Hi Bin, Hi Nicolas,
On 20.11.20 01:31, Bin Meng wrote:
+Stefan
On Fri, Nov 20, 2020 at 1:49 AM Nicolas Saenz Julienne nsaenzjulienne@suse.de wrote:
So far we've been content with passing physical addresses when configuring memory addresses into XHCI controllers, but not all platforms have buses with transparent mappings. Specifically the Raspberry Pi 4 might introduce an offset to memory accesses incoming from its PCIe port.
Introduce xhci_virt_to_bus() and xhci_bus_to_virt() to cater with these limitations and make sure we don't break non DM users.
I believe this was already addressed by Stefan before, to support xHCI in MIPS.
I believe from taking a quick look at the code, that Nicolas not only needs to transfer between phys and virt addresses, but also needs to support different "offsets" on multiple devices. IIUTC, it's an extension to the already available support for mapped addresses (virtual != physical).
BTW: Do we really need to support non-DM code with this new approach in this late phase of DM conversion?
Thanks, Stefan
Signed-off-by: Nicolas Saenz Julienne nsaenzjulienne@suse.de
drivers/usb/host/xhci-mem.c | 45 +++++++++++++++++++----------------- drivers/usb/host/xhci-ring.c | 11 +++++---- drivers/usb/host/xhci.c | 4 ++-- include/usb/xhci.h | 22 +++++++++++++++++- 4 files changed, 54 insertions(+), 28 deletions(-)
Regards, Bin
Viele Grüße, Stefan