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=-8.6 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 75D75C31E46 for ; Wed, 12 Jun 2019 15:20:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B2A1D20874 for ; Wed, 12 Jun 2019 15:20:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2501936AbfFLPU0 (ORCPT ); Wed, 12 Jun 2019 11:20:26 -0400 Received: from pio-pvt-msa1.bahnhof.se ([79.136.2.40]:45712 "EHLO pio-pvt-msa1.bahnhof.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2439831AbfFLPUZ (ORCPT ); Wed, 12 Jun 2019 11:20:25 -0400 Received: from localhost (localhost [127.0.0.1]) by pio-pvt-msa1.bahnhof.se (Postfix) with ESMTP id 319213FBA1; Wed, 12 Jun 2019 17:20:23 +0200 (CEST) Authentication-Results: pio-pvt-msa1.bahnhof.se; dkim=pass (1024-bit key; unprotected) header.d=vmwopensource.org header.i=@vmwopensource.org header.b=ekS/pgbX; 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 sEhuZLDHL30M; Wed, 12 Jun 2019 17:20:10 +0200 (CEST) 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 A46F13F6C5; Wed, 12 Jun 2019 17:20:10 +0200 (CEST) Received: from localhost.localdomain.localdomain (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) by mail1.shipmail.org (Postfix) with ESMTPSA id 1D51C361DE3; Wed, 12 Jun 2019 17:20:10 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=vmwopensource.org; s=mail; t=1560352810; bh=jRi3wqSyWiOoYw5+545jNe9cwUPEy2pgjZ2pNofDdJw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ekS/pgbXi6YDmI0wYK34qRj/7OnSEOtpfc5dEybGFDLjISJUYiJeCl/gDI/7iFLXH jCZV/MEOB1XERjPCmRo0An+By8CwWloFMC7wjOH2PP0c9wGu03G0BMElOEEThol/KI liXVGbene0KPpjxZqIGHPcyb0tFchfkKd9DNtxlY= From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m=20=28VMware=29?= To: dri-devel@lists.freedesktop.org Cc: linux-graphics-maintainer@vmware.com, pv-drivers@vmware.com, linux-kernel@vger.kernel.org, hch@infradead.org, Thomas Hellstrom , =?UTF-8?q?Christian=20K=C3=B6nig?= Subject: [PATCH v6 5/9] drm/ttm: TTM fault handler helpers Date: Wed, 12 Jun 2019 17:19:46 +0200 Message-Id: <20190612151950.2870-6-thellstrom@vmwopensource.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190612151950.2870-1-thellstrom@vmwopensource.org> References: <20190612151950.2870-1-thellstrom@vmwopensource.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 With the vmwgfx dirty tracking, the default TTM fault handler is not completely sufficient (vmwgfx need to modify the vma->vm_flags member, and also needs to restrict the number of prefaults). We also want to replicate the new ttm_bo_vm_reserve() functionality So start turning the TTM vm code into helpers: ttm_bo_vm_fault_reserved() and ttm_bo_vm_reserve(), and provide a default TTM fault handler for other drivers to use. Cc: "Christian König" Signed-off-by: Thomas Hellstrom Reviewed-by: "Christian König" #v1 --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 175 +++++++++++++++++++------------- include/drm/ttm/ttm_bo_api.h | 10 ++ 2 files changed, 113 insertions(+), 72 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 196e13a0adad..2d9862fcf6fd 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -42,8 +42,6 @@ #include #include -#define TTM_BO_VM_NUM_PREFAULT 16 - static vm_fault_t ttm_bo_vm_fault_idle(struct ttm_buffer_object *bo, struct vm_fault *vmf) { @@ -106,31 +104,30 @@ static unsigned long ttm_bo_io_mem_pfn(struct ttm_buffer_object *bo, + page_offset; } -static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) +/** + * ttm_bo_vm_reserve - Reserve a buffer object in a retryable vm callback + * @bo: The buffer object + * @vmf: The fault structure handed to the callback + * + * vm callbacks like fault() and *_mkwrite() allow for the mm_sem to be dropped + * during long waits, and after the wait the callback will be restarted. This + * is to allow other threads using the same virtual memory space concurrent + * access to map(), unmap() completely unrelated buffer objects. TTM buffer + * object reservations sometimes wait for GPU and should therefore be + * considered long waits. This function reserves the buffer object interruptibly + * taking this into account. Starvation is avoided by the vm system not + * allowing too many repeated restarts. + * This function is intended to be used in customized fault() and _mkwrite() + * handlers. + * + * Return: + * 0 on success and the bo was reserved. + * VM_FAULT_RETRY if blocking wait. + * VM_FAULT_NOPAGE if blocking wait and retrying was not allowed. + */ +vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, + struct vm_fault *vmf) { - struct vm_area_struct *vma = vmf->vma; - struct ttm_buffer_object *bo = (struct ttm_buffer_object *) - vma->vm_private_data; - struct ttm_bo_device *bdev = bo->bdev; - unsigned long page_offset; - unsigned long page_last; - unsigned long pfn; - struct ttm_tt *ttm = NULL; - struct page *page; - int err; - int i; - vm_fault_t ret = VM_FAULT_NOPAGE; - unsigned long address = vmf->address; - struct ttm_mem_type_manager *man = - &bdev->man[bo->mem.mem_type]; - struct vm_area_struct cvma; - - /* - * Work around locking order reversal in fault / nopfn - * between mmap_sem and bo_reserve: Perform a trylock operation - * for reserve, and if it fails, retry the fault after waiting - * for the buffer to become unreserved. - */ if (unlikely(!reservation_object_trylock(bo->resv))) { if (vmf->flags & FAULT_FLAG_ALLOW_RETRY) { if (!(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { @@ -151,14 +148,55 @@ static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) return VM_FAULT_NOPAGE; } + return 0; +} +EXPORT_SYMBOL(ttm_bo_vm_reserve); + +/** + * ttm_bo_vm_fault_reserved - TTM fault helper + * @vmf: The struct vm_fault given as argument to the fault callback + * @prot: The page protection to be used for this memory area. + * @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. + * + * This function inserts one or more page table entries pointing to the + * memory backing the buffer object, and then returns a return code + * instructing the caller to retry the page access. + * + * Return: + * VM_FAULT_NOPAGE on success or pending signal + * VM_FAULT_SIGBUS on unspecified error + * VM_FAULT_OOM on out-of-memory + * VM_FAULT_RETRY if retryable wait + */ +vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, + pgprot_t prot, + pgoff_t num_prefault) +{ + struct vm_area_struct *vma = vmf->vma; + struct vm_area_struct cvma = *vma; + struct ttm_buffer_object *bo = (struct ttm_buffer_object *) + vma->vm_private_data; + struct ttm_bo_device *bdev = bo->bdev; + unsigned long page_offset; + unsigned long page_last; + unsigned long pfn; + struct ttm_tt *ttm = NULL; + struct page *page; + int err; + pgoff_t i; + vm_fault_t ret = VM_FAULT_NOPAGE; + unsigned long address = vmf->address; + struct ttm_mem_type_manager *man = + &bdev->man[bo->mem.mem_type]; + /* * Refuse to fault imported pages. This should be handled * (if at all) by redirecting mmap to the exporter. */ - if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) { - ret = VM_FAULT_SIGBUS; - goto out_unlock; - } + if (bo->ttm && (bo->ttm->page_flags & TTM_PAGE_FLAG_SG)) + return VM_FAULT_SIGBUS; if (bdev->driver->fault_reserve_notify) { struct dma_fence *moving = dma_fence_get(bo->moving); @@ -169,11 +207,9 @@ static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) break; case -EBUSY: case -ERESTARTSYS: - ret = VM_FAULT_NOPAGE; - goto out_unlock; + return VM_FAULT_NOPAGE; default: - ret = VM_FAULT_SIGBUS; - goto out_unlock; + return VM_FAULT_SIGBUS; } if (bo->moving != moving) { @@ -189,26 +225,15 @@ static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) * move. */ ret = ttm_bo_vm_fault_idle(bo, vmf); - if (unlikely(ret != 0)) { - if (ret == VM_FAULT_RETRY && - !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) { - /* The BO has already been unreserved. */ - return ret; - } - - goto out_unlock; - } + if (unlikely(ret != 0)) + return ret; err = ttm_mem_io_lock(man, true); - if (unlikely(err != 0)) { - ret = VM_FAULT_NOPAGE; - goto out_unlock; - } + if (unlikely(err != 0)) + return VM_FAULT_NOPAGE; err = ttm_mem_io_reserve_vm(bo); - if (unlikely(err != 0)) { - ret = VM_FAULT_SIGBUS; - goto out_io_unlock; - } + if (unlikely(err != 0)) + return VM_FAULT_SIGBUS; page_offset = ((address - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff - drm_vma_node_start(&bo->vma_node); @@ -220,18 +245,8 @@ static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) goto out_io_unlock; } - /* - * Make a local vma copy to modify the page_prot member - * and vm_flags if necessary. The vma parameter is protected - * by mmap_sem in write mode. - */ - cvma = *vma; - cvma.vm_page_prot = vm_get_page_prot(cvma.vm_flags); - - if (bo->mem.bus.is_iomem) { - cvma.vm_page_prot = ttm_io_prot(bo->mem.placement, - cvma.vm_page_prot); - } else { + cvma.vm_page_prot = ttm_io_prot(bo->mem.placement, prot); + if (!bo->mem.bus.is_iomem) { struct ttm_operation_ctx ctx = { .interruptible = false, .no_wait_gpu = false, @@ -240,24 +255,21 @@ static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) }; ttm = bo->ttm; - cvma.vm_page_prot = ttm_io_prot(bo->mem.placement, - cvma.vm_page_prot); - - /* Allocate all page at once, most common usage */ - if (ttm_tt_populate(ttm, &ctx)) { + if (ttm_tt_populate(bo->ttm, &ctx)) { ret = VM_FAULT_OOM; goto out_io_unlock; } + } else { + /* Iomem should not be marked encrypted */ + cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); } /* * Speculatively prefault a number of pages. Only error on * first page. */ - for (i = 0; i < TTM_BO_VM_NUM_PREFAULT; ++i) { + for (i = 0; i < num_prefault; ++i) { if (bo->mem.bus.is_iomem) { - /* Iomem should not be marked encrypted */ - cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot); pfn = ttm_bo_io_mem_pfn(bo, page_offset); } else { page = ttm->pages[page_offset]; @@ -295,7 +307,26 @@ static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) ret = VM_FAULT_NOPAGE; out_io_unlock: ttm_mem_io_unlock(man); -out_unlock: + return ret; +} +EXPORT_SYMBOL(ttm_bo_vm_fault_reserved); + +static vm_fault_t ttm_bo_vm_fault(struct vm_fault *vmf) +{ + struct vm_area_struct *vma = vmf->vma; + pgprot_t prot; + struct ttm_buffer_object *bo = vma->vm_private_data; + vm_fault_t ret; + + 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, TTM_BO_VM_NUM_PREFAULT); + if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT)) + return ret; + reservation_object_unlock(bo->resv); return ret; } diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h index 49d9cdfc58f2..435d02f719a8 100644 --- a/include/drm/ttm/ttm_bo_api.h +++ b/include/drm/ttm/ttm_bo_api.h @@ -768,4 +768,14 @@ int ttm_bo_swapout(struct ttm_bo_global *glob, struct ttm_operation_ctx *ctx); void ttm_bo_swapout_all(struct ttm_bo_device *bdev); int ttm_bo_wait_unreserved(struct ttm_buffer_object *bo); + +/* Default number of pre-faulted pages in the TTM fault handler */ +#define TTM_BO_VM_NUM_PREFAULT 16 + +vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, + struct vm_fault *vmf); + +vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, + pgprot_t prot, + pgoff_t num_prefault); #endif -- 2.20.1