drm: add helper to clflush a virtual address range
Useful when the page is already mapped to copy date in/out.
For -stable because the next patch (fixing phys obj pwrite) needs this
little helper function.
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index 5928653..c7c8f6b 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -98,3 +98,26 @@
#endif
}
EXPORT_SYMBOL(drm_clflush_pages);
+
+void
+drm_clflush_virt_range(char *addr, unsigned long length)
+{
+#if defined(CONFIG_X86)
+ if (cpu_has_clflush) {
+ char *end = addr + length;
+ mb();
+ for (; addr < end; addr += boot_cpu_data.x86_clflush_size)
+ clflush(addr);
+ clflush(end - 1);
+ mb();
+ return;
+ }
+
+ if (on_each_cpu(drm_clflush_ipi_handler, NULL, 1) != 0)
+ printk(KERN_ERR "Timed out waiting for cache flush.\n");
+#else
+ printk(KERN_ERR "Architecture has no drm_cache.c support\n");
+ WARN_ON_ONCE(1);
+#endif
+}
+EXPORT_SYMBOL(drm_clflush_virt_range);