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 D4D0FC4332F for ; Tue, 23 Nov 2021 14:11:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237878AbhKWOOS (ORCPT ); Tue, 23 Nov 2021 09:14:18 -0500 Received: from foss.arm.com ([217.140.110.172]:53566 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236715AbhKWOOH (ORCPT ); Tue, 23 Nov 2021 09:14:07 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 03E26150C; Tue, 23 Nov 2021 06:10:59 -0800 (PST) Received: from e121345-lin.cambridge.arm.com (e121345-lin.cambridge.arm.com [10.1.196.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id DC4C63F66F; Tue, 23 Nov 2021 06:10:57 -0800 (PST) From: Robin Murphy To: joro@8bytes.org, will@kernel.org Cc: iommu@lists.linux-foundation.org, suravee.suthikulpanit@amd.com, baolu.lu@linux.intel.com, willy@infradead.org, linux-kernel@vger.kernel.org, john.garry@huawei.com Subject: [PATCH 4/9] iommu/amd: Simplify pagetable freeing Date: Tue, 23 Nov 2021 14:10:39 +0000 Message-Id: <0a98d76325d6899808afb1118629c22427629c7c.1637671820.git.robin.murphy@arm.com> X-Mailer: git-send-email 2.28.0.dirty In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- drivers/iommu/amd/io_pgtable.c | 78 +++++++++++++--------------------- 1 file changed, 30 insertions(+), 48 deletions(-) diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c index 182c93a43efd..f92ecb3e21d7 100644 --- a/drivers/iommu/amd/io_pgtable.c +++ b/drivers/iommu/amd/io_pgtable.c @@ -84,49 +84,41 @@ 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; + + /* Large PTE? */ + if (PM_PTE_LEVEL(pt[i]) == 0 || + PM_PTE_LEVEL(pt[i]) == 7) + continue; + + 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); } -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) - -static struct page *free_sub_pt(unsigned long root, int mode, - struct page *freelist) +static struct page *free_sub_pt(u64 *root, int mode, struct page *freelist) { switch (mode) { case PAGE_MODE_NONE: @@ -136,19 +128,11 @@ 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 +348,7 @@ 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 +359,7 @@ 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 +496,6 @@ 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 +512,7 @@ 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); } -- 2.28.0.dirty