From nobody Wed Sep 10 11:07:13 2025 Received: from mail-ej1-f74.google.com (mail-ej1-f74.google.com [209.85.218.74]) (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 E8D4B342C89 for ; Tue, 9 Sep 2025 13:36:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.74 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757425002; cv=none; b=he6T4s7jb+IZMypX/20RNW7ZigCopzFA48/dfs9LPT86KZPJyc1d7DQEUcucpVhBpqPtfvNBim+iwjfcv2War9BTcMgKlpStyr9uFqcqtjBdiQ5rrPjl1MkQ87qOz1PxOfLQNP5AYCPHY6/cfVNZP8PBmKovFwgUouLlu8FJiFM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757425002; c=relaxed/simple; bh=/Lhwto5s1ginBRFK1K461SpzI0kY9fIX6onz0SIu1pA=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=JSeiDcAqiWU9GjT67UsHeeCorgD/sE5oTcvC+rpELGKbjbHDHFkGMwiW+n15Zg1BOO6URSLvkIswrD2b/nq5g7YABFi1eaD1eJoF3xef4EVp+fWSrsxwfnkbSSncEBkrYeKuL5EY6learATatg12L0DBCPBmMePJSeCz5KBGF/Q= 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=hoisQODg; arc=none smtp.client-ip=209.85.218.74 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="hoisQODg" Received: by mail-ej1-f74.google.com with SMTP id a640c23a62f3a-b044a42959dso469652466b.1 for ; Tue, 09 Sep 2025 06:36:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1757424998; x=1758029798; 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=MmbSiSnFwTIoU/JLu47n8SFv5vhZb2klpFQfcVoTQdo=; b=hoisQODganKj576fIsZYv7zrOaZOz/kS+mzFu4bpEU59byiVAZYThzzy5PAjVcx/ag Q3yFyUIDjw1fAys7FlenQSq/hpxKYnARx9pBQiv/0yjUnXZ/gSluTxDIDoiH4N6hKmE9 J2GrJEZWYgA88R2nFQpu2Mj1A1hLhZjObJMmzePMXvN8bTLgWZzEIGC5ju/VE0dVR/l1 x4kgXGnp7SDQVxICXpOA68Qswp+oL2xMXzzWePBDTiAq7P+Ycp7WT7EmovAUnjgESruR 51MixevmPHoO5IfTAh4eKRVQHHwhPzzut8mvODa8A37IbvPbud/L2jw74IdIo4FXgKbX AnFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1757424998; x=1758029798; 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=MmbSiSnFwTIoU/JLu47n8SFv5vhZb2klpFQfcVoTQdo=; b=PvfgsRXiMA+iENets/ZS8Ud1LwJ237EccrSW6R2DV06WxikI6daXpyylc3vOcguP6D IzSsF7zsvFCivXpcFVpU5uqbfsjfJmkFd8/PNh9MyGbLAuxJLtrLyhydiN1CMfGG5HuP 2ov24dIydJLga8ZIzR4sR2IGLaaYz5MFaN+oxEszSMFnuLMT0/0M1xE4VmQMFExpxZKw ZS1Sp6MN5MLQbcVE7muKq/0HBrAX0vEbN7dCVKVl3/U0ol/8yMrStDnAcYLwKo/ZX8Oi bUkyg3tLfrBiaKlBcHFXZqGRGoJj6ojzpuxlr7ubU8JyatWTdXNEx8eNc7RO1keiaOxp uqJQ== X-Forwarded-Encrypted: i=1; AJvYcCVdQblW3qfQK6PpVetXWP8LPsu2WhSn6BSow4VUnerUQlfvVWWaHvx2b26OPTgnB/uIyLdK3u6r2Dn4Y+A=@vger.kernel.org X-Gm-Message-State: AOJu0YwAB2djVnbObIL2bCdWpLVn+Lnk3Dd/18sS2RYXQkSvS+42peco pPAOia1f0i42Q2BVAz7RBR2UZ+gt1d8NEEo6K6bQMADHVxozY4qvmt9q6x9J3bOkmNT7vgd7LKV agclH01bfJKluRWcgUw== X-Google-Smtp-Source: AGHT+IFAFV8+5PF+ACjxRZtS035sPxF/aJB68T82HGLHJTP0jManXfiLAOmflSk4J9V4JiFGh4CY21p9NhaMWQs= X-Received: from ejcwb15.prod.google.com ([2002:a17:907:d50f:b0:b04:b988:644c]) (user=aliceryhl job=prod-delivery.src-stubby-dispatcher) by 2002:a17:907:7e97:b0:b04:590a:a5b5 with SMTP id a640c23a62f3a-b04b1480b35mr1159064666b.24.1757424998120; Tue, 09 Sep 2025 06:36:38 -0700 (PDT) Date: Tue, 09 Sep 2025 13:36:23 +0000 In-Reply-To: <20250909-vmbo-defer-v2-0-9835d7349089@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250909-vmbo-defer-v2-0-9835d7349089@google.com> X-Developer-Key: i=aliceryhl@google.com; a=openpgp; fpr=49F6C1FAA74960F43A5B86A1EE7A392FDE96209F X-Developer-Signature: v=1; a=openpgp-sha256; l=9052; i=aliceryhl@google.com; h=from:subject:message-id; bh=/Lhwto5s1ginBRFK1K461SpzI0kY9fIX6onz0SIu1pA=; b=owEBbQKS/ZANAwAKAQRYvu5YxjlGAcsmYgBowC1iqBKdGP913iBnrFCBvAIMxLF+7dvDJhtb2 Vee9/V2NAaJAjMEAAEKAB0WIQSDkqKUTWQHCvFIvbIEWL7uWMY5RgUCaMAtYgAKCRAEWL7uWMY5 RkphD/wP6DfltzHI35xh9b46K2Va3My+E/65DQgQrsGjn8TnLx0MNvKWfTFhCKUJ7Yf4s3xNI0o hgqT3PsMCIjk1bvG3r1c2MH3ghPLrHKTbrVBDkcwj9eV6jRKHv8c+jr4JrjyISA+mezUEnzuVqX FUXuV6d+SplJlxzYudj2Q/Yfv36GLy4IAw+AVCv5hNGiSPbxaLVZ2JEJqlNcEoQJBoxmX9mCK8Z /HFEKGc8/ZlANMl9QAZQ6pYi5Z9hAxaU1bzVJRJGSYVRsa+YfaeSKvUdwRZNFwMmLsjGoE0c2mt tXqsqlBD/qdD6DXHqBfVNWcliItpZ17a4Podaojbn6djlv+QgbQ9DduO+JJPpbnU1UNHa2RxRpI vHRxQQcs4v0T1EGB7jmR49iqmmi9TjmbKRNJee2YZhpPcIY9wgj8fO09urMOKUACbizl3kVZAsO l9BBQ9ARwKox0AljkS9YJ2kwMFbydO8ZwyalgvYEoIO/UhOIxBel9uaolFWzuzo6F+f22ylS0TT 8QnI2rh92RwoqgqC+t8nJBM848s95+SW/wfhV2iaOJYm34TJKrfejU8e+RsnGOHXCQnX/B/G5xc HpfFNrYDrxIMpzlQ9c/0s6jj4Aoks5WfgPVGDJsz/MOQ28iF0ucIYXRdKEfagqIRcvX7BbKzRy/ 6PXqXitUFAi/Elg== X-Mailer: b4 0.14.2 Message-ID: <20250909-vmbo-defer-v2-2-9835d7349089@google.com> Subject: [PATCH v2 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 | 113 ++++++------------------------= ---- 1 file changed, 19 insertions(+), 94 deletions(-) diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/pantho= r/panthor_mmu.c index 6dec4354e3789d17c5a87fc8de3bc86764b804bc..fd9ed88a4259e5fb88e5acffcf6= d8a658cc7115d 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 +1972,13 @@ 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); + kfree(vma); } =20 static void panthor_vma_init(struct panthor_vma *vma, u32 flags) @@ -2084,12 +2010,12 @@ 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 +2054,14 @@ 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 +2078,13 @@ 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 2.51.0.384.g4c02a37b29-goog