linux/arch/sh/mm/cache.c
Stuart Menefy a25bbe1222 sh: Flush executable pages in copy_user_highpage
This resolves a problem seen when using the Android dynamic linker.
Sometimes the dynamic linker would seg-fault at start up and this
was eventually traced to the handling of a COW fault for a page which
was being modified by the linker. If there was no cache aliasing between
the kernel and the user page, the page was not flushed, leaving the
newly copied data in the D-cache. However when executing instructions
from that page, the I-cache is filled directly from external memory,
rather than the D-cache, and causing garbage to be executed.

Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2011-02-15 16:24:31 +09:00

356 lines
9.3 KiB
C

/*
* arch/sh/mm/cache.c
*
* Copyright (C) 1999, 2000, 2002 Niibe Yutaka
* Copyright (C) 2002 - 2010 Paul Mundt
*
* Released under the terms of the GNU GPL v2.0.
*/
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/highmem.h>
#include <linux/module.h>
#include <asm/mmu_context.h>
#include <asm/cacheflush.h>
void (*local_flush_cache_all)(void *args) = cache_noop;
void (*local_flush_cache_mm)(void *args) = cache_noop;
void (*local_flush_cache_dup_mm)(void *args) = cache_noop;
void (*local_flush_cache_page)(void *args) = cache_noop;
void (*local_flush_cache_range)(void *args) = cache_noop;
void (*local_flush_dcache_page)(void *args) = cache_noop;
void (*local_flush_icache_range)(void *args) = cache_noop;
void (*local_flush_icache_page)(void *args) = cache_noop;
void (*local_flush_cache_sigtramp)(void *args) = cache_noop;
void (*__flush_wback_region)(void *start, int size);
EXPORT_SYMBOL(__flush_wback_region);
void (*__flush_purge_region)(void *start, int size);
EXPORT_SYMBOL(__flush_purge_region);
void (*__flush_invalidate_region)(void *start, int size);
EXPORT_SYMBOL(__flush_invalidate_region);
static inline void noop__flush_region(void *start, int size)
{
}
static inline void cacheop_on_each_cpu(void (*func) (void *info), void *info,
int wait)
{
preempt_disable();
/*
* It's possible that this gets called early on when IRQs are
* still disabled due to ioremapping by the boot CPU, so don't
* even attempt IPIs unless there are other CPUs online.
*/
if (num_online_cpus() > 1)
smp_call_function(func, info, wait);
func(info);
preempt_enable();
}
void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long vaddr, void *dst, const void *src,
unsigned long len)
{
if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
test_bit(PG_dcache_clean, &page->flags)) {
void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
memcpy(vto, src, len);
kunmap_coherent(vto);
} else {
memcpy(dst, src, len);
if (boot_cpu_data.dcache.n_aliases)
clear_bit(PG_dcache_clean, &page->flags);
}
if (vma->vm_flags & VM_EXEC)
flush_cache_page(vma, vaddr, page_to_pfn(page));
}
void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long vaddr, void *dst, const void *src,
unsigned long len)
{
if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
test_bit(PG_dcache_clean, &page->flags)) {
void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
memcpy(dst, vfrom, len);
kunmap_coherent(vfrom);
} else {
memcpy(dst, src, len);
if (boot_cpu_data.dcache.n_aliases)
clear_bit(PG_dcache_clean, &page->flags);
}
}
void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma)
{
void *vfrom, *vto;
vto = kmap_atomic(to, KM_USER1);
if (boot_cpu_data.dcache.n_aliases && page_mapped(from) &&
test_bit(PG_dcache_clean, &from->flags)) {
vfrom = kmap_coherent(from, vaddr);
copy_page(vto, vfrom);
kunmap_coherent(vfrom);
} else {
vfrom = kmap_atomic(from, KM_USER0);
copy_page(vto, vfrom);
kunmap_atomic(vfrom, KM_USER0);
}
if (pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK) ||
(vma->vm_flags & VM_EXEC))
__flush_purge_region(vto, PAGE_SIZE);
kunmap_atomic(vto, KM_USER1);
/* Make sure this page is cleared on other CPU's too before using it */
smp_wmb();
}
EXPORT_SYMBOL(copy_user_highpage);
void clear_user_highpage(struct page *page, unsigned long vaddr)
{
void *kaddr = kmap_atomic(page, KM_USER0);
clear_page(kaddr);
if (pages_do_alias((unsigned long)kaddr, vaddr & PAGE_MASK))
__flush_purge_region(kaddr, PAGE_SIZE);
kunmap_atomic(kaddr, KM_USER0);
}
EXPORT_SYMBOL(clear_user_highpage);
void __update_cache(struct vm_area_struct *vma,
unsigned long address, pte_t pte)
{
struct page *page;
unsigned long pfn = pte_pfn(pte);
if (!boot_cpu_data.dcache.n_aliases)
return;
page = pfn_to_page(pfn);
if (pfn_valid(pfn)) {
int dirty = !test_and_set_bit(PG_dcache_clean, &page->flags);
if (dirty)
__flush_purge_region(page_address(page), PAGE_SIZE);
}
}
void __flush_anon_page(struct page *page, unsigned long vmaddr)
{
unsigned long addr = (unsigned long) page_address(page);
if (pages_do_alias(addr, vmaddr)) {
if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
test_bit(PG_dcache_clean, &page->flags)) {
void *kaddr;
kaddr = kmap_coherent(page, vmaddr);
/* XXX.. For now kunmap_coherent() does a purge */
/* __flush_purge_region((void *)kaddr, PAGE_SIZE); */
kunmap_coherent(kaddr);
} else
__flush_purge_region((void *)addr, PAGE_SIZE);
}
}
void flush_cache_all(void)
{
cacheop_on_each_cpu(local_flush_cache_all, NULL, 1);
}
EXPORT_SYMBOL(flush_cache_all);
void flush_cache_mm(struct mm_struct *mm)
{
if (boot_cpu_data.dcache.n_aliases == 0)
return;
cacheop_on_each_cpu(local_flush_cache_mm, mm, 1);
}
void flush_cache_dup_mm(struct mm_struct *mm)
{
if (boot_cpu_data.dcache.n_aliases == 0)
return;
cacheop_on_each_cpu(local_flush_cache_dup_mm, mm, 1);
}
void flush_cache_page(struct vm_area_struct *vma, unsigned long addr,
unsigned long pfn)
{
struct flusher_data data;
data.vma = vma;
data.addr1 = addr;
data.addr2 = pfn;
cacheop_on_each_cpu(local_flush_cache_page, (void *)&data, 1);
}
void flush_cache_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end)
{
struct flusher_data data;
data.vma = vma;
data.addr1 = start;
data.addr2 = end;
cacheop_on_each_cpu(local_flush_cache_range, (void *)&data, 1);
}
EXPORT_SYMBOL(flush_cache_range);
void flush_dcache_page(struct page *page)
{
cacheop_on_each_cpu(local_flush_dcache_page, page, 1);
}
EXPORT_SYMBOL(flush_dcache_page);
void flush_icache_range(unsigned long start, unsigned long end)
{
struct flusher_data data;
data.vma = NULL;
data.addr1 = start;
data.addr2 = end;
cacheop_on_each_cpu(local_flush_icache_range, (void *)&data, 1);
}
void flush_icache_page(struct vm_area_struct *vma, struct page *page)
{
/* Nothing uses the VMA, so just pass the struct page along */
cacheop_on_each_cpu(local_flush_icache_page, page, 1);
}
void flush_cache_sigtramp(unsigned long address)
{
cacheop_on_each_cpu(local_flush_cache_sigtramp, (void *)address, 1);
}
static void compute_alias(struct cache_info *c)
{
c->alias_mask = ((c->sets - 1) << c->entry_shift) & ~(PAGE_SIZE - 1);
c->n_aliases = c->alias_mask ? (c->alias_mask >> PAGE_SHIFT) + 1 : 0;
}
static void __init emit_cache_params(void)
{
printk(KERN_NOTICE "I-cache : n_ways=%d n_sets=%d way_incr=%d\n",
boot_cpu_data.icache.ways,
boot_cpu_data.icache.sets,
boot_cpu_data.icache.way_incr);
printk(KERN_NOTICE "I-cache : entry_mask=0x%08x alias_mask=0x%08x n_aliases=%d\n",
boot_cpu_data.icache.entry_mask,
boot_cpu_data.icache.alias_mask,
boot_cpu_data.icache.n_aliases);
printk(KERN_NOTICE "D-cache : n_ways=%d n_sets=%d way_incr=%d\n",
boot_cpu_data.dcache.ways,
boot_cpu_data.dcache.sets,
boot_cpu_data.dcache.way_incr);
printk(KERN_NOTICE "D-cache : entry_mask=0x%08x alias_mask=0x%08x n_aliases=%d\n",
boot_cpu_data.dcache.entry_mask,
boot_cpu_data.dcache.alias_mask,
boot_cpu_data.dcache.n_aliases);
/*
* Emit Secondary Cache parameters if the CPU has a probed L2.
*/
if (boot_cpu_data.flags & CPU_HAS_L2_CACHE) {
printk(KERN_NOTICE "S-cache : n_ways=%d n_sets=%d way_incr=%d\n",
boot_cpu_data.scache.ways,
boot_cpu_data.scache.sets,
boot_cpu_data.scache.way_incr);
printk(KERN_NOTICE "S-cache : entry_mask=0x%08x alias_mask=0x%08x n_aliases=%d\n",
boot_cpu_data.scache.entry_mask,
boot_cpu_data.scache.alias_mask,
boot_cpu_data.scache.n_aliases);
}
}
void __init cpu_cache_init(void)
{
unsigned int cache_disabled = 0;
#ifdef CCR
cache_disabled = !(__raw_readl(CCR) & CCR_CACHE_ENABLE);
#endif
compute_alias(&boot_cpu_data.icache);
compute_alias(&boot_cpu_data.dcache);
compute_alias(&boot_cpu_data.scache);
__flush_wback_region = noop__flush_region;
__flush_purge_region = noop__flush_region;
__flush_invalidate_region = noop__flush_region;
/*
* No flushing is necessary in the disabled cache case so we can
* just keep the noop functions in local_flush_..() and __flush_..()
*/
if (unlikely(cache_disabled))
goto skip;
if (boot_cpu_data.family == CPU_FAMILY_SH2) {
extern void __weak sh2_cache_init(void);
sh2_cache_init();
}
if (boot_cpu_data.family == CPU_FAMILY_SH2A) {
extern void __weak sh2a_cache_init(void);
sh2a_cache_init();
}
if (boot_cpu_data.family == CPU_FAMILY_SH3) {
extern void __weak sh3_cache_init(void);
sh3_cache_init();
if ((boot_cpu_data.type == CPU_SH7705) &&
(boot_cpu_data.dcache.sets == 512)) {
extern void __weak sh7705_cache_init(void);
sh7705_cache_init();
}
}
if ((boot_cpu_data.family == CPU_FAMILY_SH4) ||
(boot_cpu_data.family == CPU_FAMILY_SH4A) ||
(boot_cpu_data.family == CPU_FAMILY_SH4AL_DSP)) {
extern void __weak sh4_cache_init(void);
sh4_cache_init();
if ((boot_cpu_data.type == CPU_SH7786) ||
(boot_cpu_data.type == CPU_SHX3)) {
extern void __weak shx3_cache_init(void);
shx3_cache_init();
}
}
if (boot_cpu_data.family == CPU_FAMILY_SH5) {
extern void __weak sh5_cache_init(void);
sh5_cache_init();
}
skip:
emit_cache_params();
}