Changes in V3: 1. Change the device page allocation method of the Intel mic layer in Patch 1 to align with the vring allocation. 2. Move the vring physical address changes in mmap callback from Prach 3 to 1. 3. Use must_be_zero instead of directly deleting used_address_updated in Patch 2 to avoid the influence of ABI change. (I tried to use dma_mmap_coherent api in Patch 4 as Christoph suggested, but met some issues explained here https://lore.kernel.org/patchwork/patch/1313327/, so there is no change to Patch 4, and still can't find a better way than patch 3) The original vop driver only supports dma coherent device, as it allocates and maps vring by _get_free_pages and dma_map_single, but not use dma_sync_single_for_cpu/device to sync the updates of device_page/vring between EP and RC, which will cause memory synchronization problem for device don't support hardware dma coherent. And allocate vrings use dma_alloc_coherent is a common way in kernel, as the memory interacted between two systems should use consistent memory to avoid caching effects. So here add noncoherent platform support for vop driver. Also add some related dma changes to make sure noncoherent platform works well. Sherry Sun (4): misc: vop: change the way of allocating vring and device page misc: vop: do not allocate and reassign the used ring misc: vop: simply return the saved dma address instead of virt_to_phys misc: vop: mapping kernel memory to user space as noncached drivers/misc/mic/bus/vop_bus.h | 2 + drivers/misc/mic/host/mic_boot.c | 8 +++ drivers/misc/mic/host/mic_main.c | 15 ++---- drivers/misc/mic/vop/vop_debugfs.c | 2 - drivers/misc/mic/vop/vop_main.c | 48 +++-------------- drivers/misc/mic/vop/vop_vringh.c | 84 +++++++----------------------- include/uapi/linux/mic_common.h | 5 +- 7 files changed, 42 insertions(+), 122 deletions(-) -- 2.17.1
