Hi Sinan,
On 01/29/2016 11:35 PM, Sinan Kaya wrote:
> In situations where the userspace driver is stopped abnormally and the
> VFIO platform device is released, the assigned HW device currently is
> left running. As a consequence the HW device might continue issuing IRQs
> and performing DMA accesses.
>
> This patch is implementing a reset driver for HIDMA platform driver.
> This gets called by the VFIO platform reset interface.
>
> Signed-off-by: Sinan Kaya <okaya@xxxxxxxxxxxxxx>
> ---
> drivers/vfio/platform/reset/Kconfig | 9 ++
> drivers/vfio/platform/reset/Makefile | 2 +
> .../vfio/platform/reset/vfio_platform_qcomhidma.c | 99 ++++++++++++++++++++++
> 3 files changed, 110 insertions(+)
> create mode 100644 drivers/vfio/platform/reset/vfio_platform_qcomhidma.c
>
> diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig
> index 70cccc5..d02b3b5 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_QCOMHIDMA_RESET
> + tristate "VFIO support for Qualcomm Technologies HIDMA reset"
> + depends on VFIO_PLATFORM
> + help
> + Enables the VFIO platform driver to handle reset for Qualcomm Technologies
> + HIDMA Channel.
> +
> + 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..ec7748a 100644
> --- a/drivers/vfio/platform/reset/Makefile
> +++ b/drivers/vfio/platform/reset/Makefile
> @@ -1,7 +1,9 @@
> vfio-platform-calxedaxgmac-y := vfio_platform_calxedaxgmac.o
> vfio-platform-amdxgbe-y := vfio_platform_amdxgbe.o
> +vfio-platform-qcomhidma-y := vfio_platform_qcomhidma.o
>
> ccflags-y += -Idrivers/vfio/platform
>
> obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC_RESET) += vfio-platform-calxedaxgmac.o
> +obj-$(CONFIG_VFIO_PLATFORM_QCOMHIDMA_RESET) += vfio-platform-qcomhidma.o
> obj-$(CONFIG_VFIO_PLATFORM_AMDXGBE_RESET) += vfio-platform-amdxgbe.o
> diff --git a/drivers/vfio/platform/reset/vfio_platform_qcomhidma.c b/drivers/vfio/platform/reset/vfio_platform_qcomhidma.c
> new file mode 100644
> index 0000000..4e7a59c
> --- /dev/null
> +++ b/drivers/vfio/platform/reset/vfio_platform_qcomhidma.c
> @@ -0,0 +1,99 @@
> +/*
> + * Qualcomm Technologies HIDMA VFIO Reset Driver
> + *
> + * Copyright (c) 2016, The Linux Foundation. All rights reserved.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only 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.
> + */
> +
> +#include <linux/module.h>
> +#include <linux/kernel.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/device.h>
> +#include <linux/iopoll.h>
> +
> +#include "vfio_platform_private.h"
> +
> +#define TRCA_CTRLSTS_OFFSET 0x000
> +#define EVCA_CTRLSTS_OFFSET 0x000
> +
> +#define CH_CONTROL_MASK GENMASK(7, 0)
> +#define CH_STATE_MASK GENMASK(7, 0)
> +#define CH_STATE_BIT_POS 0x8
> +
> +#define HIDMA_CH_STATE(val) \
> + ((val >> CH_STATE_BIT_POS) & CH_STATE_MASK)
> +
> +#define EVCA_IRQ_EN_OFFSET 0x110
> +
> +#define CH_RESET 9
> +#define CH_DISABLED 0
> +
> +int vfio_platform_qcomhidma_reset(struct vfio_platform_device *vdev)
> +{
> + struct vfio_platform_region trreg;
> + struct vfio_platform_region evreg;
> + u32 val;
> + int ret;
> +
> + if (vdev->num_regions != 2)
> + return -ENODEV;
> +
> + trreg = vdev->regions[0];
> + if (!trreg.ioaddr) {
> + trreg.ioaddr =
> + ioremap_nocache(trreg.addr, trreg.size);
this is going to leak. See "vfio: platform: reset: calxedaxgmac: fix
ioaddr leak".
> + if (!trreg.ioaddr)
> + return -ENOMEM;
> + }
> +
> + evreg = vdev->regions[1];
> + if (!evreg.ioaddr) {
> + evreg.ioaddr =
> + ioremap_nocache(evreg.addr, evreg.size);
same here
> + if (!evreg.ioaddr)
> + return -ENOMEM;
> + }
> +
I understood the device is a kind of SR-IOV platform device. When the VF
gets reset are there any interactions with the management driver? Is it
handled by HW?
Best Regards
Eric
> + /* disable IRQ */
> + writel(0, evreg.ioaddr + EVCA_IRQ_EN_OFFSET);
> +
> + /* reset both transfer and event channels */
> + val = readl(trreg.ioaddr + TRCA_CTRLSTS_OFFSET);
> + val &= ~(CH_CONTROL_MASK << 16);
> + val |= CH_RESET << 16;
> + writel(val, trreg.ioaddr + TRCA_CTRLSTS_OFFSET);
> +
> + ret = readl_poll_timeout(trreg.ioaddr + TRCA_CTRLSTS_OFFSET, val,
> + HIDMA_CH_STATE(val) == CH_DISABLED, 1000,
> + 10000);
> + if (ret)
> + return ret;
> +
> + val = readl(evreg.ioaddr + EVCA_CTRLSTS_OFFSET);
> + val &= ~(CH_CONTROL_MASK << 16);
> + val |= CH_RESET << 16;
> + writel(val, evreg.ioaddr + EVCA_CTRLSTS_OFFSET);
> +
> + ret = readl_poll_timeout(evreg.ioaddr + EVCA_CTRLSTS_OFFSET, val,
> + HIDMA_CH_STATE(val) == CH_DISABLED, 1000,
> + 10000);
> + if (ret)
> + return ret;
> +
> + pr_info("HIDMA channel reset\n");
> + return 0;
> +}
> +module_vfio_reset_handler("qcom,hidma", NULL,
> + vfio_platform_qcomhidma_reset);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("Reset support for Qualcomm Technologies HIDMA device");
>
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