xen: import arch generic part of xencomm

obj-y	+= grant-table.o features.o events.o

obj-y	+= xenbus/

obj-$(CONFIG_XEN_XENCOMM)	+= xencomm.o

/*

 * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

 *

 * Copyright (C) IBM Corp. 2006

 *

 * Authors: Hollis Blanchard <hollisb@us.ibm.com>

 */

#include <linux/gfp.h>

#include <linux/mm.h>

#include <asm/page.h>

#include <xen/xencomm.h>

#include <xen/interface/xen.h>

#ifdef __ia64__

#include <asm/xen/xencomm.h>	/* for is_kern_addr() */

#endif

#ifdef HAVE_XEN_PLATFORM_COMPAT_H

#include <xen/platform-compat.h>

#endif

static int xencomm_init(struct xencomm_desc *desc,

			void *buffer, unsigned long bytes)

{

	unsigned long recorded = 0;

	int i = 0;

	while ((recorded < bytes) && (i < desc->nr_addrs)) {

		unsigned long vaddr = (unsigned long)buffer + recorded;

		unsigned long paddr;

		int offset;

		int chunksz;

		offset = vaddr % PAGE_SIZE; /* handle partial pages */

		chunksz = min(PAGE_SIZE - offset, bytes - recorded);

		paddr = xencomm_vtop(vaddr);

		if (paddr == ~0UL) {

			printk(KERN_DEBUG "%s: couldn't translate vaddr %lx\n",

			       __func__, vaddr);

			return -EINVAL;

		}

		desc->address[i++] = paddr;

		recorded += chunksz;

	}

	if (recorded < bytes) {

		printk(KERN_DEBUG

		       "%s: could only translate %ld of %ld bytes\n",

		       __func__, recorded, bytes);

		return -ENOSPC;

	}

	/* mark remaining addresses invalid (just for safety) */

	while (i < desc->nr_addrs)

		desc->address[i++] = XENCOMM_INVALID;

	desc->magic = XENCOMM_MAGIC;

	return 0;

}

static struct xencomm_desc *xencomm_alloc(gfp_t gfp_mask,

					  void *buffer, unsigned long bytes)

{

	struct xencomm_desc *desc;

	unsigned long buffer_ulong = (unsigned long)buffer;

	unsigned long start = buffer_ulong & PAGE_MASK;

	unsigned long end = (buffer_ulong + bytes) | ~PAGE_MASK;

	unsigned long nr_addrs = (end - start + 1) >> PAGE_SHIFT;

	unsigned long size = sizeof(*desc) +

		sizeof(desc->address[0]) * nr_addrs;

	/*

	 * slab allocator returns at least sizeof(void*) aligned pointer.

	 * When sizeof(*desc) > sizeof(void*), struct xencomm_desc might

	 * cross page boundary.

	 */

	if (sizeof(*desc) > sizeof(void *)) {

		unsigned long order = get_order(size);

		desc = (struct xencomm_desc *)__get_free_pages(gfp_mask,

							       order);

		if (desc == NULL)

			return NULL;

		desc->nr_addrs =

			((PAGE_SIZE << order) - sizeof(struct xencomm_desc)) /

			sizeof(*desc->address);

	} else {

		desc = kmalloc(size, gfp_mask);

		if (desc == NULL)

			return NULL;

		desc->nr_addrs = nr_addrs;

	}

	return desc;

}

void xencomm_free(struct xencomm_handle *desc)

{

	if (desc && !((ulong)desc & XENCOMM_INLINE_FLAG)) {

		struct xencomm_desc *desc__ = (struct xencomm_desc *)desc;

		if (sizeof(*desc__) > sizeof(void *)) {

			unsigned long size = sizeof(*desc__) +

				sizeof(desc__->address[0]) * desc__->nr_addrs;

			unsigned long order = get_order(size);

			free_pages((unsigned long)__va(desc), order);

		} else

			kfree(__va(desc));

	}

}

static int xencomm_create(void *buffer, unsigned long bytes,

			  struct xencomm_desc **ret, gfp_t gfp_mask)

{

	struct xencomm_desc *desc;

	int rc;

	pr_debug("%s: %p[%ld]\n", __func__, buffer, bytes);

	if (bytes == 0) {

		/* don't create a descriptor; Xen recognizes NULL. */

		BUG_ON(buffer != NULL);

		*ret = NULL;

		return 0;

	}

	BUG_ON(buffer == NULL); /* 'bytes' is non-zero */

	desc = xencomm_alloc(gfp_mask, buffer, bytes);

	if (!desc) {

		printk(KERN_DEBUG "%s failure\n", "xencomm_alloc");

		return -ENOMEM;

	}

	rc = xencomm_init(desc, buffer, bytes);

	if (rc) {

		printk(KERN_DEBUG "%s failure: %d\n", "xencomm_init", rc);

		xencomm_free((struct xencomm_handle *)__pa(desc));

		return rc;

	}

	*ret = desc;

	return 0;

}

/* check if memory address is within VMALLOC region  */

static int is_phys_contiguous(unsigned long addr)

{

	if (!is_kernel_addr(addr))

		return 0;

	return (addr < VMALLOC_START) || (addr >= VMALLOC_END);

}

static struct xencomm_handle *xencomm_create_inline(void *ptr)

{

	unsigned long paddr;

	BUG_ON(!is_phys_contiguous((unsigned long)ptr));

	paddr = (unsigned long)xencomm_pa(ptr);

	BUG_ON(paddr & XENCOMM_INLINE_FLAG);

	return (struct xencomm_handle *)(paddr | XENCOMM_INLINE_FLAG);

}

/* "mini" routine, for stack-based communications: */

static int xencomm_create_mini(void *buffer,

	unsigned long bytes, struct xencomm_mini *xc_desc,

	struct xencomm_desc **ret)

{

	int rc = 0;

	struct xencomm_desc *desc;

	BUG_ON(((unsigned long)xc_desc) % sizeof(*xc_desc) != 0);

	desc = (void *)xc_desc;

	desc->nr_addrs = XENCOMM_MINI_ADDRS;

	rc = xencomm_init(desc, buffer, bytes);

	if (!rc)

		*ret = desc;

	return rc;

}

struct xencomm_handle *xencomm_map(void *ptr, unsigned long bytes)

{

	int rc;

	struct xencomm_desc *desc;

	if (is_phys_contiguous((unsigned long)ptr))

		return xencomm_create_inline(ptr);

	rc = xencomm_create(ptr, bytes, &desc, GFP_KERNEL);

	if (rc || desc == NULL)

		return NULL;

	return xencomm_pa(desc);

}

struct xencomm_handle *__xencomm_map_no_alloc(void *ptr, unsigned long bytes,

			struct xencomm_mini *xc_desc)

{

	int rc;

	struct xencomm_desc *desc = NULL;

	if (is_phys_contiguous((unsigned long)ptr))

		return xencomm_create_inline(ptr);

	rc = xencomm_create_mini(ptr, bytes, xc_desc,

				&desc);

	if (rc)

		return NULL;

	return xencomm_pa(desc);

}

/*

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to

 * deal in the Software without restriction, including without limitation the

 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or

 * sell copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE

 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER

 * DEALINGS IN THE SOFTWARE.

 *

 * Copyright (C) IBM Corp. 2006

 */

#ifndef _XEN_XENCOMM_H_

#define _XEN_XENCOMM_H_

/* A xencomm descriptor is a scatter/gather list containing physical

 * addresses corresponding to a virtually contiguous memory area. The

 * hypervisor translates these physical addresses to machine addresses to copy

 * to and from the virtually contiguous area.

 */

#define XENCOMM_MAGIC 0x58434F4D /* 'XCOM' */

#define XENCOMM_INVALID (~0UL)

struct xencomm_desc {

    uint32_t magic;

    uint32_t nr_addrs; /* the number of entries in address[] */

    uint64_t address[0];

};

#endif /* _XEN_XENCOMM_H_ */

/*

 * 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 of the License, 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

 *

 * Copyright (C) IBM Corp. 2006

 *

 * Authors: Hollis Blanchard <hollisb@us.ibm.com>

 *          Jerone Young <jyoung5@us.ibm.com>

 */

#ifndef _LINUX_XENCOMM_H_

#define _LINUX_XENCOMM_H_

#include <xen/interface/xencomm.h>

#define XENCOMM_MINI_ADDRS 3

struct xencomm_mini {

	struct xencomm_desc _desc;

	uint64_t address[XENCOMM_MINI_ADDRS];

};

/* To avoid additionnal virt to phys conversion, an opaque structure is

   presented.  */

struct xencomm_handle;

extern void xencomm_free(struct xencomm_handle *desc);

extern struct xencomm_handle *xencomm_map(void *ptr, unsigned long bytes);

extern struct xencomm_handle *__xencomm_map_no_alloc(void *ptr,

			unsigned long bytes,  struct xencomm_mini *xc_area);

#if 0

#define XENCOMM_MINI_ALIGNED(xc_desc, n)				\

	struct xencomm_mini xc_desc ## _base[(n)]			\

	__attribute__((__aligned__(sizeof(struct xencomm_mini))));	\

	struct xencomm_mini *xc_desc = &xc_desc ## _base[0];

#else

/*

 * gcc bug workaround:

 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16660

 * gcc doesn't handle properly stack variable with

 * __attribute__((__align__(sizeof(struct xencomm_mini))))

 */

#define XENCOMM_MINI_ALIGNED(xc_desc, n)				\

	unsigned char xc_desc ## _base[((n) + 1 ) *			\

				       sizeof(struct xencomm_mini)];	\

	struct xencomm_mini *xc_desc = (struct xencomm_mini *)		\

		((unsigned long)xc_desc ## _base +			\

		 (sizeof(struct xencomm_mini) -				\

		  ((unsigned long)xc_desc ## _base) %			\

		  sizeof(struct xencomm_mini)));

#endif

#define xencomm_map_no_alloc(ptr, bytes)			\

	({ XENCOMM_MINI_ALIGNED(xc_desc, 1);			\

		__xencomm_map_no_alloc(ptr, bytes, xc_desc); })

/* provided by architecture code: */

extern unsigned long xencomm_vtop(unsigned long vaddr);

static inline void *xencomm_pa(void *ptr)

{

	return (void *)xencomm_vtop((unsigned long)ptr);

}

#define xen_guest_handle(hnd)  ((hnd).p)

#endif /* _LINUX_XENCOMM_H_ */