/*
 * linux/ipc/msgutil.c
 * Copyright (C) 1999, 2004 Manfred Spraul
 *
 * This file is released under GNU General Public Licence version 2 or
 * (at your option) any later version.
 *
 * See the file COPYING for more details.
 */

#include <linux/spinlock.h>
#include <linux/init.h>
#include <linux/security.h>
#include <linux/slab.h>
#include <linux/ipc.h>
#include <linux/msg.h>
#include <linux/ipc_namespace.h>
#include <linux/utsname.h>
#include <linux/proc_ns.h>
#include <linux/uaccess.h>
#include <linux/dma-mapping.h>
#include <linux/mempool.h>
#include <litmus/cache_proc.h>
#include <litmus/trace.h>
#include <litmus/litmus.h>
#include <asm/cacheflush.h>

#include "util.h"

DEFINE_SPINLOCK(mq_lock);

/*
 * The next 2 defines are here bc this is the only file
 * compiled when either CONFIG_SYSVIPC and CONFIG_POSIX_MQUEUE
 * and not CONFIG_IPC_NS.
 */
struct ipc_namespace init_ipc_ns = {
	.count		= ATOMIC_INIT(1),
	.user_ns = &init_user_ns,
	.ns.inum = PROC_IPC_INIT_INO,
#ifdef CONFIG_IPC_NS
	.ns.ops = &ipcns_operations,
#endif
};

atomic_t nr_ipc_ns = ATOMIC_INIT(1);

struct msg_msgseg {
	struct msg_msgseg *next;
	/* the next part of the message follows immediately */
	dma_addr_t	seg_handle;
	size_t seg_len;
};

#define DATALEN_MSG	((size_t)PAGE_SIZE-sizeof(struct msg_msg))
#define DATALEN_SEG	((size_t)PAGE_SIZE-sizeof(struct msg_msgseg))

static dma_addr_t handle;

mempool_t *msgpool;
extern void *msgvaddr;

static struct msg_msg *alloc_msg(size_t len, long mtype)
{
	struct msg_msg *msg;
	struct msg_msgseg **pseg;
	size_t alen;
	int n_seg = 0;

	alen = min(len, DATALEN_MSG);
	if (mtype == 1) {
		//printk(KERN_INFO "SBP message\n");
		msg = dma_alloc_coherent(NULL, sizeof(*msg) + alen, &handle, GFP_KERNEL|GFP_COLOR|GFP_CPU1);
		msg->handle = handle;
		msg->alloc_len = sizeof(*msg) + alen;
	} else if (mtype == 2) {
		msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL|GFP_COLOR);
	} else {
		//msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
		msg = msgvaddr;
	}
	if (msg == NULL)
		return NULL;

	msg->next = NULL;
	msg->security = NULL;

	len -= alen;
	pseg = &msg->next;
	while (len > 0) {
		struct msg_msgseg *seg;
		alen = min(len, DATALEN_SEG);
		if (mtype == 1) {
			seg = dma_alloc_coherent(NULL, sizeof(*seg) + alen, &handle, GFP_KERNEL|GFP_COLOR|GFP_CPU1);
			seg->seg_handle = handle;
			seg->seg_len = alen;
			//printk(KERN_INFO "SBP message seg %d\n", seg->seg_len);
		} else if (mtype == 2) {
			seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL|GFP_COLOR);
		} else {
			//seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL);
			n_seg++;
			seg = msgvaddr + PAGE_SIZE*n_seg;
		}
		if (seg == NULL)
			goto out_err;
		*pseg = seg;
		seg->next = NULL;
		pseg = &seg->next;
		len -= alen;
	}

	return msg;

out_err:
	free_msg(msg);
	return NULL;
}

struct msg_msg *load_msg(const void __user *src, size_t len, long mtype)
{
	struct msg_msg *msg;
	struct msg_msgseg *seg;
	int err = -EFAULT;
	size_t alen;

TS_NET_RX_SOFTIRQ_START;	
	msg = alloc_msg(len, mtype);
	if (msg == NULL)
		return ERR_PTR(-ENOMEM);

	alen = min(len, DATALEN_MSG);

	if (copy_from_user(msg + 1, src, alen))
		goto out_err;

	for (seg = msg->next; seg != NULL; seg = seg->next) {
		len -= alen;
		src = (char __user *)src + alen;
		alen = min(len, DATALEN_SEG);
		if (copy_from_user(seg + 1, src, alen))
			goto out_err;
	}
TS_NET_RX_SOFTIRQ_END;
/*	if (mtype == 3) {
		cache_lockdown(0xFFFF8000, smp_processor_id());
	}
*/
	err = security_msg_msg_alloc(msg);
	if (err)
		goto out_err;

	return msg;

out_err:
	free_msg(msg);
	return ERR_PTR(err);
}
#ifdef CONFIG_CHECKPOINT_RESTORE
struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
{
	struct msg_msgseg *dst_pseg, *src_pseg;
	size_t len = src->m_ts;
	size_t alen;

	BUG_ON(dst == NULL);
	if (src->m_ts > dst->m_ts)
		return ERR_PTR(-EINVAL);

	alen = min(len, DATALEN_MSG);
	memcpy(dst + 1, src + 1, alen);

	for (dst_pseg = dst->next, src_pseg = src->next;
	     src_pseg != NULL;
	     dst_pseg = dst_pseg->next, src_pseg = src_pseg->next) {

		len -= alen;
		alen = min(len, DATALEN_SEG);
		memcpy(dst_pseg + 1, src_pseg + 1, alen);
	}

	dst->m_type = src->m_type;
	dst->m_ts = src->m_ts;

	return dst;
}
#else
struct msg_msg *copy_msg(struct msg_msg *src, struct msg_msg *dst)
{
	return ERR_PTR(-ENOSYS);
}
#endif
int store_msg(void __user *dest, struct msg_msg *msg, size_t len)
{
	size_t alen;
	struct msg_msgseg *seg;

	alen = min(len, DATALEN_MSG);
	if (copy_to_user(dest, msg + 1, alen))
		return -1;

	for (seg = msg->next; seg != NULL; seg = seg->next) {
		len -= alen;
		dest = (char __user *)dest + alen;
		alen = min(len, DATALEN_SEG);
		if (copy_to_user(dest, seg + 1, alen))
			return -1;
	}
	return 0;
}

void free_msg(struct msg_msg *msg)
{
	struct msg_msgseg *seg;
	long mtype = msg->m_type;
	
	security_msg_msg_free(msg);

	seg = msg->next;
	if (mtype == 1) {
		//printk(KERN_INFO "free_msg(): SBP message\n");
		dma_free_coherent(NULL, msg->alloc_len, msg, msg->handle);
	} else if (mtype != 3) {
		kfree(msg);
	}
	while (seg != NULL) {
		struct msg_msgseg *tmp = seg->next;
		if (mtype == 1) {
			//printk(KERN_INFO "free_msg(): SBP message seg %d\n", seg->seg_len);
			dma_free_coherent(NULL, sizeof(*seg)+(seg->seg_len), seg, seg->seg_handle);
		} else if (mtype != 3)
			kfree(seg);
		seg = tmp;
	}
}