[PATCH 06/13] drm: add helper to clflush a virtual address range

[Daniel Vetter]

Useful when the page is already mapped to copy date in/out.

Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
---
 drivers/gpu/drm/drm_cache.c |   23 +++++++++++++++++++++++
 include/drm/drmP.h          |    1 +
 2 files changed, 24 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/drm_cache.c b/drivers/gpu/drm/drm_cache.c
index 0e3bd5b..502771a 100644
--- a/drivers/gpu/drm/drm_cache.c
+++ b/drivers/gpu/drm/drm_cache.c
@@ -97,3 +97,26 @@ drm_clflush_pages(struct page *pages[], unsigned long 
num_pages)
 #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);
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 43538b6..a082640 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1328,6 +1328,7 @@ extern int drm_authmagic(struct drm_device *dev, void 
*data,

 /* Cache management (drm_cache.c) */
 void drm_clflush_pages(struct page *pages[], unsigned long num_pages);
+void drm_clflush_virt_range(char *addr, unsigned long length);

                                /* Locking IOCTL support (drm_lock.h) */
 extern int drm_lock(struct drm_device *dev, void *data,
-- 
1.7.6.4