[RFC,3/3] VFIO: platform: add vfio-platform-calxedaxgmac driver

Message ID 1429277833-28663-4-git-send-email-eric.auger@linaro.org
State New
Headers show

Commit Message

Auger Eric April 17, 2015, 1:37 p.m.
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@linaro.org>
---
 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

Comments

Auger Eric April 17, 2015, 3:01 p.m. | #1
Hi Alex,
On 04/17/2015 04:29 PM, Alex Williamson wrote:
> 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@linaro.org>
>> ---
>>  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@linaro.org>"
>> +#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,

Yes I can do the proposed way. I can get access to the compat string of
the device and according to that info I will choose some proper reset
function. I will respin shortly taking into account the other comments.

Thanks!

Eric
> 
> Alex
>

Patch

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@linaro.org>"
+#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);