From nobody Wed Sep 10 11:14:23 2025 Received: from mail-wr1-f73.google.com (mail-wr1-f73.google.com [209.85.221.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EC03234AB04 for ; Fri, 5 Sep 2025 12:11:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757074301; cv=none; b=bXvSgOkjKOS6yGeXvfwddCrv3yx7O11q8UpCFlxtQKzRuaND3KmTqv3NBoPUDsGGr8aFgQB0TySUWm0MdMuseMDnivnphFFqJJaMxD+B88Q2Ik7pdQmKiIiIQM5425wYLWgDvb6XysgSYvvU3pSi1f4e7U3i28UbTMIiWTK5J7k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757074301; c=relaxed/simple; bh=s2GWvmQHUwyjohU1GP99f3t5sldgnhLD+nr53UBS7jk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=GRq/QIL5Xeb70lB9odJOZxcRq0B6rFPKFdNE9y8kdtK4GYUEm9JwwbkABJOPy09uLk5S0xMXyAsjFfWUnPXD8sjzoGbAMVJ8XpH2sjUaoFH2hWMUqiJbzt6gMkd6bfFlG5QwvAVkhFqo05oF/XZWBxlVTnnx2dXPvnFz4UrPmAY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=WKd3WOvV; arc=none smtp.client-ip=209.85.221.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="WKd3WOvV" Received: by mail-wr1-f73.google.com with SMTP id ffacd0b85a97d-3db89e4f443so1250466f8f.1 for ; Fri, 05 Sep 2025 05:11:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1757074298; x=1757679098; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=rlxAeSfJx82pksd3I0ixRoBKWGI7viD6A795f500XFc=; b=WKd3WOvV/fX9A/edpAjQmhgiha+Y5JvK5wP98yYI4l2HqBBd8Jqb9FQFDiOk+O8dQZ 4pbfz1JywqRx6H9QTMEW7mtjIMe1GhC4Iiu7H+AF2JMXTD6mgpVapjRxSmlxt8uGTgyN 6NIDiP+S5asiVsBMSwu81kH+I6sPTYYB//JVWc0hfAyl52++6iQYtP7UFJYOGsfXORO6 DOauCPvyrpJSOq3L/GYfi0D+llwK5sXV4FF3KQzaEPEpbPgXZF3ssC3R4mXYOXb9/sYt nAJfYm5W1P/kpIUkaWDB8LtOgbAgSAobDdrw7IOjnTxU3mqqaLygE+m/KDrgtCbhVmEC u9WQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757074298; x=1757679098; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=rlxAeSfJx82pksd3I0ixRoBKWGI7viD6A795f500XFc=; b=C9Y+259DoPhKPV6TJW29w+MvU1LnLo8+i79BggvMLS/B/dJXmhorjDvgzAf1sglRPm OWDHbCfXv47Ub11heUAEJfrvCA3gsjc0Imzh9YWePb7uX06b7blQuIwT/9oLFo0OSFRK RDtMClBsiMkV9lg1OvDXzzTyYRXMqRCp6Kr3Mn0FDDliaPvQeemJnqY/PM1M0UJHqwS9 Cu/wSsn8zQHNlTCTlQqmmpIJAmt2GacFHaI8EygZgjK99xajlVG+UfDMcYetqzO9Q7AU 8XZQNAFgXehpzQq6REloSkaLYstQqOx6OPQY46KrdC0dkjfy+L55PpE9vlFxLYFLAmzl aNOQ== X-Forwarded-Encrypted: i=1; AJvYcCXK87WB2doAQCf1tCOjGpuHRocu1fadaLTWlZcQzMCpI0lelIKeh5JbEwsxDvWKJLFQHPYgWubDWvIqG14=@vger.kernel.org X-Gm-Message-State: AOJu0YzYofXHJdzdbaZuEc0n1FlNqeXF4jUlfnwnUGAQJRA46rWcRo2P VYyqGKp+oP8zK4PuzUsxdYMV4OyTtjmnWO462jjU4hYIQThpHdBczwCW6oC+CCSUNhkD1RU6uLT sk54tWLIHK2foYrrIxw== X-Google-Smtp-Source: AGHT+IG8jYGvzO4xJ5XE6YjDlUyoq7XkUoX06psrVfvh6sWFTCcB4r+O6TwY74/lyIP1l3hTEjNDm+Em6qNSRZg= X-Received: from wrml12.prod.google.com ([2002:adf:e58c:0:b0:3d5:28fd:8822]) (user=aliceryhl job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6000:2008:b0:3e4:e4e:343c with SMTP id ffacd0b85a97d-3e40e4e3a79mr1309181f8f.31.1757074298331; Fri, 05 Sep 2025 05:11:38 -0700 (PDT) Date: Fri, 05 Sep 2025 12:11:29 +0000 In-Reply-To: <20250905-vmbo-defer-v1-0-7ae1a382b674@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250905-vmbo-defer-v1-0-7ae1a382b674@google.com> X-Developer-Key: i=aliceryhl@google.com; a=openpgp; fpr=49F6C1FAA74960F43A5B86A1EE7A392FDE96209F X-Developer-Signature: v=1; a=openpgp-sha256; l=9037; i=aliceryhl@google.com; h=from:subject:message-id; bh=s2GWvmQHUwyjohU1GP99f3t5sldgnhLD+nr53UBS7jk=; b=owEBbQKS/ZANAwAKAQRYvu5YxjlGAcsmYgBoutN24be3/jGNmEoz+LMXQuVQHZUNhQi1vI/sM vYnnqGZy56JAjMEAAEKAB0WIQSDkqKUTWQHCvFIvbIEWL7uWMY5RgUCaLrTdgAKCRAEWL7uWMY5 RnFLD/4rxL4E5zD6NMkjopiwv+rIBm+fmYOSzbi9ShMG5wEXGT4QaQJ+TE+y3VvWuCZOh3JDa+C /QgvOypoW/eu9nRIWFJBqv4IOHI95WV5lkqr7IA0UGuXUY/Zg/Gcy0wWj4xWigAZa6jw/mpNToU +W8LpBpz8qYuUzY/bpjDLndzUDrym7j18IZ8b/zayd8x2Il+/Zjdal4o0CH0UXH/avk+5Fsiiz+ JtLFl8SSJEzVtweaL7x06H7+/yIN5ReqckjUv4ivszj6THkoi/iyCyBOtHu/sFkTY7+gVAS24Ak Jv2cOSuEdMOiJ88XgijiMFOfnw3WWW+ZiiT3Akk+lMiohEPanm7/pcJezQhDIljbkljNTewf7Ny vaQhnVKdAkqr4wh0eXJkAdj9E7JAK0UpyuZ7JpcjGSygEsPS5wVM7gGnWfOWd54RIQqIB5Tybua ZTshg2aOXcrpt8Fac24t45e00wSuhFCK3W6WMfu88bXG0IlJF2mhKNiUrxQ+IwEJekwKQHvhqLo uRmIvBykWbMPCn6fsX2w2CdtN5lYHA4xy1uzcv66t3kBpbDeJQ57/U3EGrZOQGOUj+Rl8EOTjYH tsSLFgPM+0nsr+KOl8x8hfwbfYVKw71Ou6ywZvfBIfFwFD6AyMMvCqv7To3iHeu82gUkEZ3NYS+ ywfT3BM2QDRI5Yg== X-Mailer: b4 0.14.2 Message-ID: <20250905-vmbo-defer-v1-2-7ae1a382b674@google.com> Subject: [PATCH 2/2] panthor: use drm_gpuva_unlink_defer() From: Alice Ryhl To: Danilo Krummrich , Matthew Brost , "=?utf-8?q?Thomas_Hellstr=C3=B6m?=" Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Boris Brezillon , Steven Price , Daniel Almeida , Liviu Dudau , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, Alice Ryhl Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Instead of manually deferring cleanup of vm_bos, use the new GPUVM infrastructure for doing so. To avoid manual management of vm_bo refcounts, the panthor_vma_link() and panthor_vma_unlink() methods are changed to get and put a vm_bo refcount on the vm_bo. This simplifies the code a lot. I preserved the behavior where panthor_gpuva_sm_step_map() drops the refcount right away rather than letting panthor_vm_cleanup_op_ctx() do it later. Signed-off-by: Alice Ryhl --- drivers/gpu/drm/panthor/panthor_mmu.c | 112 ++++++------------------------= ---- 1 file changed, 18 insertions(+), 94 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/pantho= r/panthor_mmu.c index 6dec4354e3789d17c5a87fc8de3bc86764b804bc..4922da0b106aec2bdf657ce4c59= 6acb9c63797ce 100644 --- a/drivers/gpu/drm/panthor/panthor_mmu.c +++ b/drivers/gpu/drm/panthor/panthor_mmu.c @@ -181,20 +181,6 @@ struct panthor_vm_op_ctx { u64 range; } va; =20 - /** - * @returned_vmas: List of panthor_vma objects returned after a VM operat= ion. - * - * For unmap operations, this will contain all VMAs that were covered by = the - * specified VA range. - * - * For map operations, this will contain all VMAs that previously mapped = to - * the specified VA range. - * - * Those VMAs, and the resources they point to will be released as part of - * the op_ctx cleanup operation. - */ - struct list_head returned_vmas; - /** @map: Fields specific to a map operation. */ struct { /** @map.vm_bo: Buffer object to map. */ @@ -1081,47 +1067,18 @@ void panthor_vm_free_va(struct panthor_vm *vm, stru= ct drm_mm_node *va_node) mutex_unlock(&vm->mm_lock); } =20 -static void panthor_vm_bo_put(struct drm_gpuvm_bo *vm_bo) +static void panthor_vm_bo_free(struct drm_gpuvm_bo *vm_bo) { struct panthor_gem_object *bo =3D to_panthor_bo(vm_bo->obj); - struct drm_gpuvm *vm =3D vm_bo->vm; - bool unpin; - - /* We must retain the GEM before calling drm_gpuvm_bo_put(), - * otherwise the mutex might be destroyed while we hold it. - * Same goes for the VM, since we take the VM resv lock. - */ - drm_gem_object_get(&bo->base.base); - drm_gpuvm_get(vm); - - /* We take the resv lock to protect against concurrent accesses to the - * gpuvm evicted/extobj lists that are modified in - * drm_gpuvm_bo_destroy(), which is called if drm_gpuvm_bo_put() - * releases sthe last vm_bo reference. - * We take the BO GPUVA list lock to protect the vm_bo removal from the - * GEM vm_bo list. - */ - dma_resv_lock(drm_gpuvm_resv(vm), NULL); - mutex_lock(&bo->base.base.gpuva.lock); - unpin =3D drm_gpuvm_bo_put(vm_bo); - mutex_unlock(&bo->base.base.gpuva.lock); - dma_resv_unlock(drm_gpuvm_resv(vm)); =20 - /* If the vm_bo object was destroyed, release the pin reference that - * was hold by this object. - */ - if (unpin && !drm_gem_is_imported(&bo->base.base)) + if (!drm_gem_is_imported(&bo->base.base)) drm_gem_shmem_unpin(&bo->base); - - drm_gpuvm_put(vm); - drm_gem_object_put(&bo->base.base); + kfree(vm_bo); } =20 static void panthor_vm_cleanup_op_ctx(struct panthor_vm_op_ctx *op_ctx, struct panthor_vm *vm) { - struct panthor_vma *vma, *tmp_vma; - u32 remaining_pt_count =3D op_ctx->rsvd_page_tables.count - op_ctx->rsvd_page_tables.ptr; =20 @@ -1134,16 +1091,12 @@ static void panthor_vm_cleanup_op_ctx(struct pantho= r_vm_op_ctx *op_ctx, kfree(op_ctx->rsvd_page_tables.pages); =20 if (op_ctx->map.vm_bo) - panthor_vm_bo_put(op_ctx->map.vm_bo); + drm_gpuvm_bo_put_deferred(op_ctx->map.vm_bo); =20 for (u32 i =3D 0; i < ARRAY_SIZE(op_ctx->preallocated_vmas); i++) kfree(op_ctx->preallocated_vmas[i]); =20 - list_for_each_entry_safe(vma, tmp_vma, &op_ctx->returned_vmas, node) { - list_del(&vma->node); - panthor_vm_bo_put(vma->base.vm_bo); - kfree(vma); - } + drm_gpuvm_bo_deferred_cleanup(&vm->base); } =20 static struct panthor_vma * @@ -1232,7 +1185,6 @@ static int panthor_vm_prepare_map_op_ctx(struct panth= or_vm_op_ctx *op_ctx, return -EINVAL; =20 memset(op_ctx, 0, sizeof(*op_ctx)); - INIT_LIST_HEAD(&op_ctx->returned_vmas); op_ctx->flags =3D flags; op_ctx->va.range =3D size; op_ctx->va.addr =3D va; @@ -1243,7 +1195,9 @@ static int panthor_vm_prepare_map_op_ctx(struct panth= or_vm_op_ctx *op_ctx, =20 if (!drm_gem_is_imported(&bo->base.base)) { /* Pre-reserve the BO pages, so the map operation doesn't have to - * allocate. + * allocate. This pin is dropped in panthor_vm_bo_free(), so + * once we call drm_gpuvm_bo_create(), GPUVM will take care of + * dropping the pin for us. */ ret =3D drm_gem_shmem_pin(&bo->base); if (ret) @@ -1263,9 +1217,6 @@ static int panthor_vm_prepare_map_op_ctx(struct panth= or_vm_op_ctx *op_ctx, =20 preallocated_vm_bo =3D drm_gpuvm_bo_create(&vm->base, &bo->base.base); if (!preallocated_vm_bo) { - if (!drm_gem_is_imported(&bo->base.base)) - drm_gem_shmem_unpin(&bo->base); - ret =3D -ENOMEM; goto err_cleanup; } @@ -1282,16 +1233,6 @@ static int panthor_vm_prepare_map_op_ctx(struct pant= hor_vm_op_ctx *op_ctx, mutex_unlock(&bo->base.base.gpuva.lock); dma_resv_unlock(panthor_vm_resv(vm)); =20 - /* If the a vm_bo for this combination exists, it already - * retains a pin ref, and we can release the one we took earlier. - * - * If our pre-allocated vm_bo is picked, it now retains the pin ref, - * which will be released in panthor_vm_bo_put(). - */ - if (preallocated_vm_bo !=3D op_ctx->map.vm_bo && - !drm_gem_is_imported(&bo->base.base)) - drm_gem_shmem_unpin(&bo->base); - op_ctx->map.bo_offset =3D offset; =20 /* L1, L2 and L3 page tables. @@ -1339,7 +1280,6 @@ static int panthor_vm_prepare_unmap_op_ctx(struct pan= thor_vm_op_ctx *op_ctx, int ret; =20 memset(op_ctx, 0, sizeof(*op_ctx)); - INIT_LIST_HEAD(&op_ctx->returned_vmas); op_ctx->va.range =3D size; op_ctx->va.addr =3D va; op_ctx->flags =3D DRM_PANTHOR_VM_BIND_OP_TYPE_UNMAP; @@ -1387,7 +1327,6 @@ static void panthor_vm_prepare_sync_only_op_ctx(struc= t panthor_vm_op_ctx *op_ctx struct panthor_vm *vm) { memset(op_ctx, 0, sizeof(*op_ctx)); - INIT_LIST_HEAD(&op_ctx->returned_vmas); op_ctx->flags =3D DRM_PANTHOR_VM_BIND_OP_TYPE_SYNC_ONLY; } =20 @@ -2033,26 +1972,12 @@ static void panthor_vma_link(struct panthor_vm *vm, =20 mutex_lock(&bo->base.base.gpuva.lock); drm_gpuva_link(&vma->base, vm_bo); - drm_WARN_ON(&vm->ptdev->base, drm_gpuvm_bo_put(vm_bo)); mutex_unlock(&bo->base.base.gpuva.lock); } =20 -static void panthor_vma_unlink(struct panthor_vm *vm, - struct panthor_vma *vma) +static void panthor_vma_unlink(struct panthor_vma *vma) { - struct panthor_gem_object *bo =3D to_panthor_bo(vma->base.gem.obj); - struct drm_gpuvm_bo *vm_bo =3D drm_gpuvm_bo_get(vma->base.vm_bo); - - mutex_lock(&bo->base.base.gpuva.lock); - drm_gpuva_unlink(&vma->base); - mutex_unlock(&bo->base.base.gpuva.lock); - - /* drm_gpuva_unlink() release the vm_bo, but we manually retained it - * when entering this function, so we can implement deferred VMA - * destruction. Re-assign it here. - */ - vma->base.vm_bo =3D vm_bo; - list_add_tail(&vma->node, &vm->op_ctx->returned_vmas); + drm_gpuva_unlink_defer(&vma->base); } =20 static void panthor_vma_init(struct panthor_vma *vma, u32 flags) @@ -2084,12 +2009,12 @@ static int panthor_gpuva_sm_step_map(struct drm_gpu= va_op *op, void *priv) if (ret) return ret; =20 - /* Ref owned by the mapping now, clear the obj field so we don't release = the - * pinning/obj ref behind GPUVA's back. - */ drm_gpuva_map(&vm->base, &vma->base, &op->map); panthor_vma_link(vm, vma, op_ctx->map.vm_bo); + + drm_gpuvm_bo_put_deferred(op_ctx->map.vm_bo); op_ctx->map.vm_bo =3D NULL; + return 0; } =20 @@ -2128,16 +2053,14 @@ static int panthor_gpuva_sm_step_remap(struct drm_g= puva_op *op, * owned by the old mapping which will be released when this * mapping is destroyed, we need to grab a ref here. */ - panthor_vma_link(vm, prev_vma, - drm_gpuvm_bo_get(op->remap.unmap->va->vm_bo)); + panthor_vma_link(vm, prev_vma, op->remap.unmap->va->vm_bo); } =20 if (next_vma) { - panthor_vma_link(vm, next_vma, - drm_gpuvm_bo_get(op->remap.unmap->va->vm_bo)); + panthor_vma_link(vm, next_vma, op->remap.unmap->va->vm_bo); } =20 - panthor_vma_unlink(vm, unmap_vma); + panthor_vma_unlink(unmap_vma); return 0; } =20 @@ -2154,12 +2077,13 @@ static int panthor_gpuva_sm_step_unmap(struct drm_g= puva_op *op, return ret; =20 drm_gpuva_unmap(&op->unmap); - panthor_vma_unlink(vm, unmap_vma); + panthor_vma_unlink(unmap_vma); return 0; } =20 static const struct drm_gpuvm_ops panthor_gpuvm_ops =3D { .vm_free =3D panthor_vm_free, + .vm_bo_free =3D panthor_vm_bo_free, .sm_step_map =3D panthor_gpuva_sm_step_map, .sm_step_remap =3D panthor_gpuva_sm_step_remap, .sm_step_unmap =3D panthor_gpuva_sm_step_unmap, --=20 2.51.0.355.g5224444f11-goog