This is a note to let you know that I have just added a patch titled
MIPS: Handle highmem pages in __update_cache
to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree
which can be found at:
https://git.launchpad.net/~canonical-kernel/linux/+git/linux-stable-ckt/log/?h=linux-4.2.y-queue
This patch is scheduled to be released in version 4.2.8-ckt12.
If you, or anyone else, feels it should not be added to this tree, please
reply to this email.
For more information about the 4.2.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable
Thanks.
-Kamal
---8<------------------------------------------------------------
>From 583490f1157a28699ea9b992d78e78c009527f53 Mon Sep 17 00:00:00 2001
From: Paul Burton <paul.burton@xxxxxxxxxx>
Date: Tue, 1 Mar 2016 02:37:58 +0000
Subject: MIPS: Handle highmem pages in __update_cache
commit f4281bba818105c7c91799abe40bc05c0dbdaa25 upstream.
The following patch will expose __update_cache to highmem pages. Handle
them by mapping them in for the duration of the cache maintenance, just
like in __flush_dcache_page. The code for that isn't shared because we
need the page address in __update_cache so sharing became messy. Given
that the entirity is an extra 5 lines, just duplicate it.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: Lars Persson <lars.persson@xxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Jerome Marchand <jmarchan@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/12721/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
arch/mips/mm/cache.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index aab218c..0d71fdd 100644
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -143,9 +143,17 @@ void __update_cache(struct vm_area_struct *vma, unsigned long address,
return;
page = pfn_to_page(pfn);
if (page_mapping(page) && Page_dcache_dirty(page)) {
- addr = (unsigned long) page_address(page);
+ if (PageHighMem(page))
+ addr = (unsigned long)kmap_atomic(page);
+ else
+ addr = (unsigned long)page_address(page);
+
if (exec || pages_do_alias(addr, address & PAGE_MASK))
flush_data_cache_page(addr);
+
+ if (PageHighMem(page))
+ __kunmap_atomic((void *)addr);
+
ClearPageDcacheDirty(page);
}
}
--
2.7.4
