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("%s: Failed to allocate %lu bytes align=0x%lx\n", 44 __func__, PAGE_SIZE, PAGE_SIZE); 45 } 46 47 return pte; 48 } 49