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/ > > 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. Thanks, Yilun > > 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; > +} > + > +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
