[PATCH] parisc: Avoid flushing cache on cache-less machines

[Helge Deller <deller@xxxxxx>]

Avoid flushing caches in __flush_cache_page() and __purge_cache_page()
if the machine hasn't data or instruction caches - as e.g. in qemu.

Signed-off-by: Helge Deller <deller@xxxxxx>
---
 arch/parisc/kernel/cache.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 231cebb3fc0d..d41fee3a9874 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -315,6 +315,8 @@ static inline void
 __flush_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
 		   unsigned long physaddr)
 {
+	if (!static_branch_likely(&parisc_has_cache))
+		return;
 	preempt_disable();
 	flush_dcache_page_asm(physaddr, vmaddr);
 	if (vma->vm_flags & VM_EXEC)
@@ -326,6 +328,8 @@ static inline void
 __purge_cache_page(struct vm_area_struct *vma, unsigned long vmaddr,
 		   unsigned long physaddr)
 {
+	if (!static_branch_likely(&parisc_has_cache))
+		return;
 	preempt_disable();
 	purge_dcache_page_asm(physaddr, vmaddr);
 	if (vma->vm_flags & VM_EXEC)
--
2.35.1