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=-13.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 BE489C43458 for ; Tue, 14 Jul 2020 12:40:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A0C0B22472 for ; Tue, 14 Jul 2020 12:40:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728553AbgGNMkJ (ORCPT ); Tue, 14 Jul 2020 08:40:09 -0400 Received: from mx2.suse.de ([195.135.220.15]:54834 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728478AbgGNMkC (ORCPT ); Tue, 14 Jul 2020 08:40:02 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 6931AB036; Tue, 14 Jul 2020 12:40:03 +0000 (UTC) From: Nicolas Saenz Julienne To: hch@lst.de, linux-kernel@vger.kernel.org, Marek Szyprowski , Robin Murphy , David Rientjes Cc: linux-rpi-kernel@lists.infradead.org, jeremy.linton@arm.com, Nicolas Saenz Julienne , iommu@lists.linux-foundation.org Subject: [PATCH v2 4/4] dma-pool: Make sure atomic pool suits device Date: Tue, 14 Jul 2020 14:39:28 +0200 Message-Id: <20200714123928.8581-5-nsaenzjulienne@suse.de> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200714123928.8581-1-nsaenzjulienne@suse.de> References: <20200714123928.8581-1-nsaenzjulienne@suse.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When allocating DMA memory from a pool, the core can only guess which atomic pool will fit a device's constraints. If it doesn't, get a safer atomic pool and try again. Fixes: c84dc6e68a1d ("dma-pool: add additional coherent pools to map to gfp mask") Reported-by: Jeremy Linton Suggested-by: Robin Murphy Signed-off-by: Nicolas Saenz Julienne --- Changes since v1: - Rebase to linus' master kernel/dma/pool.c | 57 ++++++++++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 20 deletions(-) diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c index 5b9eaa2b498d..d48d9acb585f 100644 --- a/kernel/dma/pool.c +++ b/kernel/dma/pool.c @@ -240,39 +240,56 @@ static inline struct gen_pool *dma_guess_pool(struct device *dev, void *dma_alloc_from_pool(struct device *dev, size_t size, struct page **ret_page, gfp_t flags) { - struct gen_pool *pool = dma_guess_pool(dev, NULL); - unsigned long val; + struct gen_pool *pool = NULL; + unsigned long val = 0; void *ptr = NULL; - - if (!pool) { - WARN(1, "%pGg atomic pool not initialised!\n", &flags); - return NULL; + phys_addr_t phys; + + while (1) { + pool = dma_guess_pool(dev, pool); + if (!pool) { + WARN(1, "Failed to get suitable pool for %s\n", + dev_name(dev)); + break; + } + + val = gen_pool_alloc(pool, size); + if (!val) + continue; + + phys = gen_pool_virt_to_phys(pool, val); + if (dma_coherent_ok(dev, phys, size)) + break; + + gen_pool_free(pool, val, size); + val = 0; } - val = gen_pool_alloc(pool, size); - if (likely(val)) { - phys_addr_t phys = gen_pool_virt_to_phys(pool, val); + if (val) { *ret_page = pfn_to_page(__phys_to_pfn(phys)); ptr = (void *)val; memset(ptr, 0, size); - } else { - WARN_ONCE(1, "DMA coherent pool depleted, increase size " - "(recommended min coherent_pool=%zuK)\n", - gen_pool_size(pool) >> 9); + + if (gen_pool_avail(pool) < atomic_pool_size) + schedule_work(&atomic_pool_work); } - if (gen_pool_avail(pool) < atomic_pool_size) - schedule_work(&atomic_pool_work); return ptr; } bool dma_free_from_pool(struct device *dev, void *start, size_t size) { - struct gen_pool *pool = dma_guess_pool(dev, NULL); + struct gen_pool *pool = NULL; - if (!pool || !gen_pool_has_addr(pool, (unsigned long)start, size)) - return false; - gen_pool_free(pool, (unsigned long)start, size); - return true; + while (1) { + pool = dma_guess_pool(dev, pool); + if (!pool) + return false; + + if (gen_pool_has_addr(pool, (unsigned long)start, size)) { + gen_pool_free(pool, (unsigned long)start, size); + return true; + } + } } -- 2.27.0