Re: [PATCH 3/3] fpga manager: Adding FPGA Manager support for Xilinx zynqmp

[Moritz Fischer <moritz.fischer@ettus.com>]

On Fri, Oct 19, 2018 at 2:33 PM Moritz Fischer
<moritz.fischer.private@gmail.com> wrote:
>
> Hi Nava,
>
> Looks good to me, a couple of nits inline below.
>
> On Fri, Oct 19, 2018 at 1:50 AM Nava kishore Manne
> <nava.manne@xilinx.com> wrote:
> >
> > This patch adds FPGA Manager support for the Xilinx
> > ZynqMp chip.
>
> Isn't it ZynqMP ?
> >
> > Signed-off-by: Nava kishore Manne <nava.manne@xilinx.com>
> > ---
> > Changes for v1:
> >                 -None.
> >
> > Changes for RFC-V2:
> >                 -Updated the Fpga Mgr registrations call's
> >                  to 4.18
> >
> >  drivers/fpga/Kconfig       |   9 +++
> >  drivers/fpga/Makefile      |   1 +
> >  drivers/fpga/zynqmp-fpga.c | 159 +++++++++++++++++++++++++++++++++++++
> >  3 files changed, 169 insertions(+)
> >  create mode 100644 drivers/fpga/zynqmp-fpga.c
> >
> > diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> > index 1ebcef4bab5b..26ebbcf3d3a3 100644
> > --- a/drivers/fpga/Kconfig
> > +++ b/drivers/fpga/Kconfig
> > @@ -56,6 +56,15 @@ config FPGA_MGR_ZYNQ_FPGA
> >         help
> >           FPGA manager driver support for Xilinx Zynq FPGAs.
> >
> > +config FPGA_MGR_ZYNQMP_FPGA
> > +       tristate "Xilinx Zynqmp FPGA"
> > +       depends on ARCH_ZYNQMP || COMPILE_TEST
> > +       help
> > +         FPGA manager driver support for Xilinx ZynqMP FPGAs.
> > +         This driver uses processor configuration port(PCAP)
> This driver uses *the* processor configuration port.
>
> > +         to configure the programmable logic(PL) through PS
> > +         on ZynqMP SoC.
> > +
> >  config FPGA_MGR_XILINX_SPI
> >         tristate "Xilinx Configuration over Slave Serial (SPI)"
> >         depends on SPI
> > diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> > index 7a2d73ba7122..3488ebbaee46 100644
> > --- a/drivers/fpga/Makefile
> > +++ b/drivers/fpga/Makefile
> > @@ -16,6 +16,7 @@ obj-$(CONFIG_FPGA_MGR_SOCFPGA_A10)    += socfpga-a10.o
> >  obj-$(CONFIG_FPGA_MGR_TS73XX)          += ts73xx-fpga.o
> >  obj-$(CONFIG_FPGA_MGR_XILINX_SPI)      += xilinx-spi.o
> >  obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)       += zynq-fpga.o
> > +obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA)     += zynqmp-fpga.o
> >  obj-$(CONFIG_ALTERA_PR_IP_CORE)         += altera-pr-ip-core.o
> >  obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT)    += altera-pr-ip-core-plat.o
> >
> > diff --git a/drivers/fpga/zynqmp-fpga.c b/drivers/fpga/zynqmp-fpga.c
> > new file mode 100644
> > index 000000000000..2760d7e3872a
> > --- /dev/null
> > +++ b/drivers/fpga/zynqmp-fpga.c
> > @@ -0,0 +1,159 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Copyright (C) 2018 Xilinx, Inc.
> > + */
> > +
> > +#include <linux/dma-mapping.h>
> > +#include <linux/fpga/fpga-mgr.h>
> > +#include <linux/io.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/of_address.h>
> > +#include <linux/string.h>
> > +#include <linux/firmware/xlnx-zynqmp.h>
> > +
> > +/* Constant Definitions */
> > +#define IXR_FPGA_DONE_MASK     0X00000008U
> > +
> > +/**
> > + * struct zynqmp_fpga_priv - Private data structure
> > + * @dev:       Device data structure
> > + * @flags:     flags which is used to identify the bitfile type
> > + */
> > +struct zynqmp_fpga_priv {
> > +       struct device *dev;
> > +       u32 flags;
> > +};
> > +
> > +static int zynqmp_fpga_ops_write_init(struct fpga_manager *mgr,
> > +                                     struct fpga_image_info *info,
> > +                                     const char *buf, size_t size)
> > +{
> > +       struct zynqmp_fpga_priv *priv;
> > +
> > +       priv = mgr->priv;
> > +       priv->flags = info->flags;
> > +
> > +       return 0;
> > +}
> > +
> > +static int zynqmp_fpga_ops_write(struct fpga_manager *mgr,
> > +                                const char *buf, size_t size)
> > +{
> > +       struct zynqmp_fpga_priv *priv;
> > +       char *kbuf;
> > +       dma_addr_t dma_addr;
> > +       int ret;
> > +       const struct zynqmp_eemi_ops *eemi_ops = zynqmp_pm_get_eemi_ops();
>
> Reverse xmas-tree please, i.e. long lines first.
>
> > +
> > +       if (!eemi_ops || !eemi_ops->fpga_load)
> > +               return -ENXIO;
> > +
> > +       priv = mgr->priv;
> > +
> > +       kbuf = dma_alloc_coherent(priv->dev, size, &dma_addr, GFP_KERNEL);
> > +       if (!kbuf)
> > +               return -ENOMEM;
> > +
> > +       memcpy(kbuf, buf, size);
> > +
> > +       wmb(); /* ensure all writes are done before initiate FW call */
> > +
> > +       ret = eemi_ops->fpga_load(dma_addr, size, priv->flags);

Don't you have to do anything with the flags? Is it really just a
pass-through of
FPGA manager flags to eemi calls?

Don't you want to make partial bitstreams e.g. use a flags value that
you export in your
firmware header (xlnx-zynqmp.h) and set those based on what flags get passed in,
i.e. explicitely translate FPGA Manager flags to your firmware flags?

Thanks,

Moritz