• Christian König's avatar
    drm/radeon: add userptr support v8 · f72a113a
    Christian König authored
    This patch adds an IOCTL for turning a pointer supplied by
    userspace into a buffer object.
    
    It imposes several restrictions upon the memory being mapped:
    
    1. It must be page aligned (both start/end addresses, i.e ptr and size).
    
    2. It must be normal system memory, not a pointer into another map of IO
    space (e.g. it must not be a GTT mmapping of another object).
    
    3. The BO is mapped into GTT, so the maximum amount of memory mapped at
    all times is still the GTT limit.
    
    4. The BO is only mapped readonly for now, so no write support.
    
    5. List of backing pages is only acquired once, so they represent a
    snapshot of the first use.
    
    Exporting and sharing as well as mapping of buffer objects created by
    this function is forbidden and results in an -EPERM.
    
    v2: squash all previous changes into first public version
    v3: fix tabs, map readonly, don't use MM callback any more
    v4: set TTM_PAGE_FLAG_SG so that TTM never messes with the pages,
        pin/unpin pages on bind/unbind instead of populate/unpopulate
    v5: rebased on 3.17-wip, IOCTL renamed to userptr, reject any unknown
        flags, better handle READONLY flag, improve permission check
    v6: fix ptr cast warning, use set_page_dirty/mark_page_accessed on unpin
    v7: add warning about it's availability in the API definition
    v8: drop access_ok check, fix VM mapping bits
    Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
    Reviewed-by: Alex Deucher <alexander.deucher@amd.com> (v4)
    Reviewed-by: Jérôme Glisse <jglisse@redhat.com> (v4)
    Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
    f72a113a
radeon_drv.c 21.4 KB