Make has_vector take one argument. This argument represents the minimum Vector subextension that the following Vector actions assume.
Also, change riscv_v_first_use_handler(), and boot code that calls riscv_v_setup_vsize() to accept the minimum Vector sub-extension, ZVE32X.
Most kernel/user interfaces requires minimum of ZVE32X. Thus, programs compiled and run with ZVE32X should be supported by the kernel on most aspects. This includes context-switch, signal, ptrace, prctl, and hwprobe.
One exception is that ELF_HWCAP returns 'V' only if full V is supported on the platform. This means that the system without a full V must not rely on ELF_HWCAP to tell whether it is allowable to execute Vector without first invoking a prctl() check.
Signed-off-by: Andy Chiu andy.chiu@sifive.com Acked-by: Joel Granados j.granados@samsung.com --- Changelog v4: - check static_assert for !CONFIG_RISCV_ISA_V case in has_vector. Changelog v2: - update the comment in hwprobe. --- arch/riscv/include/asm/switch_to.h | 2 +- arch/riscv/include/asm/vector.h | 25 ++++++++++++++++--------- arch/riscv/include/asm/xor.h | 2 +- arch/riscv/kernel/cpufeature.c | 5 ++++- arch/riscv/kernel/kernel_mode_vector.c | 4 ++-- arch/riscv/kernel/process.c | 4 ++-- arch/riscv/kernel/signal.c | 6 +++--- arch/riscv/kernel/smpboot.c | 2 +- arch/riscv/kernel/sys_hwprobe.c | 8 ++++++-- arch/riscv/kernel/vector.c | 15 +++++++++------ arch/riscv/lib/uaccess.S | 2 +- 11 files changed, 46 insertions(+), 29 deletions(-)
diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h index 7efdb0584d47..df1adf196c4f 100644 --- a/arch/riscv/include/asm/switch_to.h +++ b/arch/riscv/include/asm/switch_to.h @@ -78,7 +78,7 @@ do { \ struct task_struct *__next = (next); \ if (has_fpu()) \ __switch_to_fpu(__prev, __next); \ - if (has_vector()) \ + if (has_vector(ZVE32X)) \ __switch_to_vector(__prev, __next); \ ((last) = __switch_to(__prev, __next)); \ } while (0) diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index 731dcd0ed4de..ed5fb6515d54 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -8,6 +8,19 @@
#include <linux/types.h> #include <uapi/asm-generic/errno.h> +#include <asm/cpufeature.h> +#include <asm/hwcap.h> + +#define has_vector(VEXT) \ +({ \ + static_assert(RISCV_ISA_EXT_##VEXT == RISCV_ISA_EXT_ZVE32X || \ + RISCV_ISA_EXT_##VEXT == RISCV_ISA_EXT_ZVE32F || \ + RISCV_ISA_EXT_##VEXT == RISCV_ISA_EXT_ZVE64X || \ + RISCV_ISA_EXT_##VEXT == RISCV_ISA_EXT_ZVE64F || \ + RISCV_ISA_EXT_##VEXT == RISCV_ISA_EXT_ZVE64D || \ + RISCV_ISA_EXT_##VEXT == RISCV_ISA_EXT_v); \ + IS_ENABLED(CONFIG_RISCV_ISA_V) && riscv_has_extension_unlikely(RISCV_ISA_EXT_##VEXT); \ +})
#ifdef CONFIG_RISCV_ISA_V
@@ -15,9 +28,9 @@ #include <linux/sched.h> #include <linux/sched/task_stack.h> #include <asm/ptrace.h> -#include <asm/cpufeature.h> #include <asm/csr.h> #include <asm/asm.h> +#include <asm/bug.h>
extern unsigned long riscv_v_vsize; int riscv_v_setup_vsize(void); @@ -35,11 +48,6 @@ static inline u32 riscv_v_flags(void) return READ_ONCE(current->thread.riscv_v_flags); }
-static __always_inline bool has_vector(void) -{ - return riscv_has_extension_unlikely(RISCV_ISA_EXT_v); -} - static inline void __riscv_v_vstate_clean(struct pt_regs *regs) { regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN; @@ -131,7 +139,7 @@ static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_ riscv_v_enable(); asm volatile ( ".option push\n\t" - ".option arch, +v\n\t" + ".option arch, +zve32x\n\t" "vsetvli %0, x0, e8, m8, ta, ma\n\t" "vle8.v v0, (%1)\n\t" "add %1, %1, %0\n\t" @@ -153,7 +161,7 @@ static inline void __riscv_v_vstate_discard(void) riscv_v_enable(); asm volatile ( ".option push\n\t" - ".option arch, +v\n\t" + ".option arch, +zve32x\n\t" "vsetvli %0, x0, e8, m8, ta, ma\n\t" "vmv.v.i v0, -1\n\t" "vmv.v.i v8, -1\n\t" @@ -267,7 +275,6 @@ bool riscv_v_vstate_ctrl_user_allowed(void); struct pt_regs;
static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; } -static __always_inline bool has_vector(void) { return false; } static inline bool riscv_v_first_use_handler(struct pt_regs *regs) { return false; } static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; } static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; } diff --git a/arch/riscv/include/asm/xor.h b/arch/riscv/include/asm/xor.h index 96011861e46b..46042ef5a2f7 100644 --- a/arch/riscv/include/asm/xor.h +++ b/arch/riscv/include/asm/xor.h @@ -61,7 +61,7 @@ static struct xor_block_template xor_block_rvv = { do { \ xor_speed(&xor_block_8regs); \ xor_speed(&xor_block_32regs); \ - if (has_vector()) { \ + if (has_vector(ZVE32X)) { \ xor_speed(&xor_block_rvv);\ } \ } while (0) diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 38d09de518b1..8b52060649d2 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -715,12 +715,15 @@ void __init riscv_fill_hwcap(void) elf_hwcap &= ~COMPAT_HWCAP_ISA_F; }
- if (elf_hwcap & COMPAT_HWCAP_ISA_V) { + if (__riscv_isa_extension_available(NULL, RISCV_ISA_EXT_ZVE32X)) { /* * This callsite can't fail here. It cannot fail when called on * the boot hart. */ riscv_v_setup_vsize(); + } + + if (elf_hwcap & COMPAT_HWCAP_ISA_V) { /* * ISA string in device tree might have 'v' flag, but * CONFIG_RISCV_ISA_V is disabled in kernel. diff --git a/arch/riscv/kernel/kernel_mode_vector.c b/arch/riscv/kernel/kernel_mode_vector.c index 6afe80c7f03a..0d4d1a03d1c7 100644 --- a/arch/riscv/kernel/kernel_mode_vector.c +++ b/arch/riscv/kernel/kernel_mode_vector.c @@ -208,7 +208,7 @@ void kernel_vector_begin(void) { bool nested = false;
- if (WARN_ON(!has_vector())) + if (WARN_ON(!has_vector(ZVE32X))) return;
BUG_ON(!may_use_simd()); @@ -236,7 +236,7 @@ EXPORT_SYMBOL_GPL(kernel_vector_begin); */ void kernel_vector_end(void) { - if (WARN_ON(!has_vector())) + if (WARN_ON(!has_vector(ZVE32X))) return;
riscv_v_disable(); diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 92922dbd5b5c..919e72f9fff6 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -178,7 +178,7 @@ void flush_thread(void) void arch_release_task_struct(struct task_struct *tsk) { /* Free the vector context of datap. */ - if (has_vector()) + if (has_vector(ZVE32X)) riscv_v_thread_free(tsk); }
@@ -225,7 +225,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) p->thread.s[0] = 0; } p->thread.riscv_v_flags = 0; - if (has_vector()) + if (has_vector(ZVE32X)) riscv_v_thread_alloc(p); p->thread.ra = (unsigned long)ret_from_fork; p->thread.sp = (unsigned long)childregs; /* kernel sp */ diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index 501e66debf69..a96e6e969a3f 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -188,7 +188,7 @@ static long restore_sigcontext(struct pt_regs *regs,
return 0; case RISCV_V_MAGIC: - if (!has_vector() || !riscv_v_vstate_query(regs) || + if (!has_vector(ZVE32X) || !riscv_v_vstate_query(regs) || size != riscv_v_sc_size) return -EINVAL;
@@ -210,7 +210,7 @@ static size_t get_rt_frame_size(bool cal_all)
frame_size = sizeof(*frame);
- if (has_vector()) { + if (has_vector(ZVE32X)) { if (cal_all || riscv_v_vstate_query(task_pt_regs(current))) total_context_size += riscv_v_sc_size; } @@ -283,7 +283,7 @@ static long setup_sigcontext(struct rt_sigframe __user *frame, if (has_fpu()) err |= save_fp_state(regs, &sc->sc_fpregs); /* Save the vector state. */ - if (has_vector() && riscv_v_vstate_query(regs)) + if (has_vector(ZVE32X) && riscv_v_vstate_query(regs)) err |= save_v_state(regs, (void __user **)&sc_ext_ptr); /* Write zero to fp-reserved space and check it on restore_sigcontext */ err |= __put_user(0, &sc->sc_extdesc.reserved); diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 673437ccc13d..7252666ce0da 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -214,7 +214,7 @@ asmlinkage __visible void smp_callin(void) struct mm_struct *mm = &init_mm; unsigned int curr_cpuid = smp_processor_id();
- if (has_vector()) { + if (has_vector(ZVE32X)) { /* * Return as early as possible so the hart with a mismatching * vlen won't boot. diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c index c8219b82fbfc..e7c3fcac62a1 100644 --- a/arch/riscv/kernel/sys_hwprobe.c +++ b/arch/riscv/kernel/sys_hwprobe.c @@ -69,7 +69,7 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, if (riscv_isa_extension_available(NULL, c)) pair->value |= RISCV_HWPROBE_IMA_C;
- if (has_vector()) + if (has_vector(v)) pair->value |= RISCV_HWPROBE_IMA_V;
/* @@ -112,7 +112,11 @@ static void hwprobe_isa_ext0(struct riscv_hwprobe *pair, EXT_KEY(ZACAS); EXT_KEY(ZICOND);
- if (has_vector()) { + /* + * Vector crypto and ZVE* extensions are supported only if + * kernel has minimum V support of ZVE32X. + */ + if (has_vector(ZVE32X)) { EXT_KEY(ZVE32X); EXT_KEY(ZVE32F); EXT_KEY(ZVE64X); diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c index 6727d1d3b8f2..e8a47fa72351 100644 --- a/arch/riscv/kernel/vector.c +++ b/arch/riscv/kernel/vector.c @@ -53,7 +53,7 @@ int riscv_v_setup_vsize(void)
void __init riscv_v_setup_ctx_cache(void) { - if (!has_vector()) + if (!has_vector(ZVE32X)) return;
riscv_v_user_cachep = kmem_cache_create_usercopy("riscv_vector_ctx", @@ -173,8 +173,11 @@ bool riscv_v_first_use_handler(struct pt_regs *regs) u32 __user *epc = (u32 __user *)regs->epc; u32 insn = (u32)regs->badaddr;
+ if (!has_vector(ZVE32X)) + return false; + /* Do not handle if V is not supported, or disabled */ - if (!(ELF_HWCAP & COMPAT_HWCAP_ISA_V)) + if (!riscv_v_vstate_ctrl_user_allowed()) return false;
/* If V has been enabled then it is not the first-use trap */ @@ -213,7 +216,7 @@ void riscv_v_vstate_ctrl_init(struct task_struct *tsk) bool inherit; int cur, next;
- if (!has_vector()) + if (!has_vector(ZVE32X)) return;
next = riscv_v_ctrl_get_next(tsk); @@ -235,7 +238,7 @@ void riscv_v_vstate_ctrl_init(struct task_struct *tsk)
long riscv_v_vstate_ctrl_get_current(void) { - if (!has_vector()) + if (!has_vector(ZVE32X)) return -EINVAL;
return current->thread.vstate_ctrl & PR_RISCV_V_VSTATE_CTRL_MASK; @@ -246,7 +249,7 @@ long riscv_v_vstate_ctrl_set_current(unsigned long arg) bool inherit; int cur, next;
- if (!has_vector()) + if (!has_vector(ZVE32X)) return -EINVAL;
if (arg & ~PR_RISCV_V_VSTATE_CTRL_MASK) @@ -296,7 +299,7 @@ static struct ctl_table riscv_v_default_vstate_table[] = {
static int __init riscv_v_sysctl_init(void) { - if (has_vector()) + if (has_vector(ZVE32X)) if (!register_sysctl("abi", riscv_v_default_vstate_table)) return -EINVAL; return 0; diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index bc22c078aba8..bbe143bb32a0 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -14,7 +14,7 @@
SYM_FUNC_START(__asm_copy_to_user) #ifdef CONFIG_RISCV_ISA_V - ALTERNATIVE("j fallback_scalar_usercopy", "nop", 0, RISCV_ISA_EXT_v, CONFIG_RISCV_ISA_V) + ALTERNATIVE("j fallback_scalar_usercopy", "nop", 0, RISCV_ISA_EXT_ZVE32X, CONFIG_RISCV_ISA_V) REG_L t0, riscv_v_usercopy_threshold bltu a2, t0, fallback_scalar_usercopy tail enter_vector_usercopy