Borrow from ARM64
MIPS64 CPU has enough direct mapped memory space to access all
physical memory. In case of no cache alias, bypass both kmap_atomic
and kmap_coherent for better real-time performance.
Signed-off-by: Huang Pei <redacted>
---
arch/mips/mm/init.c | 37 +++++++++++++++++++++++++------------
1 file changed, 25 insertions(+), 12 deletions(-)
diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c
index 325e1552cbea..54f8464fbb95 100644
--- a/arch/mips/mm/init.c
+++ b/arch/mips/mm/init.c
@@ -171,21 +171,34 @@ void copy_user_highpage(struct page *to, struct page *from,
{
void *vfrom, *vto;
- vto = kmap_atomic(to);
- if (cpu_has_dc_aliases &&
- page_mapcount(from) && !Page_dcache_dirty(from)) {
- vfrom = kmap_coherent(from, vaddr);
+ if (IS_ENABLED(CONFIG_64BIT) && !cpu_has_dc_aliases) {
+ vfrom = page_address(from);
+ vto = page_address(to);
copy_page(vto, vfrom);
- kunmap_coherent();
+ /*
+ * even without cache alias, still need to maintain
+ * coherence between icache and dcache
+ */
+ if (!cpu_has_ic_fills_f_dc)
+ flush_data_cache_page((unsigned long)vto);
+
} else {
- vfrom = kmap_atomic(from);
- copy_page(vto, vfrom);
- kunmap_atomic(vfrom);
+ vto = kmap_atomic(to);
+ if (cpu_has_dc_aliases &&
+ page_mapcount(from) && !Page_dcache_dirty(from)) {
+ vfrom = kmap_coherent(from, vaddr);
+ copy_page(vto, vfrom);
+ kunmap_coherent();
+ } else {
+ vfrom = kmap_atomic(from);
+ copy_page(vto, vfrom);
+ kunmap_atomic(vfrom);
+ }
+ if ((!cpu_has_ic_fills_f_dc) ||
+ pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
+ flush_data_cache_page((unsigned long)vto);
+ kunmap_atomic(vto);
}
- if ((!cpu_has_ic_fills_f_dc) ||
- pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
- flush_data_cache_page((unsigned long)vto);
- kunmap_atomic(vto);
/* Make sure this page is cleared on other CPU's too before using it */
smp_wmb();
}--
2.20.1