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linux-pinenote/drivers/usb/host/ohci-exynos.c
Stephen Warren 3b9561e9d9 USB: set device dma_mask without reference to global data 
Many USB host drivers contain code such as:

if (!pdev->dev.dma_mask)
        pdev->dev.dma_mask = &tegra_ehci_dma_mask;

... where tegra_ehci_dma_mask is a global. I suspect this code originated
in commit 4a53f4e "USB: ehci-tegra: add probing through device tree" and
was simply copied everywhere else.

This works fine when the code is built-in, but can cause a crash when the
code is in a module. The first module load sets up the dma_mask pointer,
but if the module is removed and re-inserted, the value is now non-NULL,
and hence is not updated to point at the new location, and hence points
at a stale location within the previous module load address, which in
turn causes a crash if the pointer is de-referenced.

The simplest way of solving this seems to be to copy the code from
ehci-platform.c, which uses the coherent_dma_mask as the target for the
dma_mask pointer.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-05-16 17:30:52 -07:00

336 lines
7.9 KiB
C
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/*
* SAMSUNG EXYNOS USB HOST OHCI Controller
*
* Copyright (C) 2011 Samsung Electronics Co.Ltd
* Author: Jingoo Han <jg1.han@samsung.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*/
#include <linux/clk.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/platform_data/usb-ohci-exynos.h>
#include <linux/usb/phy.h>
#include <linux/usb/samsung_usb_phy.h>
struct exynos_ohci_hcd {
struct device *dev;
struct usb_hcd *hcd;
struct clk *clk;
struct usb_phy *phy;
struct usb_otg *otg;
struct exynos4_ohci_platdata *pdata;
};
static void exynos_ohci_phy_enable(struct exynos_ohci_hcd *exynos_ohci)
{
struct platform_device *pdev = to_platform_device(exynos_ohci->dev);
if (exynos_ohci->phy)
usb_phy_init(exynos_ohci->phy);
else if (exynos_ohci->pdata && exynos_ohci->pdata->phy_init)
exynos_ohci->pdata->phy_init(pdev, USB_PHY_TYPE_HOST);
}
static void exynos_ohci_phy_disable(struct exynos_ohci_hcd *exynos_ohci)
{
struct platform_device *pdev = to_platform_device(exynos_ohci->dev);
if (exynos_ohci->phy)
usb_phy_shutdown(exynos_ohci->phy);
else if (exynos_ohci->pdata && exynos_ohci->pdata->phy_exit)
exynos_ohci->pdata->phy_exit(pdev, USB_PHY_TYPE_HOST);
}
static int ohci_exynos_reset(struct usb_hcd *hcd)
{
return ohci_init(hcd_to_ohci(hcd));
}
static int ohci_exynos_start(struct usb_hcd *hcd)
{
struct ohci_hcd *ohci = hcd_to_ohci(hcd);
int ret;
ohci_dbg(ohci, "ohci_exynos_start, ohci:%p", ohci);
ret = ohci_run(ohci);
if (ret < 0) {
dev_err(hcd->self.controller, "can't start %s\n",
hcd->self.bus_name);
ohci_stop(hcd);
return ret;
}
return 0;
}
static const struct hc_driver exynos_ohci_hc_driver = {
.description = hcd_name,
.product_desc = "EXYNOS OHCI Host Controller",
.hcd_priv_size = sizeof(struct ohci_hcd),
.irq = ohci_irq,
.flags = HCD_MEMORY|HCD_USB11,
.reset = ohci_exynos_reset,
.start = ohci_exynos_start,
.stop = ohci_stop,
.shutdown = ohci_shutdown,
.get_frame_number = ohci_get_frame,
.urb_enqueue = ohci_urb_enqueue,
.urb_dequeue = ohci_urb_dequeue,
.endpoint_disable = ohci_endpoint_disable,
.hub_status_data = ohci_hub_status_data,
.hub_control = ohci_hub_control,
#ifdef CONFIG_PM
.bus_suspend = ohci_bus_suspend,
.bus_resume = ohci_bus_resume,
#endif
.start_port_reset = ohci_start_port_reset,
};
static int exynos_ohci_probe(struct platform_device *pdev)
{
struct exynos4_ohci_platdata *pdata = pdev->dev.platform_data;
struct exynos_ohci_hcd *exynos_ohci;
struct usb_hcd *hcd;
struct ohci_hcd *ohci;
struct resource *res;
struct usb_phy *phy;
int irq;
int err;
/*
* Right now device-tree probed devices don't get dma_mask set.
* Since shared usb code relies on it, set it here for now.
* Once we move to full device tree support this will vanish off.
*/
if (!pdev->dev.dma_mask)
pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
if (!pdev->dev.coherent_dma_mask)
pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
exynos_ohci = devm_kzalloc(&pdev->dev, sizeof(struct exynos_ohci_hcd),
GFP_KERNEL);
if (!exynos_ohci)
return -ENOMEM;
if (of_device_is_compatible(pdev->dev.of_node,
"samsung,exynos5440-ohci"))
goto skip_phy;
phy = devm_usb_get_phy(&pdev->dev, USB_PHY_TYPE_USB2);
if (IS_ERR(phy)) {
/* Fallback to pdata */
if (!pdata) {
dev_warn(&pdev->dev, "no platform data or transceiver defined\n");
return -EPROBE_DEFER;
} else {
exynos_ohci->pdata = pdata;
}
} else {
exynos_ohci->phy = phy;
exynos_ohci->otg = phy->otg;
}
skip_phy:
exynos_ohci->dev = &pdev->dev;
hcd = usb_create_hcd(&exynos_ohci_hc_driver, &pdev->dev,
dev_name(&pdev->dev));
if (!hcd) {
dev_err(&pdev->dev, "Unable to create HCD\n");
return -ENOMEM;
}
exynos_ohci->hcd = hcd;
exynos_ohci->clk = devm_clk_get(&pdev->dev, "usbhost");
if (IS_ERR(exynos_ohci->clk)) {
dev_err(&pdev->dev, "Failed to get usbhost clock\n");
err = PTR_ERR(exynos_ohci->clk);
goto fail_clk;
}
err = clk_prepare_enable(exynos_ohci->clk);
if (err)
goto fail_clk;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "Failed to get I/O memory\n");
err = -ENXIO;
goto fail_io;
}
hcd->rsrc_start = res->start;
hcd->rsrc_len = resource_size(res);
hcd->regs = devm_ioremap(&pdev->dev, res->start, hcd->rsrc_len);
if (!hcd->regs) {
dev_err(&pdev->dev, "Failed to remap I/O memory\n");
err = -ENOMEM;
goto fail_io;
}
irq = platform_get_irq(pdev, 0);
if (!irq) {
dev_err(&pdev->dev, "Failed to get IRQ\n");
err = -ENODEV;
goto fail_io;
}
if (exynos_ohci->otg)
exynos_ohci->otg->set_host(exynos_ohci->otg,
&exynos_ohci->hcd->self);
exynos_ohci_phy_enable(exynos_ohci);
ohci = hcd_to_ohci(hcd);
ohci_hcd_init(ohci);
err = usb_add_hcd(hcd, irq, IRQF_SHARED);
if (err) {
dev_err(&pdev->dev, "Failed to add USB HCD\n");
goto fail_add_hcd;
}
platform_set_drvdata(pdev, exynos_ohci);
return 0;
fail_add_hcd:
exynos_ohci_phy_disable(exynos_ohci);
fail_io:
clk_disable_unprepare(exynos_ohci->clk);
fail_clk:
usb_put_hcd(hcd);
return err;
}
static int exynos_ohci_remove(struct platform_device *pdev)
{
struct exynos_ohci_hcd *exynos_ohci = platform_get_drvdata(pdev);
struct usb_hcd *hcd = exynos_ohci->hcd;
usb_remove_hcd(hcd);
if (exynos_ohci->otg)
exynos_ohci->otg->set_host(exynos_ohci->otg,
&exynos_ohci->hcd->self);
exynos_ohci_phy_disable(exynos_ohci);
clk_disable_unprepare(exynos_ohci->clk);
usb_put_hcd(hcd);
return 0;
}
static void exynos_ohci_shutdown(struct platform_device *pdev)
{
struct exynos_ohci_hcd *exynos_ohci = platform_get_drvdata(pdev);
struct usb_hcd *hcd = exynos_ohci->hcd;
if (hcd->driver->shutdown)
hcd->driver->shutdown(hcd);
}
#ifdef CONFIG_PM
static int exynos_ohci_suspend(struct device *dev)
{
struct exynos_ohci_hcd *exynos_ohci = dev_get_drvdata(dev);
struct usb_hcd *hcd = exynos_ohci->hcd;
struct ohci_hcd *ohci = hcd_to_ohci(hcd);
unsigned long flags;
int rc = 0;
/*
* Root hub was already suspended. Disable irq emission and
* mark HW unaccessible, bail out if RH has been resumed. Use
* the spinlock to properly synchronize with possible pending
* RH suspend or resume activity.
*/
spin_lock_irqsave(&ohci->lock, flags);
if (ohci->rh_state != OHCI_RH_SUSPENDED &&
ohci->rh_state != OHCI_RH_HALTED) {
rc = -EINVAL;
goto fail;
}
clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
if (exynos_ohci->otg)
exynos_ohci->otg->set_host(exynos_ohci->otg,
&exynos_ohci->hcd->self);
exynos_ohci_phy_disable(exynos_ohci);
clk_disable_unprepare(exynos_ohci->clk);
fail:
spin_unlock_irqrestore(&ohci->lock, flags);
return rc;
}
static int exynos_ohci_resume(struct device *dev)
{
struct exynos_ohci_hcd *exynos_ohci = dev_get_drvdata(dev);
struct usb_hcd *hcd = exynos_ohci->hcd;
clk_prepare_enable(exynos_ohci->clk);
if (exynos_ohci->otg)
exynos_ohci->otg->set_host(exynos_ohci->otg,
&exynos_ohci->hcd->self);
exynos_ohci_phy_enable(exynos_ohci);
ohci_resume(hcd, false);
return 0;
}
#else
#define exynos_ohci_suspend NULL
#define exynos_ohci_resume NULL
#endif
static const struct dev_pm_ops exynos_ohci_pm_ops = {
.suspend = exynos_ohci_suspend,
.resume = exynos_ohci_resume,
};
#ifdef CONFIG_OF
static const struct of_device_id exynos_ohci_match[] = {
{ .compatible = "samsung,exynos4210-ohci" },
{ .compatible = "samsung,exynos5440-ohci" },
{},
};
MODULE_DEVICE_TABLE(of, exynos_ohci_match);
#endif
static struct platform_driver exynos_ohci_driver = {
.probe = exynos_ohci_probe,
.remove = exynos_ohci_remove,
.shutdown = exynos_ohci_shutdown,
.driver = {
.name = "exynos-ohci",
.owner = THIS_MODULE,
.pm = &exynos_ohci_pm_ops,
.of_match_table = of_match_ptr(exynos_ohci_match),
}
};
MODULE_ALIAS("platform:exynos-ohci");
MODULE_AUTHOR("Jingoo Han <jg1.han@samsung.com>");
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