GNU Linux-libre 4.14.266-gnu1
[releases.git] / arch / x86 / xen / mmu.c
1 #include <linux/pfn.h>
2 #include <asm/xen/page.h>
3 #include <asm/xen/hypercall.h>
4 #include <xen/interface/memory.h>
5
6 #include "multicalls.h"
7 #include "mmu.h"
8
9 /*
10  * Protects atomic reservation decrease/increase against concurrent increases.
11  * Also protects non-atomic updates of current_pages and balloon lists.
12  */
13 DEFINE_SPINLOCK(xen_reservation_lock);
14
15 unsigned long arbitrary_virt_to_mfn(void *vaddr)
16 {
17         xmaddr_t maddr = arbitrary_virt_to_machine(vaddr);
18
19         return PFN_DOWN(maddr.maddr);
20 }
21
22 xmaddr_t arbitrary_virt_to_machine(void *vaddr)
23 {
24         unsigned long address = (unsigned long)vaddr;
25         unsigned int level;
26         pte_t *pte;
27         unsigned offset;
28
29         /*
30          * if the PFN is in the linear mapped vaddr range, we can just use
31          * the (quick) virt_to_machine() p2m lookup
32          */
33         if (virt_addr_valid(vaddr))
34                 return virt_to_machine(vaddr);
35
36         /* otherwise we have to do a (slower) full page-table walk */
37
38         pte = lookup_address(address, &level);
39         BUG_ON(pte == NULL);
40         offset = address & ~PAGE_MASK;
41         return XMADDR(((phys_addr_t)pte_mfn(*pte) << PAGE_SHIFT) + offset);
42 }
43 EXPORT_SYMBOL_GPL(arbitrary_virt_to_machine);
44
45 static noinline void xen_flush_tlb_all(void)
46 {
47         struct mmuext_op *op;
48         struct multicall_space mcs;
49
50         preempt_disable();
51
52         mcs = xen_mc_entry(sizeof(*op));
53
54         op = mcs.args;
55         op->cmd = MMUEXT_TLB_FLUSH_ALL;
56         MULTI_mmuext_op(mcs.mc, op, 1, NULL, DOMID_SELF);
57
58         xen_mc_issue(PARAVIRT_LAZY_MMU);
59
60         preempt_enable();
61 }
62
63 #define REMAP_BATCH_SIZE 16
64
65 struct remap_data {
66         xen_pfn_t *mfn;
67         bool contiguous;
68         pgprot_t prot;
69         struct mmu_update *mmu_update;
70 };
71
72 static int remap_area_mfn_pte_fn(pte_t *ptep, pgtable_t token,
73                                  unsigned long addr, void *data)
74 {
75         struct remap_data *rmd = data;
76         pte_t pte = pte_mkspecial(mfn_pte(*rmd->mfn, rmd->prot));
77
78         /* If we have a contiguous range, just update the mfn itself,
79            else update pointer to be "next mfn". */
80         if (rmd->contiguous)
81                 (*rmd->mfn)++;
82         else
83                 rmd->mfn++;
84
85         rmd->mmu_update->ptr = virt_to_machine(ptep).maddr | MMU_NORMAL_PT_UPDATE;
86         rmd->mmu_update->val = pte_val_ma(pte);
87         rmd->mmu_update++;
88
89         return 0;
90 }
91
92 static int do_remap_gfn(struct vm_area_struct *vma,
93                         unsigned long addr,
94                         xen_pfn_t *gfn, int nr,
95                         int *err_ptr, pgprot_t prot,
96                         unsigned domid,
97                         struct page **pages)
98 {
99         int err = 0;
100         struct remap_data rmd;
101         struct mmu_update mmu_update[REMAP_BATCH_SIZE];
102         unsigned long range;
103         int mapped = 0;
104
105         BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO)));
106
107         rmd.mfn = gfn;
108         rmd.prot = prot;
109         /* We use the err_ptr to indicate if there we are doing a contiguous
110          * mapping or a discontigious mapping. */
111         rmd.contiguous = !err_ptr;
112
113         while (nr) {
114                 int index = 0;
115                 int done = 0;
116                 int batch = min(REMAP_BATCH_SIZE, nr);
117                 int batch_left = batch;
118                 range = (unsigned long)batch << PAGE_SHIFT;
119
120                 rmd.mmu_update = mmu_update;
121                 err = apply_to_page_range(vma->vm_mm, addr, range,
122                                           remap_area_mfn_pte_fn, &rmd);
123                 if (err)
124                         goto out;
125
126                 /* We record the error for each page that gives an error, but
127                  * continue mapping until the whole set is done */
128                 do {
129                         int i;
130
131                         err = HYPERVISOR_mmu_update(&mmu_update[index],
132                                                     batch_left, &done, domid);
133
134                         /*
135                          * @err_ptr may be the same buffer as @gfn, so
136                          * only clear it after each chunk of @gfn is
137                          * used.
138                          */
139                         if (err_ptr) {
140                                 for (i = index; i < index + done; i++)
141                                         err_ptr[i] = 0;
142                         }
143                         if (err < 0) {
144                                 if (!err_ptr)
145                                         goto out;
146                                 err_ptr[i] = err;
147                                 done++; /* Skip failed frame. */
148                         } else
149                                 mapped += done;
150                         batch_left -= done;
151                         index += done;
152                 } while (batch_left);
153
154                 nr -= batch;
155                 addr += range;
156                 if (err_ptr)
157                         err_ptr += batch;
158                 cond_resched();
159         }
160 out:
161
162         xen_flush_tlb_all();
163
164         return err < 0 ? err : mapped;
165 }
166
167 int xen_remap_domain_gfn_range(struct vm_area_struct *vma,
168                                unsigned long addr,
169                                xen_pfn_t gfn, int nr,
170                                pgprot_t prot, unsigned domid,
171                                struct page **pages)
172 {
173         return do_remap_gfn(vma, addr, &gfn, nr, NULL, prot, domid, pages);
174 }
175 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_range);
176
177 int xen_remap_domain_gfn_array(struct vm_area_struct *vma,
178                                unsigned long addr,
179                                xen_pfn_t *gfn, int nr,
180                                int *err_ptr, pgprot_t prot,
181                                unsigned domid, struct page **pages)
182 {
183         /* We BUG_ON because it's a programmer error to pass a NULL err_ptr,
184          * and the consequences later is quite hard to detect what the actual
185          * cause of "wrong memory was mapped in".
186          */
187         BUG_ON(err_ptr == NULL);
188         return do_remap_gfn(vma, addr, gfn, nr, err_ptr, prot, domid, pages);
189 }
190 EXPORT_SYMBOL_GPL(xen_remap_domain_gfn_array);
191
192 /* Returns: 0 success */
193 int xen_unmap_domain_gfn_range(struct vm_area_struct *vma,
194                                int numpgs, struct page **pages)
195 {
196         if (!pages || !xen_feature(XENFEAT_auto_translated_physmap))
197                 return 0;
198
199         return -EINVAL;
200 }
201 EXPORT_SYMBOL_GPL(xen_unmap_domain_gfn_range);