On Tue, 22 Jul 2025 20:17:14 +0100 Adrian Larumbe <[email protected]> wrote:
> On 07.07.2025 17:04, Caterina Shablia wrote: > > From: Boris Brezillon <[email protected]> > > > > We are going to add flags/properties that will impact the VA merging > > ability. Instead of sprinkling tests all over the place in > > __drm_gpuvm_sm_map(), let's add a helper aggregating all these checks > > can call it for every existing VA we walk through in the > > __drm_gpuvm_sm_map() loop. > > > > Signed-off-by: Boris Brezillon <[email protected]> > > Signed-off-by: Caterina Shablia <[email protected]> > > --- > > drivers/gpu/drm/drm_gpuvm.c | 47 +++++++++++++++++++++++++++++-------- > > 1 file changed, 37 insertions(+), 10 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_gpuvm.c b/drivers/gpu/drm/drm_gpuvm.c > > index 05978c5c38b1..dc3c2f906400 100644 > > --- a/drivers/gpu/drm/drm_gpuvm.c > > +++ b/drivers/gpu/drm/drm_gpuvm.c > > @@ -2098,12 +2098,48 @@ op_unmap_cb(const struct drm_gpuvm_ops *fn, void > > *priv, > > return fn->sm_step_unmap(&op, priv); > > } > > > > +static bool can_merge(struct drm_gpuvm *gpuvm, const struct drm_gpuva *a, > > + const struct drm_gpuva *b) > > +{ > > + /* Only GEM-based mappings can be merged, and they must point to > > + * the same GEM object. > > + */ > > + if (a->gem.obj != b->gem.obj || !a->gem.obj) > > + return false; > > + > > + /* Let's keep things simple for now and force all flags to match. */ > > + if (a->flags != b->flags) > > + return false; > > + > > + /* Order VAs for the rest of the checks. */ > > + if (a->va.addr > b->va.addr) > > + swap(a, b); > > + > > + /* We assume the caller already checked that VAs overlap or are > > + * contiguous. > > + */ > > + if (drm_WARN_ON(gpuvm->drm, b->va.addr > a->va.addr + a->va.range)) > > + return false; > > + > > + /* We intentionally ignore u64 underflows because all we care about > > + * here is whether the VA diff matches the GEM offset diff. > > + */ > > + return b->va.addr - a->va.addr == b->gem.offset - a->gem.offset; > > If we're reordering the VAs for the rest of the checks, when could underflow > happen? I think this comments predates the re-ordering (I originally tried not to order VAs). > > > +} > > + > > static int > > __drm_gpuvm_sm_map(struct drm_gpuvm *gpuvm, > > const struct drm_gpuvm_ops *ops, void *priv, > > const struct drm_gpuvm_map_req *req) > > { > > struct drm_gpuva *va, *next; > > + struct drm_gpuva reqva = { > > + .va.addr = req->va.addr, > > + .va.range = req->va.range, > > + .gem.offset = req->gem.offset, > > + .gem.obj = req->gem.obj, > > + .flags = req->flags, > > + }; > > u64 req_end = req->va.addr + req->va.range; > > int ret; > > > > @@ -2116,12 +2152,9 @@ __drm_gpuvm_sm_map(struct drm_gpuvm *gpuvm, > > u64 addr = va->va.addr; > > u64 range = va->va.range; > > u64 end = addr + range; > > - bool merge = !!va->gem.obj; > > + bool merge = can_merge(gpuvm, va, &reqva); > > > > if (addr == req->va.addr) { > > - merge &= obj == req->gem.obj && > > - offset == req->gem.offset; > > - > > if (end == req_end) { > > ret = op_unmap_cb(ops, priv, va, merge); > > if (ret) > > @@ -2163,8 +2196,6 @@ __drm_gpuvm_sm_map(struct drm_gpuvm *gpuvm, > > }; > > struct drm_gpuva_op_unmap u = { .va = va }; > > > > - merge &= obj == req->gem.obj && > > - offset + ls_range == req->gem.offset; > > u.keep = merge; > > > > if (end == req_end) { > > @@ -2196,10 +2227,6 @@ __drm_gpuvm_sm_map(struct drm_gpuvm *gpuvm, > > break; > > } > > } else if (addr > req->va.addr) { > > - merge &= obj == req->gem.obj && > > - offset == req->gem.offset + > > - (addr - req->va.addr); > > - > > if (end == req_end) { > > ret = op_unmap_cb(ops, priv, va, merge); > > if (ret) > > -- > > 2.47.2 > > > Adrian Larumbe
