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SubjectRe: [PATCH V2 1/1] Drivers: input: serio: New driver to support Hyper-V synthetic keyboard
Hi K.Y.,

On Tue, Sep 17, 2013 at 04:26:58PM -0700, K. Y. Srinivasan wrote:
> Add a new driver to support synthetic keyboard. On the next generation
> Hyper-V guest firmware, many legacy devices will not be emulated and this
> driver will be required.
>
> I would like to thank Vojtech Pavlik <vojtech@suse.cz> for helping me with the
> details of the AT keyboard driver. I would also like to thank
> Dan Carpenter <dan.carpenter@oracle.com> and
> Dmitry Torokhov <dmitry.torokhov@gmail.com> for their detailed review of this
> driver.
>
> I have addressed all the comments of Dan and Dmitry in this version of
> the patch

This looks much better. Could you tell me if the patch below (on top of
yours) still works?

Thanks.

--
Dmitry

Input: hyperv-keyboard - misc changes

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---
drivers/input/serio/Kconfig | 3
drivers/input/serio/hyperv-keyboard.c | 378 ++++++++++++++++++---------------
2 files changed, 208 insertions(+), 173 deletions(-)

diff --git a/drivers/input/serio/Kconfig b/drivers/input/serio/Kconfig
index f3996e7..a5f342e 100644
--- a/drivers/input/serio/Kconfig
+++ b/drivers/input/serio/Kconfig
@@ -274,4 +274,7 @@ config HYPERV_KEYBOARD
help
Select this option to enable the Hyper-V Keyboard driver.

+ To compile this driver as a module, choose M here: the module will
+ be called hyperv_keyboard.
+
endif
diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
index c327a18..401fbdd 100644
--- a/drivers/input/serio/hyperv-keyboard.c
+++ b/drivers/input/serio/hyperv-keyboard.c
@@ -10,6 +10,7 @@
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*/
+
#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
@@ -42,20 +43,16 @@ enum synth_kbd_msg_type {
* Basic message structures.
*/
struct synth_kbd_msg_hdr {
- u32 type;
+ __le32 type;
};

struct synth_kbd_msg {
struct synth_kbd_msg_hdr header;
- char data[1]; /* Enclosed message */
+ char data[]; /* Enclosed message */
};

union synth_kbd_version {
- struct {
- u16 minor_version;
- u16 major_version;
- };
- u32 version;
+ __le32 version;
};

/*
@@ -78,8 +75,8 @@ struct synth_kbd_protocol_response {
#define IS_E1 BIT(3)
struct synth_kbd_keystroke {
struct synth_kbd_msg_hdr header;
- u16 make_code;
- u16 reserved0;
+ __le16 make_code;
+ __le16 reserved0;
__le32 info; /* Additional information */
};

@@ -98,58 +95,27 @@ struct synth_kbd_keystroke {
* Represents a keyboard device
*/
struct hv_kbd_dev {
- struct hv_device *device;
+ struct hv_device *hv_dev;
+ struct serio *hv_serio;
struct synth_kbd_protocol_request protocol_req;
struct synth_kbd_protocol_response protocol_resp;
/* Synchronize the request/response if needed */
- struct completion wait_event;
- struct serio *hv_serio;
+ struct completion wait_event;
+ spinlock_t lock; /* protects 'started' field */
+ bool started;
};

-
-static struct hv_kbd_dev *hv_kbd_alloc_device(struct hv_device *device)
-{
- struct hv_kbd_dev *kbd_dev;
- struct serio *hv_serio;
-
- kbd_dev = kzalloc(sizeof(struct hv_kbd_dev), GFP_KERNEL);
- if (!kbd_dev)
- return NULL;
- hv_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
- if (hv_serio == NULL) {
- kfree(kbd_dev);
- return NULL;
- }
- hv_serio->id.type = SERIO_8042_XL;
- strlcpy(hv_serio->name, dev_name(&device->device),
- sizeof(hv_serio->name));
- strlcpy(hv_serio->phys, dev_name(&device->device),
- sizeof(hv_serio->phys));
- hv_serio->dev.parent = &device->device;
- kbd_dev->device = device;
- kbd_dev->hv_serio = hv_serio;
- hv_set_drvdata(device, kbd_dev);
- init_completion(&kbd_dev->wait_event);
-
- return kbd_dev;
-}
-
-static void hv_kbd_free_device(struct hv_kbd_dev *device)
-{
- serio_unregister_port(device->hv_serio);
- hv_set_drvdata(device->device, NULL);
- kfree(device);
-}
-
-static void hv_kbd_on_receive(struct hv_device *device,
- struct synth_kbd_msg *msg, u32 msg_length)
+static void hv_kbd_on_receive(struct hv_device *hv_dev,
+ struct synth_kbd_msg *msg, u32 msg_length)
{
- struct hv_kbd_dev *kbd_dev = hv_get_drvdata(device);
+ struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
struct synth_kbd_keystroke *ks_msg;
- u16 scan_code;
+ unsigned long flags;
+ u32 msg_type = __le32_to_cpu(msg->header.type);
u32 info;
+ u16 scan_code;

- switch (msg->header.type) {
+ switch (msg_type) {
case SYNTH_KBD_PROTOCOL_RESPONSE:
/*
* Validate the information provided by the host.
@@ -158,13 +124,17 @@ static void hv_kbd_on_receive(struct hv_device *device,
* goes away).
*/
if (msg_length < sizeof(struct synth_kbd_protocol_response)) {
- pr_err("Illegal protocol response packet\n");
+ dev_err(&hv_dev->device,
+ "Illegal protocol response packet (len: %d)\n",
+ msg_length);
break;
}
+
memcpy(&kbd_dev->protocol_resp, msg,
sizeof(struct synth_kbd_protocol_response));
complete(&kbd_dev->wait_event);
break;
+
case SYNTH_KBD_EVENT:
/*
* Validate the information provided by the host.
@@ -173,105 +143,122 @@ static void hv_kbd_on_receive(struct hv_device *device,
* goes away).
*/
if (msg_length < sizeof(struct synth_kbd_keystroke)) {
- pr_err("Illegal keyboard event packet\n");
+ dev_err(&hv_dev->device,
+ "Illegal keyboard event packet (len: %d)\n",
+ msg_length);
break;
}
+
ks_msg = (struct synth_kbd_keystroke *)msg;
- scan_code = ks_msg->make_code;
info = __le32_to_cpu(ks_msg->info);

/*
* Inject the information through the serio interrupt.
*/
- if (info & IS_E0)
- serio_interrupt(kbd_dev->hv_serio, XTKBD_EMUL0, 0);
- serio_interrupt(kbd_dev->hv_serio,
- scan_code | ((info & IS_BREAK) ?
- XTKBD_RELEASE : 0),
- 0);
+ spin_lock_irqsave(&kbd_dev->lock, flags);
+ if (kbd_dev->started) {
+ if (info & IS_E0)
+ serio_interrupt(kbd_dev->hv_serio,
+ XTKBD_EMUL0, 0);
+
+ scan_code = __le16_to_cpu(ks_msg->make_code);
+ if (info & IS_BREAK)
+ scan_code |= XTKBD_RELEASE;
+
+ serio_interrupt(kbd_dev->hv_serio, scan_code, 0);
+ }
+ spin_unlock_irqrestore(&kbd_dev->lock, flags);
+ break;
+
+ default:
+ dev_err(&hv_dev->device,
+ "unhandled message type %d\n", msg_type);
+ }
+}
+
+static void hv_kbd_handle_received_packet(struct hv_device *hv_dev,
+ struct vmpacket_descriptor *desc,
+ u32 bytes_recvd,
+ u64 req_id)
+{
+ struct synth_kbd_msg *msg;
+ u32 msg_sz;
+
+ switch (desc->type) {
+ case VM_PKT_COMP:
+ break;
+
+ case VM_PKT_DATA_INBAND:
+ /*
+ * We have a packet that has "inband" data. The API used
+ * for retrieving the packet guarantees that the complete
+ * packet is read. So, minimally, we should be able to
+ * parse the payload header safely (assuming that the host
+ * can be trusted. Trusting the host seems to be a
+ * reasonable assumption because in a virtualized
+ * environment there is not whole lot you can do if you
+ * don't trust the host.
+ *
+ * Nonetheless, let us validate if the host can be trusted
+ * (in a trivial way). The interesting aspect of this
+ * validation is how do you recover if we discover that the
+ * host is not to be trusted? Simply dropping the packet, I
+ * don't think is an appropriate recovery. In the interest
+ * of failing fast, it may be better to crash the guest.
+ * For now, I will just drop the packet!
+ */
+
+ msg_sz = bytes_recvd - (desc->offset8 << 3);
+ if (msg_sz <= sizeof(struct synth_kbd_msg_hdr)) {
+ /*
+ * Drop the packet and hope
+ * the problem magically goes away.
+ */
+ dev_err(&hv_dev->device,
+ "Illegal packet (type: %d, tid: %llx, size: %d)\n",
+ desc->type, req_id, msg_sz);
+ break;
+ }
+
+ msg = (void *)desc + (desc->offset8 << 3);
+ hv_kbd_on_receive(hv_dev, msg, msg_sz);
break;
+
default:
- pr_err("unhandled message type %d\n", msg->header.type);
+ dev_err(&hv_dev->device,
+ "unhandled packet type %d, tid %llx len %d\n",
+ desc->type, req_id, bytes_recvd);
+ break;
}
}

static void hv_kbd_on_channel_callback(void *context)
{
- const int packet_size = 0x100;
- int ret;
- struct hv_device *device = context;
+ struct hv_device *hv_dev = context;
+ void *buffer;
+ int bufferlen = 0x100; /* Start with sensible size */
u32 bytes_recvd;
u64 req_id;
- struct vmpacket_descriptor *desc;
- struct synth_kbd_msg *msg;
- int hdr_sz = sizeof(struct synth_kbd_msg);
- int msg_sz;
- unsigned char *buffer;
- int bufferlen = packet_size;
+ int error;

buffer = kmalloc(bufferlen, GFP_ATOMIC);
if (!buffer)
return;

while (1) {
- ret = vmbus_recvpacket_raw(device->channel, buffer,
- bufferlen, &bytes_recvd, &req_id);
-
- switch (ret) {
+ error = vmbus_recvpacket_raw(hv_dev->channel, buffer, bufferlen,
+ &bytes_recvd, &req_id);
+ switch (error) {
case 0:
if (bytes_recvd == 0) {
kfree(buffer);
return;
}
- desc = (struct vmpacket_descriptor *)buffer;
- switch (desc->type) {
- case VM_PKT_COMP:
- break;
- case VM_PKT_DATA_INBAND:
- /*
- * We have a packet that has "inband"
- * data. The API used for retrieving the
- * packet guarantees that the complete
- * packet is read. So, minimally, we should
- * be able to parse the payload header
- * safely (assuming that the host can be
- * trusted. Trusting the host seems to be a
- * reasonable assumption because in a
- * virtualized environment there is not whole
- * lot you can do if you don't trust the host.
- *
- * Nonetheless, let us validate if the host can
- * be trusted (in a trivial way).
- * The intresting aspect of this
- * validation is how do you recover if we
- * discover that the host is not to be
- * trusted? Simply dropping the packet, I
- * don't think is an appropriate recovery.
- * In the interest of failing fast, it may
- * be better to crash the guest. For now,
- * I will just drop the packet!
- */
- msg_sz = bytes_recvd - (desc->offset8 << 3);
- if (msg_sz < hdr_sz) {
- /*
- * Drop the packet and hope
- * the problem magically goes away.
- */
- pr_err("Illegal packet\n");
- break;
- }
-
- msg = (struct synth_kbd_msg *)
- ((unsigned long)desc +
- (desc->offset8 << 3));
- hv_kbd_on_receive(device, msg, (u32)msg_sz);
- break;
- default:
- pr_err("unhandled packet type %d, tid %llx len %d\n",
- desc->type, req_id, bytes_recvd);
- break;
- }
+
+ hv_kbd_handle_received_packet(hv_dev, buffer,
+ bytes_recvd, req_id);
break;
+
case -ENOBUFS:
kfree(buffer);
/* Handle large packet */
@@ -284,83 +271,128 @@ static void hv_kbd_on_channel_callback(void *context)
}
}

-static int hv_kbd_connect_to_vsp(struct hv_device *device)
+static int hv_kbd_connect_to_vsp(struct hv_device *hv_dev)
{
- int ret;
- int t;
- u32 proto_status;
- struct hv_kbd_dev *kbd_dev = hv_get_drvdata(device);
+ struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
struct synth_kbd_protocol_request *request;
struct synth_kbd_protocol_response *response;
+ u32 proto_status;
+ int error;

request = &kbd_dev->protocol_req;
memset(request, 0, sizeof(struct synth_kbd_protocol_request));
- request->header.type = SYNTH_KBD_PROTOCOL_REQUEST;
- request->version_requested.version = SYNTH_KBD_VERSION;
-
- ret = vmbus_sendpacket(device->channel, request,
- sizeof(struct synth_kbd_protocol_request),
- (unsigned long)request,
- VM_PKT_DATA_INBAND,
- VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
- if (ret)
- return ret;
-
- t = wait_for_completion_timeout(&kbd_dev->wait_event, 10 * HZ);
- if (!t)
+ request->header.type = cpu_to_le32(SYNTH_KBD_PROTOCOL_REQUEST);
+ request->version_requested.version = cpu_to_le32(SYNTH_KBD_VERSION);
+
+ error = vmbus_sendpacket(hv_dev->channel, request,
+ sizeof(struct synth_kbd_protocol_request),
+ (unsigned long)request,
+ VM_PKT_DATA_INBAND,
+ VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+ if (error)
+ return error;
+
+ if (!wait_for_completion_timeout(&kbd_dev->wait_event, 10 * HZ))
return -ETIMEDOUT;

response = &kbd_dev->protocol_resp;
proto_status = __le32_to_cpu(response->proto_status);
if (!(proto_status & PROTOCOL_ACCEPTED)) {
- pr_err("synth_kbd protocol request failed (version %d)\n",
- SYNTH_KBD_VERSION);
+ dev_err(&hv_dev->device,
+ "synth_kbd protocol request failed (version %d)\n",
+ SYNTH_KBD_VERSION);
return -ENODEV;
}
+
+ return 0;
+}
+
+static int hv_kbd_start(struct serio *serio)
+{
+ struct hv_kbd_dev *kbd_dev = serio->port_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&kbd_dev->lock, flags);
+ kbd_dev->started = true;
+ spin_unlock_irqrestore(&kbd_dev->lock, flags);
+
return 0;
}

-static int hv_kbd_probe(struct hv_device *device,
+static void hv_kbd_stop(struct serio *serio)
+{
+ struct hv_kbd_dev *kbd_dev = serio->port_data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&kbd_dev->lock, flags);
+ kbd_dev->started = false;
+ spin_unlock_irqrestore(&kbd_dev->lock, flags);
+}
+
+static int hv_kbd_probe(struct hv_device *hv_dev,
const struct hv_vmbus_device_id *dev_id)
{
- int ret;
struct hv_kbd_dev *kbd_dev;
+ struct serio *hv_serio;
+ int error;

- kbd_dev = hv_kbd_alloc_device(device);
- if (!kbd_dev)
- return -ENOMEM;
- ret = vmbus_open(device->channel,
- KBD_VSC_SEND_RING_BUFFER_SIZE,
- KBD_VSC_RECV_RING_BUFFER_SIZE,
- NULL,
- 0,
- hv_kbd_on_channel_callback,
- device
- );
-
- if (ret)
- goto probe_open_err;
- ret = hv_kbd_connect_to_vsp(device);
- if (ret)
- goto probe_connect_err;
- serio_register_port(kbd_dev->hv_serio);
- return ret;
+ kbd_dev = kzalloc(sizeof(struct hv_kbd_dev), GFP_KERNEL);
+ hv_serio = kzalloc(sizeof(struct serio), GFP_KERNEL);
+ if (!kbd_dev || !hv_serio) {
+ error = -ENOMEM;
+ goto err_free_mem;
+ }

-probe_connect_err:
- vmbus_close(device->channel);
+ kbd_dev->hv_dev = hv_dev;
+ kbd_dev->hv_serio = hv_serio;
+ spin_lock_init(&kbd_dev->lock);
+ init_completion(&kbd_dev->wait_event);
+ hv_set_drvdata(hv_dev, kbd_dev);

-probe_open_err:
- hv_kbd_free_device(kbd_dev);
+ hv_serio->dev.parent = &hv_dev->device;
+ hv_serio->id.type = SERIO_8042_XL;
+ strlcpy(hv_serio->name, dev_name(&hv_dev->device),
+ sizeof(hv_serio->name));
+ strlcpy(hv_serio->phys, dev_name(&hv_dev->device),
+ sizeof(hv_serio->phys));
+
+ hv_serio->start = hv_kbd_start;
+ hv_serio->stop = hv_kbd_stop;
+
+ error = vmbus_open(hv_dev->channel,
+ KBD_VSC_SEND_RING_BUFFER_SIZE,
+ KBD_VSC_RECV_RING_BUFFER_SIZE,
+ NULL, 0,
+ hv_kbd_on_channel_callback,
+ hv_dev);
+ if (error)
+ goto err_free_mem;
+
+ error = hv_kbd_connect_to_vsp(hv_dev);
+ if (error)
+ goto err_close_vmbus;

- return ret;
+ serio_register_port(kbd_dev->hv_serio);
+ return 0;
+
+err_close_vmbus:
+ vmbus_close(hv_dev->channel);
+err_free_mem:
+ kfree(hv_serio);
+ kfree(kbd_dev);
+ return error;
}

-static int hv_kbd_remove(struct hv_device *dev)
+static int hv_kbd_remove(struct hv_device *hv_dev)
{
- struct hv_kbd_dev *kbd_dev = hv_get_drvdata(dev);
+ struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
+
+ serio_unregister_port(kbd_dev->hv_serio);
+ vmbus_close(hv_dev->channel);
+ kfree(kbd_dev);
+
+ hv_set_drvdata(hv_dev, NULL);

- vmbus_close(dev->channel);
- hv_kbd_free_device(kbd_dev);
return 0;
}


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