// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/thread_info.h>
#include <linux/uaccess.h>
#include <linux/errno.h>

#include <asm/sigcontext.h>
#include <asm/fpumacro.h>
#include <asm/ptrace.h>
#include <asm/switch_to.h>

#include "sigutil.h"

int save_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
        unsigned long *fpregs = current_thread_info()->fpregs;
        unsigned long fprs;
        int err = 0;
        
        fprs = current_thread_info()->fpsaved[0];
        if (fprs & FPRS_DL)
                err |= copy_to_user(&fpu->si_float_regs[0], fpregs,
                                    (sizeof(unsigned int) * 32));
        if (fprs & FPRS_DU)
                err |= copy_to_user(&fpu->si_float_regs[32], fpregs+16,
                                    (sizeof(unsigned int) * 32));
        err |= __put_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
        err |= __put_user(current_thread_info()->gsr[0], &fpu->si_gsr);
        err |= __put_user(fprs, &fpu->si_fprs);

        return err;
}

int restore_fpu_state(struct pt_regs *regs, __siginfo_fpu_t __user *fpu)
{
        unsigned long *fpregs = current_thread_info()->fpregs;
        unsigned long fprs;
        int err;

        if (((unsigned long) fpu) & 7)
                return -EFAULT;

        err = get_user(fprs, &fpu->si_fprs);
        fprs_write(0);
        regs->tstate &= ~TSTATE_PEF;
        if (fprs & FPRS_DL)
                err |= copy_from_user(fpregs, &fpu->si_float_regs[0],
                               (sizeof(unsigned int) * 32));
        if (fprs & FPRS_DU)
                err |= copy_from_user(fpregs+16, &fpu->si_float_regs[32],
                               (sizeof(unsigned int) * 32));
        err |= __get_user(current_thread_info()->xfsr[0], &fpu->si_fsr);
        err |= __get_user(current_thread_info()->gsr[0], &fpu->si_gsr);
        current_thread_info()->fpsaved[0] |= fprs;
        return err;
}

int save_rwin_state(int wsaved, __siginfo_rwin_t __user *rwin)
{
        int i, err = __put_user(wsaved, &rwin->wsaved);

        for (i = 0; i < wsaved; i++) {
                struct reg_window *rp = &current_thread_info()->reg_window[i];
                unsigned long fp = current_thread_info()->rwbuf_stkptrs[i];

                err |= copy_to_user(&rwin->reg_window[i], rp,
                                    sizeof(struct reg_window));
                err |= __put_user(fp, &rwin->rwbuf_stkptrs[i]);
        }
        return err;
}

int restore_rwin_state(__siginfo_rwin_t __user *rp)
{
        struct thread_info *t = current_thread_info();
        int i, wsaved, err;

        if (((unsigned long) rp) & 7)
                return -EFAULT;

        get_user(wsaved, &rp->wsaved);
        if (wsaved > NSWINS)
                return -EFAULT;

        err = 0;
        for (i = 0; i < wsaved; i++) {
                err |= copy_from_user(&t->reg_window[i],
                                      &rp->reg_window[i],
                                      sizeof(struct reg_window));
                err |= __get_user(t->rwbuf_stkptrs[i],
                                  &rp->rwbuf_stkptrs[i]);
        }
        if (err)
                return err;

        set_thread_wsaved(wsaved);
        synchronize_user_stack();
        if (get_thread_wsaved())
                return -EFAULT;
        return 0;
}