From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A333D4DD6FD; Tue, 21 Jul 2026 16:24:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784651077; cv=none; b=QU2lV1B7Ht5OZXXo+cavTVt4cYEB8XLDlEi8i1Ca9j4jqyms+YjZ9aqWYsSONIBXdTCqX5mY2YvSIZAI2C31LG0FCG0P7H07SYMNPDaEfXtxfmIsLXgErW8gx95WE4eWTz9f+mqcC9+7CFJFF5muWBXMjn9qoxMdu8qBp4YSbXE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784651077; c=relaxed/simple; bh=ZyULvIQHjX0BEINxRsy6s9H95na0E7R/g5l9tojUy5c=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=KIcQcaebguyKYuvbcLqReLm8axCKarKUHb1+2C6nHsQ/NH5bwtcQw3sVo5myeOihb4oUHlSfheYEUgbf8xNiN9M11/2X8MBQdl15bo2VeTZcYnasRWsOV91IRr2Ds6WTiILX3qlQauCk+bofX84S1oplEExKKrfChhMNPzrxPj8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Y40sTc2v; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Y40sTc2v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 370D11F000E9; Tue, 21 Jul 2026 16:24:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784651076; bh=s+fAGwkj37+ME7Pb0rsrK6LPOBZGydYbqjFxeMM43qs=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=Y40sTc2vrbeiNxDRxijWQmoLZupCjYYBLIzRIrURtoo3cDYHr5ZhKX2eqWO5Ns/9M VWE7/yT06n+QRfyjogcDC45ebqMMD7SdkLyRKsNKmMuL5obaqIIuDsCjanWsgfwzrw cNesCrWBJcDQ75nQP1mhcRx593LcEO94fvoZMWlfhl1r0xwzsbMZ9+NX+FEMYVsT+F mKy8et9CuedtDDog/EjWVPYtVcr1/Kaiz0PWF3WoioZkDaWdkK8y+MHKL1arlrbJeB Ph2fAs7rl++yRte5vI2YNioSX3LdjWLts0yl4+kaXBmoTOVKSN+a2vBm/IfjtVTZq6 sZT1yAdoXsXcA== From: "Mike Rapoport (Microsoft)" Date: Tue, 21 Jul 2026 19:23:31 +0300 Subject: [PATCH RFC 08/18] x86/mm/pat: use cpa_split_data structure to pass split parameters Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260721-generic-set-memory-v0-1-v1-8-2c1fc62306b3@kernel.org> References: <20260721-generic-set-memory-v0-1-v1-0-2c1fc62306b3@kernel.org> In-Reply-To: <20260721-generic-set-memory-v0-1-v1-0-2c1fc62306b3@kernel.org> To: linux-mm@kvack.org Cc: Albert Ou , Andrew Morton , Andy Lutomirski , Borislav Petkov , Brendan Jackman , Catalin Marinas , Dave Hansen , David Hildenbrand , Huacai Chen , Ingo Molnar , Ingo Molnar , Kevin Brodsky , "Liam R. Howlett" , Lorenzo Stoakes , Michal Hocko , Mike Rapoport , Palmer Dabbelt , Paul Walmsley , Peter Zijlstra , "H. Peter Anvin" , Suren Baghdasaryan , Thomas Gleixner , Vlastimil Babka , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, loongarch@lists.linux.dev, x86@kernel.org X-Mailer: b4 0.16-dev Keeping all split parameters in a struct between should_split_large_page() and split_large_page() allows maintaining the split state that is initially established in cpa_handle_large_page(), then this state is updated in should_split_large_page() and finally consumed by split_large_page(). Start passing parameters between should_split_large_page() and split_large_page() in cpa_split_data structure. As the first step only pass the existing parameters in the new structure. No functional change intended. Assisted-by: Copilot:claude-opus-4.8 Signed-off-by: Mike Rapoport (Microsoft) --- arch/x86/mm/pat/set_memory.c | 49 ++++++++++++++++++++++++++++---------------- 1 file changed, 31 insertions(+), 18 deletions(-) diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c index a9d270e986ff..c2a72cd8b832 100644 --- a/arch/x86/mm/pat/set_memory.c +++ b/arch/x86/mm/pat/set_memory.c @@ -53,6 +53,15 @@ struct cpa_data { struct page **pages; }; +/* + * context for checking for a split a large page and splitting it if required. + */ +struct cpa_split_data { + unsigned long address; + pte_t *kpte; + struct ptdesc *ptdesc; +}; + enum cpa_warn { CPA_CONFLICT, CPA_PROTECT, @@ -869,12 +878,14 @@ static pgprot_t pgprot_clear_protnone_bits(pgprot_t prot) return prot; } -static int __should_split_large_page(pte_t *kpte, unsigned long address, - struct cpa_data *cpa) +static int __should_split_large_page(struct cpa_data *cpa, + struct cpa_split_data *sd) { unsigned long numpages, pmask, psize, lpaddr, pfn, old_pfn; pgprot_t old_prot, new_prot, req_prot, chk_prot; + unsigned long address = sd->address; enum pgtable_level level; + pte_t *kpte = sd->kpte; pte_t new_pte, *tmp; bool nx, rw; @@ -1016,8 +1027,8 @@ static int __should_split_large_page(pte_t *kpte, unsigned long address, return 0; } -static int should_split_large_page(pte_t *kpte, unsigned long address, - struct cpa_data *cpa) +static int should_split_large_page(struct cpa_data *cpa, + struct cpa_split_data *sd) { int do_split; @@ -1025,7 +1036,7 @@ static int should_split_large_page(pte_t *kpte, unsigned long address, return 1; spin_lock(&pgd_lock); - do_split = __should_split_large_page(kpte, address, cpa); + do_split = __should_split_large_page(cpa, sd); spin_unlock(&pgd_lock); return do_split; @@ -1067,13 +1078,14 @@ static void split_set_pte(struct cpa_data *cpa, pte_t *pte, unsigned long pfn, set_pte(pte, pfn_pte(pfn, ref_prot)); } -static int -__split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address, - struct ptdesc *ptdesc) +static int __split_large_page(struct cpa_data *cpa, struct cpa_split_data *sd) { unsigned long lpaddr, lpinc, ref_pfn, pfn, pfninc = 1; + struct ptdesc *ptdesc = sd->ptdesc; struct page *base = ptdesc_page(ptdesc); pte_t *pbase = (pte_t *)page_address(base); + unsigned long address = sd->address; + pte_t *kpte = sd->kpte; unsigned int i, level; pgprot_t ref_prot; bool nx, rw; @@ -1174,19 +1186,16 @@ __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address, return 0; } -static int split_large_page(struct cpa_data *cpa, pte_t *kpte, - unsigned long address) +static int split_large_page(struct cpa_data *cpa, struct cpa_split_data *sd) { - struct ptdesc *ptdesc; - spin_unlock(&cpa_lock); - ptdesc = pagetable_alloc(GFP_KERNEL, 0); + sd->ptdesc = pagetable_alloc(GFP_KERNEL, 0); spin_lock(&cpa_lock); - if (!ptdesc) + if (!sd->ptdesc) return -ENOMEM; - if (__split_large_page(cpa, kpte, address, ptdesc)) - pagetable_free(ptdesc); + if (__split_large_page(cpa, sd)) + pagetable_free(sd->ptdesc); return 0; } @@ -1194,13 +1203,17 @@ static int split_large_page(struct cpa_data *cpa, pte_t *kpte, static int cpa_handle_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address) { + struct cpa_split_data sd = { + .address = address, + .kpte = kpte, + }; int do_split, err; /* * Check, whether we can keep the large page intact * and just change the pte: */ - do_split = should_split_large_page(kpte, address, cpa); + do_split = should_split_large_page(cpa, &sd); /* * When the range fits into the existing large page, no split is * required. @@ -1213,7 +1226,7 @@ static int cpa_handle_large_page(struct cpa_data *cpa, pte_t *kpte, /* * We have to split the large page: */ - err = split_large_page(cpa, kpte, address); + err = split_large_page(cpa, &sd); if (err) return err; -- 2.53.0