From patchwork Wed Dec 8 15:34:03 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Ramalingam C X-Patchwork-Id: 12664701 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 33B81C433FE for ; Wed, 8 Dec 2021 15:34:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id DAC457396A; Wed, 8 Dec 2021 15:34:41 +0000 (UTC) Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id 523D173965; Wed, 8 Dec 2021 15:34:39 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6200,9189,10192"; a="301234032" X-IronPort-AV: E=Sophos;i="5.88,189,1635231600"; d="scan'208";a="301234032" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 08 Dec 2021 07:34:27 -0800 X-IronPort-AV: E=Sophos;i="5.88,189,1635231600"; d="scan'208";a="679919207" 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 07:34:25 -0800 From: Ramalingam C To: intel-gfx , dri-devel Subject: [PATCH 2/3] drm/i915: Sanitycheck device iomem on probe Date: Wed, 8 Dec 2021 21:04:03 +0530 Message-Id: <20211208153404.27546-3-ramalingam.c@intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20211208153404.27546-1-ramalingam.c@intel.com> References: <20211208153404.27546-1-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: Matthew Auld , Andi Shyti , Chris Wilson 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. v2: wrapper for memtest [Chris] v3: Removed the unused ptr i915 [Chris] Signed-off-by: Chris Wilson Cc: Matthew Auld Signed-off-by: Ramalingam C Reviewed-by: Matthew Auld Reviewed-by: Andi Shyti --- drivers/gpu/drm/i915/intel_memory_region.c | 116 +++++++++++++++++++++ 1 file changed, 116 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_memory_region.c b/drivers/gpu/drm/i915/intel_memory_region.c index b43121609e25..458afc648772 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) @@ -90,6 +185,20 @@ void intel_memory_region_debug(struct intel_memory_region *mr, &mr->total, &mr->avail); } +static int intel_memory_region_memtest(struct intel_memory_region *mem, + void *caller) +{ + int err = 0; + + if (!mem->io_start) + return 0; + + if (IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)) + err = iomemtest(mem, caller); + + return err; +} + struct intel_memory_region * intel_memory_region_create(struct drm_i915_private *i915, resource_size_t start, @@ -126,8 +235,15 @@ intel_memory_region_create(struct drm_i915_private *i915, goto err_free; } + err = intel_memory_region_memtest(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);