/**
 * Copyright (c) 2018 Anup Patel.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * @file riscv_sbi.h
 * @author Anup Patel (anup@brainfault.org)
 * @brief Supervisor binary interface (SBI)
 *
 * The source has been largely adapted from Linux 4.x or higher:
 * arch/riscv/include/asm/sbi.h
 *
 * Copyright (C) 2015 Regents of the University of California
 *
 * The original code is licensed under the GPL.
 */

#ifndef __RISCV_SBI_H__
#define __RISCV_SBI_H__

#include <vmm_types.h>

#define SBI_SET_TIMER 0
#define SBI_CONSOLE_PUTCHAR 1
#define SBI_CONSOLE_GETCHAR 2
#define SBI_CLEAR_IPI 3
#define SBI_SEND_IPI 4
#define SBI_REMOTE_FENCE_I 5
#define SBI_REMOTE_SFENCE_VMA 6
#define SBI_REMOTE_SFENCE_VMA_ASID 7
#define SBI_SHUTDOWN 8

#define SBI_CALL(which, arg0, arg1, arg2) ({				\
	register unsigned long a0 asm ("a0") = (unsigned long)(arg0);	\
	register unsigned long a1 asm ("a1") = (unsigned long)(arg1);	\
	register unsigned long a2 asm ("a2") = (unsigned long)(arg2);	\
	register unsigned long a7 asm ("a7") = (unsigned long)(which);	\
	asm volatile ("ecall"						\
		      : "+r" (a0)					\
		      : "r" (a1), "r" (a2), "r" (a7)			\
		      : "memory");					\
	a0;								\
})

/* Lazy implementations until SBI is finalized */
#define SBI_CALL_0(which) SBI_CALL(which, 0, 0, 0)
#define SBI_CALL_1(which, arg0) SBI_CALL(which, arg0, 0, 0)
#define SBI_CALL_2(which, arg0, arg1) SBI_CALL(which, arg0, arg1, 0)

static inline void sbi_console_putchar(int ch)
{
	SBI_CALL_1(SBI_CONSOLE_PUTCHAR, ch);
}

static inline int sbi_console_getchar(void)
{
	return SBI_CALL_0(SBI_CONSOLE_GETCHAR);
}

static inline void sbi_set_timer(u64 stime_value)
{
#if __riscv_xlen == 32
	SBI_CALL_2(SBI_SET_TIMER, stime_value, stime_value >> 32);
#else
	SBI_CALL_1(SBI_SET_TIMER, stime_value);
#endif
}

static inline void sbi_shutdown(void)
{
	SBI_CALL_0(SBI_SHUTDOWN);
}

static inline void sbi_clear_ipi(void)
{
	SBI_CALL_0(SBI_CLEAR_IPI);
}

static inline void sbi_send_ipi(const unsigned long *hart_mask)
{
	SBI_CALL_1(SBI_SEND_IPI, hart_mask);
}

static inline void sbi_remote_fence_i(const unsigned long *hart_mask)
{
	SBI_CALL_1(SBI_REMOTE_FENCE_I, hart_mask);
}

static inline void sbi_remote_sfence_vma(const unsigned long *hart_mask,
					 unsigned long start,
					 unsigned long size)
{
	SBI_CALL_1(SBI_REMOTE_SFENCE_VMA, hart_mask);
}

static inline void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask,
					      unsigned long start,
					      unsigned long size,
					      unsigned long asid)
{
	SBI_CALL_1(SBI_REMOTE_SFENCE_VMA_ASID, hart_mask);
}

#endif
