From patchwork Mon Jun 26 18:36:04 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Charlie Jenkins X-Patchwork-Id: 13293342 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 551DDEB64D7 for ; Mon, 26 Jun 2023 18:42:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B8F878D0002; Mon, 26 Jun 2023 14:42:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B18738D0001; Mon, 26 Jun 2023 14:42:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 96B378D0002; Mon, 26 Jun 2023 14:42:20 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 847BC8D0001 for ; Mon, 26 Jun 2023 14:42:20 -0400 (EDT) Received: from smtpin06.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 5D20FC080E for ; Mon, 26 Jun 2023 18:42:20 +0000 (UTC) X-FDA: 80945769240.06.F504989 Received: from mail-pl1-f193.google.com (mail-pl1-f193.google.com [209.85.214.193]) by imf25.hostedemail.com (Postfix) with ESMTP id 42D7FA001E for ; Mon, 26 Jun 2023 18:42:17 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=rivosinc-com.20221208.gappssmtp.com header.s=20221208 header.b=5jOcJbYg; spf=pass (imf25.hostedemail.com: domain of charlie@rivosinc.com designates 209.85.214.193 as permitted sender) smtp.mailfrom=charlie@rivosinc.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1687804938; a=rsa-sha256; cv=none; b=jKPPRAS2Q/poAuEsquQ44sqgquqQAp9r5PtX6T8QeMQKT8pzhgUZ0s15Z3EJRidTOZtSHx 5pOsz+UWdU/NQZjB/cCcdItJLfovXb+SrWkRXWqLKUL8uFcNiymnulWe9uMcY6QZ2F4E/1 QVr02IGCtJM3fx2PMAmmUq691yvK3uo= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=rivosinc-com.20221208.gappssmtp.com header.s=20221208 header.b=5jOcJbYg; spf=pass (imf25.hostedemail.com: domain of charlie@rivosinc.com designates 209.85.214.193 as permitted sender) smtp.mailfrom=charlie@rivosinc.com; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1687804938; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=sH+Wgq7qee9mtA5bUr48f+V2rObrYAubOQ/hBwHBBAk=; b=ndD3brU5GtXrG5cc/hoaLrN2hCgj3HOzQHSUnqNl7Dfo9LDgYKGBHYibo2i1SYjAFhteiN yA4jsApWz2HvZfowwSkfzblIs6bdN5nqtPybUirx2jgKrLx36DKkPd1XjoknIrZ4+KK0LY lTlrmNDzkKiYaSzGhyMLGQT/iEtFRnY= Received: by mail-pl1-f193.google.com with SMTP id d9443c01a7336-1b7fb1a82c4so8955155ad.1 for ; Mon, 26 Jun 2023 11:42:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20221208.gappssmtp.com; s=20221208; t=1687804937; x=1690396937; 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=5jOcJbYgURyb3J6wys4kHRocknTCyFf9DmYKXPI6WWwFeH+IzDzf8V7qBxgAk6QiFe ZICQr2wByw+QIh2YHTfcNCq9n0qjNOw4Ux1PdpIGnxS0bNO3kHmjjtSB1dN2tW8zrD5m MfqhEyFNRJ5XVCFouju9OuMkzzH9kI0/ofGhS8pMKE/DJE4cmqIrUQFr+C66H6LQg0ll kdWhcs0rTAwl1+SQiKOCLt5XPDSIMd3AyVGP9SQBZRTSOLy5fRGduX0thzH4ORM8A8yV W0nWciMAD0ErUCdeiyqpQ+3+G2wl/KtPYyBuHHtI8gdcF7FOmPHxAvvYu7IUinmCM7Ai IILA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687804937; x=1690396937; 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=bZOUAyxdz9bz/xVWiUnWiAuuHeqtyEKu/pnyMTFj2Ph7WzE42qtDGABx1K9+32+AYN k6MWdzhaFqI2C9Ut9A1fWQG4NNTlKfoJU5jA3BjKfPrNYI0F6oXHseKhZRxqFPLxzA1K pC8SxxKfHFApWm/XtENQSIE5I6hzlk1zzHa6qQWkFO8H5gXt1fVXOPHvY19ifKbxX6NT JhulSaR+kFLwcE9LE6QhKQ/up9LvwdDd9ciNnavtHLt/7MPqALthIEU2Tc/LpEw7uiZb K8jpAlHvxUqDbOUPjyrRn/vN8l5bEQILgTG8UmUQPnNyBHJ4RUbRbGvQRsfIF/UAkER7 NOlw== X-Gm-Message-State: AC+VfDzV86De9Os69a6KaR8INAluylcDNgsY2MnhNHIZuLhMBaW103F1 cRMRWlgzHMbVW1XBGpsWW1MBtQ== X-Google-Smtp-Source: ACHHUZ7GAK2YSHgB1Pfl7VnnRZIXnXSTX8LZ1n4BLxAfd60w8XE6TD9SeBhk2ADjGleoRlERF2HeNw== X-Received: by 2002:a17:903:1250:b0:1b5:3c7f:1b3b with SMTP id u16-20020a170903125000b001b53c7f1b3bmr6938892plh.35.1687804936989; Mon, 26 Jun 2023 11:42:16 -0700 (PDT) Received: from ghost.hq.rivosinc.com ([50.221.140.188]) by smtp.gmail.com with ESMTPSA id y6-20020a1709029b8600b001b682336f66sm4499842plp.55.2023.06.26.11.42.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jun 2023 11:42:16 -0700 (PDT) From: Charlie Jenkins To: charlie@rivosinc.com Cc: Jonathan Corbet , Paul Walmsley , Palmer Dabbelt , Albert Ou , Eric Biederman , Kees Cook , Shuah Khan , Alexandre Ghiti , Conor Dooley , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , Greentime Hu , Zong Li , Andrew Morton , Guo Ren , Sergey Matyukevich , David Hildenbrand , Qinglin Pan , Anshuman Khandual , Catalin Marinas , Sunil V L , Stafford Horne , Anup Patel , Kefeng Wang , Evan Green , Guillaume Tucker , Mark Brown , linux-doc@vger.kernel.org (open list:DOCUMENTATION), linux-riscv@lists.infradead.org (open list:RISC-V ARCHITECTURE), linux-kernel@vger.kernel.org (open list), linux-mm@kvack.org (open list:EXEC & BINFMT API), linux-kselftest@vger.kernel.org (open list:KERNEL SELFTEST FRAMEWORK) Subject: [PATCH 2/2] RISC-V: mm: Update documentation and include test Date: Mon, 26 Jun 2023 11:36:04 -0700 Message-Id: <20230626183611.40479-3-charlie@rivosinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230626183611.40479-1-charlie@rivosinc.com> References: <20230626183611.40479-1-charlie@rivosinc.com> MIME-Version: 1.0 X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 42D7FA001E X-Stat-Signature: p7byf73f6ecttqjjaq7jdnkndbj5tkwg X-Rspam-User: X-HE-Tag: 1687804937-708173 X-HE-Meta: U2FsdGVkX1+KDlGU9xKFdiiWzW4h5Q/2ho5xt7/LhwoQgqYSLzAqJTDABaVrbMwJ5Qjrg8g0Lbgf5uyabKydkJ5bRlu8GbMVMoYqYGSL/R0gRX50YFuJsTJSXZIJAk1NNRw8r4EP/o46qFi/jT5MiIYEDr+x/v1ZbHZjjrzvbdpEaF+faO81lhguEprK4dFbaVmySoQEcVUD3027MYuIb5bbr/u89G+R6kIuEHTuqSxYguaLGEW3IXgChj+eEwepD0k2mouFYQioHeVcmJyJzfVSnAtwVnRgdCcQMkd78LzJGScUW1KP1vi+uxIxeQ1ihxzCWl+KU6OBv7t8HdukU1TPSHIYGVmUdMrS/vLDhjv70IwfLmBhapqqUxBxaoLD0dw343GIOT7TsfB0hkJgK7E6Sf8pj8v0bF/VuSBy8VYmBO4sqCXSauoPP3ukmMT3FY9IcAQPuuuuT0s4w7As1zjJfyj7ISaPJUGmDPNCvlKegrH/ZScavkPJ2Y0H0QA5wZfbgWNHfVDpVyoe7NvAbwYYBpXt1NOzU9oUR2y7Y6Q6EfiV7qdfF5RnJ81+oweW7M/K0ve102BJTUGlCnM07CajsHqMrABuQ71ZF3gOgAShFeGFKh9w5O0ggKHbAhAZn6SJfskOPStVCpiiNaq0Ro/UEIhUEtYFGu2S/Occ2imKo9LadaNnfYV1KT1OQ0wxUBVtni1mRbafUlWDi3Nf7NRZUGnkIjjWjh7OZ1BZ5WokwgakMk3Qh2RdAbCpMjmi37yjzPcJeu/9V73X9PwZMM7JeSLHedaxb5mhd96ohZ044gE6YRLYHHMPBQ3xrB4waJQhcmOeYuCat3v9+eNG2kO1A+U4aV2CXFAL4VrbVu2mrvnFP/cfjM7wPyF2gBkFWaqsFO4Nzx0JaByhQDNW6lXd3fG2I4W72i5nrne3lExu+W1Kt1yMTiE0za+8Q1ygDqv6brXw/F2phjAPLel DuJvhh67 6Hvuy4ID7oSA85ynSQB53+dEm33Nc9qFAk51trwyKgupRE5tkOUiYA18vnO6cFU8AyTEtsRplfLcfXXA4Kxh+RUuFwKlzadKRbNuv64UQX443k/+nwobkE2wvqUVmVnlSYOBN8RwnQpT1lIzQKmQqYFb4MrHEdhKnPctuCmWhO9oBNUO5Ao+Ih9hpjvgzZkQqqlRp+irOoMpnr+06dzCCcIX2feCQqMmPaK+2ft38kfZJB6lWuvljYSNJfOKDaEsKBSUfxARNsZPPTG3VaFeVGUH/7hZK/lYsVE+w1pnLciHDMpEfpnCrihRDPZaY0Oug2AK6STs5P1nNokKSosvwfNtVc7n3o9RNQlFIbp0MPvCXaurd3UVPYprRTEfdV5hZyATssgMtX32Tfqerz0VRYO46zVaO/eP3O4W9kgEpnEK+yxVO5uJtNykpoVuDphaTjpyP+rm4s2sGU/k= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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