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=-17.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,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 AA4FDC433E6 for ; Sun, 7 Feb 2021 16:04:01 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3F7D764DF6 for ; Sun, 7 Feb 2021 16:04:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F7D764DF6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=dyuMeCEgHp+Y6PzFSjjohIZh8jzKFgT5TQJeVzUIg8s=; b=E1YiEoqEo1ezQ6UiKYAIhUSdG Y68IpggNGKoWkCYWk73DNRE3Il5Qb/kIp2wetCs2kIhm6GcTWLzeAJIEtM5ImwPwJDj3ePGTRreDC pvhk6c+PHYU4j9i5JXqUQVwqBJWRlU8+65ZPGZbslxxvh3FUsf0yno/OqJ/x/nNi6CD+lTTyx4BQ8 wfJLqurp7IIIepfoPloLlTyCu5cuGll1/3uWITxpIKU8zsYiCumTdTZyh8NpeAKytRwOjlH3bFK5K kGZGS4C4ZxMTq69QDLSY17NOx9Wo2c1tVHJSB2ii7HhsOoSHxLUCd0BT+mm1KTbhjiKuRjnpvRb2j XUSEgo64A==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l8mXT-0004qM-E1; Sun, 07 Feb 2021 16:03:55 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1l8mXP-0004op-VA for linux-nvme@merlin.infradead.org; Sun, 07 Feb 2021 16:03:52 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=P2VjsEbMa6DUn4kH4ljL8IHLanLORae4Kn0TQUwBJwc=; b=G8BVZGDZU1zwnIL0427hAeTpsJ oy5PimlhiBe+6Cy4Sw9njhyTb2Cwfl923XAsxFVSWzyUiYBYmNP8AahaQ8G5Z9Posd02dfeeK7Qiy aRC6qTLBarABVsPwTYqrWuDTTebrc3USRRbfKMnDNhcYZrN+3mWYRfwXamVR6VRGAAo3+RizZ/v/O EkTMu7115BC5gXLeTXJczmWFng0qSzanNkY6x1DWCe5RCWmSY2bUrwIGcigRxB17o7VTM+4SCdmwy W6OPMDSZQh1LndAA0ZzSg/+V/l5GYCTIMyKqaZNbrTmJ42jU4rdPtGAilza+pDuY6k8xw5pJNbrxl 9103yklA==; Received: from [2001:4bb8:184:7d04:4590:5583:6cb7:77c7] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1l8mXN-004tOX-2k; Sun, 07 Feb 2021 16:03:50 +0000 From: Christoph Hellwig To: jxgao@google.com, gregkh@linuxfoundation.org Subject: [PATCH 6/9] swiotlb: refactor swiotlb_tbl_map_single Date: Sun, 7 Feb 2021 17:03:24 +0100 Message-Id: <20210207160327.2955490-7-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210207160327.2955490-1-hch@lst.de> References: <20210207160327.2955490-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: saravanak@google.com, konrad.wilk@oracle.com, marcorr@google.com, linux-nvme@lists.infradead.org, kbusch@kernel.org, iommu@lists.linux-foundation.org, erdemaktas@google.com, robin.murphy@arm.com, m.szyprowski@samsung.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Split out a bunch of a self-contained helpers to make the function easier to follow. Signed-off-by: Christoph Hellwig --- kernel/dma/swiotlb.c | 179 +++++++++++++++++++++---------------------- 1 file changed, 89 insertions(+), 90 deletions(-) diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index b38b1553c4663a..381c24ef1ac1d0 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -468,134 +468,133 @@ static void swiotlb_bounce(phys_addr_t orig_addr, phys_addr_t tlb_addr, } } -phys_addr_t swiotlb_tbl_map_single(struct device *hwdev, phys_addr_t orig_addr, - size_t mapping_size, size_t alloc_size, - enum dma_data_direction dir, unsigned long attrs) -{ - dma_addr_t tbl_dma_addr = phys_to_dma_unencrypted(hwdev, io_tlb_start); - unsigned long flags; - phys_addr_t tlb_addr; - unsigned int nslots, stride, index, wrap; - int i; - unsigned long mask; - unsigned long offset_slots; - unsigned long max_slots; - unsigned long tmp_io_tlb_used; - - if (no_iotlb_memory) - panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); - - if (mem_encrypt_active()) - pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n"); +#define slot_addr(start, idx) ((start) + ((idx) << IO_TLB_SHIFT)) - if (mapping_size > alloc_size) { - dev_warn_once(hwdev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)", - mapping_size, alloc_size); - return (phys_addr_t)DMA_MAPPING_ERROR; - } - - mask = dma_get_seg_boundary(hwdev); +/* + * Carefully handle integer overflow which can occur when boundary_mask == ~0UL. + */ +static inline unsigned long get_max_slots(unsigned long boundary_mask) +{ + if (boundary_mask == ~0UL) + return 1UL << (BITS_PER_LONG - IO_TLB_SHIFT); + return nr_slots(boundary_mask + 1); +} - tbl_dma_addr &= mask; +static unsigned int wrap_index(unsigned int index) +{ + if (index >= io_tlb_nslabs) + return 0; + return index; +} - offset_slots = nr_slots(tbl_dma_addr); +/* + * Find a suitable number of IO TLB entries size that will fit this request and + * allocate a buffer from that IO TLB pool. + */ +static int find_slots(struct device *dev, size_t alloc_size) +{ + unsigned long boundary_mask = dma_get_seg_boundary(dev); + dma_addr_t tbl_dma_addr = + phys_to_dma_unencrypted(dev, io_tlb_start) & boundary_mask; + unsigned int max_slots = get_max_slots(boundary_mask); + unsigned int nslots = nr_slots(alloc_size), stride = 1; + unsigned int index, wrap, count = 0, i; + unsigned long flags; - /* - * Carefully handle integer overflow which can occur when mask == ~0UL. - */ - max_slots = mask + 1 - ? nr_slots(mask + 1) - : 1UL << (BITS_PER_LONG - IO_TLB_SHIFT); + BUG_ON(!nslots); /* * For mappings greater than or equal to a page, we limit the stride * (and hence alignment) to a page size. */ - nslots = nr_slots(alloc_size); if (alloc_size >= PAGE_SIZE) - stride = (1 << (PAGE_SHIFT - IO_TLB_SHIFT)); - else - stride = 1; + stride <<= (PAGE_SHIFT - IO_TLB_SHIFT); - BUG_ON(!nslots); - - /* - * Find suitable number of IO TLB entries size that will fit this - * request and allocate a buffer from that IO TLB pool. - */ spin_lock_irqsave(&io_tlb_lock, flags); - if (unlikely(nslots > io_tlb_nslabs - io_tlb_used)) goto not_found; - index = ALIGN(io_tlb_index, stride); - if (index >= io_tlb_nslabs) - index = 0; - wrap = index; - + index = wrap = wrap_index(ALIGN(io_tlb_index, stride)); do { - while (iommu_is_span_boundary(index, nslots, offset_slots, - max_slots)) { - index += stride; - if (index >= io_tlb_nslabs) - index = 0; - if (index == wrap) - goto not_found; - } - /* * If we find a slot that indicates we have 'nslots' number of * contiguous buffers, we allocate the buffers from that slot * and mark the entries as '0' indicating unavailable. */ - if (io_tlb_list[index] >= nslots) { - int count = 0; - - for (i = index; i < (int) (index + nslots); i++) - io_tlb_list[i] = 0; - for (i = index - 1; - io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 && - io_tlb_list[i]; i--) - io_tlb_list[i] = ++count; - tlb_addr = io_tlb_start + (index << IO_TLB_SHIFT); - - /* - * Update the indices to avoid searching in the next - * round. - */ - io_tlb_index = ((index + nslots) < io_tlb_nslabs - ? (index + nslots) : 0); - - goto found; + if (!iommu_is_span_boundary(index, nslots, + nr_slots(tbl_dma_addr), + max_slots)) { + if (io_tlb_list[index] >= nslots) + goto found; } - index += stride; - if (index >= io_tlb_nslabs) - index = 0; + index = wrap_index(index + stride); } while (index != wrap); not_found: - tmp_io_tlb_used = io_tlb_used; - spin_unlock_irqrestore(&io_tlb_lock, flags); - if (!(attrs & DMA_ATTR_NO_WARN) && printk_ratelimit()) - dev_warn(hwdev, "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n", - alloc_size, io_tlb_nslabs, tmp_io_tlb_used); - return (phys_addr_t)DMA_MAPPING_ERROR; + return -1; + found: + for (i = index; i < index + nslots; i++) + io_tlb_list[i] = 0; + for (i = index - 1; + io_tlb_offset(i) != IO_TLB_SEGSIZE - 1 && + io_tlb_list[i]; i--) + io_tlb_list[i] = ++count; + + /* + * Update the indices to avoid searching in the next round. + */ + if (index + nslots < io_tlb_nslabs) + io_tlb_index = index + nslots; + else + io_tlb_index = 0; io_tlb_used += nslots; + spin_unlock_irqrestore(&io_tlb_lock, flags); + return index; +} + +phys_addr_t swiotlb_tbl_map_single(struct device *dev, phys_addr_t orig_addr, + size_t mapping_size, size_t alloc_size, + enum dma_data_direction dir, unsigned long attrs) +{ + unsigned int index, i; + phys_addr_t tlb_addr; + + if (no_iotlb_memory) + panic("Can not allocate SWIOTLB buffer earlier and can't now provide you with the DMA bounce buffer"); + + if (mem_encrypt_active()) + pr_warn_once("Memory encryption is active and system is using DMA bounce buffers\n"); + + if (mapping_size > alloc_size) { + dev_warn_once(dev, "Invalid sizes (mapping: %zd bytes, alloc: %zd bytes)", + mapping_size, alloc_size); + return (phys_addr_t)DMA_MAPPING_ERROR; + } + + index = find_slots(dev, alloc_size); + if (index == -1) { + if (!(attrs & DMA_ATTR_NO_WARN)) + dev_warn_ratelimited(dev, + "swiotlb buffer is full (sz: %zd bytes), total %lu (slots), used %lu (slots)\n", + alloc_size, io_tlb_nslabs, io_tlb_used); + return (phys_addr_t)DMA_MAPPING_ERROR; + } /* * Save away the mapping from the original address to the DMA address. * This is needed when we sync the memory. Then we sync the buffer if * needed. */ - for (i = 0; i < nslots; i++) - io_tlb_orig_addr[index+i] = orig_addr + (i << IO_TLB_SHIFT); + for (i = 0; i < nr_slots(alloc_size); i++) + io_tlb_orig_addr[index + i] = slot_addr(orig_addr, i); + + tlb_addr = slot_addr(io_tlb_start, index); if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) && (dir == DMA_TO_DEVICE || dir == DMA_BIDIRECTIONAL)) swiotlb_bounce(orig_addr, tlb_addr, mapping_size, DMA_TO_DEVICE); - return tlb_addr; } -- 2.29.2 _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme