From patchwork Wed Dec 8 10:20:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ramalingam C X-Patchwork-Id: 12664011 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1DE6EC433F5 for ; Wed, 8 Dec 2021 10:21:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 12EB66F51C; Wed, 8 Dec 2021 10:21:04 +0000 (UTC) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7D8DD6F510; Wed, 8 Dec 2021 10:21:02 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10191"; a="261878376" X-IronPort-AV: E=Sophos;i="5.87,297,1631602800"; d="scan'208";a="261878376" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2021 02:20:53 -0800 X-IronPort-AV: E=Sophos;i="5.87,297,1631602800"; d="scan'208";a="679842488" Received: from ramaling-i9x.iind.intel.com ([10.99.66.205]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2021 02:20:50 -0800 From: Ramalingam C To: intel-gfx , dri-devel Subject: [PATCH 1/3] drm/i915: Sanitycheck device iomem on probe Date: Wed, 8 Dec 2021 15:50:29 +0530 Message-Id: <20211208102031.4397-2-ramalingam.c@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20211208102031.4397-1-ramalingam.c@intel.com> References: <20211208102031.4397-1-ramalingam.c@intel.com> MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andi , Chris Wilson , CQ Tang , Hellstrom Thomas , Matthew Auld Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Chris Wilson As we setup the memory regions for the device, give each a quick test to verify that we can read and write to the full iomem range. This ensures that our physical addressing for the device's memory is correct, and some reassurance that the memory is functional. Signed-off-by: Chris Wilson Cc: Matthew Auld Cc: CQ Tang Signed-off-by: Ramalingam C Reviewed-by: Matthew Auld --- drivers/gpu/drm/i915/intel_memory_region.c | 104 +++++++++++++++++++++ 1 file changed, 104 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c index b43121609e25..c53e07f1d0c0 100644 --- a/drivers/gpu/drm/i915/intel_memory_region.c +++ b/drivers/gpu/drm/i915/intel_memory_region.c @@ -3,6 +3,8 @@ * Copyright © 2019 Intel Corporation */ +#include + #include "intel_memory_region.h" #include "i915_drv.h" #include "i915_ttm_buddy_manager.h" @@ -29,6 +31,99 @@ static const struct { }, }; +static int __iopagetest(struct intel_memory_region *mem, + u8 __iomem *va, int pagesize, + u8 value, resource_size_t offset, + const void *caller) +{ + int byte = prandom_u32_max(pagesize); + u8 result[3]; + + memset_io(va, value, pagesize); /* or GPF! */ + wmb(); + + result[0] = ioread8(va); + result[1] = ioread8(va + byte); + result[2] = ioread8(va + pagesize - 1); + if (memchr_inv(result, value, sizeof(result))) { + dev_err(mem->i915->drm.dev, + "Failed to read back from memory region:%pR at [%pa + %pa] for %ps; wrote %x, read (%x, %x, %x)\n", + &mem->region, &mem->io_start, &offset, caller, + value, result[0], result[1], result[2]); + return -EINVAL; + } + + return 0; +} + +static int iopagetest(struct intel_memory_region *mem, + resource_size_t offset, + const void *caller) +{ + const u8 val[] = { 0x0, 0xa5, 0xc3, 0xf0 }; + void __iomem *va; + int err; + int i; + + va = ioremap_wc(mem->io_start + offset, PAGE_SIZE); + if (!va) { + dev_err(mem->i915->drm.dev, + "Failed to ioremap memory region [%pa + %px] for %ps\n", + &mem->io_start, &offset, caller); + return -EFAULT; + } + + for (i = 0; i < ARRAY_SIZE(val); i++) { + err = __iopagetest(mem, va, PAGE_SIZE, val[i], offset, caller); + if (err) + break; + + err = __iopagetest(mem, va, PAGE_SIZE, ~val[i], offset, caller); + if (err) + break; + } + + iounmap(va); + return err; +} + +static resource_size_t random_page(resource_size_t last) +{ + /* Limited to low 44b (16TiB), but should suffice for a spot check */ + return prandom_u32_max(last >> PAGE_SHIFT) << PAGE_SHIFT; +} + +static int iomemtest(struct intel_memory_region *mem, const void *caller) +{ + resource_size_t last = resource_size(&mem->region) - PAGE_SIZE; + int err; + + /* + * Quick test to check read/write access to the iomap (backing store). + * + * Write a byte, read it back. If the iomapping fails, we expect + * a GPF preventing further execution. If the backing store does not + * exist, the read back will return garbage. We check a couple of pages, + * the first and last of the specified region to confirm the backing + * store + iomap does cover the entire memory region; and we check + * a random offset within as a quick spot check for bad memory. + */ + + err = iopagetest(mem, 0, caller); + if (err) + return err; + + err = iopagetest(mem, last, caller); + if (err) + return err; + + err = iopagetest(mem, random_page(last), caller); + if (err) + return err; + + return 0; +} + struct intel_memory_region * intel_memory_region_lookup(struct drm_i915_private *i915, u16 class, u16 instance) @@ -126,8 +221,17 @@ intel_memory_region_create(struct drm_i915_private *i915, goto err_free; } + if (io_start && IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) { + err = iomemtest(mem, (void *)_RET_IP_); + if (err) + goto err_release; + } + return mem; +err_release: + if (mem->ops->release) + mem->ops->release(mem); err_free: kfree(mem); return ERR_PTR(err);