linux/drivers/usb/host/xhci-pci.c
Sarah Sharp 2cf95c18d5 Intel xhci: Limit number of active endpoints to 64.
The Panther Point chipset has an xHCI host controller that has a limit to
the number of active endpoints it can handle.  Ideally, it would signal
that it can't handle anymore endpoints by returning a Resource Error for
the Configure Endpoint command, but they don't.  Instead it needs software
to keep track of the number of active endpoints, across configure endpoint
commands, reset device commands, disable slot commands, and address device
commands.

Add a new endpoint context counter, xhci_hcd->num_active_eps, and use it
to track the number of endpoints the xHC has active.  This gets a little
tricky, because commands to change the number of active endpoints can
fail.  This patch adds a new xHCI quirk for these Intel hosts, and the new
code should not have any effect on other xHCI host controllers.

Fail a new device allocation if we don't have room for the new default
control endpoint.  Use the endpoint ring pointers to determine what
endpoints were active before a Reset Device command or a Disable Slot
command, and drop those once the command completes.

Fail a configure endpoint command if it would add too many new endpoints.
We have to be a bit over zealous here, and only count the number of new
endpoints to be added, without subtracting the number of dropped
endpoints.  That's because a second configure endpoint command for a
different device could sneak in before we know if the first command is
completed.  If the first command dropped resources, the host controller
fails the command for some reason, and we're nearing the limit of
endpoints, we could end up oversubscribing the host.

To fix this race condition, when evaluating whether a configure endpoint
command will fix in our bandwidth budget, only add the new endpoints to
xhci->num_active_eps, and don't subtract the dropped endpoints.  Ignore
changed endpoints (ones that are dropped and then re-added), as that
shouldn't effect the host's endpoint resources.  When the configure
endpoint command completes, subtract off the dropped endpoints.

This may mean some configuration changes may temporarily fail, but it's
always better to under-subscribe than over-subscribe resources.

(Originally my plan had been to push the resource allocation down into the
ring allocation functions.  However, that would cause us to allocate
unnecessary resources when endpoints were changed, because the xHCI driver
allocates a new ring for the changed endpoint, and only deletes the old
ring once the Configure Endpoint command succeeds.  A further complication
would have been dealing with the per-device endpoint ring cache.)

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
2011-05-27 12:08:14 -07:00

369 lines
10 KiB
C

/*
* xHCI host controller driver PCI Bus Glue.
*
* Copyright (C) 2008 Intel Corp.
*
* Author: Sarah Sharp
* Some code borrowed from the Linux EHCI driver.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/pci.h>
#include <linux/slab.h>
#include "xhci.h"
/* Device for a quirk */
#define PCI_VENDOR_ID_FRESCO_LOGIC 0x1b73
#define PCI_DEVICE_ID_FRESCO_LOGIC_PDK 0x1000
static const char hcd_name[] = "xhci_hcd";
/* called after powerup, by probe or system-pm "wakeup" */
static int xhci_pci_reinit(struct xhci_hcd *xhci, struct pci_dev *pdev)
{
/*
* TODO: Implement finding debug ports later.
* TODO: see if there are any quirks that need to be added to handle
* new extended capabilities.
*/
/* PCI Memory-Write-Invalidate cycle support is optional (uncommon) */
if (!pci_set_mwi(pdev))
xhci_dbg(xhci, "MWI active\n");
xhci_dbg(xhci, "Finished xhci_pci_reinit\n");
return 0;
}
/* called during probe() after chip reset completes */
static int xhci_pci_setup(struct usb_hcd *hcd)
{
struct xhci_hcd *xhci;
struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
int retval;
u32 temp;
hcd->self.sg_tablesize = TRBS_PER_SEGMENT - 2;
if (usb_hcd_is_primary_hcd(hcd)) {
xhci = kzalloc(sizeof(struct xhci_hcd), GFP_KERNEL);
if (!xhci)
return -ENOMEM;
*((struct xhci_hcd **) hcd->hcd_priv) = xhci;
xhci->main_hcd = hcd;
/* Mark the first roothub as being USB 2.0.
* The xHCI driver will register the USB 3.0 roothub.
*/
hcd->speed = HCD_USB2;
hcd->self.root_hub->speed = USB_SPEED_HIGH;
/*
* USB 2.0 roothub under xHCI has an integrated TT,
* (rate matching hub) as opposed to having an OHCI/UHCI
* companion controller.
*/
hcd->has_tt = 1;
} else {
/* xHCI private pointer was set in xhci_pci_probe for the second
* registered roothub.
*/
xhci = hcd_to_xhci(hcd);
temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
if (HCC_64BIT_ADDR(temp)) {
xhci_dbg(xhci, "Enabling 64-bit DMA addresses.\n");
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(64));
} else {
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(32));
}
return 0;
}
xhci->cap_regs = hcd->regs;
xhci->op_regs = hcd->regs +
HC_LENGTH(xhci_readl(xhci, &xhci->cap_regs->hc_capbase));
xhci->run_regs = hcd->regs +
(xhci_readl(xhci, &xhci->cap_regs->run_regs_off) & RTSOFF_MASK);
/* Cache read-only capability registers */
xhci->hcs_params1 = xhci_readl(xhci, &xhci->cap_regs->hcs_params1);
xhci->hcs_params2 = xhci_readl(xhci, &xhci->cap_regs->hcs_params2);
xhci->hcs_params3 = xhci_readl(xhci, &xhci->cap_regs->hcs_params3);
xhci->hcc_params = xhci_readl(xhci, &xhci->cap_regs->hc_capbase);
xhci->hci_version = HC_VERSION(xhci->hcc_params);
xhci->hcc_params = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
xhci_print_registers(xhci);
/* Look for vendor-specific quirks */
if (pdev->vendor == PCI_VENDOR_ID_FRESCO_LOGIC &&
pdev->device == PCI_DEVICE_ID_FRESCO_LOGIC_PDK &&
pdev->revision == 0x0) {
xhci->quirks |= XHCI_RESET_EP_QUIRK;
xhci_dbg(xhci, "QUIRK: Fresco Logic xHC needs configure"
" endpoint cmd after reset endpoint\n");
}
if (pdev->vendor == PCI_VENDOR_ID_NEC)
xhci->quirks |= XHCI_NEC_HOST;
/* AMD PLL quirk */
if (pdev->vendor == PCI_VENDOR_ID_AMD && usb_amd_find_chipset_info())
xhci->quirks |= XHCI_AMD_PLL_FIX;
if (pdev->vendor == PCI_VENDOR_ID_INTEL &&
pdev->device == PCI_DEVICE_ID_INTEL_PANTHERPOINT_XHCI) {
xhci->quirks |= XHCI_SPURIOUS_SUCCESS;
xhci->quirks |= XHCI_EP_LIMIT_QUIRK;
xhci->limit_active_eps = 64;
}
/* Make sure the HC is halted. */
retval = xhci_halt(xhci);
if (retval)
goto error;
xhci_dbg(xhci, "Resetting HCD\n");
/* Reset the internal HC memory state and registers. */
retval = xhci_reset(xhci);
if (retval)
goto error;
xhci_dbg(xhci, "Reset complete\n");
temp = xhci_readl(xhci, &xhci->cap_regs->hcc_params);
if (HCC_64BIT_ADDR(temp)) {
xhci_dbg(xhci, "Enabling 64-bit DMA addresses.\n");
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(64));
} else {
dma_set_mask(hcd->self.controller, DMA_BIT_MASK(32));
}
xhci_dbg(xhci, "Calling HCD init\n");
/* Initialize HCD and host controller data structures. */
retval = xhci_init(hcd);
if (retval)
goto error;
xhci_dbg(xhci, "Called HCD init\n");
pci_read_config_byte(pdev, XHCI_SBRN_OFFSET, &xhci->sbrn);
xhci_dbg(xhci, "Got SBRN %u\n", (unsigned int) xhci->sbrn);
/* Find any debug ports */
retval = xhci_pci_reinit(xhci, pdev);
if (!retval)
return retval;
error:
kfree(xhci);
return retval;
}
/*
* 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.
*/
static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
{
int retval;
struct xhci_hcd *xhci;
struct hc_driver *driver;
struct usb_hcd *hcd;
driver = (struct hc_driver *)id->driver_data;
/* 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
* to say USB 2.0, but I'm not sure what the implications would be in
* the other parts of the HCD code.
*/
retval = usb_hcd_pci_probe(dev, id);
if (retval)
return retval;
/* USB 2.0 roothub is stored in the PCI device now. */
hcd = dev_get_drvdata(&dev->dev);
xhci = hcd_to_xhci(hcd);
xhci->shared_hcd = usb_create_shared_hcd(driver, &dev->dev,
pci_name(dev), hcd);
if (!xhci->shared_hcd) {
retval = -ENOMEM;
goto dealloc_usb2_hcd;
}
/* Set the xHCI pointer before xhci_pci_setup() (aka hcd_driver.reset)
* is called by usb_add_hcd().
*/
*((struct xhci_hcd **) xhci->shared_hcd->hcd_priv) = xhci;
retval = usb_add_hcd(xhci->shared_hcd, dev->irq,
IRQF_DISABLED | IRQF_SHARED);
if (retval)
goto put_usb3_hcd;
/* Roothub already marked as USB 3.0 speed */
return 0;
put_usb3_hcd:
usb_put_hcd(xhci->shared_hcd);
dealloc_usb2_hcd:
usb_hcd_pci_remove(dev);
return retval;
}
static void xhci_pci_remove(struct pci_dev *dev)
{
struct xhci_hcd *xhci;
xhci = hcd_to_xhci(pci_get_drvdata(dev));
if (xhci->shared_hcd) {
usb_remove_hcd(xhci->shared_hcd);
usb_put_hcd(xhci->shared_hcd);
}
usb_hcd_pci_remove(dev);
kfree(xhci);
}
#ifdef CONFIG_PM
static int xhci_pci_suspend(struct usb_hcd *hcd, bool do_wakeup)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
int retval = 0;
if (hcd->state != HC_STATE_SUSPENDED ||
xhci->shared_hcd->state != HC_STATE_SUSPENDED)
return -EINVAL;
retval = xhci_suspend(xhci);
return retval;
}
static int xhci_pci_resume(struct usb_hcd *hcd, bool hibernated)
{
struct xhci_hcd *xhci = hcd_to_xhci(hcd);
struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
int retval = 0;
/* The BIOS on systems with the Intel Panther Point chipset may or may
* not support xHCI natively. That means that during system resume, it
* may switch the ports back to EHCI so that users can use their
* keyboard to select a kernel from GRUB after resume from hibernate.
*
* The BIOS is supposed to remember whether the OS had xHCI ports
* enabled before resume, and switch the ports back to xHCI when the
* BIOS/OS semaphore is written, but we all know we can't trust BIOS
* writers.
*
* Unconditionally switch the ports back to xHCI after a system resume.
* We can't tell whether the EHCI or xHCI controller will be resumed
* first, so we have to do the port switchover in both drivers. Writing
* a '1' to the port switchover registers should have no effect if the
* port was already switched over.
*/
if (usb_is_intel_switchable_xhci(pdev))
usb_enable_xhci_ports(pdev);
retval = xhci_resume(xhci, hibernated);
return retval;
}
#endif /* CONFIG_PM */
static const struct hc_driver xhci_pci_hc_driver = {
.description = hcd_name,
.product_desc = "xHCI Host Controller",
.hcd_priv_size = sizeof(struct xhci_hcd *),
/*
* generic hardware linkage
*/
.irq = xhci_irq,
.flags = HCD_MEMORY | HCD_USB3 | HCD_SHARED,
/*
* basic lifecycle operations
*/
.reset = xhci_pci_setup,
.start = xhci_run,
#ifdef CONFIG_PM
.pci_suspend = xhci_pci_suspend,
.pci_resume = xhci_pci_resume,
#endif
.stop = xhci_stop,
.shutdown = xhci_shutdown,
/*
* managing i/o requests and associated device resources
*/
.urb_enqueue = xhci_urb_enqueue,
.urb_dequeue = xhci_urb_dequeue,
.alloc_dev = xhci_alloc_dev,
.free_dev = xhci_free_dev,
.alloc_streams = xhci_alloc_streams,
.free_streams = xhci_free_streams,
.add_endpoint = xhci_add_endpoint,
.drop_endpoint = xhci_drop_endpoint,
.endpoint_reset = xhci_endpoint_reset,
.check_bandwidth = xhci_check_bandwidth,
.reset_bandwidth = xhci_reset_bandwidth,
.address_device = xhci_address_device,
.update_hub_device = xhci_update_hub_device,
.reset_device = xhci_discover_or_reset_device,
/*
* scheduling support
*/
.get_frame_number = xhci_get_frame,
/* Root hub support */
.hub_control = xhci_hub_control,
.hub_status_data = xhci_hub_status_data,
.bus_suspend = xhci_bus_suspend,
.bus_resume = xhci_bus_resume,
};
/*-------------------------------------------------------------------------*/
/* PCI driver selection metadata; PCI hotplugging uses this */
static const struct pci_device_id pci_ids[] = { {
/* handle any USB 3.0 xHCI controller */
PCI_DEVICE_CLASS(PCI_CLASS_SERIAL_USB_XHCI, ~0),
.driver_data = (unsigned long) &xhci_pci_hc_driver,
},
{ /* end: all zeroes */ }
};
MODULE_DEVICE_TABLE(pci, pci_ids);
/* pci driver glue; this is a "new style" PCI driver module */
static struct pci_driver xhci_pci_driver = {
.name = (char *) hcd_name,
.id_table = pci_ids,
.probe = xhci_pci_probe,
.remove = xhci_pci_remove,
/* suspend and resume implemented later */
.shutdown = usb_hcd_pci_shutdown,
#ifdef CONFIG_PM_SLEEP
.driver = {
.pm = &usb_hcd_pci_pm_ops
},
#endif
};
int xhci_register_pci(void)
{
return pci_register_driver(&xhci_pci_driver);
}
void xhci_unregister_pci(void)
{
pci_unregister_driver(&xhci_pci_driver);
}