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/*
* Copyright (C) 2006-2009 Free Software Foundation
*
* 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 the program ; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <sys/types.h>
#include <mach/vm_param.h>
#include <machine/spl.h>
#include <vm/pmap.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include "grant.h"
#define NR_RESERVED_ENTRIES 8
#define NR_GRANT_PAGES 4
decl_simple_lock_data(static,lock);
static struct grant_entry *grants;
static vm_map_entry_t grants_map_entry;
static int last_grant = NR_RESERVED_ENTRIES;
static grant_ref_t free_grants = -1;
static grant_ref_t grant_alloc(void) {
grant_ref_t grant;
if (free_grants != -1) {
grant = free_grants;
free_grants = grants[grant].frame;
} else {
grant = last_grant++;
if (grant == (NR_GRANT_PAGES * PAGE_SIZE)/sizeof(*grants))
panic("not enough grant entries, increase NR_GRANT_PAGES");
}
return grant;
}
static void grant_free(grant_ref_t grant) {
grants[grant].frame = free_grants;
free_grants = grant;
}
static grant_ref_t grant_set(domid_t domid, unsigned long mfn, uint16_t flags) {
spl_t spl = splhigh();
simple_lock(&lock);
grant_ref_t grant = grant_alloc();
grants[grant].domid = domid;
grants[grant].frame = mfn;
wmb();
grants[grant].flags = flags;
simple_unlock(&lock);
splx(spl);
return grant;
}
grant_ref_t hyp_grant_give(domid_t domid, unsigned long frame, int readonly) {
return grant_set(domid, pfn_to_mfn(frame),
GTF_permit_access | (readonly ? GTF_readonly : 0));
}
grant_ref_t hyp_grant_accept_transfer(domid_t domid, unsigned long frame) {
return grant_set(domid, frame, GTF_accept_transfer);
}
unsigned long hyp_grant_finish_transfer(grant_ref_t grant) {
unsigned long frame;
spl_t spl = splhigh();
simple_lock(&lock);
if (!(grants[grant].flags & GTF_transfer_committed))
panic("grant transfer %x not committed\n", grant);
while (!(grants[grant].flags & GTF_transfer_completed))
machine_relax();
rmb();
frame = grants[grant].frame;
grant_free(grant);
simple_unlock(&lock);
splx(spl);
return frame;
}
void hyp_grant_takeback(grant_ref_t grant) {
spl_t spl = splhigh();
simple_lock(&lock);
if (grants[grant].flags & (GTF_reading|GTF_writing))
panic("grant %d still in use (%lx)\n", grant, grants[grant].flags);
/* Note: this is not safe, a cmpxchg is needed, see grant_table.h */
grants[grant].flags = 0;
wmb();
grant_free(grant);
simple_unlock(&lock);
splx(spl);
}
void *hyp_grant_address(grant_ref_t grant) {
return &grants[grant];
}
void hyp_grant_init(void) {
struct gnttab_setup_table setup;
unsigned long frame[NR_GRANT_PAGES];
long ret;
int i;
vm_offset_t addr;
setup.dom = DOMID_SELF;
setup.nr_frames = NR_GRANT_PAGES;
setup.frame_list = (void*) kvtolin(frame);
ret = hyp_grant_table_op(GNTTABOP_setup_table, kvtolin(&setup), 1);
if (ret)
panic("setup grant table error %d", ret);
if (setup.status)
panic("setup grant table: %d\n", setup.status);
simple_lock_init(&lock);
vm_map_find_entry(kernel_map, &addr, NR_GRANT_PAGES * PAGE_SIZE,
(vm_offset_t) 0, kernel_object, &grants_map_entry);
grants = (void*) addr;
for (i = 0; i < NR_GRANT_PAGES; i++)
pmap_map_mfn((void *)grants + i * PAGE_SIZE, frame[i]);
}
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