diff options
authorJohn David Anglin <>2022-06-18 15:14:34 +0000
committerHelge Deller <>2022-06-26 12:23:15 +0200
commite9ed22e6e5010997a2f922eef61ca797d0a2a246 (patch)
parentd16c5c7c925658ea94689dfe4469441f7fd59f00 (diff)
parisc: Fix flush_anon_page on PA8800/PA8900
Anonymous pages are allocated with the shared mappings colouring, SHM_COLOUR. Since the alias boundary on machines with PA8800 and PA8900 processors is unknown, flush_user_cache_page() might not flush all mappings of a shared anonymous page. Flushing the whole data cache flushes all mappings. This won't fix all coherency issues with shared mappings but it seems to work well in practice. I haven't seen any random memory faults in almost a month on a rp3440 running as a debian buildd machine. There is a small preformance hit. Signed-off-by: John David Anglin <> Signed-off-by: Helge Deller <> Cc: # v5.18+
1 files changed, 4 insertions, 1 deletions
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index c8a11fcecf4c..a9bc578e4c52 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -722,7 +722,10 @@ void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned lon
if (parisc_requires_coherency()) {
- flush_user_cache_page(vma, vmaddr);
+ if (vma->vm_flags & VM_SHARED)
+ flush_data_cache();
+ else
+ flush_user_cache_page(vma, vmaddr);