From patchwork Fri Jul 14 16:54:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Charlie Jenkins X-Patchwork-Id: 13313856 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 2995CC001B0 for ; Fri, 14 Jul 2023 16:56:09 +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=IR8QF9NakA6JGRIHNDe2CSDJn5PSYZzlsvxi7adsemQ=; b=XaTBVc7nmu+5Z1 KZUXvj7mUsEv1W1SXoDlRV8lmo2qpKQB01dPCj69d7dctOQ99/tmxZYiUDdz573idvwhoR/rQqNqy +CLKQwniY/XbM8KbIAWAc9yxpApY66oeD6zRsUax5gQli9VYoRWdptCBopKMdp8dTS2akKf31P97j ybGS7kh+j28LClY2d4AP3OSGn/a4/vV5hLtSI/NRnycP/XXJ8YSubeHqvW0j0OtglUiNRV3Ce+gfd f0ufmTDi09bAkH7Cl85VNk0KTHHaZhN5lXw5Nx7GpJ6ZK9wIp5TZu9WSKyomtIGUAJMHsiYXHeAT2 QfLPHLakH/0udSPPVWEQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qKM5M-006hYq-32; Fri, 14 Jul 2023 16:56:04 +0000 Received: from mail-pl1-x62b.google.com ([2607:f8b0:4864:20::62b]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qKM5J-006hT8-0e for linux-riscv@lists.infradead.org; Fri, 14 Jul 2023 16:56:03 +0000 Received: by mail-pl1-x62b.google.com with SMTP id d9443c01a7336-1b8b318c5cfso16125905ad.1 for ; Fri, 14 Jul 2023 09:55:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1689353756; x=1689958556; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=GPykY2M+iBxgnfF3tLWI+OoGLznOreuMykVpzGzQM9M=; b=azZgM6AeXJmCDZjMcCvpOfGXYgGHNCAAPxNXV/uspW22hdXFA8MPuhazigJp0SbCJS 8tx99+fKEiCI1J31eTc92ZC6uoPPCBIEWn85byNxcOtC1TFjaiCPLzerJL2mujp5NPfe tcQkn3YgmIUEukMMAzAC+lS3FOWn7t2WGAWBaQbDxJ7F45liY/U120jgK6dSI82+FFGs cKJ+9Jrz+roxSXvXdpvhnZk6b+RrV4+d7dKzXAd2+9hgjhFiAUVDWsWNow2J0tlknkrp iXnusxEZA6uchq9Zw64fmDJgWEo8vBJlNrD/7xa/Q9WtmFrZU5dJZpb8ZTdqxtsXQj5e IR/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689353756; x=1689958556; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=GPykY2M+iBxgnfF3tLWI+OoGLznOreuMykVpzGzQM9M=; b=NjNzf72Reqid6rP+ucTydxlhhkIZh/Io5O1bvWQzGJDBEfeSzJYZCtaf+xZ3b3KrK1 fub84rF05AIwk0ScEV472jErnDBfD5U94UxnGldUHPQ8VEmUPptQWn2onIIlijlL3cJk oHfSht7jHKBOkIdAle2+RarEb1bBPmr66nWkEURNjNUQvSvuZTlnCqyPO7b1CH5wwEBJ GYyF97HsVIuQgxJU8XKtPxKmoSdXpkoHWMr4QqwjC+Tu0ncg9C4jF8x+Xni5ZEOvaAcE FPOSjWIuujepxHNL0SHZEMcMNI0B3THsncOLTfJodb3tlUZAHVG01dQsILehdvaQff1a O89w== X-Gm-Message-State: ABy/qLaoKgY4mz1QpkY8wC59temqz93btK8BTVp3Zcuxkv2MvnRHbQFD snpp/ClSW+ykZJ8u7eWEZzQaTMxpeyMi6sDTIQE= X-Google-Smtp-Source: APBJJlEDGSDEGOdKDXhmmtq/RjWdYGrULh2CJQYPjEZOW+WH3IqJ8qF98vsQhnn68tlVv8hSzAc2BA== X-Received: by 2002:a17:902:e5c2:b0:1b8:4f92:565e with SMTP id u2-20020a170902e5c200b001b84f92565emr5737152plf.21.1689353756696; Fri, 14 Jul 2023 09:55:56 -0700 (PDT) Received: from charlie.ba.rivosinc.com ([66.220.2.162]) by smtp.gmail.com with ESMTPSA id s8-20020a170902b18800b001b694140d96sm8008081plr.170.2023.07.14.09.55.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Jul 2023 09:55:56 -0700 (PDT) From: Charlie Jenkins To: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: charlie@rivosinc.com, conor@kernel.org, paul.walmsley@sifive.com, palmer@rivosinc.com, aou@eecs.berkeley.edu, anup@brainfault.org, konstantin@linuxfoundation.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, mick@ics.forth.gr, jrtc27@jrtc27.com, rdunlap@infradead.org, alexghiti@rivosinc.com Subject: [PATCH v6 1/4] RISC-V: mm: Restrict address space for sv39,sv48,sv57 Date: Fri, 14 Jul 2023 09:54:49 -0700 Message-ID: <20230714165508.94561-2-charlie@rivosinc.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230714165508.94561-1-charlie@rivosinc.com> References: <20230714165508.94561-1-charlie@rivosinc.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230714_095601_236530_1B688F16 X-CRM114-Status: GOOD ( 15.03 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Make sv48 the default address space for mmap as some applications currently depend on this assumption. A hint address passed to mmap will cause the largest address space that fits entirely into the hint to be used. If the hint is less than or equal to 1<<38, an sv39 address will be used. An exception is that if the hint address is 0, then a sv48 address will be used. After an address space is completely full, the next smallest address space will be used. Signed-off-by: Charlie Jenkins --- arch/riscv/include/asm/elf.h | 2 +- arch/riscv/include/asm/pgtable.h | 12 +++++++- arch/riscv/include/asm/processor.h | 46 +++++++++++++++++++++++++----- 3 files changed, 51 insertions(+), 9 deletions(-) diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index c24280774caf..5d3368d5585c 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -49,7 +49,7 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr); * the loader. We need to make sure that it is out of the way of the program * that it will "exec", and that there is sufficient room for the brk. */ -#define ELF_ET_DYN_BASE ((TASK_SIZE / 3) * 2) +#define ELF_ET_DYN_BASE ((DEFAULT_MAP_WINDOW / 3) * 2) #ifdef CONFIG_64BIT #ifdef CONFIG_COMPAT diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 75970ee2bda2..e13f5872bfe9 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -63,12 +63,22 @@ * position vmemmap directly below the VMALLOC region. */ #ifdef CONFIG_64BIT +#define VA_BITS_SV39 39 +#define VA_BITS_SV48 48 +#define VA_BITS_SV57 57 + +#define VA_USER_SV39 (UL(1) << (VA_BITS_SV39 - 1)) +#define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1)) +#define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1)) + #define VA_BITS (pgtable_l5_enabled ? \ - 57 : (pgtable_l4_enabled ? 48 : 39)) + VA_BITS_SV57 : (pgtable_l4_enabled ? VA_BITS_SV48 : VA_BITS_SV39)) #else #define VA_BITS 32 #endif +#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS) + #define VMEMMAP_SHIFT \ (VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT) #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT) diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index c950a8d9edef..14a5396eed3d 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -13,20 +13,52 @@ #include -/* - * This decides where the kernel will search for a free chunk of vm - * space during mmap's. - */ -#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3) - -#define STACK_TOP TASK_SIZE #ifdef CONFIG_64BIT +#define DEFAULT_MAP_WINDOW (UL(1) << (MMAP_VA_BITS - 1)) #define STACK_TOP_MAX TASK_SIZE_64 + +#define arch_get_mmap_end(addr, len, flags) \ +({ \ + unsigned long mmap_end; \ + if ((addr) >= VA_USER_SV57) \ + mmap_end = STACK_TOP_MAX; \ + else if ((((addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \ + mmap_end = VA_USER_SV48; \ + else if ((addr) == 0) \ + mmap_end = DEFAULT_MAP_WINDOW; \ + else \ + mmap_end = VA_USER_SV39; \ + mmap_end; \ +}) + +#define arch_get_mmap_base(addr, base) \ +({ \ + unsigned long mmap_base; \ + if (((addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \ + mmap_base = (base) + (VA_USER_SV57 - DEFAULT_MAP_WINDOW); \ + else if ((((addr) >= VA_USER_SV48)) && (VA_BITS >= VA_BITS_SV48)) \ + mmap_base = (base) + (VA_USER_SV48 - DEFAULT_MAP_WINDOW); \ + else if ((addr) == 0) \ + mmap_base = (base); \ + else \ + mmap_base = (base) + (VA_USER_SV39 - DEFAULT_MAP_WINDOW); \ + mmap_base; \ +}) + #else +#define DEFAULT_MAP_WINDOW TASK_SIZE #define STACK_TOP_MAX TASK_SIZE #endif #define STACK_ALIGN 16 +#define STACK_TOP DEFAULT_MAP_WINDOW + +/* + * This decides where the kernel will search for a free chunk of vm + * space during mmap's. + */ +#define TASK_UNMAPPED_BASE PAGE_ALIGN(DEFAULT_MAP_WINDOW / 3) + #ifndef __ASSEMBLY__ struct task_struct; From patchwork Fri Jul 14 16:54:50 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Charlie Jenkins X-Patchwork-Id: 13313859 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 EE7CFC001DE for ; Fri, 14 Jul 2023 16:56:13 +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=zz2Js0tkfnGQ4LjPy/0pjCvuNq8/ru9pXMHi1ufuvCY=; b=XvKp2OyWYgo7Z7 z347b/AnduTjHZ3hic515kx3SxiKbj1zYNl9hg89OsNRiovwPuRZVALdTVKgfPqDSUX1mjPHTHHVi CRczilykSyvNS+AXy1LUe26Tieq/e6WMHQ+CaHzlmu8vJwiyRO2YM0PmM6JXqcyVYk68cMpnSy8DX Tq7nMg4kejFZCKG5bR4dxkbbDF/dOzIesSK56lGqzI4R2kXpEPe6f903fzDZ5dDtAqUYvzdvNCBWT 8yPLv/fX4eKk3gHE5FLL/OdUCEO3DGgRbMLnwTjql31OGp6VQs1GbF1jWa/QjMnkpXVs83wGfwK8g rVrrJ+oPKmt+HxeLjiuw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qKM5R-006hd3-2f; Fri, 14 Jul 2023 16:56:09 +0000 Received: from mail-pl1-x62d.google.com ([2607:f8b0:4864:20::62d]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qKM5K-006hTQ-3D for linux-riscv@lists.infradead.org; Fri, 14 Jul 2023 16:56:06 +0000 Received: by mail-pl1-x62d.google.com with SMTP id d9443c01a7336-1b89e10d356so13568555ad.3 for ; Fri, 14 Jul 2023 09:55:58 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1689353758; x=1689958558; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=fFZ0EGHA/E167mwLb87wWH3iE0UjDp5JHbGLXoRkRqA=; b=zn1whIzFksbFhXTqO34vKblrmsHff/17GQr3bYOcezH28cQyvPFNhQUxXa2sAPmMS1 1WI0ByZzMGBTJbHi/dO8HxLEz8TgAL8vMPlN/S9Zlsd9+L0JcfDsc/ikDWbR3lPJjq17 adM7DlbZeACS2bGGGK5LbhAjLUMSTXTi7aBNuf6MnFpcIurtWpRgYjYi7jf1WGpkUtp2 zscz6fUP32Fhq928O1gU6GgR6VfLSBJ1gX7eP4OWmx7it+jF6Ll0l5TqyoxCdBmQtFi1 C+Hb6hQIy3kY2fVb4xvTy0IgnX2o2sglJ+bfpV+gz1AiXbrLwVBWPm4t4lez/7lvKMfS EcJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689353758; x=1689958558; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=fFZ0EGHA/E167mwLb87wWH3iE0UjDp5JHbGLXoRkRqA=; b=hToEaK18wabpEU7dtsXrHW7299iYacSR4xe4H/1Qn4ikBYlIn0FP3XgNwo4sxSFaNo Q2y/0N84tsRCZq7QmzZbiLOhpO3SkKWu2Mn304VWWpVH6npbcfoA66VELmBIkbXWtJMY 4Ys8B4EImDPQWRHF8P0eJKsAvYAgjDNj2C1YsFQdIEjqqP93nol65qy19h6z7SUVRh+s 5QEnt7zHEIjyUwxkJ2oqQ3zi/Id0m1oxFvwOqB2tcri/qHIzNyegxfgRpmsGHhdVNL/I WteCbpJAO2TTFmeQ+tG1UV+5aErC7aJ02mzdxKRmmPyzZKQAzo16wqp7qD18rLrrT6o/ rvwA== X-Gm-Message-State: ABy/qLZHmpy8OegVvHyiCiePMvGb/2rdQyP4jd0Afmmb2G0hg75IY1vQ fDuPZKMuHmKjtKJA/1zusMQ2roBSYDb8oxXjA14= X-Google-Smtp-Source: APBJJlHqhS0uCuOyMfhOId30Fk2bIt7sCu1bJXWOcbA6EcvHwaFt3gMEbaHPbnOB7iiOK1Fg3tgsWA== X-Received: by 2002:a17:902:bd94:b0:1b8:1e05:ed09 with SMTP id q20-20020a170902bd9400b001b81e05ed09mr3727099pls.36.1689353758143; Fri, 14 Jul 2023 09:55:58 -0700 (PDT) Received: from charlie.ba.rivosinc.com ([66.220.2.162]) by smtp.gmail.com with ESMTPSA id s8-20020a170902b18800b001b694140d96sm8008081plr.170.2023.07.14.09.55.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Jul 2023 09:55:57 -0700 (PDT) From: Charlie Jenkins To: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: charlie@rivosinc.com, conor@kernel.org, paul.walmsley@sifive.com, palmer@rivosinc.com, aou@eecs.berkeley.edu, anup@brainfault.org, konstantin@linuxfoundation.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, mick@ics.forth.gr, jrtc27@jrtc27.com, rdunlap@infradead.org, alexghiti@rivosinc.com Subject: [PATCH v6 2/4] RISC-V: mm: Add tests for RISC-V mm Date: Fri, 14 Jul 2023 09:54:50 -0700 Message-ID: <20230714165508.94561-3-charlie@rivosinc.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230714165508.94561-1-charlie@rivosinc.com> References: <20230714165508.94561-1-charlie@rivosinc.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230714_095603_059332_A80EFF5A X-CRM114-Status: GOOD ( 16.57 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Add tests that enforce mmap hint address behavior. mmap should default to sv48. mmap will provide an address at the highest address space that can fit into the hint address, unless the hint address is less than sv39 and not 0, then it will return a sv39 address. In addition, ensure that rlimit changes do not cause mmap to fail. Signed-off-by: Charlie Jenkins --- tools/testing/selftests/riscv/Makefile | 2 +- tools/testing/selftests/riscv/mm/.gitignore | 1 + tools/testing/selftests/riscv/mm/Makefile | 21 +++ .../selftests/riscv/mm/testcases/mmap.c | 133 ++++++++++++++++++ 4 files changed, 156 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/riscv/mm/.gitignore create mode 100644 tools/testing/selftests/riscv/mm/Makefile create mode 100644 tools/testing/selftests/riscv/mm/testcases/mmap.c diff --git a/tools/testing/selftests/riscv/Makefile b/tools/testing/selftests/riscv/Makefile index 9dd629cc86aa..1b79da90396e 100644 --- a/tools/testing/selftests/riscv/Makefile +++ b/tools/testing/selftests/riscv/Makefile @@ -5,7 +5,7 @@ ARCH ?= $(shell uname -m 2>/dev/null || echo not) ifneq (,$(filter $(ARCH),riscv)) -RISCV_SUBTARGETS ?= hwprobe vector +RISCV_SUBTARGETS ?= hwprobe vector mm else RISCV_SUBTARGETS := endif diff --git a/tools/testing/selftests/riscv/mm/.gitignore b/tools/testing/selftests/riscv/mm/.gitignore new file mode 100644 index 000000000000..9a6f303edcd3 --- /dev/null +++ b/tools/testing/selftests/riscv/mm/.gitignore @@ -0,0 +1 @@ +mmap diff --git a/tools/testing/selftests/riscv/mm/Makefile b/tools/testing/selftests/riscv/mm/Makefile new file mode 100644 index 000000000000..cf68e63e7495 --- /dev/null +++ b/tools/testing/selftests/riscv/mm/Makefile @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0 +# Originally tools/testing/selftests/arm64/signal + +# Additional include paths needed by kselftest.h and local headers +CFLAGS += -D_GNU_SOURCE -std=gnu99 -I. + +SRCS := $(filter-out testcases/testcases.c,$(wildcard testcases/*.c)) +PROGS := $(patsubst %.c,%,$(SRCS)) + +# Generated binaries to be installed by top KSFT script +TEST_GEN_PROGS := $(notdir $(PROGS)) + +# Get Kernel headers installed and use them. + +# Including KSFT lib.mk here will also mangle the TEST_GEN_PROGS list +# to account for any OUTPUT target-dirs optionally provided by +# the toplevel makefile +include ../../lib.mk + +$(TEST_GEN_PROGS): $(PROGS) + cp $(PROGS) $(OUTPUT)/ diff --git a/tools/testing/selftests/riscv/mm/testcases/mmap.c b/tools/testing/selftests/riscv/mm/testcases/mmap.c new file mode 100644 index 000000000000..d8e751f7b8c9 --- /dev/null +++ b/tools/testing/selftests/riscv/mm/testcases/mmap.c @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include + +#include "../../kselftest_harness.h" +struct addresses { + int *no_hint; + int *on_37_addr; + int *on_38_addr; + int *on_46_addr; + int *on_47_addr; + int *on_55_addr; + int *on_56_addr; +}; + +void do_mmaps(struct addresses *mmap_addresses) +{ + // Place all of the hint addresses on the boundaries of mmap + // sv39, sv48, sv57 + // User addresses end at 1<<38, 1<<47, 1<<56 respectively + void *on_37_bits = (void *)(1UL << 37); + void *on_38_bits = (void *)(1UL << 38); + void *on_46_bits = (void *)(1UL << 46); + void *on_47_bits = (void *)(1UL << 47); + void *on_55_bits = (void *)(1UL << 55); + void *on_56_bits = (void *)(1UL << 56); + + int prot = PROT_READ | PROT_WRITE; + int flags = MAP_PRIVATE | MAP_ANONYMOUS; + + mmap_addresses->no_hint = + mmap(NULL, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_37_addr = + mmap(on_37_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_38_addr = + mmap(on_38_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_46_addr = + mmap(on_46_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_47_addr = + mmap(on_47_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_55_addr = + mmap(on_55_bits, 5 * sizeof(int), prot, flags, 0, 0); + mmap_addresses->on_56_addr = + mmap(on_56_bits, 5 * sizeof(int), prot, flags, 0, 0); +} + +TEST(default_rlimit) +{ +// Only works on 64 bit +#if __riscv_xlen == 64 + struct addresses mmap_addresses; + + do_mmaps(&mmap_addresses); + + EXPECT_NE(mmap_addresses.no_hint, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_37_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_38_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_46_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_47_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_55_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_56_addr, MAP_FAILED); + + EXPECT_LT((unsigned long)mmap_addresses.no_hint, 1UL << 47); + EXPECT_LT((unsigned long)mmap_addresses.on_37_addr, 1UL << 38); + EXPECT_LT((unsigned long)mmap_addresses.on_38_addr, 1UL << 38); + EXPECT_LT((unsigned long)mmap_addresses.on_46_addr, 1UL << 38); + EXPECT_LT((unsigned long)mmap_addresses.on_47_addr, 1UL << 47); + EXPECT_LT((unsigned long)mmap_addresses.on_55_addr, 1UL << 47); + EXPECT_LT((unsigned long)mmap_addresses.on_56_addr, 1UL << 56); +#endif +} + +TEST(zero_rlimit) +{ +// Only works on 64 bit +#if __riscv_xlen == 64 + struct addresses mmap_addresses; + struct rlimit rlim_new = { .rlim_cur = 0, .rlim_max = RLIM_INFINITY }; + + setrlimit(RLIMIT_STACK, &rlim_new); + + do_mmaps(&mmap_addresses); + + EXPECT_NE(mmap_addresses.no_hint, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_37_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_38_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_46_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_47_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_55_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_56_addr, MAP_FAILED); + + EXPECT_LT((unsigned long)mmap_addresses.no_hint, 1UL << 47); + EXPECT_LT((unsigned long)mmap_addresses.on_37_addr, 1UL << 38); + EXPECT_LT((unsigned long)mmap_addresses.on_38_addr, 1UL << 38); + EXPECT_LT((unsigned long)mmap_addresses.on_46_addr, 1UL << 38); + EXPECT_LT((unsigned long)mmap_addresses.on_47_addr, 1UL << 47); + EXPECT_LT((unsigned long)mmap_addresses.on_55_addr, 1UL << 47); + EXPECT_LT((unsigned long)mmap_addresses.on_56_addr, 1UL << 56); +#endif +} + +TEST(infinite_rlimit) +{ +// Only works on 64 bit +#if __riscv_xlen == 64 + struct addresses mmap_addresses; + struct rlimit rlim_new = { .rlim_cur = RLIM_INFINITY, + .rlim_max = RLIM_INFINITY }; + + setrlimit(RLIMIT_STACK, &rlim_new); + + do_mmaps(&mmap_addresses); + + EXPECT_NE(mmap_addresses.no_hint, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_37_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_38_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_46_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_47_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_55_addr, MAP_FAILED); + EXPECT_NE(mmap_addresses.on_56_addr, MAP_FAILED); + + EXPECT_LT((unsigned long)mmap_addresses.no_hint, 1UL << 47); + EXPECT_LT((unsigned long)mmap_addresses.on_37_addr, 1UL << 38); + EXPECT_LT((unsigned long)mmap_addresses.on_38_addr, 1UL << 38); + EXPECT_LT((unsigned long)mmap_addresses.on_46_addr, 1UL << 38); + EXPECT_LT((unsigned long)mmap_addresses.on_47_addr, 1UL << 47); + EXPECT_LT((unsigned long)mmap_addresses.on_55_addr, 1UL << 47); + EXPECT_LT((unsigned long)mmap_addresses.on_56_addr, 1UL << 56); +#endif +} + +TEST_HARNESS_MAIN From patchwork Fri Jul 14 16:54:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Charlie Jenkins X-Patchwork-Id: 13313860 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 2C672EB64DC for ; Fri, 14 Jul 2023 16:56:15 +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=p9DGfU2LAYi9xUmWGZBVnkyQNplSZ1iMF81G6Jng2Fs=; b=NeWNcknd82oLaO m0wcyHlyFooRXrvndLnjo5UTW7uj2sI0dzCKe6niLsRdrfIzkKFfUxxjqeLsbejkdmND3bVvkqy67 TIImLNVekg28d7KoXg6FzIAyYj66e/a65Msbk1CEC10zgvlg/mGqV/VObLx0Cr3cSFptp9iE0Fp3z qpwN6HTf4tGLPduzUIXJZkSRFp2PPxhBkisWB51vCIWaIqOb4XbO39lM8fKBbUW/7fHL+0BLsIGub uB7MVQSqBQMGaE5SLsXACLhftees/V3FF93ujgqC6omz9NMG4ch/b5hBVL7GG1S4KDVhd81y3y418 vaJ+DQf1ZthgRitZW8+Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qKM5Q-006hcF-27; Fri, 14 Jul 2023 16:56:08 +0000 Received: from mail-pf1-x435.google.com ([2607:f8b0:4864:20::435]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qKM5L-006hU6-1D for linux-riscv@lists.infradead.org; Fri, 14 Jul 2023 16:56:06 +0000 Received: by mail-pf1-x435.google.com with SMTP id d2e1a72fcca58-66c729f5618so2060113b3a.1 for ; Fri, 14 Jul 2023 09:56:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1689353759; x=1689958559; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=WogNqZmM5qIDEUwvyRv9RC9FRo2r68Wx4DIsyw3FtoM=; b=0OBaa8eGB7H0rgB6atdvkGk65g6hngFNmUyQKFx3pt0cyXW/YlErSR1NFqPJjQVIBn Qbx2cPxubOqOi6CSq5mhghxg0+jKeUjUth4gkGEcm1phj0JCTkUT4Z0lC3uJHMPft2S9 cPfIhhdmeOpgAr3dJxiUolv0aIchuoAsBArXrM1/wxA34E4mOly1ZMEShAAkToUUbVKM T+UDmYWmaiy+RMU7RefKaOVjxXWMIriJy9dkCKzFl17rP0lW4tlkFRkQ312UxNQYk2ZT R+0aW+ORT+YA+DbgWTkxGEBc255W3YFG1qbu5NQulHcux6fpsOtYFyHkWoDqKBUEUQsz f9gg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689353759; x=1689958559; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=WogNqZmM5qIDEUwvyRv9RC9FRo2r68Wx4DIsyw3FtoM=; b=SXdsOXlFfvrOoytWhO7FpuHuwz0HVGzXgMUCe3z7O3lQgpA+MQJQ6rqpuTRPafoPHN jySThnHReBvMwLCy0/+euqyuiznMIfL3r+0RxeqGrvIN6JcbEeksF/KvqdZ3feNu9n6C 4IGUAk3rUNOiJnKtgfOb7DExIC8FNNqaLfQLFjJ2m0OZ25YQhEo5BH1NG6F4xWleVRRE 0P/gASmwfzNovT6pNzsMp86YARlcwn4nA54Y8Ddwz/tP8ek0zdzdPJ/IUrUiLYE18/fs 8iCymGE5lIeY2+eC42I79zEiv4H9s9O+EQbAFAPOccXVfctYpKYFsip+ExKhGyi6CmAw kFVg== X-Gm-Message-State: ABy/qLYCORVBy0zAIGHTovG9BaSFnqRfyEOFgNLtVXx9DvC/pkEvhUrl PxURTL4Jrqd9whAGZQJT8rvbAlHu4oqbGeJLuKI= X-Google-Smtp-Source: APBJJlFI//JCJ/vZz+Q9PwxyNeL/qKz+QPWaKPFke/aicziyFeQBMzZv9VLqcfrN88UuwdEdg68umg== X-Received: by 2002:a05:6a20:639e:b0:133:ee16:5677 with SMTP id m30-20020a056a20639e00b00133ee165677mr1028643pzg.59.1689353759643; Fri, 14 Jul 2023 09:55:59 -0700 (PDT) Received: from charlie.ba.rivosinc.com ([66.220.2.162]) by smtp.gmail.com with ESMTPSA id s8-20020a170902b18800b001b694140d96sm8008081plr.170.2023.07.14.09.55.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Jul 2023 09:55:59 -0700 (PDT) From: Charlie Jenkins To: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: charlie@rivosinc.com, conor@kernel.org, paul.walmsley@sifive.com, palmer@rivosinc.com, aou@eecs.berkeley.edu, anup@brainfault.org, konstantin@linuxfoundation.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, mick@ics.forth.gr, jrtc27@jrtc27.com, rdunlap@infradead.org, alexghiti@rivosinc.com Subject: [PATCH v6 3/4] RISC-V: mm: Update pgtable comment documentation Date: Fri, 14 Jul 2023 09:54:51 -0700 Message-ID: <20230714165508.94561-4-charlie@rivosinc.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230714165508.94561-1-charlie@rivosinc.com> References: <20230714165508.94561-1-charlie@rivosinc.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230714_095603_429498_E78F55B5 X-CRM114-Status: UNSURE ( 9.41 ) X-CRM114-Notice: Please train this message. X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org sv57 is supported in the kernel so pgtable.h should reflect that. Signed-off-by: Charlie Jenkins Reviewed-by: Alexandre Ghiti --- arch/riscv/include/asm/pgtable.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index e13f5872bfe9..28660bab754c 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -840,14 +840,16 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte) * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32. * Note that PGDIR_SIZE must evenly divide TASK_SIZE. * Task size is: - * - 0x9fc00000 (~2.5GB) for RV32. - * - 0x4000000000 ( 256GB) for RV64 using SV39 mmu - * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu + * - 0x9fc00000 (~2.5GB) for RV32. + * - 0x4000000000 ( 256GB) for RV64 using SV39 mmu + * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu + * - 0x100000000000000 ( 64PB) for RV64 using SV57 mmu * * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V * Instruction Set Manual Volume II: Privileged Architecture" states that * "load and store effective addresses, which are 64bits, must have bits * 63–48 all equal to bit 47, or else a page-fault exception will occur." + * Similarly for SV57, bits 63–57 must be equal to bit 56. */ #ifdef CONFIG_64BIT #define TASK_SIZE_64 (PGDIR_SIZE * PTRS_PER_PGD / 2) From patchwork Fri Jul 14 16:54:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Charlie Jenkins X-Patchwork-Id: 13313858 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 C2200C0015E for ; Fri, 14 Jul 2023 16:56:12 +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=V92l50CiJ1sCsWj2ocpiZzebp5KggDSlkWw9gI22KWw=; b=UuHtCOa0eB4oGu cVHHcRsFi01LQqvP6Q7EP16vzkfcu6BP1RuZCbO2X18Si2CHCSVm/FlLvKKaOBw8WNNa4kFkTPWz7 gnqzamIYXnOx673irEThTmF03oXfVVoWFP3QJjrCr+cPlJDWub2uSSp7zLdzF31VPaBOuPM2+b9bD BzClaiXlIH9JDAeVW/NVNomiia69vA1rtjwX2Lofv4hBEGPbsSJpEG5Ui+u2W7cXiB1Y+8vBfVsGY qxuqqc/mjLk/bTHbVBKO51X7jUEXR736sr6c4sFj88FTFNWdKmgcfWWgJeNpZYgZFpjBIxC8PHjYJ 672BcSsT1xCse0ayWSGg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qKM5R-006hcZ-0i; Fri, 14 Jul 2023 16:56:09 +0000 Received: from mail-pl1-x629.google.com ([2607:f8b0:4864:20::629]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qKM5L-006hVn-1U for linux-riscv@lists.infradead.org; Fri, 14 Jul 2023 16:56:06 +0000 Received: by mail-pl1-x629.google.com with SMTP id d9443c01a7336-1b9ecf0cb4cso13055885ad.2 for ; Fri, 14 Jul 2023 09:56:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1689353761; x=1689958561; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=iY0BqE22+vH8ihdQ5F+U3lQTo4OY0Ve5Zo6wbRWfHfc=; b=ECP+dufnQHsYRxuqgPOTnUSVvIo4ePBLAYzcr/uPu+86xHXRbq559fnQxM4loYgYii 9q/1Ih5sS/4Nz4IV5XKxNs5M7eNK2wNCyxQPv1SoVXWcMmwbEpzI74Jdn1u5Cczfadul jSHTTTzLM34mcqiVS7oXLHnW//LVLHHdygX3s6M81zVFp+Lmjk+KCS/Jt+2NFtsSEwsS hM2QAfrxJ4G7EMIqqaMGTDm7wAokuRc+ct0d85q54+SDh5Xc1EJl+Md33rZrNOHTixiq BSKIqdZJu/lQ2SebCzY5jdSZwDdpY3w9ELYszKlZ96Lgs1OHBPPpkiA+q8wz6OTq9PHQ LbBw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689353761; x=1689958561; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=iY0BqE22+vH8ihdQ5F+U3lQTo4OY0Ve5Zo6wbRWfHfc=; b=CZM2Kxm0EHU4/GdO0+QnmyPlYfmYpgBkx+jHhTlEYMGTIIq7HWlRUBUKL+Ir7+kEOA qTHl7AQD6Z4zbMWOwsucZ5UJgPonxP5k5quxxtNepPFbe6V9FkBZt7Nd1UCUTfDbA5CN dg+EjFmug+1HdoeWsdc4+hSsr705yIDfQp+g+64VB2FZdty5AO5T6ZZnjznpZVSz8wU/ XqkWF3yZ/BbNJtR1AYOphIU9hozJ9GC1roI9iadDirdyqLknd/rTOu933iVPnVrYgg3D D1Z8GtyVayklm21uzYDo0MCI+VuWkD4paKMlrs6IliGwm7lWU036c1girCZr6OOm9zx0 kL1A== X-Gm-Message-State: ABy/qLY2FgYunl35DVhmMs4c6NY5Q8UFtsVlhbXgqQcfDXs8DvEJ0rxf 9SrU2hq/7u+HXggOR6xnN08LZV+yrMtksyZMe3I= X-Google-Smtp-Source: APBJJlFsvoNdVZTC5wGAHNOb7OEsPFjJFgSI3IvikXJ3ahp3VMzgfUgYU2kfHESUML2FBAHGPHaiUA== X-Received: by 2002:a17:903:1248:b0:1b3:d11c:23ca with SMTP id u8-20020a170903124800b001b3d11c23camr4729934plh.8.1689353761143; Fri, 14 Jul 2023 09:56:01 -0700 (PDT) Received: from charlie.ba.rivosinc.com ([66.220.2.162]) by smtp.gmail.com with ESMTPSA id s8-20020a170902b18800b001b694140d96sm8008081plr.170.2023.07.14.09.55.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 14 Jul 2023 09:56:00 -0700 (PDT) From: Charlie Jenkins To: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Cc: charlie@rivosinc.com, conor@kernel.org, paul.walmsley@sifive.com, palmer@rivosinc.com, aou@eecs.berkeley.edu, anup@brainfault.org, konstantin@linuxfoundation.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, mick@ics.forth.gr, jrtc27@jrtc27.com, rdunlap@infradead.org, alexghiti@rivosinc.com Subject: [PATCH v6 4/4] RISC-V: mm: Document mmap changes Date: Fri, 14 Jul 2023 09:54:52 -0700 Message-ID: <20230714165508.94561-5-charlie@rivosinc.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230714165508.94561-1-charlie@rivosinc.com> References: <20230714165508.94561-1-charlie@rivosinc.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230714_095603_527598_CE3128EB X-CRM114-Status: GOOD ( 11.75 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org The behavior of mmap is modified with this patch series, so explain the changes to the mmap hint address behavior. Signed-off-by: Charlie Jenkins --- Documentation/riscv/vm-layout.rst | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst index 5462c84f4723..892412b91300 100644 --- a/Documentation/riscv/vm-layout.rst +++ b/Documentation/riscv/vm-layout.rst @@ -133,3 +133,25 @@ RISC-V Linux Kernel SV57 ffffffff00000000 | -4 GB | ffffffff7fffffff | 2 GB | modules, BPF ffffffff80000000 | -2 GB | ffffffffffffffff | 2 GB | kernel __________________|____________|__________________|_________|____________________________________________________________ + + +Userspace VAs +-------------------- +To maintain compatibility with software that relies on the VA space with a +maximum of 48 bits the kernel will, by default, return virtual addresses to +userspace from a 48-bit range (sv48). This default behavior is achieved by +passing 0 into the hint address parameter of mmap. On CPUs with an address space +smaller than sv48, the CPU maximum supported address space will be the default. + +Software can "opt-in" to receiving VAs from another VA space by providing +a hint address to mmap. A call to mmap is guaranteed to return an address +that will not override the unset left-aligned bits in the hint address, +unless there is no space left in the address space. If there is no space +available in the requested address space, an address in the next smallest +available address space will be returned. + +For example, in order to obtain 48-bit VA space, a hint address greater than +:code:`1 << 38` must be provided. Note that this is 38 due to sv39 userspace +ending at :code:`1 << 38` and the addresses beyond this are reserved for the +kernel. Similarly, to obtain 57-bit VA space addresses, a hint address greater +than or equal to :code:`1 << 47` must be provided.