From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 997DFC4363D for ; Fri, 25 Sep 2020 13:11:59 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 37FA222B2D for ; Fri, 25 Sep 2020 13:11:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 37FA222B2D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A46DC6B009E; Fri, 25 Sep 2020 09:11:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A1DF56B009F; Fri, 25 Sep 2020 09:11:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8BEFB6B00A0; Fri, 25 Sep 2020 09:11:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0043.hostedemail.com [216.40.44.43]) by kanga.kvack.org (Postfix) with ESMTP id 72ABC6B009E for ; Fri, 25 Sep 2020 09:11:58 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 306398249980 for ; Fri, 25 Sep 2020 13:11:58 +0000 (UTC) X-FDA: 77301621516.11.taste22_37025bc27167 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin11.hostedemail.com (Postfix) with ESMTP id 064A4180F8B80 for ; Fri, 25 Sep 2020 13:11:58 +0000 (UTC) X-HE-Tag: taste22_37025bc27167 X-Filterd-Recvd-Size: 9165 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by imf01.hostedemail.com (Postfix) with ESMTP for ; Fri, 25 Sep 2020 13:11:57 +0000 (UTC) IronPort-SDR: ZOfpidcxvMij7VSGxoNl220UJ76J1i6+2qhKSvmdplWpSeIwgjb3m2EwNhj8bUq5Mnuub8+vmG FqXyKBeGVK/A== X-IronPort-AV: E=McAfee;i="6000,8403,9754"; a="162418769" X-IronPort-AV: E=Sophos;i="5.77,302,1596524400"; d="scan'208";a="162418769" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2020 06:11:41 -0700 IronPort-SDR: Cx9GTgN932+B5kZwf5dsa5xKxL7N/hfSSwW0z4VmSrslkwicASqHt4X6SFa68TyEONbCGp1Y40 IRYR97di+wig== X-IronPort-AV: E=Sophos;i="5.77,302,1596524400"; d="scan'208";a="455828530" Received: from mlevy2-mobl.ger.corp.intel.com (HELO [10.251.176.131]) ([10.251.176.131]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Sep 2020 06:11:35 -0700 Subject: Re: [PATCH 08/11] drm/i915: use vmap in i915_gem_object_map To: Christoph Hellwig , Andrew Morton Cc: Peter Zijlstra , Boris Ostrovsky , Juergen Gross , Stefano Stabellini , Jani Nikula , Joonas Lahtinen , Chris Wilson , Matthew Auld , Rodrigo Vivi , Minchan Kim , Matthew Wilcox , Nitin Gupta , x86@kernel.org, xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-mm@kvack.org References: <20200924135853.875294-1-hch@lst.de> <20200924135853.875294-9-hch@lst.de> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <63e331f4-2283-b579-f9b1-795a73f80bb8@linux.intel.com> Date: Fri, 25 Sep 2020 14:11:32 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200924135853.875294-9-hch@lst.de> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 24/09/2020 14:58, Christoph Hellwig wrote: > i915_gem_object_map implements fairly low-level vmap functionality in > a driver. Split it into two helpers, one for remapping kernel memory > which can use vmap, and one for I/O memory that uses vmap_pfn. > > The only practical difference is that alloc_vm_area prefeaults the > vmalloc area PTEs, which doesn't seem to be required here for the > kernel memory case (and could be added to vmap using a flag if actually > required). > > Signed-off-by: Christoph Hellwig > --- > drivers/gpu/drm/i915/Kconfig | 1 + > drivers/gpu/drm/i915/gem/i915_gem_pages.c | 126 ++++++++++------------ > 2 files changed, 59 insertions(+), 68 deletions(-) > > diff --git a/drivers/gpu/drm/i915/Kconfig b/drivers/gpu/drm/i915/Kconfig > index 9afa5c4a6bf006..1e1cb245fca778 100644 > --- a/drivers/gpu/drm/i915/Kconfig > +++ b/drivers/gpu/drm/i915/Kconfig > @@ -25,6 +25,7 @@ config DRM_I915 > select CRC32 > select SND_HDA_I915 if SND_HDA_CORE > select CEC_CORE if CEC_NOTIFIER > + select VMAP_PFN > help > Choose this option if you have a system that has "Intel Graphics > Media Accelerator" or "HD Graphics" integrated graphics, > diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pages.c b/drivers/gpu/drm/i915/gem/i915_gem_pages.c > index 6550c0bc824ea2..b519417667eb4b 100644 > --- a/drivers/gpu/drm/i915/gem/i915_gem_pages.c > +++ b/drivers/gpu/drm/i915/gem/i915_gem_pages.c > @@ -232,34 +232,21 @@ int __i915_gem_object_put_pages(struct drm_i915_gem_object *obj) > return err; > } > > -static inline pte_t iomap_pte(resource_size_t base, > - dma_addr_t offset, > - pgprot_t prot) > -{ > - return pte_mkspecial(pfn_pte((base + offset) >> PAGE_SHIFT, prot)); > -} > - > /* The 'mapping' part of i915_gem_object_pin_map() below */ > -static void *i915_gem_object_map(struct drm_i915_gem_object *obj, > - enum i915_map_type type) > +static void *i915_gem_object_map_page(struct drm_i915_gem_object *obj, > + enum i915_map_type type) > { > - unsigned long n_pte = obj->base.size >> PAGE_SHIFT; > - struct sg_table *sgt = obj->mm.pages; > - pte_t *stack[32], **mem; > - struct vm_struct *area; > + unsigned long n_pages = obj->base.size >> PAGE_SHIFT, i; > + struct page *stack[32], **pages = stack, *page; > + struct sgt_iter iter; > pgprot_t pgprot; > + void *vaddr; > > - if (!i915_gem_object_has_struct_page(obj) && type != I915_MAP_WC) > - return NULL; > - > - if (GEM_WARN_ON(type == I915_MAP_WC && > - !static_cpu_has(X86_FEATURE_PAT))) > - return NULL; > - > - /* A single page can always be kmapped */ > - if (n_pte == 1 && type == I915_MAP_WB) { > - struct page *page = sg_page(sgt->sgl); > - > + switch (type) { > + default: > + MISSING_CASE(type); > + fallthrough; /* to use PAGE_KERNEL anyway */ > + case I915_MAP_WB: > /* > * On 32b, highmem using a finite set of indirect PTE (i.e. > * vmap) to provide virtual mappings of the high pages. > @@ -277,30 +264,8 @@ static void *i915_gem_object_map(struct drm_i915_gem_object *obj, > * So if the page is beyond the 32b boundary, make an explicit > * vmap. > */ > - if (!PageHighMem(page)) > - return page_address(page); > - } > - > - mem = stack; > - if (n_pte > ARRAY_SIZE(stack)) { > - /* Too big for stack -- allocate temporary array instead */ > - mem = kvmalloc_array(n_pte, sizeof(*mem), GFP_KERNEL); > - if (!mem) > - return NULL; > - } > - > - area = alloc_vm_area(obj->base.size, mem); > - if (!area) { > - if (mem != stack) > - kvfree(mem); > - return NULL; > - } > - > - switch (type) { > - default: > - MISSING_CASE(type); > - fallthrough; /* to use PAGE_KERNEL anyway */ > - case I915_MAP_WB: > + if (n_pages == 1 && !PageHighMem(sg_page(obj->mm.pages->sgl))) > + return page_address(sg_page(obj->mm.pages->sgl)); > pgprot = PAGE_KERNEL; > break; > case I915_MAP_WC: > @@ -308,30 +273,49 @@ static void *i915_gem_object_map(struct drm_i915_gem_object *obj, > break; > } > > - if (i915_gem_object_has_struct_page(obj)) { > - struct sgt_iter iter; > - struct page *page; > - pte_t **ptes = mem; > + if (n_pages > ARRAY_SIZE(stack)) { > + /* Too big for stack -- allocate temporary array instead */ > + pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL); > + if (!pages) > + return NULL; > + } > > - for_each_sgt_page(page, iter, sgt) > - **ptes++ = mk_pte(page, pgprot); > - } else { > - resource_size_t iomap; > - struct sgt_iter iter; > - pte_t **ptes = mem; > - dma_addr_t addr; > + i = 0; > + for_each_sgt_page(page, iter, obj->mm.pages) > + pages[i++] = page; > + vaddr = vmap(pages, n_pages, 0, pgprot); > + if (pages != stack) > + kvfree(pages); > + return vaddr; > +} > > - iomap = obj->mm.region->iomap.base; > - iomap -= obj->mm.region->region.start; > +static void *i915_gem_object_map_pfn(struct drm_i915_gem_object *obj, > + enum i915_map_type type) > +{ > + resource_size_t iomap = obj->mm.region->iomap.base - > + obj->mm.region->region.start; > + unsigned long n_pfn = obj->base.size >> PAGE_SHIFT; > + unsigned long stack[32], *pfns = stack, i; > + struct sgt_iter iter; > + dma_addr_t addr; > + void *vaddr; > + > + if (type != I915_MAP_WC) > + return NULL; > > - for_each_sgt_daddr(addr, iter, sgt) > - **ptes++ = iomap_pte(iomap, addr, pgprot); > + if (n_pfn > ARRAY_SIZE(stack)) { > + /* Too big for stack -- allocate temporary array instead */ > + pfns = kvmalloc_array(n_pfn, sizeof(*pfns), GFP_KERNEL); > + if (!pfns) > + return NULL; > } > > - if (mem != stack) > - kvfree(mem); > - > - return area->addr; > + for_each_sgt_daddr(addr, iter, obj->mm.pages) > + pfns[i++] = (iomap + addr) >> PAGE_SHIFT; > + vaddr = vmap_pfn(pfns, n_pfn, pgprot_writecombine(PAGE_KERNEL_IO)); > + if (pfns != stack) > + kvfree(pfns); > + return vaddr; > } > > /* get, pin, and map the pages of the object into kernel space */ > @@ -383,7 +367,13 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj, > } > > if (!ptr) { > - ptr = i915_gem_object_map(obj, type); > + if (GEM_WARN_ON(type == I915_MAP_WC && > + !static_cpu_has(X86_FEATURE_PAT))) > + ptr = NULL; > + else if (i915_gem_object_has_struct_page(obj)) > + ptr = i915_gem_object_map_page(obj, type); > + else > + ptr = i915_gem_object_map_pfn(obj, type); > if (!ptr) { > err = -ENOMEM; > goto err_unpin; > Reviewed-by: Tvrtko Ursulin Regards, Tvrtko