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 78BFDC27C55 for ; Mon, 10 Jun 2024 20:49:15 +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=hSbOeJtdppIorEgJgGtLljzGCALTLOdLhRdHjl2xMwk=; b=ke9PtIM7/CFMHV qMwonNqL09976oXXX/kvEn807TuubHtI407rgDCJ+eaQXbJ0kf7kUF4/JOTQp/bVC3FmRsL5PM7hV vSpijKeb4zE2NgPXVKjx5oxvypkDnvqlASog6Nx4aCVU78+BIw4BVHWOdWUUeBqsZY6ZZUr9hirmx shMrwjEYWh9EQK48uNSRxLS1exr6I1L6D2eop/2tJ5lOHPNjO7X0AkBxIqStQAAEQdqZjhPLvOtVa nqSbzEEr6xsFdjj8MX3Qw2PznDj+OWjvcpGZU0cfrBIxpl3QN5TqhN7NfEMGrq0oAi+Zih9AVauG1 aSchDlToRqTSN4iKNxxQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sGlwo-00000006R3m-1sgF; Mon, 10 Jun 2024 20:48:58 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sGlwg-00000006Qws-0Ig8 for linux-arm-kernel@lists.infradead.org; Mon, 10 Jun 2024 20:48:51 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 856A460C31; Mon, 10 Jun 2024 20:48:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 12469C2BBFC; Mon, 10 Jun 2024 20:48:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1718052529; bh=MfMv4iuvVtYp4fD/Tz2vUcjF5O+YDb2bOLk4u2a4UXw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oNUVm+WZChQbUcGuxj0iePgzWN/STCk1UDe6eSft6fNqLQzRWj+cEg6N7Iub4DgQT gFmRbO2VfLFjfkDGuPpTzofcmjldor6JMmMVNRboHNJ+QDhCRD1vXvPcqriY2jlZwk nb0xo8U5Gn6m4lnOBGwcfoDV9Lp536H4cH2d1m6E= From: Linus Torvalds To: Peter Anvin , Ingo Molnar , Borislav Petkov , Thomas Gleixner , Rasmus Villemoes , Josh Poimboeuf , Catalin Marinas , Will Deacon Cc: Linux Kernel Mailing List , the arch/x86 maintainers , linux-arm-kernel@lists.infradead.org, linux-arch , Linus Torvalds Subject: [PATCH 2/7] add default dummy 'runtime constant' infrastructure Date: Mon, 10 Jun 2024 13:48:16 -0700 Message-ID: <20240610204821.230388-3-torvalds@linux-foundation.org> X-Mailer: git-send-email 2.45.1.209.gc6f12300df In-Reply-To: <20240610204821.230388-1-torvalds@linux-foundation.org> References: <20240610204821.230388-1-torvalds@linux-foundation.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240610_134850_249238_41DD6AD6 X-CRM114-Status: GOOD ( 20.85 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This adds the initial dummy support for 'runtime constants' for when an architecture doesn't actually support an implementation of fixing up said runtime constants. This ends up being the fallback to just using the variables as regular __ro_after_init variables, and changes the dcache d_hash() function to use this model. Signed-off-by: Linus Torvalds --- fs/dcache.c | 11 ++++++++++- include/asm-generic/Kbuild | 1 + include/asm-generic/runtime-const.h | 15 +++++++++++++++ include/asm-generic/vmlinux.lds.h | 8 ++++++++ 4 files changed, 34 insertions(+), 1 deletion(-) create mode 100644 include/asm-generic/runtime-const.h diff --git a/fs/dcache.c b/fs/dcache.c index 8b4382f5c99d..5d3a5b315692 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -35,6 +35,8 @@ #include "internal.h" #include "mount.h" +#include + /* * Usage: * dcache->d_inode->i_lock protects: @@ -102,7 +104,8 @@ static struct hlist_bl_head *dentry_hashtable __ro_after_init; static inline struct hlist_bl_head *d_hash(unsigned long hashlen) { - return dentry_hashtable + ((u32)hashlen >> d_hash_shift); + return runtime_const_ptr(dentry_hashtable) + + runtime_const_shift_right_32(hashlen, d_hash_shift); } #define IN_LOOKUP_SHIFT 10 @@ -3129,6 +3132,9 @@ static void __init dcache_init_early(void) 0, 0); d_hash_shift = 32 - d_hash_shift; + + runtime_const_init(shift, d_hash_shift); + runtime_const_init(ptr, dentry_hashtable); } static void __init dcache_init(void) @@ -3157,6 +3163,9 @@ static void __init dcache_init(void) 0, 0); d_hash_shift = 32 - d_hash_shift; + + runtime_const_init(shift, d_hash_shift); + runtime_const_init(ptr, dentry_hashtable); } /* SLAB cache for __getname() consumers */ diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild index b20fa25a7e8d..052e5c98c105 100644 --- a/include/asm-generic/Kbuild +++ b/include/asm-generic/Kbuild @@ -46,6 +46,7 @@ mandatory-y += pci.h mandatory-y += percpu.h mandatory-y += pgalloc.h mandatory-y += preempt.h +mandatory-y += runtime-const.h mandatory-y += rwonce.h mandatory-y += sections.h mandatory-y += serial.h diff --git a/include/asm-generic/runtime-const.h b/include/asm-generic/runtime-const.h new file mode 100644 index 000000000000..670499459514 --- /dev/null +++ b/include/asm-generic/runtime-const.h @@ -0,0 +1,15 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_RUNTIME_CONST_H +#define _ASM_RUNTIME_CONST_H + +/* + * This is the fallback for when the architecture doesn't + * support the runtime const operations. + * + * We just use the actual symbols as-is. + */ +#define runtime_const_ptr(sym) (sym) +#define runtime_const_shift_right_32(val, sym) ((u32)(val)>>(sym)) +#define runtime_const_init(type,sym) do { } while (0) + +#endif diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 5703526d6ebf..389a78415b9b 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -944,6 +944,14 @@ #define CON_INITCALL \ BOUNDED_SECTION_POST_LABEL(.con_initcall.init, __con_initcall, _start, _end) +#define RUNTIME_NAME(t,x) runtime_##t##_##x + +#define RUNTIME_CONST(t,x) \ + . = ALIGN(8); \ + RUNTIME_NAME(t,x) : AT(ADDR(RUNTIME_NAME(t,x)) - LOAD_OFFSET) { \ + *(RUNTIME_NAME(t,x)); \ + } + /* Alignment must be consistent with (kunit_suite *) in include/kunit/test.h */ #define KUNIT_TABLE() \ . = ALIGN(8); \ -- 2.45.1.209.gc6f12300df _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel