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

Anup Patel
2017-08-17T03:45:46Z

On Fri, Aug 11, 2017 at 12:53 AM, Alex Williamson
<alex.williamson@redhat.com> wrote:
> 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.

Sure, I will use "--timeout" instead of "timeout--" which will
fix the issue.

Thanks for pointing.

Regards,
Anup