[PATCH v10] vfio: platform: reset: Add Broadcom FlexRM reset module

[Anup Patel]

On Tue, Oct 3, 2017 at 10:57 AM, Anup Patel <anup.patel at broadcom.com> wrote:
> This patch adds Broadcom FlexRM low-level reset for
> VFIO platform.
>
> It will do the following:
> 1. Disable/Deactivate each FlexRM ring
> 2. Flush each FlexRM ring
>
> The cleanup sequence for FlexRM rings is adapted from
> Broadcom FlexRM mailbox driver.
>
> Signed-off-by: Anup Patel <anup.patel at broadcom.com>
> Reviewed-by: Oza Oza <oza.oza at broadcom.com>
> Reviewed-by: Scott Branden <scott.branden at broadcom.com>
> Reviewed-by: Eric Auger <eric.auger at redhat.com>
> ---
>  drivers/vfio/platform/reset/Kconfig                |   9 ++
>  drivers/vfio/platform/reset/Makefile               |   1 +
>  .../vfio/platform/reset/vfio_platform_bcmflexrm.c  | 113 +++++++++++++++++++++
>  3 files changed, 123 insertions(+)
>  create mode 100644 drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
>
> diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig
> index 70cccc5..392e3c0 100644
> --- a/drivers/vfio/platform/reset/Kconfig
> +++ b/drivers/vfio/platform/reset/Kconfig
> @@ -13,3 +13,12 @@ config VFIO_PLATFORM_AMDXGBE_RESET
>           Enables the VFIO platform driver to handle reset for AMD XGBE
>
>           If you don't know what to do here, say N.
> +
> +config VFIO_PLATFORM_BCMFLEXRM_RESET
> +       tristate "VFIO support for Broadcom FlexRM reset"
> +       depends on VFIO_PLATFORM && (ARCH_BCM_IPROC || COMPILE_TEST)
> +       default ARCH_BCM_IPROC
> +       help
> +         Enables the VFIO platform driver to handle reset for Broadcom FlexRM
> +
> +         If you don't know what to do here, say N.
> diff --git a/drivers/vfio/platform/reset/Makefile b/drivers/vfio/platform/reset/Makefile
> index 93f4e23..8d9874b 100644
> --- a/drivers/vfio/platform/reset/Makefile
> +++ b/drivers/vfio/platform/reset/Makefile
> @@ -5,3 +5,4 @@ ccflags-y += -Idrivers/vfio/platform
>
>  obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC_RESET) += vfio-platform-calxedaxgmac.o
>  obj-$(CONFIG_VFIO_PLATFORM_AMDXGBE_RESET) += vfio-platform-amdxgbe.o
> +obj-$(CONFIG_VFIO_PLATFORM_BCMFLEXRM_RESET) += vfio_platform_bcmflexrm.o
> diff --git a/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
> new file mode 100644
> index 0000000..d45c3be
> --- /dev/null
> +++ b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
> @@ -0,0 +1,113 @@
> +/*
> + * Copyright (C) 2017 Broadcom
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation version 2.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +/*
> + * This driver provides reset support for Broadcom FlexRM ring manager
> + * to VFIO platform.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +
> +#include "vfio_platform_private.h"
> +
> +/* FlexRM configuration */
> +#define RING_REGS_SIZE                                 0x10000
> +#define RING_VER_MAGIC                                 0x76303031
> +
> +/* Per-Ring register offsets */
> +#define RING_VER                                       0x000
> +#define RING_CONTROL                                   0x034
> +#define RING_FLUSH_DONE                                        0x038
> +
> +/* Register RING_CONTROL fields */
> +#define CONTROL_FLUSH_SHIFT                            5
> +
> +/* Register RING_FLUSH_DONE fields */
> +#define FLUSH_DONE_MASK                                        0x1
> +
> +static int vfio_platform_bcmflexrm_shutdown(void __iomem *ring)
> +{
> +       unsigned int timeout;
> +
> +       /* Disable/inactivate ring */
> +       writel_relaxed(0x0, ring + RING_CONTROL);
> +
> +       /* Set ring flush state */
> +       timeout = 1000; /* timeout of 1s */
> +       writel_relaxed(BIT(CONTROL_FLUSH_SHIFT), ring + RING_CONTROL);
> +       do {
> +               if (readl_relaxed(ring + RING_FLUSH_DONE) &
> +                   FLUSH_DONE_MASK)
> +                       break;
> +               mdelay(1);
> +       } while (--timeout);
> +       if (!timeout)
> +               return -ETIMEDOUT;
> +
> +       /* Clear ring flush state */
> +       timeout = 1000; /* timeout of 1s */
> +       writel_relaxed(0x0, ring + RING_CONTROL);
> +       do {
> +               if (!(readl_relaxed(ring + RING_FLUSH_DONE) &
> +                     FLUSH_DONE_MASK))
> +                       break;
> +               mdelay(1);
> +       } while (--timeout);
> +       if (!timeout)
> +               return -ETIMEDOUT;
> +
> +       return 0;
> +}
> +
> +static int vfio_platform_bcmflexrm_reset(struct vfio_platform_device *vdev)
> +{
> +       void __iomem *ring;
> +       int rc = 0, ret = 0, ring_num = 0;
> +       struct vfio_platform_region *reg = &vdev->regions[0];
> +
> +       /* Map FlexRM ring registers if not mapped */
> +       if (!reg->ioaddr) {
> +               reg->ioaddr = ioremap_nocache(reg->addr, reg->size);
> +               if (!reg->ioaddr)
> +                       return -ENOMEM;
> +       }
> +
> +       /* Discover and shutdown each FlexRM ring */
> +       for (ring = reg->ioaddr;
> +            ring < (reg->ioaddr + reg->size); ring += RING_REGS_SIZE) {
> +               if (readl_relaxed(ring + RING_VER) == RING_VER_MAGIC) {
> +                       rc = vfio_platform_bcmflexrm_shutdown(ring);
> +                       if (rc) {
> +                               dev_warn(vdev->device,
> +                                        "FlexRM ring%d shutdown error %d\n",
> +                                        ring_num, rc);
> +                               ret |= rc;
> +                       }
> +                       ring_num++;
> +               }
> +       }
> +
> +       return ret;
> +}
> +
> +module_vfio_reset_handler("brcm,iproc-flexrm-mbox",
> +                         vfio_platform_bcmflexrm_reset);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Anup Patel <anup.patel at broadcom.com>");
> +MODULE_DESCRIPTION("Reset support for Broadcom FlexRM VFIO platform device");
> --
> 2.7.4
>

Hi All,

Any comments on this one ?

Regards,
Anup