From patchwork Fri Feb 8 15:37:02 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Wilson X-Patchwork-Id: 10803297 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 36C291575 for ; Fri, 8 Feb 2019 15:37:16 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 272B12E92D for ; Fri, 8 Feb 2019 15:37:16 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1B56F2E932; Fri, 8 Feb 2019 15:37:16 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id AFB6C2E92D for ; Fri, 8 Feb 2019 15:37:15 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2B3566EE2D; Fri, 8 Feb 2019 15:37:14 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from fireflyinternet.com (mail.fireflyinternet.com [109.228.58.192]) by gabe.freedesktop.org (Postfix) with ESMTPS id 371F16EE2B for ; Fri, 8 Feb 2019 15:37:12 +0000 (UTC) X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Received: from haswell.alporthouse.com (unverified [78.156.65.138]) by fireflyinternet.com (Firefly Internet (M1)) with ESMTP id 15511797-1500050 for ; Fri, 08 Feb 2019 15:37:08 +0000 From: Chris Wilson To: intel-gfx@lists.freedesktop.org Date: Fri, 8 Feb 2019 15:37:02 +0000 Message-Id: <20190208153708.20023-1-chris@chris-wilson.co.uk> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Subject: [Intel-gfx] [CI 1/7] drm/i915: Defer removing fence register tracking to rpm wakeup X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP Currently, we may simultaneously release the fence register from both fence_update() and i915_gem_restore_fences(). This is dangerous, so defer the bookkeeping entirely to i915_gem_restore_fences() when the device is asleep. Reported-by: Mika Kuoppala Signed-off-by: Chris Wilson Cc: Mika Kuoppala Reviewed-by: Mika Kuoppala --- drivers/gpu/drm/i915/i915_gem_fence_reg.c | 62 ++++++++++++----------- 1 file changed, 32 insertions(+), 30 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_fence_reg.c b/drivers/gpu/drm/i915/i915_gem_fence_reg.c index e037e94792f3..be89bd95ab7c 100644 --- a/drivers/gpu/drm/i915/i915_gem_fence_reg.c +++ b/drivers/gpu/drm/i915/i915_gem_fence_reg.c @@ -210,6 +210,7 @@ static int fence_update(struct drm_i915_fence_reg *fence, struct i915_vma *vma) { intel_wakeref_t wakeref; + struct i915_vma *old; int ret; if (vma) { @@ -229,49 +230,55 @@ static int fence_update(struct drm_i915_fence_reg *fence, return ret; } - if (fence->vma) { - struct i915_vma *old = fence->vma; - + old = xchg(&fence->vma, NULL); + if (old) { ret = i915_active_request_retire(&old->last_fence, &old->obj->base.dev->struct_mutex); - if (ret) + if (ret) { + fence->vma = old; return ret; + } i915_vma_flush_writes(old); - } - if (fence->vma && fence->vma != vma) { - /* Ensure that all userspace CPU access is completed before + /* + * Ensure that all userspace CPU access is completed before * stealing the fence. */ - GEM_BUG_ON(fence->vma->fence != fence); - i915_vma_revoke_mmap(fence->vma); - - fence->vma->fence = NULL; - fence->vma = NULL; + if (old != vma) { + GEM_BUG_ON(old->fence != fence); + i915_vma_revoke_mmap(old); + old->fence = NULL; + } list_move(&fence->link, &fence->i915->mm.fence_list); } - /* We only need to update the register itself if the device is awake. + /* + * We only need to update the register itself if the device is awake. * If the device is currently powered down, we will defer the write * to the runtime resume, see i915_gem_restore_fences(). + * + * This only works for removing the fence register, on acquisition + * the caller must hold the rpm wakeref. The fence register must + * be cleared before we can use any other fences to ensure that + * the new fences do not overlap the elided clears, confusing HW. */ wakeref = intel_runtime_pm_get_if_in_use(fence->i915); - if (wakeref) { - fence_write(fence, vma); - intel_runtime_pm_put(fence->i915, wakeref); + if (!wakeref) { + GEM_BUG_ON(vma); + return 0; } - if (vma) { - if (fence->vma != vma) { - vma->fence = fence; - fence->vma = vma; - } + fence_write(fence, vma); + fence->vma = vma; + if (vma) { + vma->fence = fence; list_move_tail(&fence->link, &fence->i915->mm.fence_list); } + intel_runtime_pm_put(fence->i915, wakeref); return 0; } @@ -473,9 +480,10 @@ void i915_gem_restore_fences(struct drm_i915_private *dev_priv) { int i; + rcu_read_lock(); /* keep obj alive as we dereference */ for (i = 0; i < dev_priv->num_fence_regs; i++) { struct drm_i915_fence_reg *reg = &dev_priv->fence_regs[i]; - struct i915_vma *vma = reg->vma; + struct i915_vma *vma = READ_ONCE(reg->vma); GEM_BUG_ON(vma && vma->fence != reg); @@ -483,18 +491,12 @@ void i915_gem_restore_fences(struct drm_i915_private *dev_priv) * Commit delayed tiling changes if we have an object still * attached to the fence, otherwise just clear the fence. */ - if (vma && !i915_gem_object_is_tiled(vma->obj)) { - GEM_BUG_ON(!reg->dirty); - GEM_BUG_ON(i915_vma_has_userfault(vma)); - - list_move(®->link, &dev_priv->mm.fence_list); - vma->fence = NULL; + if (vma && !i915_gem_object_is_tiled(vma->obj)) vma = NULL; - } fence_write(reg, vma); - reg->vma = vma; } + rcu_read_unlock(); } /**