| lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Re-map IO memory to kernel address space so that we can access it. |
| 3 | * This is needed for high PCI addresses that aren't mapped in the |
| 4 | * 640k-1MB IO memory area on PC's |
| 5 | * |
| 6 | * (C) Copyright 1995 1996 Linus Torvalds |
| 7 | */ |
| 8 | #include <linux/vmalloc.h> |
| 9 | #include <linux/mm.h> |
| 10 | #include <linux/sched.h> |
| 11 | #include <linux/io.h> |
| 12 | #include <linux/export.h> |
| 13 | #include <asm/cacheflush.h> |
| 14 | #include <asm/pgtable.h> |
| 15 | |
| 16 | static int ioremap_pte_range(pmd_t *pmd, unsigned long addr, |
| 17 | unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
| 18 | { |
| 19 | pte_t *pte; |
| 20 | u64 pfn; |
| 21 | |
| 22 | pfn = phys_addr >> PAGE_SHIFT; |
| 23 | pte = pte_alloc_kernel(pmd, addr); |
| 24 | if (!pte) |
| 25 | return -ENOMEM; |
| 26 | do { |
| 27 | /* BUG_ON(!pte_none(*pte)); */ |
| 28 | set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot)); |
| 29 | pfn++; |
| 30 | } while (pte++, addr += PAGE_SIZE, addr != end); |
| 31 | return 0; |
| 32 | } |
| 33 | |
| 34 | static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr, |
| 35 | unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
| 36 | { |
| 37 | pmd_t *pmd; |
| 38 | unsigned long next; |
| 39 | |
| 40 | phys_addr -= addr; |
| 41 | pmd = pmd_alloc(&init_mm, pud, addr); |
| 42 | if (!pmd) |
| 43 | return -ENOMEM; |
| 44 | do { |
| 45 | next = pmd_addr_end(addr, end); |
| 46 | if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot)) |
| 47 | return -ENOMEM; |
| 48 | } while (pmd++, addr = next, addr != end); |
| 49 | return 0; |
| 50 | } |
| 51 | |
| 52 | static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr, |
| 53 | unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
| 54 | { |
| 55 | pud_t *pud; |
| 56 | unsigned long next; |
| 57 | |
| 58 | phys_addr -= addr; |
| 59 | pud = pud_alloc(&init_mm, pgd, addr); |
| 60 | if (!pud) |
| 61 | return -ENOMEM; |
| 62 | do { |
| 63 | next = pud_addr_end(addr, end); |
| 64 | if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot)) |
| 65 | return -ENOMEM; |
| 66 | } while (pud++, addr = next, addr != end); |
| 67 | return 0; |
| 68 | } |
| 69 | |
| 70 | int ioremap_page_range(unsigned long addr, |
| 71 | unsigned long end, phys_addr_t phys_addr, pgprot_t prot) |
| 72 | { |
| 73 | pgd_t *pgd; |
| 74 | unsigned long start; |
| 75 | unsigned long next; |
| 76 | int err; |
| 77 | |
| 78 | BUG_ON(addr >= end); |
| 79 | |
| 80 | start = addr; |
| 81 | phys_addr -= addr; |
| 82 | pgd = pgd_offset_k(addr); |
| 83 | do { |
| 84 | next = pgd_addr_end(addr, end); |
| 85 | err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot); |
| 86 | if (err) |
| 87 | break; |
| 88 | } while (pgd++, addr = next, addr != end); |
| 89 | |
| 90 | flush_cache_vmap(start, end); |
| 91 | |
| 92 | return err; |
| 93 | } |
| 94 | EXPORT_SYMBOL_GPL(ioremap_page_range); |