From patchwork Tue Dec 6 14:47:11 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13065892 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 2A284C4708C for ; Tue, 6 Dec 2022 14:52:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235171AbiLFOwK (ORCPT ); Tue, 6 Dec 2022 09:52:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235297AbiLFOvc (ORCPT ); Tue, 6 Dec 2022 09:51:32 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B89EC2E9DA for ; Tue, 6 Dec 2022 06:48:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1670338133; 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=m3HgZoiBdRe2+qxYMQ72TFwa7GczY3f363Bjai/2ODc=; b=LvhqHQPIRePtVNqFjM3Vndgxjlpe45QOQXdCOggTrBfOXYrPRoFdJjNwSt4LFMjZcoVCgR rtrRZWEozFfx4spm2CgFpKyctBiyehIurFO2H/7WSpAP7u9NTai9LgVWXCf4YxNgh8Ro7p /OA5kViL7C2xZ1Gcn1izR0i5zZ0JdMM= 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-300-1x9UA2_6OruWRg3WBRCK0w-1; Tue, 06 Dec 2022 09:48:50 -0500 X-MC-Unique: 1x9UA2_6OruWRg3WBRCK0w-1 Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 3A10185A588; Tue, 6 Dec 2022 14:48:49 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.193.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id D692C492B04; Tue, 6 Dec 2022 14:48:43 +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 Subject: [PATCH mm-unstable RFC 07/26] ia64/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE Date: Tue, 6 Dec 2022 15:47:11 +0100 Message-Id: <20221206144730.163732-8-david@redhat.com> In-Reply-To: <20221206144730.163732-1-david@redhat.com> References: <20221206144730.163732-1-david@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 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 type. Generic MM currently only uses 5 bits for the type (MAX_SWAPFILES_SHIFT), so the stolen bit is effectively unused. While at it, also mask the type in __swp_entry(). Signed-off-by: David Hildenbrand --- arch/ia64/include/asm/pgtable.h | 32 +++++++++++++++++++++++++++++--- 1 file changed, 29 insertions(+), 3 deletions(-) diff --git a/arch/ia64/include/asm/pgtable.h b/arch/ia64/include/asm/pgtable.h index 01517a5e6778..d666eb229d4b 100644 --- a/arch/ia64/include/asm/pgtable.h +++ b/arch/ia64/include/asm/pgtable.h @@ -58,6 +58,9 @@ #define _PAGE_ED (__IA64_UL(1) << 52) /* exception deferral */ #define _PAGE_PROTNONE (__IA64_UL(1) << 63) +/* We borrow bit 7 to store the exclusive marker in swap PTEs. */ +#define _PAGE_SWP_EXCLUSIVE (1 << 7) + #define _PFN_MASK _PAGE_PPN_MASK /* Mask of bits which may be changed by pte_modify(); the odd bits are there for _PAGE_PROTNONE */ #define _PAGE_CHG_MASK (_PAGE_P | _PAGE_PROTNONE | _PAGE_PL_MASK | _PAGE_AR_MASK | _PAGE_ED) @@ -399,6 +402,9 @@ extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; extern void paging_init (void); /* + * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that + * are !pte_none() && !pte_present(). + * * Note: The macros below rely on the fact that MAX_SWAPFILES_SHIFT <= number of * bits in the swap-type field of the swap pte. It would be nice to * enforce that, but we can't easily include here. @@ -406,16 +412,36 @@ extern void paging_init (void); * * Format of swap pte: * bit 0 : present bit (must be zero) - * bits 1- 7: swap-type + * bits 1- 6: swap type + * bit 7 : exclusive marker * bits 8-62: swap offset * bit 63 : _PAGE_PROTNONE bit */ -#define __swp_type(entry) (((entry).val >> 1) & 0x7f) +#define __swp_type(entry) (((entry).val >> 1) & 0x3f) #define __swp_offset(entry) (((entry).val << 1) >> 9) -#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << 1) | ((long) (offset) << 8) }) +#define __swp_entry(type,offset) ((swp_entry_t) { ((type & 0x3f) << 1) | \ + ((long) (offset) << 8) }) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val }) +#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; +} + /* * ZERO_PAGE is a global shared page that is always zero: used * for zero-mapped memory areas etc..