flush.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Based on arch/arm/mm/flush.c
 *
 * Copyright (C) 1995-2002 Russell King
 * Copyright (C) 2012 ARM Ltd.
 */

#include <linux/export.h>
#include <linux/mm.h>
#include <linux/libnvdimm.h>
#include <linux/pagemap.h>

#include <asm/cacheflush.h>
#include <asm/cache.h>
#include <asm/tlbflush.h>

void sync_icache_aliases(unsigned long start, unsigned long end)
{
	if (icache_is_aliasing()) {
		dcache_clean_pou(start, end);
		icache_inval_all_pou();
	} else {
		/*
		 * Don't issue kick_all_cpus_sync() after I-cache invalidation
		 * for user mappings.
		 */
		caches_clean_inval_pou(start, end);
	}
}

static void flush_ptrace_access(struct vm_area_struct *vma, unsigned long start,
				unsigned long end)
{
	if (vma->vm_flags & VM_EXEC)
		sync_icache_aliases(start, end);
}

/*
 * Copy user data from/to a page which is mapped into a different processes
 * address space.  Really, we want to allow our "user space" model to handle
 * this.
 */
void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
		       unsigned long uaddr, void *dst, const void *src,
		       unsigned long len)
{
	memcpy(dst, src, len);
	flush_ptrace_access(vma, (unsigned long)dst, (unsigned long)dst + len);
}

void __sync_icache_dcache(pte_t pte)
{
	struct folio *folio = page_folio(pte_page(pte));

	if (!test_bit(PG_dcache_clean, &folio->flags)) {
		sync_icache_aliases((unsigned long)folio_address(folio),
				    (unsigned long)folio_address(folio) +
					    folio_size(folio));
		set_bit(PG_dcache_clean, &folio->flags);
	}
}
EXPORT_SYMBOL_GPL(__sync_icache_dcache);

/*
 * This function is called when a page has been modified by the kernel. Mark
 * it as dirty for later flushing when mapped in user space (if executable,
 * see __sync_icache_dcache).
 */
void flush_dcache_folio(struct folio *folio)
{
	if (test_bit(PG_dcache_clean, &folio->flags))
		clear_bit(PG_dcache_clean, &folio->flags);
}
EXPORT_SYMBOL(flush_dcache_folio);

void flush_dcache_page(struct page *page)
{
	flush_dcache_folio(page_folio(page));
}
EXPORT_SYMBOL(flush_dcache_page);

/*
 * Additional functions defined in assembly.
 */
EXPORT_SYMBOL(caches_clean_inval_pou);

#ifdef CONFIG_ARCH_HAS_PMEM_API
void arch_wb_cache_pmem(void *addr, size_t size)
{
	/* Ensure order against any prior non-cacheable writes */
	dmb(osh);
	dcache_clean_pop((unsigned long)addr, (unsigned long)addr + size);
}
EXPORT_SYMBOL_GPL(arch_wb_cache_pmem);

void arch_invalidate_pmem(void *addr, size_t size)
{
	dcache_inval_poc((unsigned long)addr, (unsigned long)addr + size);
}
EXPORT_SYMBOL_GPL(arch_invalidate_pmem);
#endif