/*
 * Copyright (c) 2015-2020 François Tigeot <ftigeot@wolfpond.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _LINUX_GFP_H_
#define _LINUX_GFP_H_

#include <linux/mmdebug.h>
#include <linux/mmzone.h>
#include <linux/stddef.h>

#include <sys/malloc.h>
#include <vm/vm_page.h>
#include <machine/bus_dma.h>

#define GFP_NOWAIT	(M_NOWAIT | M_CACHEALIGN)
#define GFP_ATOMIC	(M_NOWAIT | M_CACHEALIGN)
#define GFP_KERNEL	(M_WAITOK | M_CACHEALIGN)
#define GFP_TEMPORARY	GFP_KERNEL
#define GFP_USER	GFP_KERNEL
#define GFP_HIGHUSER	GFP_KERNEL

#define __GFP_ZERO		M_ZERO
#define __GFP_NORETRY		M_NULLOK
#define __GFP_RETRY_MAYFAIL	M_NULLOK

#define __GFP_HIGHMEM		0u	/* No particular meaning on DragonFly */
#define __GFP_IO		0u	/* No particular meaning on DragonFly */
#define __GFP_RECLAIM		0u
#define __GFP_RECLAIMABLE	0u
#define __GFP_NOWARN		0u
#define __GFP_NOFAIL		0u

#define __GFP_DMA32	0x10000u	/* XXX: MUST NOT collide with the M_XXX definitions */
#define GFP_DMA32	__GFP_DMA32

static inline void __free_page(struct page *page)
{
	vm_page_free_contig((struct vm_page *)page, PAGE_SIZE);
}

static inline struct page * alloc_page(int flags)
{
	vm_paddr_t high = ~0LLU;

	if (flags & GFP_DMA32)
		high = BUS_SPACE_MAXADDR_32BIT;

	return (struct page *)vm_page_alloc_contig(0LLU, ~0LLU,
			PAGE_SIZE, PAGE_SIZE, PAGE_SIZE,
			VM_MEMATTR_DEFAULT);
}

static inline bool
gfpflags_allow_blocking(const gfp_t flags)
{
	return (flags & M_WAITOK);
}

/*
 * Allocate multiple contiguous pages. The DragonFly code can only do
 * multiple allocations via the free page reserve.  Linux does not appear
 * to restrict the address space, so neither do we.
 */
static inline struct page *
alloc_pages(gfp_t gfp_mask, unsigned int order)
{
	size_t bytes = PAGE_SIZE << order;
	struct vm_page *pgs;

	pgs = vm_page_alloc_contig(0LLU, ~0LLU, bytes, bytes, bytes,
				   VM_MEMATTR_DEFAULT);

	return (struct page*)pgs;
}

/*
 * Free multiple contiguous pages
 */
static inline void
__free_pages(struct page *pgs, unsigned int order)
{
	size_t bytes = PAGE_SIZE << order;

	vm_page_free_contig((struct vm_page *)pgs, bytes);
}

#endif	/* _LINUX_GFP_H_ */