From patchwork Fri Jan 13 17:10:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Hildenbrand X-Patchwork-Id: 13101403 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 64BD4C3DA78 for ; Fri, 13 Jan 2023 17:29:35 +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=bSzHRRmYCiyv1od9pnaFX56RYhTKFMRQ3yRc40db6Io=; b=XSLlclhdFk1IUz ywmrPlDl5jx4rFGR49FPVhGnnZnJq4757cWpX1IOf4xMc1oVJtzLyqeHZ4bVnu6Kb203VtlJwyojz eHM4jNSsmOCr73WXQV9uervuy6aG8j01K/7jqjQE/cEX1zkC0v0i0E6XOAW0Xzs7mZ69Ez8QUO97L LweWblHee0m13yMg5oMcbB3Q786ti1LkqwLVaI4miHL8CUJhylTsfSOnaTwEI7L7OwwGSTbc8JMJW 9SY82gt8NZ2SA1qMiyiuuNRKmz1vchrLRqBZzD6FPiiXIq2J9vQW7LHXRJtxlrjSfRzwC6hsSK0mA pUCkmmedZOMeoYEUULAw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1pGNqp-003kNE-Dq; Fri, 13 Jan 2023 17:28:24 +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 1pGNcM-003bi1-Rk for linux-arm-kernel@lists.infradead.org; Fri, 13 Jan 2023 17:13:28 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1673630006; 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=u/qx8EisQ9cE7qGuacOvuCI0HccRFINdBBjLGJqKXis=; b=BcGDRUPhDrrCKy5jgq7EP1eJrIX8dfr97jXkhDV43/AF63+Ocf464DI+2TwR7ZbkikNSwV t5vk9AlNMoFO1SLqnha3ltF8zZclhkstwEwhbnfCdmkz0hR4t5Mhx9ZcDOFS26czoN2vgj 3PfXMzhDEPzHIwPvVIrl+P8vlhfcUPM= 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-439-7TH0Gw_VMwKT5Wow9tu7iA-1; Fri, 13 Jan 2023 12:13:18 -0500 X-MC-Unique: 7TH0Gw_VMwKT5Wow9tu7iA-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 E587D811E6E; Fri, 13 Jan 2023 17:13:15 +0000 (UTC) Received: from t480s.fritz.box (unknown [10.39.193.196]) by smtp.corp.redhat.com (Postfix) with ESMTP id 51CB140C2064; Fri, 13 Jan 2023 17:13:09 +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 , "David S. Miller" Subject: [PATCH mm-unstable v1 21/26] sparc/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on 32bit Date: Fri, 13 Jan 2023 18:10:21 +0100 Message-Id: <20230113171026.582290-22-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 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230113_091327_004017_B2AF9C9A X-CRM114-Status: GOOD ( 17.04 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Let's support __HAVE_ARCH_PTE_SWP_EXCLUSIVE by reusing the SRMMU_DIRTY bit as that seems to be safe to reuse inside a swap PTE. This avoids having to steal one bit from the swap offset. While at it, relocate the swap PTE layout documentation and use the same style now used for most other archs. Note that the old documentation was wrong: we use 20 bit for the offset and the reserved bits were 8 instead of 7 bits in the ascii art. Cc: "David S. Miller" Signed-off-by: David Hildenbrand --- arch/sparc/include/asm/pgtable_32.h | 27 ++++++++++++++++++++++++++- arch/sparc/include/asm/pgtsrmmu.h | 14 +++----------- 2 files changed, 29 insertions(+), 12 deletions(-) diff --git a/arch/sparc/include/asm/pgtable_32.h b/arch/sparc/include/asm/pgtable_32.h index 5acc05b572e6..abf7a2601209 100644 --- a/arch/sparc/include/asm/pgtable_32.h +++ b/arch/sparc/include/asm/pgtable_32.h @@ -323,7 +323,16 @@ void srmmu_mapiorange(unsigned int bus, unsigned long xpa, unsigned long xva, unsigned int len); void srmmu_unmapiorange(unsigned long virt_addr, unsigned int len); -/* Encode and de-code a swap entry */ +/* + * 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 ---------------> < type -> E 0 0 0 0 0 0 + */ static inline unsigned long __swp_type(swp_entry_t entry) { return (entry.val >> SRMMU_SWP_TYPE_SHIFT) & SRMMU_SWP_TYPE_MASK; @@ -344,6 +353,22 @@ static inline swp_entry_t __swp_entry(unsigned long type, unsigned long offset) #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) & SRMMU_SWP_EXCLUSIVE; +} + +static inline pte_t pte_swp_mkexclusive(pte_t pte) +{ + return __pte(pte_val(pte) | SRMMU_SWP_EXCLUSIVE); +} + +static inline pte_t pte_swp_clear_exclusive(pte_t pte) +{ + return __pte(pte_val(pte) & ~SRMMU_SWP_EXCLUSIVE); +} + static inline unsigned long __get_phys (unsigned long addr) { diff --git a/arch/sparc/include/asm/pgtsrmmu.h b/arch/sparc/include/asm/pgtsrmmu.h index 6067925972d9..18e68d43f036 100644 --- a/arch/sparc/include/asm/pgtsrmmu.h +++ b/arch/sparc/include/asm/pgtsrmmu.h @@ -53,21 +53,13 @@ #define SRMMU_CHG_MASK (0xffffff00 | SRMMU_REF | SRMMU_DIRTY) -/* SRMMU swap entry encoding - * - * We use 5 bits for the type and 19 for the offset. This gives us - * 32 swapfiles of 4GB each. Encoding looks like: - * - * oooooooooooooooooootttttRRRRRRRR - * fedcba9876543210fedcba9876543210 - * - * The bottom 7 bits are reserved for protection and status bits, especially - * PRESENT. - */ +/* SRMMU swap entry encoding */ #define SRMMU_SWP_TYPE_MASK 0x1f #define SRMMU_SWP_TYPE_SHIFT 7 #define SRMMU_SWP_OFF_MASK 0xfffff #define SRMMU_SWP_OFF_SHIFT (SRMMU_SWP_TYPE_SHIFT + 5) +/* We borrow bit 6 to store the exclusive marker in swap PTEs. */ +#define SRMMU_SWP_EXCLUSIVE SRMMU_DIRTY /* Some day I will implement true fine grained access bits for * user pages because the SRMMU gives us the capabilities to