There are some dependencies between devices (in particular, between
EHCI USB controllers and their OHCI/UHCI siblings) which are not
reflected by the structure of the device tree. With synchronous
suspend and resume these dependencies are taken into accout
automatically, because the devices in question are always registered
in the right order, but to meet these constraints with asynchronous
suspend and resume the drivers of these devices will need to use
dpm_wait() in their suspend/resume routines, so introduce a helper
function allowing them to do that.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
It has been shown by testing that total device resume time can be
reduced significantly (by as much as 50% or more) if the async
threads executing some devices' resume routines are all started
before the main resume thread starts to handle the "synchronous"
devices.
This is a consequence of the fact that the slowest devices tend to be
located at the end of dpm_list, so their resume routines are started
very late. Consequently, they have to wait for all the preceding
"synchronous" devices before their resume routines can be started
by the main resume thread, even if they are "asynchronous". By
starting their async threads upfront we effectively move those
devices towards the beginning of dpm_list, without breaking their
ordering with respect to their parents and children. As a result,
their resume routines are started much earlier and we are able to
save much more device resume time this way.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add configuration switch CONFIG_PM_ADVANCED_DEBUG for compiling in
extra PM debugging/testing code allowing one to access some
PM-related attributes of devices from the user space via sysfs.
If CONFIG_PM_ADVANCED_DEBUG is set, add sysfs attribute power/async
for every device allowing the user space to access the device's
power.async_suspend flag and modify it, if desired.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add sysfs attribute /sys/power/pm_async allowing the user space to
disable/enable asynchronous suspend/resume of devices.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Theoretically, the total time of system sleep transitions (suspend
to RAM, hibernation) can be reduced by running suspend and resume
callbacks of device drivers in parallel with each other. However,
there are dependencies between devices such that we're not allowed
to suspend the parent of a device before suspending the device
itself. Analogously, we're not allowed to resume a device before
resuming its parent.
The most straightforward way to take these dependencies into accout
is to start the async threads used for suspending and resuming
devices at the core level, so that async_schedule() is called for
each suspend and resume callback supposed to be executed
asynchronously.
For this purpose, introduce a new device flag, power.async_suspend,
used to mark the devices whose suspend and resume callbacks are to be
executed asynchronously (ie. in parallel with the main suspend/resume
thread and possibly in parallel with each other) and helper function
device_enable_async_suspend() allowing one to set power.async_suspend
for given device (power.async_suspend is unset by default for all
devices). For each device with the power.async_suspend flag set the
PM core will use async_schedule() to execute its suspend and resume
callbacks.
The async threads started for different devices as a result of
calling async_schedule() are synchronized with each other and with
the main suspend/resume thread with the help of completions, in the
following way:
(1) There is a completion, power.completion, for each device object.
(2) Each device's completion is reset before calling async_schedule()
for the device or, in the case of devices with the
power.async_suspend flags unset, before executing the device's
suspend and resume callbacks.
(3) During suspend, right before running the bus type, device type
and device class suspend callbacks for the device, the PM core
waits for the completions of all the device's children to be
completed.
(4) During resume, right before running the bus type, device type and
device class resume callbacks for the device, the PM core waits
for the completion of the device's parent to be completed.
(5) The PM core completes power.completion for each device right
after the bus type, device type and device class suspend (or
resume) callbacks executed for the device have returned.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Add new device sysfs attribute, power/control, allowing the user
space to block the run-time power management of the devices. If this
attribute is set to "on", the driver of the device won't be able to power
manage it at run time (without breaking the rules) and the device will
always be in the full power state (except when the entire system goes
into a sleep state).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
* 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (48 commits)
x86/PCI: Prevent mmconfig memory corruption
ACPI: Use GPE reference counting to support shared GPEs
x86/PCI: use host bridge _CRS info by default on 2008 and newer machines
PCI: augment bus resource table with a list
PCI: add pci_bus_for_each_resource(), remove direct bus->resource[] refs
PCI: read bridge windows before filling in subtractive decode resources
PCI: split up pci_read_bridge_bases()
PCIe PME: use pci_pcie_cap()
PCI PM: Run-time callbacks for PCI bus type
PCIe PME: use pci_is_pcie()
PCI / ACPI / PM: Platform support for PCI PME wake-up
ACPI / ACPICA: Multiple system notify handlers per device
ACPI / PM: Add more run-time wake-up fields
ACPI: Use GPE reference counting to support shared GPEs
PCI PM: Make it possible to force using INTx for PCIe PME signaling
PCI PM: PCIe PME root port service driver
PCI PM: Add function for checking PME status of devices
PCI: mark is_pcie obsolete
PCI: set PCI_PREF_RANGE_TYPE_64 in pci_bridge_check_ranges
PCI: pciehp: second try to get big range for pcie devices
...
The five-second delay can be rather annoying, and makes the system
appear much less responsive when you connect a USB drive.
It's also not entirely clear that it is needed - the settling delay has
at least historically been an issue on some Apple iPods, for example,
and some devices have been reported to need even more than the old 5s
delay.
But before we penalize them all, let's see how bad it really is. Some
of the reasons for long delays seem to be actual historical kernel bugs
that should probably never have been papered over with a delay in the
first place (there's a Ubuntu bug report for 2.6.20 about a NULL pointer
dereference unless 'delay_use' is 8 or more, for example).
It also looks like some distros have already shipped with delay_use=0,
so the five second default may well be totally historical.
In other words: "Let's see if anybody screams".
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6: (41 commits)
of: remove undefined request_OF_resource & release_OF_resource
of/sparc: Remove sparc-local declaration of allnodes and devtree_lock
of: move definition of of_chosen into common code.
of: remove unused extern reference to devtree_lock
of: put default string compare and #a/s-cell values into common header
of/flattree: Don't assume HAVE_LMB
of: protect linux/of.h with CONFIG_OF
proc_devtree: fix THIS_MODULE without module.h
of: Remove old and misplaced function declarations
of/flattree: Make the kernel accept ePAPR style phandle information
of/flattree: endian-convert members of boot_param_header
of: assume big-endian properties, adding conversions where necessary
of: use __be32 for cell value accessors
of/flattree: use OF_ROOT_NODE_{SIZE,ADDR}_CELLS DEFAULT for fdt parsing
of/flattree: use callback to setup initrd from /chosen
proc_devtree: include linux/of.h
of: make set_node_proc_entry private to proc_devtree.c
of: include linux/proc_fs.h
of/flattree: merge early_init_dt_scan_memory() common code
of: add 'of_' prefix to machine_is_compatible()
...
* 'next-spi' of git://git.secretlab.ca/git/linux-2.6: (31 commits)
spi: Correct SPI clock frequency setting in spi_mpc8xxx
spi/spi_s3c64xx.c: Fix continuation line formats
spi/dw_spi: Fix dw_spi_mmio to depend on HAVE_CLK
spi/dw_spi: Allow dw_spi.c to be a module
spi/dw_spi: mmio code style fixups
Memory-mapped dw_spi driver
spi/dw_spi: fix missing export of dw_spi_remove_host
spi/dw_spi: conditional transfer mode changes
spi/dw_spi: remove conditional from 'poll_transfer'.
spi/dw_spi: fixed a spelling typo in a warning message.
spi/dw_spi: add return value to empty mrst_spi_debugfs_init()
spi/dw_spi: enable platform specific chipselect.
spi/dw_spi: add a FIFO depth detection
spi/dw_spi: fix __init/__devinit section mismatch
spi: xilinx_spi: Fix up I/O routine wrapping bogosity.
spi/spi_imx: add device information by switching pr_debug() to dev_dbg()
spi: update MSIOF includes
spi/dw_spi: refine the IRQ mode working flow
spi/dw_spi: add a missed dw_spi_remove_host() in exit sequence
spi/dw_spi: bug fix in wait_till_not_busy()
...
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid: (41 commits)
HID: usbhid: initialize interface pointers early enough
HID: extend mask for BUTTON usage page
HID: hid-ntrig: Single touch mode tap
HID: hid-ntrig: multitouch cleanup and fix
HID: n-trig: remove unnecessary tool switching
HID: hid-ntrig add multi input quirk and clean up
HID: usbhid: introduce timeout for stuck ctrl/out URBs
HID: magicmouse: coding style and probe failure fixes
HID: remove MODULE_VERSION from new drivers
HID: fix up Kconfig entry for MagicMouse
HID: add a device driver for the Apple Magic Mouse.
HID: Export hid_register_report
HID: Support for MosArt multitouch panel
HID: add pressure support for the Stantum multitouch panel
HID: fixed bug in single-touch emulation on the stantum panel
HID: fix typo in error message
HID: add mapping for "AL Network Chat" usage
HID: use multi input quirk for TouchPack touchscreen
HID: make full-fledged hid-bus drivers properly selectable
HID: make Wacom modesetting failures non-fatal
...
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: (44 commits)
Add MAINTAINERS entry for virtio_console
virtio: console: Fill ports' entire in_vq with buffers
virtio: console: Error out if we can't allocate buffers for control queue
virtio: console: Add ability to remove module
virtio: console: Ensure no memleaks in case of unused buffers
virtio: console: show error message if hvc_alloc fails for console ports
virtio: console: Add debugfs files for each port to expose debug info
virtio: console: Add ability to hot-unplug ports
virtio: console: Handle port hot-plug
virtio: console: Remove cached data on port close
virtio: console: Register with sysfs and create a 'name' attribute for ports
virtio: console: Ensure only one process can have a port open at a time
virtio: console: Add file operations to ports for open/read/write/poll
virtio: console: Associate each port with a char device
virtio: console: Prepare for writing to userspace buffers
virtio: console: Add a new MULTIPORT feature, support for generic ports
virtio: console: Introduce a send_buf function for a common path for sending data to host
virtio: console: Introduce function to hand off data from host to readers
virtio: console: Separate out find_vqs operation into a different function
virtio: console: Separate out console init into a new function
...
Mike Cui reported that his system with an NVIDIA MCP79 (aka MCP7A)
chipset stopped working with 2.6.32. The problem appears to be that
2.6.32 now enables the FPDMA auto-activate optimization in the ahci
driver. The drive works fine with this enabled on an Intel AHCI so
this appears to be a chipset bug. Since MCP79 is a fairly recent
NVIDIA chipset and we don't have any info on whether any other NVIDIA
chipsets have this issue, disable FPDMA AA optimization on all NVIDIA
AHCI controllers for now.
Should address http://bugzilla.kernel.org/show_bug.cgi?id=14922
Signed-off-by: Robert Hancock <hancockrwd@gmail.com>
While-we-investigate-issue-this-patch-looks-good-to-me-by:
Prajakta Gudadhe <pgudadhe@nvidia.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Cc: stable@kernel.org
To fix a bug and address the reviewers' comments regarding the ACPI
GPE refcounting patch, do the following additional changes:
o Remove the second argument of acpi_ev_enable_gpe(),
'write_to_hardware', because it is not necessary any more.
o Add the "bad parameter" test against 'type' in
acpi_enable_gpe() and acpi_disable_gpe().
o Make acpi_enable_gpe() only check 'status' for runtime GPEs if
acpi_ev_enable_gpe() was actually called.
o Make acpi_disable_gpe() return 'status' returned by
acpi_ev_disable_gpe() and fix a bug where ACPI_GPE_TYPE_WAKE
and ACPI_GPE_TYPE_RUNTIME were exchanged by mistake.
o Add comments explaining why acpi_set_gpe() is used by the ACPI EC
driver.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Instead of allocating just one buffer for a port's in_vq, fill
the entire in_vq with buffers so the host need not stall while
an application consumes the data and makes the buffer available
again for the host.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
With MULTIPORT support, the control queue is an integral part of the
functioning of the device. If we can't get any buffers allocated, the
host won't be able to relay important information and the device may not
function as intended.
Ensure 'probe' doesn't succeed until the control queue has at least one
buffer allocated for its ivq.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add the ability to remove the virtio_console module.
This aids debugging.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If unused data exists in in_vq, ensure we flush that first and then
detach unused buffers, which will ensure all buffers from the in_vq are
removed.
Also ensure we free the buffers after detaching them.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove port data; deregister from the hvc core if it's a console port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
If the 'nr_ports' variable in the config space is updated to a higher
value, that means new ports have been hotplugged.
Introduce a new workqueue to handle such updates and create new ports.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove any data that we might have in a port's inbuf when closing a port
or when any data is received when a port is closed.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The host can set a name for ports so that they're easily discoverable
instead of going by the /dev/vportNpn naming. This attribute will be
placed in /sys/class/virtio-ports/vportNpn/name. udev scripts can then
create symlinks to the port using the name.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Add a guest_connected field that ensures only one process
can have a port open at a time.
This also ensures we don't have a race when we later add support for
dropping buffers when closing the char dev and buffer caching is turned
off for the particular port.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Allow guest userspace applications to open, read from, write to, poll
the ports via the char dev interface.
When a port gets opened, a notification is sent to the host via a
control message indicating a connection has been established. Similarly,
on closing of the port, a notification is sent indicating disconnection.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
The char device will be used as an interface by applications on the
guest to communicate with apps on the host.
The devices created are placed in /dev/vportNpn where N is the
virtio-console device number and n is the port number for that device.
One dynamic major device number is allocated for each device and minor
numbers are allocated for the ports contained within that device.
The file operation for the char devs will be added in the following
commits.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When ports get advertised as char devices, the buffers will come from
userspace. Equip the fill_readbuf function with the ability to write
to userspace buffers.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit adds a new feature, MULTIPORT. If the host supports this
feature as well, the config space has the number of ports defined for
that device. New ports are spawned according to this information.
The config space also has the maximum number of ports that can be
spawned for a particular device. This is useful in initializing the
appropriate number of virtqueues in advance, as ports might be
hot-plugged in later.
Using this feature, generic ports can be created which are not tied to
hvc consoles.
We also open up a private channel between the host and the guest via
which some "control" messages are exchanged for the ports, like whether
the port being spawned is a console port, resizing the console window,
etc.
Next commits will add support for hotplugging and presenting char
devices in /dev/ for bi-directional guest-host communication.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Adding support for generic ports that will write to userspace will need
some code changes.
Consolidate the write routine into send_buf() and put_chars() now just
calls into the new function.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
In preparation for serving data to userspace (generic ports) as well as
in-kernel users (hvc consoles), separate out the functionality common to
both in a 'fill_readbuf()' function.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
With support for multiple ports, each port will have its own input and
output vqs. Prepare the probe function for this change.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Console ports could be hot-added. Also, with the new multiport support,
a port is identified as a console port only if the host sends a control
message.
Move the console port init into a separate function so it can be invoked
from other places.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Move out console-specific stuff into a separate struct from 'struct
port' as we need to maintain two lists: one for all the ports (which
includes consoles) and one only for consoles since the hvc callbacks
only give us the vtermno.
This makes console handling cleaner.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
When multiple console support is added, ensure each port's size gets
updated when a new one is opened via hvc.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Rather than assume a single port, add a 'struct ports_device' which
stores data related to all the ports for that device.
Currently, there's only one port and is hooked up with hvc, but that
will change.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Now we can use an allocation function to remove our global console variable.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Keep a list of all ports being used as a console, and provide a lock
and a lookup function. The hvc callbacks only give us a vterm number,
so we need to map this.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Part of removing our "one console" assumptions, use vdev->priv to point
to the port (currently == the global console).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This makes taking locks around the get_buf vq operation easier, as well
as complements the add_inbuf() operation.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
add_inbuf() assumed one port and one inbuf per port. Remove that
assumption.
Also move the function so that put_chars and get_chars are together.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Collect port buffer, used_len, offset fields into a single structure.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We are heading towards a multiple-"port" system, so as part of weaning off
globals we encapsulate the information into 'struct port'.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
We support only one virtio_console device at a time. If multiple are
found, error out if one is already initialized.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is nicer for modern R/O protection. And noone needs it non-const, so
constify the callers as well.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
To: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: linuxppc-dev@ozlabs.org
That way, we can make it const as is good kernel style. We use a separate
indirection for the early console, rather than mugging ops.put_chars.
We rename it hv_ops, too.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Remove old lguest-style comments.
[Amit: - wingify comments acc. to kernel style
- indent comments ]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
vq operations depend on vq->data[i] being NULL to figure out if the vq
entry is in use (since the previous patch).
We have to initialize them to NULL to ensure we don't work with junk
data and trigger false BUG_ONs.
Signed-off-by: Amit Shah <amit.shah@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Shirley Ma <xma@us.ibm.com>
