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In-Reply-To: <20210324183610.4574-2-maciej.kwapulinski@linux.intel.com>
From:   Andy Shevchenko <andy.shevchenko@gmail.com>
Date:   Wed, 24 Mar 2021 21:30:49 +0200
Message-ID: <CAHp75Vf54GNsw_xWqiOhZx5aHHnQ_-wUWugQ8w9vJPRheLxHFA@mail.gmail.com>
Subject: Re: [PATCH v2 01/13] intel_gna: add driver module
To:     Maciej Kwapulinski <maciej.kwapulinski@linux.intel.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Jonathan Corbet <corbet@lwn.net>,
        Derek Kiernan <derek.kiernan@xilinx.com>,
        Dragan Cvetic <dragan.cvetic@xilinx.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Linux Documentation List <linux-doc@vger.kernel.org>,
        Tomasz Jankowski <tomasz1.jankowski@intel.com>,
        Savo Novakovic <savox.novakovic@intel.com>,
        Jianxun Zhang <jianxun.zhang@linux.intel.com>
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Precedence: bulk

On Wed, Mar 24, 2021 at 8:38 PM Maciej Kwapulinski
<maciej.kwapulinski@linux.intel.com> wrote:
>
> From: Tomasz Jankowski <tomasz1.jankowski@intel.com>
>
> Add a new PCI driver for Intel(R) Gaussian & Neural Accelerator
> with basic support like module loading and unloading. The full
> function of the driver will be added by further changes.
>
> Signed-off-by: Tomasz Jankowski <tomasz1.jankowski@intel.com>
> Tested-by: Savo Novakovic <savox.novakovic@intel.com>
> Co-developed-by: Jianxun Zhang <jianxun.zhang@linux.intel.com>
> Signed-off-by: Jianxun Zhang <jianxun.zhang@linux.intel.com>
> Co-developed-by: Maciej Kwapulinski <maciej.kwapulinski@linux.intel.com>
> Signed-off-by: Maciej Kwapulinski <maciej.kwapulinski@linux.intel.com>
> ---
>  Documentation/misc-devices/index.rst          |   1 +
>  Documentation/misc-devices/intel/gna.rst      |  48 ++++++
>  .../userspace-api/ioctl/ioctl-number.rst      |   1 +
>  MAINTAINERS                                   |   7 +
>  drivers/misc/Kconfig                          |   1 +
>  drivers/misc/Makefile                         |   1 +
>  drivers/misc/intel/gna/Kbuild                 |   5 +
>  drivers/misc/intel/gna/Kconfig                |  13 ++
>  drivers/misc/intel/gna/gna_device.c           |  74 +++++++++
>  drivers/misc/intel/gna/gna_device.h           |  36 ++++
>  drivers/misc/intel/gna/gna_driver.c           |  39 +++++
>  drivers/misc/intel/gna/gna_driver.h           |  15 ++

What is the point now to have gna/gna_, I guess the latter should go?

>  include/uapi/misc/intel/gna.h                 | 155 ++++++++++++++++++
>  13 files changed, 396 insertions(+)
>  create mode 100644 Documentation/misc-devices/intel/gna.rst
>  create mode 100644 drivers/misc/intel/gna/Kbuild
>  create mode 100644 drivers/misc/intel/gna/Kconfig
>  create mode 100644 drivers/misc/intel/gna/gna_device.c
>  create mode 100644 drivers/misc/intel/gna/gna_device.h
>  create mode 100644 drivers/misc/intel/gna/gna_driver.c
>  create mode 100644 drivers/misc/intel/gna/gna_driver.h
>  create mode 100644 include/uapi/misc/intel/gna.h
>
> diff --git a/Documentation/misc-devices/index.rst b/Documentation/misc-devices/index.rst
> index 64420b3314fe..1b187ee121b0 100644
> --- a/Documentation/misc-devices/index.rst
> +++ b/Documentation/misc-devices/index.rst
> @@ -19,6 +19,7 @@ fit into other categories.
>     bh1770glc
>     eeprom
>     c2port
> +   intel/gna

Shouldn't it preserve ordering?

>     ibmvmc
>     ics932s401
>     isl29003
> diff --git a/Documentation/misc-devices/intel/gna.rst b/Documentation/misc-devices/intel/gna.rst
> new file mode 100644
> index 000000000000..9baeec5ceb5c
> --- /dev/null
> +++ b/Documentation/misc-devices/intel/gna.rst
> @@ -0,0 +1,48 @@
> +.. SPDX-License-Identifier: GPL-2.0-only
> +
> +=====================================================
> +Intel(R) Gaussian & Neural Accelerator (Intel(R) GNA)
> +=====================================================
> +
> +Acronyms
> +--------
> +GNA    - Gaussian & Neural Accelerator
> +GMM    - Gaussian Mixer Model
> +CNN    - Convolutional Neural Network
> +RNN    - Recurrent Neural Networks
> +DNN    - Deep Neural Networks
> +
> +Introduction
> +------------
> +The Intel(R) GNA is an internal PCI fixed device available on several Intel platforms/SoCs.
> +Feature set depends on the Intel chipset SKU.
> +
> +Intel(R) GNA provides hardware accelerated computation for GMMs and Neural Networks.
> +It supports several layer types: affine, recurrent, and convolutional among others.
> +Hardware also provides helper layer types for copying and transposing matrices.
> +
> +Linux Driver
> +------------
> +The driver also registers a character device to expose file operations via dev node.
> +
> +The driver probes/removes PCI device, implements file operations, handles runtime

a PCI device


> +power management, and interacts with hardware through MMIO registers.
> +
> +Multiple processes can independently file many requests to the driver. These requests are
> +processed in a FIFO manner. The hardware can process one request at a time by using a FIFO
> +queue.
> +
> +IOCTL
> +-----
> +Intel(R) GNA driver controls the device through IOCTL interfaces.
> +Following IOCTL commands are supported:
> +
> +GNA_IOCTL_PARAM_GET gets driver and device capabilities.
> +
> +GNA_IOCTL_MEMORY_MAP locks user pages and GNA MMU setups for DMA transfer.
> +
> +GNA_IOCTL_MEMORY_UNMAP unlocks user pages and releases GNA MMU structures.
> +
> +GNA_IOCTL_COMPUTE submits a request to the device queue.
> +
> +GNA_IOCTL_WAIT blocks and waits on the submitted request.
> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
> index a4c75a28c839..9ec2b32f656a 100644
> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> @@ -115,6 +115,7 @@ Code  Seq#    Include File                                           Comments
>  'B'   C0-FF  advanced bbus                                           <mailto:maassen@uni-freiburg.de>
>  'C'   all    linux/soundcard.h                                       conflict!
>  'C'   01-2F  linux/capi.h                                            conflict!
> +'C'   01-5F  uapi/misc/intel/gna.h                                   conflict!
>  'C'   F0-FF  drivers/net/wan/cosa.h                                  conflict!
>  'D'   all    arch/s390/include/asm/dasd.h
>  'D'   40-5F  drivers/scsi/dpt/dtpi_ioctl.h
> diff --git a/MAINTAINERS b/MAINTAINERS
> index bfc1b86e3e73..da926aa4523c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8928,6 +8928,13 @@ S:       Maintained
>  F:     Documentation/fb/intelfb.rst
>  F:     drivers/video/fbdev/intelfb/
>
> +INTEL GNA PCI DRIVER
> +M:     Maciej Kwapulinski <maciej.kwapulinski@linux.intel.com>
> +S:     Maintained
> +F:     Documentation/misc-devices/intel/gna.rst
> +F:     drivers/misc/intel/gna/*
> +F:     include/uapi/misc/intel/gna.h
> +
>  INTEL GPIO DRIVERS
>  M:     Andy Shevchenko <andy@kernel.org>
>  L:     linux-gpio@vger.kernel.org
> diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
> index fafa8b0d8099..ce3dc5b9f821 100644
> --- a/drivers/misc/Kconfig
> +++ b/drivers/misc/Kconfig
> @@ -481,4 +481,5 @@ source "drivers/misc/ocxl/Kconfig"
>  source "drivers/misc/cardreader/Kconfig"
>  source "drivers/misc/habanalabs/Kconfig"
>  source "drivers/misc/uacce/Kconfig"
> +source "drivers/misc/intel/gna/Kconfig"
>  endmenu
> diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
> index d23231e73330..5fca2e730d96 100644
> --- a/drivers/misc/Makefile
> +++ b/drivers/misc/Makefile
> @@ -57,3 +57,4 @@ obj-$(CONFIG_HABANA_AI)               += habanalabs/
>  obj-$(CONFIG_UACCE)            += uacce/
>  obj-$(CONFIG_XILINX_SDFEC)     += xilinx_sdfec.o
>  obj-$(CONFIG_HISI_HIKEY_USB)   += hisi_hikey_usb.o
> +obj-$(CONFIG_INTEL_GNA)                += intel/gna/
> diff --git a/drivers/misc/intel/gna/Kbuild b/drivers/misc/intel/gna/Kbuild
> new file mode 100644
> index 000000000000..5d3becc71683
> --- /dev/null
> +++ b/drivers/misc/intel/gna/Kbuild
> @@ -0,0 +1,5 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +
> +intel_gna-y := gna_device.o gna_driver.o
> +
> +obj-$(CONFIG_INTEL_GNA) += intel_gna.o
> diff --git a/drivers/misc/intel/gna/Kconfig b/drivers/misc/intel/gna/Kconfig
> new file mode 100644
> index 000000000000..c3b768a40684
> --- /dev/null
> +++ b/drivers/misc/intel/gna/Kconfig
> @@ -0,0 +1,13 @@
> +#
> +# Intel(R) Gaussian & Neural Accelerator (Intel(R) GNA)
> +#
> +
> +config INTEL_GNA
> +       tristate "Intel(R) Gaussian & Neural Accelerator (Intel(R) GNA)"
> +       depends on X86_64 && PCI

Why 64?

> +       help
> +         This option enables the Intel(R) Gaussian & Neural Accelerator
> +         (Intel(R) GNA) driver: intel_gna.
> +         User space interface is defined in include/uapi/misc/intel/gna.h, while
> +         information about functionality is in
> +         Documentation/misc-devices/intel/gna.rst
> diff --git a/drivers/misc/intel/gna/gna_device.c b/drivers/misc/intel/gna/gna_device.c
> new file mode 100644
> index 000000000000..431113297879
> --- /dev/null
> +++ b/drivers/misc/intel/gna/gna_device.c
> @@ -0,0 +1,74 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +// Copyright(c) 2017-2021 Intel Corporation
> +
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +
> +#include "gna_device.h"
> +#include "gna_driver.h"

> +#define GNA_BAR0               0

Why? Expecting something different?

> +static void gna_dev_init(struct gna_private *gna_priv, struct pci_dev *pcidev,
> +                       const struct pci_device_id *pci_id)
> +{

> +       pci_set_drvdata(pcidev, gna_priv);

You assign this and make it visible before assigning fields. Not good.

> +       gna_priv->parent = &pcidev->dev;
> +       gna_priv->pdev = pcidev;
> +       gna_priv->info = *(struct gna_drv_info *)pci_id->driver_data;
> +       gna_priv->drv_priv = &gna_drv_priv;
> +}

Why is this can't be inlined into ->probe() ?

> +int gna_probe(struct pci_dev *pcidev, const struct pci_device_id *pci_id)
> +{
> +       struct gna_private *gna_priv;
> +       void __iomem *const *iomap;
> +       unsigned long phys_len;
> +       phys_addr_t phys;
> +       int ret;
> +
> +       ret = pcim_enable_device(pcidev);
> +       if (ret) {
> +               dev_err(&pcidev->dev, "pci device can't be enabled\n");
> +               return ret;
> +       }
> +
> +       ret = pcim_iomap_regions(pcidev, 1 << GNA_BAR0, GNA_DV_NAME);
> +       if (ret) {
> +               dev_err(&pcidev->dev, "cannot iomap regions\n");
> +               return ret;
> +       }

> +       phys = pci_resource_start(pcidev, GNA_BAR0);
> +       phys_len = pci_resource_len(pcidev, GNA_BAR0);
> +
> +       dev_info(&pcidev->dev, "physical base address %pap, %lu bytes\n",
> +               &phys, phys_len);

Why is it important?

> +       iomap = pcim_iomap_table(pcidev);

> +       if (!iomap) {
> +               dev_err(&pcidev->dev, "failed to iomap table\n");
> +               return -ENODEV;
> +       }

This conditional is redundant.

> +       gna_priv = devm_kzalloc(&pcidev->dev, sizeof(*gna_priv), GFP_KERNEL);
> +       if (!gna_priv)
> +               return -ENOMEM;
> +
> +       gna_priv->bar0_base = iomap[GNA_BAR0];
> +
> +       dev_dbg(&pcidev->dev, "bar0 memory address: %p\n", gna_priv->bar0_base);
> +
> +       ret = dma_set_mask(&pcidev->dev, DMA_BIT_MASK(64));
> +       if (ret) {
> +               dev_err(&pcidev->dev, "pci_set_dma_mask returned error %d\n", ret);

Typo in the message.

Why not try to fall back to 32 bit mask and support 32-bit builds?

> +               return ret;
> +       }
> +
> +       pci_set_master(pcidev);
> +
> +       gna_dev_init(gna_priv, pcidev, pci_id);
> +
> +       return 0;
> +}
> diff --git a/drivers/misc/intel/gna/gna_device.h b/drivers/misc/intel/gna/gna_device.h
> new file mode 100644
> index 000000000000..d0b47f75f47f
> --- /dev/null
> +++ b/drivers/misc/intel/gna/gna_device.h
> @@ -0,0 +1,36 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/* Copyright(c) 2017-2021 Intel Corporation */
> +
> +#ifndef __GNA_DEVICE_H__
> +#define __GNA_DEVICE_H__
> +
> +#include <linux/types.h>
> +
> +struct gna_driver_private;
> +struct pci_device_id;
> +struct pci_dev;
> +struct device;
> +
> +struct gna_drv_info {
> +       u32 hwid;
> +       u32 num_pagetables;
> +       u32 num_page_entries;
> +       u32 max_layer_count;
> +       u64 max_hw_mem;
> +};
> +
> +struct gna_private {
> +       struct gna_driver_private *drv_priv;

> +       struct pci_dev *pdev;
> +       /* pdev->dev */
> +       struct device *parent;

This is a mess. One struct device is enough.
Comment  doesn't bring any value and is confusing.

> +       /* device related resources */
> +       void __iomem *bar0_base;
> +       struct gna_drv_info info;
> +};

> +int gna_probe(struct pci_dev *dev, const struct pci_device_id *id);

This looks wrong. If you provide ->probe() function for others, it's
probably generalized enough and mustn't be PCI or any other bus
dependent. See below.

> +#endif /* __GNA_DEVICE_H__ */
> diff --git a/drivers/misc/intel/gna/gna_driver.c b/drivers/misc/intel/gna/gna_driver.c
> new file mode 100644
> index 000000000000..f4922a388be7
> --- /dev/null
> +++ b/drivers/misc/intel/gna/gna_driver.c
> @@ -0,0 +1,39 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +// Copyright(c) 2017-2021 Intel Corporation
> +
> +#include <linux/jiffies.h>
> +#include <linux/module.h>
> +#include <linux/pci.h>
> +
> +#include "gna_device.h"
> +#include "gna_driver.h"
> +
> +static int recovery_timeout = 60;
> +module_param(recovery_timeout, int, 0644);
> +MODULE_PARM_DESC(recovery_timeout, "Recovery timeout in seconds");

Why module parameters?!

> +struct gna_driver_private gna_drv_priv;

Global?!

> +static struct pci_driver gna_driver = {
> +       .name = GNA_DV_NAME,
> +       .probe = gna_probe,
> +};
> +
> +static int __init gna_drv_init(void)
> +{
> +       gna_drv_priv.recovery_timeout_jiffies = msecs_to_jiffies(recovery_timeout * 1000);
> +
> +       return pci_register_driver(&gna_driver);
> +}
> +
> +static void __exit gna_drv_exit(void)
> +{
> +       pci_unregister_driver(&gna_driver);
> +}
> +
> +module_init(gna_drv_init);
> +module_exit(gna_drv_exit);

What is this entire module for?!

Really you should not split this like above. This belongs to the PCI
glue driver.


> +MODULE_AUTHOR("Intel Corporation");
> +MODULE_DESCRIPTION("Intel(R) Gaussian & Neural Accelerator (Intel(R) GNA) Driver");
> +MODULE_LICENSE("GPL");
> diff --git a/drivers/misc/intel/gna/gna_driver.h b/drivers/misc/intel/gna/gna_driver.h
> new file mode 100644
> index 000000000000..ed507ea10866
> --- /dev/null
> +++ b/drivers/misc/intel/gna/gna_driver.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +/* Copyright(c) 2017-2021 Intel Corporation */
> +
> +#ifndef __GNA_DRIVER_H__
> +#define __GNA_DRIVER_H__
> +
> +#define GNA_DV_NAME    "intel_gna"
> +
> +struct gna_driver_private {
> +       int recovery_timeout_jiffies;
> +};
> +
> +extern struct gna_driver_private gna_drv_priv;
> +
> +#endif /* __GNA_DRIVER_H__ */
> diff --git a/include/uapi/misc/intel/gna.h b/include/uapi/misc/intel/gna.h
> new file mode 100644
> index 000000000000..a7e435b74a0a
> --- /dev/null
> +++ b/include/uapi/misc/intel/gna.h
> @@ -0,0 +1,155 @@
> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note */
> +/* Copyright(c) 2017-2021 Intel Corporation */
> +
> +#ifndef _UAPI_GNA_H_
> +#define _UAPI_GNA_H_
> +
> +#if defined(__cplusplus)
> +extern "C" {
> +#endif

> +#include <linux/types.h>
> +#include <linux/ioctl.h>
> +#include <linux/const.h>

Ordered?

> +#ifndef __user
> +#define __user
> +#endif

What for?

> +/* Operation modes */
> +#define GNA_MODE_GMM   0
> +#define GNA_MODE_XNN   1
> +
> +#define GNA_PARAM_DEVICE_ID            1
> +#define GNA_PARAM_RECOVERY_TIMEOUT     2
> +#define GNA_PARAM_DEVICE_TYPE          3
> +#define GNA_PARAM_INPUT_BUFFER_S       4
> +
> +#define GNA_STS_SCORE_COMPLETED                _BITUL(0)
> +#define GNA_STS_STATISTICS_VALID       _BITUL(3)
> +#define GNA_STS_PCI_MMU_ERR            _BITUL(4)
> +#define GNA_STS_PCI_DMA_ERR            _BITUL(5)
> +#define GNA_STS_PCI_UNEXCOMPL_ERR      _BITUL(6)
> +#define GNA_STS_VA_OOR                 _BITUL(7)
> +#define GNA_STS_PARAM_OOR              _BITUL(8)
> +#define GNA_STS_SATURATE               _BITUL(17)
> +
> +#define GNA_ERROR      (GNA_STS_PCI_DMA_ERR            | \

Better to start value on the new line.

> +                       GNA_STS_PCI_MMU_ERR             | \
> +                       GNA_STS_PCI_UNEXCOMPL_ERR       | \
> +                       GNA_STS_PARAM_OOR               | \
> +                       GNA_STS_VA_OOR)
> +
> +#define GNA_DEV_TYPE_0_9       0x09
> +#define GNA_DEV_TYPE_1_0       0x10
> +#define GNA_DEV_TYPE_2_0       0x20
> +
> +/*
> + * Structure describes part of memory to be overwritten before starting GNA
> + */
> +struct gna_memory_patch {
> +       /* offset from targeted memory */
> +       __u64 offset;
> +
> +       __u64 size;
> +       __u64 value;
> +};
> +
> +struct gna_buffer {
> +       __u64 memory_id;
> +
> +       __u64 offset;
> +       __u64 size;
> +
> +       __u64 patch_count;
> +       __u64 patches_ptr;
> +};
> +
> +/*
> + * Driver performance timestamps in nanoseconds.
> + * Values regard system boot time, but do not count during suspend.
> + */
> +struct gna_drv_perf {
> +       __u64 pre_processing;   /* driver starts pre-processing */
> +       __u64 processing;       /* hw starts processing */
> +       __u64 hw_completed;     /* hw finishes processing */
> +       __u64 completion;       /* driver finishes post-processing */
> +};
> +
> +struct gna_hw_perf {
> +       __u64 total;
> +       __u64 stall;
> +};
> +
> +struct gna_compute_cfg {
> +       __u32 layer_base;
> +       __u32 layer_count;
> +
> +       /* List of GNA memory buffers */
> +       __u64 buffers_ptr;
> +       __u64 buffer_count;
> +
> +       __u8 active_list_on;
> +       __u8 gna_mode;
> +       __u8 hw_perf_encoding;
> +       __u8 pad[5];
> +};
> +
> +union gna_parameter {
> +       struct {
> +               __u64 id;
> +       } in;
> +
> +       struct {
> +               __u64 value;
> +       } out;
> +};
> +
> +union gna_memory_map {
> +       struct {
> +               __u64 address;
> +               __u32 size;
> +               __u32 pad;
> +       } in;
> +
> +       struct {
> +               __u64 memory_id;
> +       } out;
> +};
> +
> +union gna_compute {
> +       struct {
> +               struct gna_compute_cfg config;
> +       } in;
> +
> +       struct {
> +               __u64 request_id;
> +       } out;
> +};
> +
> +union gna_wait {
> +       struct {
> +               __u64 request_id;
> +               __u32 timeout;
> +               __u32 pad;
> +       } in;
> +
> +       struct {
> +               __u32 hw_status;
> +               __u32 pad;
> +               struct gna_drv_perf drv_perf;
> +               struct gna_hw_perf hw_perf;
> +       } out;
> +};

For all unions:
How do you know which branch is used (out, in)? What field and where
in the ABI points to that?

> +#define GNA_GET_PARAMETER      _IOWR('C', 0x01, union gna_parameter)
> +#define GNA_MAP_MEMORY         _IOWR('C', 0x02, union gna_memory_map)
> +#define GNA_UNMAP_MEMORY       _IOWR('C', 0x03, __u64)
> +#define GNA_COMPUTE            _IOWR('C', 0x04, union gna_compute)
> +#define GNA_WAIT               _IOWR('C', 0x05, union gna_wait)
> +
> +#if defined(__cplusplus)
> +}
> +#endif
> +
> +#endif /* _UAPI_GNA_H_ */
> --
> 2.28.0
>


-- 
With Best Regards,
Andy Shevchenko