From patchwork Thu Feb 27 18:30:02 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Widawsky X-Patchwork-Id: 3735111 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id E468DBF13A for ; Thu, 27 Feb 2014 18:30:12 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 09C3B20142 for ; Thu, 27 Feb 2014 18:30:12 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id C882A20125 for ; Thu, 27 Feb 2014 18:30:10 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 893D2FB8B4; Thu, 27 Feb 2014 10:30:08 -0800 (PST) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTP id 7BD0BFB8B4 for ; Thu, 27 Feb 2014 10:30:06 -0800 (PST) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga102.jf.intel.com with ESMTP; 27 Feb 2014 10:25:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.97,556,1389772800"; d="scan'208";a="491055719" Received: from ironside.jf.intel.com ([10.7.197.217]) by orsmga002.jf.intel.com with ESMTP; 27 Feb 2014 10:30:05 -0800 From: Ben Widawsky To: Intel GFX Date: Thu, 27 Feb 2014 10:30:02 -0800 Message-Id: <1393525802-978-1-git-send-email-benjamin.widawsky@intel.com> X-Mailer: git-send-email 1.9.0 Cc: Ben Widawsky , Ben Widawsky Subject: [Intel-gfx] [PATCH] drm/i915: Paranoia - get zeroed page table pages X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: intel-gfx-bounces@lists.freedesktop.org Errors-To: intel-gfx-bounces@lists.freedesktop.org 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 We normally clear the page tables as one of the first things during initialization. They are however wired up (and potentially valid) before we clear them. To prevent the GPU from doing anything we might later regret, simply get zeroed pages, which always mean invalid on all GENs. NOTE: that a similar paranoia could be applied to GGTT via making sure all entries are invalid ASAP. I think the extra work required to fix such a BIOS bug is unwarranted until proven necessary. Signed-off-by: Ben Widawsky --- drivers/gpu/drm/i915/i915_gem_gtt.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 0c27d8a..f94d39d 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -354,12 +354,13 @@ static struct page **__gen8_alloc_page_tables(void) struct page **pt_pages; int i; - pt_pages = kcalloc(GEN8_PDES_PER_PAGE, sizeof(struct page *), GFP_KERNEL); + pt_pages = kcalloc(GEN8_PDES_PER_PAGE, sizeof(struct page *), + GFP_KERNEL | __GFP_ZERO); if (!pt_pages) return ERR_PTR(-ENOMEM); for (i = 0; i < GEN8_PDES_PER_PAGE; i++) { - pt_pages[i] = alloc_page(GFP_KERNEL); + pt_pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO); if (!pt_pages[i]) goto bail; } @@ -410,7 +411,7 @@ static int gen8_ppgtt_allocate_dma(struct i915_hw_ppgtt *ppgtt) for (i = 0; i < ppgtt->num_pd_pages; i++) { ppgtt->gen8_pt_dma_addr[i] = kcalloc(GEN8_PDES_PER_PAGE, sizeof(dma_addr_t), - GFP_KERNEL); + GFP_KERNEL | __GFP_ZERO); if (!ppgtt->gen8_pt_dma_addr[i]) return -ENOMEM; } @@ -421,7 +422,8 @@ static int gen8_ppgtt_allocate_dma(struct i915_hw_ppgtt *ppgtt) static int gen8_ppgtt_allocate_page_directories(struct i915_hw_ppgtt *ppgtt, const int max_pdp) { - ppgtt->pd_pages = alloc_pages(GFP_KERNEL, get_order(max_pdp << PAGE_SHIFT)); + ppgtt->pd_pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, + get_order(max_pdp << PAGE_SHIFT)); if (!ppgtt->pd_pages) return -ENOMEM; @@ -1015,13 +1017,13 @@ static int gen6_ppgtt_allocate_page_tables(struct i915_hw_ppgtt *ppgtt) int i; ppgtt->pt_pages = kcalloc(ppgtt->num_pd_entries, sizeof(struct page *), - GFP_KERNEL); + GFP_KERNEL | __GFP_ZERO); if (!ppgtt->pt_pages) return -ENOMEM; for (i = 0; i < ppgtt->num_pd_entries; i++) { - ppgtt->pt_pages[i] = alloc_page(GFP_KERNEL); + ppgtt->pt_pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO); if (!ppgtt->pt_pages[i]) { gen6_ppgtt_free(ppgtt); return -ENOMEM; @@ -1046,7 +1048,7 @@ static int gen6_ppgtt_alloc(struct i915_hw_ppgtt *ppgtt) } ppgtt->pt_dma_addr = kcalloc(ppgtt->num_pd_entries, sizeof(dma_addr_t), - GFP_KERNEL); + GFP_KERNEL | __GFP_ZERO); if (!ppgtt->pt_dma_addr) { drm_mm_remove_node(&ppgtt->node); gen6_ppgtt_free(ppgtt);