linux/arch/arm64/mm/flush.c
Will Deacon 4b3dc9679c arm64: force CONFIG_SMP=y and remove redundant #ifdefs
Nobody seems to be producing !SMP systems anymore, so this is just
becoming a source of kernel bugs, particularly if people want to use
coherent DMA with non-shared pages.

This patch forces CONFIG_SMP=y for arm64, removing a modest amount of
code in the process.

Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-07-27 11:08:40 +01:00

118 lines
3.1 KiB
C

/*
* Based on arch/arm/mm/flush.c
*
* Copyright (C) 1995-2002 Russell King
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <asm/cacheflush.h>
#include <asm/cachetype.h>
#include <asm/tlbflush.h>
#include "mm.h"
void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
if (vma->vm_flags & VM_EXEC)
__flush_icache_all();
}
static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
unsigned long uaddr, void *kaddr,
unsigned long len)
{
if (vma->vm_flags & VM_EXEC) {
unsigned long addr = (unsigned long)kaddr;
if (icache_is_aliasing()) {
__flush_dcache_area(kaddr, len);
__flush_icache_all();
} else {
flush_icache_range(addr, addr + len);
}
}
}
/*
* 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.
*
* Note that this code needs to run on the current CPU.
*/
void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long uaddr, void *dst, const void *src,
unsigned long len)
{
preempt_disable();
memcpy(dst, src, len);
flush_ptrace_access(vma, page, uaddr, dst, len);
preempt_enable();
}
void __sync_icache_dcache(pte_t pte, unsigned long addr)
{
struct page *page = pte_page(pte);
/* no flushing needed for anonymous pages */
if (!page_mapping(page))
return;
if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
__flush_dcache_area(page_address(page),
PAGE_SIZE << compound_order(page));
__flush_icache_all();
} else if (icache_is_aivivt()) {
__flush_icache_all();
}
}
/*
* 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_page(struct page *page)
{
if (test_bit(PG_dcache_clean, &page->flags))
clear_bit(PG_dcache_clean, &page->flags);
}
EXPORT_SYMBOL(flush_dcache_page);
/*
* Additional functions defined in assembly.
*/
EXPORT_SYMBOL(flush_icache_range);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#ifdef CONFIG_HAVE_RCU_TABLE_FREE
void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
pmd_t pmd = pmd_mksplitting(*pmdp);
VM_BUG_ON(address & ~PMD_MASK);
set_pmd_at(vma->vm_mm, address, pmdp, pmd);
/* dummy IPI to serialise against fast_gup */
kick_all_cpus_sync();
}
#endif /* CONFIG_HAVE_RCU_TABLE_FREE */
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */