From ecaa4902439298f6b0e29f47424a86b310a9ff4f Mon Sep 17 00:00:00 2001
From: D Scott Phillips <scott@os.amperecomputing.com>
Date: Thu, 30 Mar 2023 17:30:54 +0300
Subject: [PATCH] xhci: also avoid the XHCI_ZERO_64B_REGS quirk with a
passthrough iommu
Git-commit: ecaa4902439298f6b0e29f47424a86b310a9ff4f
References: git-fixes
Patch-mainline: v6.3-rc6
Previously the quirk was skipped when no iommu was present. The same
rationale for skipping the quirk also applies in the iommu.passthrough=1
case.
Skip applying the XHCI_ZERO_64B_REGS quirk if the device's iommu domain is
passthrough.
Fixes: 12de0a35c996 ("xhci: Add quirk to zero 64bit registers on Renesas PCIe controllers")
Cc: stable <stable@kernel.org>
Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20230330143056.1390020-2-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/usb/host/xhci.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -21,6 +21,7 @@
*/
#include <linux/pci.h>
+#include <linux/iommu.h>
#include <linux/iopoll.h>
#include <linux/irq.h>
#include <linux/log2.h>
@@ -237,6 +238,7 @@ int xhci_reset(struct xhci_hcd *xhci)
static void xhci_zero_64b_regs(struct xhci_hcd *xhci)
{
struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+ struct iommu_domain *domain;
int err, i;
u64 val;
@@ -254,7 +256,9 @@ static void xhci_zero_64b_regs(struct xh
* an iommu. Doing anything when there is no iommu is definitely
* unsafe...
*/
- if (!(xhci->quirks & XHCI_ZERO_64B_REGS) || !dev->iommu_group)
+ domain = iommu_get_domain_for_dev(dev);
+ if (!(xhci->quirks & XHCI_ZERO_64B_REGS) || !dev->iommu_group ||
+ domain->type == IOMMU_DOMAIN_IDENTITY)
return;
xhci_info(xhci, "Zeroing 64bit base registers, expecting fault\n");