// SPDX-License-Identifier: GPL-2.0-only /* * arch/sh/mm/kmap.c * * Copyright (C) 1999, 2000, 2002 Niibe Yutaka * Copyright (C) 2002 - 2009 Paul Mundt */ #include <linux/mm.h> #include <linux/init.h> #include <linux/mutex.h> #include <linux/fs.h> #include <linux/highmem.h> #include <linux/module.h> #include <asm/mmu_context.h> #include <asm/cacheflush.h> #define kmap_get_fixmap_pte(vaddr) \ pte_offset_kernel(pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), (vaddr)) static pte_t *kmap_coherent_pte; void __init kmap_coherent_init(void) { unsigned long vaddr; /* cache the first coherent kmap pte */ vaddr = __fix_to_virt(FIX_CMAP_BEGIN); kmap_coherent_pte = kmap_get_fixmap_pte(vaddr); } void *kmap_coherent(struct page *page, unsigned long addr) { enum fixed_addresses idx; unsigned long vaddr; BUG_ON(!test_bit(PG_dcache_clean, &page->flags)); preempt_disable(); pagefault_disable(); idx = FIX_CMAP_END - (((addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1)) + (FIX_N_COLOURS * smp_processor_id())); vaddr = __fix_to_virt(idx); BUG_ON(!pte_none(*(kmap_coherent_pte - idx))); set_pte(kmap_coherent_pte - idx, mk_pte(page, PAGE_KERNEL)); return (void *)vaddr; } void kunmap_coherent(void *kvaddr) { if (kvaddr >= (void *)FIXADDR_START) { unsigned long vaddr = (unsigned long)kvaddr & PAGE_MASK; enum fixed_addresses idx = __virt_to_fix(vaddr); /* XXX.. Kill this later, here for sanity at the moment.. */ __flush_purge_region((void *)vaddr, PAGE_SIZE); pte_clear(&init_mm, vaddr, kmap_coherent_pte - idx); local_flush_tlb_one(get_asid(), vaddr); } pagefault_enable(); preempt_enable(); }