From patchwork Mon Feb 29 21:16:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Gordon X-Patchwork-Id: 8458371 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id C23589F65E for ; Mon, 29 Feb 2016 21:17:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id ABFEC20221 for ; Mon, 29 Feb 2016 21:17:53 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 7D2DE2021A for ; Mon, 29 Feb 2016 21:17:52 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id BD0356E382; Mon, 29 Feb 2016 21:17:51 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id 234036E381 for ; Mon, 29 Feb 2016 21:16:51 +0000 (UTC) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 29 Feb 2016 13:16:51 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.22,521,1449561600"; d="scan'208";a="923744086" Received: from dsgordon-linux2.isw.intel.com ([10.102.226.88]) by orsmga002.jf.intel.com with ESMTP; 29 Feb 2016 13:16:50 -0800 From: Dave Gordon To: intel-gfx@lists.freedesktop.org Date: Mon, 29 Feb 2016 21:16:12 +0000 Message-Id: <1456780572-19196-8-git-send-email-david.s.gordon@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1456780572-19196-1-git-send-email-david.s.gordon@intel.com> References: <1456780572-19196-1-git-send-email-david.s.gordon@intel.com> Organization: Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ Subject: [Intel-gfx] [PATCH v6 7/7] drm/i915: refactor duplicate object vmap functions (reworked again) X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This is essentially Chris Wilson's patch of a similar name, reworked on top of Alex Dai's recent patch: | drm/i915: Add i915_gem_object_vmap to map GEM object to virtual space Chris' original commentary said: | We now have two implementations for vmapping a whole object, one for | dma-buf and one for the ringbuffer. If we couple the vmapping into | the obj->pages lifetime, then we can reuse an obj->vmapping for both | and at the same time couple it into the shrinker. | | v2: Mark the failable kmalloc() as __GFP_NOWARN (vsyrjala) | v3: Call unpin_vmap from the right dmabuf unmapper v4: reimplements the same functionality, but now as wrappers round the recently-introduced i915_gem_object_vmap_range() from Alex's patch mentioned above. v5: separated from two minor but unrelated changes [Tvrtko Ursulin]; this is the third and most substantial portion. Decided not to hold onto vmappings after the pin count goes to zero. This may reduce the benefit of Chris' scheme a bit, but does avoid any increased risk of exhausting kernel vmap space on 32-bit kernels [Tvrtko Ursulin]. Potentially, the vunmap() could be deferred until the put_pages() stage if a suitable notifier were written, but we're not doing that here. Nonetheless, the simplification of both dmabuf and ringbuffer code makes it worthwhile in its own right. v6: change BUG_ON() to WARN_ON(). [Tvrtko Ursulin] Signed-off-by: Dave Gordon Reviewed-by: Tvrtko Ursulin Cc: Chris Wilson Cc: Alex Dai --- drivers/gpu/drm/i915/i915_drv.h | 22 +++++++++++++----- drivers/gpu/drm/i915/i915_gem.c | 40 +++++++++++++++++++++++++++++++++ drivers/gpu/drm/i915/i915_gem_dmabuf.c | 37 ++++-------------------------- drivers/gpu/drm/i915/intel_ringbuffer.c | 10 ++++----- 4 files changed, 66 insertions(+), 43 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 12b0717..754441a 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2172,10 +2172,7 @@ struct drm_i915_gem_object { struct scatterlist *sg; int last; } get_page; - - /* prime dma-buf support */ - void *dma_buf_vmapping; - int vmapping_count; + void *vmapping; /** Breadcrumb of last rendering to the buffer. * There can only be one writer, but we allow for multiple readers. @@ -2980,7 +2977,22 @@ static inline void i915_gem_object_pin_pages(struct drm_i915_gem_object *obj) static inline void i915_gem_object_unpin_pages(struct drm_i915_gem_object *obj) { BUG_ON(obj->pages_pin_count == 0); - obj->pages_pin_count--; + if (--obj->pages_pin_count == 0 && obj->vmapping) { + /* + * Releasing the vmapping here may yield less benefit than + * if we kept it until put_pages(), but on the other hand + * avoids issues of exhausting kernel vmappable address + * space on 32-bit kernels. + */ + vunmap(obj->vmapping); + obj->vmapping = NULL; + } +} + +void *__must_check i915_gem_object_pin_vmap(struct drm_i915_gem_object *obj); +static inline void i915_gem_object_unpin_vmap(struct drm_i915_gem_object *obj) +{ + i915_gem_object_unpin_pages(obj); } void *__must_check i915_gem_object_vmap_range(struct drm_i915_gem_object *obj, diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 9410c72..b17423d 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2235,6 +2235,12 @@ static void i915_gem_object_free_mmap_offset(struct drm_i915_gem_object *obj) ops->put_pages(obj); obj->pages = NULL; + /* vmapping should have been dropped when pages_pin_count went to 0 */ + if (WARN_ON(obj->vmapping)) { + vunmap(obj->vmapping); + obj->vmapping = NULL; + } + i915_gem_object_invalidate(obj); return 0; @@ -2463,6 +2469,40 @@ void *i915_gem_object_vmap_range(struct drm_i915_gem_object *obj, return addr; } +/** + * i915_gem_object_pin_vmap - pin a GEM object and map it into kernel space + * @obj: the GEM object to be mapped + * + * Combines the functions of get_pages(), pin_pages() and vmap_range() on + * the whole object. The caller should release the mapping by calling + * i915_gem_object_unpin_vmap() when it is no longer required. + * + * Returns the address at which the object has been mapped, or an ERR_PTR + * on failure. + */ +void *i915_gem_object_pin_vmap(struct drm_i915_gem_object *obj) +{ + int ret; + + ret = i915_gem_object_get_pages(obj); + if (ret) + return ERR_PTR(ret); + + i915_gem_object_pin_pages(obj); + + if (obj->vmapping == NULL) { + obj->vmapping = i915_gem_object_vmap_range(obj, 0, + obj->base.size); + + if (obj->vmapping == NULL) { + i915_gem_object_unpin_pages(obj); + return ERR_PTR(-ENOMEM); + } + } + + return obj->vmapping; +} + void i915_vma_move_to_active(struct i915_vma *vma, struct drm_i915_gem_request *req) { diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c index 68e21d1..adc7b5e 100644 --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c @@ -108,41 +108,17 @@ static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf) { struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf); struct drm_device *dev = obj->base.dev; + void *addr; int ret; ret = i915_mutex_lock_interruptible(dev); if (ret) return ERR_PTR(ret); - if (obj->dma_buf_vmapping) { - obj->vmapping_count++; - goto out_unlock; - } - - ret = i915_gem_object_get_pages(obj); - if (ret) - goto err; - - i915_gem_object_pin_pages(obj); - - ret = -ENOMEM; - - obj->dma_buf_vmapping = i915_gem_object_vmap_range(obj, 0, - dma_buf->size >> PAGE_SHIFT); - - if (!obj->dma_buf_vmapping) - goto err_unpin; - - obj->vmapping_count = 1; -out_unlock: + addr = i915_gem_object_pin_vmap(obj); mutex_unlock(&dev->struct_mutex); - return obj->dma_buf_vmapping; -err_unpin: - i915_gem_object_unpin_pages(obj); -err: - mutex_unlock(&dev->struct_mutex); - return ERR_PTR(ret); + return addr; } static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr) @@ -151,12 +127,7 @@ static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr) struct drm_device *dev = obj->base.dev; mutex_lock(&dev->struct_mutex); - if (--obj->vmapping_count == 0) { - vunmap(obj->dma_buf_vmapping); - obj->dma_buf_vmapping = NULL; - - i915_gem_object_unpin_pages(obj); - } + i915_gem_object_unpin_vmap(obj); mutex_unlock(&dev->struct_mutex); } diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 15e2d29..47f186e 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -2056,7 +2056,7 @@ static int init_phys_status_page(struct intel_engine_cs *ring) void intel_unpin_ringbuffer_obj(struct intel_ringbuffer *ringbuf) { if (HAS_LLC(ringbuf->obj->base.dev) && !ringbuf->obj->stolen) - vunmap(ringbuf->virtual_start); + i915_gem_object_unpin_vmap(ringbuf->obj); else iounmap(ringbuf->virtual_start); ringbuf->virtual_start = NULL; @@ -2080,10 +2080,10 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev, if (ret) goto unpin; - ringbuf->virtual_start = i915_gem_object_vmap_range(obj, 0, - ringbuf->size >> PAGE_SHIFT); - if (ringbuf->virtual_start == NULL) { - ret = -ENOMEM; + ringbuf->virtual_start = i915_gem_object_pin_vmap(obj); + if (IS_ERR(ringbuf->virtual_start)) { + ret = PTR_ERR(ringbuf->virtual_start); + ringbuf->virtual_start = NULL; goto unpin; } } else {