[v1,2/6] RISC-V: Move the hwprobe syscall to its own file

Message ID	20231011135610.122850-10-ajones@ventanamicro.com (mailing list archive)
State	Superseded
Headers	show Return-Path: <linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org> From: Andrew Jones <ajones@ventanamicro.com> To: linux-riscv@lists.infradead.org Cc: paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, evan@rivosinc.com, conor.dooley@microchip.com, apatel@ventanamicro.com Subject: [PATCH v1 2/6] RISC-V: Move the hwprobe syscall to its own file Date: Wed, 11 Oct 2023 15:56:13 +0200 Message-ID: <20231011135610.122850-10-ajones@ventanamicro.com> In-Reply-To: <20231011135610.122850-8-ajones@ventanamicro.com> References: <20231011135610.122850-8-ajones@ventanamicro.com> MIME-Version: 1.0 Precedence: list Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" <linux-riscv-bounces@lists.infradead.org> Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org
Series	RISC-V: hwprobe: Introduce which-cpus \| expand [v1,0/6] RISC-V: hwprobe: Introduce which-cpus [v1,1/6] RISC-V: hwprobe: Clarify cpus size parameter [v1,2/6] RISC-V: Move the hwprobe syscall to its own file [v1,3/6] RISC-V: hwprobe: Introduce which-cpus flag [v1,4/6] RISC-V: selftests: Statically link hwprobe test [v1,5/6] RISC-V: selftests: Convert hwprobe test to kselftest API [v1,6/6] RISC-V: selftests: Add which-cpus hwprobe test

Context	Check	Description
conchuod/vmtest-fixes-PR	fail	merge-conflict

diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index 95cf25d48405..db7a43211b30 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -50,6 +50,7 @@ obj-y += setup.o obj-y += signal.o obj-y += syscall_table.o obj-y += sys_riscv.o +obj-y += sys_hwprobe.o obj-y += time.o obj-y += traps.o obj-y += riscv_ksyms.o diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c new file mode 100644 index 000000000000..69ad5f793374 --- /dev/null +++ b/arch/riscv/kernel/sys_hwprobe.c @@ -0,0 +1,276 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * The hwprobe interface, for allowing userspace to probe to see which features + * are supported by the hardware. See Documentation/riscv/hwprobe.rst for more + * details. + * + * Copyright (C) 2012 Regents of the University of California + * Copyright (C) 2014 Darius Rad <darius@bluespec.com> + * Copyright (C) 2017 SiFive + */ + +#include <linux/syscalls.h> +#include <asm/cacheflush.h> +#include <asm/cpufeature.h> +#include <asm/hwprobe.h> +#include <asm/sbi.h> +#include <asm/switch_to.h> +#include <asm/uaccess.h> +#include <asm/unistd.h> +#include <asm/vector.h> +#include <vdso/vsyscall.h> + + +static void hwprobe_arch_id(struct riscv_hwprobe *pair, + const struct cpumask *cpus) +{ + u64 id = -1ULL; + bool first = true; + int cpu; + + for_each_cpu(cpu, cpus) { + u64 cpu_id; + + switch (pair->key) { + case RISCV_HWPROBE_KEY_MVENDORID: + cpu_id = riscv_cached_mvendorid(cpu); + break; + case RISCV_HWPROBE_KEY_MIMPID: + cpu_id = riscv_cached_mimpid(cpu); + break; + case RISCV_HWPROBE_KEY_MARCHID: + cpu_id = riscv_cached_marchid(cpu); + break; + } + + if (first) { + id = cpu_id; + first = false; + } + + /* + * If there's a mismatch for the given set, return -1 in the + * value. + */ + if (id != cpu_id) { + id = -1ULL; + break; + } + } + + pair->value = id; +} + +static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, + const struct cpumask *cpus) +{ + int cpu; + u64 missing = 0; + + pair->value = 0; + if (has_fpu()) + pair->value |= RISCV_HWPROBE_IMA_FD; + + if (riscv_isa_extension_available(NULL, c)) + pair->value |= RISCV_HWPROBE_IMA_C; + + if (has_vector()) + pair->value |= RISCV_HWPROBE_IMA_V; + + /* + * Loop through and record extensions that 1) anyone has, and 2) anyone + * doesn't have. + */ + for_each_cpu(cpu, cpus) { + struct riscv_isainfo *isainfo = &hart_isa[cpu]; + + if (riscv_isa_extension_available(isainfo->isa, ZBA)) + pair->value |= RISCV_HWPROBE_EXT_ZBA; + else + missing |= RISCV_HWPROBE_EXT_ZBA; + + if (riscv_isa_extension_available(isainfo->isa, ZBB)) + pair->value |= RISCV_HWPROBE_EXT_ZBB; + else + missing |= RISCV_HWPROBE_EXT_ZBB; + + if (riscv_isa_extension_available(isainfo->isa, ZBS)) + pair->value |= RISCV_HWPROBE_EXT_ZBS; + else + missing |= RISCV_HWPROBE_EXT_ZBS; + } + + /* Now turn off reporting features if any CPU is missing it. */ + pair->value &= ~missing; +} + +static u64 hwprobe_misaligned(const struct cpumask *cpus) +{ + int cpu; + u64 perf = -1ULL; + + for_each_cpu(cpu, cpus) { + int this_perf = per_cpu(misaligned_access_speed, cpu); + + if (perf == -1ULL) + perf = this_perf; + + if (perf != this_perf) { + perf = RISCV_HWPROBE_MISALIGNED_UNKNOWN; + break; + } + } + + if (perf == -1ULL) + return RISCV_HWPROBE_MISALIGNED_UNKNOWN; + + return perf; +} + +static void hwprobe_one_pair(struct riscv_hwprobe *pair, + const struct cpumask *cpus) +{ + switch (pair->key) { + case RISCV_HWPROBE_KEY_MVENDORID: + case RISCV_HWPROBE_KEY_MARCHID: + case RISCV_HWPROBE_KEY_MIMPID: + hwprobe_arch_id(pair, cpus); + break; + /* + * The kernel already assumes that the base single-letter ISA + * extensions are supported on all harts, and only supports the + * IMA base, so just cheat a bit here and tell that to + * userspace. + */ + case RISCV_HWPROBE_KEY_BASE_BEHAVIOR: + pair->value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA; + break; + + case RISCV_HWPROBE_KEY_IMA_EXT_0: + hwprobe_isa_ext0(pair, cpus); + break; + + case RISCV_HWPROBE_KEY_CPUPERF_0: + pair->value = hwprobe_misaligned(cpus); + break; + + /* + * For forward compatibility, unknown keys don't fail the whole + * call, but get their element key set to -1 and value set to 0 + * indicating they're unrecognized. + */ + default: + pair->key = -1; + pair->value = 0; + break; + } +} + +static int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs, + size_t pair_count, size_t cpusetsize, + unsigned long __user *cpus_user, + unsigned int flags) +{ + size_t out; + int ret; + cpumask_t cpus; + + /* Check the reserved flags. */ + if (flags != 0) + return -EINVAL; + + /* + * The interface supports taking in a CPU mask, and returns values that + * are consistent across that mask. Allow userspace to specify NULL and + * 0 as a shortcut to all online CPUs. + */ + cpumask_clear(&cpus); + if (!cpusetsize && !cpus_user) { + cpumask_copy(&cpus, cpu_online_mask); + } else { + if (cpusetsize > cpumask_size()) + cpusetsize = cpumask_size(); + + ret = copy_from_user(&cpus, cpus_user, cpusetsize); + if (ret) + return -EFAULT; + + /* + * Userspace must provide at least one online CPU, without that + * there's no way to define what is supported. + */ + cpumask_and(&cpus, &cpus, cpu_online_mask); + if (cpumask_empty(&cpus)) + return -EINVAL; + } + + for (out = 0; out < pair_count; out++, pairs++) { + struct riscv_hwprobe pair; + + if (get_user(pair.key, &pairs->key)) + return -EFAULT; + + pair.value = 0; + hwprobe_one_pair(&pair, &cpus); + ret = put_user(pair.key, &pairs->key); + if (ret == 0) + ret = put_user(pair.value, &pairs->value); + + if (ret) + return -EFAULT; + } + + return 0; +} + +#ifdef CONFIG_MMU + +static int __init init_hwprobe_vdso_data(void) +{ + struct vdso_data *vd = __arch_get_k_vdso_data(); + struct arch_vdso_data *avd = &vd->arch_data; + u64 id_bitsmash = 0; + struct riscv_hwprobe pair; + int key; + + /* + * Initialize vDSO data with the answers for the "all CPUs" case, to + * save a syscall in the common case. + */ + for (key = 0; key <= RISCV_HWPROBE_MAX_KEY; key++) { + pair.key = key; + hwprobe_one_pair(&pair, cpu_online_mask); + + WARN_ON_ONCE(pair.key < 0); + + avd->all_cpu_hwprobe_values[key] = pair.value; + /* + * Smash together the vendor, arch, and impl IDs to see if + * they're all 0 or any negative. + */ + if (key <= RISCV_HWPROBE_KEY_MIMPID) + id_bitsmash |= pair.value; + } + + /* + * If the arch, vendor, and implementation ID are all the same across + * all harts, then assume all CPUs are the same, and allow the vDSO to + * answer queries for arbitrary masks. However if all values are 0 (not + * populated) or any value returns -1 (varies across CPUs), then the + * vDSO should defer to the kernel for exotic cpu masks. + */ + avd->homogeneous_cpus = id_bitsmash != 0 && id_bitsmash != -1; + return 0; +} + +arch_initcall_sync(init_hwprobe_vdso_data); + +#endif /* CONFIG_MMU */ + +SYSCALL_DEFINE5(riscv_hwprobe, struct riscv_hwprobe __user *, pairs, + size_t, pair_count, size_t, cpusetsize, unsigned long __user *, + cpus, unsigned int, flags) +{ + return do_riscv_hwprobe(pairs, pair_count, cpusetsize, + cpus, flags); +} diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index ed3545eb1b2b..f1c1416a9f1e 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -7,15 +7,7 @@ #include <linux/syscalls.h> #include <asm/cacheflush.h> -#include <asm/cpufeature.h> -#include <asm/hwprobe.h> -#include <asm/sbi.h> -#include <asm/vector.h> -#include <asm/switch_to.h> -#include <asm/uaccess.h> -#include <asm/unistd.h> #include <asm-generic/mman-common.h> -#include <vdso/vsyscall.h> static long riscv_sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, @@ -77,265 +69,6 @@ SYSCALL_DEFINE3(riscv_flush_icache, uintptr_t, start, uintptr_t, end, return 0; } -/* - * The hwprobe interface, for allowing userspace to probe to see which features - * are supported by the hardware. See Documentation/riscv/hwprobe.rst for more - * details. - */ -static void hwprobe_arch_id(struct riscv_hwprobe *pair, - const struct cpumask *cpus) -{ - u64 id = -1ULL; - bool first = true; - int cpu; - - for_each_cpu(cpu, cpus) { - u64 cpu_id; - - switch (pair->key) { - case RISCV_HWPROBE_KEY_MVENDORID: - cpu_id = riscv_cached_mvendorid(cpu); - break; - case RISCV_HWPROBE_KEY_MIMPID: - cpu_id = riscv_cached_mimpid(cpu); - break; - case RISCV_HWPROBE_KEY_MARCHID: - cpu_id = riscv_cached_marchid(cpu); - break; - } - - if (first) { - id = cpu_id; - first = false; - } - - /* - * If there's a mismatch for the given set, return -1 in the - * value. - */ - if (id != cpu_id) { - id = -1ULL; - break; - } - } - - pair->value = id; -} - -static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, - const struct cpumask *cpus) -{ - int cpu; - u64 missing = 0; - - pair->value = 0; - if (has_fpu()) - pair->value |= RISCV_HWPROBE_IMA_FD; - - if (riscv_isa_extension_available(NULL, c)) - pair->value |= RISCV_HWPROBE_IMA_C; - - if (has_vector()) - pair->value |= RISCV_HWPROBE_IMA_V; - - /* - * Loop through and record extensions that 1) anyone has, and 2) anyone - * doesn't have. - */ - for_each_cpu(cpu, cpus) { - struct riscv_isainfo *isainfo = &hart_isa[cpu]; - - if (riscv_isa_extension_available(isainfo->isa, ZBA)) - pair->value |= RISCV_HWPROBE_EXT_ZBA; - else - missing |= RISCV_HWPROBE_EXT_ZBA; - - if (riscv_isa_extension_available(isainfo->isa, ZBB)) - pair->value |= RISCV_HWPROBE_EXT_ZBB; - else - missing |= RISCV_HWPROBE_EXT_ZBB; - - if (riscv_isa_extension_available(isainfo->isa, ZBS)) - pair->value |= RISCV_HWPROBE_EXT_ZBS; - else - missing |= RISCV_HWPROBE_EXT_ZBS; - } - - /* Now turn off reporting features if any CPU is missing it. */ - pair->value &= ~missing; -} - -static u64 hwprobe_misaligned(const struct cpumask *cpus) -{ - int cpu; - u64 perf = -1ULL; - - for_each_cpu(cpu, cpus) { - int this_perf = per_cpu(misaligned_access_speed, cpu); - - if (perf == -1ULL) - perf = this_perf; - - if (perf != this_perf) { - perf = RISCV_HWPROBE_MISALIGNED_UNKNOWN; - break; - } - } - - if (perf == -1ULL) - return RISCV_HWPROBE_MISALIGNED_UNKNOWN; - - return perf; -} - -static void hwprobe_one_pair(struct riscv_hwprobe *pair, - const struct cpumask *cpus) -{ - switch (pair->key) { - case RISCV_HWPROBE_KEY_MVENDORID: - case RISCV_HWPROBE_KEY_MARCHID: - case RISCV_HWPROBE_KEY_MIMPID: - hwprobe_arch_id(pair, cpus); - break; - /* - * The kernel already assumes that the base single-letter ISA - * extensions are supported on all harts, and only supports the - * IMA base, so just cheat a bit here and tell that to - * userspace. - */ - case RISCV_HWPROBE_KEY_BASE_BEHAVIOR: - pair->value = RISCV_HWPROBE_BASE_BEHAVIOR_IMA; - break; - - case RISCV_HWPROBE_KEY_IMA_EXT_0: - hwprobe_isa_ext0(pair, cpus); - break; - - case RISCV_HWPROBE_KEY_CPUPERF_0: - pair->value = hwprobe_misaligned(cpus); - break; - - /* - * For forward compatibility, unknown keys don't fail the whole - * call, but get their element key set to -1 and value set to 0 - * indicating they're unrecognized. - */ - default: - pair->key = -1; - pair->value = 0; - break; - } -} - -static int do_riscv_hwprobe(struct riscv_hwprobe __user *pairs, - size_t pair_count, size_t cpusetsize, - unsigned long __user *cpus_user, - unsigned int flags) -{ - size_t out; - int ret; - cpumask_t cpus; - - /* Check the reserved flags. */ - if (flags != 0) - return -EINVAL; - - /* - * The interface supports taking in a CPU mask, and returns values that - * are consistent across that mask. Allow userspace to specify NULL and - * 0 as a shortcut to all online CPUs. - */ - cpumask_clear(&cpus); - if (!cpusetsize && !cpus_user) { - cpumask_copy(&cpus, cpu_online_mask); - } else { - if (cpusetsize > cpumask_size()) - cpusetsize = cpumask_size(); - - ret = copy_from_user(&cpus, cpus_user, cpusetsize); - if (ret) - return -EFAULT; - - /* - * Userspace must provide at least one online CPU, without that - * there's no way to define what is supported. - */ - cpumask_and(&cpus, &cpus, cpu_online_mask); - if (cpumask_empty(&cpus)) - return -EINVAL; - } - - for (out = 0; out < pair_count; out++, pairs++) { - struct riscv_hwprobe pair; - - if (get_user(pair.key, &pairs->key)) - return -EFAULT; - - pair.value = 0; - hwprobe_one_pair(&pair, &cpus); - ret = put_user(pair.key, &pairs->key); - if (ret == 0) - ret = put_user(pair.value, &pairs->value); - - if (ret) - return -EFAULT; - } - - return 0; -} - -#ifdef CONFIG_MMU - -static int __init init_hwprobe_vdso_data(void) -{ - struct vdso_data *vd = __arch_get_k_vdso_data(); - struct arch_vdso_data *avd = &vd->arch_data; - u64 id_bitsmash = 0; - struct riscv_hwprobe pair; - int key; - - /* - * Initialize vDSO data with the answers for the "all CPUs" case, to - * save a syscall in the common case. - */ - for (key = 0; key <= RISCV_HWPROBE_MAX_KEY; key++) { - pair.key = key; - hwprobe_one_pair(&pair, cpu_online_mask); - - WARN_ON_ONCE(pair.key < 0); - - avd->all_cpu_hwprobe_values[key] = pair.value; - /* - * Smash together the vendor, arch, and impl IDs to see if - * they're all 0 or any negative. - */ - if (key <= RISCV_HWPROBE_KEY_MIMPID) - id_bitsmash |= pair.value; - } - - /* - * If the arch, vendor, and implementation ID are all the same across - * all harts, then assume all CPUs are the same, and allow the vDSO to - * answer queries for arbitrary masks. However if all values are 0 (not - * populated) or any value returns -1 (varies across CPUs), then the - * vDSO should defer to the kernel for exotic cpu masks. - */ - avd->homogeneous_cpus = id_bitsmash != 0 && id_bitsmash != -1; - return 0; -} - -arch_initcall_sync(init_hwprobe_vdso_data); - -#endif /* CONFIG_MMU */ - -SYSCALL_DEFINE5(riscv_hwprobe, struct riscv_hwprobe __user *, pairs, - size_t, pair_count, size_t, cpusetsize, unsigned long __user *, - cpus, unsigned int, flags) -{ - return do_riscv_hwprobe(pairs, pair_count, cpusetsize, - cpus, flags); -} - /* Not defined using SYSCALL_DEFINE0 to avoid error injection */ asmlinkage long __riscv_sys_ni_syscall(const struct pt_regs *__unused) {

[v1,2/6] RISC-V: Move the hwprobe syscall to its own file

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