diff options
Diffstat (limited to 'xenolinux-2.4.25-sparse/arch/xeno/mm/ioremap.c')
| -rw-r--r-- | xenolinux-2.4.25-sparse/arch/xeno/mm/ioremap.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/xenolinux-2.4.25-sparse/arch/xeno/mm/ioremap.c b/xenolinux-2.4.25-sparse/arch/xeno/mm/ioremap.c new file mode 100644 index 0000000000..e0e68216a3 --- /dev/null +++ b/xenolinux-2.4.25-sparse/arch/xeno/mm/ioremap.c @@ -0,0 +1,227 @@ +/* + * arch/xeno/mm/ioremap.c + * + * Re-map IO memory to kernel address space so that we can access it. + * + * (C) Copyright 1995 1996 Linus Torvalds + * + * Modifications for Xenolinux (c) 2003 Keir Fraser + */ + +#include <linux/slab.h> +#include <linux/mm.h> +#include <linux/mman.h> +#include <linux/vmalloc.h> +#include <asm/io.h> +#include <asm/pgalloc.h> +#include <asm/uaccess.h> +#include <asm/tlb.h> +#include <asm/mmu.h> + +#if defined(CONFIG_XENO_PRIV) + +#define direct_set_pte(_p, _v) queue_unchecked_mmu_update((_p), (_v).pte_low) +#define __direct_pte(x) ((pte_t) { (x) } ) +#define __direct_mk_pte(page_nr,pgprot) \ + __direct_pte(((page_nr) << PAGE_SHIFT) | pgprot_val(pgprot)) +#define direct_mk_pte_phys(physpage, pgprot) \ + __direct_mk_pte((physpage) >> PAGE_SHIFT, pgprot) + + +static inline void direct_remap_area_pte(pte_t *pte, + unsigned long address, + unsigned long size, + unsigned long machine_addr, + pgprot_t prot) +{ + unsigned long end; + + address &= ~PMD_MASK; + end = address + size; + if (end > PMD_SIZE) + end = PMD_SIZE; + if (address >= end) + BUG(); + do { + if (!pte_none(*pte)) { + printk("direct_remap_area_pte: page already exists\n"); + BUG(); + } + direct_set_pte(pte, pte_mkio(direct_mk_pte_phys(machine_addr, prot))); + address += PAGE_SIZE; + machine_addr += PAGE_SIZE; + pte++; + } while (address && (address < end)); +} + +static inline int direct_remap_area_pmd(struct mm_struct *mm, + pmd_t *pmd, + unsigned long address, + unsigned long size, + unsigned long machine_addr, + pgprot_t prot) +{ + unsigned long end; + + address &= ~PGDIR_MASK; + end = address + size; + if (end > PGDIR_SIZE) + end = PGDIR_SIZE; + machine_addr -= address; + if (address >= end) + BUG(); + do { + pte_t * pte = pte_alloc(mm, pmd, address); + if (!pte) + return -ENOMEM; + direct_remap_area_pte(pte, address, end - address, + address + machine_addr, prot); + address = (address + PMD_SIZE) & PMD_MASK; + pmd++; + } while (address && (address < end)); + return 0; +} + +int direct_remap_area_pages(struct mm_struct *mm, + unsigned long address, + unsigned long machine_addr, + unsigned long size, + pgprot_t prot) +{ + int error = 0; + pgd_t * dir; + unsigned long end = address + size; + + machine_addr -= address; + dir = pgd_offset(mm, address); + flush_cache_all(); + if (address >= end) + BUG(); + spin_lock(&mm->page_table_lock); + do { + pmd_t *pmd = pmd_alloc(mm, dir, address); + error = -ENOMEM; + if (!pmd) + break; + error = direct_remap_area_pmd(mm, pmd, address, end - address, + machine_addr + address, prot); + if (error) + break; + address = (address + PGDIR_SIZE) & PGDIR_MASK; + dir++; + } while (address && (address < end)); + spin_unlock(&mm->page_table_lock); + flush_tlb_all(); + return error; +} + +#endif /* CONFIG_XENO_PRIV */ + + +/* + * Remap an arbitrary machine address space into the kernel virtual + * address space. Needed when a privileged instance of Xenolinux wants + * to access space outside its world directly. + * + * NOTE! We need to allow non-page-aligned mappings too: we will obviously + * have to convert them into an offset in a page-aligned mapping, but the + * caller shouldn't need to know that small detail. + */ +void * __ioremap(unsigned long machine_addr, + unsigned long size, + unsigned long flags) +{ +#if defined(CONFIG_XENO_PRIV) + void * addr; + struct vm_struct * area; + unsigned long offset, last_addr; + pgprot_t prot; + + /* Only privileged Xenolinux can make unchecked pagetable updates. */ + if ( !(start_info.flags & SIF_PRIVILEGED) ) + return NULL; + + /* Don't allow wraparound or zero size */ + last_addr = machine_addr + size - 1; + if (!size || last_addr < machine_addr) + return NULL; + + /* Mappings have to be page-aligned */ + offset = machine_addr & ~PAGE_MASK; + machine_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr+1) - machine_addr; + + /* Ok, go for it */ + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + addr = area->addr; + prot = __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | + _PAGE_ACCESSED | flags); + if (direct_remap_area_pages(&init_mm, VMALLOC_VMADDR(addr), + machine_addr, size, prot)) { + vfree(addr); + return NULL; + } + return (void *) (offset + (char *)addr); +#else + return NULL; +#endif +} + +void iounmap(void *addr) +{ + vfree((void *)((unsigned long)addr & PAGE_MASK)); +} + +/* implementation of boot time ioremap for purpose of provising access +to the vga console for privileged domains. Unlike boot time ioremap on +other architectures, ours is permanent and not reclaimed when then vmalloc +infrastructure is started */ + +void __init *bt_ioremap(unsigned long machine_addr, unsigned long size) +{ + unsigned long offset, last_addr; + unsigned int nrpages; + enum fixed_addresses idx; + + /* Don't allow wraparound or zero size */ + last_addr = machine_addr + size - 1; + if (!size || last_addr < machine_addr) + return NULL; + + /* + * Mappings have to be page-aligned + */ + offset = machine_addr & ~PAGE_MASK; + machine_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr) - machine_addr; + + /* + * Mappings have to fit in the FIX_BTMAP area. + */ + nrpages = size >> PAGE_SHIFT; + if (nrpages > NR_FIX_BTMAPS) + return NULL; + + /* + * Ok, go for it.. + */ + idx = FIX_BTMAP_BEGIN; + while (nrpages > 0) { + __set_fixmap(idx, machine_addr, + __pgprot(__PAGE_KERNEL|_PAGE_IO)); + machine_addr += PAGE_SIZE; + --idx; + --nrpages; + } + + flush_tlb_all(); + + return (void*) (offset + fix_to_virt(FIX_BTMAP_BEGIN)); +} + + +#if 0 /* We don't support these functions. They shouldn't be required. */ +void __init bt_iounmap(void *addr, unsigned long size) {} +#endif |