diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/s390/mm/ioremap.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/s390/mm/ioremap.c')
-rw-r--r-- | arch/s390/mm/ioremap.c | 138 |
1 files changed, 138 insertions, 0 deletions
diff --git a/arch/s390/mm/ioremap.c b/arch/s390/mm/ioremap.c new file mode 100644 index 000000000000..c6c39d868bc8 --- /dev/null +++ b/arch/s390/mm/ioremap.c @@ -0,0 +1,138 @@ +/* + * arch/s390/mm/ioremap.c + * + * S390 version + * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation + * Author(s): Hartmut Penner (hp@de.ibm.com) + * + * Derived from "arch/i386/mm/extable.c" + * (C) Copyright 1995 1996 Linus Torvalds + * + * 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 + */ + +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <asm/io.h> +#include <asm/pgalloc.h> +#include <asm/cacheflush.h> +#include <asm/tlbflush.h> + +static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size, + unsigned long phys_addr, unsigned long flags) +{ + unsigned long end; + unsigned long pfn; + + address &= ~PMD_MASK; + end = address + size; + if (end > PMD_SIZE) + end = PMD_SIZE; + if (address >= end) + BUG(); + pfn = phys_addr >> PAGE_SHIFT; + do { + if (!pte_none(*pte)) { + printk("remap_area_pte: page already exists\n"); + BUG(); + } + set_pte(pte, pfn_pte(pfn, __pgprot(flags))); + address += PAGE_SIZE; + pfn++; + pte++; + } while (address && (address < end)); +} + +static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size, + unsigned long phys_addr, unsigned long flags) +{ + unsigned long end; + + address &= ~PGDIR_MASK; + end = address + size; + if (end > PGDIR_SIZE) + end = PGDIR_SIZE; + phys_addr -= address; + if (address >= end) + BUG(); + do { + pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address); + if (!pte) + return -ENOMEM; + remap_area_pte(pte, address, end - address, address + phys_addr, flags); + address = (address + PMD_SIZE) & PMD_MASK; + pmd++; + } while (address && (address < end)); + return 0; +} + +static int remap_area_pages(unsigned long address, unsigned long phys_addr, + unsigned long size, unsigned long flags) +{ + int error; + pgd_t * dir; + unsigned long end = address + size; + + phys_addr -= address; + dir = pgd_offset(&init_mm, address); + flush_cache_all(); + if (address >= end) + BUG(); + spin_lock(&init_mm.page_table_lock); + do { + pmd_t *pmd; + pmd = pmd_alloc(&init_mm, dir, address); + error = -ENOMEM; + if (!pmd) + break; + if (remap_area_pmd(pmd, address, end - address, + phys_addr + address, flags)) + break; + error = 0; + address = (address + PGDIR_SIZE) & PGDIR_MASK; + dir++; + } while (address && (address < end)); + spin_unlock(&init_mm.page_table_lock); + flush_tlb_all(); + return 0; +} + +/* + * Generic mapping function (not visible outside): + */ + +/* + * Remap an arbitrary physical address space into the kernel virtual + * address space. Needed when the kernel wants to access high addresses + * directly. + */ +void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags) +{ + void * addr; + struct vm_struct * area; + + if (phys_addr < virt_to_phys(high_memory)) + return phys_to_virt(phys_addr); + if (phys_addr & ~PAGE_MASK) + return NULL; + size = PAGE_ALIGN(size); + if (!size || size > phys_addr + size) + return NULL; + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + addr = area->addr; + if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) { + vfree(addr); + return NULL; + } + return addr; +} + +void iounmap(void *addr) +{ + if (addr > high_memory) + vfree(addr); +} |