM_SLEEP
> extern const struct dev_pm_ops usb_hcd_pci_pm_ops;
> #endif
> --
> 1.6.3.3
>
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