From nobody Fri Dec 19 20:34:52 2025 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.21]) (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 CD500318142 for ; Tue, 14 Oct 2025 13:07:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.21 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760447271; cv=none; b=qeaK9OmAFH39gj8rG2M26pnFxdOXF/i5/sFRxlEpjpxWkF6RTSPhiA6rXyRQQocbVH60A1PQzns5Ic67dEcOnP/ahaVq1f5h9w7Dq74GgIsIDgmnXpNddgoTKtk1DwMUWTcHwjsE5jvjW/Su0dOKFXCfqlekbZBpLPdQhbiToWI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760447271; c=relaxed/simple; bh=3LqwvcyCTUGBDDv54GKFHPFhtunF891CzWSsBDlRHvg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XtbkqJfWQgPzSIskwisGGqe7B7xQODd5CVkVmWF0RTuYxkLms4t8he/PKU2ir1D4ynt47Pd14yQLVj8LBHZ9HqoJoA91pfWrTqn6hQUPoPvY9eUbqRMwjMEHBSPhpWZG7W+aQva/HRUoL8FU97PWgAxRqnpI1s4/eMOHWAOqroE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=cR/djIVU; arc=none smtp.client-ip=198.175.65.21 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="cR/djIVU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1760447270; x=1791983270; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=3LqwvcyCTUGBDDv54GKFHPFhtunF891CzWSsBDlRHvg=; b=cR/djIVUW9/E+DmNiF9fI6klxUZjTGu1rIqBeY606kVBBa9MEyIJBKVI fIMS3fNVX7j/i2gq24eVQdyF732BL/BnWlPW4NlChuqnMoT+7zTV0XiYP dY34zCVcdfrQjonutslN9eOMAUSp7GvhDP1IgLE77xbfgWtQyhAWkNhlz Be93bQ7meM6NCKobkqDYVw+C1+wuv7EWcsFJ/tlXSRUsiycOq4gp9Z20u MtZ63+zB/WW3Dnbv+kpmCm6J3W4rxz2nbOKs3tpI3Dw8/DpR/gGbdcRpp UfOQnxDA2lz1cimWCfM/JfzCsGtk4uUFSBJ5h3A2xOEXIuln0PllozeaI A==; X-CSE-ConnectionGUID: AqRuVWPERhqgTxssFR7NVQ== X-CSE-MsgGUID: Ei+a9jT1RB2bAHTTViiHAA== X-IronPort-AV: E=McAfee;i="6800,10657,11531"; a="62515378" X-IronPort-AV: E=Sophos;i="6.17,312,1747724400"; d="scan'208";a="62515378" Received: from fmviesa010.fm.intel.com ([10.60.135.150]) by orvoesa113.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Oct 2025 06:07:50 -0700 X-CSE-ConnectionGUID: wkKPsVjuQIOO3qPNmRmAVw== X-CSE-MsgGUID: z+j4SIdnSy2mQrtAx02caw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.19,228,1754982000"; d="scan'208";a="182675618" Received: from allen-box.sh.intel.com ([10.239.159.52]) by fmviesa010.fm.intel.com with ESMTP; 14 Oct 2025 06:07:43 -0700 From: Lu Baolu To: Joerg Roedel , Will Deacon , Robin Murphy , Kevin Tian , Jason Gunthorpe , Jann Horn , Vasant Hegde , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , Alistair Popple , Peter Zijlstra , Uladzislau Rezki , Jean-Philippe Brucker , Andy Lutomirski , Yi Lai , David Hildenbrand , Lorenzo Stoakes , "Liam R . Howlett" , Andrew Morton , Vlastimil Babka , Mike Rapoport , Michal Hocko , Matthew Wilcox Cc: iommu@lists.linux.dev, security@kernel.org, x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Dave Hansen , Lu Baolu Subject: [PATCH v6 3/7] x86/mm: Use 'ptdesc' when freeing PMD pages Date: Tue, 14 Oct 2025 21:04:33 +0800 Message-ID: <20251014130437.1090448-4-baolu.lu@linux.intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251014130437.1090448-1-baolu.lu@linux.intel.com> References: <20251014130437.1090448-1-baolu.lu@linux.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Dave Hansen There are a billion ways to refer to a physical memory address. One of the x86 PMD freeing code location chooses to use a 'pte_t *' to point to a PMD page and then call a PTE-specific freeing function for it. That's a bit wonky. Just use a 'struct ptdesc *' instead. Its entire purpose is to refer to page table pages. It also means being able to remove an explicit cast. Right now, pte_free_kernel() is a one-liner that calls pagetable_dtor_free(). Effectively, all this patch does is remove one superfluous __pa(__va(paddr)) conversion and then call pagetable_dtor_free() directly instead of through a helper. Signed-off-by: Dave Hansen Signed-off-by: Lu Baolu Reviewed-by: Jason Gunthorpe Reviewed-by: Kevin Tian --- include/linux/mm.h | 6 ++++-- arch/x86/mm/pgtable.c | 12 ++++++------ 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 15ce0c415d36..94e2ec6c5685 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3203,8 +3203,7 @@ pte_t *pte_offset_map_rw_nolock(struct mm_struct *mm,= pmd_t *pmd, ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd))? \ NULL: pte_offset_kernel(pmd, address)) =20 -#if defined(CONFIG_SPLIT_PMD_PTLOCKS) - +#if defined(CONFIG_SPLIT_PMD_PTLOCKS) || defined(CONFIG_X86_64) static inline struct page *pmd_pgtable_page(pmd_t *pmd) { unsigned long mask =3D ~(PTRS_PER_PMD * sizeof(pmd_t) - 1); @@ -3215,6 +3214,9 @@ static inline struct ptdesc *pmd_ptdesc(pmd_t *pmd) { return page_ptdesc(pmd_pgtable_page(pmd)); } +#endif + +#if defined(CONFIG_SPLIT_PMD_PTLOCKS) =20 static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd) { diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c index ddf248c3ee7d..c830ccbc2fd8 100644 --- a/arch/x86/mm/pgtable.c +++ b/arch/x86/mm/pgtable.c @@ -729,7 +729,7 @@ int pmd_clear_huge(pmd_t *pmd) int pud_free_pmd_page(pud_t *pud, unsigned long addr) { pmd_t *pmd, *pmd_sv; - pte_t *pte; + struct ptdesc *pt; int i; =20 pmd =3D pud_pgtable(*pud); @@ -750,8 +750,8 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr) =20 for (i =3D 0; i < PTRS_PER_PMD; i++) { if (!pmd_none(pmd_sv[i])) { - pte =3D (pte_t *)pmd_page_vaddr(pmd_sv[i]); - pte_free_kernel(&init_mm, pte); + pt =3D pmd_ptdesc(&pmd_sv[i]); + pagetable_dtor_free(pt); } } =20 @@ -772,15 +772,15 @@ int pud_free_pmd_page(pud_t *pud, unsigned long addr) */ int pmd_free_pte_page(pmd_t *pmd, unsigned long addr) { - pte_t *pte; + struct ptdesc *pt; =20 - pte =3D (pte_t *)pmd_page_vaddr(*pmd); + pt =3D pmd_ptdesc(pmd); pmd_clear(pmd); =20 /* INVLPG to clear all paging-structure caches */ flush_tlb_kernel_range(addr, addr + PAGE_SIZE-1); =20 - pte_free_kernel(&init_mm, pte); + pagetable_dtor_free(pt); =20 return 1; } --=20 2.43.0