1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * arch/sh/mm/kmap.c 4 * 5 * Copyright (C) 1999, 2000, 2002 Niibe Yutaka 6 * Copyright (C) 2002 - 2009 Paul Mundt 7 */ 8 #include <linux/mm.h> 9 #include <linux/init.h> 10 #include <linux/mutex.h> 11 #include <linux/fs.h> 12 #include <linux/highmem.h> 13 #include <linux/module.h> 14 #include <asm/mmu_context.h> 15 #include <asm/cacheflush.h> 16 17 #define kmap_get_fixmap_pte(vaddr) \ 18 pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr)) 19 20 static pte_t *kmap_coherent_pte; 21 22 void __init kmap_coherent_init(void) 23 { 24 unsigned long vaddr; 25 26 /* cache the first coherent kmap pte */ 27 vaddr = __fix_to_virt(FIX_CMAP_BEGIN); 28 kmap_coherent_pte = kmap_get_fixmap_pte(vaddr); 29 } 30 31 void *kmap_coherent(struct page *page, unsigned long addr) 32 { 33 enum fixed_addresses idx; 34 unsigned long vaddr; 35 36 BUG_ON(!test_bit(PG_dcache_clean, &page->flags)); 37 38 preempt_disable(); 39 pagefault_disable(); 40 41 idx = FIX_CMAP_END - 42 (((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) + 43 (FIX_N_COLOURS * smp_processor_id())); 44 45 vaddr = __fix_to_virt(idx); 46 47 BUG_ON(!pte_none(*(kmap_coherent_pte - idx))); 48 set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL)); 49 50 return (void *)vaddr; 51 } 52 53 void kunmap_coherent(void *kvaddr) 54 { 55 if (kvaddr >= (void *)FIXADDR_START) { 56 unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK; 57 enum fixed_addresses idx = __virt_to_fix(vaddr); 58 59 /* XXX.. Kill this later, here for sanity at the moment.. */ 60 __flush_purge_region((void *)vaddr, PAGE_SIZE); 61 62 pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx); 63 local_flush_tlb_one(get_asid(), vaddr); 64 } 65 66 pagefault_enable(); 67 preempt_enable(); 68 } 69