Add an I2C bus driver for virtio para-virtualization. The controller can be emulated by the backend driver in any device model software by following the virtio protocol. This driver communicates with the backend driver through a virtio I2C message structure which includes following parts: - Header: i2c_msg addr, flags, len. - Data buffer: the pointer to the I2C msg data. - Status: the processing result from the backend. People may implement different backend drivers to emulate different controllers according to their needs. A backend example can be found in the device model of the open source project ACRN. For more information, please refer to https://projectacrn.org. The virtio device ID 34 is used for this I2C adpter since IDs before 34 have been reserved by other virtio devices. Co-developed-by: Conghui Chen <conghui.chen at intel.com> Signed-off-by: Conghui Chen <conghui.chen at intel.com> Signed-off-by: Jie Deng <jie.deng at intel.com> Reviewed-by: Shuo Liu <shuo.a.liu at intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com> --- The device ID request: https://github.com/oasis-tcs/virtio-spec/issues/85 Changes in v2: - Addressed comments received from Michael, Andy and Jason. drivers/i2c/busses/Kconfig | 11 ++ drivers/i2c/busses/Makefile | 3 + drivers/i2c/busses/i2c-virtio.c | 271 ++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/virtio_ids.h | 1 + 4 files changed, 286 insertions(+) create mode 100644 drivers/i2c/busses/i2c-virtio.c diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index 293e7a0..70c8e30 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -21,6 +21,17 @@ config I2C_ALI1535 This driver can also be built as a module. If so, the module will be called i2c-ali1535. +config I2C_VIRTIO + tristate "Virtio I2C Adapter" + depends on VIRTIO + help + If you say yes to this option, support will be included for the virtio + i2c adapter driver. The hardware can be emulated by any device model + software according to the virtio protocol. + + This driver can also be built as a module. If so, the module + will be called i2c-virtio. + config I2C_ALI1563 tristate "ALI 1563" depends on PCI diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 19aff0e..821acfa 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -6,6 +6,9 @@ # ACPI drivers obj-$(CONFIG_I2C_SCMI) += i2c-scmi.o +# VIRTIO I2C host controller driver +obj-$(CONFIG_I2C_VIRTIO) += i2c-virtio.o + # PC SMBus host controller drivers obj-$(CONFIG_I2C_ALI1535) += i2c-ali1535.o obj-$(CONFIG_I2C_ALI1563) += i2c-ali1563.o diff --git a/drivers/i2c/busses/i2c-virtio.c b/drivers/i2c/busses/i2c-virtio.c new file mode 100644 index 0000000..aff1a9a --- /dev/null +++ b/drivers/i2c/busses/i2c-virtio.c @@ -0,0 +1,271 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Virtio I2C Bus Driver + * + * Copyright (c) 2020 Intel Corporation. All rights reserved. + */ + +#include <linux/acpi.h> +#include <linux/completion.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/io.h> +#include <linux/jiffies.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/wait.h> + +#include <linux/virtio.h> +#include <linux/virtio_ids.h> +#include <linux/virtio_config.h> + +#define VIRTIO_I2C_MSG_OK 0 +#define VIRTIO_I2C_MSG_ERR 1 + +/** + * struct virtio_i2c_hdr - the virtio I2C message header structure + * @addr: i2c_msg addr, the slave address + * @flags: i2c_msg flags + * @len: i2c_msg len + */ +struct virtio_i2c_hdr { + __le16 addr; + __le16 flags; + __le16 len; +}; + +/** + * struct virtio_i2c_msg - the virtio I2C message structure + * @hdr: the virtio I2C message header + * @buf: virtio I2C message data buffer + * @status: the processing result from the backend + */ +struct virtio_i2c_msg { + struct virtio_i2c_hdr hdr; + u8 *buf; + u8 status; +}; + +/** + * struct virtio_i2c - virtio I2C data + * @vdev: virtio device for this controller + * @completion: completion of virtio I2C message + * @vmsg: the virtio I2C message for communication + * @adap: I2C adapter for this controller + * @i2c_lock: lock for virtqueue processing + * @vq: the virtio virtqueue for communication + */ +struct virtio_i2c { + struct virtio_device *vdev; + struct completion completion; + struct virtio_i2c_msg vmsg; + struct i2c_adapter adap; + struct mutex i2c_lock; + struct virtqueue *vq; +}; + +static void virtio_i2c_msg_done(struct virtqueue *vq) +{ + struct virtio_i2c *vi = vq->vdev->priv; + + complete(&vi->completion); +} + +static int virtio_i2c_add_msg(struct virtqueue *vq, + struct virtio_i2c_msg *vmsg, + struct i2c_msg *msg) +{ + struct scatterlist *sgs[3], hdr, bout, bin, status; + int outcnt = 0, incnt = 0; + + if (!msg->len) + return -EINVAL; + + vmsg->hdr.addr = cpu_to_le16(msg->addr); + vmsg->hdr.flags = cpu_to_le16(msg->flags); + vmsg->hdr.len = cpu_to_le16(msg->len); + + vmsg->buf = kzalloc(msg->len, GFP_KERNEL); + if (!vmsg->buf) + return -ENOMEM; + + sg_init_one(&hdr, &vmsg->hdr, sizeof(struct virtio_i2c_hdr)); + sgs[outcnt++] = &hdr; + if (msg->flags & I2C_M_RD) { + sg_init_one(&bin, vmsg->buf, msg->len); + sgs[outcnt + incnt++] = &bin; + } else { + memcpy(vmsg->buf, msg->buf, msg->len); + sg_init_one(&bout, vmsg->buf, msg->len); + sgs[outcnt++] = &bout; + } + sg_init_one(&status, &vmsg->status, sizeof(vmsg->status)); + sgs[outcnt + incnt++] = &status; + + return virtqueue_add_sgs(vq, sgs, outcnt, incnt, vmsg, GFP_KERNEL); +} + +static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) +{ + struct virtio_i2c *vi = i2c_get_adapdata(adap); + struct virtqueue *vq = vi->vq; + struct virtio_i2c_msg *vmsg; + unsigned long time_left; + int len, i, ret = 0; + + mutex_lock(&vi->i2c_lock); + vmsg = &vi->vmsg; + vmsg->buf = NULL; + + for (i = 0; i < num; i++) { + ret = virtio_i2c_add_msg(vq, vmsg, &msgs[i]); + if (ret) { + dev_err(&adap->dev, "failed to add msg[%d] to virtqueue.\n", i); + break; + } + + virtqueue_kick(vq); + + time_left = wait_for_completion_timeout(&vi->completion, adap->timeout); + if (!time_left) { + dev_err(&adap->dev, "msg[%d]: addr=0x%x timeout.\n", i, msgs[i].addr); + break; + } + + vmsg = (struct virtio_i2c_msg *)virtqueue_get_buf(vq, &len); + if (vmsg) { + /* vmsg should point to the same address with &vi->vmsg */ + if (vmsg != &vi->vmsg) { + dev_err(&adap->dev, "msg[%d]: addr=0x%x virtqueue error.\n", + i, le16_to_cpu(vmsg->hdr.addr)); + break; + } + if (vmsg->status != VIRTIO_I2C_MSG_OK) { + dev_err(&adap->dev, "msg[%d]: addr=0x%x error=%d.\n", + i, le16_to_cpu(vmsg->hdr.addr), vmsg->status); + break; + } + if ((msgs[i].flags & I2C_M_RD) && msgs[i].len) + memcpy(msgs[i].buf, vmsg->buf, msgs[i].len); + + kfree(vmsg->buf); + vmsg->buf = NULL; + } + + reinit_completion(&vi->completion); + } + + mutex_unlock(&vi->i2c_lock); + kfree(vmsg->buf); + return ((ret < 0) ? ret : i); +} + +static void virtio_i2c_del_vqs(struct virtio_device *vdev) +{ + vdev->config->reset(vdev); + vdev->config->del_vqs(vdev); +} + +static int virtio_i2c_setup_vqs(struct virtio_i2c *vi) +{ + struct virtio_device *vdev = vi->vdev; + + vi->vq = virtio_find_single_vq(vdev, virtio_i2c_msg_done, "msg"); + return PTR_ERR_OR_ZERO(vi->vq); +} + +static u32 virtio_i2c_func(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static struct i2c_algorithm virtio_algorithm = { + .master_xfer = virtio_i2c_xfer, + .functionality = virtio_i2c_func, +}; + +static struct i2c_adapter virtio_adapter = { + .owner = THIS_MODULE, + .name = "Virtio I2C Adapter", + .class = I2C_CLASS_DEPRECATED, + .algo = &virtio_algorithm, +}; + +static int virtio_i2c_probe(struct virtio_device *vdev) +{ + struct device *pdev = vdev->dev.parent; + struct virtio_i2c *vi; + int ret; + + vi = devm_kzalloc(&vdev->dev, sizeof(*vi), GFP_KERNEL); + if (!vi) + return -ENOMEM; + + vdev->priv = vi; + vi->vdev = vdev; + + mutex_init(&vi->i2c_lock); + init_completion(&vi->completion); + + ret = virtio_i2c_setup_vqs(vi); + if (ret) + return ret; + + vi->adap = virtio_adapter; + i2c_set_adapdata(&vi->adap, vi); + vi->adap.dev.parent = &vdev->dev; + /* Setup ACPI node for slave devices which will be probed through ACPI */ + ACPI_COMPANION_SET(&vi->adap.dev, ACPI_COMPANION(pdev)); + vi->adap.timeout = HZ / 10; + + ret = i2c_add_adapter(&vi->adap); + if (ret) { + virtio_i2c_del_vqs(vdev); + dev_err(&vdev->dev, "failed to add virtio-i2c adapter.\n"); + } + + return ret; +} + +static void virtio_i2c_remove(struct virtio_device *vdev) +{ + struct virtio_i2c *vi = vdev->priv; + + i2c_del_adapter(&vi->adap); + virtio_i2c_del_vqs(vdev); +} + +static struct virtio_device_id id_table[] = { + { VIRTIO_ID_I2C_ADPTER, VIRTIO_DEV_ANY_ID }, + {} +}; +MODULE_DEVICE_TABLE(virtio, id_table); + +static int __maybe_unused virtio_i2c_freeze(struct virtio_device *vdev) +{ + virtio_i2c_del_vqs(vdev); + return 0; +} + +static int __maybe_unused virtio_i2c_restore(struct virtio_device *vdev) +{ + return virtio_i2c_setup_vqs(vdev->priv); +} + +static struct virtio_driver virtio_i2c_driver = { + .id_table = id_table, + .probe = virtio_i2c_probe, + .remove = virtio_i2c_remove, + .driver = { + .name = "i2c_virtio", + }, +#ifdef CONFIG_PM_SLEEP + .freeze = virtio_i2c_freeze, + .restore = virtio_i2c_restore, +#endif +}; +module_virtio_driver(virtio_i2c_driver); + +MODULE_DESCRIPTION("Virtio i2c bus driver"); +MODULE_LICENSE("GPL"); diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h index b052355..398ef2d 100644 --- a/include/uapi/linux/virtio_ids.h +++ b/include/uapi/linux/virtio_ids.h @@ -48,5 +48,6 @@ #define VIRTIO_ID_FS 26 /* virtio filesystem */ #define VIRTIO_ID_PMEM 27 /* virtio pmem */ #define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */ +#define VIRTIO_ID_I2C_ADPTER 34 /* virtio i2c adpter */ #endif /* _LINUX_VIRTIO_IDS_H */ -- 2.7.4
Randy Dunlap
2020-Sep-11 03:53 UTC
[PATCH v2] i2c: virtio: add a virtio i2c frontend driver
On 9/10/20 8:48 PM, Jie Deng wrote:> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 293e7a0..70c8e30 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -21,6 +21,17 @@ config I2C_ALI1535 > This driver can also be built as a module. If so, the module > will be called i2c-ali1535. > > +config I2C_VIRTIO > + tristate "Virtio I2C Adapter" > + depends on VIRTIO > + help > + If you say yes to this option, support will be included for the virtio > + i2c adapter driver. The hardware can be emulated by any device modelI2C preferably> + software according to the virtio protocol. > + > + This driver can also be built as a module. If so, the module > + will be called i2c-virtio. > + > config I2C_ALI1563 > tristate "ALI 1563" > depends on PCIthanks. -- ~Randy
On 2020/9/11 11:53, Randy Dunlap wrote:> On 9/10/20 8:48 PM, Jie Deng wrote: >> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig >> index 293e7a0..70c8e30 100644 >> --- a/drivers/i2c/busses/Kconfig >> +++ b/drivers/i2c/busses/Kconfig >> @@ -21,6 +21,17 @@ config I2C_ALI1535 >> This driver can also be built as a module. If so, the module >> will be called i2c-ali1535. >> >> +config I2C_VIRTIO >> + tristate "Virtio I2C Adapter" >> + depends on VIRTIO >> + help >> + If you say yes to this option, support will be included for the virtio >> + i2c adapter driver. The hardware can be emulated by any device model > I2C > preferably >I will fix this typo. Thank you.>> + software according to the virtio protocol. >> + >> + This driver can also be built as a module. If so, the module >> + will be called i2c-virtio. >> + >> config I2C_ALI1563 >> tristate "ALI 1563" >> depends on PCI > > thanks.
On 2020/9/11 ??11:48, Jie Deng wrote:> Add an I2C bus driver for virtio para-virtualization. > > The controller can be emulated by the backend driver in > any device model software by following the virtio protocol. > > This driver communicates with the backend driver through a > virtio I2C message structure which includes following parts: > > - Header: i2c_msg addr, flags, len. > - Data buffer: the pointer to the I2C msg data. > - Status: the processing result from the backend. > > People may implement different backend drivers to emulate > different controllers according to their needs. A backend > example can be found in the device model of the open source > project ACRN. For more information, please refer to > https://projectacrn.org. > > The virtio device ID 34 is used for this I2C adpter since IDs > before 34 have been reserved by other virtio devices. > > Co-developed-by: Conghui Chen <conghui.chen at intel.com> > Signed-off-by: Conghui Chen <conghui.chen at intel.com> > Signed-off-by: Jie Deng <jie.deng at intel.com> > Reviewed-by: Shuo Liu <shuo.a.liu at intel.com> > Reviewed-by: Andy Shevchenko <andriy.shevchenko at linux.intel.com> > --- > The device ID request: > https://github.com/oasis-tcs/virtio-spec/issues/85 > > Changes in v2: > - Addressed comments received from Michael, Andy and Jason. > > drivers/i2c/busses/Kconfig | 11 ++ > drivers/i2c/busses/Makefile | 3 + > drivers/i2c/busses/i2c-virtio.c | 271 ++++++++++++++++++++++++++++++++++++++++ > include/uapi/linux/virtio_ids.h | 1 + > 4 files changed, 286 insertions(+) > create mode 100644 drivers/i2c/busses/i2c-virtio.c > > diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig > index 293e7a0..70c8e30 100644 > --- a/drivers/i2c/busses/Kconfig > +++ b/drivers/i2c/busses/Kconfig > @@ -21,6 +21,17 @@ config I2C_ALI1535 > This driver can also be built as a module. If so, the module > will be called i2c-ali1535. > > +config I2C_VIRTIO > + tristate "Virtio I2C Adapter" > + depends on VIRTIO > + help > + If you say yes to this option, support will be included for the virtio > + i2c adapter driver. The hardware can be emulated by any device model > + software according to the virtio protocol. > + > + This driver can also be built as a module. If so, the module > + will be called i2c-virtio. > + > config I2C_ALI1563 > tristate "ALI 1563" > depends on PCI > diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile > index 19aff0e..821acfa 100644 > --- a/drivers/i2c/busses/Makefile > +++ b/drivers/i2c/busses/Makefile > @@ -6,6 +6,9 @@ > # ACPI drivers > obj-$(CONFIG_I2C_SCMI) += i2c-scmi.o > > +# VIRTIO I2C host controller driver > +obj-$(CONFIG_I2C_VIRTIO) += i2c-virtio.o > + > # PC SMBus host controller drivers > obj-$(CONFIG_I2C_ALI1535) += i2c-ali1535.o > obj-$(CONFIG_I2C_ALI1563) += i2c-ali1563.o > diff --git a/drivers/i2c/busses/i2c-virtio.c b/drivers/i2c/busses/i2c-virtio.c > new file mode 100644 > index 0000000..aff1a9a > --- /dev/null > +++ b/drivers/i2c/busses/i2c-virtio.c > @@ -0,0 +1,271 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Virtio I2C Bus Driver > + * > + * Copyright (c) 2020 Intel Corporation. All rights reserved. > + */ > + > +#include <linux/acpi.h> > +#include <linux/completion.h> > +#include <linux/err.h> > +#include <linux/i2c.h> > +#include <linux/io.h> > +#include <linux/jiffies.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/platform_device.h> > +#include <linux/wait.h> > + > +#include <linux/virtio.h> > +#include <linux/virtio_ids.h> > +#include <linux/virtio_config.h> > + > +#define VIRTIO_I2C_MSG_OK 0 > +#define VIRTIO_I2C_MSG_ERR 1 > + > +/** > + * struct virtio_i2c_hdr - the virtio I2C message header structure > + * @addr: i2c_msg addr, the slave address > + * @flags: i2c_msg flags > + * @len: i2c_msg len > + */ > +struct virtio_i2c_hdr { > + __le16 addr; > + __le16 flags; > + __le16 len; > +};As said in v1, this should belong to uapi.> + > +/** > + * struct virtio_i2c_msg - the virtio I2C message structure > + * @hdr: the virtio I2C message header > + * @buf: virtio I2C message data buffer > + * @status: the processing result from the backend > + */ > +struct virtio_i2c_msg { > + struct virtio_i2c_hdr hdr; > + u8 *buf; > + u8 status; > +};I'm not quite sure this is the best layout. E.g virtio scsi differ in buffer out of out one: structvirtio_scsi_req_cmd{ ... u8 dataout[]; ... u8 datain[]; } And I would like to have a look at the spec patch. Thanks> + > +/** > + * struct virtio_i2c - virtio I2C data > + * @vdev: virtio device for this controller > + * @completion: completion of virtio I2C message > + * @vmsg: the virtio I2C message for communication > + * @adap: I2C adapter for this controller > + * @i2c_lock: lock for virtqueue processing > + * @vq: the virtio virtqueue for communication > + */ > +struct virtio_i2c { > + struct virtio_device *vdev; > + struct completion completion; > + struct virtio_i2c_msg vmsg; > + struct i2c_adapter adap; > + struct mutex i2c_lock; > + struct virtqueue *vq; > +}; > + > +static void virtio_i2c_msg_done(struct virtqueue *vq) > +{ > + struct virtio_i2c *vi = vq->vdev->priv; > + > + complete(&vi->completion); > +} > + > +static int virtio_i2c_add_msg(struct virtqueue *vq, > + struct virtio_i2c_msg *vmsg, > + struct i2c_msg *msg) > +{ > + struct scatterlist *sgs[3], hdr, bout, bin, status; > + int outcnt = 0, incnt = 0; > + > + if (!msg->len) > + return -EINVAL; > + > + vmsg->hdr.addr = cpu_to_le16(msg->addr); > + vmsg->hdr.flags = cpu_to_le16(msg->flags); > + vmsg->hdr.len = cpu_to_le16(msg->len); > + > + vmsg->buf = kzalloc(msg->len, GFP_KERNEL); > + if (!vmsg->buf) > + return -ENOMEM; > + > + sg_init_one(&hdr, &vmsg->hdr, sizeof(struct virtio_i2c_hdr)); > + sgs[outcnt++] = &hdr; > + if (msg->flags & I2C_M_RD) { > + sg_init_one(&bin, vmsg->buf, msg->len); > + sgs[outcnt + incnt++] = &bin; > + } else { > + memcpy(vmsg->buf, msg->buf, msg->len); > + sg_init_one(&bout, vmsg->buf, msg->len); > + sgs[outcnt++] = &bout; > + } > + sg_init_one(&status, &vmsg->status, sizeof(vmsg->status)); > + sgs[outcnt + incnt++] = &status; > + > + return virtqueue_add_sgs(vq, sgs, outcnt, incnt, vmsg, GFP_KERNEL); > +} > + > +static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) > +{ > + struct virtio_i2c *vi = i2c_get_adapdata(adap); > + struct virtqueue *vq = vi->vq; > + struct virtio_i2c_msg *vmsg; > + unsigned long time_left; > + int len, i, ret = 0; > + > + mutex_lock(&vi->i2c_lock); > + vmsg = &vi->vmsg; > + vmsg->buf = NULL; > + > + for (i = 0; i < num; i++) { > + ret = virtio_i2c_add_msg(vq, vmsg, &msgs[i]); > + if (ret) { > + dev_err(&adap->dev, "failed to add msg[%d] to virtqueue.\n", i); > + break; > + } > + > + virtqueue_kick(vq); > + > + time_left = wait_for_completion_timeout(&vi->completion, adap->timeout); > + if (!time_left) { > + dev_err(&adap->dev, "msg[%d]: addr=0x%x timeout.\n", i, msgs[i].addr); > + break; > + } > + > + vmsg = (struct virtio_i2c_msg *)virtqueue_get_buf(vq, &len); > + if (vmsg) { > + /* vmsg should point to the same address with &vi->vmsg */ > + if (vmsg != &vi->vmsg) { > + dev_err(&adap->dev, "msg[%d]: addr=0x%x virtqueue error.\n", > + i, le16_to_cpu(vmsg->hdr.addr)); > + break; > + } > + if (vmsg->status != VIRTIO_I2C_MSG_OK) { > + dev_err(&adap->dev, "msg[%d]: addr=0x%x error=%d.\n", > + i, le16_to_cpu(vmsg->hdr.addr), vmsg->status); > + break; > + } > + if ((msgs[i].flags & I2C_M_RD) && msgs[i].len) > + memcpy(msgs[i].buf, vmsg->buf, msgs[i].len); > + > + kfree(vmsg->buf); > + vmsg->buf = NULL; > + } > + > + reinit_completion(&vi->completion); > + } > + > + mutex_unlock(&vi->i2c_lock); > + kfree(vmsg->buf); > + return ((ret < 0) ? ret : i); > +} > + > +static void virtio_i2c_del_vqs(struct virtio_device *vdev) > +{ > + vdev->config->reset(vdev); > + vdev->config->del_vqs(vdev); > +} > + > +static int virtio_i2c_setup_vqs(struct virtio_i2c *vi) > +{ > + struct virtio_device *vdev = vi->vdev; > + > + vi->vq = virtio_find_single_vq(vdev, virtio_i2c_msg_done, "msg"); > + return PTR_ERR_OR_ZERO(vi->vq); > +} > + > +static u32 virtio_i2c_func(struct i2c_adapter *adap) > +{ > + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; > +} > + > +static struct i2c_algorithm virtio_algorithm = { > + .master_xfer = virtio_i2c_xfer, > + .functionality = virtio_i2c_func, > +}; > + > +static struct i2c_adapter virtio_adapter = { > + .owner = THIS_MODULE, > + .name = "Virtio I2C Adapter", > + .class = I2C_CLASS_DEPRECATED, > + .algo = &virtio_algorithm, > +}; > + > +static int virtio_i2c_probe(struct virtio_device *vdev) > +{ > + struct device *pdev = vdev->dev.parent; > + struct virtio_i2c *vi; > + int ret; > + > + vi = devm_kzalloc(&vdev->dev, sizeof(*vi), GFP_KERNEL); > + if (!vi) > + return -ENOMEM; > + > + vdev->priv = vi; > + vi->vdev = vdev; > + > + mutex_init(&vi->i2c_lock); > + init_completion(&vi->completion); > + > + ret = virtio_i2c_setup_vqs(vi); > + if (ret) > + return ret; > + > + vi->adap = virtio_adapter; > + i2c_set_adapdata(&vi->adap, vi); > + vi->adap.dev.parent = &vdev->dev; > + /* Setup ACPI node for slave devices which will be probed through ACPI */ > + ACPI_COMPANION_SET(&vi->adap.dev, ACPI_COMPANION(pdev)); > + vi->adap.timeout = HZ / 10; > + > + ret = i2c_add_adapter(&vi->adap); > + if (ret) { > + virtio_i2c_del_vqs(vdev); > + dev_err(&vdev->dev, "failed to add virtio-i2c adapter.\n"); > + } > + > + return ret; > +} > + > +static void virtio_i2c_remove(struct virtio_device *vdev) > +{ > + struct virtio_i2c *vi = vdev->priv; > + > + i2c_del_adapter(&vi->adap); > + virtio_i2c_del_vqs(vdev); > +} > + > +static struct virtio_device_id id_table[] = { > + { VIRTIO_ID_I2C_ADPTER, VIRTIO_DEV_ANY_ID }, > + {} > +}; > +MODULE_DEVICE_TABLE(virtio, id_table); > + > +static int __maybe_unused virtio_i2c_freeze(struct virtio_device *vdev) > +{ > + virtio_i2c_del_vqs(vdev); > + return 0; > +} > + > +static int __maybe_unused virtio_i2c_restore(struct virtio_device *vdev) > +{ > + return virtio_i2c_setup_vqs(vdev->priv); > +} > + > +static struct virtio_driver virtio_i2c_driver = { > + .id_table = id_table, > + .probe = virtio_i2c_probe, > + .remove = virtio_i2c_remove, > + .driver = { > + .name = "i2c_virtio", > + }, > +#ifdef CONFIG_PM_SLEEP > + .freeze = virtio_i2c_freeze, > + .restore = virtio_i2c_restore, > +#endif > +}; > +module_virtio_driver(virtio_i2c_driver); > + > +MODULE_DESCRIPTION("Virtio i2c bus driver"); > +MODULE_LICENSE("GPL"); > diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h > index b052355..398ef2d 100644 > --- a/include/uapi/linux/virtio_ids.h > +++ b/include/uapi/linux/virtio_ids.h > @@ -48,5 +48,6 @@ > #define VIRTIO_ID_FS 26 /* virtio filesystem */ > #define VIRTIO_ID_PMEM 27 /* virtio pmem */ > #define VIRTIO_ID_MAC80211_HWSIM 29 /* virtio mac80211-hwsim */ > +#define VIRTIO_ID_I2C_ADPTER 34 /* virtio i2c adpter */ > > #endif /* _LINUX_VIRTIO_IDS_H */
On 2020/9/14 10:46, Jason Wang wrote:> >> + >> +#define VIRTIO_I2C_MSG_OK??? 0 >> +#define VIRTIO_I2C_MSG_ERR??? 1 >> + >> +/** >> + * struct virtio_i2c_hdr - the virtio I2C message header structure >> + * @addr: i2c_msg addr, the slave address >> + * @flags: i2c_msg flags >> + * @len: i2c_msg len >> + */ >> +struct virtio_i2c_hdr { >> +??? __le16 addr; >> +??? __le16 flags; >> +??? __le16 len; >> +}; > > > As said in v1, this should belong to uapi. >That's right. I missed this. I will move these things to uapi. Thanks.> >> + >> +/** >> + * struct virtio_i2c_msg - the virtio I2C message structure >> + * @hdr: the virtio I2C message header >> + * @buf: virtio I2C message data buffer >> + * @status: the processing result from the backend >> + */ >> +struct virtio_i2c_msg { >> +??? struct virtio_i2c_hdr hdr; >> +??? u8 *buf; >> +??? u8 status; >> +}; > > > I'm not quite sure this is the best layout. > > E.g virtio scsi differ in buffer out of out one: > > structvirtio_scsi_req_cmd{ > ... > u8 dataout[]; > ... > u8 datain[]; > > } > > And I would like to have a look at the spec patch. > > Thanks >Sure. I will send the v3 along with the spec patch. Thanks.
Dan Carpenter
2020-Sep-14 14:48 UTC
[PATCH v2] i2c: virtio: add a virtio i2c frontend driver
Hi Jie, url: https://github.com/0day-ci/linux/commits/Jie-Deng/i2c-virtio-add-a-virtio-i2c-frontend-driver/20200911-115013 base: https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/for-next config: parisc-randconfig-m031-20200913 (attached as .config) compiler: hppa-linux-gcc (GCC) 9.3.0 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp at intel.com> Reported-by: Dan Carpenter <dan.carpenter at oracle.com> smatch warnings: drivers/i2c/busses/i2c-virtio.c:160 virtio_i2c_xfer() error: we previously assumed 'vmsg' could be null (see line 137) # https://github.com/0day-ci/linux/commit/0a54ec771966748fcbc86256b830b5f786168b7d git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Jie-Deng/i2c-virtio-add-a-virtio-i2c-frontend-driver/20200911-115013 git checkout 0a54ec771966748fcbc86256b830b5f786168b7d vim +/vmsg +160 drivers/i2c/busses/i2c-virtio.c 0a54ec77196674 Jie Deng 2020-09-11 109 static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) 0a54ec77196674 Jie Deng 2020-09-11 110 { 0a54ec77196674 Jie Deng 2020-09-11 111 struct virtio_i2c *vi = i2c_get_adapdata(adap); 0a54ec77196674 Jie Deng 2020-09-11 112 struct virtqueue *vq = vi->vq; 0a54ec77196674 Jie Deng 2020-09-11 113 struct virtio_i2c_msg *vmsg; 0a54ec77196674 Jie Deng 2020-09-11 114 unsigned long time_left; 0a54ec77196674 Jie Deng 2020-09-11 115 int len, i, ret = 0; 0a54ec77196674 Jie Deng 2020-09-11 116 0a54ec77196674 Jie Deng 2020-09-11 117 mutex_lock(&vi->i2c_lock); 0a54ec77196674 Jie Deng 2020-09-11 118 vmsg = &vi->vmsg; 0a54ec77196674 Jie Deng 2020-09-11 119 vmsg->buf = NULL; 0a54ec77196674 Jie Deng 2020-09-11 120 0a54ec77196674 Jie Deng 2020-09-11 121 for (i = 0; i < num; i++) { 0a54ec77196674 Jie Deng 2020-09-11 122 ret = virtio_i2c_add_msg(vq, vmsg, &msgs[i]); 0a54ec77196674 Jie Deng 2020-09-11 123 if (ret) { 0a54ec77196674 Jie Deng 2020-09-11 124 dev_err(&adap->dev, "failed to add msg[%d] to virtqueue.\n", i); 0a54ec77196674 Jie Deng 2020-09-11 125 break; 0a54ec77196674 Jie Deng 2020-09-11 126 } 0a54ec77196674 Jie Deng 2020-09-11 127 0a54ec77196674 Jie Deng 2020-09-11 128 virtqueue_kick(vq); 0a54ec77196674 Jie Deng 2020-09-11 129 0a54ec77196674 Jie Deng 2020-09-11 130 time_left = wait_for_completion_timeout(&vi->completion, adap->timeout); 0a54ec77196674 Jie Deng 2020-09-11 131 if (!time_left) { 0a54ec77196674 Jie Deng 2020-09-11 132 dev_err(&adap->dev, "msg[%d]: addr=0x%x timeout.\n", i, msgs[i].addr); 0a54ec77196674 Jie Deng 2020-09-11 133 break; 0a54ec77196674 Jie Deng 2020-09-11 134 } 0a54ec77196674 Jie Deng 2020-09-11 135 0a54ec77196674 Jie Deng 2020-09-11 136 vmsg = (struct virtio_i2c_msg *)virtqueue_get_buf(vq, &len); 0a54ec77196674 Jie Deng 2020-09-11 @137 if (vmsg) { ^^^^ Check for NULL. 0a54ec77196674 Jie Deng 2020-09-11 138 /* vmsg should point to the same address with &vi->vmsg */ 0a54ec77196674 Jie Deng 2020-09-11 139 if (vmsg != &vi->vmsg) { 0a54ec77196674 Jie Deng 2020-09-11 140 dev_err(&adap->dev, "msg[%d]: addr=0x%x virtqueue error.\n", 0a54ec77196674 Jie Deng 2020-09-11 141 i, le16_to_cpu(vmsg->hdr.addr)); 0a54ec77196674 Jie Deng 2020-09-11 142 break; 0a54ec77196674 Jie Deng 2020-09-11 143 } 0a54ec77196674 Jie Deng 2020-09-11 144 if (vmsg->status != VIRTIO_I2C_MSG_OK) { 0a54ec77196674 Jie Deng 2020-09-11 145 dev_err(&adap->dev, "msg[%d]: addr=0x%x error=%d.\n", 0a54ec77196674 Jie Deng 2020-09-11 146 i, le16_to_cpu(vmsg->hdr.addr), vmsg->status); 0a54ec77196674 Jie Deng 2020-09-11 147 break; 0a54ec77196674 Jie Deng 2020-09-11 148 } 0a54ec77196674 Jie Deng 2020-09-11 149 if ((msgs[i].flags & I2C_M_RD) && msgs[i].len) 0a54ec77196674 Jie Deng 2020-09-11 150 memcpy(msgs[i].buf, vmsg->buf, msgs[i].len); 0a54ec77196674 Jie Deng 2020-09-11 151 0a54ec77196674 Jie Deng 2020-09-11 152 kfree(vmsg->buf); 0a54ec77196674 Jie Deng 2020-09-11 153 vmsg->buf = NULL; 0a54ec77196674 Jie Deng 2020-09-11 154 } 0a54ec77196674 Jie Deng 2020-09-11 155 0a54ec77196674 Jie Deng 2020-09-11 156 reinit_completion(&vi->completion); 0a54ec77196674 Jie Deng 2020-09-11 157 } 0a54ec77196674 Jie Deng 2020-09-11 158 0a54ec77196674 Jie Deng 2020-09-11 159 mutex_unlock(&vi->i2c_lock); 0a54ec77196674 Jie Deng 2020-09-11 @160 kfree(vmsg->buf); ^^^^^^^^^ Unchecked dereference. 0a54ec77196674 Jie Deng 2020-09-11 161 return ((ret < 0) ? ret : i); 0a54ec77196674 Jie Deng 2020-09-11 162 } --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all at lists.01.org -------------- next part -------------- A non-text attachment was scrubbed... Name: .config.gz Type: application/gzip Size: 28062 bytes Desc: not available URL: <http://lists.linuxfoundation.org/pipermail/virtualization/attachments/20200914/3bdd60e8/attachment-0001.gz>
Andy Shevchenko
2020-Sep-14 15:24 UTC
[PATCH v2] i2c: virtio: add a virtio i2c frontend driver
On Mon, Sep 14, 2020 at 05:48:07PM +0300, Dan Carpenter wrote:> Hi Jie, > > url: https://github.com/0day-ci/linux/commits/Jie-Deng/i2c-virtio-add-a-virtio-i2c-frontend-driver/20200911-115013 > base: https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git i2c/for-next > config: parisc-randconfig-m031-20200913 (attached as .config) > compiler: hppa-linux-gcc (GCC) 9.3.0 > > If you fix the issue, kindly add following tag as appropriate > Reported-by: kernel test robot <lkp at intel.com> > Reported-by: Dan Carpenter <dan.carpenter at oracle.com> > > smatch warnings: > drivers/i2c/busses/i2c-virtio.c:160 virtio_i2c_xfer() error: we previously assumed 'vmsg' could be null (see line 137) >It's quite possible a false positive. Look at 122. But I agree that for-loop is not the best for such things to understand. Perhaps switching to do {} while () will make it better.> # https://github.com/0day-ci/linux/commit/0a54ec771966748fcbc86256b830b5f786168b7d > git remote add linux-review https://github.com/0day-ci/linux > git fetch --no-tags linux-review Jie-Deng/i2c-virtio-add-a-virtio-i2c-frontend-driver/20200911-115013 > git checkout 0a54ec771966748fcbc86256b830b5f786168b7d > vim +/vmsg +160 drivers/i2c/busses/i2c-virtio.c > > 0a54ec77196674 Jie Deng 2020-09-11 109 static int virtio_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) > 0a54ec77196674 Jie Deng 2020-09-11 110 { > 0a54ec77196674 Jie Deng 2020-09-11 111 struct virtio_i2c *vi = i2c_get_adapdata(adap); > 0a54ec77196674 Jie Deng 2020-09-11 112 struct virtqueue *vq = vi->vq; > 0a54ec77196674 Jie Deng 2020-09-11 113 struct virtio_i2c_msg *vmsg; > 0a54ec77196674 Jie Deng 2020-09-11 114 unsigned long time_left; > 0a54ec77196674 Jie Deng 2020-09-11 115 int len, i, ret = 0; > 0a54ec77196674 Jie Deng 2020-09-11 116 > 0a54ec77196674 Jie Deng 2020-09-11 117 mutex_lock(&vi->i2c_lock); > 0a54ec77196674 Jie Deng 2020-09-11 118 vmsg = &vi->vmsg; > 0a54ec77196674 Jie Deng 2020-09-11 119 vmsg->buf = NULL; > 0a54ec77196674 Jie Deng 2020-09-11 120 > 0a54ec77196674 Jie Deng 2020-09-11 121 for (i = 0; i < num; i++) { > 0a54ec77196674 Jie Deng 2020-09-11 122 ret = virtio_i2c_add_msg(vq, vmsg, &msgs[i]); > 0a54ec77196674 Jie Deng 2020-09-11 123 if (ret) { > 0a54ec77196674 Jie Deng 2020-09-11 124 dev_err(&adap->dev, "failed to add msg[%d] to virtqueue.\n", i); > 0a54ec77196674 Jie Deng 2020-09-11 125 break; > 0a54ec77196674 Jie Deng 2020-09-11 126 } > 0a54ec77196674 Jie Deng 2020-09-11 127 > 0a54ec77196674 Jie Deng 2020-09-11 128 virtqueue_kick(vq); > 0a54ec77196674 Jie Deng 2020-09-11 129 > 0a54ec77196674 Jie Deng 2020-09-11 130 time_left = wait_for_completion_timeout(&vi->completion, adap->timeout); > 0a54ec77196674 Jie Deng 2020-09-11 131 if (!time_left) { > 0a54ec77196674 Jie Deng 2020-09-11 132 dev_err(&adap->dev, "msg[%d]: addr=0x%x timeout.\n", i, msgs[i].addr); > 0a54ec77196674 Jie Deng 2020-09-11 133 break; > 0a54ec77196674 Jie Deng 2020-09-11 134 } > 0a54ec77196674 Jie Deng 2020-09-11 135 > 0a54ec77196674 Jie Deng 2020-09-11 136 vmsg = (struct virtio_i2c_msg *)virtqueue_get_buf(vq, &len); > 0a54ec77196674 Jie Deng 2020-09-11 @137 if (vmsg) { > ^^^^ > Check for NULL. > > 0a54ec77196674 Jie Deng 2020-09-11 138 /* vmsg should point to the same address with &vi->vmsg */ > 0a54ec77196674 Jie Deng 2020-09-11 139 if (vmsg != &vi->vmsg) { > 0a54ec77196674 Jie Deng 2020-09-11 140 dev_err(&adap->dev, "msg[%d]: addr=0x%x virtqueue error.\n", > 0a54ec77196674 Jie Deng 2020-09-11 141 i, le16_to_cpu(vmsg->hdr.addr)); > 0a54ec77196674 Jie Deng 2020-09-11 142 break; > 0a54ec77196674 Jie Deng 2020-09-11 143 } > 0a54ec77196674 Jie Deng 2020-09-11 144 if (vmsg->status != VIRTIO_I2C_MSG_OK) { > 0a54ec77196674 Jie Deng 2020-09-11 145 dev_err(&adap->dev, "msg[%d]: addr=0x%x error=%d.\n", > 0a54ec77196674 Jie Deng 2020-09-11 146 i, le16_to_cpu(vmsg->hdr.addr), vmsg->status); > 0a54ec77196674 Jie Deng 2020-09-11 147 break; > 0a54ec77196674 Jie Deng 2020-09-11 148 } > 0a54ec77196674 Jie Deng 2020-09-11 149 if ((msgs[i].flags & I2C_M_RD) && msgs[i].len) > 0a54ec77196674 Jie Deng 2020-09-11 150 memcpy(msgs[i].buf, vmsg->buf, msgs[i].len); > 0a54ec77196674 Jie Deng 2020-09-11 151 > 0a54ec77196674 Jie Deng 2020-09-11 152 kfree(vmsg->buf); > 0a54ec77196674 Jie Deng 2020-09-11 153 vmsg->buf = NULL; > 0a54ec77196674 Jie Deng 2020-09-11 154 } > 0a54ec77196674 Jie Deng 2020-09-11 155 > 0a54ec77196674 Jie Deng 2020-09-11 156 reinit_completion(&vi->completion); > 0a54ec77196674 Jie Deng 2020-09-11 157 } > 0a54ec77196674 Jie Deng 2020-09-11 158 > 0a54ec77196674 Jie Deng 2020-09-11 159 mutex_unlock(&vi->i2c_lock); > 0a54ec77196674 Jie Deng 2020-09-11 @160 kfree(vmsg->buf); > ^^^^^^^^^ > Unchecked dereference. > > 0a54ec77196674 Jie Deng 2020-09-11 161 return ((ret < 0) ? ret : i); > 0a54ec77196674 Jie Deng 2020-09-11 162 } > > --- > 0-DAY CI Kernel Test Service, Intel Corporation > https://lists.01.org/hyperkitty/list/kbuild-all at lists.01.org-- With Best Regards, Andy Shevchenko
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