Re: uio: uio_pci_generic: add missing memory mappings

From: Greg KH
Date: Sat Apr 24 2021 - 02:55:44 EST

On Fri, Apr 23, 2021 at 12:10:29PM -0400, firas ashkar wrote:
> Hi,
> pls find attached a trivial but necessary patch, this change is based on [drivers/uio/uio_pdrv_genirq.c],
> the patch was tested on following hardware: MiniPCIE AltaData ARNIC-429 module on imx8qm-apalis-ixora-v1.2
>
> --
> Firas Ashkar
> Developpeur Système Embarqué
>
> savoirfairelinux.com | Montréal, Québec
>
> Tél.: +1 514 276 5468 ext. 118
> --------------------------------------
>
> >From 0c83bbc8bbf6c45efc52f6d30b8302a5d9075198 Mon Sep 17 00:00:00 2001
> From: Firas Ashkar <firas.ashkar@xxxxxxxxxxxxxxxxxxxx>
> Date: Fri, 23 Apr 2021 10:38:28 -0400
> Subject: [PATCH 1/1] uio: uio_pci_generic: add memory mappings
>
> import memory resources from underlaying pci device, thus allowing
> userspace applications to memory map those resources.
> ---
> drivers/uio/uio_pci_generic.c | 52 +++++++++++++++++++++++++++++------
> 1 file changed, 43 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/uio/uio_pci_generic.c
> b/drivers/uio/uio_pci_generic.c
> index c7d681fef198..809eca95b5bb 100644
> --- a/drivers/uio/uio_pci_generic.c
> +++ b/drivers/uio/uio_pci_generic.c
> @@ -24,9 +24,9 @@
> #include <linux/slab.h>
> #include <linux/uio_driver.h>
>
> -#define DRIVER_VERSION "0.01.0"
> -#define DRIVER_AUTHOR "Michael S. Tsirkin <mst@xxxxxxxxxx>"
> -#define DRIVER_DESC "Generic UIO driver for PCI 2.3 devices"
> +#define DRIVER_VERSION "0.01.0"
> +#define DRIVER_AUTHOR "Michael S. Tsirkin <mst@xxxxxxxxxx>"
> +#define DRIVER_DESC "Generic UIO driver for PCI 2.3 devices"
>
> struct uio_pci_generic_dev {
> struct uio_info info;
> @@ -56,7 +56,8 @@ static int release(struct uio_info *info, struct
> inode *inode)
> }
>
> /* Interrupt handler. Read/modify/write the command register to
> disable
> - * the interrupt. */
> + * the interrupt.
> + */
> static irqreturn_t irqhandler(int irq, struct uio_info *info)
> {
> struct uio_pci_generic_dev *gdev =
> to_uio_pci_generic_dev(info);
> @@ -68,11 +69,12 @@ static irqreturn_t irqhandler(int irq, struct
> uio_info *info)
> return IRQ_HANDLED;
> }
>
> -static int probe(struct pci_dev *pdev,
> - const struct pci_device_id *id)
> +static int probe(struct pci_dev *pdev, const struct pci_device_id *id)
> {
> struct uio_pci_generic_dev *gdev;
> + struct uio_mem *uiomem;
> int err;
> + int i;
>
> err = pcim_enable_device(pdev);
> if (err) {
> @@ -84,7 +86,8 @@ static int probe(struct pci_dev *pdev,
> if (pdev->irq && !pci_intx_mask_supported(pdev))
> return -ENOMEM;
>
> - gdev = devm_kzalloc(&pdev->dev, sizeof(struct
> uio_pci_generic_dev), GFP_KERNEL);
> + gdev = devm_kzalloc(&pdev->dev, sizeof(struct
> uio_pci_generic_dev),
> + GFP_KERNEL);
> if (!gdev)
> return -ENOMEM;
>
> @@ -97,8 +100,39 @@ static int probe(struct pci_dev *pdev,
> gdev->info.irq_flags = IRQF_SHARED;
> gdev->info.handler = irqhandler;
> } else {
> - dev_warn(&pdev->dev, "No IRQ assigned to device: "
> - "no support for interrupts?\n");
> + dev_warn(
> + &pdev->dev,
> + "No IRQ assigned to device: no support for
> interrupts?\n");
> + }
> +
> + uiomem = &gdev->info.mem[0];
> + for (i = 0; i < MAX_UIO_MAPS; ++i) {
> + struct resource *r = &pdev->resource[i];
> +
> + if (r->flags != (IORESOURCE_SIZEALIGN |
> IORESOURCE_MEM))
> + continue;
> +
> + if (uiomem >= &gdev->info.mem[MAX_UIO_MAPS]) {
> + dev_warn(
> + &pdev->dev,
> + "device has more than " __stringify(
> + MAX_UIO_MAPS) " I/O memory
> resources.\n");
> + break;
> + }
> +
> + uiomem->memtype = UIO_MEM_PHYS;
> + uiomem->addr = r->start & PAGE_MASK;
> + uiomem->offs = r->start & ~PAGE_MASK;
> + uiomem->size =
> + (uiomem->offs + resource_size(r) + PAGE_SIZE -
> 1) &
> + PAGE_MASK;
> + uiomem->name = r->name;
> + ++uiomem;
> + }
> +
> + while (uiomem < &gdev->info.mem[MAX_UIO_MAPS]) {
> + uiomem->size = 0;
> + ++uiomem;
> }
>
> return devm_uio_register_device(&pdev->dev, &gdev->info);
> --
> 2.25.1
>


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