1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * OpenRISC ioremap.c |
4 | * |
5 | * Linux architectural port borrowing liberally from similar works of |
6 | * others. All original copyrights apply as per the original source |
7 | * declaration. |
8 | * |
9 | * Modifications for the OpenRISC architecture: |
10 | * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> |
11 | * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> |
12 | */ |
13 | |
14 | #include <linux/vmalloc.h> |
15 | #include <linux/io.h> |
16 | #include <linux/pgtable.h> |
17 | #include <asm/pgalloc.h> |
18 | #include <asm/fixmap.h> |
19 | #include <asm/bug.h> |
20 | #include <linux/sched.h> |
21 | #include <asm/tlbflush.h> |
22 | |
23 | extern int mem_init_done; |
24 | |
25 | /* |
26 | * OK, this one's a bit tricky... ioremap can get called before memory is |
27 | * initialized (early serial console does this) and will want to alloc a page |
28 | * for its mapping. No userspace pages will ever get allocated before memory |
29 | * is initialized so this applies only to kernel pages. In the event that |
30 | * this is called before memory is initialized we allocate the page using |
31 | * the memblock infrastructure. |
32 | */ |
33 | |
34 | pte_t __ref *pte_alloc_one_kernel(struct mm_struct *mm) |
35 | { |
36 | pte_t *pte; |
37 | |
38 | if (likely(mem_init_done)) { |
39 | pte = (pte_t *)get_zeroed_page(GFP_KERNEL); |
40 | } else { |
41 | pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE); |
42 | if (!pte) |
43 | panic(fmt: "%s: Failed to allocate %lu bytes align=0x%lx\n" , |
44 | __func__, PAGE_SIZE, PAGE_SIZE); |
45 | } |
46 | |
47 | return pte; |
48 | } |
49 | |