From patchwork Fri Jul 17 11:10:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 11669925 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 162641392 for ; Fri, 17 Jul 2020 11:15:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F037D2070E for ; Fri, 17 Jul 2020 11:15:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Y/MXDI0t" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726256AbgGQLPL (ORCPT ); Fri, 17 Jul 2020 07:15:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42200 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726550AbgGQLOk (ORCPT ); Fri, 17 Jul 2020 07:14:40 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7945C08C5DD; Fri, 17 Jul 2020 04:14:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-ID:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=gOQYLPqlkXaE5f1BcTQenQfqzoyHPAVuIDnigWhSoRE=; b=Y/MXDI0tbjGV1H6k+/3UUA8Lu5 zcG4hZO3jyz9bLcRi2dIJysN79dO3dnN/J6fbvIK4gxxQiyBlOKQuuCn0E4ddYCbGpPOTo3VVtlki b8indkgQ/FVRbEsFBMBPCZcy3KunV3UanWjKfz3yzA2GvqjF7q6418pyW6NM0aW8XTHtuYN9wNG74 sxLzg+HiCTzpnr/zc2fq3XNvfm31YDJdhEXKopYgPN6tBPKbu/nVWCyNI6khi3A9VUpNMTP2aF7eI 3elFTvXbPIuOkzZ1J7mS4tlF7nVaUtIA8IAJ8rLPZMHlzNolSp/mIGsc5xtO6SOhkwzpM6jWmaDOb UHPdiS5w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jwOJZ-0001Zn-LT; Fri, 17 Jul 2020 11:14:05 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 6F914306CCF; Fri, 17 Jul 2020 13:14:04 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id C0DDF203D4095; Fri, 17 Jul 2020 13:14:02 +0200 (CEST) Message-ID: <20200717111349.708289813@infradead.org> User-Agent: quilt/0.66 Date: Fri, 17 Jul 2020 13:10:11 +0200 From: Peter Zijlstra To: Will Deacon , "Aneesh Kumar K.V" , Andrew Morton , Nick Piggin , Peter Zijlstra Cc: linux-arch@vger.kernel.org, linux-sh@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Yoshinori Sato , Rich Felker , "David S. Miller" , Helge Deller , Geert Uytterhoeven , Paul Burton , Tony Luck , Richard Henderson , Nick Hu , Paul Walmsley , John Paul Adrian Glaubitz , Christoph Hellwig Subject: [PATCH v2 06/11] mips/tlb: Fix __p*_free_tlb() References: <20200717111005.024867618@infradead.org> MIME-Version: 1.0 Sender: linux-sh-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-sh@vger.kernel.org Just like regular pages, page directories need to observe the following order: 1) unhook 2) TLB invalidate 3) free to ensure it is safe against concurrent accesses. MIPS has (thanks to Paul Burton for setting me straight): - HAVE_FAST_GUP, which means we need to consider software walkers (many MIPS also have software TLB-fill, which is a similar software walker). - non-page, page directories, which requires a custom table free. - Mostly IPI-based TLB invalidate, but it wouldn't be MIPS if it didn't also have broadcast TLB invalidate (I6500, GINVT). This means that in generic MIPS needs HAVE_RCU_TABLE_FREE. Signed-off-by: Peter Zijlstra (Intel) --- arch/mips/Kconfig | 1 + arch/mips/include/asm/pgalloc.h | 13 ++++++------- arch/mips/mm/pgtable.c | 34 ++++++++++++++++++++++++++++++++++ 3 files changed, 41 insertions(+), 7 deletions(-) --- a/arch/mips/Kconfig +++ b/arch/mips/Kconfig @@ -84,6 +84,7 @@ config MIPS select HAVE_VIRT_CPU_ACCOUNTING_GEN if 64BIT || !SMP select IRQ_FORCED_THREADING select ISA if EISA + select MMU_GATHER_RCU_TABLE_FREE select MODULES_USE_ELF_REL if MODULES select MODULES_USE_ELF_RELA if MODULES && 64BIT select PERF_USE_VMALLOC --- a/arch/mips/include/asm/pgalloc.h +++ b/arch/mips/include/asm/pgalloc.h @@ -41,6 +41,9 @@ static inline void pud_populate(struct m } #endif +extern void __tlb_remove_table(void *table); +extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int idx); + /* * Initialize a new pgd / pmd table with invalid pointers. */ @@ -52,11 +55,7 @@ static inline void pgd_free(struct mm_st free_pages((unsigned long)pgd, PGD_ORDER); } -#define __pte_free_tlb(tlb,pte,address) \ -do { \ - pgtable_pte_page_dtor(pte); \ - tlb_remove_page((tlb), pte); \ -} while (0) +#define __pte_free_tlb(tlb,pte,address) pgtable_free_tlb((tlb), (pte), 0) #ifndef __PAGETABLE_PMD_FOLDED @@ -75,7 +74,7 @@ static inline void pmd_free(struct mm_st free_pages((unsigned long)pmd, PMD_ORDER); } -#define __pmd_free_tlb(tlb, x, addr) pmd_free((tlb)->mm, x) +#define __pmd_free_tlb(tlb, x, addr) pgtable_free_tlb((tlb), (x), 1) #endif @@ -101,7 +100,7 @@ static inline void p4d_populate(struct m set_p4d(p4d, __p4d((unsigned long)pud)); } -#define __pud_free_tlb(tlb, x, addr) pud_free((tlb)->mm, x) +#define __pud_free_tlb(tlb, x, addr) pgtable_free_tlb((tlb), (x), 2) #endif /* __PAGETABLE_PUD_FOLDED */ --- a/arch/mips/mm/pgtable.c +++ b/arch/mips/mm/pgtable.c @@ -7,6 +7,7 @@ #include #include #include +#include pgd_t *pgd_alloc(struct mm_struct *mm) { @@ -23,3 +24,36 @@ pgd_t *pgd_alloc(struct mm_struct *mm) return ret; } EXPORT_SYMBOL_GPL(pgd_alloc); + +#define TLB_IDX_MASK 0x3 + +void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int idx) +{ + unsigned long pgf = (unsigned long)table; + BUG_ON(idx > TLB_IDX_MASK); + BUG_ON(pgf & TLB_IDX_MASK); + pgf |= idx; + tlb_remove_table(tlb, (void *)pgf); +} + +void __tlb_remove_table(void *table) +{ + void *dir = (void *)((unsigned long)table & ~TLB_IDX_MASK); + int idx = (unsigned long)table & TLB_IDX_MASK; + + switch (idx) { +#ifndef __PAGETABLE_PUD_FOLDED + case 2: /* PUD */ + pud_free(NULL, dir); + break; +#endif +#ifndef __PAGETABLE_PMD_FOLDED + case 1: /* PMD */ + pmd_free(NULL, dir); + break; +#endif + case 0: /* PTE */ + pte_free(NULL, dir); + break; + } +}