From patchwork Sat Jan 16 15:02:53 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Lobakin X-Patchwork-Id: 12024995 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C8F3C433E0 for ; Sat, 16 Jan 2021 18:11:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D5882229C4 for ; Sat, 16 Jan 2021 18:11:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727704AbhAPSLj (ORCPT ); Sat, 16 Jan 2021 13:11:39 -0500 Received: from mail-41104.protonmail.ch ([185.70.41.104]:60772 "EHLO mail-41104.protonmail.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727226AbhAPSLj (ORCPT ); Sat, 16 Jan 2021 13:11:39 -0500 X-Greylist: delayed 4068 seconds by postgrey-1.27 at vger.kernel.org; Sat, 16 Jan 2021 13:11:36 EST Received: from mail-02.mail-europe.com (mail-02.mail-europe.com [51.89.119.103]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by mail-41104.protonmail.ch (Postfix) with ESMTPS id 4281E2004D03 for ; Sat, 16 Jan 2021 15:04:26 +0000 (UTC) Authentication-Results: mail-41104.protonmail.ch; dkim=pass (2048-bit key) header.d=pm.me header.i=@pm.me header.b="SYvyT19s" Date: Sat, 16 Jan 2021 15:02:53 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail; t=1610809382; bh=a71jRuwHG49p+rEiIK2HsboKsC4ZpRrTSk9k/EY42YM=; h=Date:To:From:Cc:Reply-To:Subject:In-Reply-To:References:From; b=SYvyT19s9omQInLAU0wuHr/3iYLXt0OeU6fCva7KLyAs9L93jHWRRf/0RUzvPuQ9r v4ZcmN77a2/0siTs1ShKzLMgUyIrPnglgwrq23KX11k2Jx7LO9T9WtUqes96dw3mru K4cfsO7io96BS1BG4C9kEhsqDp2BESvmNzaVlsX4e8evZtwumm5yzoYTuBy3bpXnte MN9yOCUUfncMAvCyunpW1uf7KyB6Gtf0F7zjiPl8fUehVlj+o16rwJTJaBVx5udixy 0X1j7jBNPSl+ok+AZnekfnGt2JTHQgkDFNn60qN4Ha0XD/XhPpcOAOMFRphATaP9yK 9dCiHZHB9zdGg== To: Thomas Bogendoerfer From: Alexander Lobakin Cc: Nathan Chancellor , Nick Desaulniers , Kees Cook , Andrew Morton , Mike Rapoport , Alexander Lobakin , Jinyang He , linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org Reply-To: Alexander Lobakin Subject: [PATCH mips-next 2/2] MIPS: relocatable: optimize the relocation process Message-ID: <20210116150225.21127-2-alobakin@pm.me> In-Reply-To: <20210116150225.21127-1-alobakin@pm.me> References: <20210116150126.20693-1-alobakin@pm.me> <20210116150225.21127-1-alobakin@pm.me> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org For now, vmlinux relocation functions for relocatable kernel are implemented as an array of handlers of a particular type. Convert that array into a single switch-case function to: - remove unused arguments; - change the return type of simple handlers to void; - remove the array and don't use any data at all; - avoid using indirect calls; - allow the compiler to inline and greatly optimize the relocation function[s]; and also mark do_relocations() and show_kernel_relocation() static as they aren't used anywhere else. The result on MIPS32 R2 with GCC 10.2 -O2 is: scripts/bloat-o-meter -c arch/mips/kernel/__relocate.o arch/mips/kernel/relocate.o add/remove: 0/6 grow/shrink: 1/0 up/down: 356/-640 (-284) Function old new delta relocate_kernel 852 1208 +356 apply_r_mips_32_rel 20 - -20 apply_r_mips_hi16_rel 40 - -40 apply_r_mips_64_rel 44 - -44 apply_r_mips_26_rel 144 - -144 show_kernel_relocation 164 - -164 do_relocations 228 - -228 Total: Before=1780, After=1496, chg -15.96% add/remove: 0/1 grow/shrink: 0/0 up/down: 0/-76 (-76) Data old new delta reloc_handlers_rel 76 - -76 Total: Before=92, After=16, chg -82.61% add/remove: 0/0 grow/shrink: 0/0 up/down: 0/0 (0) RO Data old new delta Total: Before=0, After=0, chg +0.00% All functions were collapsed into the main one, relocate_kernel(). Signed-off-by: Alexander Lobakin --- arch/mips/kernel/relocate.c | 54 ++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 24 deletions(-) diff --git a/arch/mips/kernel/relocate.c b/arch/mips/kernel/relocate.c index 47aeb3350a76..c643c816cbe0 100644 --- a/arch/mips/kernel/relocate.c +++ b/arch/mips/kernel/relocate.c @@ -70,18 +70,14 @@ static void __init sync_icache(void *kbase, unsigned long kernel_length) __sync(); } -static int __init apply_r_mips_64_rel(u32 *loc_orig, u32 *loc_new, long offset) +static void __init apply_r_mips_64_rel(u32 *loc_new, long offset) { *(u64 *)loc_new += offset; - - return 0; } -static int __init apply_r_mips_32_rel(u32 *loc_orig, u32 *loc_new, long offset) +static void __init apply_r_mips_32_rel(u32 *loc_new, long offset) { *loc_new += offset; - - return 0; } static int __init apply_r_mips_26_rel(u32 *loc_orig, u32 *loc_new, long offset) @@ -114,7 +110,8 @@ static int __init apply_r_mips_26_rel(u32 *loc_orig, u32 *loc_new, long offset) } -static int __init apply_r_mips_hi16_rel(u32 *loc_orig, u32 *loc_new, long offset) +static void __init apply_r_mips_hi16_rel(u32 *loc_orig, u32 *loc_new, + long offset) { unsigned long insn = *loc_orig; unsigned long target = (insn & 0xffff) << 16; /* high 16bits of target */ @@ -122,17 +119,33 @@ static int __init apply_r_mips_hi16_rel(u32 *loc_orig, u32 *loc_new, long offset target += offset; *loc_new = (insn & ~0xffff) | ((target >> 16) & 0xffff); - return 0; } -static int (*reloc_handlers_rel[]) (u32 *, u32 *, long) __initdata = { - [R_MIPS_64] = apply_r_mips_64_rel, - [R_MIPS_32] = apply_r_mips_32_rel, - [R_MIPS_26] = apply_r_mips_26_rel, - [R_MIPS_HI16] = apply_r_mips_hi16_rel, -}; +static int __init reloc_handler(u32 type, u32 *loc_orig, u32 *loc_new, + long offset) +{ + switch (type) { + case R_MIPS_64: + apply_r_mips_64_rel(loc_new, offset); + break; + case R_MIPS_32: + apply_r_mips_32_rel(loc_new, offset); + break; + case R_MIPS_26: + return apply_r_mips_26_rel(loc_orig, loc_new, offset); + case R_MIPS_HI16: + apply_r_mips_hi16_rel(loc_orig, loc_new, offset); + break; + default: + pr_err("Unhandled relocation type %d at 0x%pK\n", type, + loc_orig); + return -ENOEXEC; + } -int __init do_relocations(void *kbase_old, void *kbase_new, long offset) + return 0; +} + +static int __init do_relocations(void *kbase_old, void *kbase_new, long offset) { u32 *r; u32 *loc_orig; @@ -149,14 +162,7 @@ int __init do_relocations(void *kbase_old, void *kbase_new, long offset) loc_orig = kbase_old + ((*r & 0x00ffffff) << 2); loc_new = RELOCATED(loc_orig); - if (reloc_handlers_rel[type] == NULL) { - /* Unsupported relocation */ - pr_err("Unhandled relocation type %d at 0x%pK\n", - type, loc_orig); - return -ENOEXEC; - } - - res = reloc_handlers_rel[type](loc_orig, loc_new, offset); + res = reloc_handler(type, loc_orig, loc_new, offset); if (res) return res; } @@ -412,7 +418,7 @@ void *__init relocate_kernel(void) /* * Show relocation information on panic. */ -void show_kernel_relocation(const char *level) +static void show_kernel_relocation(const char *level) { unsigned long offset;