From mboxrd@z Thu Jan 1 00:00:00 1970 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 48962C7618A for ; Mon, 20 Mar 2023 10:54:39 +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-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:Cc:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=06cKSrvdXXvCvRz2GdedNwzo+jS6QlVAGiuf2wdzq00=; b=jG3ZlulDVZyWya sXa+FgYOe76u9JleycPEcY1E5s2pT8+iWU/Urnp0B2wNb2QLoDJzGAokB6jtMqe23XMBUxIS8pDQD NMvuvHU20/FmbpgdWZ6Q8/scx4L9vGW0MgxXG9Sk/a7qTRJxG8sV9nIWJxtFyTGnIHoYLQZQH1055 ef0bcLZra1c3yKhZBoWufvhX9rfKien4mciThp8s+ziqz/YMu6Ti/lvKeYKutpHKGjm/k1UVTn3qR WfQOhs3N9Y1Sr1SqSo92wSHnJmw/wP3TswtbPsdJmk8KDyaHsJx/Jnv0WrebkmBm6THHcOu08Rsu/ GcWj/OuC5J1hteB3z9bQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1peD9s-008ihC-2U; Mon, 20 Mar 2023 10:54:32 +0000 Received: from relay7-d.mail.gandi.net ([2001:4b98:dc4:8::227]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1peD9n-008idY-2F; Mon, 20 Mar 2023 10:54:29 +0000 Received: (Authenticated sender: alex@ghiti.fr) by mail.gandi.net (Postfix) with ESMTPSA id 2F98D20003; Mon, 20 Mar 2023 10:54:14 +0000 (UTC) Message-ID: Date: Mon, 20 Mar 2023 11:54:14 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.8.0 Subject: Re: [PATCH v8 2/4] mm: Introduce memblock_isolate_memory Content-Language: en-US To: Mike Rapoport , Alexandre Ghiti Cc: Catalin Marinas , Will Deacon , Paul Walmsley , Palmer Dabbelt , Albert Ou , Rob Herring , Frank Rowand , Andrew Morton , Anup Patel , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org, devicetree@vger.kernel.org, linux-mm@kvack.org References: <20230316131711.1284451-1-alexghiti@rivosinc.com> <20230316131711.1284451-3-alexghiti@rivosinc.com> From: Alexandre Ghiti In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230320_035428_075135_F0FBA0BC X-CRM114-Status: GOOD ( 21.35 ) 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: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Hi Mike, On 3/16/23 21:12, Mike Rapoport wrote: > Hi Alexandre, > > On Thu, Mar 16, 2023 at 02:17:09PM +0100, Alexandre Ghiti wrote: >> This function allows to split a region in memblock.memory and will be >> useful when setting up the linear mapping with STRICT_KERNEL_RWX: it >> allows to isolate the kernel text/rodata and then avoid to map those >> regions with a PUD/P4D/PGD. > > Sorry I've missed it last time. The changelog is fine in the context of No worries :) > this series, but if you look at it as a part of memblock changelog it > doesn't provide enough background on why memblock_isolate_memory() is > useful. > > Can you please add more context so it would be self explanatory? What about: "memblock.memory contains the list of memory regions and a memory region can cover memory that will be mapped with different permissions. So to ease the mapping process, allow to isolate those regions by introducing a new function called memblock_isolate_memory. This will be used in arch specific code to isolate the kernel text/rodata regions when STRICT_KERNEL_RWX is enabled so that we avoid mapping them with PUD/P4D/PGD mappings." Thanks, Alex > >> Signed-off-by: Alexandre Ghiti >> Reviewed-by: Anup Patel >> Tested-by: Anup Patel >> --- >> include/linux/memblock.h | 1 + >> mm/memblock.c | 20 ++++++++++++++++++++ >> 2 files changed, 21 insertions(+) >> >> diff --git a/include/linux/memblock.h b/include/linux/memblock.h >> index 50ad19662a32..2f7ef97c0da7 100644 >> --- a/include/linux/memblock.h >> +++ b/include/linux/memblock.h >> @@ -125,6 +125,7 @@ int memblock_clear_hotplug(phys_addr_t base, phys_addr_t size); >> int memblock_mark_mirror(phys_addr_t base, phys_addr_t size); >> int memblock_mark_nomap(phys_addr_t base, phys_addr_t size); >> int memblock_clear_nomap(phys_addr_t base, phys_addr_t size); >> +int memblock_isolate_memory(phys_addr_t base, phys_addr_t size); >> >> void memblock_free_all(void); >> void memblock_free(void *ptr, size_t size); >> diff --git a/mm/memblock.c b/mm/memblock.c >> index 25fd0626a9e7..e8c651a37012 100644 >> --- a/mm/memblock.c >> +++ b/mm/memblock.c >> @@ -805,6 +805,26 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, >> return 0; >> } >> >> +/** >> + * memblock_isolate_memory - isolate given range in memblock.memory >> + * @base: base of range to isolate >> + * @size: size of range to isolate >> + * >> + * Isolates the given range in memblock.memory so that it does not share any >> + * region with other ranges. >> + * >> + * Return: >> + * 0 on success, -errno on failure. >> + */ >> + >> +int __init_memblock memblock_isolate_memory(phys_addr_t base, phys_addr_t size) >> +{ >> + int start_rgn, end_rgn; >> + >> + return memblock_isolate_range(&memblock.memory, base, size, >> + &start_rgn, &end_rgn); >> +} >> + >> static int __init_memblock memblock_remove_range(struct memblock_type *type, >> phys_addr_t base, phys_addr_t size) >> { >> -- >> 2.37.2 >> _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv