1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /******************************************************************************
6 * Granting foreign access to our memory reservation.
8 * Copyright (c) 2005-2006, Christopher Clark
9 * Copyright (c) 2004-2005, K A Fraser
10 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
11 * VA Linux Systems Japan. Split out x86 specific part.
14 #include <linux/sched.h>
16 #include <linux/slab.h>
17 #include <linux/vmalloc.h>
19 #include <xen/interface/xen.h>
21 #include <xen/grant_table.h>
25 static struct gnttab_vm_area {
26 struct vm_struct *area;
29 } gnttab_shared_vm_area, gnttab_status_vm_area;
31 int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
32 unsigned long max_nr_gframes,
35 void *shared = *__shared;
40 *__shared = shared = gnttab_shared_vm_area.area->addr;
42 addr = (unsigned long)shared;
44 for (i = 0; i < nr_gframes; i++) {
45 set_pte_at(&init_mm, addr, gnttab_shared_vm_area.ptes[i],
46 mfn_pte(frames[i], PAGE_KERNEL));
53 int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
54 unsigned long max_nr_gframes,
55 grant_status_t **__shared)
57 grant_status_t *shared = *__shared;
62 *__shared = shared = gnttab_status_vm_area.area->addr;
64 addr = (unsigned long)shared;
66 for (i = 0; i < nr_gframes; i++) {
67 set_pte_at(&init_mm, addr, gnttab_status_vm_area.ptes[i],
68 mfn_pte(frames[i], PAGE_KERNEL));
75 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes)
81 if (shared == gnttab_status_vm_area.area->addr)
82 ptes = gnttab_status_vm_area.ptes;
84 ptes = gnttab_shared_vm_area.ptes;
86 addr = (unsigned long)shared;
88 for (i = 0; i < nr_gframes; i++) {
89 set_pte_at(&init_mm, addr, ptes[i], __pte(0));
94 static int gnttab_apply(pte_t *pte, unsigned long addr, void *data)
96 struct gnttab_vm_area *area = data;
98 area->ptes[area->idx++] = pte;
102 static int arch_gnttab_valloc(struct gnttab_vm_area *area, unsigned nr_frames)
104 area->ptes = kmalloc_array(nr_frames, sizeof(*area->ptes), GFP_KERNEL);
105 if (area->ptes == NULL)
107 area->area = get_vm_area(PAGE_SIZE * nr_frames, VM_IOREMAP);
110 if (apply_to_page_range(&init_mm, (unsigned long)area->area->addr,
111 PAGE_SIZE * nr_frames, gnttab_apply, area))
112 goto out_free_vm_area;
115 free_vm_area(area->area);
121 static void arch_gnttab_vfree(struct gnttab_vm_area *area)
123 free_vm_area(area->area);
127 int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status)
131 if (!xen_pv_domain())
134 ret = arch_gnttab_valloc(&gnttab_shared_vm_area, nr_shared);
139 * Always allocate the space for the status frames in case
140 * we're migrated to a host with V2 support.
142 ret = arch_gnttab_valloc(&gnttab_status_vm_area, nr_status);
148 arch_gnttab_vfree(&gnttab_shared_vm_area);
152 #ifdef CONFIG_XEN_PVH
153 #include <xen/events.h>
154 #include <xen/xen-ops.h>
155 static int __init xen_pvh_gnttab_setup(void)
157 if (!xen_pvh_domain())
160 xen_auto_xlat_grant_frames.count = gnttab_max_grant_frames();
162 return xen_xlate_map_ballooned_pages(&xen_auto_xlat_grant_frames.pfn,
163 &xen_auto_xlat_grant_frames.vaddr,
164 xen_auto_xlat_grant_frames.count);
166 /* Call it _before_ __gnttab_init as we need to initialize the
167 * xen_auto_xlat_grant_frames first. */
168 core_initcall(xen_pvh_gnttab_setup);