1 /* 2 * arch/sh/mm/kmap.c 3 * 4 * Copyright (C) 1999, 2000, 2002 Niibe Yutaka 5 * Copyright (C) 2002 - 2009 Paul Mundt 6 * 7 * Released under the terms of the GNU GPL v2.0. 8 */ 9 #include <linux/mm.h> 10 #include <linux/init.h> 11 #include <linux/mutex.h> 12 #include <linux/fs.h> 13 #include <linux/highmem.h> 14 #include <linux/module.h> 15 #include <asm/mmu_context.h> 16 #include <asm/cacheflush.h> 17 18 #define kmap_get_fixmap_pte(vaddr) \ 19 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr)) 20 21 static pte_t *kmap_coherent_pte; 22 23 void __init kmap_coherent_init(void) 24 { 25 unsigned long vaddr; 26 27 /* cache the first coherent kmap pte */ 28 vaddr = __fix_to_virt(FIX_CMAP_BEGIN); 29 kmap_coherent_pte = kmap_get_fixmap_pte(vaddr); 30 } 31 32 void *kmap_coherent(struct page *page, unsigned long addr) 33 { 34 enum fixed_addresses idx; 35 unsigned long vaddr; 36 37 BUG_ON(!test_bit(PG_dcache_clean, &page->flags)); 38 39 preempt_disable(); 40 pagefault_disable(); 41 42 idx = FIX_CMAP_END - 43 (((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) + 44 (FIX_N_COLOURS * smp_processor_id())); 45 46 vaddr = __fix_to_virt(idx); 47 48 BUG_ON(!pte_none(*(kmap_coherent_pte - idx))); 49 set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL)); 50 51 return (void *)vaddr; 52 } 53 54 void kunmap_coherent(void *kvaddr) 55 { 56 if (kvaddr >= (void *)FIXADDR_START) { 57 unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK; 58 enum fixed_addresses idx = __virt_to_fix(vaddr); 59 60 /* XXX.. Kill this later, here for sanity at the moment.. */ 61 __flush_purge_region((void *)vaddr, PAGE_SIZE); 62 63 pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx); 64 local_flush_tlb_one(get_asid(), vaddr); 65 } 66 67 pagefault_enable(); 68 preempt_enable(); 69 } 70