Fix a hole in the VFP thread migration. Lets define two threads.
Thread 1, we'll call 'interesting_thread' which is a thread which is
running on CPU0, using VFP (so vfp_current_hw_state[0] =
&interesting_thread->vfpstate) and gets migrated off to CPU1, where
it continues execution of VFP instructions.
Thread 2, we'll call 'new_cpu0_thread' which is the thread which takes
over on CPU0. This has also been using VFP, and last used VFP on CPU0,
but doesn't use it again.
The following code will be executed twice:
cpu = thread->cpu;
/*
* On SMP, if VFP is enabled, save the old state in
* case the thread migrates to a different CPU. The
* restoring is done lazily.
*/
if ((fpexc & FPEXC_EN) && vfp_current_hw_state[cpu]) {
vfp_save_state(vfp_current_hw_state[cpu], fpexc);
vfp_current_hw_state[cpu]->hard.cpu = cpu;
}
/*
* Thread migration, just force the reloading of the
* state on the new CPU in case the VFP registers
* contain stale data.
*/
if (thread->vfpstate.hard.cpu != cpu)
vfp_current_hw_state[cpu] = NULL;
The first execution will be on CPU0 to switch away from 'interesting_thread'.
interesting_thread->cpu will be 0.
So, vfp_current_hw_state[0] points at interesting_thread->vfpstate.
The hardware state will be saved, along with the CPU number (0) that
it was executing on.
'thread' will be 'new_cpu0_thread' with new_cpu0_thread->cpu = 0.
Also, because it was executing on CPU0, new_cpu0_thread->vfpstate.hard.cpu = 0,
and so the thread migration check is not triggered.
This means that vfp_current_hw_state[0] remains pointing at interesting_thread.
The second execution will be on CPU1 to switch _to_ 'interesting_thread'.
So, 'thread' will be 'interesting_thread' and interesting_thread->cpu now
will be 1. The previous thread executing on CPU1 is not relevant to this
so we shall ignore that.
We get to the thread migration check. Here, we discover that
interesting_thread->vfpstate.hard.cpu = 0, yet interesting_thread->cpu is
now 1, indicating thread migration. We set vfp_current_hw_state[1] to
NULL.
So, at this point vfp_current_hw_state[] contains the following:
[0] = &interesting_thread->vfpstate
[1] = NULL
Our interesting thread now executes a VFP instruction, takes a fault
which loads the state into the VFP hardware. Now, through the assembly
we now have:
[0] = &interesting_thread->vfpstate
[1] = &interesting_thread->vfpstate
CPU1 stops due to ptrace (and so saves its VFP state) using the thread
switch code above), and CPU0 calls vfp_sync_hwstate().
if (vfp_current_hw_state[cpu] == &thread->vfpstate) {
vfp_save_state(&thread->vfpstate, fpexc | FPEXC_EN);
BANG, we corrupt interesting_thread's VFP state by overwriting the
more up-to-date state saved by CPU1 with the old VFP state from CPU0.
Fix this by ensuring that we have sane semantics for the various state
describing variables:
1. vfp_current_hw_state[] points to the current owner of the context
information stored in each CPUs hardware, or NULL if that state
information is invalid.
2. thread->vfpstate.hard.cpu always contains the most recent CPU number
which the state was loaded into or NR_CPUS if no CPU owns the state.
So, for a particular CPU to be a valid owner of the VFP state for a
particular thread t, two things must be true:
vfp_current_hw_state[cpu] == &t->vfpstate && t->vfpstate.hard.cpu == cpu.
and that is valid from the moment a CPU loads the saved VFP context
into the hardware. This gives clear and consistent semantics to
interpreting these variables.
This patch also fixes thread copying, ensuring that t->vfpstate.hard.cpu
is invalidated, otherwise CPU0 may believe it was the last owner. The
hole can happen thus:
- thread1 runs on CPU2 using VFP, migrates to CPU3, exits and thread_info
freed.
- New thread allocated from a previously running thread on CPU2, reusing
memory for thread1 and copying vfp.hard.cpu.
At this point, the following are true:
new_thread1->vfpstate.hard.cpu == 2
&new_thread1->vfpstate == vfp_current_hw_state[2]
Lastly, this also addresses thread flushing in a similar way to thread
copying. Hole is:
- thread runs on CPU0, using VFP, migrates to CPU1 but does not use VFP.
- thread calls execve(), so thread flush happens, leaving
vfp_current_hw_state[0] intact. This vfpstate is memset to 0 causing
thread->vfpstate.hard.cpu = 0.
- thread migrates back to CPU0 before using VFP.
At this point, the following are true:
thread->vfpstate.hard.cpu == 0
&thread->vfpstate == vfp_current_hw_state[0]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rename this branch to more accurately reflect why its taken, rather
than what the following code does. It is the only caller of this code.
This helps to clarify following changes, yet this change results in no
actual code change.
Document the VFP hardware state at the target of this branch.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rename the slightly confusing 'last_VFP_context' variable to be more
descriptive of what it actually is. This variable stores a pointer
to the current owner's vfpstate structure for the context held in the
VFP hardware.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'at91/fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/linux-2.6-arm-soc:
AT91: Change nand buswidth logic to match hardware default configuration
at91: Use "pclk" as con_id on at91cap9 and at91rm9200
at91: fix udc, ehci and mmc clock device name for cap9/9g45/9rl
atmel_serial: fix internal port num
at91: fix at91_set_serial_console: use platform device id
Commits 71c29bd5c2 ("IB/uverbs: Add devnode method to set path/mode")
and c3af0980ce ("IB: Add devnode methods to cm_class and umad_class")
added devnode methods that set the mode.
However, these methods don't check for a NULL mode, and so we get a
crash when unloading modules because devtmpfs_delete_node() calls
device_get_devnode() with mode == NULL.
Add the missing checks.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
[ Also fix cm.c. - Roland ]
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The recently modified nand buswitth configuration is not aligned with
board reality: the double footprint on boards is always populated with 8bits
buswidth nand flashes.
So we have to consider that without particular configuration the 8bits
buswidth is selected by default.
Moreover, the previous logic was always using !board_have_nand_8bit(), we
change it to a simpler: board_have_nand_16bit().
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Ludovic Desroches <ludovic.desroches@atmel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
When releasing framebuffer, free colourmap allocations.
Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
* 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
hwmon: (k10temp) Update documentation for Fam12h
hwmon-vid: Fix typo in VIA CPU name
hwmon: (f71882fg) Add support for the F71869A
hwmon: Use <> rather than () around my e-mail address
hwmon: (emc6w201) Properly handle all errors
Add some CPU series IDs and links to the Fam12h datasheets.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
The F71869A is almost the same as the F71869F/E, except that it has
the normal number of temp and pwm zones for a F71882FG derived chip,
rather then the limited number of the F71869F/E.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Max Baldwin <archerseven@gmail.com>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Handle errors on 8-bit register reads and writes too. Also use likely
and unlikely to make the functions faster on success.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Guenter Roeck <guenter.roeck@ericsson.com>
The hard_reset parameter passed to the LLDD in the direct-attached
phy control case allows the LLDD to filter link failure events
while the direct-attached device reset is executing.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The messages emitted from task.c and some from request.c likely
duplicate (in a less undertandable way) what is reported by the
midlayer.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Perform checking per-pci device (even though all systems will only have
1 pci device in this generation), and delete support for silicon that
does not report a proper revision (i.e. A0).
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Most of these simple dereference macros are longer than their open coded
equivalent. Deleting enum sci_controller_mode is thrown in for good
measure.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The distinction between scic_sds_ scic_ and sci_ are no longer relevant
so just unify the prefixes on sci_. The distinction between isci_ and
sci_ is historically significant, and useful for comparing the old
'core' to the current Linux driver. 'sci_' represents the former core as
well as the routines that are closer to the hardware and protocol than
their 'isci_' brethren. sci == sas controller interface.
Also unwind the 'sds1' out of the parameter structs.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Remove the distinction between these two implementations and unify on
isci_host (local instances named ihost). Hmmm, we had two
'oem_parameters' instances, one was unused... nice.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Remove the distinction between these two implementations and unify on
isci_remote_device (local instances named idev).
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Remove the distinction between these two implementations and unify on
isci_port (local instances named iport). The duplicate '->owning_port' and
'->isci_port' in both isci_phy and isci_remote_device will be fixed in a later
patch... this is just the straightforward rename/unification.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Commit 0815632 "isci: unify remote_device stop_handlers" introduced the
possibility that not all requests get terminated if we reach the
request_count. Now that we properly reference count devices we don't
need this self-defense and can do the straightforward scan of all active
requests.
Reported-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Acked-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
They are one in the same object so remove the distinction. The near
duplicate fields (owning_port, and isci_port) will be cleaned up
after the scic_sds_port isci_port unification.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
They are one in the same object so remove the distinction. The near
duplicate fields (owning_controller, and isci_host) will be cleaned up
after the scic_sds_contoller isci_host unification.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
* Rename scic_sds_stp_request to isci_stp_request
* Remove the unused fields and union indirection
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
the dma_pool interface is optimized for object_size << page_size which
is not the case with isci_request objects and the dma_pool routines show
up in the top of the profile.
The old io_request_table which tracked whether tci slots were in-flight
or not is replaced with an IREQ_ACTIVE flag per request.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Combine three bools into one unsigned long 'flags'. Doesn't increase the
request size due to packing. (to do: optimize the structure layout).
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
The tci_pool tracks our outstanding command slots which are also the 'index'
portion of our tags. Grabbing the tag early in ->lldd_execute_task let's us
drop the isci_host_can_queue() and ->was_tag_assigned_by_user infrastructure.
->was_tag_assigned_by_user required the task context to be duplicated in
request-local buffer. With the tci established early we can build the
task_context directly into its final location and skip a memcpy.
With the task context buffer at a known address at request construction we
have the opportunity/obligation to also fix sgl handling. This rework feels
like it belongs in another patch but the sgl handling and task_context are too
intertwined.
1/ fix the 'ab' pair embedded in the task context to point to the 'cd' pair in
the task context (previously we were prematurely linking to the staging
buffer).
2/ fix the broken iteration of pio sgls that assumes all sgls are relative to
the request, and does a dangerous looking reverse lookup of physical
address to virtual address.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
When the remote device transitions to a not-ready state because of
an NCQ error condition, all outstanding requests to that device
are terminated and completed to libsas on the normal path. The
device then waits for a READ LOG EXT command to issue on the task
management path.
Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Updates to the frame_rcvd before need to be atomic with respect to when
they are evaluated by libsas.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
scu_index is a parameter of isci_parse_eom_parameters and is an index
in controller table. There is a check: scu_index > SCI_MAX_CONTROLLERS
which is insufficient and should be: scu_index >= SCI_MAX_CONTROLLERS.
scu_index is used as an index in the table which size is
SCI_MAX_CONTROLLERS.
Signed-off-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
1/ fix the timeout for wait_for_completion_timeout
2/ In the tmf timeout case we need to wait for our termination callback
3/ Once the request is successfully started it will be freed according to the
normal lifetime for requests.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Instead of duplicating the smp request buffer reuse the one provided by
libsas. This future proofs the driver to support arbitrarily large smp
requests, and shrinks the request structure size by ~700 bytes.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
One bug and a cleanup:
1/ Fix cases where we were unmapping invalid addresses (smp requests were
being unmapped)
[ 604.662770] ------------[ cut here ]------------
[ 604.668026] WARNING: at lib/dma-debug.c:800 check_unmap+0x418/0x740()
[ 604.675315] Hardware name: SandyBridge Platform
[ 604.680465] isci 0000:03:00.0: DMA-API: device driver tries to free an invalid DMA memory address
2/ The unmap routine is too large to be an inline function, and
isci_request_io_request_get_next_sge is unused.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Due to a typo we currently copy way too much when copying over the
response data, but since a request is likely backed by a full page
allocation we don't corrupt live data.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Now that we have upleveled device reassignment protection to the
isci_remote_device reference count we no longer need this level of
self-defense.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Now that "stopping/stopped" are one in the same and signalled by a NULL device
pointer the rest of the device status infrastructure can be removed (->status
and ->state_lock). The "not ready for i/o state" is replaced with a state
flag, and is evaluated under scic_lock so that we don't see transients from
taking the device reference to submitting the i/o.
This also fixes a potential leakage of can_queue slots in the rare case that
SAS_TASK_ABORTED is set at submission.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
We have unsafe references to remote devices that are notified to
disappear at lldd_dev_gone. In order to clean this up we need a single
canonical source for device lookups and stable references once a lookup
succeeds. Towards that end guarantee that domain_device.lldd_dev is
NULL as soon as we start the process of stopping a device. Any code
path that wants to safely lookup a remote device must do so through
task->dev->lldd_dev (isci_lookup_device()).
For in-flight references outside of scic_lock we need reference counting
to ensure that the device is not recycled before we are done with it.
Simplify device back references to just scic_sds_request.target_device
which is now the only permissible internal reference that is maintained
relative to the reference count.
There were two occasions where we wanted new i/o's to be treated as
SAS_TASK_UNDELIVERED but where the domain_dev->lldd_dev link is still
intact. Introduce a 'gone' flag to prevent i/o while waiting for libsas
to take action on the port down event.
One 'core' leftover is that we currently call
scic_remote_device_destruct() from isci_remote_device_deconstruct()
which is called when the 'core' says the device is stopped. It would be
more natural for the final put to trigger
isci_remote_device_deconstruct() but this implementation is deferred as
it requires other changes.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
In isci_task_request_complete() we save the response/sense data from the
command. Make sure isci_tmf has enough space to hold the full response.
[ it does not look like we actually use this data, and
response_data_len/sense_data_len should be specifying the byte count,
in any event do the simple fix first so we don't corrupt memory ]
Reported-by: Adam Gruchala <adam.gruchala@intel.com>
Tested-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Rather than return an error code and update a pointer that was passed by
reference just return the request object directly (or null if allocation
failed).
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Every single i/o or event completion incurs a test and branch to see if
the cycle bit changed. For power-of-2 queue sizes the cycle bit can be
read directly from the rollover of the queue pointer.
Likely premature optimization, but the hidden if() and hidden
assignments / side-effects in the macros were already asking to be
cleaned up.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
