[PATCH v4 2/4] xhci: Fix TRB prefetch issue of ZHAOXIN hosts

[Weitao Wang]

On some ZHAOXIN hosts, xHCI will prefetch TRB for performance
improvement. However this TRB prefetch mechanism may cross page boundary,
which may access memory not allocated by xHCI driver. In order to fix
this issue, two pages was allocated for a segment and only the first
page will be used. And add a quirk XHCI_ZHAOXIN_TRB_FETCH for this issue.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Weitao Wang <WeitaoWang-oc@xxxxxxxxxxx>
---
 drivers/usb/host/xhci-mem.c | 8 ++++++--
 drivers/usb/host/xhci-pci.c | 7 ++++++-
 drivers/usb/host/xhci.h     | 1 +
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index 7e106bd804ca..1532414c8c40 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -2352,8 +2352,12 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 	 * and our use of dma addresses in the trb_address_map radix tree needs
 	 * TRB_SEGMENT_SIZE alignment, so we pick the greater alignment need.
 	 */
-	xhci->segment_pool = dma_pool_create("xHCI ring segments", dev,
-			TRB_SEGMENT_SIZE, TRB_SEGMENT_SIZE, xhci->page_size);
+	if (xhci->quirks & XHCI_ZHAOXIN_TRB_FETCH)
+		xhci->segment_pool = dma_pool_create("xHCI ring segments", dev,
+				TRB_SEGMENT_SIZE * 2, TRB_SEGMENT_SIZE * 2, xhci->page_size * 2);
+	else
+		xhci->segment_pool = dma_pool_create("xHCI ring segments", dev,
+				TRB_SEGMENT_SIZE, TRB_SEGMENT_SIZE, xhci->page_size);
 
 	/* See Table 46 and Note on Figure 55 */
 	xhci->device_pool = dma_pool_create("xHCI input/output contexts", dev,
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 46d4d642c9bd..3dfb3e0c910b 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -528,8 +528,13 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 		xhci->quirks |= XHCI_NO_SOFT_RETRY;
 
 	if (pdev->vendor == PCI_VENDOR_ID_ZHAOXIN) {
-		if (pdev->device == 0x9202)
+		if (pdev->device == 0x9202) {
 			xhci->quirks |= XHCI_RESET_ON_RESUME;
+			xhci->quirks |= XHCI_ZHAOXIN_TRB_FETCH;
+		}
+
+		if (pdev->device == 0x9203)
+			xhci->quirks |= XHCI_ZHAOXIN_TRB_FETCH;
 	}
 
 	/* xHC spec requires PCI devices to support D3hot and D3cold */
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index 08d721921b7b..41c38bfd7348 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1905,6 +1905,7 @@ struct xhci_hcd {
 #define XHCI_EP_CTX_BROKEN_DCS	BIT_ULL(42)
 #define XHCI_SUSPEND_RESUME_CLKS	BIT_ULL(43)
 #define XHCI_RESET_TO_DEFAULT	BIT_ULL(44)
+#define XHCI_ZHAOXIN_TRB_FETCH	BIT_ULL(45)
 
 	unsigned int		num_active_eps;
 	unsigned int		limit_active_eps;
-- 
2.32.0