diff mbox series

[RFC,v9,10/13] arm64/mm, xpfo: temporarily map dcache regions

Message ID a98c81d581e31b573b80ca9982e0325c3f542075.1554248002.git.khalid.aziz@oracle.com (mailing list archive)
State New, archived
Headers show
Series Add support for eXclusive Page Frame Ownership | expand

Commit Message

Khalid Aziz April 3, 2019, 5:34 p.m. UTC 
From: Juerg Haefliger <juerg.haefliger@canonical.com>

If the page is unmapped by XPFO, a data cache flush results in a fatal
page fault, so let's temporarily map the region, flush the cache, and then
unmap it.

CC: linux-arm-kernel@lists.infradead.org
Signed-off-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Tycho Andersen <tycho@tycho.ws>
---
v6: actually flush in the face of xpfo, and temporarily map the underlying
    memory so it can be flushed correctly

 arch/arm64/mm/flush.c | 7 +++++++
 1 file changed, 7 insertions(+)
diff mbox series

Patch

diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index 5c9073bace83..114e8bc5a3dc 100644
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -20,6 +20,7 @@ 
 #include <linux/export.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/xpfo.h>
 
 #include <asm/cacheflush.h>
 #include <asm/cache.h>
@@ -28,9 +29,15 @@ 
 void sync_icache_aliases(void *kaddr, unsigned long len)
 {
 	unsigned long addr = (unsigned long)kaddr;
+	unsigned long num_pages = XPFO_NUM_PAGES(addr, len);
+	void *mapping[num_pages];
 
 	if (icache_is_aliasing()) {
+		xpfo_temp_map(kaddr, len, mapping,
+			      sizeof(mapping[0]) * num_pages);
 		__clean_dcache_area_pou(kaddr, len);
+		xpfo_temp_unmap(kaddr, len, mapping,
+				sizeof(mapping[0]) * num_pages);
 		__flush_icache_all();
 	} else {
 		/*