From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-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! --- arch/i386/mm/boot_ioremap.c | 97 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 97 insertions(+) create mode 100644 arch/i386/mm/boot_ioremap.c (limited to 'arch/i386/mm/boot_ioremap.c') diff --git a/arch/i386/mm/boot_ioremap.c b/arch/i386/mm/boot_ioremap.c new file mode 100644 index 00000000000..523b30634e0 --- /dev/null +++ b/arch/i386/mm/boot_ioremap.c @@ -0,0 +1,97 @@ +/* + * arch/i386/mm/boot_ioremap.c + * + * Re-map functions for early boot-time before paging_init() when the + * boot-time pagetables are still in use + * + * Written by Dave Hansen + */ + + +/* + * We need to use the 2-level pagetable functions, but CONFIG_X86_PAE + * keeps that from happenning. If anyone has a better way, I'm listening. + * + * boot_pte_t is defined only if this all works correctly + */ + +#include +#undef CONFIG_X86_PAE +#include +#include +#include +#include +#include + +/* + * I'm cheating here. It is known that the two boot PTE pages are + * allocated next to each other. I'm pretending that they're just + * one big array. + */ + +#define BOOT_PTE_PTRS (PTRS_PER_PTE*2) +#define boot_pte_index(address) \ + (((address) >> PAGE_SHIFT) & (BOOT_PTE_PTRS - 1)) + +static inline boot_pte_t* boot_vaddr_to_pte(void *address) +{ + boot_pte_t* boot_pg = (boot_pte_t*)pg0; + return &boot_pg[boot_pte_index((unsigned long)address)]; +} + +/* + * This is only for a caller who is clever enough to page-align + * phys_addr and virtual_source, and who also has a preference + * about which virtual address from which to steal ptes + */ +static void __boot_ioremap(unsigned long phys_addr, unsigned long nrpages, + void* virtual_source) +{ + boot_pte_t* pte; + int i; + char *vaddr = virtual_source; + + pte = boot_vaddr_to_pte(virtual_source); + for (i=0; i < nrpages; i++, phys_addr += PAGE_SIZE, pte++) { + set_pte(pte, pfn_pte(phys_addr>>PAGE_SHIFT, PAGE_KERNEL)); + __flush_tlb_one(&vaddr[i*PAGE_SIZE]); + } +} + +/* the virtual space we're going to remap comes from this array */ +#define BOOT_IOREMAP_PAGES 4 +#define BOOT_IOREMAP_SIZE (BOOT_IOREMAP_PAGES*PAGE_SIZE) +static __initdata char boot_ioremap_space[BOOT_IOREMAP_SIZE] + __attribute__ ((aligned (PAGE_SIZE))); + +/* + * This only applies to things which need to ioremap before paging_init() + * bt_ioremap() and plain ioremap() are both useless at this point. + * + * When used, we're still using the boot-time pagetables, which only + * have 2 PTE pages mapping the first 8MB + * + * There is no unmap. The boot-time PTE pages aren't used after boot. + * If you really want the space back, just remap it yourself. + * boot_ioremap(&ioremap_space-PAGE_OFFSET, BOOT_IOREMAP_SIZE) + */ +__init void* boot_ioremap(unsigned long phys_addr, unsigned long size) +{ + unsigned long last_addr, offset; + unsigned int nrpages; + + last_addr = phys_addr + size - 1; + + /* page align the requested address */ + offset = phys_addr & ~PAGE_MASK; + phys_addr &= PAGE_MASK; + size = PAGE_ALIGN(last_addr) - phys_addr; + + nrpages = size >> PAGE_SHIFT; + if (nrpages > BOOT_IOREMAP_PAGES) + return NULL; + + __boot_ioremap(phys_addr, nrpages, boot_ioremap_space); + + return &boot_ioremap_space[offset]; +} -- cgit v1.2.3-70-g09d2