dmaengine: DMA engine driver for Marvell XOR engine

The XOR engine found in Marvell's SoCs and system controllers
provides XOR and DMA operation, iSCSI CRC32C calculation, memory
initialization, and memory ECC error cleanup operation support.

This driver implements the DMA engine API and supports the following
capabilities:
- memcpy
- xor
- memset

The XOR engine can be used by DMA engine clients implemented in the
kernel, one of those clients is the RAID module.  In that case, I
observed 20% improvement in the raid5 write throughput, and 40%
decrease in the CPU utilization when doing array construction, those
results obtained on an 5182 running at 500Mhz.

When enabling the NET DMA client, the performance decreased, so
meanwhile it is recommended to keep this client off.

Signed-off-by: Saeed Bishara <saeed@marvell.com>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/include/asm-arm/plat-orion/mv_xor.h b/include/asm-arm/plat-orion/mv_xor.h
new file mode 100644
index 000000000000..c349e8ff5cc0
--- /dev/null
+++ b/include/asm-arm/plat-orion/mv_xor.h
@@ -0,0 +1,28 @@
+/*
+ * Marvell XOR platform device data definition file.
+ */
+
+#ifndef __ASM_PLAT_ORION_MV_XOR_H
+#define __ASM_PLAT_ORION_MV_XOR_H
+
+#include <linux/dmaengine.h>
+#include <linux/mbus.h>
+
+#define MV_XOR_SHARED_NAME      "mv_xor_shared"
+#define MV_XOR_NAME             "mv_xor"
+
+struct mbus_dram_target_info;
+
+struct mv_xor_platform_shared_data {
+        struct mbus_dram_target_info    *dram;
+};
+
+struct mv_xor_platform_data {
+        struct platform_device          *shared;
+        int                             hw_id;
+        dma_cap_mask_t                  cap_mask;
+        size_t                          pool_size;
+};
+
+
+#endif