[PATCH RFC 3/3] fpga: zynqmp: Use the scatterlist interface

From: Nava kishore Manne
Date: Fri Apr 02 2021 - 05:18:28 EST


Allows drivers to request the Configuration image
be loaded from dma-able continuous buffer to avoid
needless memory pressure and delays due to multiple
copies.

Signed-off-by: Nava kishore Manne <nava.manne@xxxxxxxxxx>
---
drivers/fpga/zynqmp-fpga.c | 35 +++++++++++++++++++++++++++++++++++
1 file changed, 35 insertions(+)

diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
index 125743c9797f..3bb6bd520d71 100644
--- a/drivers/fpga/zynqmp-fpga.c
+++ b/drivers/fpga/zynqmp-fpga.c
@@ -66,6 +66,40 @@ static int zynqmp_fpga_ops_write(struct fpga_manager *mgr,
return ret;
}

+static unsigned long zynqmp_fpga_get_contiguous_size(struct sg_table *sgt)
+{
+ dma_addr_t expected = sg_dma_address(sgt->sgl);
+ unsigned long size = 0;
+ struct scatterlist *s;
+ unsigned int i;
+
+ for_each_sg(sgt->sgl, s, sgt->nents, i) {
+ if (sg_dma_address(s) != expected)
+ break;
+ expected = sg_dma_address(s) + sg_dma_len(s);
+ size += sg_dma_len(s);
+ }
+
+ return size;
+}
+
+static int zynqmp_fpga_ops_write_sg(struct fpga_manager *mgr,
+ struct sg_table *sgt)
+{
+ struct zynqmp_fpga_priv *priv;
+ unsigned long contig_size;
+ dma_addr_t dma_addr;
+ u32 eemi_flags = 0;
+
+ priv = mgr->priv;
+ dma_addr = sg_dma_address(sgt->sgl);
+ contig_size = zynqmp_fpga_get_contiguous_size(sgt);
+ if (priv->flags & FPGA_MGR_PARTIAL_RECONFIG)
+ eemi_flags |= XILINX_ZYNQMP_PM_FPGA_PARTIAL;
+
+ return zynqmp_pm_fpga_load(dma_addr, contig_size, eemi_flags);
+}
+
static int zynqmp_fpga_ops_write_complete(struct fpga_manager *mgr,
struct fpga_image_info *info)
{
@@ -87,6 +121,7 @@ static const struct fpga_manager_ops zynqmp_fpga_ops = {
.state = zynqmp_fpga_ops_state,
.write_init = zynqmp_fpga_ops_write_init,
.write = zynqmp_fpga_ops_write,
+ .write_sg = zynqmp_fpga_ops_write_sg,
.write_complete = zynqmp_fpga_ops_write_complete,
};

--
2.18.0