1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/arch/arm/vfp/vfpmodule.c
5 * Copyright (C) 2004 ARM Limited.
6 * Written by Deep Blue Solutions Limited.
8 #include <linux/types.h>
10 #include <linux/cpu_pm.h>
11 #include <linux/hardirq.h>
12 #include <linux/kernel.h>
13 #include <linux/notifier.h>
14 #include <linux/signal.h>
15 #include <linux/sched/signal.h>
16 #include <linux/smp.h>
17 #include <linux/init.h>
18 #include <linux/uaccess.h>
19 #include <linux/user.h>
20 #include <linux/export.h>
23 #include <asm/cputype.h>
24 #include <asm/system_info.h>
25 #include <asm/thread_notify.h>
26 #include <asm/traps.h>
33 * Our undef handlers (in entry.S)
35 asmlinkage void vfp_support_entry(void);
36 asmlinkage void vfp_null_entry(void);
38 asmlinkage void (*vfp_vector)(void) = vfp_null_entry;
42 * Used in startup: set to non-zero if VFP checks fail
43 * After startup, holds VFP architecture
45 static unsigned int __initdata VFP_arch;
48 * The pointer to the vfpstate structure of the thread which currently
49 * owns the context held in the VFP hardware, or NULL if the hardware
52 * For UP, this is sufficient to tell which thread owns the VFP context.
53 * However, for SMP, we also need to check the CPU number stored in the
54 * saved state too to catch migrations.
56 union vfp_state *vfp_current_hw_state[NR_CPUS];
59 * Is 'thread's most up to date state stored in this CPUs hardware?
60 * Must be called from non-preemptible context.
62 static bool vfp_state_in_hw(unsigned int cpu, struct thread_info *thread)
65 if (thread->vfpstate.hard.cpu != cpu)
68 return vfp_current_hw_state[cpu] == &thread->vfpstate;
72 * Force a reload of the VFP context from the thread structure. We do
73 * this by ensuring that access to the VFP hardware is disabled, and
74 * clear vfp_current_hw_state. Must be called from non-preemptible context.
76 static void vfp_force_reload(unsigned int cpu, struct thread_info *thread)
78 if (vfp_state_in_hw(cpu, thread)) {
79 fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
80 vfp_current_hw_state[cpu] = NULL;
83 thread->vfpstate.hard.cpu = NR_CPUS;
88 * Per-thread VFP initialization.
90 static void vfp_thread_flush(struct thread_info *thread)
92 union vfp_state *vfp = &thread->vfpstate;
96 * Disable VFP to ensure we initialize it first. We must ensure
97 * that the modification of vfp_current_hw_state[] and hardware
98 * disable are done for the same CPU and without preemption.
100 * Do this first to ensure that preemption won't overwrite our
101 * state saving should access to the VFP be enabled at this point.
104 if (vfp_current_hw_state[cpu] == vfp)
105 vfp_current_hw_state[cpu] = NULL;
106 fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
109 memset(vfp, 0, sizeof(union vfp_state));
111 vfp->hard.fpexc = FPEXC_EN;
112 vfp->hard.fpscr = FPSCR_ROUND_NEAREST;
114 vfp->hard.cpu = NR_CPUS;
118 static void vfp_thread_exit(struct thread_info *thread)
120 /* release case: Per-thread VFP cleanup. */
121 union vfp_state *vfp = &thread->vfpstate;
122 unsigned int cpu = get_cpu();
124 if (vfp_current_hw_state[cpu] == vfp)
125 vfp_current_hw_state[cpu] = NULL;
129 static void vfp_thread_copy(struct thread_info *thread)
131 struct thread_info *parent = current_thread_info();
133 vfp_sync_hwstate(parent);
134 thread->vfpstate = parent->vfpstate;
136 thread->vfpstate.hard.cpu = NR_CPUS;
141 * When this function is called with the following 'cmd's, the following
142 * is true while this function is being run:
143 * THREAD_NOFTIFY_SWTICH:
144 * - the previously running thread will not be scheduled onto another CPU.
145 * - the next thread to be run (v) will not be running on another CPU.
146 * - thread->cpu is the local CPU number
147 * - not preemptible as we're called in the middle of a thread switch
148 * THREAD_NOTIFY_FLUSH:
149 * - the thread (v) will be running on the local CPU, so
150 * v === current_thread_info()
151 * - thread->cpu is the local CPU number at the time it is accessed,
152 * but may change at any time.
153 * - we could be preempted if tree preempt rcu is enabled, so
154 * it is unsafe to use thread->cpu.
156 * - we could be preempted if tree preempt rcu is enabled, so
157 * it is unsafe to use thread->cpu.
159 static int vfp_notifier(struct notifier_block *self, unsigned long cmd, void *v)
161 struct thread_info *thread = v;
168 case THREAD_NOTIFY_SWITCH:
175 * On SMP, if VFP is enabled, save the old state in
176 * case the thread migrates to a different CPU. The
177 * restoring is done lazily.
179 if ((fpexc & FPEXC_EN) && vfp_current_hw_state[cpu])
180 vfp_save_state(vfp_current_hw_state[cpu], fpexc);
184 * Always disable VFP so we can lazily save/restore the
187 fmxr(FPEXC, fpexc & ~FPEXC_EN);
190 case THREAD_NOTIFY_FLUSH:
191 vfp_thread_flush(thread);
194 case THREAD_NOTIFY_EXIT:
195 vfp_thread_exit(thread);
198 case THREAD_NOTIFY_COPY:
199 vfp_thread_copy(thread);
206 static struct notifier_block vfp_notifier_block = {
207 .notifier_call = vfp_notifier,
211 * Raise a SIGFPE for the current process.
212 * sicode describes the signal being raised.
214 static void vfp_raise_sigfpe(unsigned int sicode, struct pt_regs *regs)
217 * This is the same as NWFPE, because it's not clear what
220 current->thread.error_code = 0;
221 current->thread.trap_no = 6;
223 send_sig_fault(SIGFPE, sicode,
224 (void __user *)(instruction_pointer(regs) - 4),
228 static void vfp_panic(char *reason, u32 inst)
232 pr_err("VFP: Error: %s\n", reason);
233 pr_err("VFP: EXC 0x%08x SCR 0x%08x INST 0x%08x\n",
234 fmrx(FPEXC), fmrx(FPSCR), inst);
235 for (i = 0; i < 32; i += 2)
236 pr_err("VFP: s%2u: 0x%08x s%2u: 0x%08x\n",
237 i, vfp_get_float(i), i+1, vfp_get_float(i+1));
241 * Process bitmask of exception conditions.
243 static void vfp_raise_exceptions(u32 exceptions, u32 inst, u32 fpscr, struct pt_regs *regs)
247 pr_debug("VFP: raising exceptions %08x\n", exceptions);
249 if (exceptions == VFP_EXCEPTION_ERROR) {
250 vfp_panic("unhandled bounce", inst);
251 vfp_raise_sigfpe(FPE_FLTINV, regs);
256 * If any of the status flags are set, update the FPSCR.
257 * Comparison instructions always return at least one of
260 if (exceptions & (FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V))
261 fpscr &= ~(FPSCR_N|FPSCR_Z|FPSCR_C|FPSCR_V);
267 #define RAISE(stat,en,sig) \
268 if (exceptions & stat && fpscr & en) \
272 * These are arranged in priority order, least to highest.
274 RAISE(FPSCR_DZC, FPSCR_DZE, FPE_FLTDIV);
275 RAISE(FPSCR_IXC, FPSCR_IXE, FPE_FLTRES);
276 RAISE(FPSCR_UFC, FPSCR_UFE, FPE_FLTUND);
277 RAISE(FPSCR_OFC, FPSCR_OFE, FPE_FLTOVF);
278 RAISE(FPSCR_IOC, FPSCR_IOE, FPE_FLTINV);
281 vfp_raise_sigfpe(si_code, regs);
285 * Emulate a VFP instruction.
287 static u32 vfp_emulate_instruction(u32 inst, u32 fpscr, struct pt_regs *regs)
289 u32 exceptions = VFP_EXCEPTION_ERROR;
291 pr_debug("VFP: emulate: INST=0x%08x SCR=0x%08x\n", inst, fpscr);
293 if (INST_CPRTDO(inst)) {
294 if (!INST_CPRT(inst)) {
298 if (vfp_single(inst)) {
299 exceptions = vfp_single_cpdo(inst, fpscr);
301 exceptions = vfp_double_cpdo(inst, fpscr);
305 * A CPRT instruction can not appear in FPINST2, nor
306 * can it cause an exception. Therefore, we do not
307 * have to emulate it.
312 * A CPDT instruction can not appear in FPINST2, nor can
313 * it cause an exception. Therefore, we do not have to
317 return exceptions & ~VFP_NAN_FLAG;
321 * Package up a bounce condition.
323 void VFP_bounce(u32 trigger, u32 fpexc, struct pt_regs *regs)
325 u32 fpscr, orig_fpscr, fpsid, exceptions;
327 pr_debug("VFP: bounce: trigger %08x fpexc %08x\n", trigger, fpexc);
330 * At this point, FPEXC can have the following configuration:
333 * 0 1 x - synchronous exception
334 * 1 x 0 - asynchronous exception
335 * 1 x 1 - sychronous on VFP subarch 1 and asynchronous on later
336 * 0 0 1 - synchronous on VFP9 (non-standard subarch 1
337 * implementation), undefined otherwise
339 * Clear various bits and enable access to the VFP so we can
342 fmxr(FPEXC, fpexc & ~(FPEXC_EX|FPEXC_DEX|FPEXC_FP2V|FPEXC_VV|FPEXC_TRAP_MASK));
345 orig_fpscr = fpscr = fmrx(FPSCR);
348 * Check for the special VFP subarch 1 and FPSCR.IXE bit case
350 if ((fpsid & FPSID_ARCH_MASK) == (1 << FPSID_ARCH_BIT)
351 && (fpscr & FPSCR_IXE)) {
353 * Synchronous exception, emulate the trigger instruction
358 if (fpexc & FPEXC_EX) {
359 #ifndef CONFIG_CPU_FEROCEON
361 * Asynchronous exception. The instruction is read from FPINST
362 * and the interrupted instruction has to be restarted.
364 trigger = fmrx(FPINST);
367 } else if (!(fpexc & FPEXC_DEX)) {
369 * Illegal combination of bits. It can be caused by an
370 * unallocated VFP instruction but with FPSCR.IXE set and not
373 vfp_raise_exceptions(VFP_EXCEPTION_ERROR, trigger, fpscr, regs);
378 * Modify fpscr to indicate the number of iterations remaining.
379 * If FPEXC.EX is 0, FPEXC.DEX is 1 and the FPEXC.VV bit indicates
380 * whether FPEXC.VECITR or FPSCR.LEN is used.
382 if (fpexc & (FPEXC_EX | FPEXC_VV)) {
385 len = fpexc + (1 << FPEXC_LENGTH_BIT);
387 fpscr &= ~FPSCR_LENGTH_MASK;
388 fpscr |= (len & FPEXC_LENGTH_MASK) << (FPSCR_LENGTH_BIT - FPEXC_LENGTH_BIT);
392 * Handle the first FP instruction. We used to take note of the
393 * FPEXC bounce reason, but this appears to be unreliable.
394 * Emulate the bounced instruction instead.
396 exceptions = vfp_emulate_instruction(trigger, fpscr, regs);
398 vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs);
401 * If there isn't a second FP instruction, exit now. Note that
402 * the FPEXC.FP2V bit is valid only if FPEXC.EX is 1.
404 if ((fpexc & (FPEXC_EX | FPEXC_FP2V)) != (FPEXC_EX | FPEXC_FP2V))
408 * The barrier() here prevents fpinst2 being read
409 * before the condition above.
412 trigger = fmrx(FPINST2);
415 exceptions = vfp_emulate_instruction(trigger, orig_fpscr, regs);
417 vfp_raise_exceptions(exceptions, trigger, orig_fpscr, regs);
422 static void vfp_enable(void *unused)
426 BUG_ON(preemptible());
427 access = get_copro_access();
430 * Enable full access to VFP (cp10 and cp11)
432 set_copro_access(access | CPACC_FULL(10) | CPACC_FULL(11));
435 /* Called by platforms on which we want to disable VFP because it may not be
436 * present on all CPUs within a SMP complex. Needs to be called prior to
439 void __init vfp_disable(void)
442 pr_debug("%s: should be called prior to vfp_init\n", __func__);
449 static int vfp_pm_suspend(void)
451 struct thread_info *ti = current_thread_info();
452 u32 fpexc = fmrx(FPEXC);
454 /* if vfp is on, then save state for resumption */
455 if (fpexc & FPEXC_EN) {
456 pr_debug("%s: saving vfp state\n", __func__);
457 vfp_save_state(&ti->vfpstate, fpexc);
459 /* disable, just in case */
460 fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
461 } else if (vfp_current_hw_state[ti->cpu]) {
463 fmxr(FPEXC, fpexc | FPEXC_EN);
464 vfp_save_state(vfp_current_hw_state[ti->cpu], fpexc);
469 /* clear any information we had about last context state */
470 vfp_current_hw_state[ti->cpu] = NULL;
475 static void vfp_pm_resume(void)
477 /* ensure we have access to the vfp */
480 /* and disable it to ensure the next usage restores the state */
481 fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
484 static int vfp_cpu_pm_notifier(struct notifier_block *self, unsigned long cmd,
491 case CPU_PM_ENTER_FAILED:
499 static struct notifier_block vfp_cpu_pm_notifier_block = {
500 .notifier_call = vfp_cpu_pm_notifier,
503 static void vfp_pm_init(void)
505 cpu_pm_register_notifier(&vfp_cpu_pm_notifier_block);
509 static inline void vfp_pm_init(void) { }
510 #endif /* CONFIG_CPU_PM */
513 * Ensure that the VFP state stored in 'thread->vfpstate' is up to date
514 * with the hardware state.
516 void vfp_sync_hwstate(struct thread_info *thread)
518 unsigned int cpu = get_cpu();
520 if (vfp_state_in_hw(cpu, thread)) {
521 u32 fpexc = fmrx(FPEXC);
524 * Save the last VFP state on this CPU.
526 fmxr(FPEXC, fpexc | FPEXC_EN);
527 vfp_save_state(&thread->vfpstate, fpexc | FPEXC_EN);
534 /* Ensure that the thread reloads the hardware VFP state on the next use. */
535 void vfp_flush_hwstate(struct thread_info *thread)
537 unsigned int cpu = get_cpu();
539 vfp_force_reload(cpu, thread);
545 * Save the current VFP state into the provided structures and prepare
546 * for entry into a new function (signal handler).
548 int vfp_preserve_user_clear_hwstate(struct user_vfp *ufp,
549 struct user_vfp_exc *ufp_exc)
551 struct thread_info *thread = current_thread_info();
552 struct vfp_hard_struct *hwstate = &thread->vfpstate.hard;
554 /* Ensure that the saved hwstate is up-to-date. */
555 vfp_sync_hwstate(thread);
558 * Copy the floating point registers. There can be unused
559 * registers see asm/hwcap.h for details.
561 memcpy(&ufp->fpregs, &hwstate->fpregs, sizeof(hwstate->fpregs));
564 * Copy the status and control register.
566 ufp->fpscr = hwstate->fpscr;
569 * Copy the exception registers.
571 ufp_exc->fpexc = hwstate->fpexc;
572 ufp_exc->fpinst = hwstate->fpinst;
573 ufp_exc->fpinst2 = hwstate->fpinst2;
575 /* Ensure that VFP is disabled. */
576 vfp_flush_hwstate(thread);
579 * As per the PCS, clear the length and stride bits for function
582 hwstate->fpscr &= ~(FPSCR_LENGTH_MASK | FPSCR_STRIDE_MASK);
586 /* Sanitise and restore the current VFP state from the provided structures. */
587 int vfp_restore_user_hwstate(struct user_vfp *ufp, struct user_vfp_exc *ufp_exc)
589 struct thread_info *thread = current_thread_info();
590 struct vfp_hard_struct *hwstate = &thread->vfpstate.hard;
593 /* Disable VFP to avoid corrupting the new thread state. */
594 vfp_flush_hwstate(thread);
597 * Copy the floating point registers. There can be unused
598 * registers see asm/hwcap.h for details.
600 memcpy(&hwstate->fpregs, &ufp->fpregs, sizeof(hwstate->fpregs));
602 * Copy the status and control register.
604 hwstate->fpscr = ufp->fpscr;
607 * Sanitise and restore the exception registers.
609 fpexc = ufp_exc->fpexc;
611 /* Ensure the VFP is enabled. */
614 /* Ensure FPINST2 is invalid and the exception flag is cleared. */
615 fpexc &= ~(FPEXC_EX | FPEXC_FP2V);
616 hwstate->fpexc = fpexc;
618 hwstate->fpinst = ufp_exc->fpinst;
619 hwstate->fpinst2 = ufp_exc->fpinst2;
625 * VFP hardware can lose all context when a CPU goes offline.
626 * As we will be running in SMP mode with CPU hotplug, we will save the
627 * hardware state at every thread switch. We clear our held state when
628 * a CPU has been killed, indicating that the VFP hardware doesn't contain
629 * a threads VFP state. When a CPU starts up, we re-enable access to the
630 * VFP hardware. The callbacks below are called on the CPU which
631 * is being offlined/onlined.
633 static int vfp_dying_cpu(unsigned int cpu)
635 vfp_current_hw_state[cpu] = NULL;
639 static int vfp_starting_cpu(unsigned int unused)
645 #ifdef CONFIG_KERNEL_MODE_NEON
647 static int vfp_kmode_exception(struct pt_regs *regs, unsigned int instr)
650 * If we reach this point, a floating point exception has been raised
651 * while running in kernel mode. If the NEON/VFP unit was enabled at the
652 * time, it means a VFP instruction has been issued that requires
653 * software assistance to complete, something which is not currently
654 * supported in kernel mode.
655 * If the NEON/VFP unit was disabled, and the location pointed to below
656 * is properly preceded by a call to kernel_neon_begin(), something has
657 * caused the task to be scheduled out and back in again. In this case,
658 * rebuilding and running with CONFIG_DEBUG_ATOMIC_SLEEP enabled should
659 * be helpful in localizing the problem.
661 if (fmrx(FPEXC) & FPEXC_EN)
662 pr_crit("BUG: unsupported FP instruction in kernel mode\n");
664 pr_crit("BUG: FP instruction issued in kernel mode with FP unit disabled\n");
665 pr_crit("FPEXC == 0x%08x\n", fmrx(FPEXC));
669 static struct undef_hook vfp_kmode_exception_hook[] = {{
670 .instr_mask = 0xfe000000,
671 .instr_val = 0xf2000000,
672 .cpsr_mask = MODE_MASK | PSR_T_BIT,
673 .cpsr_val = SVC_MODE,
674 .fn = vfp_kmode_exception,
676 .instr_mask = 0xff100000,
677 .instr_val = 0xf4000000,
678 .cpsr_mask = MODE_MASK | PSR_T_BIT,
679 .cpsr_val = SVC_MODE,
680 .fn = vfp_kmode_exception,
682 .instr_mask = 0xef000000,
683 .instr_val = 0xef000000,
684 .cpsr_mask = MODE_MASK | PSR_T_BIT,
685 .cpsr_val = SVC_MODE | PSR_T_BIT,
686 .fn = vfp_kmode_exception,
688 .instr_mask = 0xff100000,
689 .instr_val = 0xf9000000,
690 .cpsr_mask = MODE_MASK | PSR_T_BIT,
691 .cpsr_val = SVC_MODE | PSR_T_BIT,
692 .fn = vfp_kmode_exception,
694 .instr_mask = 0x0c000e00,
695 .instr_val = 0x0c000a00,
696 .cpsr_mask = MODE_MASK,
697 .cpsr_val = SVC_MODE,
698 .fn = vfp_kmode_exception,
701 static int __init vfp_kmode_exception_hook_init(void)
705 for (i = 0; i < ARRAY_SIZE(vfp_kmode_exception_hook); i++)
706 register_undef_hook(&vfp_kmode_exception_hook[i]);
709 subsys_initcall(vfp_kmode_exception_hook_init);
712 * Kernel-side NEON support functions
714 void kernel_neon_begin(void)
716 struct thread_info *thread = current_thread_info();
721 * Kernel mode NEON is only allowed outside of interrupt context
722 * with preemption disabled. This will make sure that the kernel
723 * mode NEON register contents never need to be preserved.
725 BUG_ON(in_interrupt());
728 fpexc = fmrx(FPEXC) | FPEXC_EN;
732 * Save the userland NEON/VFP state. Under UP,
733 * the owner could be a task other than 'current'
735 if (vfp_state_in_hw(cpu, thread))
736 vfp_save_state(&thread->vfpstate, fpexc);
738 else if (vfp_current_hw_state[cpu] != NULL)
739 vfp_save_state(vfp_current_hw_state[cpu], fpexc);
741 vfp_current_hw_state[cpu] = NULL;
743 EXPORT_SYMBOL(kernel_neon_begin);
745 void kernel_neon_end(void)
747 /* Disable the NEON/VFP unit. */
748 fmxr(FPEXC, fmrx(FPEXC) & ~FPEXC_EN);
751 EXPORT_SYMBOL(kernel_neon_end);
753 #endif /* CONFIG_KERNEL_MODE_NEON */
755 static int __init vfp_detect(struct pt_regs *regs, unsigned int instr)
757 VFP_arch = UINT_MAX; /* mark as not present */
762 static struct undef_hook vfp_detect_hook __initdata = {
763 .instr_mask = 0x0c000e00,
764 .instr_val = 0x0c000a00,
765 .cpsr_mask = MODE_MASK,
766 .cpsr_val = SVC_MODE,
771 * VFP support code initialisation.
773 static int __init vfp_init(void)
776 unsigned int cpu_arch = cpu_architecture();
779 * Enable the access to the VFP on all online CPUs so the
780 * following test on FPSID will succeed.
782 if (cpu_arch >= CPU_ARCH_ARMv6)
783 on_each_cpu(vfp_enable, NULL, 1);
786 * First check that there is a VFP that we can use.
787 * The handler is already setup to just log calls, so
788 * we just need to read the VFPSID register.
790 register_undef_hook(&vfp_detect_hook);
792 vfpsid = fmrx(FPSID);
794 unregister_undef_hook(&vfp_detect_hook);
795 vfp_vector = vfp_null_entry;
797 pr_info("VFP support v0.3: ");
799 pr_cont("not present\n");
801 /* Extract the architecture on CPUID scheme */
802 } else if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) {
803 VFP_arch = vfpsid & FPSID_CPUID_ARCH_MASK;
804 VFP_arch >>= FPSID_ARCH_BIT;
806 * Check for the presence of the Advanced SIMD
807 * load/store instructions, integer and single
808 * precision floating point operations. Only check
809 * for NEON if the hardware has the MVFR registers.
811 if (IS_ENABLED(CONFIG_NEON) &&
812 (fmrx(MVFR1) & 0x000fff00) == 0x00011100)
813 elf_hwcap |= HWCAP_NEON;
815 if (IS_ENABLED(CONFIG_VFPv3)) {
816 u32 mvfr0 = fmrx(MVFR0);
817 if (((mvfr0 & MVFR0_DP_MASK) >> MVFR0_DP_BIT) == 0x2 ||
818 ((mvfr0 & MVFR0_SP_MASK) >> MVFR0_SP_BIT) == 0x2) {
819 elf_hwcap |= HWCAP_VFPv3;
821 * Check for VFPv3 D16 and VFPv4 D16. CPUs in
822 * this configuration only have 16 x 64bit
825 if ((mvfr0 & MVFR0_A_SIMD_MASK) == 1)
827 elf_hwcap |= HWCAP_VFPv3D16;
829 elf_hwcap |= HWCAP_VFPD32;
832 if ((fmrx(MVFR1) & 0xf0000000) == 0x10000000)
833 elf_hwcap |= HWCAP_VFPv4;
835 /* Extract the architecture version on pre-cpuid scheme */
837 if (vfpsid & FPSID_NODOUBLE) {
838 pr_cont("no double precision support\n");
842 VFP_arch = (vfpsid & FPSID_ARCH_MASK) >> FPSID_ARCH_BIT;
845 cpuhp_setup_state_nocalls(CPUHP_AP_ARM_VFP_STARTING,
846 "arm/vfp:starting", vfp_starting_cpu,
849 vfp_vector = vfp_support_entry;
851 thread_register_notifier(&vfp_notifier_block);
855 * We detected VFP, and the support code is
856 * in place; report VFP support to userspace.
858 elf_hwcap |= HWCAP_VFP;
860 pr_cont("implementor %02x architecture %d part %02x variant %x rev %x\n",
861 (vfpsid & FPSID_IMPLEMENTER_MASK) >> FPSID_IMPLEMENTER_BIT,
863 (vfpsid & FPSID_PART_MASK) >> FPSID_PART_BIT,
864 (vfpsid & FPSID_VARIANT_MASK) >> FPSID_VARIANT_BIT,
865 (vfpsid & FPSID_REV_MASK) >> FPSID_REV_BIT);
870 core_initcall(vfp_init);