From patchwork Tue Jun 27 22:21:52 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Charlie Jenkins X-Patchwork-Id: 697049 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 98C39C001B3 for ; Tue, 27 Jun 2023 22:23:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229923AbjF0WX3 (ORCPT ); Tue, 27 Jun 2023 18:23:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229599AbjF0WX2 (ORCPT ); Tue, 27 Jun 2023 18:23:28 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 422F9210C for ; Tue, 27 Jun 2023 15:23:26 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id d9443c01a7336-1b7f92b764dso17077505ad.2 for ; Tue, 27 Jun 2023 15:23:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1687904606; x=1690496606; 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=sH+Wgq7qee9mtA5bUr48f+V2rObrYAubOQ/hBwHBBAk=; b=y41+mA0wh04l+sQWluLgmd1jSqcTr/HA7DaxiS6c9aczxK3HYLCmNJESgzCbW6OdBN FwvAmkMiyUkScxfJUW8MsBP3FTL0tCbLbOlNnyCWXPY/bgTaVY7H9RcutAYTxaBIzJcq P+qJdFgcm/GhafVqu8F8J3HGYODyl1F8zt87AJLcdNFKQ3yA3riDJAcEV1ohdF+6VILt p8XJ+aV/MD2XLYSKblvGwJxd7LGpCz4AMyCHHNQZz8nYURz29NDYo0gLP81u1dckJVQO MWiNpGOrZ657T3kF/bQ6j34XI55Zi+Gg3ZOgNECcYaHlABP0EN4+5SgIoXiZtXyVEqKs jH3g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687904606; x=1690496606; 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=sH+Wgq7qee9mtA5bUr48f+V2rObrYAubOQ/hBwHBBAk=; b=e4Y8HwqRhgfH9xvpd9wKHjbLAl07gzEEHrNXC9RH+CaLYfJxdVlOYXEyP4fyVivTVK fpEkAmkscYE4XJEn0PTk9uFUlacvdKlmZftV8GoFmdEKwCsxKGHEiXewSZducl0VQSda Sx9T/ttyWvvpLc6T4VQZP9KHJv7XbMQhG3a9OnOZhMuobDA7RF4Ygy9dJbwA5va366rA hdcU2VpAaxZCjCB9G8+HJMm0BLNDctvTcmz6aQw65WGoM4RSYU3lkZ/Jznw5ABvpnnnT 27sJgdr/0ZY+wSPCCGODydE0WD5a+prYqz4zy8Ti/kbwzG2kXYTeSXatVTqAxVImQlm/ JwSw== X-Gm-Message-State: AC+VfDzehxpnaHyzVi1+b526BIkMZ+pPzYo5Scvgdx4HWIKE4T8iZfvr fHa+4HbZq5OdT56Rl8xoeAvgAg== X-Google-Smtp-Source: ACHHUZ6MMEoHIIDVfAf9FbmmHVV5VLT+dty6U2enPQJhMVqDP1Ibu705NkrmDGegdnI72fct0/qTfA== X-Received: by 2002:a17:903:2307:b0:1b8:1335:b799 with SMTP id d7-20020a170903230700b001b81335b799mr5112914plh.51.1687904605695; Tue, 27 Jun 2023 15:23:25 -0700 (PDT) Received: from ghost.hq.rivosinc.com ([50.221.140.188]) by smtp.gmail.com with ESMTPSA id 4-20020a170902c24400b001ac94b33ab1sm5108271plg.304.2023.06.27.15.23.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Jun 2023 15:23:25 -0700 (PDT) From: Charlie Jenkins To: alexghiti@rivosinc.com Cc: charlie@rivosinc.com, atishp@rivosinc.com, conor@kernel.org, paul.walmsley@sifive.com, palmer@rivosinc.com, aou@eecs.berkeley.edu, bjorn@rivosinc.com, anup@brainfault.org, evan@rivosinc.com, linux-riscv@lists.infradead.org, konstantin@linuxfoundation.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 2/2] RISC-V: mm: Update documentation and include test Date: Tue, 27 Jun 2023 15:21:52 -0700 Message-Id: <20230627222152.177716-3-charlie@rivosinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230627222152.177716-1-charlie@rivosinc.com> References: <20230627222152.177716-1-charlie@rivosinc.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Add documentation explaining the behavior of mmap. Include a simple test that ensures that mmap returns an address less than the hint address while there are still addresses available. Signed-off-by: Charlie Jenkins --- Documentation/riscv/vm-layout.rst | 20 ++++++++ arch/riscv/include/asm/pgtable.h | 8 +-- tools/testing/selftests/riscv/Makefile | 2 +- tools/testing/selftests/riscv/mm/Makefile | 22 +++++++++ .../selftests/riscv/mm/testcases/mmap.c | 49 +++++++++++++++++++ 5 files changed, 97 insertions(+), 4 deletions(-) create mode 100644 tools/testing/selftests/riscv/mm/Makefile create mode 100644 tools/testing/selftests/riscv/mm/testcases/mmap.c diff --git a/Documentation/riscv/vm-layout.rst b/Documentation/riscv/vm-layout.rst index 5462c84f4723..365a481be90b 100644 --- a/Documentation/riscv/vm-layout.rst +++ b/Documentation/riscv/vm-layout.rst @@ -133,3 +133,23 @@ 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 39-bits, the kernel will, by default, return virtual +return virtual addresses to userspace from a 39-bit range. + +Software can "opt-in" to receiving VAs from other 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` with the addresses beyond this and up to :code:`1 << 39` +being 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. diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index e83912e97870..93e7233d5d2a 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -841,14 +841,16 @@ 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) diff --git a/tools/testing/selftests/riscv/Makefile b/tools/testing/selftests/riscv/Makefile index 32a72902d045..0fee58f990ae 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 +RISCV_SUBTARGETS ?= hwprobe mm else RISCV_SUBTARGETS := endif diff --git a/tools/testing/selftests/riscv/mm/Makefile b/tools/testing/selftests/riscv/mm/Makefile new file mode 100644 index 000000000000..4aadf04401db --- /dev/null +++ b/tools/testing/selftests/riscv/mm/Makefile @@ -0,0 +1,22 @@ +# SPDX-License-Identifier: GPL-2.0 +# Copyright (C) 2019 ARM Limited +# 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)/ \ No newline at end of file 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..aa37a623b93f --- /dev/null +++ b/tools/testing/selftests/riscv/mm/testcases/mmap.c @@ -0,0 +1,49 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include "../../kselftest_harness.h" + +TEST(sv57_test) +{ + // Only works on 64 bit + #if __riscv_xlen == 64 + // 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; + + int *no_hint = mmap(NULL, 5*sizeof(int), prot, flags, 0, 0); + int *on_37_addr = mmap(on_37_bits, 5*sizeof(int), prot, flags, 0, 0); + int *on_38_addr = mmap(on_38_bits, 5*sizeof(int), prot, flags, 0, 0); + int *on_46_addr = mmap(on_46_bits, 5*sizeof(int), prot, flags, 0, 0); + int *on_47_addr = mmap(on_47_bits, 5*sizeof(int), prot, flags, 0, 0); + int *on_55_addr = mmap(on_55_bits, 5*sizeof(int), prot, flags, 0, 0); + int *on_56_addr = mmap(on_56_bits, 5*sizeof(int), prot, flags, 0, 0); + + EXPECT_NE(no_hint, MAP_FAILED); + EXPECT_NE(on_37_addr, MAP_FAILED); + EXPECT_NE(on_38_addr, MAP_FAILED); + EXPECT_NE(on_46_addr, MAP_FAILED); + EXPECT_NE(on_47_addr, MAP_FAILED); + EXPECT_NE(on_55_addr, MAP_FAILED); + EXPECT_NE(on_56_addr, MAP_FAILED); + + EXPECT_LT((unsigned long) no_hint, 1UL << 38); + EXPECT_LT((unsigned long) on_37_addr, 1UL << 38); + EXPECT_LT((unsigned long) on_38_addr, 1UL << 38); + EXPECT_LT((unsigned long) on_46_addr, 1UL << 38); + EXPECT_LT((unsigned long) on_47_addr, 1UL << 47); + EXPECT_LT((unsigned long) on_55_addr, 1UL << 47); + EXPECT_LT((unsigned long) on_56_addr, 1UL << 57); + #else + #endif +} + +TEST_HARNESS_MAIN