diff options
Diffstat (limited to 'arch/riscv/kernel/sys_riscv.c')
-rw-r--r-- | arch/riscv/kernel/sys_riscv.c | 285 |
1 files changed, 0 insertions, 285 deletions
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 <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, @@ -77,283 +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) { |