1da177e4c3
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!
146 lines
3.5 KiB
C
146 lines
3.5 KiB
C
/*
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* arch/cris/mm/ioremap.c
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*
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* Re-map IO memory to kernel address space so that we can access it.
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* Needed for memory-mapped I/O devices mapped outside our normal DRAM
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* window (that is, all memory-mapped I/O devices).
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*
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* (C) Copyright 1995 1996 Linus Torvalds
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* CRIS-port by Axis Communications AB
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*/
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#include <linux/vmalloc.h>
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#include <asm/io.h>
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#include <asm/pgalloc.h>
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#include <asm/cacheflush.h>
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#include <asm/tlbflush.h>
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extern inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
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unsigned long phys_addr, unsigned long flags)
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{
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unsigned long end;
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address &= ~PMD_MASK;
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end = address + size;
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if (end > PMD_SIZE)
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end = PMD_SIZE;
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if (address >= end)
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BUG();
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do {
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if (!pte_none(*pte)) {
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printk("remap_area_pte: page already exists\n");
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BUG();
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}
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set_pte(pte, mk_pte_phys(phys_addr, __pgprot(_PAGE_PRESENT | __READABLE |
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__WRITEABLE | _PAGE_GLOBAL |
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_PAGE_KERNEL | flags)));
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address += PAGE_SIZE;
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phys_addr += PAGE_SIZE;
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pte++;
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} while (address && (address < end));
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}
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static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
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unsigned long phys_addr, unsigned long flags)
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{
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unsigned long end;
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address &= ~PGDIR_MASK;
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end = address + size;
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if (end > PGDIR_SIZE)
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end = PGDIR_SIZE;
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phys_addr -= address;
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if (address >= end)
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BUG();
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do {
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pte_t * pte = pte_alloc_kernel(&init_mm, pmd, address);
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if (!pte)
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return -ENOMEM;
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remap_area_pte(pte, address, end - address, address + phys_addr, flags);
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address = (address + PMD_SIZE) & PMD_MASK;
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pmd++;
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} while (address && (address < end));
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return 0;
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}
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static int remap_area_pages(unsigned long address, unsigned long phys_addr,
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unsigned long size, unsigned long flags)
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{
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int error;
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pgd_t * dir;
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unsigned long end = address + size;
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phys_addr -= address;
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dir = pgd_offset(&init_mm, address);
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flush_cache_all();
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if (address >= end)
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BUG();
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spin_lock(&init_mm.page_table_lock);
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do {
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pmd_t *pmd;
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pmd = pmd_alloc(&init_mm, dir, address);
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error = -ENOMEM;
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if (!pmd)
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break;
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if (remap_area_pmd(pmd, address, end - address,
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phys_addr + address, flags))
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break;
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error = 0;
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address = (address + PGDIR_SIZE) & PGDIR_MASK;
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dir++;
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} while (address && (address < end));
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spin_unlock(&init_mm.page_table_lock);
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flush_tlb_all();
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return error;
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}
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/*
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* Generic mapping function (not visible outside):
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*/
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/*
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* Remap an arbitrary physical address space into the kernel virtual
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* address space. Needed when the kernel wants to access high addresses
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* directly.
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*
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* NOTE! We need to allow non-page-aligned mappings too: we will obviously
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* have to convert them into an offset in a page-aligned mapping, but the
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* caller shouldn't need to know that small detail.
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*/
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void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
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{
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void * addr;
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struct vm_struct * area;
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unsigned long offset, last_addr;
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/* Don't allow wraparound or zero size */
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last_addr = phys_addr + size - 1;
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if (!size || last_addr < phys_addr)
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return NULL;
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/*
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* Mappings have to be page-aligned
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*/
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offset = phys_addr & ~PAGE_MASK;
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phys_addr &= PAGE_MASK;
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size = PAGE_ALIGN(last_addr+1) - phys_addr;
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/*
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* Ok, go for it..
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*/
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area = get_vm_area(size, VM_IOREMAP);
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if (!area)
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return NULL;
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addr = area->addr;
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if (remap_area_pages((unsigned long) addr, phys_addr, size, flags)) {
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vfree(addr);
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return NULL;
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}
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return (void *) (offset + (char *)addr);
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}
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void iounmap(void *addr)
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{
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if (addr > high_memory)
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return vfree((void *) (PAGE_MASK & (unsigned long) addr));
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}
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