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[2001:1ae9:1c2:4c00:20f:c6b4:1e57:7965]) by smtp.gmail.com with ESMTPSA id i25-20020a05640200d900b0054026e95beesm6286924edu.76.2023.11.22.08.47.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Nov 2023 08:47:03 -0800 (PST) From: Andrew Jones 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 v3 2/4] RISC-V: Move the hwprobe syscall to its own file Date: Wed, 22 Nov 2023 17:47:03 +0100 Message-ID: <20231122164700.127954-8-ajones@ventanamicro.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20231122164700.127954-6-ajones@ventanamicro.com> References: <20231122164700.127954-6-ajones@ventanamicro.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231122_084711_000783_1516B71F X-CRM114-Status: GOOD ( 29.66 ) 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 As Palmer says, hwprobe is "sort of its own thing now, and it's only going to get bigger..." Suggested-by: Palmer Dabbelt Signed-off-by: Andrew Jones Reviewed-by: Conor Dooley --- arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/sys_hwprobe.c | 289 ++++++++++++++++++++++++++++++++ arch/riscv/kernel/sys_riscv.c | 285 ------------------------------- 3 files changed, 290 insertions(+), 285 deletions(-) create mode 100644 arch/riscv/kernel/sys_hwprobe.c diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index fee22a3d1b53..a1f5dc145574 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..c0ccf1f45aaa --- /dev/null +++ b/arch/riscv/kernel/sys_hwprobe.c @@ -0,0 +1,289 @@ +// 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/arch/riscv/hwprobe.rst for + * more details. + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +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]; + +#define EXT_KEY(ext) \ + do { \ + if (__riscv_isa_extension_available(isainfo->isa, RISCV_ISA_EXT_##ext)) \ + pair->value |= RISCV_HWPROBE_EXT_##ext; \ + else \ + missing |= RISCV_HWPROBE_EXT_##ext; \ + } while (false) + + /* + * Only use EXT_KEY() for extensions which can be exposed to userspace, + * regardless of the kernel's configuration, as no other checks, besides + * presence in the hart_isa bitmap, are made. + */ + EXT_KEY(ZBA); + EXT_KEY(ZBB); + EXT_KEY(ZBS); + EXT_KEY(ZICBOZ); +#undef EXT_KEY + } + + /* Now turn off reporting features if any CPU is missing it. */ + pair->value &= ~missing; +} + +static bool hwprobe_ext0_has(const struct cpumask *cpus, unsigned long ext) +{ + struct riscv_hwprobe pair; + + hwprobe_isa_ext0(&pair, cpus); + return (pair.value & ext); +} + +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; + + case RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE: + pair->value = 0; + if (hwprobe_ext0_has(cpus, RISCV_HWPROBE_EXT_ZICBOZ)) + pair->value = riscv_cboz_block_size; + 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 5e4deb1308b8..f1c1416a9f1e 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -7,15 +7,7 @@ #include #include -#include -#include -#include -#include -#include -#include -#include #include -#include static long riscv_sys_mmap(unsigned long addr, unsigned long len, unsigned long prot, unsigned long flags, @@ -77,283 +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/arch/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]; - -#define EXT_KEY(ext) \ - do { \ - if (__riscv_isa_extension_available(isainfo->isa, RISCV_ISA_EXT_##ext)) \ - pair->value |= RISCV_HWPROBE_EXT_##ext; \ - else \ - missing |= RISCV_HWPROBE_EXT_##ext; \ - } while (false) - - /* - * Only use EXT_KEY() for extensions which can be exposed to userspace, - * regardless of the kernel's configuration, as no other checks, besides - * presence in the hart_isa bitmap, are made. - */ - EXT_KEY(ZBA); - EXT_KEY(ZBB); - EXT_KEY(ZBS); - EXT_KEY(ZICBOZ); -#undef EXT_KEY - } - - /* Now turn off reporting features if any CPU is missing it. */ - pair->value &= ~missing; -} - -static bool hwprobe_ext0_has(const struct cpumask *cpus, unsigned long ext) -{ - struct riscv_hwprobe pair; - - hwprobe_isa_ext0(&pair, cpus); - return (pair.value & ext); -} - -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; - - case RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE: - pair->value = 0; - if (hwprobe_ext0_has(cpus, RISCV_HWPROBE_EXT_ZICBOZ)) - pair->value = riscv_cboz_block_size; - 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) {