Re: [PATCH v4 16/24] fpga: dfl: add fpga manager platform driver for FME

From: Wu Hao
Date: Fri Apr 06 2018 - 07:22:06 EST


On Thu, Apr 05, 2018 at 01:45:07PM -0500, Alan Tull wrote:
> On Thu, Mar 22, 2018 at 1:07 AM, Wu Hao <hao.wu@xxxxxxxxx> wrote:
> > On Wed, Mar 21, 2018 at 09:55:52AM -0700, Moritz Fischer wrote:
> >> On Wed, Mar 21, 2018 at 10:50:01AM +0800, Wu Hao wrote:
> >> > On Tue, Mar 20, 2018 at 03:32:34PM -0500, Alan Tull wrote:
> >> > > On Tue, Feb 13, 2018 at 3:24 AM, Wu Hao <hao.wu@xxxxxxxxx> wrote:
> >> > >
> >> > > Hi Hao,
> >> > >
> >> > > Elsewhere we discussed moving #defines used only in this driver either
> >> > > to this .c file or to a similarly named .h file. A couple minor
> >> > > things below.
> >> >
> >> > Hi Alan,
> >> >
> >> > Yes, I will move those #defines into a similarly named .h file.
> >> >
> >> > >
> >> > > > This patch adds fpga manager driver for FPGA Management Engine (FME). It
> >> > > > implements fpga_manager_ops for FPGA Partial Reconfiguration function.
> >> > > >
> >> > > > Signed-off-by: Tim Whisonant <tim.whisonant@xxxxxxxxx>
> >> > > > Signed-off-by: Enno Luebbers <enno.luebbers@xxxxxxxxx>
> >> > > > Signed-off-by: Shiva Rao <shiva.rao@xxxxxxxxx>
> >> > > > Signed-off-by: Christopher Rauer <christopher.rauer@xxxxxxxxx>
> >> > > > Signed-off-by: Kang Luwei <luwei.kang@xxxxxxxxx>
> >> > > > Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
> >> > > > Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx>
> >> > > > ---
> >> > > > v3: rename driver to dfl-fpga-fme-mgr
> >> > > > implemented status callback for fpga manager
> >> > > > rebased due to fpga api changes
> >> > > > v4: rename to dfl-fme-mgr, and fix SPDX license issue
> >> > > > add pr_credit comments and improve dev_err message
> >> > > > remove interface_id sysfs interface
> >> > > > include dfl-fme-pr.h instead of dfl.h
> >> > > > ---
> >> > > > drivers/fpga/Kconfig | 6 +
> >> > > > drivers/fpga/Makefile | 1 +
> >> > > > drivers/fpga/dfl-fme-mgr.c | 290 +++++++++++++++++++++++++++++++++++++++++++++
> >> > > > 3 files changed, 297 insertions(+)
> >> > > > create mode 100644 drivers/fpga/dfl-fme-mgr.c
> >> > > >
> >> > > > diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> >> > > > index 103d5e2..89f76e8 100644
> >> > > > --- a/drivers/fpga/Kconfig
> >> > > > +++ b/drivers/fpga/Kconfig
> >> > > > @@ -150,6 +150,12 @@ config FPGA_DFL_FME
> >> > > > FPGA platform level management features. There shall be 1 FME
> >> > > > per DFL based FPGA device.
> >> > > >
> >> > > > +config FPGA_DFL_FME_MGR
> >> > > > + tristate "FPGA DFL FME Manager Driver"
> >> > > > + depends on FPGA_DFL_FME
> >> > > > + help
> >> > > > + Say Y to enable FPGA Manager driver for FPGA Management Engine.
> >> > > > +
> >> > > > config FPGA_DFL_PCI
> >> > > > tristate "FPGA Device Feature List (DFL) PCIe Device Driver"
> >> > > > depends on PCI && FPGA_DFL
> >> > > > diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> >> > > > index 3c44fc9..f82814a 100644
> >> > > > --- a/drivers/fpga/Makefile
> >> > > > +++ b/drivers/fpga/Makefile
> >> > > > @@ -31,6 +31,7 @@ obj-$(CONFIG_OF_FPGA_REGION) += of-fpga-region.o
> >> > > > # FPGA Device Feature List Support
> >> > > > obj-$(CONFIG_FPGA_DFL) += dfl.o
> >> > > > obj-$(CONFIG_FPGA_DFL_FME) += dfl-fme.o
> >> > > > +obj-$(CONFIG_FPGA_DFL_FME_MGR) += dfl-fme-mgr.o
> >> > > >
> >> > > > dfl-fme-objs := dfl-fme-main.o dfl-fme-pr.o
> >> > > >
> >> > > > diff --git a/drivers/fpga/dfl-fme-mgr.c b/drivers/fpga/dfl-fme-mgr.c
> >> > > > new file mode 100644
> >> > > > index 0000000..2f92c29
> >> > > > --- /dev/null
> >> > > > +++ b/drivers/fpga/dfl-fme-mgr.c
> >> > > > @@ -0,0 +1,290 @@
> >> > > > +// SPDX-License-Identifier: GPL-2.0
> >> > > > +/*
> >> > > > + * FPGA Manager Driver for FPGA Management Engine (FME)
> >> > > > + *
> >> > > > + * Copyright (C) 2017 Intel Corporation, Inc.
> >> > > > + *
> >> > > > + * Authors:
> >> > > > + * Kang Luwei <luwei.kang@xxxxxxxxx>
> >> > > > + * Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
> >> > > > + * Wu Hao <hao.wu@xxxxxxxxx>
> >> > > > + * Joseph Grecco <joe.grecco@xxxxxxxxx>
> >> > > > + * Enno Luebbers <enno.luebbers@xxxxxxxxx>
> >> > > > + * Tim Whisonant <tim.whisonant@xxxxxxxxx>
> >> > > > + * Ananda Ravuri <ananda.ravuri@xxxxxxxxx>
> >> > > > + * Christopher Rauer <christopher.rauer@xxxxxxxxx>
> >> > > > + * Henry Mitchel <henry.mitchel@xxxxxxxxx>
> >> > > > + */
> >> > > > +
> >> > > > +#include <linux/bitfield.h>
> >> > > > +#include <linux/module.h>
> >> > > > +#include <linux/iopoll.h>
> >> > > > +#include <linux/fpga/fpga-mgr.h>
> >> > > > +
> >> > > > +#include "dfl-fme-pr.h"
> >> > > > +
> >> > > > +#define PR_WAIT_TIMEOUT 8000000
> >> > > > +#define PR_HOST_STATUS_IDLE 0
> >> > > > +
> >> > > > +struct fme_mgr_priv {
> >> > > > + void __iomem *ioaddr;
> >> > > > + u64 pr_error;
> >> > > > +};
> >> > > > +
> >> > > > +static u64 pr_error_to_mgr_status(u64 err)
> >> > > > +{
> >> > > > + u64 status = 0;
> >> > > > +
> >> > > > + if (err & FME_PR_ERR_OPERATION_ERR)
> >> > > > + status |= FPGA_MGR_STATUS_OPERATION_ERR;
> >> > > > + if (err & FME_PR_ERR_CRC_ERR)
> >> > > > + status |= FPGA_MGR_STATUS_CRC_ERR;
> >> > > > + if (err & FME_PR_ERR_INCOMPATIBLE_BS)
> >> > > > + status |= FPGA_MGR_STATUS_INCOMPATIBLE_IMAGE_ERR;
> >> > > > + if (err & FME_PR_ERR_PROTOCOL_ERR)
> >> > > > + status |= FPGA_MGR_STATUS_IP_PROTOCOL_ERR;
> >> > > > + if (err & FME_PR_ERR_FIFO_OVERFLOW)
> >> > > > + status |= FPGA_MGR_STATUS_FIFO_OVERFLOW_ERR;
> >> > > > +
> >> > > > + return status;
> >> > > > +}
> >> > > > +
> >> > > > +static u64 fme_mgr_pr_error_handle(void __iomem *fme_pr)
> >> > > > +{
> >> > > > + u64 pr_status, pr_error;
> >> > > > +
> >> > > > + pr_status = readq(fme_pr + FME_PR_STS);
> >> > > > + if (!(pr_status & FME_PR_STS_PR_STS))
> >> > > > + return 0;
> >> > > > +
> >> > > > + pr_error = readq(fme_pr + FME_PR_ERR);
> >> > > > + writeq(pr_error, fme_pr + FME_PR_ERR);
> >> > > > +
> >> > > > + return pr_error;
> >> > > > +}
> >> > > > +
> >> > > > +static int fme_mgr_write_init(struct fpga_manager *mgr,
> >> > > > + struct fpga_image_info *info,
> >> > > > + const char *buf, size_t count)
> >> > > > +{
> >> > > > + struct device *dev = &mgr->dev;
> >> > > > + struct fme_mgr_priv *priv = mgr->priv;
> >> > > > + void __iomem *fme_pr = priv->ioaddr;
> >> > > > + u64 pr_ctrl, pr_status;
> >> > > > +
> >> > > > + if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
> >> > > > + dev_err(dev, "only supports partial reconfiguration.\n");
> >> > > > + return -EINVAL;
> >> > > > + }
> >> > > > +
> >> > > > + dev_dbg(dev, "resetting PR before initiated PR\n");
> >> > > > +
> >> > > > + pr_ctrl = readq(fme_pr + FME_PR_CTRL);
> >> > > > + pr_ctrl |= FME_PR_CTRL_PR_RST;
> >> > > > + writeq(pr_ctrl, fme_pr + FME_PR_CTRL);
> >> > > > +
> >> > > > + if (readq_poll_timeout(fme_pr + FME_PR_CTRL, pr_ctrl,
> >> > > > + pr_ctrl & FME_PR_CTRL_PR_RSTACK, 1,
> >> > > > + PR_WAIT_TIMEOUT)) {
> >> > > > + dev_err(dev, "PR Reset ACK timeout\n");
> >> > > > + return -ETIMEDOUT;
> >> > > > + }
> >> > > > +
> >> > > > + pr_ctrl = readq(fme_pr + FME_PR_CTRL);
> >> > > > + pr_ctrl &= ~FME_PR_CTRL_PR_RST;
> >> > > > + writeq(pr_ctrl, fme_pr + FME_PR_CTRL);
> >> > > > +
> >> > > > + dev_dbg(dev,
> >> > > > + "waiting for PR resource in HW to be initialized and ready\n");
> >> > > > +
> >> > > > + if (readq_poll_timeout(fme_pr + FME_PR_STS, pr_status,
> >> > > > + (pr_status & FME_PR_STS_PR_STS) ==
> >> > > > + FME_PR_STS_PR_STS_IDLE, 1, PR_WAIT_TIMEOUT)) {
> >> > > > + dev_err(dev, "PR Status timeout\n");
> >> > > > + priv->pr_error = fme_mgr_pr_error_handle(fme_pr);
> >> > > > + return -ETIMEDOUT;
> >> > > > + }
> >> > > > +
> >> > > > + dev_dbg(dev, "check and clear previous PR error\n");
> >> > > > + priv->pr_error = fme_mgr_pr_error_handle(fme_pr);
> >> > > > + if (priv->pr_error)
> >> > > > + dev_dbg(dev, "previous PR error detected %llx\n",
> >> > > > + (unsigned long long)priv->pr_error);
> >> > > > +
> >> > > > + dev_dbg(dev, "set PR port ID\n");
> >> > > > +
> >> > > > + pr_ctrl = readq(fme_pr + FME_PR_CTRL);
> >> > > > + pr_ctrl &= ~FME_PR_CTRL_PR_RGN_ID;
> >> > > > + pr_ctrl |= FIELD_PREP(FME_PR_CTRL_PR_RGN_ID, info->region_id);
> >> > > > + writeq(pr_ctrl, fme_pr + FME_PR_CTRL);
> >> > > > +
> >> > > > + return 0;
> >> > > > +}
> >> > > > +
> >> > > > +static int fme_mgr_write(struct fpga_manager *mgr,
> >> > > > + const char *buf, size_t count)
> >> > > > +{
> >> > > > + struct device *dev = &mgr->dev;
> >> > > > + struct fme_mgr_priv *priv = mgr->priv;
> >> > > > + void __iomem *fme_pr = priv->ioaddr;
> >> > > > + u64 pr_ctrl, pr_status, pr_data;
> >> > > > + int delay = 0, pr_credit, i = 0;
> >> > > > +
> >> > > > + dev_dbg(dev, "start request\n");
> >> > > > +
> >> > > > + pr_ctrl = readq(fme_pr + FME_PR_CTRL);
> >> > > > + pr_ctrl |= FME_PR_CTRL_PR_START;
> >> > > > + writeq(pr_ctrl, fme_pr + FME_PR_CTRL);
> >> > > > +
> >> > > > + dev_dbg(dev, "pushing data from bitstream to HW\n");
> >> > > > +
> >> > > > + /*
> >> > > > + * driver can push data to PR hardware using PR_DATA register once HW
> >> > > > + * has enough pr_credit (> 1), pr_credit reduces one for every 32bit
> >> > > > + * pr data write to PR_DATA register. If pr_credit <= 1, driver needs
> >> > > > + * to wait for enough pr_credit from hardware by polling.
> >> > > > + */
> >> > > > + pr_status = readq(fme_pr + FME_PR_STS);
> >> > > > + pr_credit = FIELD_GET(FME_PR_STS_PR_CREDIT, pr_status);
> >> > > > +
> >> > > > + while (count > 0) {
> >> > > > + while (pr_credit <= 1) {
> >> > > > + if (delay++ > PR_WAIT_TIMEOUT) {
> >> > > > + dev_err(dev, "PR_CREDIT timeout\n");
> >> > > > + return -ETIMEDOUT;
> >> > > > + }
> >> > > > + udelay(1);
> >> > > > +
> >> > > > + pr_status = readq(fme_pr + FME_PR_STS);
> >> > > > + pr_credit = FIELD_GET(FME_PR_STS_PR_CREDIT, pr_status);
> >> > > > + }
> >> > > > +
> >> > > > + if (count >= 4) {
> >> > > > + pr_data = 0;
> >> > > > + pr_data |= FIELD_PREP(FME_PR_DATA_PR_DATA_RAW,
> >> > > > + *(((u32 *)buf) + i));
> >> > > > + writeq(pr_data, fme_pr + FME_PR_DATA);
> >> > > > + count -= 4;
> >> > > > + pr_credit--;
> >> > > > + i++;
> >> > > > + } else {
> >> > > > + WARN_ON(1);
> >> > > > + return -EINVAL;
> >> > > > + }
>
> Where there's an if..else that has a 'return' on one of its branch, it
> can become an 'if' without the 'else'. This is strongly preferred in
> the kernel. Trying to avoid indention where possible. So this
> becomes
>
> if (count < 4) {
> WARN_ON(1);
> return -EINVAL;
> }
>
> pr_data = 0;
> so on...

Agree, code looks better with your suggestion.
I will fix this problem in the next verion. Thanks for the comments.

Hao

>
> Alan
>
> >> > > > + }
> >> > > > +
> >> > > > + return 0;
> >> > > > +}
> >> > > > +
> >> > > > +static int fme_mgr_write_complete(struct fpga_manager *mgr,
> >> > > > + struct fpga_image_info *info)
> >> > > > +{
> >> > > > + struct device *dev = &mgr->dev;
> >> > > > + struct fme_mgr_priv *priv = mgr->priv;
> >> > > > + void __iomem *fme_pr = priv->ioaddr;
> >> > > > + u64 pr_ctrl;
> >> > > > +
> >> > > > + pr_ctrl = readq(fme_pr + FME_PR_CTRL);
> >> > > > + pr_ctrl |= FME_PR_CTRL_PR_COMPLETE;
> >> > > > + writeq(pr_ctrl, fme_pr + FME_PR_CTRL);
> >> > > > +
> >> > > > + dev_dbg(dev, "green bitstream push complete\n");
> >> > > > + dev_dbg(dev, "waiting for HW to release PR resource\n");
> >> > > > +
> >> > > > + if (readq_poll_timeout(fme_pr + FME_PR_CTRL, pr_ctrl,
> >> > > > + !(pr_ctrl & FME_PR_CTRL_PR_START), 1,
> >> > > > + PR_WAIT_TIMEOUT)) {
> >> > > > + dev_err(dev, "PR Completion ACK timeout.\n");
> >> > > > + return -ETIMEDOUT;
> >> > > > + }
> >> > > > +
> >> > > > + dev_dbg(dev, "PR operation complete, checking status\n");
> >> > > > + priv->pr_error = fme_mgr_pr_error_handle(fme_pr);
> >> > > > + if (priv->pr_error) {
> >> > > > + dev_dbg(dev, "PR error detected %llx\n",
> >> > > > + (unsigned long long)priv->pr_error);
> >> > > > + return -EIO;
> >> > > > + }
> >> > > > +
> >> > > > + dev_dbg(dev, "PR done successfully\n");
> >> > > > +
> >> > > > + return 0;
> >> > > > +}
> >> > > > +
> >> > > > +static enum fpga_mgr_states fme_mgr_state(struct fpga_manager *mgr)
> >> > > > +{
> >> > > > + return FPGA_MGR_STATE_UNKNOWN;
> >> > > > +}
> >> > > > +
> >> > > > +static u64 fme_mgr_status(struct fpga_manager *mgr)
> >> > > > +{
> >> > > > + struct fme_mgr_priv *priv = mgr->priv;
> >> > > > +
> >> > > > + return pr_error_to_mgr_status(priv->pr_error);
> >> > > > +}
> >> > > > +
> >> > > > +static const struct fpga_manager_ops fme_mgr_ops = {
> >> > > > + .write_init = fme_mgr_write_init,
> >> > > > + .write = fme_mgr_write,
> >> > > > + .write_complete = fme_mgr_write_complete,
> >> > > > + .state = fme_mgr_state,
> >> > > > + .status = fme_mgr_status,
> >> > > > +};
> >> > > > +
> >> > > > +static int fme_mgr_probe(struct platform_device *pdev)
> >> > > > +{
> >> > > > + struct device *dev = &pdev->dev;
> >> > > > + struct fme_mgr_priv *priv;
> >> > > > + struct fpga_manager *mgr;
> >> > > > + struct resource *res;
> >> > > > + int ret;
> >> > > > +
> >> > > > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> >> > > > + if (!priv)
> >> > > > + return -ENOMEM;
> >> > > > +
> >> > > > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> >> > > > + priv->ioaddr = devm_ioremap(dev, res->start, resource_size(res));
> >> > >
> >> > > How about using devm_ioremap_resourc(dev, res) here instead?
> >> >
> >> > Actually the register region has already been mapped in lower level driver
> >> > (e.g pci) so I think we don't have to map the second time here. I plan to
> >> > add some code to pass the ioaddr via the platform data, and check if valid
> >> > ioaddr from the platform data firstly in this probe function. If no pdata
> >> > or no valid ioaddr, then go with devm_ioremap_resource. :)
> >>
> >> If you end up sharing register spaces between drivers is regmap / syscon
> >> maybe a good idea?
> >
> > Hi Moritz,
> >
> > Thanks for the comments. I tried the regmap_mmio before but it failed to use
> > regmap_read and regmap_write for register access. It requires to use writeq /
> > readq for 64bit registers on the hardware, but regmap_read and regmap_write
> > only accepts unsigned int value as input parameter. So I only replaced the
> > bitfields struct/union with macro.
> >
> > Thanks
> > Hao
> >
> >> >
> >> > >
> >> > > > + if (IS_ERR(priv->ioaddr))
> >> > > > + return PTR_ERR(priv->ioaddr);
> >> > > > +
> >> > > > + mgr = devm_kzalloc(dev, sizeof(*mgr), GFP_KERNEL);
> >> > > > + if (!mgr)
> >> > > > + return -ENOMEM;
> >> > > > +
> >> > > > + mgr->name = "DFL FPGA Manager";
> >> > > > + mgr->mops = &fme_mgr_ops;
> >> > > > + mgr->priv = priv;
> >> > > > + mgr->parent = dev;
> >> > > > + platform_set_drvdata(pdev, mgr);
> >> > > > +
> >> > > > + ret = fpga_mgr_register(mgr);
> >> > > > + if (ret)
> >> > > > + dev_err(dev, "unable to register FPGA manager\n");
> >> > > > +
> >> > > > + return ret;
> >> > >
> >> > > You can probably just do "return fpga_mgr_register(mgr);" here.
> >> >
> >> > Yes, it looks better, I will fix it. Thanks a lot for the review.
> >> >
> >> > Hao
> >> >
> >> > >
> >> > > Thanks,
> >> > > Alan
> >> > >
> >> > > > +}
> >> > > > +
> >> > > > +static int fme_mgr_remove(struct platform_device *pdev)
> >> > > > +{
> >> > > > + struct fpga_manager *mgr = platform_get_drvdata(pdev);
> >> > > > +
> >> > > > + fpga_mgr_unregister(mgr);
> >> > > > +
> >> > > > + return 0;
> >> > > > +}
> >> > > > +
> >> > > > +static struct platform_driver fme_mgr_driver = {
> >> > > > + .driver = {
> >> > > > + .name = FPGA_DFL_FME_MGR,
> >> > > > + },
> >> > > > + .probe = fme_mgr_probe,
> >> > > > + .remove = fme_mgr_remove,
> >> > > > +};
> >> > > > +
> >> > > > +module_platform_driver(fme_mgr_driver);
> >> > > > +
> >> > > > +MODULE_DESCRIPTION("FPGA Manager for DFL FPGA Management Engine");
> >> > > > +MODULE_AUTHOR("Intel Corporation");
> >> > > > +MODULE_LICENSE("GPL v2");
> >> > > > +MODULE_ALIAS("platform:dfl-fme-mgr");
> >> > > > --
> >> > > > 2.7.4
> >> > > >
> >>
> >> Cheers,
> >> Moritz
> >> --
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