[PATCH 4/4] xhci: Preserve RsvdP bits in ERSTBA register correctly

[Mathias Nyman <mathias.nyman@linux.intel.com>]

From: Lukas Wunner <lukas@wunner.de>

xhci_add_interrupter() erroneously preserves only the lowest 4 bits when
writing the ERSTBA register, not the lowest 6 bits.  Fix it.

Migrate the ERST_BASE_RSVDP macro to the modern GENMASK_ULL() syntax to
avoid a u64 cast.

This was previously fixed by commit 8c1cbec9db1a ("xhci: fix event ring
segment table related masks and variables in header"), but immediately
undone by commit b17a57f89f69 ("xhci: Refactor interrupter code for
initial multi interrupter support.").

Fixes: b17a57f89f69 ("xhci: Refactor interrupter code for initial multi interrupter support.")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v6.3+
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci-mem.c | 4 ++--
 drivers/usb/host/xhci.h     | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 8714ab5bf04d..0a37f0d511cf 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2285,8 +2285,8 @@ xhci_add_interrupter(struct xhci_hcd *xhci, struct xhci_interrupter *ir,
 	writel(erst_size, &ir->ir_set->erst_size);
 
 	erst_base = xhci_read_64(xhci, &ir->ir_set->erst_base);
-	erst_base &= ERST_PTR_MASK;
-	erst_base |= (ir->erst.erst_dma_addr & (u64) ~ERST_PTR_MASK);
+	erst_base &= ERST_BASE_RSVDP;
+	erst_base |= ir->erst.erst_dma_addr & ~ERST_BASE_RSVDP;
 	xhci_write_64(xhci, erst_base, &ir->ir_set->erst_base);
 
 	/* Set the event ring dequeue address of this interrupter */
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 7e282b4522c0..5df370482521 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -514,7 +514,7 @@ struct xhci_intr_reg {
 #define	ERST_SIZE_MASK		(0xffff << 16)
 
 /* erst_base bitmasks */
-#define ERST_BASE_RSVDP		(0x3f)
+#define ERST_BASE_RSVDP		(GENMASK_ULL(5, 0))
 
 /* erst_dequeue bitmasks */
 /* Dequeue ERST Segment Index (DESI) - Segment number (or alias)
-- 
2.25.1