On Sun, Dec 06, 2020 at 01:55:54PM -0800, trix@xxxxxxxxxx wrote: > From: Tom Rix <trix@xxxxxxxxxx> > > >From [PATCH 0/2] UIO support for dfl devices > https://lore.kernel.org/linux-fpga/1602828151-24784-1-git-send-email-yilun.xu@xxxxxxxxx/ Why is this here? > > Here is an idea to have uio support with no driver override. > > This makes UIO the primary driver interface because every feature > will have one and makes the existing platform driver interface > secondary. There will be a new burden for locking write access when > they compete. > > Example shows finding the fpga's temperture. > > Signed-off-by: Tom Rix <trix@xxxxxxxxxx> > --- > drivers/fpga/dfl-fme-main.c | 9 +++- > drivers/fpga/dfl-uio.c | 96 +++++++++++++++++++++++++++++++++++++ > drivers/fpga/dfl.c | 44 ++++++++++++++++- > drivers/fpga/dfl.h | 9 ++++ > uio.c | 56 ++++++++++++++++++++++ > 5 files changed, 212 insertions(+), 2 deletions(-) > create mode 100644 drivers/fpga/dfl-uio.c > create mode 100644 uio.c > > diff --git a/drivers/fpga/dfl-fme-main.c b/drivers/fpga/dfl-fme-main.c > index 037dc4f946f0..3323e90a18c4 100644 > --- a/drivers/fpga/dfl-fme-main.c > +++ b/drivers/fpga/dfl-fme-main.c > @@ -709,12 +709,18 @@ static int fme_probe(struct platform_device *pdev) > if (ret) > goto dev_destroy; > > - ret = dfl_fpga_dev_ops_register(pdev, &fme_fops, THIS_MODULE); > + ret = dfl_fpga_dev_feature_init_uio(pdev, DFH_TYPE_FIU); > if (ret) > goto feature_uinit; > > + ret = dfl_fpga_dev_ops_register(pdev, &fme_fops, THIS_MODULE); > + if (ret) > + goto feature_uinit_uio; > + > return 0; > > +feature_uinit_uio: > + dfl_fpga_dev_feature_uinit_uio(pdev, DFH_TYPE_FIU); > feature_uinit: > dfl_fpga_dev_feature_uinit(pdev); > dev_destroy: > @@ -726,6 +732,7 @@ exit: > static int fme_remove(struct platform_device *pdev) > { > dfl_fpga_dev_ops_unregister(pdev); > + dfl_fpga_dev_feature_uinit_uio(pdev, DFH_TYPE_FIU); > dfl_fpga_dev_feature_uinit(pdev); > fme_dev_destroy(pdev); > > diff --git a/drivers/fpga/dfl-uio.c b/drivers/fpga/dfl-uio.c > new file mode 100644 > index 000000000000..7610ee0b19dc > --- /dev/null > +++ b/drivers/fpga/dfl-uio.c > @@ -0,0 +1,96 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > +/* > + * prototype dfl uio driver > + * > + * Copyright Tom Rix 2020 > + */ > +#include <linux/module.h> > +#include "dfl.h" > + > +static irqreturn_t dfl_uio_handler(int irq, struct uio_info *info) > +{ > + return IRQ_HANDLED; > +} > + > +static int dfl_uio_mmap(struct uio_info *info, struct vm_area_struct *vma) > +{ > + int ret = -ENODEV; > + return ret; Did you run this through checkpatch? Does the code make sense? > +} > + > +static int dfl_uio_open(struct uio_info *info, struct inode *inode) > +{ > + int ret = -ENODEV; > + struct dfl_feature *feature = container_of(info, struct dfl_feature, uio); > + if (feature->dev) > + mutex_lock(&feature->lock); > + > + ret = 0; > + return ret; Same here, does this make sense? And wait, you are having userspace grab a kernel lock? What could go wrong? :( > +} > + > +static int dfl_uio_release(struct uio_info *info, struct inode *inode) > +{ > + int ret = -ENODEV; > + struct dfl_feature *feature = container_of(info, struct dfl_feature, uio); > + if (feature->dev) > + mutex_unlock(&feature->lock); > + > + ret = 0; > + return ret; > +} > + > +static int dfl_uio_irqcontrol(struct uio_info *info, s32 irq_on) > +{ > + int ret = -ENODEV; > + return ret; > +} > + > +int dfl_uio_add(struct dfl_feature *feature) > +{ > + struct uio_info *uio = &feature->uio; > + struct resource *res = > + &feature->dev->resource[feature->resource_index]; > + int ret = 0; > + > + uio->name = kasprintf(GFP_KERNEL, "dfl-uio-%llx", feature->id); > + if (!uio->name) { > + ret = -ENOMEM; > + goto exit; > + } > + > + uio->version = "0.1"; > + uio->mem[0].memtype = UIO_MEM_PHYS; > + uio->mem[0].addr = res->start & PAGE_MASK; > + uio->mem[0].offs = res->start & ~PAGE_MASK; > + uio->mem[0].size = (uio->mem[0].offs + resource_size(res) > + + PAGE_SIZE - 1) & PAGE_MASK; > + /* How are nr_irqs > 1 handled ??? */ > + if (feature->nr_irqs == 1) > + uio->irq = feature->irq_ctx[0].irq; > + uio->handler = dfl_uio_handler; > + //uio->mmap = dfl_uio_mmap; ??? I don't understand what this patch is trying to show... thanks, greg k-h
