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 static pte_t *kmap_coherent_pte; 18 19 void __init kmap_coherent_init(void) 20 { 21 unsigned long vaddr; 22 23 /* cache the first coherent kmap pte */ 24 vaddr = __fix_to_virt(FIX_CMAP_BEGIN); 25 kmap_coherent_pte = virt_to_kpte(vaddr); 26 } 27 28 void *kmap_coherent(struct page *page, unsigned long addr) 29 { 30 enum fixed_addresses idx; 31 unsigned long vaddr; 32 33 BUG_ON(!test_bit(PG_dcache_clean, &page->flags)); 34 35 preempt_disable(); 36 pagefault_disable(); 37 38 idx = FIX_CMAP_END - 39 (((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) + 40 (FIX_N_COLOURS * smp_processor_id())); 41 42 vaddr = __fix_to_virt(idx); 43 44 BUG_ON(!pte_none(*(kmap_coherent_pte - idx))); 45 set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL)); 46 47 return (void *)vaddr; 48 } 49 50 void kunmap_coherent(void *kvaddr) 51 { 52 if (kvaddr >= (void *)FIXADDR_START) { 53 unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK; 54 enum fixed_addresses idx = __virt_to_fix(vaddr); 55 56 /* XXX.. Kill this later, here for sanity at the moment.. */ 57 __flush_purge_region((void *)vaddr, PAGE_SIZE); 58 59 pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx); 60 local_flush_tlb_one(get_asid(), vaddr); 61 } 62 63 pagefault_enable(); 64 preempt_enable(); 65 } 66