// SPDX-License-Identifier: GPL-2.0 /* * Re-map IO memory to kernel address space so that we can access it. * This is needed for high PCI addresses that aren't mapped in the * 640k-1MB IO memory area on PC's * * (C) Copyright 1995 1996 Linus Torvalds */ #include <linux/vmalloc.h> #include <linux/mm.h> #include <linux/sched.h> #include <linux/io.h> #include <linux/export.h> #include <asm/cacheflush.h> #include <asm/pgtable.h> #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP static int __read_mostly ioremap_p4d_capable; static int __read_mostly ioremap_pud_capable; static int __read_mostly ioremap_pmd_capable; static int __read_mostly ioremap_huge_disabled; static int __init set_nohugeiomap(char *str) { ioremap_huge_disabled = 1; return 0; } early_param("nohugeiomap", set_nohugeiomap); void __init ioremap_huge_init(void) { if (!ioremap_huge_disabled) { if (arch_ioremap_pud_supported()) ioremap_pud_capable = 1; if (arch_ioremap_pmd_supported()) ioremap_pmd_capable = 1; } } static inline int ioremap_p4d_enabled(void) { return ioremap_p4d_capable; } static inline int ioremap_pud_enabled(void) { return ioremap_pud_capable; } static inline int ioremap_pmd_enabled(void) { return ioremap_pmd_capable; } #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */ static inline int ioremap_p4d_enabled(void) { return 0; } static inline int ioremap_pud_enabled(void) { return 0; } static inline int ioremap_pmd_enabled(void) { return 0; } #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ static int ioremap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { pte_t *pte; u64 pfn; pfn = phys_addr >> PAGE_SHIFT; pte = pte_alloc_kernel(pmd, addr); if (!pte) return -ENOMEM; do { BUG_ON(!pte_none(*pte)); set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot)); pfn++; } while (pte++, addr += PAGE_SIZE, addr != end); return 0; } static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { if (!ioremap_pmd_enabled()) return 0; if ((end - addr) != PMD_SIZE) return 0; if (!IS_ALIGNED(phys_addr, PMD_SIZE)) return 0; if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr)) return 0; return pmd_set_huge(pmd, phys_addr, prot); } static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { pmd_t *pmd; unsigned long next; pmd = pmd_alloc(&init_mm, pud, addr); if (!pmd) return -ENOMEM; do { next = pmd_addr_end(addr, end); if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) continue; if (ioremap_pte_range(pmd, addr, next, phys_addr, prot)) return -ENOMEM; } while (pmd++, phys_addr += (next - addr), addr = next, addr != end); return 0; } static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { if (!ioremap_pud_enabled()) return 0; if ((end - addr) != PUD_SIZE) return 0; if (!IS_ALIGNED(phys_addr, PUD_SIZE)) return 0; if (pud_present(*pud) && !pud_free_pmd_page(pud, addr)) return 0; return pud_set_huge(pud, phys_addr, prot); } static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { pud_t *pud; unsigned long next; pud = pud_alloc(&init_mm, p4d, addr); if (!pud) return -ENOMEM; do { next = pud_addr_end(addr, end); if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot)) continue; if (ioremap_pmd_range(pud, addr, next, phys_addr, prot)) return -ENOMEM; } while (pud++, phys_addr += (next - addr), addr = next, addr != end); return 0; } static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { if (!ioremap_p4d_enabled()) return 0; if ((end - addr) != P4D_SIZE) return 0; if (!IS_ALIGNED(phys_addr, P4D_SIZE)) return 0; if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr)) return 0; return p4d_set_huge(p4d, phys_addr, prot); } static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { p4d_t *p4d; unsigned long next; p4d = p4d_alloc(&init_mm, pgd, addr); if (!p4d) return -ENOMEM; do { next = p4d_addr_end(addr, end); if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) continue; if (ioremap_pud_range(p4d, addr, next, phys_addr, prot)) return -ENOMEM; } while (p4d++, phys_addr += (next - addr), addr = next, addr != end); return 0; } int ioremap_page_range(unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { pgd_t *pgd; unsigned long start; unsigned long next; int err; might_sleep(); BUG_ON(addr >= end); start = addr; pgd = pgd_offset_k(addr); do { next = pgd_addr_end(addr, end); err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot); if (err) break; } while (pgd++, phys_addr += (next - addr), addr = next, addr != end); flush_cache_vmap(start, end); return err; }