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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F1A8C433F5 for ; Mon, 7 Mar 2022 10:11:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234180AbiCGKMh (ORCPT ); Mon, 7 Mar 2022 05:12:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50434 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S242307AbiCGKLY (ORCPT ); Mon, 7 Mar 2022 05:11:24 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E7A277AB9; Mon, 7 Mar 2022 01:54:52 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 74591B810BC; Mon, 7 Mar 2022 09:54:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D3F0C340E9; Mon, 7 Mar 2022 09:54:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646646884; bh=L9DEQvury+XcVkvoyTXNeEmq0xdtPhU4GEYWU4ZrIl0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mocm1wdAFOBxCjyxRtqI1Fy5eAES5Ng97nOVrKxxRvcRnwWaMg2hJo/xupvTWSKJH SKV5h0+j7XgYbSSd+hA3/1kjLgKZTR4+YGy63yWPb8h9lrc0E9eui+G4HBqunjf82X 46Az4QM+OlV2vTXWylxqOz1+NDAa65OVyj108pbo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Robin Murphy , Joerg Roedel , Sasha Levin Subject: [PATCH 5.16 124/186] iommu/amd: Simplify pagetable freeing Date: Mon, 7 Mar 2022 10:19:22 +0100 Message-Id: <20220307091657.547807028@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220307091654.092878898@linuxfoundation.org> References: <20220307091654.092878898@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Robin Murphy [ Upstream commit 6b3106e9ba2de7320a71291cedcefdcf1195ad58 ] For reasons unclear, pagetable freeing is an effectively recursive method implemented via an elaborate system of templated functions that turns out to account for 25% of the object file size. Implementing it using regular straightforward recursion makes the code simpler, and seems like a good thing to do before we work on it further. As part of that, also fix the types to avoid all the needless casting back and forth which just gets in the way. Signed-off-by: Robin Murphy Link: https://lore.kernel.org/r/d3d00c9f3fa0df4756b867072c201e6e82f9ce39.1639753638.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/amd/io_pgtable.c | 82 ++++++++++++++-------------------- 1 file changed, 34 insertions(+), 48 deletions(-) diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c index 182c93a43efd..4165e1372b6e 100644 --- a/drivers/iommu/amd/io_pgtable.c +++ b/drivers/iommu/amd/io_pgtable.c @@ -84,49 +84,45 @@ static void free_page_list(struct page *freelist) } } -static struct page *free_pt_page(unsigned long pt, struct page *freelist) +static struct page *free_pt_page(u64 *pt, struct page *freelist) { - struct page *p = virt_to_page((void *)pt); + struct page *p = virt_to_page(pt); p->freelist = freelist; return p; } -#define DEFINE_FREE_PT_FN(LVL, FN) \ -static struct page *free_pt_##LVL (unsigned long __pt, struct page *freelist) \ -{ \ - unsigned long p; \ - u64 *pt; \ - int i; \ - \ - pt = (u64 *)__pt; \ - \ - for (i = 0; i < 512; ++i) { \ - /* PTE present? */ \ - if (!IOMMU_PTE_PRESENT(pt[i])) \ - continue; \ - \ - /* Large PTE? */ \ - if (PM_PTE_LEVEL(pt[i]) == 0 || \ - PM_PTE_LEVEL(pt[i]) == 7) \ - continue; \ - \ - p = (unsigned long)IOMMU_PTE_PAGE(pt[i]); \ - freelist = FN(p, freelist); \ - } \ - \ - return free_pt_page((unsigned long)pt, freelist); \ -} +static struct page *free_pt_lvl(u64 *pt, struct page *freelist, int lvl) +{ + u64 *p; + int i; + + for (i = 0; i < 512; ++i) { + /* PTE present? */ + if (!IOMMU_PTE_PRESENT(pt[i])) + continue; -DEFINE_FREE_PT_FN(l2, free_pt_page) -DEFINE_FREE_PT_FN(l3, free_pt_l2) -DEFINE_FREE_PT_FN(l4, free_pt_l3) -DEFINE_FREE_PT_FN(l5, free_pt_l4) -DEFINE_FREE_PT_FN(l6, free_pt_l5) + /* Large PTE? */ + if (PM_PTE_LEVEL(pt[i]) == 0 || + PM_PTE_LEVEL(pt[i]) == 7) + continue; -static struct page *free_sub_pt(unsigned long root, int mode, - struct page *freelist) + /* + * Free the next level. No need to look at l1 tables here since + * they can only contain leaf PTEs; just free them directly. + */ + p = IOMMU_PTE_PAGE(pt[i]); + if (lvl > 2) + freelist = free_pt_lvl(p, freelist, lvl - 1); + else + freelist = free_pt_page(p, freelist); + } + + return free_pt_page(pt, freelist); +} + +static struct page *free_sub_pt(u64 *root, int mode, struct page *freelist) { switch (mode) { case PAGE_MODE_NONE: @@ -136,19 +132,11 @@ static struct page *free_sub_pt(unsigned long root, int mode, freelist = free_pt_page(root, freelist); break; case PAGE_MODE_2_LEVEL: - freelist = free_pt_l2(root, freelist); - break; case PAGE_MODE_3_LEVEL: - freelist = free_pt_l3(root, freelist); - break; case PAGE_MODE_4_LEVEL: - freelist = free_pt_l4(root, freelist); - break; case PAGE_MODE_5_LEVEL: - freelist = free_pt_l5(root, freelist); - break; case PAGE_MODE_6_LEVEL: - freelist = free_pt_l6(root, freelist); + free_pt_lvl(root, freelist, mode); break; default: BUG(); @@ -364,7 +352,7 @@ static u64 *fetch_pte(struct amd_io_pgtable *pgtable, static struct page *free_clear_pte(u64 *pte, u64 pteval, struct page *freelist) { - unsigned long pt; + u64 *pt; int mode; while (cmpxchg64(pte, pteval, 0) != pteval) { @@ -375,7 +363,7 @@ static struct page *free_clear_pte(u64 *pte, u64 pteval, struct page *freelist) if (!IOMMU_PTE_PRESENT(pteval)) return freelist; - pt = (unsigned long)IOMMU_PTE_PAGE(pteval); + pt = IOMMU_PTE_PAGE(pteval); mode = IOMMU_PTE_MODE(pteval); return free_sub_pt(pt, mode, freelist); @@ -512,7 +500,6 @@ static void v1_free_pgtable(struct io_pgtable *iop) struct amd_io_pgtable *pgtable = container_of(iop, struct amd_io_pgtable, iop); struct protection_domain *dom; struct page *freelist = NULL; - unsigned long root; if (pgtable->mode == PAGE_MODE_NONE) return; @@ -529,8 +516,7 @@ static void v1_free_pgtable(struct io_pgtable *iop) BUG_ON(pgtable->mode < PAGE_MODE_NONE || pgtable->mode > PAGE_MODE_6_LEVEL); - root = (unsigned long)pgtable->root; - freelist = free_sub_pt(root, pgtable->mode, freelist); + freelist = free_sub_pt(pgtable->root, pgtable->mode, freelist); free_page_list(freelist); } -- 2.34.1