fpga: Add scatterlist based programming
Requiring contiguous kernel memory is not a good idea, this is a limited
resource and allocation can fail under normal work loads.
This introduces a .write_sg op that supporting drivers can provide
to DMA directly from dis-contiguous memory and a new entry point
fpga_mgr_buf_load_sg that users can call to directly provide page
lists.
The full matrix of compatibility is provided, either the linear or sg
interface can be used by the user with a driver supporting either
interface.
A notable change for drivers is that the .write op can now be called
multiple times.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Acked-by: Alan Tull <atull@opensource.altera.com>
Acked-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/fpga/fpga-mgr.h b/include/linux/fpga/fpga-mgr.h
index 16551d5..57beb5d 100644
--- a/include/linux/fpga/fpga-mgr.h
+++ b/include/linux/fpga/fpga-mgr.h
@@ -22,6 +22,7 @@
#define _LINUX_FPGA_MGR_H
struct fpga_manager;
+struct sg_table;
/**
* enum fpga_mgr_states - fpga framework states
@@ -88,6 +89,7 @@ struct fpga_image_info {
* @state: returns an enum value of the FPGA's state
* @write_init: prepare the FPGA to receive confuration data
* @write: write count bytes of configuration data to the FPGA
+ * @write_sg: write the scatter list of configuration data to the FPGA
* @write_complete: set FPGA to operating state after writing is done
* @fpga_remove: optional: Set FPGA into a specific state during driver remove
*
@@ -102,6 +104,7 @@ struct fpga_manager_ops {
struct fpga_image_info *info,
const char *buf, size_t count);
int (*write)(struct fpga_manager *mgr, const char *buf, size_t count);
+ int (*write_sg)(struct fpga_manager *mgr, struct sg_table *sgt);
int (*write_complete)(struct fpga_manager *mgr,
struct fpga_image_info *info);
void (*fpga_remove)(struct fpga_manager *mgr);
@@ -129,6 +132,8 @@ struct fpga_manager {
int fpga_mgr_buf_load(struct fpga_manager *mgr, struct fpga_image_info *info,
const char *buf, size_t count);
+int fpga_mgr_buf_load_sg(struct fpga_manager *mgr, struct fpga_image_info *info,
+ struct sg_table *sgt);
int fpga_mgr_firmware_load(struct fpga_manager *mgr,
struct fpga_image_info *info,