On Fri, 2015-04-17 at 15:37 +0200, Eric Auger wrote: > This patch introduces a specialized vfio platform driver for the > calxeda xgmac. On top of the generic vfio platform driver functionalities, > it implements the reset modality. This latter basically disables interrupts > and stops DMA transfers. > > Code is inherited from calxeda xgmac native driver > > Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx> > --- > drivers/vfio/platform/Kconfig | 2 + > drivers/vfio/platform/Makefile | 2 + > drivers/vfio/platform/reset/Kconfig | 7 ++ > drivers/vfio/platform/reset/Makefile | 5 + > .../platform/reset/vfio_platform_calxedaxgmac.c | 109 +++++++++++++++++++++ > 5 files changed, 125 insertions(+) > create mode 100644 drivers/vfio/platform/reset/Kconfig > create mode 100644 drivers/vfio/platform/reset/Makefile > create mode 100644 drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c > > diff --git a/drivers/vfio/platform/Kconfig b/drivers/vfio/platform/Kconfig > index 9a4403e..1df7477 100644 > --- a/drivers/vfio/platform/Kconfig > +++ b/drivers/vfio/platform/Kconfig > @@ -18,3 +18,5 @@ config VFIO_AMBA > framework. > > If you don't know what to do here, say N. > + > +source "drivers/vfio/platform/reset/Kconfig" > diff --git a/drivers/vfio/platform/Makefile b/drivers/vfio/platform/Makefile > index 81de144..9ce8afe 100644 > --- a/drivers/vfio/platform/Makefile > +++ b/drivers/vfio/platform/Makefile > @@ -2,7 +2,9 @@ > vfio-platform-y := vfio_platform.o vfio_platform_common.o vfio_platform_irq.o > > obj-$(CONFIG_VFIO_PLATFORM) += vfio-platform.o > +obj-$(CONFIG_VFIO_PLATFORM) += reset/ > > vfio-amba-y := vfio_amba.o > > obj-$(CONFIG_VFIO_AMBA) += vfio-amba.o > +obj-$(CONFIG_VFIO_AMBA) += reset/ > diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig > new file mode 100644 > index 0000000..2c09cea > --- /dev/null > +++ b/drivers/vfio/platform/reset/Kconfig > @@ -0,0 +1,7 @@ > +config VFIO_PLATFORM_CALXEDAXGMAC > + tristate "VFIO support for calxeda xgmac" > + depends on VFIO_PLATFORM > + help > + Support for VFIO platform driver specialized for Calxeda xgmac reset. > + > + 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 > new file mode 100644 > index 0000000..8977721 > --- /dev/null > +++ b/drivers/vfio/platform/reset/Makefile > @@ -0,0 +1,5 @@ > +vfio-platform-calxedaxgmac-y := vfio_platform_calxedaxgmac.o > + > +ccflags-y += -Idrivers/vfio/platform > + > +obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC) += vfio-platform-calxedaxgmac.o > diff --git a/drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c b/drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c > new file mode 100644 > index 0000000..729d0cd > --- /dev/null > +++ b/drivers/vfio/platform/reset/vfio_platform_calxedaxgmac.c > @@ -0,0 +1,109 @@ > +/* > + * VFIO platform driver specialized for Calxeda xgmac reset > + * reset code is inherited from calxeda xgmac native driver > + * > + * Copyright 2010-2011 Calxeda, Inc. > + * Copyright (c) 2015 Linaro Ltd. > + * www.linaro.org > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope 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/>. > + */ > + > +#include <linux/module.h> > +#include <linux/kernel.h> > +#include <linux/init.h> > +#include <linux/platform_device.h> > +#include <linux/slab.h> > +#include <linux/vfio.h> > +#include "vfio_platform_private.h" > +#include <linux/io.h> > + > +#define DRIVER_VERSION "0.1" > +#define DRIVER_AUTHOR "Eric Auger <eric.auger@xxxxxxxxxx>" > +#define DRIVER_DESC "VFIO - Calxeda xgmac vfio platform driver" > + > +/* XGMAC Register definitions */ > +#define XGMAC_CONTROL 0x00000000 /* MAC Configuration */ > + > +/* DMA Control and Status Registers */ > +#define XGMAC_DMA_CONTROL 0x00000f18 /* Ctrl (Operational Mode) */ > +#define XGMAC_DMA_INTR_ENA 0x00000f1c /* Interrupt Enable */ > + > +/* DMA Control registe defines */ > +#define DMA_CONTROL_ST 0x00002000 /* Start/Stop Transmission */ > +#define DMA_CONTROL_SR 0x00000002 /* Start/Stop Receive */ > + > +/* Common MAC defines */ > +#define MAC_ENABLE_TX 0x00000008 /* Transmitter Enable */ > +#define MAC_ENABLE_RX 0x00000004 /* Receiver Enable */ > + > +static inline void xgmac_mac_disable(void __iomem *ioaddr) > +{ > + u32 value = readl(ioaddr + XGMAC_DMA_CONTROL); > + > + value &= ~(DMA_CONTROL_ST | DMA_CONTROL_SR); > + writel(value, ioaddr + XGMAC_DMA_CONTROL); > + > + value = readl(ioaddr + XGMAC_CONTROL); > + value &= ~(MAC_ENABLE_TX | MAC_ENABLE_RX); > + writel(value, ioaddr + XGMAC_CONTROL); > +} > + > +static int vfio_platform_calxedaxgmac_reset(struct vfio_platform_device *vdev) > +{ > + struct resource *res = get_platform_resource(vdev, 0); > + void __iomem *base = phys_to_virt(res->start); > + > + if (!base) > + return -ENOMEM; > + > + /* disable IRQ */ > + writel(0, base + XGMAC_DMA_INTR_ENA); > + > + /* Disable the MAC core */ > + xgmac_mac_disable(base); > + > + return 0; > +} > + > +static int vfio_platform_calxedaxgmac_probe(struct platform_device *pdev) > +{ > + int ret; > + struct vfio_device *vfio_dev; > + struct vfio_platform_device *vpdev; > + > + ret = vfio_platform_probe(pdev); > + if (ret) > + return ret; > + > + vfio_dev = vfio_device_get_from_dev(&pdev->dev), > + vpdev = (struct vfio_platform_device *) vfio_device_data(vfio_dev); > + vpdev->reset = vfio_platform_calxedaxgmac_reset; > + > + return ret; > +} > + > +static struct platform_driver vfio_platform_calxedaxgmac_driver = { > + .driver = { > + .name = "vfio-platform-calxedaxgmac", > + }, > + .probe = vfio_platform_calxedaxgmac_probe, > + .remove = vfio_platform_remove, > +}; > + > +module_platform_driver(vfio_platform_calxedaxgmac_driver); > + > +MODULE_VERSION(DRIVER_VERSION); > +MODULE_LICENSE("GPL v2"); > +MODULE_AUTHOR(DRIVER_AUTHOR); > +MODULE_DESCRIPTION(DRIVER_DESC); I don't really understand why this needs to be a new driver that wraps around the vfio platform driver rather than just an entry in a table of available device specific reset functions, setup through the normal probe path. Do we really have no clue what the device is to be able to attach a reset function to it from the base vfio platform code? This also seems like a pain for users, who now need to figure out which vfio_platform driver to bind to a given device. If the user can figure that out, why can't the kernel just pick the right reset callback for them? Thanks, Alex -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
