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 X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 CCECDC43214 for ; Thu, 12 Aug 2021 23:38:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A920F610A4 for ; Thu, 12 Aug 2021 23:38:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238038AbhHLXiZ (ORCPT ); Thu, 12 Aug 2021 19:38:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:48642 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233854AbhHLXiX (ORCPT ); Thu, 12 Aug 2021 19:38:23 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 784C160EE2; Thu, 12 Aug 2021 23:37:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628811477; bh=iGK8PU/tmDB3AhUhP6XkaxS4+cLDTMouE860/hGTGtk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kmHBNkN4z+GRV91Y98Q1O5gj2BS2hSbsyBU1Rx42aTRA4/P9lVbJnrvjY5Eb8eMnv 0pqmEK6WYQTWwCKA5BnsmlHJ2HO7Vp7NLGBqchILI58wf97BmDY4YcH8upSiFpcwB9 MFvVipwSqrmvgtXplIi9CggjYMAbUEIeoOePlmwCC7EOLUYS87fEoGbvCBaDAfdTuC mDstBKy/+HjdigeqxLcTwOd6iP0OizA7OhuBZ6JW4YQxAIFxMSeoFPgheg066VCrGI +wwmROgzgSqQvsTRy6KYUPX1JPktQyDyUHbcmqLvoyW7bQBvvJK6O1Vnb0qUTFJeN7 wPm/0VpPpF59Q== From: Vineet Gupta To: linux-snps-arc@lists.infradead.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Anshuman Khandual , Mike Rapoport , Vineet Gupta Subject: [PATCH v2 01/19] ARC: mm: use SCRATCH_DATA0 register for caching pgdir in ARCv2 only Date: Thu, 12 Aug 2021 16:37:35 -0700 Message-Id: <20210812233753.104217-2-vgupta@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210812233753.104217-1-vgupta@kernel.org> References: <20210812233753.104217-1-vgupta@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org MMU SCRATCH_DATA0 register is intended to cache task pgd. However in ARC700 SMP port, it has to be repurposed for reentrant interrupt handling, while UP port doesn't. We currently ahandle boe usecases using a fabricated which has usual issues of dependency nesting and ugliness. So clean this up: for ARC700 don't use to cache pgd (even in UP) and do the opposite for ARCv2. And while here, switch to canonical pgd_offset(). Signed-off-by: Vineet Gupta --- arch/arc/include/asm/entry-compact.h | 8 -------- arch/arc/include/asm/mmu.h | 4 ---- arch/arc/include/asm/mmu_context.h | 2 +- arch/arc/include/asm/pgtable.h | 23 ----------------------- arch/arc/mm/fault.c | 2 +- arch/arc/mm/tlb.c | 4 ++-- arch/arc/mm/tlbex.S | 2 +- 7 files changed, 5 insertions(+), 40 deletions(-) diff --git a/arch/arc/include/asm/entry-compact.h b/arch/arc/include/asm/entry-compact.h index 6dbf5cecc8cc..5aab4f93ab8a 100644 --- a/arch/arc/include/asm/entry-compact.h +++ b/arch/arc/include/asm/entry-compact.h @@ -126,19 +126,11 @@ * to be saved again on kernel mode stack, as part of pt_regs. *-------------------------------------------------------------*/ .macro PROLOG_FREEUP_REG reg, mem -#ifndef ARC_USE_SCRATCH_REG - sr \reg, [ARC_REG_SCRATCH_DATA0] -#else st \reg, [\mem] -#endif .endm .macro PROLOG_RESTORE_REG reg, mem -#ifndef ARC_USE_SCRATCH_REG - lr \reg, [ARC_REG_SCRATCH_DATA0] -#else ld \reg, [\mem] -#endif .endm /*-------------------------------------------------------------- diff --git a/arch/arc/include/asm/mmu.h b/arch/arc/include/asm/mmu.h index a81d1975866a..4065335a7922 100644 --- a/arch/arc/include/asm/mmu.h +++ b/arch/arc/include/asm/mmu.h @@ -31,10 +31,6 @@ #define ARC_REG_SCRATCH_DATA0 0x46c #endif -#if defined(CONFIG_ISA_ARCV2) || !defined(CONFIG_SMP) -#define ARC_USE_SCRATCH_REG -#endif - /* Bits in MMU PID register */ #define __TLB_ENABLE (1 << 31) #define __PROG_ENABLE (1 << 30) diff --git a/arch/arc/include/asm/mmu_context.h b/arch/arc/include/asm/mmu_context.h index df164066e172..49318a126879 100644 --- a/arch/arc/include/asm/mmu_context.h +++ b/arch/arc/include/asm/mmu_context.h @@ -146,7 +146,7 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, */ cpumask_set_cpu(cpu, mm_cpumask(next)); -#ifdef ARC_USE_SCRATCH_REG +#ifdef CONFIG_ISA_ARCV2 /* PGD cached in MMU reg to avoid 3 mem lookups: task->mm->pgd */ write_aux_reg(ARC_REG_SCRATCH_DATA0, next->pgd); #endif diff --git a/arch/arc/include/asm/pgtable.h b/arch/arc/include/asm/pgtable.h index 0c3e220bd2b4..80b57c14b430 100644 --- a/arch/arc/include/asm/pgtable.h +++ b/arch/arc/include/asm/pgtable.h @@ -284,29 +284,6 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, set_pte(ptep, pteval); } -/* - * Macro to quickly access the PGD entry, utlising the fact that some - * arch may cache the pointer to Page Directory of "current" task - * in a MMU register - * - * Thus task->mm->pgd (3 pointer dereferences, cache misses etc simply - * becomes read a register - * - * ********CAUTION*******: - * Kernel code might be dealing with some mm_struct of NON "current" - * Thus use this macro only when you are certain that "current" is current - * e.g. when dealing with signal frame setup code etc - */ -#ifdef ARC_USE_SCRATCH_REG -#define pgd_offset_fast(mm, addr) \ -({ \ - pgd_t *pgd_base = (pgd_t *) read_aux_reg(ARC_REG_SCRATCH_DATA0); \ - pgd_base + pgd_index(addr); \ -}) -#else -#define pgd_offset_fast(mm, addr) pgd_offset(mm, addr) -#endif - extern pgd_t swapper_pg_dir[] __aligned(PAGE_SIZE); void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep); diff --git a/arch/arc/mm/fault.c b/arch/arc/mm/fault.c index f5657cb68e4f..41f154320964 100644 --- a/arch/arc/mm/fault.c +++ b/arch/arc/mm/fault.c @@ -33,7 +33,7 @@ noinline static int handle_kernel_vaddr_fault(unsigned long address) pud_t *pud, *pud_k; pmd_t *pmd, *pmd_k; - pgd = pgd_offset_fast(current->active_mm, address); + pgd = pgd_offset(current->active_mm, address); pgd_k = pgd_offset_k(address); if (!pgd_present(*pgd_k)) diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c index 8696829d37c0..349fb7a75d1d 100644 --- a/arch/arc/mm/tlb.c +++ b/arch/arc/mm/tlb.c @@ -719,8 +719,8 @@ void arc_mmu_init(void) /* Enable the MMU */ write_aux_reg(ARC_REG_PID, MMU_ENABLE); - /* In smp we use this reg for interrupt 1 scratch */ -#ifdef ARC_USE_SCRATCH_REG + /* In arc700/smp needed for re-entrant interrupt handling */ +#ifdef CONFIG_ISA_ARCV2 /* swapper_pg_dir is the pgd for the kernel, used by vmalloc */ write_aux_reg(ARC_REG_SCRATCH_DATA0, swapper_pg_dir); #endif diff --git a/arch/arc/mm/tlbex.S b/arch/arc/mm/tlbex.S index 96c3a5de9dd4..bcd2909c691f 100644 --- a/arch/arc/mm/tlbex.S +++ b/arch/arc/mm/tlbex.S @@ -202,7 +202,7 @@ ex_saved_reg1: lr r2, [efa] -#ifdef ARC_USE_SCRATCH_REG +#ifdef CONFIG_ISA_ARCV2 lr r1, [ARC_REG_SCRATCH_DATA0] ; current pgd #else GET_CURR_TASK_ON_CPU r1 -- 2.25.1