The existing .write callback allocates a DMA-coherent buffer and copies the image into it before passing the address to firmware. With dma-buf, the buffer is already DMA-mapped by userspace.
Add a .write_sg callback that extracts the DMA address directly from the scatter-gather table and passes it to zynqmp_pm_load_pdi(), avoiding the intermediate copy. Register the dma-buf interface in probe with devres-managed cleanup. Co-developed-by: Nava kishore Manne <[email protected]> Signed-off-by: Nava kishore Manne <[email protected]> Signed-off-by: Aravind Thokala <[email protected]> --- drivers/fpga/versal-fpga.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) diff --git a/drivers/fpga/versal-fpga.c b/drivers/fpga/versal-fpga.c index e6189106c468..bdaa15a6c991 100644 --- a/drivers/fpga/versal-fpga.c +++ b/drivers/fpga/versal-fpga.c @@ -4,6 +4,7 @@ */ #include <linux/dma-mapping.h> +#include <linux/fpga/fpga-dmabuf.h> #include <linux/fpga/fpga-mgr.h> #include <linux/io.h> #include <linux/kernel.h> @@ -37,11 +38,34 @@ static int versal_fpga_ops_write(struct fpga_manager *mgr, return ret; } +static int versal_fpga_ops_write_sg(struct fpga_manager *mgr, + struct sg_table *sgt) +{ + dma_addr_t dma_addr; + + /* zynqmp_pm_load_pdi() takes a single base address */ + if (sgt->nents != 1) { + dev_err(&mgr->dev, "dma-buf has %u segments, need exactly 1\n", + sgt->nents); + return -EINVAL; + } + + dma_addr = sg_dma_address(sgt->sgl); + + return zynqmp_pm_load_pdi(PDI_SRC_DDR, dma_addr); +} + static const struct fpga_manager_ops versal_fpga_ops = { .write_init = versal_fpga_ops_write_init, .write = versal_fpga_ops_write, + .write_sg = versal_fpga_ops_write_sg, }; +static void versal_fpga_dmabuf_remove(void *data) +{ + fpga_dmabuf_unregister(data); +} + static int versal_fpga_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -56,7 +80,14 @@ static int versal_fpga_probe(struct platform_device *pdev) mgr = devm_fpga_mgr_register(dev, "Xilinx Versal FPGA Manager", &versal_fpga_ops, NULL); - return PTR_ERR_OR_ZERO(mgr); + if (IS_ERR(mgr)) + return PTR_ERR(mgr); + + ret = fpga_dmabuf_register(mgr); + if (ret) + return ret; + + return devm_add_action_or_reset(dev, versal_fpga_dmabuf_remove, mgr); } static const struct of_device_id versal_fpga_of_match[] = { -- 2.34.1
