1 // SPDX-License-Identifier: GPL-2.0 <<
2 /* 1 /*
3 * Copyright (C) 2020-2022 Loongson Technology !! 2 * This file is subject to the terms and conditions of the GNU General Public
>> 3 * License. See the file "COPYING" in the main directory of this archive
>> 4 * for more details.
>> 5 *
>> 6 * (C) Copyright 1995 1996 Linus Torvalds
>> 7 * (C) Copyright 2001, 2002 Ralf Baechle
4 */ 8 */
>> 9 #include <linux/export.h>
>> 10 #include <asm/addrspace.h>
>> 11 #include <asm/byteorder.h>
>> 12 #include <linux/ioport.h>
>> 13 #include <linux/sched.h>
>> 14 #include <linux/slab.h>
>> 15 #include <linux/vmalloc.h>
>> 16 #include <linux/mm_types.h>
>> 17 #include <linux/io.h>
>> 18 #include <asm/cacheflush.h>
>> 19 #include <asm/tlbflush.h>
>> 20 #include <ioremap.h>
5 21
6 #include <asm/io.h> !! 22 #define IS_LOW512(addr) (!((phys_addr_t)(addr) & (phys_addr_t) ~0x1fffffffULL))
7 #include <asm-generic/early_ioremap.h> !! 23 #define IS_KSEG1(addr) (((unsigned long)(addr) & ~0x1fffffffUL) == CKSEG1)
8 24
9 void __init __iomem *early_ioremap(u64 phys_ad !! 25 static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
>> 26 void *arg)
10 { 27 {
11 return ((void __iomem *)TO_CACHE(phys_ !! 28 unsigned long i;
12 } <<
13 29
14 void __init early_iounmap(void __iomem *addr, !! 30 for (i = 0; i < nr_pages; i++) {
15 { !! 31 if (pfn_valid(start_pfn + i) &&
>> 32 !PageReserved(pfn_to_page(start_pfn + i)))
>> 33 return 1;
>> 34 }
16 35
>> 36 return 0;
17 } 37 }
18 38
19 void *early_memremap_ro(resource_size_t phys_a !! 39 /*
>> 40 * ioremap_prot - map bus memory into CPU space
>> 41 * @phys_addr: bus address of the memory
>> 42 * @size: size of the resource to map
>> 43 *
>> 44 * ioremap_prot gives the caller control over cache coherency attributes (CCA)
>> 45 */
>> 46 void __iomem *ioremap_prot(phys_addr_t phys_addr, unsigned long size,
>> 47 unsigned long prot_val)
20 { 48 {
21 return early_memremap(phys_addr, size) !! 49 unsigned long flags = prot_val & _CACHE_MASK;
>> 50 unsigned long offset, pfn, last_pfn;
>> 51 struct vm_struct *area;
>> 52 phys_addr_t last_addr;
>> 53 unsigned long vaddr;
>> 54 void __iomem *cpu_addr;
>> 55
>> 56 cpu_addr = plat_ioremap(phys_addr, size, flags);
>> 57 if (cpu_addr)
>> 58 return cpu_addr;
>> 59
>> 60 phys_addr = fixup_bigphys_addr(phys_addr, size);
>> 61
>> 62 /* Don't allow wraparound or zero size */
>> 63 last_addr = phys_addr + size - 1;
>> 64 if (!size || last_addr < phys_addr)
>> 65 return NULL;
>> 66
>> 67 /*
>> 68 * Map uncached objects in the low 512mb of address space using KSEG1,
>> 69 * otherwise map using page tables.
>> 70 */
>> 71 if (IS_LOW512(phys_addr) && IS_LOW512(last_addr) &&
>> 72 flags == _CACHE_UNCACHED)
>> 73 return (void __iomem *) CKSEG1ADDR(phys_addr);
>> 74
>> 75 /* Early remaps should use the unmapped regions til' VM is available */
>> 76 if (WARN_ON_ONCE(!slab_is_available()))
>> 77 return NULL;
>> 78
>> 79 /*
>> 80 * Don't allow anybody to remap RAM that may be allocated by the page
>> 81 * allocator, since that could lead to races & data clobbering.
>> 82 */
>> 83 pfn = PFN_DOWN(phys_addr);
>> 84 last_pfn = PFN_DOWN(last_addr);
>> 85 if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
>> 86 __ioremap_check_ram) == 1) {
>> 87 WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
>> 88 &phys_addr, &last_addr);
>> 89 return NULL;
>> 90 }
>> 91
>> 92 /*
>> 93 * Mappings have to be page-aligned
>> 94 */
>> 95 offset = phys_addr & ~PAGE_MASK;
>> 96 phys_addr &= PAGE_MASK;
>> 97 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
>> 98
>> 99 /*
>> 100 * Ok, go for it..
>> 101 */
>> 102 area = get_vm_area(size, VM_IOREMAP);
>> 103 if (!area)
>> 104 return NULL;
>> 105 vaddr = (unsigned long)area->addr;
>> 106
>> 107 flags |= _PAGE_GLOBAL | _PAGE_PRESENT | __READABLE | __WRITEABLE;
>> 108 if (ioremap_page_range(vaddr, vaddr + size, phys_addr,
>> 109 __pgprot(flags))) {
>> 110 free_vm_area(area);
>> 111 return NULL;
>> 112 }
>> 113
>> 114 return (void __iomem *)(vaddr + offset);
22 } 115 }
>> 116 EXPORT_SYMBOL(ioremap_prot);
23 117
24 void *early_memremap_prot(resource_size_t phys !! 118 void iounmap(const volatile void __iomem *addr)
25 unsigned long prot_val) <<
26 { 119 {
27 return early_memremap(phys_addr, size) !! 120 if (!plat_iounmap(addr) && !IS_KSEG1(addr))
>> 121 vunmap((void *)((unsigned long)addr & PAGE_MASK));
28 } 122 }
>> 123 EXPORT_SYMBOL(iounmap);
29 124
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