[PATCH v4] vfio: platform: reset: Add Broadcom FlexRM reset module

Alex Williamson
2017-08-10T19:23:38Z

On Wed, 2 Aug 2017 11:08:30 +0530
Anup Patel <anup.patel@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@broadcom.com>
> Reviewed-by: Oza Oza <oza.oza@broadcom.com>
> Reviewed-by: Scott Branden <scott.branden@broadcom.com>
> Reviewed-by: Eric Auger <eric.auger@redhat.com>
> ---
> drivers/vfio/platform/reset/Kconfig | 8 ++
> drivers/vfio/platform/reset/Makefile | 1 +
> .../vfio/platform/reset/vfio_platform_bcmflexrm.c | 100 +++++++++++++++++++++
> 3 files changed, 109 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..8833805 100644
> --- a/drivers/vfio/platform/reset/Kconfig
> +++ b/drivers/vfio/platform/reset/Kconfig
> @@ -13,3 +13,11 @@ 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)
> + 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..104c3c1
> --- /dev/null
> +++ b/drivers/vfio/platform/reset/vfio_platform_bcmflexrm.c
> @@ -0,0 +1,100 @@
> +/*
> + * 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 version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program. If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +/*
> + * This driver provides reset support for Broadcom FlexRM ring manager
> + * to VFIO platform.
> + */
> +
> +#include <linux/delay.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);
> +
> + /* Flush ring with timeout of 1s */
> + timeout = 1000;
> + 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) {
> + pr_warn("VFIO FlexRM shutdown timeout\n");
> + return -ETIMEDOUT;
> + }

This doesn't work, timeout is ~0 here.

> +
> + return 0;
> +}
> +
> +static int vfio_platform_bcmflexrm_reset(struct vfio_platform_device *vdev)
> +{
> + int rc = 0;
> + void __iomem *ring;
> + 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)
> + break;
> + }
> + }
> +
> + return rc;
> +}
> +
> +module_vfio_reset_handler("brcm,iproc-flexrm-mbox",
> + vfio_platform_bcmflexrm_reset);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_AUTHOR("Anup Patel <anup.patel@broadcom.com>");
> +MODULE_DESCRIPTION("Reset support for Broadcom FlexRM VFIO platform device");