vfio: platform: reset: add support for XHCI reset hook
diff mbox series

Message ID 20190711143159.21961-1-gregory.clement@bootlin.com
State New
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  • vfio: platform: reset: add support for XHCI reset hook
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Commit Message

Gregory CLEMENT July 11, 2019, 2:31 p.m. UTC
The VFIO reset hook is called every time a platform device is passed
to a guest or removed from a guest.

When the XHCI device is unbound from the host, the host driver
disables the XHCI clocks/phys/regulators so when the device is passed
to the guest it becomes dis-functional.

This initial implementation uses the VFIO reset hook to enable the
XHCI clocks/phys on behalf of the guest.

Ported from Marvell LSP code originally written by Yehuda Yitschak

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
 drivers/vfio/platform/reset/Kconfig           |  8 +++
 drivers/vfio/platform/reset/Makefile          |  2 +
 .../vfio/platform/reset/vfio_platform_xhci.c  | 60 +++++++++++++++++++
 3 files changed, 70 insertions(+)
 create mode 100644 drivers/vfio/platform/reset/vfio_platform_xhci.c

Comments

Auger Eric July 12, 2019, 7:03 a.m. UTC | #1
Hi Gregory,

On 7/11/19 4:31 PM, Gregory CLEMENT wrote:
> The VFIO reset hook is called every time a platform device is passed
> to a guest or removed from a guest.
> 
> When the XHCI device is unbound from the host, the host driver
> disables the XHCI clocks/phys/regulators so when the device is passed
> to the guest it becomes dis-functional.
> 
> This initial implementation uses the VFIO reset hook to enable the
> XHCI clocks/phys on behalf of the guest.

the platform reset module must also make sure there are no more DMA
requests and interrupts that can be sent by the device anymore.
> 
> Ported from Marvell LSP code originally written by Yehuda Yitschak
> 
> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> ---
>  drivers/vfio/platform/reset/Kconfig           |  8 +++
>  drivers/vfio/platform/reset/Makefile          |  2 +
>  .../vfio/platform/reset/vfio_platform_xhci.c  | 60 +++++++++++++++++++
>  3 files changed, 70 insertions(+)
>  create mode 100644 drivers/vfio/platform/reset/vfio_platform_xhci.c
> 
> diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig
> index 392e3c09def0..14f620fd250d 100644
> --- a/drivers/vfio/platform/reset/Kconfig
> +++ b/drivers/vfio/platform/reset/Kconfig
> @@ -22,3 +22,11 @@ config VFIO_PLATFORM_BCMFLEXRM_RESET
>  	  Enables the VFIO platform driver to handle reset for Broadcom FlexRM
>  
>  	  If you don't know what to do here, say N.
> +
> +config VFIO_PLATFORM_XHCI_RESET
> +	tristate "VFIO support for USB XHCI reset"
> +	depends on VFIO_PLATFORM
> +	help
> +	  Enables the VFIO platform driver to handle reset for USB XHCI
> +
> +	  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 7294c5ea122e..d84c4d3dc041 100644
> --- a/drivers/vfio/platform/reset/Makefile
> +++ b/drivers/vfio/platform/reset/Makefile
> @@ -1,7 +1,9 @@
>  # SPDX-License-Identifier: GPL-2.0
>  vfio-platform-calxedaxgmac-y := vfio_platform_calxedaxgmac.o
>  vfio-platform-amdxgbe-y := vfio_platform_amdxgbe.o
> +vfio-platform-xhci-y := vfio_platform_xhci.o
>  
>  obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC_RESET) += vfio-platform-calxedaxgmac.o
>  obj-$(CONFIG_VFIO_PLATFORM_AMDXGBE_RESET) += vfio-platform-amdxgbe.o
>  obj-$(CONFIG_VFIO_PLATFORM_BCMFLEXRM_RESET) += vfio_platform_bcmflexrm.o
> +obj-$(CONFIG_VFIO_PLATFORM_XHCI_RESET) += vfio-platform-xhci.o
> diff --git a/drivers/vfio/platform/reset/vfio_platform_xhci.c b/drivers/vfio/platform/reset/vfio_platform_xhci.c
> new file mode 100644
> index 000000000000..7b75a04402ee
> --- /dev/null
> +++ b/drivers/vfio/platform/reset/vfio_platform_xhci.c
> @@ -0,0 +1,60 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * VFIO platform driver specialized for XHCI reset
> + *
> + * Copyright 2016 Marvell Semiconductors, Inc.
> + *
> + */
> +
> +#include <linux/clk.h>
> +#include <linux/device.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
io, init, kernel should be removable (noticed init and kernel.h also are
in other reset modules though)
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/phy/phy.h>
> +#include <linux/usb/phy.h>
> +
> +#include "../vfio_platform_private.h"
> +
> +#define MAX_XHCI_CLOCKS		4
Where does this number come from?

From Documentation/devicetree/bindings/usb/usb-xhci.txt I understand
there are max 2 clocks, "core" and "reg" (I don't have any specific
knowledge on the device though).

> +#define MAX_XHCI_PHYS		2
not used
> +
> +int vfio_platform_xhci_reset(struct vfio_platform_device *vdev)
> +{
> +	struct device *dev = vdev->device;
> +	struct device_node *np = dev->of_node;
> +	struct usb_phy *usb_phy;
> +	struct clk *clk;
> +	int ret, i;
> +
> +	/*
> +	 * Compared to the native driver, no need to handle the
> +	 * deferred case, because the resources are already
> +	 * there
> +	 */
> +	for (i = 0; i < MAX_XHCI_CLOCKS; i++) {
> +		clk = of_clk_get(np, i);
> +		if (!IS_ERR(clk)) {
> +			ret = clk_prepare_enable(clk);
> +			if (ret)
> +				return -ENODEV;
return ret?
> +		}
> +	}
> +
> +	usb_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 0);
> +	if (!IS_ERR(usb_phy)) {
> +		ret = usb_phy_init(usb_phy);
> +		if (ret)
> +			return -ENODEV;
return ret?
> +	}

> +
> +	return 0;
> +}
> +
> +module_vfio_reset_handler("generic-xhci", vfio_platform_xhci_reset);
> +
> +MODULE_AUTHOR("Yehuda Yitschak");
> +MODULE_DESCRIPTION("Reset support for XHCI vfio platform device");
> +MODULE_LICENSE("GPL");
> 
Thanks

Eric
Gregory CLEMENT July 15, 2019, 3:03 p.m. UTC | #2
Hi Eric,

> Hi Gregory,
>
> On 7/11/19 4:31 PM, Gregory CLEMENT wrote:
>> The VFIO reset hook is called every time a platform device is passed
>> to a guest or removed from a guest.
>> 
>> When the XHCI device is unbound from the host, the host driver
>> disables the XHCI clocks/phys/regulators so when the device is passed
>> to the guest it becomes dis-functional.
>> 
>> This initial implementation uses the VFIO reset hook to enable the
>> XHCI clocks/phys on behalf of the guest.
>
> the platform reset module must also make sure there are no more DMA
> requests and interrupts that can be sent by the device anymore.

OK I will take care of it too.


>> 
>> Ported from Marvell LSP code originally written by Yehuda Yitschak
>> 
>> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
>> ---
>>  drivers/vfio/platform/reset/Kconfig           |  8 +++
>>  drivers/vfio/platform/reset/Makefile          |  2 +
>>  .../vfio/platform/reset/vfio_platform_xhci.c  | 60 +++++++++++++++++++
>>  3 files changed, 70 insertions(+)
>>  create mode 100644 drivers/vfio/platform/reset/vfio_platform_xhci.c
>> 
>> diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig
>> index 392e3c09def0..14f620fd250d 100644
>> --- a/drivers/vfio/platform/reset/Kconfig
>> +++ b/drivers/vfio/platform/reset/Kconfig
>> @@ -22,3 +22,11 @@ config VFIO_PLATFORM_BCMFLEXRM_RESET
>>  	  Enables the VFIO platform driver to handle reset for Broadcom FlexRM
>>  
>>  	  If you don't know what to do here, say N.
>> +
>> +config VFIO_PLATFORM_XHCI_RESET
>> +	tristate "VFIO support for USB XHCI reset"
>> +	depends on VFIO_PLATFORM
>> +	help
>> +	  Enables the VFIO platform driver to handle reset for USB XHCI
>> +
>> +	  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 7294c5ea122e..d84c4d3dc041 100644
>> --- a/drivers/vfio/platform/reset/Makefile
>> +++ b/drivers/vfio/platform/reset/Makefile
>> @@ -1,7 +1,9 @@
>>  # SPDX-License-Identifier: GPL-2.0
>>  vfio-platform-calxedaxgmac-y := vfio_platform_calxedaxgmac.o
>>  vfio-platform-amdxgbe-y := vfio_platform_amdxgbe.o
>> +vfio-platform-xhci-y := vfio_platform_xhci.o
>>  
>>  obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC_RESET) += vfio-platform-calxedaxgmac.o
>>  obj-$(CONFIG_VFIO_PLATFORM_AMDXGBE_RESET) += vfio-platform-amdxgbe.o
>>  obj-$(CONFIG_VFIO_PLATFORM_BCMFLEXRM_RESET) += vfio_platform_bcmflexrm.o
>> +obj-$(CONFIG_VFIO_PLATFORM_XHCI_RESET) += vfio-platform-xhci.o
>> diff --git a/drivers/vfio/platform/reset/vfio_platform_xhci.c b/drivers/vfio/platform/reset/vfio_platform_xhci.c
>> new file mode 100644
>> index 000000000000..7b75a04402ee
>> --- /dev/null
>> +++ b/drivers/vfio/platform/reset/vfio_platform_xhci.c
>> @@ -0,0 +1,60 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * VFIO platform driver specialized for XHCI reset
>> + *
>> + * Copyright 2016 Marvell Semiconductors, Inc.
>> + *
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/device.h>
>> +#include <linux/init.h>
>> +#include <linux/io.h>
>> +#include <linux/kernel.h>
> io, init, kernel should be removable (noticed init and kernel.h also are
> in other reset modules though)

OK

>> +#include <linux/module.h>
>> +#include <linux/of.h>
>> +#include <linux/phy/phy.h>
>> +#include <linux/usb/phy.h>
>> +
>> +#include "../vfio_platform_private.h"
>> +
>> +#define MAX_XHCI_CLOCKS		4
> Where does this number come from?
>
> From Documentation/devicetree/bindings/usb/usb-xhci.txt I understand
> there are max 2 clocks, "core" and "reg" (I don't have any specific
> knowledge on the device though).

Right, I guess the intent was to be future proof if there is more clocks
needed, but as we don't know, it's better to use the number of clokck we
know.

>
>> +#define MAX_XHCI_PHYS		2
> not used

Right!

>> +
>> +int vfio_platform_xhci_reset(struct vfio_platform_device *vdev)
>> +{
>> +	struct device *dev = vdev->device;
>> +	struct device_node *np = dev->of_node;
>> +	struct usb_phy *usb_phy;
>> +	struct clk *clk;
>> +	int ret, i;
>> +
>> +	/*
>> +	 * Compared to the native driver, no need to handle the
>> +	 * deferred case, because the resources are already
>> +	 * there
>> +	 */
>> +	for (i = 0; i < MAX_XHCI_CLOCKS; i++) {
>> +		clk = of_clk_get(np, i);
>> +		if (!IS_ERR(clk)) {
>> +			ret = clk_prepare_enable(clk);
>> +			if (ret)
>> +				return -ENODEV;
> return ret?

OK

>> +		}
>> +	}
>> +
>> +	usb_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 0);
>> +	if (!IS_ERR(usb_phy)) {
>> +		ret = usb_phy_init(usb_phy);
>> +		if (ret)
>> +			return -ENODEV;
> return ret?

OK

Thanks,

Gregory

>> +	}
>
>> +
>> +	return 0;
>> +}
>> +
>> +module_vfio_reset_handler("generic-xhci", vfio_platform_xhci_reset);
>> +
>> +MODULE_AUTHOR("Yehuda Yitschak");
>> +MODULE_DESCRIPTION("Reset support for XHCI vfio platform device");
>> +MODULE_LICENSE("GPL");
>> 
> Thanks
>
> Eric

Patch
diff mbox series

diff --git a/drivers/vfio/platform/reset/Kconfig b/drivers/vfio/platform/reset/Kconfig
index 392e3c09def0..14f620fd250d 100644
--- a/drivers/vfio/platform/reset/Kconfig
+++ b/drivers/vfio/platform/reset/Kconfig
@@ -22,3 +22,11 @@  config VFIO_PLATFORM_BCMFLEXRM_RESET
 	  Enables the VFIO platform driver to handle reset for Broadcom FlexRM
 
 	  If you don't know what to do here, say N.
+
+config VFIO_PLATFORM_XHCI_RESET
+	tristate "VFIO support for USB XHCI reset"
+	depends on VFIO_PLATFORM
+	help
+	  Enables the VFIO platform driver to handle reset for USB XHCI
+
+	  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 7294c5ea122e..d84c4d3dc041 100644
--- a/drivers/vfio/platform/reset/Makefile
+++ b/drivers/vfio/platform/reset/Makefile
@@ -1,7 +1,9 @@ 
 # SPDX-License-Identifier: GPL-2.0
 vfio-platform-calxedaxgmac-y := vfio_platform_calxedaxgmac.o
 vfio-platform-amdxgbe-y := vfio_platform_amdxgbe.o
+vfio-platform-xhci-y := vfio_platform_xhci.o
 
 obj-$(CONFIG_VFIO_PLATFORM_CALXEDAXGMAC_RESET) += vfio-platform-calxedaxgmac.o
 obj-$(CONFIG_VFIO_PLATFORM_AMDXGBE_RESET) += vfio-platform-amdxgbe.o
 obj-$(CONFIG_VFIO_PLATFORM_BCMFLEXRM_RESET) += vfio_platform_bcmflexrm.o
+obj-$(CONFIG_VFIO_PLATFORM_XHCI_RESET) += vfio-platform-xhci.o
diff --git a/drivers/vfio/platform/reset/vfio_platform_xhci.c b/drivers/vfio/platform/reset/vfio_platform_xhci.c
new file mode 100644
index 000000000000..7b75a04402ee
--- /dev/null
+++ b/drivers/vfio/platform/reset/vfio_platform_xhci.c
@@ -0,0 +1,60 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * VFIO platform driver specialized for XHCI reset
+ *
+ * Copyright 2016 Marvell Semiconductors, Inc.
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy/phy.h>
+#include <linux/usb/phy.h>
+
+#include "../vfio_platform_private.h"
+
+#define MAX_XHCI_CLOCKS		4
+#define MAX_XHCI_PHYS		2
+
+int vfio_platform_xhci_reset(struct vfio_platform_device *vdev)
+{
+	struct device *dev = vdev->device;
+	struct device_node *np = dev->of_node;
+	struct usb_phy *usb_phy;
+	struct clk *clk;
+	int ret, i;
+
+	/*
+	 * Compared to the native driver, no need to handle the
+	 * deferred case, because the resources are already
+	 * there
+	 */
+	for (i = 0; i < MAX_XHCI_CLOCKS; i++) {
+		clk = of_clk_get(np, i);
+		if (!IS_ERR(clk)) {
+			ret = clk_prepare_enable(clk);
+			if (ret)
+				return -ENODEV;
+		}
+	}
+
+	usb_phy = devm_usb_get_phy_by_phandle(dev, "usb-phy", 0);
+	if (!IS_ERR(usb_phy)) {
+		ret = usb_phy_init(usb_phy);
+		if (ret)
+			return -ENODEV;
+	}
+
+	return 0;
+}
+
+module_vfio_reset_handler("generic-xhci", vfio_platform_xhci_reset);
+
+MODULE_AUTHOR("Yehuda Yitschak");
+MODULE_DESCRIPTION("Reset support for XHCI vfio platform device");
+MODULE_LICENSE("GPL");