From patchwork Fri Jan 13 17:10:05 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13101250 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 318D2C678D8 for ; Fri, 13 Jan 2023 17:14:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229917AbjAMROF (ORCPT ); Fri, 13 Jan 2023 12:14:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53494 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229923AbjAMRNn (ORCPT ); Fri, 13 Jan 2023 12:13:43 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6B5E288DE5 for ; Fri, 13 Jan 2023 09:11:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673629888; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=73fMLbo4V7+MiQ5juN7uSvKw/YSpoFxaX5Pl91RBCXU=; b=QrYev/daqjXcDujSW6dLU7O/UiUdu3DV1TP89KY+9Y4zmSuy/yy+dsXYtU7cAsFjoqdeBU genM34oO/tXQK39U324siq3JeMUe7uLG8vlnkc1q4rq9MYKbny4ysT7JYDcMw+OR5vFMoY mA5shwtHvUcaxQBwf9PvVrE+f9nGCgw= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-673-aDHSxwP-Maa5xUp69hE7Ig-1; Fri, 13 Jan 2023 12:11:23 -0500 X-MC-Unique: aDHSxwP-Maa5xUp69hE7Ig-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 98E2A886464; Fri, 13 Jan 2023 17:11:21 +0000 (UTC) Received: from t480s.fritz.box (unknown [10.39.193.196]) by smtp.corp.redhat.com (Postfix) with ESMTP id C8ACB40C2064; Fri, 13 Jan 2023 17:11:14 +0000 (UTC) From: David Hildenbrand To: linux-kernel@vger.kernel.org Cc: Andrew Morton , Hugh Dickins , John Hubbard , Jason Gunthorpe , Mike Rapoport , Yang Shi , Vlastimil Babka , Nadav Amit , Andrea Arcangeli , Peter Xu , linux-mm@kvack.org, x86@kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, loongarch@lists.linux.dev, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, linux-xtensa@linux-xtensa.org, David Hildenbrand , Guo Ren Subject: [PATCH mm-unstable v1 05/26] csky/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE Date: Fri, 13 Jan 2023 18:10:05 +0100 Message-Id: <20230113171026.582290-6-david@redhat.com> In-Reply-To: <20230113171026.582290-1-david@redhat.com> References: <20230113171026.582290-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by stealing one bit from the offset. This reduces the maximum swap space per file to 16 GiB (was 32 GiB). We might actually be able to reuse one of the other software bits (_PAGE_READ / PAGE_WRITE) instead, because we only have to keep pte_present(), pte_none() and HW happy. For now, let's keep it simple because there might be something non-obvious. Cc: Guo Ren Signed-off-by: David Hildenbrand --- arch/csky/abiv1/inc/abi/pgtable-bits.h | 13 +++++++++---- arch/csky/abiv2/inc/abi/pgtable-bits.h | 19 ++++++++++++------- arch/csky/include/asm/pgtable.h | 18 ++++++++++++++++++ 3 files changed, 39 insertions(+), 11 deletions(-) diff --git a/arch/csky/abiv1/inc/abi/pgtable-bits.h b/arch/csky/abiv1/inc/abi/pgtable-bits.h index 752c8b3f9194..ae7a2f76dd42 100644 --- a/arch/csky/abiv1/inc/abi/pgtable-bits.h +++ b/arch/csky/abiv1/inc/abi/pgtable-bits.h @@ -10,6 +10,9 @@ #define _PAGE_ACCESSED (1<<3) #define _PAGE_MODIFIED (1<<4) +/* We borrow bit 9 to store the exclusive marker in swap PTEs. */ +#define _PAGE_SWP_EXCLUSIVE (1<<9) + /* implemented in hardware */ #define _PAGE_GLOBAL (1<<6) #define _PAGE_VALID (1<<7) @@ -26,7 +29,8 @@ #define _PAGE_PROT_NONE _PAGE_READ /* - * Encode and decode a swap entry + * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that + * are !pte_none() && !pte_present(). * * Format of swap PTE: * bit 0: _PAGE_PRESENT (zero) @@ -35,15 +39,16 @@ * bit 6: _PAGE_GLOBAL (zero) * bit 7: _PAGE_VALID (zero) * bit 8: swap type[4] - * bit 9 - 31: swap offset + * bit 9: exclusive marker + * bit 10 - 31: swap offset */ #define __swp_type(x) ((((x).val >> 2) & 0xf) | \ (((x).val >> 4) & 0x10)) -#define __swp_offset(x) ((x).val >> 9) +#define __swp_offset(x) ((x).val >> 10) #define __swp_entry(type, offset) ((swp_entry_t) { \ ((type & 0xf) << 2) | \ ((type & 0x10) << 4) | \ - ((offset) << 9)}) + ((offset) << 10)}) #define HAVE_ARCH_UNMAPPED_AREA diff --git a/arch/csky/abiv2/inc/abi/pgtable-bits.h b/arch/csky/abiv2/inc/abi/pgtable-bits.h index 7e7f389f546f..526152bd2156 100644 --- a/arch/csky/abiv2/inc/abi/pgtable-bits.h +++ b/arch/csky/abiv2/inc/abi/pgtable-bits.h @@ -10,6 +10,9 @@ #define _PAGE_PRESENT (1<<10) #define _PAGE_MODIFIED (1<<11) +/* We borrow bit 7 to store the exclusive marker in swap PTEs. */ +#define _PAGE_SWP_EXCLUSIVE (1<<7) + /* implemented in hardware */ #define _PAGE_GLOBAL (1<<0) #define _PAGE_VALID (1<<1) @@ -26,23 +29,25 @@ #define _PAGE_PROT_NONE _PAGE_WRITE /* - * Encode and decode a swap entry + * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that + * are !pte_none() && !pte_present(). * * Format of swap PTE: * bit 0: _PAGE_GLOBAL (zero) * bit 1: _PAGE_VALID (zero) * bit 2 - 6: swap type - * bit 7 - 8: swap offset[0 - 1] + * bit 7: exclusive marker + * bit 8: swap offset[0] * bit 9: _PAGE_WRITE (zero) * bit 10: _PAGE_PRESENT (zero) - * bit 11 - 31: swap offset[2 - 22] + * bit 11 - 31: swap offset[1 - 21] */ #define __swp_type(x) (((x).val >> 2) & 0x1f) -#define __swp_offset(x) ((((x).val >> 7) & 0x3) | \ - (((x).val >> 9) & 0x7ffffc)) +#define __swp_offset(x) ((((x).val >> 8) & 0x1) | \ + (((x).val >> 10) & 0x3ffffe)) #define __swp_entry(type, offset) ((swp_entry_t) { \ ((type & 0x1f) << 2) | \ - ((offset & 0x3) << 7) | \ - ((offset & 0x7ffffc) << 9)}) + ((offset & 0x1) << 8) | \ + ((offset & 0x3ffffe) << 10)}) #endif /* __ASM_CSKY_PGTABLE_BITS_H */ diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h index 77bc6caff2d2..574c97b9ecca 100644 --- a/arch/csky/include/asm/pgtable.h +++ b/arch/csky/include/asm/pgtable.h @@ -200,6 +200,24 @@ static inline pte_t pte_mkyoung(pte_t pte) return pte; } +#define __HAVE_ARCH_PTE_SWP_EXCLUSIVE +static inline int pte_swp_exclusive(pte_t pte) +{ + return pte_val(pte) & _PAGE_SWP_EXCLUSIVE; +} + +static inline pte_t pte_swp_mkexclusive(pte_t pte) +{ + pte_val(pte) |= _PAGE_SWP_EXCLUSIVE; + return pte; +} + +static inline pte_t pte_swp_clear_exclusive(pte_t pte) +{ + pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE; + return pte; +} + #define __HAVE_PHYS_MEM_ACCESS_PROT struct file; extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,