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=-9.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 BFBD6C11D09 for ; Thu, 20 Feb 2020 12:27:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8479524656 for ; Thu, 20 Feb 2020 12:27:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=shipmail.org header.i=@shipmail.org header.b="JfwrQNMC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728074AbgBTM1o (ORCPT ); Thu, 20 Feb 2020 07:27:44 -0500 Received: from pio-pvt-msa1.bahnhof.se ([79.136.2.40]:33866 "EHLO pio-pvt-msa1.bahnhof.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727709AbgBTM1m (ORCPT ); Thu, 20 Feb 2020 07:27:42 -0500 Received: from localhost (localhost [127.0.0.1]) by pio-pvt-msa1.bahnhof.se (Postfix) with ESMTP id AF6F53F5BB; Thu, 20 Feb 2020 13:27:39 +0100 (CET) Authentication-Results: pio-pvt-msa1.bahnhof.se; dkim=pass (1024-bit key; unprotected) header.d=shipmail.org header.i=@shipmail.org header.b="JfwrQNMC"; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at bahnhof.se Received: from pio-pvt-msa1.bahnhof.se ([127.0.0.1]) by localhost (pio-pvt-msa1.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 1DV4f1o14L1h; Thu, 20 Feb 2020 13:27:38 +0100 (CET) Received: from mail1.shipmail.org (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) (Authenticated sender: mb878879) by pio-pvt-msa1.bahnhof.se (Postfix) with ESMTPA id 1D4083F5AE; Thu, 20 Feb 2020 13:27:37 +0100 (CET) Received: from localhost.localdomain.localdomain (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) by mail1.shipmail.org (Postfix) with ESMTPSA id D0FF3360487; Thu, 20 Feb 2020 13:27:34 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=shipmail.org; s=mail; t=1582201654; bh=YWEV2L/GcJ/BB131ReqWiiuK/xyWwF22eft0YAMzYMA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JfwrQNMCDN+22NaFkpWBESRI892OXgEFrVtj+8Hw+eVw1OS0d9AlQSby79XL964Ay RnFqaE18DlM/jO+vH/mxbvn+dw2tXcOE+qprpLk4TO24ODqgFQvGIv8wUSG9sYz313 SVrWF58WcMfyisPRjpMGtl/Vmoy/jHg7ZNpQ4tzI= From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m=20=28VMware=29?= To: linux-mm@kvack.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Cc: pv-drivers@vmware.com, linux-graphics-maintainer@vmware.com, Thomas Hellstrom , Andrew Morton , Michal Hocko , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , Ralph Campbell , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , =?UTF-8?q?Christian=20K=C3=B6nig?= , Dan Williams , Roland Scheidegger Subject: [PATCH v4 5/9] drm/ttm, drm/vmwgfx: Support huge TTM pagefaults Date: Thu, 20 Feb 2020 13:27:15 +0100 Message-Id: <20200220122719.4302-6-thomas_os@shipmail.org> X-Mailer: git-send-email 2.21.1 In-Reply-To: <20200220122719.4302-1-thomas_os@shipmail.org> References: <20200220122719.4302-1-thomas_os@shipmail.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Hellstrom Support huge (PMD-size and PUD-size) page-table entries by providing a huge_fault() callback. We still support private mappings and write-notify by splitting the huge page-table entries on write-access. Note that for huge page-faults to occur, either the kernel needs to be compiled with trans-huge-pages always enabled, or the kernel needs to be compiled with trans-huge-pages enabled using madvise, and the user-space app needs to call madvise() to enable trans-huge pages on a per-mapping basis. Furthermore huge page-faults will not succeed unless buffer objects and user-space addresses are aligned on huge page size boundaries. Cc: Andrew Morton Cc: Michal Hocko Cc: "Matthew Wilcox (Oracle)" Cc: "Kirill A. Shutemov" Cc: Ralph Campbell Cc: "Jérôme Glisse" Cc: "Christian König" Cc: Dan Williams Signed-off-by: Thomas Hellstrom Reviewed-by: Roland Scheidegger Reviewed-by: Christian König --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 161 ++++++++++++++++++++- drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c | 2 +- include/drm/ttm/ttm_bo_api.h | 3 +- 3 files changed, 161 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 389128b8c4dd..0af14835504c 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -156,6 +156,89 @@ vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, } EXPORT_SYMBOL(ttm_bo_vm_reserve); +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +/** + * ttm_bo_vm_insert_huge - Insert a pfn for PUD or PMD faults + * @vmf: Fault data + * @bo: The buffer object + * @page_offset: Page offset from bo start + * @fault_page_size: The size of the fault in pages. + * @pgprot: The page protections. + * Does additional checking whether it's possible to insert a PUD or PMD + * pfn and performs the insertion. + * + * Return: VM_FAULT_NOPAGE on successful insertion, VM_FAULT_FALLBACK if + * a huge fault was not possible, or on insertion error. + */ +static vm_fault_t ttm_bo_vm_insert_huge(struct vm_fault *vmf, + struct ttm_buffer_object *bo, + pgoff_t page_offset, + pgoff_t fault_page_size, + pgprot_t pgprot) +{ + pgoff_t i; + vm_fault_t ret; + unsigned long pfn; + pfn_t pfnt; + struct ttm_tt *ttm = bo->ttm; + bool write = vmf->flags & FAULT_FLAG_WRITE; + + /* Fault should not cross bo boundary. */ + page_offset &= ~(fault_page_size - 1); + if (page_offset + fault_page_size > bo->num_pages) + goto out_fallback; + + if (bo->mem.bus.is_iomem) + pfn = ttm_bo_io_mem_pfn(bo, page_offset); + else + pfn = page_to_pfn(ttm->pages[page_offset]); + + /* pfn must be fault_page_size aligned. */ + if ((pfn & (fault_page_size - 1)) != 0) + goto out_fallback; + + /* Check that memory is contiguous. */ + if (!bo->mem.bus.is_iomem) { + for (i = 1; i < fault_page_size; ++i) { + if (page_to_pfn(ttm->pages[page_offset + i]) != pfn + i) + goto out_fallback; + } + } else if (bo->bdev->driver->io_mem_pfn) { + for (i = 1; i < fault_page_size; ++i) { + if (ttm_bo_io_mem_pfn(bo, page_offset + i) != pfn + i) + goto out_fallback; + } + } + + pfnt = __pfn_to_pfn_t(pfn, PFN_DEV); + if (fault_page_size == (HPAGE_PMD_SIZE >> PAGE_SHIFT)) + ret = vmf_insert_pfn_pmd_prot(vmf, pfnt, pgprot, write); +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD + else if (fault_page_size == (HPAGE_PUD_SIZE >> PAGE_SHIFT)) + ret = vmf_insert_pfn_pud_prot(vmf, pfnt, pgprot, write); +#endif + else + WARN_ON_ONCE(ret = VM_FAULT_FALLBACK); + + if (ret != VM_FAULT_NOPAGE) + goto out_fallback; + + return VM_FAULT_NOPAGE; +out_fallback: + count_vm_event(THP_FAULT_FALLBACK); + return VM_FAULT_FALLBACK; +} +#else +static vm_fault_t ttm_bo_vm_insert_huge(struct vm_fault *vmf, + struct ttm_buffer_object *bo, + pgoff_t page_offset, + pgoff_t fault_page_size, + pgprot_t pgprot) +{ + return VM_FAULT_FALLBACK; +} +#endif + /** * ttm_bo_vm_fault_reserved - TTM fault helper * @vmf: The struct vm_fault given as argument to the fault callback @@ -163,6 +246,7 @@ EXPORT_SYMBOL(ttm_bo_vm_reserve); * @num_prefault: Maximum number of prefault pages. The caller may want to * specify this based on madvice settings and the size of the GPU object * backed by the memory. + * @fault_page_size: The size of the fault in pages. * * This function inserts one or more page table entries pointing to the * memory backing the buffer object, and then returns a return code @@ -176,7 +260,8 @@ EXPORT_SYMBOL(ttm_bo_vm_reserve); */ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, pgprot_t prot, - pgoff_t num_prefault) + pgoff_t num_prefault, + pgoff_t fault_page_size) { struct vm_area_struct *vma = vmf->vma; struct ttm_buffer_object *bo = vma->vm_private_data; @@ -268,6 +353,13 @@ vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, prot = pgprot_decrypted(prot); } + /* We don't prefault on huge faults. Yet. */ + if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && fault_page_size != 1) { + ret = ttm_bo_vm_insert_huge(vmf, bo, page_offset, + fault_page_size, prot); + goto out_io_unlock; + } + /* * Speculatively prefault a number of pages. Only error on * first page. @@ -334,7 +426,7 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) return ret; prot = vma->vm_page_prot; - ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT); + ret = ttm_bo_vm_fault_reserved(vmf, prot, TTM_BO_VM_NUM_PREFAULT, 1); if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) return ret; @@ -344,6 +436,66 @@ vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) } EXPORT_SYMBOL(ttm_bo_vm_fault); +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +/** + * ttm_pgprot_is_wrprotecting - Is a page protection value write-protecting? + * @prot: The page protection value + * + * Return: true if @prot is write-protecting. false otherwise. + */ +static bool ttm_pgprot_is_wrprotecting(pgprot_t prot) +{ + /* + * This is meant to say "pgprot_wrprotect(prot) == prot" in a generic + * way. Unfortunately there is no generic pgprot_wrprotect. + */ + return pte_val(pte_wrprotect(__pte(pgprot_val(prot)))) == + pgprot_val(prot); +} + +static vm_fault_t ttm_bo_vm_huge_fault(struct vm_fault *vmf, + enum page_entry_size pe_size) +{ + struct vm_area_struct *vma = vmf->vma; + pgprot_t prot; + struct ttm_buffer_object *bo = vma->vm_private_data; + vm_fault_t ret; + pgoff_t fault_page_size = 0; + bool write = vmf->flags & FAULT_FLAG_WRITE; + + switch (pe_size) { + case PE_SIZE_PMD: + fault_page_size = HPAGE_PMD_SIZE >> PAGE_SHIFT; + break; +#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD + case PE_SIZE_PUD: + fault_page_size = HPAGE_PUD_SIZE >> PAGE_SHIFT; + break; +#endif + default: + WARN_ON_ONCE(1); + return VM_FAULT_FALLBACK; + } + + /* Fallback on write dirty-tracking or COW */ + if (write && ttm_pgprot_is_wrprotecting(vma->vm_page_prot)) + return VM_FAULT_FALLBACK; + + ret = ttm_bo_vm_reserve(bo, vmf); + if (ret) + return ret; + + prot = vm_get_page_prot(vma->vm_flags); + ret = ttm_bo_vm_fault_reserved(vmf, prot, 1, fault_page_size); + if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) + return ret; + + dma_resv_unlock(bo->base.resv); + + return ret; +} +#endif + void ttm_bo_vm_open(struct vm_area_struct *vma) { struct ttm_buffer_object *bo = vma->vm_private_data; @@ -445,7 +597,10 @@ static const struct vm_operations_struct ttm_bo_vm_ops = { .fault = ttm_bo_vm_fault, .open = ttm_bo_vm_open, .close = ttm_bo_vm_close, - .access = ttm_bo_vm_access + .access = ttm_bo_vm_access, +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + .huge_fault = ttm_bo_vm_huge_fault, +#endif }; static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev, diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c index f07aa857587c..17a5dca7b921 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_page_dirty.c @@ -477,7 +477,7 @@ vm_fault_t vmw_bo_vm_fault(struct vm_fault *vmf) else prot = vm_get_page_prot(vma->vm_flags); - ret = ttm_bo_vm_fault_reserved(vmf, prot, num_prefault); + ret = ttm_bo_vm_fault_reserved(vmf, prot, num_prefault, 1); if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) return ret; diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 66ca49db9633..4fc90d53aa15 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -732,7 +732,8 @@ vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, pgprot_t prot, - pgoff_t num_prefault); + pgoff_t num_prefault, + pgoff_t fault_page_size); vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf); -- 2.21.1