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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8E908D1267A for ; Tue, 5 Nov 2024 10:25:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=JM9Z8c4rv3qjxrcB7AqMJ0h1S2W4X+arCkHDdS/ZwO4=; b=QVl3qZZkKF4VNr dBgqfNpDJ8dg/WJvJzqOfxMzjX/6m5jSoicAz0rSEVRuVu6yZQU3ydM9kwpYoxKNd7h/MuR+aLfrg YWsXEVyaPX//saIxobBdPLkQU9jLF8IyxSbkDxTkoSssPxtrjSJBRSU//vXh4bsEmQ1WRlzKp1eHn RKb/nna+cb3v2QJF4zKHeM4YP5i+Ya0uzB4MAdExCV5CH9PdT3q//hGOR8yDJO/B+PXwEwjbMqUKL GndIx1ZUrUxdNOXN4Y+8U/CEzIzwM8HbzoDRyJIJ3S8qMyOlJU9RVgCU510AN0/u83v/Ms+jorIUn yScmfZ19o7ftTSqeslAg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t8GkI-0000000GfOf-3DWP; Tue, 05 Nov 2024 10:25:10 +0000 Received: from relay5-d.mail.gandi.net ([2001:4b98:dc4:8::225]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t8GkF-0000000GfMz-2tsZ for linux-riscv@lists.infradead.org; Tue, 05 Nov 2024 10:25:09 +0000 Received: by mail.gandi.net (Postfix) with ESMTPSA id E22181C0003; Tue, 5 Nov 2024 10:25:01 +0000 (UTC) Message-ID: <38936e70-e293-446a-8efc-208d52e42573@ghiti.fr> Date: Tue, 5 Nov 2024 11:25:01 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 02/11] riscv: mm: Increment PFN in place when splitting mappings Content-Language: en-US To: Samuel Holland , Palmer Dabbelt , linux-riscv@lists.infradead.org, Conor Dooley Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Alexandre Ghiti , Lad Prabhakar , Emil Renner Berthing , Rob Herring , Krzysztof Kozlowski References: <20241102000843.1301099-1-samuel.holland@sifive.com> <20241102000843.1301099-3-samuel.holland@sifive.com> From: Alexandre Ghiti In-Reply-To: <20241102000843.1301099-3-samuel.holland@sifive.com> X-GND-Sasl: alex@ghiti.fr X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241105_022508_083140_273B82B3 X-CRM114-Status: GOOD ( 17.45 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Hi Samuel, On 02/11/2024 01:07, Samuel Holland wrote: > The current code separates page table entry values into a PFN and a > pgprot_t before incrementing the PFN and combining the two parts using > pfn_pXX(). On some hardware with custom page table formats or memory > aliases, the pfn_pXX() functions need to transform the PTE value, so > these functions would need to apply the opposite transformation when > breaking apart the PTE value. > > However, both transformations can be avoided by incrementing the PFN in > place, as done by pte_advance_pfn() and set_ptes(). > > Signed-off-by: Samuel Holland > --- > > arch/riscv/mm/pageattr.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/arch/riscv/mm/pageattr.c b/arch/riscv/mm/pageattr.c > index 271d01a5ba4d..335060adc1a6 100644 > --- a/arch/riscv/mm/pageattr.c > +++ b/arch/riscv/mm/pageattr.c > @@ -109,9 +109,8 @@ static int __split_linear_mapping_pmd(pud_t *pudp, > continue; > > if (pmd_leaf(pmdp_get(pmdp))) { > + pte_t pte = pmd_pte(pmdp_get(pmdp)); > struct page *pte_page; > - unsigned long pfn = _pmd_pfn(pmdp_get(pmdp)); > - pgprot_t prot = __pgprot(pmd_val(pmdp_get(pmdp)) & ~_PAGE_PFN_MASK); > pte_t *ptep_new; > int i; > > @@ -121,7 +120,7 @@ static int __split_linear_mapping_pmd(pud_t *pudp, > > ptep_new = (pte_t *)page_address(pte_page); > for (i = 0; i < PTRS_PER_PTE; ++i, ++ptep_new) > - set_pte(ptep_new, pfn_pte(pfn + i, prot)); > + set_pte(ptep_new, pte_advance_pfn(pte, i)); > > smp_wmb(); > > @@ -149,9 +148,8 @@ static int __split_linear_mapping_pud(p4d_t *p4dp, > continue; > > if (pud_leaf(pudp_get(pudp))) { > + pmd_t pmd = __pmd(pud_val(pudp_get(pudp))); Nit: You could use pud_pte() here. > struct page *pmd_page; > - unsigned long pfn = _pud_pfn(pudp_get(pudp)); > - pgprot_t prot = __pgprot(pud_val(pudp_get(pudp)) & ~_PAGE_PFN_MASK); > pmd_t *pmdp_new; > int i; > > @@ -162,7 +160,8 @@ static int __split_linear_mapping_pud(p4d_t *p4dp, > pmdp_new = (pmd_t *)page_address(pmd_page); > for (i = 0; i < PTRS_PER_PMD; ++i, ++pmdp_new) > set_pmd(pmdp_new, > - pfn_pmd(pfn + ((i * PMD_SIZE) >> PAGE_SHIFT), prot)); > + __pmd(pmd_val(pmd) + > + (i << (PMD_SHIFT - PAGE_SHIFT + PFN_PTE_SHIFT)))); Nit: Here you could use pte_advance_pfn(pmd, i << (PMD_SHIFT - PAGE_SHIFT)) > > smp_wmb(); > > @@ -198,9 +197,8 @@ static int __split_linear_mapping_p4d(pgd_t *pgdp, > continue; > > if (p4d_leaf(p4dp_get(p4dp))) { > + pud_t pud = __pud(p4d_val(p4dp_get(p4dp))); > struct page *pud_page; > - unsigned long pfn = _p4d_pfn(p4dp_get(p4dp)); > - pgprot_t prot = __pgprot(p4d_val(p4dp_get(p4dp)) & ~_PAGE_PFN_MASK); > pud_t *pudp_new; > int i; > > @@ -215,7 +213,8 @@ static int __split_linear_mapping_p4d(pgd_t *pgdp, > pudp_new = (pud_t *)page_address(pud_page); > for (i = 0; i < PTRS_PER_PUD; ++i, ++pudp_new) > set_pud(pudp_new, > - pfn_pud(pfn + ((i * PUD_SIZE) >> PAGE_SHIFT), prot)); > + __pud(pud_val(pud) + > + (i << (PUD_SHIFT - PAGE_SHIFT + PFN_PTE_SHIFT)))); Nit: Ditto > > /* > * Make sure the pud filling is not reordered with the Other than the nits (which are up to you), you can add: Reviewed-by: Alexandre Ghiti Thanks, Alex _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv