1 // SPDX-License-Identifier: GPL-2.0-only
2
3 #include <linux/mm.h>
4 #include <linux/io.h>
5
6 static ioremap_prot_hook_t ioremap_prot_hook;
7
arm64_ioremap_prot_hook_register(ioremap_prot_hook_t hook)8 int arm64_ioremap_prot_hook_register(ioremap_prot_hook_t hook)
9 {
10 if (WARN_ON(ioremap_prot_hook))
11 return -EBUSY;
12
13 ioremap_prot_hook = hook;
14 return 0;
15 }
16
ioremap_prot(phys_addr_t phys_addr,size_t size,unsigned long prot)17 void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
18 unsigned long prot)
19 {
20 unsigned long last_addr = phys_addr + size - 1;
21 pgprot_t pgprot = __pgprot(prot);
22
23 /* Don't allow outside PHYS_MASK */
24 if (last_addr & ~PHYS_MASK)
25 return NULL;
26
27 /* Don't allow RAM to be mapped. */
28 if (WARN_ON(pfn_is_map_memory(__phys_to_pfn(phys_addr))))
29 return NULL;
30
31 /*
32 * If a hook is registered (e.g. for confidential computing
33 * purposes), call that now and barf if it fails.
34 */
35 if (unlikely(ioremap_prot_hook) &&
36 WARN_ON(ioremap_prot_hook(phys_addr, size, &pgprot))) {
37 return NULL;
38 }
39
40 return generic_ioremap_prot(phys_addr, size, pgprot);
41 }
42 EXPORT_SYMBOL(ioremap_prot);
43
44 /*
45 * Must be called after early_fixmap_init
46 */
early_ioremap_init(void)47 void __init early_ioremap_init(void)
48 {
49 early_ioremap_setup();
50 }
51
arch_memremap_can_ram_remap(resource_size_t offset,size_t size,unsigned long flags)52 bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
53 unsigned long flags)
54 {
55 unsigned long pfn = PHYS_PFN(offset);
56
57 return pfn_is_map_memory(pfn);
58 }
59