From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- lib/ioremap.c | 147 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) create mode 100644 lib/ioremap.c (limited to 'lib/ioremap.c') diff --git a/lib/ioremap.c b/lib/ioremap.c new file mode 100644 index 000000000..86c8911b0 --- /dev/null +++ b/lib/ioremap.c @@ -0,0 +1,147 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +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_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_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)) { + 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(pgd_t *pgd, 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, pgd, 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)) { + 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; +} + +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; + + BUG_ON(addr >= end); + + start = addr; + phys_addr -= addr; + pgd = pgd_offset_k(addr); + do { + next = pgd_addr_end(addr, end); + err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot); + if (err) + break; + } while (pgd++, addr = next, addr != end); + + flush_cache_vmap(start, end); + + return err; +} +EXPORT_SYMBOL_GPL(ioremap_page_range); -- cgit v1.2.3-54-g00ecf