linux.kernel - 26 new messages in 13 topics - digest

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http://groups.google.com/group/linux.kernel?hl=en

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Today's topics:

* clk: Allow drivers to pass in a regmap - 1 messages, 1 author
http://groups.google.com/group/linux.kernel/t/e089bad72bfa5919?hl=en
* Tegra baseline test results for v3.13-rc8 - 1 messages, 1 author
http://groups.google.com/group/linux.kernel/t/787a0b232eb0cfdb?hl=en
* next bio iters break discard? - 2 messages, 2 authors
http://groups.google.com/group/linux.kernel/t/df8973f865430413?hl=en
* Drivers: hv: Implement the file copy service - 1 messages, 1 author
http://groups.google.com/group/linux.kernel/t/e6745e5c9e6c7e65?hl=en
* timers: Reduce __run_timers() latency for empty list - 4 messages, 1 author
http://groups.google.com/group/linux.kernel/t/9be12def62cea4b8?hl=en
* [PATCH] ACPI / init: Run acpi_early_init() before efi_enter_virtual_mode() (
was: Re: [RFC PATCH 00/14] Support timezone of ACPI TAD and EFI TIME) - 1
messages, 1 author
http://groups.google.com/group/linux.kernel/t/09f3287b564cd53c?hl=en
* : KGDB/KDB/UV updates. - 4 messages, 1 author
http://groups.google.com/group/linux.kernel/t/49c736b07b53b058?hl=en
* perf report: Add report.percentage config option - 6 messages, 1 author
http://groups.google.com/group/linux.kernel/t/a2b106be220a1f65?hl=en
* mm/zswap: Check all pool pages instead of one pool pages - 1 messages, 1
author
http://groups.google.com/group/linux.kernel/t/81cd07f00a212f3a?hl=en
* perf on raspberry-pi without overflow interrupt - 2 messages, 1 author
http://groups.google.com/group/linux.kernel/t/a41a2323b165e1d8?hl=en
* linux-next: manual merge of the tip tree with the net-next tree - 1 messages,
1 author
http://groups.google.com/group/linux.kernel/t/ec246d2e3d0c7bcd?hl=en
* linux-next: manual merge of the akpm-current tree with the tip tree - 1
messages, 1 author
http://groups.google.com/group/linux.kernel/t/dbed449ea85f37ac?hl=en
* linux-next: manual merge of the akpm-current tree with the char-misc tree -
1 messages, 1 author
http://groups.google.com/group/linux.kernel/t/1cff4bcb8a419506?hl=en

==============================================================================
TOPIC: clk: Allow drivers to pass in a regmap
http://groups.google.com/group/linux.kernel/t/e089bad72bfa5919?hl=en
==============================================================================

== 1 of 1 ==
Date: Mon, Jan 13 2014 8:00 pm
From: Saravana Kannan


On 01/08/2014 05:51 PM, Mike Turquette wrote:
> Quoting Stephen Boyd (2013-12-23 17:12:26)
>> Add support to the clock core so that drivers can pass in a
>> regmap. If no regmap is specified try to query the device that's
>> registering the clock for its regmap. This should allow drivers
>> to use the core regmap helpers. This is based on a similar design
>> in the regulator framework.
>>
>> Cc: Mark Brown <broonie@kernel.org>
>> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
>> ---
>> drivers/clk/clk.c | 8 ++++++++
>> include/linux/clk-provider.h | 7 +++++++
>> 2 files changed, 15 insertions(+)
>>
>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>> index 9ad7b71..5e71f5c 100644
>> --- a/drivers/clk/clk.c
>> +++ b/drivers/clk/clk.c
>> @@ -20,6 +20,7 @@
>> #include <linux/device.h>
>> #include <linux/init.h>
>> #include <linux/sched.h>
>> +#include <linux/regmap.h>
>>
>> static DEFINE_SPINLOCK(enable_lock);
>> static DEFINE_MUTEX(prepare_lock);
>> @@ -1834,6 +1835,13 @@ static int _clk_register(struct device *dev, struct clk_hw *hw, struct clk *clk)
>> clk->num_parents = hw->init->num_parents;
>> hw->clk = clk;
>>
>> + if (hw->init->regmap)
>> + hw->regmap = hw->init->regmap;
>
> Hi Stephen,
>
> The whole series looks good to me except for the placement of the regmap
> details inside struct clk_hw. That structure exists only to hide struct
> clk from the hardware-specific clock structure and I'd not like to set
> the precedent of shoving per-clock data into it.
>
> As an alternative, how about finding a way to put these per-clock regmap
> details into the hardware-specific clock structure? I understand that
> you want to make these ops available to others, which is why they are in
> the public struct clk_hw. I'm just wondering if that is the right way to
> do it...
>
> Patch #3 illustrates the sort of struct-member-creep that worries me.
> What is to stop someone from putting "unsigned int divider_reg" or
> "unsigned int mux_reg", and then the thing just keeps growing.

I agree with Mike here. This definitely encourages struct field creep if
more people want to use it.

I talked to Stephen is person and my recommendation is to not have any
new fields other than struct regmap in clk_hw and remove the above 2
lines of code.

>> + else if (dev && dev_get_regmap(dev, NULL))
>> + hw->regmap = dev_get_regmap(dev, NULL);

Move "struct regmap *regmap" into struct clk_hw (since it's truly
reusable across clock types and is technically purely HW related) and
update it from the device's regmap like above.

We can then provide __clk_regmap_enable(regmap, offset, enable_mask)
helper functions. Then clock specific functions can use the helper. We
can even a simple macro to generate these wrappers.

#define DEFINE_REGMAP_EN_DIS(clktype) \

int clk_type##_enable(clktype *c, ....) { }
int clk_type##_disable(clktype *c, ....) { }


That to me seems like a reasonable compromise.

Thanks,
Saravana
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==============================================================================
TOPIC: Tegra baseline test results for v3.13-rc8
http://groups.google.com/group/linux.kernel/t/787a0b232eb0cfdb?hl=en
==============================================================================

== 1 of 1 ==
Date: Mon, Jan 13 2014 8:10 pm
From: Paul Walmsley


Here are some basic Tegra test results for Linux v3.13-rc8.
Logs and other details at:

http://nvt.pwsan.com/pub/linux/testlogs/test_v3.13-rc8/20140112023108/


Test summary
------------

Build: zImage:
Pass: ( 2/ 2): multi_v7_defconfig, tegra_defconfig

Boot to userspace: multi_v7_defconfig:
Pass: ( 2/ 2): tegra114-dalmore-headless, tegra30-beaver

Boot to userspace: tegra_defconfig:
Pass: ( 2/ 2): tegra114-dalmore-headless, tegra30-beaver


vmlinux object size
(delta in bytes from test_v3.13-rc7 (d6e0a2dd12f4067a5bcefb8bbd8ddbeff800afbc)):
text data bss total kernel
+56 0 0 +56 multi_v7_defconfig
+1373 -24 0 +1349 tegra_defconfig


Boot-time memory difference
(delta in bytes from test_v3.13-rc7 (d6e0a2dd12f4067a5bcefb8bbd8ddbeff800afbc))
avail rsrvd high freed board kconfig dtb
. . . . tegra114-dalmore-hea multi_v7_defconfig tegra114-dalmore
. . . . tegra114-dalmore-hea tegra_defconfig tegra114-dalmore
. . . . tegra30-beaver multi_v7_defconfig tegra30-beaver
. . . . tegra30-beaver tegra_defconfig tegra30-beaver


- Paul
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==============================================================================
TOPIC: next bio iters break discard?
http://groups.google.com/group/linux.kernel/t/df8973f865430413?hl=en
==============================================================================

== 1 of 2 ==
Date: Mon, Jan 13 2014 8:10 pm
From: "Martin K. Petersen"


>>>>> "Kent" == Kent Overstreet <kmo@daterainc.com> writes:

Kent,

Kent> I think for discards we can deal with this easily enough -
Kent> __blk_recalc_rq_segments() will have to special case them - but
Kent> there's a similar (but worse) issue with WRITE_SAME, and looking
Kent> at the code it does attempt to merge WRITE_SAME requests too.

DISCARD bios have no payload going down the stack. They get a payload
attached in the sd driver and will therefore have a single bvec at
completion time.

WRITE_SAME bios have a single bvec payload throughout their lifetime.

For both these types of requests we never attempt to merge the actual
payloads. But the block range worked on may shrink or grow as the bio is
split or merged going down the stack.

IOW, DISCARD, WRITE SAME and the impending COPY requests do not have a
1:1 mapping between the block range worked on and the size of any bvecs
attached. Your recent changes must have changed the way we handled that
in the past.

I'll take a look tomorrow...

--
Martin K. Petersen Oracle Linux Engineering
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== 2 of 2 ==
Date: Mon, Jan 13 2014 8:50 pm
From: Kent Overstreet


On Mon, Jan 13, 2014 at 11:06:33PM -0500, Martin K. Petersen wrote:
> >>>>> "Kent" == Kent Overstreet <kmo@daterainc.com> writes:
>
> Kent,
>
> Kent> I think for discards we can deal with this easily enough -
> Kent> __blk_recalc_rq_segments() will have to special case them - but
> Kent> there's a similar (but worse) issue with WRITE_SAME, and looking
> Kent> at the code it does attempt to merge WRITE_SAME requests too.
>
> DISCARD bios have no payload going down the stack. They get a payload
> attached in the sd driver and will therefore have a single bvec at
> completion time.
>
> WRITE_SAME bios have a single bvec payload throughout their lifetime.
>
> For both these types of requests we never attempt to merge the actual
> payloads. But the block range worked on may shrink or grow as the bio is
> split or merged going down the stack.
>
> IOW, DISCARD, WRITE SAME and the impending COPY requests do not have a
> 1:1 mapping between the block range worked on and the size of any bvecs
> attached. Your recent changes must have changed the way we handled that
> in the past.

Yeah - but with WRITE_SAME bios, wouldn't we at least have to check that they're
writing the same data to merge them?
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==============================================================================
TOPIC: Drivers: hv: Implement the file copy service
http://groups.google.com/group/linux.kernel/t/e6745e5c9e6c7e65?hl=en
==============================================================================

== 1 of 1 ==
Date: Mon, Jan 13 2014 8:10 pm
From: "K. Y. Srinivasan"


Implement the file copy service for Linux guests on Hyper-V. This permits the
host to copy a file (over VMBUS) into the guest. This facility is part of
"guest integration services" supported on the Windows platform.
Here is a link that provides additional details on this functionality:

http://technet.microsoft.com/en-us/library/dn464282.aspx

In this version of the patch I have addressed comments from
Olaf Hering <olaf@aepfle.de> and Dan Carpenter <dan.carpenter@oracle.com>

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
drivers/hv/Makefile | 2 +-
drivers/hv/hv_fcopy.c | 422 ++++++++++++++++++++++++++++++++++++++++++++
drivers/hv/hv_util.c | 10 +
include/linux/hyperv.h | 60 +++++++
tools/hv/hv_fcopy_daemon.c | 173 ++++++++++++++++++
5 files changed, 666 insertions(+), 1 deletions(-)
create mode 100644 drivers/hv/hv_fcopy.c
create mode 100644 tools/hv/hv_fcopy_daemon.c

diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile
index 0a74b56..5e4dfa4 100644
--- a/drivers/hv/Makefile
+++ b/drivers/hv/Makefile
@@ -5,4 +5,4 @@ obj-$(CONFIG_HYPERV_BALLOON) += hv_balloon.o
hv_vmbus-y := vmbus_drv.o \
hv.o connection.o channel.o \
channel_mgmt.o ring_buffer.o
-hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o
+hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o hv_fcopy.o
diff --git a/drivers/hv/hv_fcopy.c b/drivers/hv/hv_fcopy.c
new file mode 100644
index 0000000..06484b4
--- /dev/null
+++ b/drivers/hv/hv_fcopy.c
@@ -0,0 +1,422 @@
+/*
+ * An implementation of file copy service.
+ *
+ * Copyright (C) 2014, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <ksrinivasan@novell.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/semaphore.h>
+#include <linux/fs.h>
+#include <linux/nls.h>
+#include <linux/workqueue.h>
+#include <linux/cdev.h>
+#include <linux/hyperv.h>
+#include <linux/sched.h>
+#include <linux/uaccess.h>
+
+#define WIN8_SRV_MAJOR 1
+#define WIN8_SRV_MINOR 1
+#define WIN8_SRV_VERSION (WIN8_SRV_MAJOR << 16 | WIN8_SRV_MINOR)
+
+/*
+ * Global state maintained for transaction that is being processed.
+ * For a class of integration services, including the "file copy service",
+ * the specified protocol is a "request/response" protocol which means that
+ * there can only be single outstanding transaction from the host at any
+ * given point in time. We use this to simplify memory management in this
+ * driver - we cache and process only one message at a time.
+ *
+ * While the request/response protocol is guaranteed by the host, we further
+ * ensure this by serializing packet processing in this driver - we do not
+ * read additional packets from the VMBUs until the current packet is fully
+ * handled.
+ *
+ * The transaction "active" state is set when we receive a request from the
+ * host and we cleanup this state when the transaction is completed - when we
+ * respond to the host with our response. When the transaction active state is
+ * set, we defer handling incoming packets.
+ */
+
+static struct {
+ bool active; /* transaction status - active or not */
+ int recv_len; /* number of bytes received. */
+ struct hv_fcopy_hdr *fcopy_msg; /* current message */
+ struct hv_start_fcopy message; /* sent to daemon */
+ struct vmbus_channel *recv_channel; /* chn we got the request */
+ u64 recv_req_id; /* request ID. */
+ void *fcopy_context; /* for the channel callback */
+ struct semaphore read_sema;
+} fcopy_transaction;
+
+static dev_t fcopy_dev;
+static bool daemon_died;
+static bool opened; /* currently device opened */
+static struct task_struct *dtp; /* daemon task ptr */
+
+/*
+ * Before we can accept copy messages from the host, we need
+ * to handshake with the user level daemon. This state tracks
+ * if we are in the handshake phase.
+ */
+static bool in_hand_shake = true;
+static void fcopy_send_data(void);
+static void fcopy_respond_to_host(int error);
+static void fcopy_work_func(struct work_struct *dummy);
+static DECLARE_DELAYED_WORK(fcopy_work, fcopy_work_func);
+static u8 *recv_buffer;
+
+static void fcopy_work_func(struct work_struct *dummy)
+{
+ /*
+ * If the timer fires, the user-mode component has not responded;
+ * process the pending transaction.
+ */
+ fcopy_respond_to_host(HV_E_FAIL);
+}
+
+static void fcopy_handle_handshake(void)
+{
+ pr_info("FCP: user-mode registering done.\n");
+ fcopy_transaction.active = false;
+ if (fcopy_transaction.fcopy_context)
+ hv_fcopy_onchannelcallback(fcopy_transaction.fcopy_context);
+ in_hand_shake = false;
+ return;
+}
+
+static void fcopy_send_data(void)
+{
+ struct hv_start_fcopy *smsg_out = &fcopy_transaction.message;
+ int operation = fcopy_transaction.fcopy_msg->operation;
+ struct hv_start_fcopy *smsg_in;
+
+ /*
+ * The strings sent from the host are encoded in
+ * in utf16; convert it to utf8 strings.
+ * The host assures us that the utf16 strings will not exceed
+ * the max lengths specified. We will however, reserve room
+ * for the string terminating character - in the utf16s_utf8s()
+ * function we limit the size of the buffer where the converted
+ * string is placed to W_MAX_PATH -1 to gaurantee
+ * that the strings can be properly terminated!
+ */
+
+ switch (operation) {
+ case START_FILE_COPY:
+ memset(smsg_out, 0, sizeof(struct hv_start_fcopy));
+ smsg_out->hdr.operation = operation;
+ smsg_in = (struct hv_start_fcopy *)fcopy_transaction.fcopy_msg;
+
+ utf16s_to_utf8s((wchar_t *)smsg_in->file_name, W_MAX_PATH,
+ UTF16_LITTLE_ENDIAN,
+ (__u8 *)smsg_out->file_name, W_MAX_PATH - 1);
+
+ utf16s_to_utf8s((wchar_t *)smsg_in->path_name, W_MAX_PATH,
+ UTF16_LITTLE_ENDIAN,
+ (__u8 *)smsg_out->path_name, W_MAX_PATH - 1);
+
+ smsg_out->copy_flags = smsg_in->copy_flags;
+ smsg_out->file_size = smsg_in->file_size;
+ break;
+
+ default:
+ break;
+ }
+ up(&fcopy_transaction.read_sema);
+ return;
+}
+
+/*
+ * Send a response back to the host.
+ */
+
+static void
+fcopy_respond_to_host(int error)
+{
+ struct icmsg_hdr *icmsghdrp;
+ u32 buf_len;
+ struct vmbus_channel *channel;
+ u64 req_id;
+
+ /*
+ * Copy the global state for completing the transaction. Note that
+ * only one transaction can be active at a time.
+ */
+
+ buf_len = fcopy_transaction.recv_len;
+ channel = fcopy_transaction.recv_channel;
+ req_id = fcopy_transaction.recv_req_id;
+
+ fcopy_transaction.active = false;
+
+ icmsghdrp = (struct icmsg_hdr *)
+ &recv_buffer[sizeof(struct vmbuspipe_hdr)];
+
+ if (channel->onchannel_callback == NULL)
+ /*
+ * We have raced with util driver being unloaded;
+ * silently return.
+ */
+ return;
+
+ icmsghdrp->status = error;
+ icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
+ vmbus_sendpacket(channel, recv_buffer, buf_len, req_id,
+ VM_PKT_DATA_INBAND, 0);
+}
+
+void hv_fcopy_onchannelcallback(void *context)
+{
+ struct vmbus_channel *channel = context;
+ u32 recvlen;
+ u64 requestid;
+ struct hv_fcopy_hdr *fcopy_msg;
+ struct icmsg_hdr *icmsghdrp;
+ struct icmsg_negotiate *negop = NULL;
+ int util_fw_version;
+ int fcopy_srv_version;
+
+ if (fcopy_transaction.active) {
+ /*
+ * We will defer processing this callback once
+ * the current transaction is complete.
+ */
+ fcopy_transaction.fcopy_context = context;
+ return;
+ }
+
+ vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
+ &requestid);
+ if (recvlen <= 0)
+ return;
+
+ icmsghdrp = (struct icmsg_hdr *)&recv_buffer[
+ sizeof(struct vmbuspipe_hdr)];
+ if (icmsghdrp->icmsgtype == ICMSGTYPE_NEGOTIATE) {
+ util_fw_version = UTIL_FW_VERSION;
+ fcopy_srv_version = WIN8_SRV_VERSION;
+ vmbus_prep_negotiate_resp(icmsghdrp, negop, recv_buffer,
+ util_fw_version, fcopy_srv_version);
+ } else {
+ fcopy_msg = (struct hv_fcopy_hdr *)&recv_buffer[
+ sizeof(struct vmbuspipe_hdr) +
+ sizeof(struct icmsg_hdr)];
+
+ /*
+ * Stash away this global state for completing the
+ * transaction; note transactions are serialized.
+ */
+
+ fcopy_transaction.active = true;
+ fcopy_transaction.recv_len = recvlen;
+ fcopy_transaction.recv_channel = channel;
+ fcopy_transaction.recv_req_id = requestid;
+ fcopy_transaction.fcopy_msg = fcopy_msg;
+
+ /*
+ * Send the information to the user-level daemon.
+ */
+ fcopy_send_data();
+ schedule_delayed_work(&fcopy_work, 5*HZ);
+ return;
+ }
+ icmsghdrp->icflags = ICMSGHDRFLAG_TRANSACTION | ICMSGHDRFLAG_RESPONSE;
+ vmbus_sendpacket(channel, recv_buffer, recvlen, requestid,
+ VM_PKT_DATA_INBAND, 0);
+}
+
+/*
+ * Create a char device that can support read/write for passing
+ * the payload.
+ */
+struct cdev fcopy_cdev;
+struct class *cl;
+struct device *sysfs_dev;
+
+static ssize_t fcopy_read(struct file *file, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int ret;
+ void *src;
+ size_t copy_size;
+ int operation;
+
+ /*
+ * Wait until there is something to be read.
+ */
+ ret = down_interruptible(&fcopy_transaction.read_sema);
+ if (ret)
+ return -EINTR;
+
+ operation = fcopy_transaction.fcopy_msg->operation;
+
+ if (operation == START_FILE_COPY) {
+ src = &fcopy_transaction.message;
+ copy_size = sizeof(struct hv_start_fcopy);
+ if (count < copy_size)
+ return 0;
+ } else {
+ src = fcopy_transaction.fcopy_msg;
+ copy_size = sizeof(struct hv_do_fcopy);
+ if (count < copy_size)
+ return 0;
+ }
+ if (copy_to_user(buf, src, copy_size))
+ return -EFAULT;
+
+ return copy_size;
+}
+
+static ssize_t fcopy_write(struct file *file, const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ int error = 0;
+
+ if (count != sizeof(int))
+ return 0;
+
+ if (copy_from_user(&error, buf, sizeof(int)))
+ return -EFAULT;
+
+ if (in_hand_shake) {
+ fcopy_handle_handshake();
+ return 0;
+ }
+
+ /*
+ * Complete the transaction by forwarding the result
+ * to the host. But first, cancel the timeout.
+ */
+ if (cancel_delayed_work_sync(&fcopy_work))
+ fcopy_respond_to_host(error);
+
+ return sizeof(int);
+}
+
+int fcopy_open(struct inode *inode, struct file *f)
+{
+ if (opened)
+ return -EBUSY;
+
+ /*
+ * The daemon is alive; setup the state.
+ */
+ daemon_died = false;
+ opened = true;
+ dtp = current;
+ return 0;
+}
+
+int fcopy_release(struct inode *inode, struct file *f)
+{
+ /*
+ * The daemon has exited; reset the state.
+ */
+ daemon_died = true;
+ in_hand_shake = true;
+ dtp = NULL;
+ opened = false;
+ return 0;
+}
+
+
+static const struct file_operations fcopy_fops = {
+ .read = fcopy_read,
+ .write = fcopy_write,
+ .release = fcopy_release,
+ .open = fcopy_open,
+};
+
+static int fcopy_dev_init(void)
+{
+ int result;
+
+ result = alloc_chrdev_region(&fcopy_dev, 1, 1, "hv_fcopy");
+ if (result < 0) {
+ pr_err("Cannot get major number\n");
+ return result;
+ }
+
+ cl = class_create(THIS_MODULE, "chardev");
+ if (IS_ERR(cl)) {
+ pr_err("Error creating fcopy class.\n");
+ result = PTR_ERR(cl);
+ goto err_unregister;
+ }
+
+ sysfs_dev = device_create(cl, NULL, fcopy_dev, "%s", "hv_fcopy");
+ if (IS_ERR(sysfs_dev)) {
+ pr_err("Device creation failed\n");
+ result = PTR_ERR(cl);
+ goto err_destroy_class;
+ }
+
+ cdev_init(&fcopy_cdev, &fcopy_fops);
+ fcopy_cdev.owner = THIS_MODULE;
+ fcopy_cdev.ops = &fcopy_fops;
+
+ result = cdev_add(&fcopy_cdev, fcopy_dev, 1);
+ if (result) {
+ pr_err("Cannot cdev_add\n");
+ goto err_destroy_device;
+ }
+ return result;
+
+err_destroy_device:
+ device_destroy(cl, fcopy_dev);
+err_destroy_class:
+ class_destroy(cl);
+err_unregister:
+ unregister_chrdev_region(fcopy_dev, 1);
+ return result;
+}
+
+static void fcopy_dev_deinit(void)
+{
+ /*
+ * first kill the daemon.
+ */
+ if (dtp != NULL)
+ send_sig(SIGKILL, dtp, 0);
+ opened = false;
+ device_destroy(cl, fcopy_dev);
+ class_destroy(cl);
+ cdev_del(&fcopy_cdev);
+ unregister_chrdev_region(fcopy_dev, 1);
+}
+
+int hv_fcopy_init(struct hv_util_service *srv)
+{
+ recv_buffer = srv->recv_buffer;
+
+ /*
+ * When this driver loads, the user level daemon that
+ * processes the host requests may not yet be running.
+ * Defer processing channel callbacks until the daemon
+ * has registered.
+ */
+ fcopy_transaction.active = true;
+ sema_init(&fcopy_transaction.read_sema, 0);
+
+ return fcopy_dev_init();
+}
+
+void hv_fcopy_deinit(void)
+{
+ cancel_delayed_work_sync(&fcopy_work);
+ fcopy_dev_deinit();
+}
diff --git a/drivers/hv/hv_util.c b/drivers/hv/hv_util.c
index 62dfd246..efc5e83 100644
--- a/drivers/hv/hv_util.c
+++ b/drivers/hv/hv_util.c
@@ -82,6 +82,12 @@ static struct hv_util_service util_vss = {
.util_deinit = hv_vss_deinit,
};

+static struct hv_util_service util_fcopy = {
+ .util_cb = hv_fcopy_onchannelcallback,
+ .util_init = hv_fcopy_init,
+ .util_deinit = hv_fcopy_deinit,
+};
+
static void perform_shutdown(struct work_struct *dummy)
{
orderly_poweroff(true);
@@ -401,6 +407,10 @@ static const struct hv_vmbus_device_id id_table[] = {
{ HV_VSS_GUID,
.driver_data = (unsigned long)&util_vss
},
+ /* File copy GUID */
+ { HV_FCOPY_GUID,
+ .driver_data = (unsigned long)&util_fcopy
+ },
{ },
};

diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 15da677..e573ae9 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -26,6 +26,8 @@
#define _HYPERV_H

#include <linux/types.h>
+#include <linux/uuid.h>
+#include <linux/limits.h>

/*
* Framework version for util services.
@@ -96,6 +98,49 @@ struct hv_vss_msg {
} __attribute__((packed));

/*
+ * Implementation of a host to guest copy facility.
+ */
+
+#define W_MAX_PATH 260
+
+enum hv_fcopy_op {
+ START_FILE_COPY = 0,
+ WRITE_TO_FILE,
+ COMPLETE_FCOPY,
+ CANCEL_FCOPY,
+};
+
+struct hv_fcopy_hdr {
+ enum hv_fcopy_op operation;
+ uuid_le service_id0; /* currently unused */
+ uuid_le service_id1; /* currently unused */
+} __attribute__((packed));
+
+#define OVER_WRITE 0x1
+#define CREATE_PATH 0x2
+
+struct hv_start_fcopy {
+ struct hv_fcopy_hdr hdr;
+ __u16 file_name[W_MAX_PATH];
+ __u16 path_name[W_MAX_PATH];
+ __u32 copy_flags;
+ __u64 file_size;
+} __attribute__((packed));
+
+/*
+ * The file is chunked into fragments.
+ */
+#define DATA_FRAGMENT (6 * 1024)
+
+struct hv_do_fcopy {
+ struct hv_fcopy_hdr hdr;
+ __u64 offset;
+ __u32 size;
+ __u8 data[DATA_FRAGMENT];
+};
+
+
+/*
* An implementation of HyperV key value pair (KVP) functionality for Linux.
*
*
@@ -1352,6 +1397,17 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver);
}

/*
+ * Guest File Copy Service
+ * {34D14BE3-DEE4-41c8-9AE7-6B174977C192}
+ */
+
+#define HV_FCOPY_GUID \
+ .guid = { \
+ 0xE3, 0x4B, 0xD1, 0x34, 0xE4, 0xDE, 0xC8, 0x41, \
+ 0x9A, 0xE7, 0x6B, 0x17, 0x49, 0x77, 0xC1, 0x92 \
+ }
+
+/*
* Common header for Hyper-V ICs
*/

@@ -1459,6 +1515,10 @@ int hv_vss_init(struct hv_util_service *);
void hv_vss_deinit(void);
void hv_vss_onchannelcallback(void *);

+int hv_fcopy_init(struct hv_util_service *);
+void hv_fcopy_deinit(void);
+void hv_fcopy_onchannelcallback(void *);
+
/*
* Negotiated version with the Host.
*/
diff --git a/tools/hv/hv_fcopy_daemon.c b/tools/hv/hv_fcopy_daemon.c
new file mode 100644
index 0000000..4b73ce6
--- /dev/null
+++ b/tools/hv/hv_fcopy_daemon.c
@@ -0,0 +1,173 @@
+/*
+ * An implementation of host to guest copy functionality for Linux.
+ *
+ * Copyright (C) 2014, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <kys@microsoft.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ */
+
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/poll.h>
+#include <linux/types.h>
+#include <linux/kdev_t.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <ctype.h>
+#include <errno.h>
+#include <linux/hyperv.h>
+#include <syslog.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+
+static int target_fd;
+char target_fname[W_MAX_PATH];
+
+static int hv_start_fcopy(struct hv_start_fcopy *smsg)
+{
+ int error = HV_E_FAIL;
+
+ sprintf(target_fname, "%s%s%s", smsg->path_name, "/",
+ smsg->file_name);
+
+ syslog(LOG_INFO, "Target file name: %s\n", target_fname);
+ /*
+ * Check to see if the path is already in place; if not,
+ * create if required.
+ */
+ if (access((char *)smsg->path_name, F_OK)) {
+ if (smsg->copy_flags & CREATE_PATH) {
+ if (mkdir((char *)smsg->path_name, 0755)) {
+ syslog(LOG_ERR,
+ "Failed to create '%s'; error: %d %s\n",
+ smsg->path_name,
+ errno, strerror(errno));
+ goto done;
+ }
+ } else {
+ syslog(LOG_ERR, "Invalid path: %s\n", smsg->path_name);
+ goto done;
+ }
+ }
+
+ if (!access(target_fname, F_OK)) {
+ syslog(LOG_INFO, "File: %s exists\n", target_fname);
+ if (!smsg->copy_flags & OVER_WRITE)
+ goto done;
+ }
+
+ target_fd = open(target_fname, O_RDWR | O_CREAT | O_CLOEXEC, 0744);
+ if (target_fd == -1) {
+ syslog(LOG_INFO, "Open Failed: %s\n", strerror(errno));
+ goto done;
+ }
+
+ error = 0;
+done:
+ return error;
+}
+
+static int hv_copy_data(struct hv_do_fcopy *cpmsg)
+{
+ ssize_t bytes_written;
+
+ bytes_written = pwrite(target_fd, cpmsg->data, cpmsg->size,
+ cpmsg->offset);
+
+ if (bytes_written != cpmsg->size)
+ return HV_E_FAIL;
+
+ return 0;
+}
+
+static int hv_copy_finished(void)
+{
+ close(target_fd);
+ return 0;
+}
+static int hv_copy_cancel(void)
+{
+ close(target_fd);
+ unlink(target_fname);
+ return 0;
+
+}
+
+int main(void)
+{
+ int fd, fcopy_fd, len;
+ int error = 0;
+ int version = 0;
+ char *buffer[4096 * 2];
+ struct hv_fcopy_hdr *in_msg;
+
+ daemon(1, 0);
+ openlog("HV_FCOPY", 0, LOG_USER);
+ syslog(LOG_INFO, "HV_FCOPY starting; pid is:%d", getpid());
+
+ fcopy_fd = open("/dev/hv_fcopy", O_RDWR);
+
+ if (fcopy_fd < 0) {
+ syslog(LOG_ERR, "open /dev/hv_fcopy failed; error: %d %s",
+ errno, strerror(errno));
+ exit(EXIT_FAILURE);
+ }
+
+ /*
+ * Register with the kernel.
+ */
+ write(fcopy_fd, &version, sizeof(int));
+
+ while (1) {
+ /*
+ * In this loop we process fcopy messages after the
+ * handshake is complete.
+ */
+
+ len = pread(fcopy_fd, buffer, (4096 * 2), 0);
+ if (len <= 0) {
+ if (!error) {
+ syslog(LOG_ERR, "Read error: %s\n", strerror(errno));
+ error = HV_E_FAIL;
+ }
+ continue;
+ }
+ in_msg = (struct hv_fcopy_hdr *)buffer;
+
+ switch (in_msg->operation) {
+ case START_FILE_COPY:
+ error = hv_start_fcopy((struct hv_start_fcopy *)in_msg);
+ break;
+ case WRITE_TO_FILE:
+ error = hv_copy_data((struct hv_do_fcopy *)in_msg);
+ break;
+ case COMPLETE_FCOPY:
+ error = hv_copy_finished();
+ break;
+ case CANCEL_FCOPY:
+ error = hv_copy_cancel();
+ break;
+
+ default:
+ syslog(LOG_ERR, "Unknown operation: %d\n",
+ in_msg->operation);
+
+ }
+
+ pwrite(fcopy_fd, &error, sizeof(int), 0);
+ }
+}
--
1.7.4.1

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==============================================================================
TOPIC: timers: Reduce __run_timers() latency for empty list
http://groups.google.com/group/linux.kernel/t/9be12def62cea4b8?hl=en
==============================================================================

== 1 of 4 ==
Date: Mon, Jan 13 2014 8:20 pm
From: "Paul E. McKenney"


From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

The __run_timers() function currently steps through the list one jiffy at
a time in order to update the timer wheel. However, if the timer wheel
is empty, no adjustment is needed other than updating ->timer_jiffies.
In this case, which is likely to be common for NO_HZ_FULL kernels, the
kernel currently incurs a large latency for no good reason. This commit
therefore short-circuits this case.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
kernel/timer.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/kernel/timer.c b/kernel/timer.c
index 6582b82fa966..21849275828f 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -337,6 +337,17 @@ void set_timer_slack(struct timer_list *timer, int slack_hz)
}
EXPORT_SYMBOL_GPL(set_timer_slack);

+static bool catchup_timer_jiffies(struct tvec_base *base)
+{
+#ifdef CONFIG_NO_HZ_FULL
+ if (!base->active_timers) {
+ base->timer_jiffies = jiffies;
+ return 1;
+ }
+