Re: [Intel-gfx] [PATCH i-g-t v3 03/11] lib/i915/gem_mman: add fixed mode to gem_mmap_offset__cpu

Dixit, Ashutosh
2021-08-02T06:30:04Z

On Fri, 30 Jul 2021 01:53:40 -0700, Matthew Auld wrote:
>
> On discrete we only support the new fixed mode.
>
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: Ramalingam C <ramalingam.c@intel.com>
> ---
> lib/i915/gem_mman.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/lib/i915/gem_mman.c b/lib/i915/gem_mman.c
> index c432bb16..563a7ccf 100644
> --- a/lib/i915/gem_mman.c
> +++ b/lib/i915/gem_mman.c
> @@ -474,8 +474,14 @@ void *gem_mmap__cpu(int fd, uint32_t handle, uint64_t offset, uint64_t size, uns
> void *__gem_mmap_offset__cpu(int fd, uint32_t handle, uint64_t offset,
> uint64_t size, unsigned prot)
> {
> - return __gem_mmap_offset(fd, handle, offset, size, prot,
> + void *ptr;
> +
> + ptr = __gem_mmap_offset(fd, handle, offset, size, prot,
> I915_MMAP_OFFSET_WB);
> + if (!ptr)
> + ptr = __gem_mmap_offset__fixed(fd, handle, offset, size, prot);
> +
> + return ptr;

Imo there's some asymmetry here. If we are adding fixed mode to
mmap__device_coherent (in the previous patch) then we should also be adding
it to mmap__cpu_coherent (as before). Or, if we are adding fixed mode to
__gem_mmap_offset__cpu we should also be adding it to
__gem_mmap_offset__wc. Thanks.