kmap.c (1520B)
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 17static pte_t *kmap_coherent_pte; 18 19void __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 28void *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 50void 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}