From patchwork Mon Apr 11 09:47:56 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ard Biesheuvel X-Patchwork-Id: 561273 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3550EC433EF for ; Mon, 11 Apr 2022 09:51:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344751AbiDKJw3 (ORCPT ); Mon, 11 Apr 2022 05:52:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344787AbiDKJvv (ORCPT ); Mon, 11 Apr 2022 05:51:51 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 427484198E for ; Mon, 11 Apr 2022 02:48:52 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id EA9C4B81199 for ; Mon, 11 Apr 2022 09:48:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A5156C385AF; Mon, 11 Apr 2022 09:48:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1649670527; bh=nnF7M7PcH7AGljFxhk+1kS0DWN9btzeG7hbQYqOxYrQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nHn/66Dcqkmue8O9qjtSGu/PRWu/RIuh+0yc8Mya99Ex6qDyj1+ooe9IUIMalhi1y zQkOcoDq2TC+A9FcwraXhNmBjLP8+rEw0sLTYbtvPsIR9iEvG1AcyqsL9St/aRIPTt q6wMHskOTTYf6LYOtTfMwwb4pi/4ZNgU9wEtL2HLhX1+/hfU9I0OckQJbeqV/9Oo1t noH2k88MIcraef6yNFs+m0rsk1NV307A3nACrEQ0XyafCXIRX/ZzyDR4W0tbhwiaIc RVc6QaYmdesSfNAJNlNyNM5HOh2vYSEGFmgprRlzrihOqtgYpswkIepHue4cQIEqMn BRhmgi/C2Nd3g== From: Ard Biesheuvel To: linux-arm-kernel@lists.infradead.org Cc: linux-efi@vger.kernel.org, Ard Biesheuvel , Marc Zyngier , Will Deacon , Mark Rutland , Kees Cook , Catalin Marinas , Mark Brown Subject: [PATCH v3 02/30] arm64: mm: make vabits_actual a build time constant if possible Date: Mon, 11 Apr 2022 11:47:56 +0200 Message-Id: <20220411094824.4176877-3-ardb@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220411094824.4176877-1-ardb@kernel.org> References: <20220411094824.4176877-1-ardb@kernel.org> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3103; h=from:subject; bh=nnF7M7PcH7AGljFxhk+1kS0DWN9btzeG7hbQYqOxYrQ=; b=owEB7QES/pANAwAKAcNPIjmS2Y8kAcsmYgBiU/k49z3HshtZskOsuOPow52IVZV3y9S8oWY9dDxR 1KfkHXKJAbMEAAEKAB0WIQT72WJ8QGnJQhU3VynDTyI5ktmPJAUCYlP5OAAKCRDDTyI5ktmPJE04C/ 42FMvcJRjeULojkYUP5mu6KQ5dvmOxDO5LCDKnAogTTJ0wyfSG7RdIr5MMvr2SqEGlYBwuqUTAcLzX zFMAat4VLbUZj3sJgKQBWpML3WCv8ZTqj9ig3eQwtG/+uDiPcw0toKxfIDg9lQYfhAUA0dGcNh32Oj aNzEs4+cja+CztoE9vpJaBWkruYYrwhcN3VEH7e9cvunA6ZVi1kAtFZzhWrPfrsHaB20f9yBkEhUWN N6WJYt/F/PH3AePPGCOyasLu9YsASaUU+gZ6IM/puZ/SnZcXcfa/bD8jiaHXJA+1lVdlQWZ2a6rbpx uT0ataOYqe18w4Qeub8r8VMQSJHC3V/7EBujcfVAqrrnqPrN2MTWqH8dEGxcVFMdQKPXVq7DjJWAgQ L+u9y/9bbpgs+tB1J0x19xrcAJMRAvbvn9rvnN4SrR9uNXSSAtUizMuflfWsmTKM6162/9ue4nJQNP rmBWgUdUtzg4yEoJKnS/S8thdSt4dUFD8lEafCv/27i9Q= X-Developer-Key: i=ardb@kernel.org; a=openpgp; fpr=F43D03328115A198C90016883D200E9CA6329909 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Currently, we only support 52-bit virtual addressing on 64k pages configurations, and in all other cases, vabits_actual is guaranteed to equal VA_BITS (== VA_BITS_MIN). So get rid of the variable entirely in that case. While at it, move the assignment out of the asm entry code - it has no need to be there. Signed-off-by: Ard Biesheuvel --- arch/arm64/include/asm/memory.h | 4 ++++ arch/arm64/kernel/head.S | 15 +-------------- arch/arm64/mm/mmu.c | 15 ++++++++++++++- 3 files changed, 19 insertions(+), 15 deletions(-) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index 0af70d9abede..c751cd9b94f8 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -174,7 +174,11 @@ #include #include +#if VA_BITS > 48 extern u64 vabits_actual; +#else +#define vabits_actual ((u64)VA_BITS) +#endif extern s64 memstart_addr; /* PHYS_OFFSET - the physical address of the start of memory. */ diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 1cdecce552bb..dc07858eb673 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -293,19 +293,6 @@ SYM_FUNC_START_LOCAL(__create_page_tables) adrp x0, idmap_pg_dir adrp x3, __idmap_text_start // __pa(__idmap_text_start) -#ifdef CONFIG_ARM64_VA_BITS_52 - mrs_s x6, SYS_ID_AA64MMFR2_EL1 - and x6, x6, #(0xf << ID_AA64MMFR2_LVA_SHIFT) - mov x5, #52 - cbnz x6, 1f -#endif - mov x5, #VA_BITS_MIN -1: - adr_l x6, vabits_actual - str x5, [x6] - dmb sy - dc ivac, x6 // Invalidate potentially stale cache line - /* * VA_BITS may be too small to allow for an ID mapping to be created * that covers system RAM if that is located sufficiently high in the @@ -713,7 +700,7 @@ SYM_FUNC_START(__enable_mmu) SYM_FUNC_END(__enable_mmu) SYM_FUNC_START(__cpu_secondary_check52bitva) -#ifdef CONFIG_ARM64_VA_BITS_52 +#if VA_BITS > 48 ldr_l x0, vabits_actual cmp x0, #52 b.ne 2f diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index fde2b326419a..2018e75974ca 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -46,8 +46,10 @@ u64 idmap_t0sz = TCR_T0SZ(VA_BITS_MIN); u64 idmap_ptrs_per_pgd = PTRS_PER_PGD; -u64 __section(".mmuoff.data.write") vabits_actual; +#if VA_BITS > 48 +u64 vabits_actual __ro_after_init = VA_BITS_MIN; EXPORT_SYMBOL(vabits_actual); +#endif u64 kimage_vaddr __ro_after_init = (u64)&_text; EXPORT_SYMBOL(kimage_vaddr); @@ -769,6 +771,17 @@ void __init paging_init(void) { pgd_t *pgdp = pgd_set_fixmap(__pa_symbol(swapper_pg_dir)); +#if VA_BITS > 48 + if (cpuid_feature_extract_unsigned_field( + read_sysreg_s(SYS_ID_AA64MMFR2_EL1), + ID_AA64MMFR2_LVA_SHIFT)) + vabits_actual = VA_BITS; + + /* make the variable visible to secondaries with the MMU off */ + dcache_clean_inval_poc((u64)&vabits_actual, + (u64)&vabits_actual + sizeof(vabits_actual)); +#endif + map_kernel(pgdp); map_mem(pgdp);