Re: [PATCH 3/3] usb: xhci: Notify xen when DbC is unsafe to use
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-05-12 07:03:19
Also in:
lkml, xen-devel
On Tue, May 11, 2021 at 06:18:21PM -0600, Connor Davis wrote:
quoted hunk ↗ jump to hunk
When running as a dom0 guest on Xen, check if the USB3 debug capability is enabled before xHCI reset, suspend, and resume. If it is, call xen_dbgp_reset_prep() to notify Xen that it is unsafe to touch MMIO registers until the next xen_dbgp_external_startup(). This notification allows Xen to avoid undefined behavior resulting from MMIO access when the host controller's CNR bit is set or when the device transitions to D3hot. Signed-off-by: Connor Davis <redacted> --- drivers/usb/host/xhci-dbgcap.h | 6 ++++ drivers/usb/host/xhci.c | 57 ++++++++++++++++++++++++++++++++++ drivers/usb/host/xhci.h | 1 + 3 files changed, 64 insertions(+)diff --git a/drivers/usb/host/xhci-dbgcap.h b/drivers/usb/host/xhci-dbgcap.h index c70b78d504eb..24784b82a840 100644 --- a/drivers/usb/host/xhci-dbgcap.h +++ b/drivers/usb/host/xhci-dbgcap.h@@ -227,4 +227,10 @@ static inline int xhci_dbc_resume(struct xhci_hcd *xhci) return 0; } #endif /* CONFIG_USB_XHCI_DBGCAP */ + +#ifdef CONFIG_XEN_DOM0 +int xen_dbgp_reset_prep(struct usb_hcd *hcd); +int xen_dbgp_external_startup(struct usb_hcd *hcd); +#endif /* CONFIG_XEN_DOM0 */ + #endif /* __LINUX_XHCI_DBGCAP_H */diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index ca9385d22f68..afe44169183f 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c@@ -37,6 +37,57 @@ static unsigned long long quirks; module_param(quirks, ullong, S_IRUGO); MODULE_PARM_DESC(quirks, "Bit flags for quirks to be enabled as default"); +#ifdef CONFIG_XEN_DOM0 +#include <xen/xen.h>
<snip> Can't this #ifdef stuff go into a .h file? thanks, greg k-h