[PATCH 5.15 152/201] xhci: dbc: refactor xhci_dbc_init()

Greg Kroah-Hartman
2022-07-27T17:20:14Z

From: Mathias Nyman <mathias.nyman@linux.intel.com>

[ Upstream commit 534675942e901959b5d8dc11ea526c4e48817d8e ]

Refactor xhci_dbc_init(), splitting it into logical
parts closer to the Linux device model.

- Create the fake dbc device, depends on xhci strucure
- Allocate a dbc structure, xhci agnostic
- Call xhci_dbc_tty_probe(), similar to actual probe.

Adjustments to xhci_dbc_exit and xhci_dbc_remove are also needed
as a result to the xhci_dbc_init() changes

Mostly non-functional changes, except for creating the dbc sysfs
entry earlier, together with the dbc structure.

Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220216095153.1303105-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/host/xhci-dbgcap.c | 124 ++++++++++++++++++---------------
1 file changed, 66 insertions(+), 58 deletions(-)

diff --git a/drivers/usb/host/xhci-dbgcap.c b/drivers/usb/host/xhci-dbgcap.c
index ccb0156fcebe..6a437862b498 100644
--- a/drivers/usb/host/xhci-dbgcap.c
+++ b/drivers/usb/host/xhci-dbgcap.c
@@ -924,49 +924,6 @@ static void xhci_do_dbc_exit(struct xhci_hcd *xhci)
spin_unlock_irqrestore(&xhci->lock, flags);
}

-static int xhci_do_dbc_init(struct xhci_hcd *xhci)
-{
- u32 reg;
- struct xhci_dbc *dbc;
- unsigned long flags;
- void __iomem *base;
- int dbc_cap_offs;
-
- base = &xhci->cap_regs->hc_capbase;
- dbc_cap_offs = xhci_find_next_ext_cap(base, 0, XHCI_EXT_CAPS_DEBUG);
- if (!dbc_cap_offs)
- return -ENODEV;
-
- dbc = kzalloc(sizeof(*dbc), GFP_KERNEL);
- if (!dbc)
- return -ENOMEM;
-
- dbc->regs = base + dbc_cap_offs;
-
- /* We will avoid using DbC in xhci driver if it's in use. */
- reg = readl(&dbc->regs->control);
- if (reg & DBC_CTRL_DBC_ENABLE) {
- kfree(dbc);
- return -EBUSY;
- }
-
- spin_lock_irqsave(&xhci->lock, flags);
- if (xhci->dbc) {
- spin_unlock_irqrestore(&xhci->lock, flags);
- kfree(dbc);
- return -EBUSY;
- }
- xhci->dbc = dbc;
- spin_unlock_irqrestore(&xhci->lock, flags);
-
- dbc->xhci = xhci;
- dbc->dev = xhci_to_hcd(xhci)->self.sysdev;
- INIT_DELAYED_WORK(&dbc->event_work, xhci_dbc_handle_events);
- spin_lock_init(&dbc->lock);
-
- return 0;
-}
-
static ssize_t dbc_show(struct device *dev,
struct device_attribute *attr,
char *buf)
@@ -1026,44 +983,95 @@ static ssize_t dbc_store(struct device *dev,

static DEVICE_ATTR_RW(dbc);

-int xhci_dbc_init(struct xhci_hcd *xhci)
+struct xhci_dbc *
+xhci_alloc_dbc(struct device *dev, void __iomem *base)
{
+ struct xhci_dbc *dbc;
int ret;
- struct device *dev = xhci_to_hcd(xhci)->self.controller;

- ret = xhci_do_dbc_init(xhci);
+ dbc = kzalloc(sizeof(*dbc), GFP_KERNEL);
+ if (!dbc)
+ return NULL;
+
+ dbc->regs = base;
+ dbc->dev = dev;
+
+ if (readl(&dbc->regs->control) & DBC_CTRL_DBC_ENABLE)
+ return NULL;
+
+ INIT_DELAYED_WORK(&dbc->event_work, xhci_dbc_handle_events);
+ spin_lock_init(&dbc->lock);
+
+ ret = device_create_file(dev, &dev_attr_dbc);
if (ret)
- goto init_err3;
+ goto err;
+
+ return dbc;
+err:
+ kfree(dbc);
+ return NULL;
+}
+
+/* undo what xhci_alloc_dbc() did */
+void xhci_dbc_remove(struct xhci_dbc *dbc)
+{
+ if (!dbc)
+ return;
+ /* stop hw, stop wq and call dbc->ops->stop() */
+ xhci_dbc_stop(dbc);
+
+ /* remove sysfs files */
+ device_remove_file(dbc->dev, &dev_attr_dbc);
+
+ kfree(dbc);
+}
+
+int xhci_dbc_init(struct xhci_hcd *xhci)
+{
+ struct device *dev;
+ void __iomem *base;
+ int ret;
+ int dbc_cap_offs;
+
+ /* create all parameters needed resembling a dbc device */
+ dev = xhci_to_hcd(xhci)->self.controller;
+ base = &xhci->cap_regs->hc_capbase;
+
+ dbc_cap_offs = xhci_find_next_ext_cap(base, 0, XHCI_EXT_CAPS_DEBUG);
+ if (!dbc_cap_offs)
+ return -ENODEV;
+
+ /* already allocated and in use */
+ if (xhci->dbc)
+ return -EBUSY;
+
+ xhci->dbc = xhci_alloc_dbc(dev, base);
+ if (!xhci->dbc)
+ return -ENOMEM;

ret = xhci_dbc_tty_probe(xhci);
if (ret)
goto init_err2;

- ret = device_create_file(dev, &dev_attr_dbc);
- if (ret)
- goto init_err1;
-
return 0;

-init_err1:
- xhci_dbc_tty_remove(xhci->dbc);
init_err2:
xhci_do_dbc_exit(xhci);
-init_err3:
return ret;
}

void xhci_dbc_exit(struct xhci_hcd *xhci)
{
- struct device *dev = xhci_to_hcd(xhci)->self.controller;
+ unsigned long flags;

if (!xhci->dbc)
return;

- device_remove_file(dev, &dev_attr_dbc);
xhci_dbc_tty_remove(xhci->dbc);
- xhci_dbc_stop(xhci->dbc);
- xhci_do_dbc_exit(xhci);
+ xhci_dbc_remove(xhci->dbc);
+ spin_lock_irqsave(&xhci->lock, flags);
+ xhci->dbc = NULL;
+ spin_unlock_irqrestore(&xhci->lock, flags);
}

#ifdef CONFIG_PM
--
2.35.1