> Subject: Re: [RFC] fpga: dfl: a prototype uio driver > > On Sun, Dec 06, 2020 at 01:55:54PM -0800, t...@redhat.com wrote: > > From: Tom Rix <t...@redhat.com> > > > > >From [PATCH 0/2] UIO support for dfl devices > > https://lore.kernel.org/linux-fpga/1602828151-24784-1-git-send-email- > yilun...@intel.com/ > > > > 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. > > Hi Tom: > > Thanks for the idea and detailed illustrate with the patch. I see it > abandons the driver_override and expose all the DFL devices to userspace > by UIO. I'd like to see if we could get some more comments on it.
This allows concurrent access from both userspace and kernel space driver to the same feature device? conflicts? Hao > > Thanks, > Yilun > > > > > Signed-off-by: Tom Rix <t...@redhat.com> > > --- > > 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; > > +} > > + > > +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; > > +} > > + > > +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; > > + uio->open = dfl_uio_open; > > + uio->release = dfl_uio_release; > > + uio->irqcontrol = dfl_uio_irqcontrol; > > + > > + ret = uio_register_device(&feature->dev->dev, uio); > > + if (ret) > > + goto err_register; > > + > > +exit: > > + return ret; > > +err_register: > > + kfree(uio->name); > > + goto exit; > > +} > > +EXPORT_SYMBOL_GPL(dfl_uio_add); > > + > > +int dfl_uio_remove(struct dfl_feature *feature) > > +{ > > + uio_unregister_device(&feature->uio); > > + kfree(feature->uio.name); > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(dfl_uio_remove); > > + > > diff --git a/drivers/fpga/dfl.c b/drivers/fpga/dfl.c > > index 1305be48037d..af2cd3d1b5f6 100644 > > --- a/drivers/fpga/dfl.c > > +++ b/drivers/fpga/dfl.c > > @@ -603,6 +603,7 @@ static int dfl_feature_instance_init(struct > platform_device *pdev, > > } > > > > feature->ops = drv->ops; > > + mutex_init(&feature->lock); > > > > return ret; > > } > > @@ -663,10 +664,51 @@ exit: > > } > > EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_init); > > > > +int dfl_fpga_dev_feature_init_uio(struct platform_device *pdev, int > dfh_type) { > > + struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev- > >dev); > > + struct dfl_feature *feature; > > + int ret; > > + > > + dfl_fpga_dev_for_each_feature(pdata, feature) { > > + if (dfh_type == DFH_TYPE_FIU) { > > + if (feature->id == FEATURE_ID_FIU_HEADER || > > + feature->id == FEATURE_ID_AFU) > > + continue; > > + > > + ret = dfl_uio_add(feature); > > + if (ret) > > + goto exit; > > + } > > + } > > + > > + return 0; > > +exit: > > + dfl_fpga_dev_feature_uinit_uio(pdev, dfh_type); > > + return ret; > > +} > > +EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_init_uio); > > + > > +int dfl_fpga_dev_feature_uinit_uio(struct platform_device *pdev, int > dfh_type) { > > + struct dfl_feature_platform_data *pdata = dev_get_platdata(&pdev- > >dev); > > + struct dfl_feature *feature; > > + int ret = 0; > > + > > + dfl_fpga_dev_for_each_feature(pdata, feature) { > > + if (dfh_type == DFH_TYPE_FIU) { > > + if (feature->id == FEATURE_ID_FIU_HEADER || > > + feature->id == FEATURE_ID_AFU) > > + continue; > > + > > + ret |= dfl_uio_remove(feature); > > + } > > + } > > + return ret; > > +} > > +EXPORT_SYMBOL_GPL(dfl_fpga_dev_feature_uinit_uio); > > + > > static void dfl_chardev_uinit(void) > > { > > int i; > > - > > for (i = 0; i < DFL_FPGA_DEVT_MAX; i++) > > if (MAJOR(dfl_chrdevs[i].devt)) { > > unregister_chrdev_region(dfl_chrdevs[i].devt, > > diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h > > index a85d1cd7a130..fde0fc902d4d 100644 > > --- a/drivers/fpga/dfl.h > > +++ b/drivers/fpga/dfl.h > > @@ -26,6 +26,7 @@ > > #include <linux/platform_device.h> > > #include <linux/slab.h> > > #include <linux/uuid.h> > > +#include <linux/uio_driver.h> > > #include <linux/fpga/fpga-region.h> > > > > /* maximum supported number of ports */ > > @@ -232,6 +233,7 @@ struct dfl_feature_irq_ctx { > > * struct dfl_feature - sub feature of the feature devices > > * > > * @dev: ptr to pdev of the feature device which has the sub feature. > > + * @uio: uio interface for feature. > > * @id: sub feature id. > > * @index: unique identifier for an sub feature within the feature device. > > * It is possible that multiply sub features with same feature id are > > @@ -248,6 +250,8 @@ struct dfl_feature_irq_ctx { > > */ > > struct dfl_feature { > > struct platform_device *dev; > > + struct uio_info uio; > > + struct mutex lock; /* serialize dev and uio */ > > u64 id; > > int index; > > int resource_index; > > @@ -360,6 +364,11 @@ void dfl_fpga_dev_feature_uinit(struct > platform_device *pdev); > > int dfl_fpga_dev_feature_init(struct platform_device *pdev, > > struct dfl_feature_driver *feature_drvs); > > > > +int dfl_fpga_dev_feature_init_uio(struct platform_device *pdev, int > dfh_type); > > +int dfl_fpga_dev_feature_uinit_uio(struct platform_device *pdev, int > dfh_type); > > +int dfl_uio_add(struct dfl_feature *feature); > > +int dfl_uio_remove(struct dfl_feature *feature); > > + > > int dfl_fpga_dev_ops_register(struct platform_device *pdev, > > const struct file_operations *fops, > > struct module *owner); > > diff --git a/uio.c b/uio.c > > new file mode 100644 > > index 000000000000..50210aab4822 > > --- /dev/null > > +++ b/uio.c > > @@ -0,0 +1,56 @@ > > +#include <stdlib.h> > > +#include <stdio.h> > > +#include <unistd.h> > > +#include <sys/mman.h> > > +#include <sys/types.h> > > +#include <sys/stat.h> > > +#include <fcntl.h> > > +#include <errno.h> > > +#include <stdint.h> > > + > > +int main() > > +{ > > + int fd; > > + uint64_t *ptr; > > + unsigned page_size=sysconf(_SC_PAGESIZE); > > + struct stat sb; > > + > > + /* > > + * this is fid 1, thermal mgt > > + * ex/ > > + * # cat /sys/class/hwmon/hwmon3/temp1_input > > + * 39000 > > + */ > > + fd = open("/dev/uio0", O_RDONLY|O_SYNC); > > + if (fd < 0) { > > + perror("uio open:"); > > + return errno; > > + } > > + > > + ptr = (uint64_t *) mmap(NULL, page_size, PROT_READ, MAP_SHARED, > fd, 0); > > + if (!ptr) { > > + perror("uio mmap:"); > > + } else { > > + > > + /* from dfl-fme-main.c : > > + * > > + * #define FME_THERM_RDSENSOR_FMT1 0x10 > > + * #define FPGA_TEMPERATURE GENMASK_ULL(6, 0) > > + * > > + * case hwmon_temp_input: > > + * v = readq(feature->ioaddr + > FME_THERM_RDSENSOR_FMT1); > > + * *val = (long)(FIELD_GET(FPGA_TEMPERATURE, v) * 1000); > > + * break; > > + */ > > + uint64_t v = ptr[2]; > > + v &= (1 << 6) -1; > > + v *= 1000; > > + printf("Temperature %d\n", v); > > + > > + munmap(ptr, page_size); > > + } > > + if (close(fd)) > > + perror("uio close:"); > > + > > + return errno; > > +} > > -- > > 2.18.4