| // 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 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; |
| |
| phys_addr -= addr; |
| pmd = pmd_alloc(&init_mm, pud, addr); |
| if (!pmd) |
| return -ENOMEM; |
| do { |
| next = pmd_addr_end(addr, end); |
| |
| if (ioremap_pmd_enabled() && |
| ((next - addr) == PMD_SIZE) && |
| IS_ALIGNED(phys_addr + addr, PMD_SIZE) && |
| pmd_free_pte_page(pmd, addr)) { |
| if (pmd_set_huge(pmd, phys_addr + addr, prot)) |
| continue; |
| } |
| |
| if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot)) |
| return -ENOMEM; |
| } while (pmd++, addr = next, addr != end); |
| return 0; |
| } |
| |
| 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; |
| |
| phys_addr -= addr; |
| pud = pud_alloc(&init_mm, p4d, addr); |
| if (!pud) |
| return -ENOMEM; |
| do { |
| next = pud_addr_end(addr, end); |
| |
| if (ioremap_pud_enabled() && |
| ((next - addr) == PUD_SIZE) && |
| IS_ALIGNED(phys_addr + addr, PUD_SIZE) && |
| pud_free_pmd_page(pud, addr)) { |
| if (pud_set_huge(pud, phys_addr + addr, prot)) |
| continue; |
| } |
| |
| if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot)) |
| return -ENOMEM; |
| } while (pud++, addr = next, addr != end); |
| return 0; |
| } |
| |
| 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; |
| |
| phys_addr -= addr; |
| p4d = p4d_alloc(&init_mm, pgd, addr); |
| if (!p4d) |
| return -ENOMEM; |
| do { |
| next = p4d_addr_end(addr, end); |
| |
| if (ioremap_p4d_enabled() && |
| ((next - addr) == P4D_SIZE) && |
| IS_ALIGNED(phys_addr + addr, P4D_SIZE)) { |
| if (p4d_set_huge(p4d, phys_addr + addr, prot)) |
| continue; |
| } |
| |
| if (ioremap_pud_range(p4d, addr, next, phys_addr + addr, prot)) |
| return -ENOMEM; |
| } while (p4d++, 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; |
| phys_addr -= addr; |
| pgd = pgd_offset_k(addr); |
| do { |
| next = pgd_addr_end(addr, end); |
| err = ioremap_p4d_range(pgd, addr, next, phys_addr+addr, prot); |
| if (err) |
| break; |
| } while (pgd++, addr = next, addr != end); |
| |
| flush_cache_vmap(start, end); |
| |
| return err; |
| } |