agp: add chipset flushing support to AGP interface

This bumps the AGP interface to 0.103.

Certain Intel chipsets contains a global write buffer, and this can require
flushing from the drm or X.org to make sure all data has hit RAM before
initiating a GPU transfer, due to a lack of coherency with the integrated
graphics device and this buffer.

This just adds generic support to the AGP interfaces, a follow-on patch
will add support to the Intel driver to use this interface.

Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/char/agp/agp.h

@@ -117,7 +117,8 @@ struct agp_bridge_driver {
 	void (*free_by_type)(struct agp_memory *);
 	void *(*agp_alloc_page)(struct agp_bridge_data *);
 	void (*agp_destroy_page)(void *, int flags);
-        int (*agp_type_to_mask_type) (struct agp_bridge_data *, int);
+	int (*agp_type_to_mask_type) (struct agp_bridge_data *, int);
+	void (*chipset_flush)(struct agp_bridge_data *);
 };
 
 struct agp_bridge_data {

drivers/char/agp/backend.c

@@ -43,7 +43,7 @@
  * fix some real stupidity. It's only by chance we can bump
  * past 0.99 at all due to some boolean logic error. */
 #define AGPGART_VERSION_MAJOR 0
-#define AGPGART_VERSION_MINOR 102
+#define AGPGART_VERSION_MINOR 103
 static const struct agp_version agp_current_version =
 {
 	.major = AGPGART_VERSION_MAJOR,

drivers/char/agp/compat_ioctl.c

@@ -273,6 +273,10 @@ long compat_agp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	case AGPIOC_UNBIND32:
 		ret_val = compat_agpioc_unbind_wrap(curr_priv, (void __user *) arg);
 		break;
+
+	case AGPIOC_CHIPSET_FLUSH32:
+		ret_val = agpioc_chipset_flush_wrap(curr_priv);
+		break;
 	}
 
 ioctl_out:

drivers/char/agp/compat_ioctl.h

@@ -39,6 +39,7 @@
 #define AGPIOC_DEALLOCATE32 _IOW (AGPIOC_BASE, 7, compat_int_t)
 #define AGPIOC_BIND32       _IOW (AGPIOC_BASE, 8, compat_uptr_t)
 #define AGPIOC_UNBIND32     _IOW (AGPIOC_BASE, 9, compat_uptr_t)
+#define AGPIOC_CHIPSET_FLUSH32 _IO (AGPIOC_BASE, 10)
 
 struct agp_info32 {
 	struct agp_version version;	/* version of the driver        */
@@ -101,5 +102,6 @@ void agp_free_memory_wrap(struct agp_memory *memory);
 struct agp_memory *agp_allocate_memory_wrap(size_t pg_count, u32 type);
 struct agp_memory *agp_find_mem_by_key(int key);
 struct agp_client *agp_find_client_by_pid(pid_t id);
+int agpioc_chipset_flush_wrap(struct agp_file_private *priv);
 
 #endif /* _AGP_COMPAT_H */

drivers/char/agp/frontend.c

@@ -960,6 +960,13 @@ static int agpioc_unbind_wrap(struct agp_file_private *priv, void __user *arg)
 	return agp_unbind_memory(memory);
 }
 
+int agpioc_chipset_flush_wrap(struct agp_file_private *priv)
+{
+	DBG("");
+	agp_flush_chipset(agp_bridge);
+	return 0;
+}
+
 static int agp_ioctl(struct inode *inode, struct file *file,
 		     unsigned int cmd, unsigned long arg)
 {
@@ -1033,6 +1040,10 @@ static int agp_ioctl(struct inode *inode, struct file *file,
 	case AGPIOC_UNBIND:
 		ret_val = agpioc_unbind_wrap(curr_priv, (void __user *) arg);
 		break;
+
+	case AGPIOC_CHIPSET_FLUSH:
+		ret_val = agpioc_chipset_flush_wrap(curr_priv);
+		break;
 	}
 
 ioctl_out:

drivers/char/agp/generic.c

@@ -80,6 +80,13 @@ static int agp_get_key(void)
 	return -1;
 }
 
+void agp_flush_chipset(struct agp_bridge_data *bridge)
+{
+	if (bridge->driver->chipset_flush)
+		bridge->driver->chipset_flush(bridge);
+}
+EXPORT_SYMBOL(agp_flush_chipset);
+
 /*
  * Use kmalloc if possible for the page list. Otherwise fall back to
  * vmalloc. This speeds things up and also saves memory for small AGP

include/linux/agp_backend.h

@@ -109,6 +109,7 @@ extern int agp_unbind_memory(struct agp_memory *);
 extern void agp_enable(struct agp_bridge_data *, u32);
 extern struct agp_bridge_data *agp_backend_acquire(struct pci_dev *);
 extern void agp_backend_release(struct agp_bridge_data *);
+extern void agp_flush_chipset(struct agp_bridge_data *);
 
 #endif				/* __KERNEL__ */
 #endif				/* _AGP_BACKEND_H */

include/linux/agpgart.h

@@ -38,6 +38,7 @@
 #define AGPIOC_DEALLOCATE _IOW (AGPIOC_BASE, 7, int)
 #define AGPIOC_BIND       _IOW (AGPIOC_BASE, 8, struct agp_bind*)
 #define AGPIOC_UNBIND     _IOW (AGPIOC_BASE, 9, struct agp_unbind*)
+#define AGPIOC_CHIPSET_FLUSH _IO (AGPIOC_BASE, 10)
 
 #define AGP_DEVICE      "/dev/agpgart"