From patchwork Tue Dec 6 14:47:19 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13066016 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 12333C352A1 for ; Tue, 6 Dec 2022 15:02:23 +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-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=O87E9eFxdFz+Tkj2YORj8zPtp2/mH0HYNxWly3/kBvo=; b=OeJIlEDl6aECoO bYiz2/EqDeR1z0JFbwQk+B47joP1K9TVQxys4hHS6+8o361eJsrX2DgpLixfpDezUDHzMo6JurBny BCGAo4cJ7tnM+HBP9uS19REBnxod7gTLSVkw9grWdsUiWuMx14mKNIxqGqnJ6hTVXgaT2ZDfi3ks7 jXf9AzqcWsRSbt5diPMPbv7dlGrj1XEe/V/TGZf/jHiLmeLWctcyaWCw30ggNEOJeqSRplcGVtEk+ dqY7ifWkVc3a0rJ0XSh5vaPk3q34BaCyzrLLSBYeT4A+KqF16tWProEl+yQgtFy+2o0cZRT66Cc8R +IeIvJ/IEuRtxnyDZ9ZA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1p2ZSS-00BvYM-6W; Tue, 06 Dec 2022 15:02:08 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1p2ZGV-00Bi7e-F0 for linux-riscv@lists.infradead.org; Tue, 06 Dec 2022 14:49:53 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1670338186; 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=biZUSi6WKeYFDAMvlVAPp7xwZgMGdk+ThRBBgnt2h2Y=; b=R6/Pq/tO4aB+Ru3WTgid4xvP4ClTXhbnTzN/wS6c31Y5rAcFQV/PsTSNVGKjJz8otEFe4/ 9CzLLAamf7//hpYz4P1iIG0NdV/fk5RtvQMbM5RNds4z/SVCvIMafjoFsYlKHU4FJDOimB njmKrAEHM6srK3QZl0B6w7ruzsX2mao= 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-645-75sMW2SGNRiOi-eUzMQ42g-1; Tue, 06 Dec 2022 09:49:42 -0500 X-MC-Unique: 75sMW2SGNRiOi-eUzMQ42g-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 9EBD3833A1E; Tue, 6 Dec 2022 14:49:40 +0000 (UTC) Received: from t480s.redhat.com (unknown [10.39.193.173]) by smtp.corp.redhat.com (Postfix) with ESMTP id DC2C8492B04; Tue, 6 Dec 2022 14:49:34 +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 , Stefan Kristiansson , Stafford Horne Subject: [PATCH mm-unstable RFC 15/26] openrisc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE Date: Tue, 6 Dec 2022 15:47:19 +0100 Message-Id: <20221206144730.163732-16-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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221206_064947_636016_5E9C8AD1 X-CRM114-Status: GOOD ( 15.17 ) 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: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.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, mask the type in __swp_entry(). Cc: Stefan Kristiansson Cc: Stafford Horne Signed-off-by: David Hildenbrand --- arch/openrisc/include/asm/pgtable.h | 41 +++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 5 deletions(-) diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h index 6477c17b3062..903b32d662ab 100644 --- a/arch/openrisc/include/asm/pgtable.h +++ b/arch/openrisc/include/asm/pgtable.h @@ -154,6 +154,9 @@ extern void paging_init(void); #define _KERNPG_TABLE \ (_PAGE_BASE | _PAGE_SRE | _PAGE_SWE | _PAGE_ACCESSED | _PAGE_DIRTY) +/* We borrow bit 11 to store the exclusive marker in swap PTEs. */ +#define _PAGE_SWP_EXCLUSIVE _PAGE_U_SHARED + #define PAGE_NONE __pgprot(_PAGE_ALL) #define PAGE_READONLY __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE) #define PAGE_READONLY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC) @@ -385,16 +388,44 @@ static inline void update_mmu_cache(struct vm_area_struct *vma, /* __PHX__ FIXME, SWAP, this probably doesn't work */ -/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */ -/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */ - -#define __swp_type(x) (((x).val >> 5) & 0x7f) +/* + * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that + * are !pte_none() && !pte_present(). + * + * Format of swap PTEs: + * + * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 + * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 + * <-------------- offset ---------------> E <- type --> 0 0 0 0 0 + * + * E is the exclusive marker that is not stored in swap entries. + * The zero'ed bits include _PAGE_PRESENT. + */ +#define __swp_type(x) (((x).val >> 5) & 0x3f) #define __swp_offset(x) ((x).val >> 12) #define __swp_entry(type, offset) \ - ((swp_entry_t) { ((type) << 5) | ((offset) << 12) }) + ((swp_entry_t) { (((type) & 0x3f) << 5) | ((offset) << 12) }) #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; +} + typedef pte_t *pte_addr_t; #endif /* __ASSEMBLY__ */