[PATCH v3] UIO: Implement a UIO interface for the SMX Cryptengine - Kernel

This is a discussion on [PATCH v3] UIO: Implement a UIO interface for the SMX Cryptengine - Kernel ; This patch implements a UIO interface for the SMX Cryptengine. The Cryptengine found on the Nias Digital SMX board is best suited for a UIO interface. It is not wired in to the cryptographic API as the engine handles it's ...

+ Reply to Thread
Results 1 to 4 of 4

Thread: [PATCH v3] UIO: Implement a UIO interface for the SMX Cryptengine

  1. [PATCH v3] UIO: Implement a UIO interface for the SMX Cryptengine

    This patch implements a UIO interface for the SMX Cryptengine.

    The Cryptengine found on the Nias Digital SMX board is best suited
    for a UIO interface. It is not wired in to the cryptographic API
    as the engine handles it's own keys, algorithms, everything. All
    that we know about is that if there's room in the buffer, you can
    write data to it and when there's data ready, you read it out again.

    There isn't necessarily even any direct correlation between data
    going in and data coming out again, the engine may consume or
    generate data all on its own.

    This driver is for proprietary hardware but we're always told to
    submit the drivers anyway; here you are. :-)

    This is version 2 of this patch and addresses all issues raised by
    Hans-Jürgen Koch and Paul Mundt in their reviews.

    Signed-off-by: Ben Nizette
    ---
    Apologies for the confusion around this patch, I didn't mean to give the
    impression that I'd ignored Paul; I am of course grateful for his review
    and bug catch. I received the review just a minute after sending out
    the last version, made the change locally but didn't immediately resend.
    I'll know better next time.

    diff --git a/MAINTAINERS b/MAINTAINERS
    index 2cdb591..480fd44 100644
    --- a/MAINTAINERS
    +++ b/MAINTAINERS
    @@ -3554,6 +3554,11 @@ M: mhoffman@lightlink.com
    L: lm-sensors@lm-sensors.org
    S: Maintained

    +SMX UIO Interface
    +P: Ben Nizette
    +M: bn@niasdigital.com
    +S: Maintained
    +
    SOFTMAC LAYER (IEEE 802.11)
    P: Daniel Drake
    M: dsd@gentoo.org
    diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
    index b778ed7..f57b347 100644
    --- a/drivers/uio/Kconfig
    +++ b/drivers/uio/Kconfig
    @@ -26,4 +26,16 @@ config UIO_CIF
    To compile this driver as a module, choose M here: the module
    will be called uio_cif.

    +config UIO_SMX
    + tristate "SMX cryptengine UIO interface"
    + depends on UIO
    + default n
    + help
    + Userspace IO interface to the Cryptography engine found on the
    + Nias Digital SMX boards. These will be available from Q4 2008
    + from http://www.niasdigital.com. The userspace part of this
    + driver will be released under the GPL at the same time as the
    + hardware and will be able to be downloaded from the same site.
    +
    + If you compile this as a module, it will be called uio_smx.
    endmenu
    diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
    index 7fecfb4..18c4566 100644
    --- a/drivers/uio/Makefile
    +++ b/drivers/uio/Makefile
    @@ -1,2 +1,3 @@
    obj-$(CONFIG_UIO) += uio.o
    obj-$(CONFIG_UIO_CIF) += uio_cif.o
    +obj-$(CONFIG_UIO_SMX) += uio_smx.o
    diff --git a/drivers/uio/uio_smx.c b/drivers/uio/uio_smx.c
    new file mode 100644
    index 0000000..fda8b8b
    --- /dev/null
    +++ b/drivers/uio/uio_smx.c
    @@ -0,0 +1,118 @@
    +/*
    + * UIO SMX Cryptengine driver.
    + *
    + * (C) 2008 Nias Digital P/L
    + *
    + * This program is free software; you can redistribute it and/or modify
    + * it under the terms of the GNU General Public License version 2 as
    + * published by the Free Software Foundation.
    + *
    + */
    +
    +#include
    +#include
    +#include
    +#include
    +
    +#include
    +
    +#define SMX_CSR 0x00000000
    +#define SMX_EnD 0x00000001
    +#define SMX_RUN 0x00000002
    +#define SMX_DRDY 0x00000004
    +#define SMX_ERR 0x00000008
    +
    +static irqreturn_t smx_handler(int irq, struct uio_info *dev_info)
    +{
    + void __iomem *csr = dev_info->mem[0].internal_addr + SMX_CSR;
    +
    + u32 status = ioread32(csr);
    +
    + if (!(csr & SMX_DRDY))
    + return IRQ_NONE;
    +
    + /* Disable interrupt */
    + iowrite32(status & ~SMX_DRDY, csr);
    + return IRQ_HANDLED;
    +}
    +
    +static int __devinit smx_ce_probe(struct platform_device *dev)
    +{
    + struct uio_info *info;
    + struct resource *regs;
    +
    + info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
    + if (!info)
    + return -ENOMEM;
    +
    + regs = platform_get_resource(dev, IORESOURCE_MEM, 0);
    + if (!regs)
    + goto out_free;
    +
    + info->mem[0].addr = regs->start;
    + if (!info->mem[0].addr)
    + goto out_free;
    +
    + info->mem[0].size = regs->end - regs->start + 1;
    + info->mem[0].internal_addr = ioremap(regs->start, info->mem[0].size);
    + if (!info->mem[0].internal_addr)
    + goto out_free;
    +
    + info->mem[0].memtype = UIO_MEM_PHYS;
    +
    + info->name = "smx-ce";
    + info->version = "0.03";
    + info->irq = platform_get_irq(dev, 0);
    + info->irq_flags = IRQF_SHARED;
    + info->handler = smx_handler;
    +
    + platform_set_drvdata(dev, info);
    +
    + if (uio_register_device(&dev->dev, info))
    + goto out_unmap;
    +
    + return 0;
    +out_unmap:
    + iounmap(info->mem[0].internal_addr);
    +out_free:
    + kfree(info);
    +
    + return -ENODEV;
    +}
    +
    +static int __devexit smx_ce_remove(struct platform_device *dev)
    +{
    + struct uio_info *info = platform_get_drvdata(dev);
    +
    + uio_unregister_device(info);
    + platform_set_drvdata(dev, NULL);
    + iounmap(info->mem[0].internal_addr);
    +
    + kfree(info);
    +
    + return 0;
    +}
    +
    +static struct platform_driver smx_ce_driver = {
    + .probe = smx_ce_probe,
    + .remove = __devexit_p(smx_ce_remove),
    + .driver = {
    + .name = "smx-ce",
    + .owner = THIS_MODULE,
    + },
    +};
    +
    +static int __init smx_ce_init_module(void)
    +{
    + return platform_driver_register(&smx_ce_driver);
    +}
    +module_init(smx_ce_init_module);
    +
    +static void __exit smx_ce_exit_module(void)
    +{
    + platform_driver_unregister(&smx_ce_driver);
    +}
    +module_exit(smx_ce_exit_module);
    +
    +MODULE_LICENSE("GPL v2");
    +MODULE_AUTHOR("Ben Nizette ");


    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

  2. Re: [PATCH v3] UIO: Implement a UIO interface for the SMX Cryptengine

    On Thu, Mar 13, 2008 at 08:35:40PM +1100, Ben Nizette wrote:
    > diff --git a/drivers/uio/uio_smx.c b/drivers/uio/uio_smx.c
    > new file mode 100644
    > index 0000000..fda8b8b
    > --- /dev/null
    > +++ b/drivers/uio/uio_smx.c
    > @@ -0,0 +1,118 @@
    > +/*
    > + * UIO SMX Cryptengine driver.
    > + *
    > + * (C) 2008 Nias Digital P/L
    > + *
    > + * This program is free software; you can redistribute it and/or modify
    > + * it under the terms of the GNU General Public License version 2 as
    > + * published by the Free Software Foundation.
    > + *
    > + */
    > +
    > +#include
    > +#include
    > +#include
    > +#include
    > +
    > +#include
    > +

    linux/io.h is preferable here.

    > +static int __devinit smx_ce_probe(struct platform_device *dev)
    > +{
    > + struct uio_info *info;
    > + struct resource *regs;
    > +
    > + info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
    > + if (!info)
    > + return -ENOMEM;
    > +
    > + regs = platform_get_resource(dev, IORESOURCE_MEM, 0);
    > + if (!regs)
    > + goto out_free;
    > +
    > + info->mem[0].addr = regs->start;
    > + if (!info->mem[0].addr)
    > + goto out_free;
    > +
    > + info->mem[0].size = regs->end - regs->start + 1;
    > + info->mem[0].internal_addr = ioremap(regs->start, info->mem[0].size);
    > + if (!info->mem[0].internal_addr)
    > + goto out_free;
    > +
    > + info->mem[0].memtype = UIO_MEM_PHYS;
    > +
    > + info->name = "smx-ce";
    > + info->version = "0.03";


    You may as well use DRV_NAME and DRV_VERSION, then you can toss that over
    to MODULE_VERSION() if you're so inclined. It's generally nice to keep
    modinfo happy.

    > + info->irq = platform_get_irq(dev, 0);
    > + info->irq_flags = IRQF_SHARED;
    > + info->handler = smx_handler;
    > +

    platform_get_irq() can fail, which you don't presently handle (though I
    guess uio_register_device() will error out if you hand off -ENXIO as your
    IRQ anyways, so it's not technically an issue). That's a pretty minor
    issue, though, but might be something you wish to fix up if you are
    planning on using this as an example driver for others.

    > + platform_set_drvdata(dev, info);
    > +
    > + if (uio_register_device(&dev->dev, info))
    > + goto out_unmap;
    > +
    > + return 0;
    > +out_unmap:
    > + iounmap(info->mem[0].internal_addr);
    > +out_free:
    > + kfree(info);
    > +
    > + return -ENODEV;
    > +}
    > +

    Your error paths are also pretty quiet. A dev_err() or so in the few
    failure cases you do have might not be a terrible idea.

    uio_register_device() also has quite a few different error cases, so it's
    at least worth preserving the error value and returning that back,
    rather than always returning -ENODEV.
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

  3. Re: [PATCH v3] UIO: Implement a UIO interface for the SMX Cryptengine

    Am Thu, 13 Mar 2008 20:35:40 +1100
    schrieb Ben Nizette :

    Ben,
    sorry, but your code doesn't compile. See below.

    Thanks,
    Hans

    > This patch implements a UIO interface for the SMX Cryptengine.
    >
    > The Cryptengine found on the Nias Digital SMX board is best suited
    > for a UIO interface. It is not wired in to the cryptographic API
    > as the engine handles it's own keys, algorithms, everything. All
    > that we know about is that if there's room in the buffer, you can
    > write data to it and when there's data ready, you read it out again.
    >
    > There isn't necessarily even any direct correlation between data
    > going in and data coming out again, the engine may consume or
    > generate data all on its own.
    >
    > This driver is for proprietary hardware but we're always told to
    > submit the drivers anyway; here you are. :-)
    >
    > This is version 2 of this patch and addresses all issues raised by
    > Hans-Jürgen Koch and Paul Mundt in their reviews.
    >
    > Signed-off-by: Ben Nizette
    > ---
    > Apologies for the confusion around this patch, I didn't mean to give the
    > impression that I'd ignored Paul; I am of course grateful for his review
    > and bug catch. I received the review just a minute after sending out
    > the last version, made the change locally but didn't immediately resend.
    > I'll know better next time.
    >
    > diff --git a/MAINTAINERS b/MAINTAINERS
    > index 2cdb591..480fd44 100644
    > --- a/MAINTAINERS
    > +++ b/MAINTAINERS
    > @@ -3554,6 +3554,11 @@ M: mhoffman@lightlink.com
    > L: lm-sensors@lm-sensors.org
    > S: Maintained
    >
    > +SMX UIO Interface
    > +P: Ben Nizette
    > +M: bn@niasdigital.com
    > +S: Maintained
    > +
    > SOFTMAC LAYER (IEEE 802.11)
    > P: Daniel Drake
    > M: dsd@gentoo.org
    > diff --git a/drivers/uio/Kconfig b/drivers/uio/Kconfig
    > index b778ed7..f57b347 100644
    > --- a/drivers/uio/Kconfig
    > +++ b/drivers/uio/Kconfig
    > @@ -26,4 +26,16 @@ config UIO_CIF
    > To compile this driver as a module, choose M here: the module
    > will be called uio_cif.
    >
    > +config UIO_SMX
    > + tristate "SMX cryptengine UIO interface"
    > + depends on UIO
    > + default n
    > + help
    > + Userspace IO interface to the Cryptography engine found on the
    > + Nias Digital SMX boards. These will be available from Q4 2008
    > + from http://www.niasdigital.com. The userspace part of this
    > + driver will be released under the GPL at the same time as the
    > + hardware and will be able to be downloaded from the same site.
    > +
    > + If you compile this as a module, it will be called uio_smx.
    > endmenu
    > diff --git a/drivers/uio/Makefile b/drivers/uio/Makefile
    > index 7fecfb4..18c4566 100644
    > --- a/drivers/uio/Makefile
    > +++ b/drivers/uio/Makefile
    > @@ -1,2 +1,3 @@
    > obj-$(CONFIG_UIO) += uio.o
    > obj-$(CONFIG_UIO_CIF) += uio_cif.o
    > +obj-$(CONFIG_UIO_SMX) += uio_smx.o
    > diff --git a/drivers/uio/uio_smx.c b/drivers/uio/uio_smx.c
    > new file mode 100644
    > index 0000000..fda8b8b
    > --- /dev/null
    > +++ b/drivers/uio/uio_smx.c
    > @@ -0,0 +1,118 @@
    > +/*
    > + * UIO SMX Cryptengine driver.
    > + *
    > + * (C) 2008 Nias Digital P/L
    > + *
    > + * This program is free software; you can redistribute it and/or modify
    > + * it under the terms of the GNU General Public License version 2 as
    > + * published by the Free Software Foundation.
    > + *
    > + */
    > +
    > +#include
    > +#include
    > +#include
    > +#include
    > +
    > +#include
    > +
    > +#define SMX_CSR 0x00000000
    > +#define SMX_EnD 0x00000001
    > +#define SMX_RUN 0x00000002
    > +#define SMX_DRDY 0x00000004
    > +#define SMX_ERR 0x00000008
    > +
    > +static irqreturn_t smx_handler(int irq, struct uio_info *dev_info)
    > +{
    > + void __iomem *csr = dev_info->mem[0].internal_addr + SMX_CSR;
    > +
    > + u32 status = ioread32(csr);
    > +
    > + if (!(csr & SMX_DRDY))


    This doesn't compile.

    > + return IRQ_NONE;
    > +
    > + /* Disable interrupt */
    > + iowrite32(status & ~SMX_DRDY, csr);
    > + return IRQ_HANDLED;
    > +}
    > +
    > +static int __devinit smx_ce_probe(struct platform_device *dev)
    > +{
    > + struct uio_info *info;
    > + struct resource *regs;
    > +
    > + info = kzalloc(sizeof(struct uio_info), GFP_KERNEL);
    > + if (!info)
    > + return -ENOMEM;
    > +
    > + regs = platform_get_resource(dev, IORESOURCE_MEM, 0);
    > + if (!regs)
    > + goto out_free;
    > +
    > + info->mem[0].addr = regs->start;
    > + if (!info->mem[0].addr)
    > + goto out_free;
    > +
    > + info->mem[0].size = regs->end - regs->start + 1;
    > + info->mem[0].internal_addr = ioremap(regs->start, info->mem[0].size);
    > + if (!info->mem[0].internal_addr)
    > + goto out_free;
    > +
    > + info->mem[0].memtype = UIO_MEM_PHYS;
    > +
    > + info->name = "smx-ce";
    > + info->version = "0.03";
    > + info->irq = platform_get_irq(dev, 0);
    > + info->irq_flags = IRQF_SHARED;
    > + info->handler = smx_handler;
    > +
    > + platform_set_drvdata(dev, info);
    > +
    > + if (uio_register_device(&dev->dev, info))
    > + goto out_unmap;
    > +
    > + return 0;
    > +out_unmap:
    > + iounmap(info->mem[0].internal_addr);
    > +out_free:
    > + kfree(info);
    > +
    > + return -ENODEV;
    > +}
    > +
    > +static int __devexit smx_ce_remove(struct platform_device *dev)
    > +{
    > + struct uio_info *info = platform_get_drvdata(dev);
    > +
    > + uio_unregister_device(info);
    > + platform_set_drvdata(dev, NULL);
    > + iounmap(info->mem[0].internal_addr);
    > +
    > + kfree(info);
    > +
    > + return 0;
    > +}
    > +
    > +static struct platform_driver smx_ce_driver = {
    > + .probe = smx_ce_probe,
    > + .remove = __devexit_p(smx_ce_remove),
    > + .driver = {
    > + .name = "smx-ce",
    > + .owner = THIS_MODULE,
    > + },
    > +};
    > +
    > +static int __init smx_ce_init_module(void)
    > +{
    > + return platform_driver_register(&smx_ce_driver);
    > +}
    > +module_init(smx_ce_init_module);
    > +
    > +static void __exit smx_ce_exit_module(void)
    > +{
    > + platform_driver_unregister(&smx_ce_driver);
    > +}
    > +module_exit(smx_ce_exit_module);
    > +
    > +MODULE_LICENSE("GPL v2");
    > +MODULE_AUTHOR("Ben Nizette ");
    >

    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

  4. Re: [PATCH v3] UIO: Implement a UIO interface for the SMX Cryptengine

    Am Thu, 13 Mar 2008 19:06:55 +0900
    schrieb Paul Mundt :

    > > +
    > > + info->name = "smx-ce";
    > > + info->version = "0.03";

    >
    > You may as well use DRV_NAME and DRV_VERSION, then you can toss that over
    > to MODULE_VERSION() if you're so inclined. It's generally nice to keep
    > modinfo happy.


    UIO name and version are intentionally independent of module name and
    version. It's meant to be an information for the userspace part of the driver
    and should be set to values that are meaningful for it.

    >
    > > + info->irq = platform_get_irq(dev, 0);
    > > + info->irq_flags = IRQF_SHARED;
    > > + info->handler = smx_handler;
    > > +

    > platform_get_irq() can fail, which you don't presently handle (though I
    > guess uio_register_device() will error out if you hand off -ENXIO as your
    > IRQ anyways, so it's not technically an issue). That's a pretty minor
    > issue, though, but might be something you wish to fix up if you are
    > planning on using this as an example driver for others.


    uio_register_device() will silently not register an interrupt if the number
    is negative. This allows us to register a driver without interrupts. Hmm.
    Maybe we should explicitly check for UIO_IRQ_NONE there and fail if a
    different negative irq is passed in. Thanks for pointing this out.

    But I agree, Ben should check if platform_get_irq() failed.

    >
    > > + platform_set_drvdata(dev, info);
    > > +
    > > + if (uio_register_device(&dev->dev, info))
    > > + goto out_unmap;
    > > +
    > > + return 0;
    > > +out_unmap:
    > > + iounmap(info->mem[0].internal_addr);
    > > +out_free:
    > > + kfree(info);
    > > +
    > > + return -ENODEV;
    > > +}
    > > +

    > Your error paths are also pretty quiet. A dev_err() or so in the few
    > failure cases you do have might not be a terrible idea.


    I agree.

    >
    > uio_register_device() also has quite a few different error cases, so it's
    > at least worth preserving the error value and returning that back,
    > rather than always returning -ENODEV.


    Right. Maybe we should make uio_register_device a bit more verbose, too.

    Thanks for your detailed review!

    Hans
    --
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

+ Reply to Thread