According to the reference manuals for the corresponding SoCs, SEC
frequency ratio configuration is indicated by bit 26 of the POR Device
Status Register 2. Consequently, SEC_CFG bit should be tested by mask 0x20,
not 0x80. Testing the wrong bit leads to selection of wrong I2C clock
prescaler on those SoCs.
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The 9P of Xen module is missing required license and module information.
See https://bugzilla.kernel.org/show_bug.cgi?id=198109
Reported-by: Alan Bartlett <ajb@elrepo.org>
Fixes: 868eb12273 ("xen/9pfs: introduce Xen 9pfs transport driver")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 8ce795cb0c ("i2c: mpc: assign the correct prescaler from SVR")
introduced the common helper function for obtaining the actual clock
prescaler value for MPC85xx. However, getting the prescaler for MPC8544
which depends on the SEC frequency ratio on this platform, has been always
performed separately based on the corresponding Device Tree configuration.
Move special handling of MPC8544 into that common helper. Make it dependent
on the SoC version and not on Device Tree compatible node, as is the case
with all other SoCs. Handle MPC8533 the same way which is similar
to MPC8544 in this regard, according to AN2919 "Determining the I2C
Frequency Divider Ratio for SCL".
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Obtaining the actual I2C clock prescaler value in mpc_i2c_setup_8xxx() only
happens when the clock parameter is set to something other than
MPC_I2C_CLOCK_LEGACY. When the clock parameter is exactly
MPC_I2C_CLOCK_LEGACY, the prescaler parameter is used in arithmetic
division as provided by the caller, resulting in a division by zero
for the majority of processors supported by the module.
Avoid division by zero by obtaining the actual I2C clock prescaler
in mpc_i2c_setup_8xxx() unconditionally regardless of the passed clock
value.
Signed-off-by: Arseny Solokha <asolokha@kb.kras.ru>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
We set dsu_pmu->num_counters to -1, when the DSU is allocated
but not initialised when none of the CPUs are active in the DSU.
However, we use an unsigned field for num_counters. Switch this
to a signed field.
Fixes: 7520fa9924 ("perf: ARM DynamIQ Shared Unit PMU support")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Sometimes a single capability could be listed multiple times with
differing matches(), e.g, CPU errata for different MIDR versions.
This breaks verify_local_cpu_feature() and this_cpu_has_cap() as
we stop checking for a capability on a CPU with the first
entry in the given table, which is not sufficient. Make sure we
run the checks for all entries of the same capability. We do
this by fixing __this_cpu_has_cap() to run through all the
entries in the given table for a match and reuse it for
verify_local_cpu_feature().
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
__phy_modify would return the old value of the register before it was
modified. Thus on success, it does not return 0, but a positive value.
Thus functions using phy_modify, which is a wrapper around
__phy_modify, can start returning > 0 on success, rather than 0. As a
result, breakage has been noticed in various places, where 0 was
assumed.
Code inspection does not find any current location where the return of
the old value is currently used. So have __phy_modify return 0 on
success. When there is a real need for the old value, either a new
accessor can be added, or an additional parameter passed.
Fixes: fea23fb591 ("net: phy: convert read-modify-write to phy_modify()")
Fixes: 2b74e5be17 ("net: phy: add phy_modify() accessor")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The installed resource table is no longer accessible after stopping the
remote, so update table_ptr to point to the local copy.
Reviewed-By: Loic Pallardy <loic.pallardy@st.com>
Tested-By: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
As the core now deals with the lack of a resource table, remove the
dangling custom dummy implementations of find_rsc_table from drivers.
Reviewed-By: Loic Pallardy <loic.pallardy@st.com>
Tested-By: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Extend the previous operation of finding the resource table in the ELF
with the extra step of populating the rproc struct with a copy and the
size. This allows drivers to override the mechanism used for acquiring
the resource table, or omit it for firmware that is known not to have a
resource table.
This leaves the custom, dummy, find_rsc_table implementations found in
some drivers dangling.
Reviewed-By: Loic Pallardy <loic.pallardy@st.com>
Tested-By: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Allow a NULL table_ptr to have the same meaning as a table with 0
entries, allowing a subsequent patch to skip the assignment step.
A few other places in the implementation does dereference table_ptr, but
they are currently all coming from rproc_handle_resources().
Reviewed-By: Loic Pallardy <loic.pallardy@st.com>
Tested-By: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
There are currently a few different schemes used for overriding fw_ops
or parts of fw_ops. Merge fw_ops into rproc_ops and expose the default
ELF-loader symbols so that they can be assigned by the drivers.
To keep backwards compatibility with the "default" case, a driver not
specifying the "load" operation is assumed to want the full ELF-loader
suit of functions.
Reviewed-By: Loic Pallardy <loic.pallardy@st.com>
Tested-By: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
In order to allow rproc_alloc() to, in a future patch, update entries in
the "ops" struct we need to make a local copy of it.
Reviewed-By: Loic Pallardy <loic.pallardy@st.com>
Tested-By: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
We don't re-read the resource table during a recovery, so it is possible
in the recovery path that the resource table has a different size than
cached_table. Store the original size of cached_table to avoid these
getting out of sync.
Reviewed-By: Loic Pallardy <loic.pallardy@st.com>
Tested-By: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
The crash handling now happens in a single execution context, so there's
no longer a need for a completion to synchronize this.
Reviewed-By: Loic Pallardy <loic.pallardy@st.com>
Tested-By: Loic Pallardy <loic.pallardy@st.com>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Commit 1a149d7d3f ("ring-buffer: Rewrite trace_recursive_(un)lock() to be
simpler") replaced the context level recursion checks with a simple counter.
This would prevent the ring buffer code from recursively calling itself more
than the max number of contexts that exist (Normal, softirq, irq, nmi). But
this change caused a lockup in a specific case, which was during suspend and
resume using a global clock. Adding a stack dump to see where this occurred,
the issue was in the trace global clock itself:
trace_buffer_lock_reserve+0x1c/0x50
__trace_graph_entry+0x2d/0x90
trace_graph_entry+0xe8/0x200
prepare_ftrace_return+0x69/0xc0
ftrace_graph_caller+0x78/0xa8
queued_spin_lock_slowpath+0x5/0x1d0
trace_clock_global+0xb0/0xc0
ring_buffer_lock_reserve+0xf9/0x390
The function graph tracer traced queued_spin_lock_slowpath that was called
by trace_clock_global. This pointed out that the trace_clock_global() is not
reentrant, as it takes a spin lock. It depended on the ring buffer recursive
lock from letting that happen.
By removing the context detection and adding just a max number of allowable
recursions, it allowed the trace_clock_global() to be entered again and try
to retake the spinlock it already held, causing a deadlock.
Fixes: 1a149d7d3f ("ring-buffer: Rewrite trace_recursive_(un)lock() to be simpler")
Reported-by: David Weinehall <david.weinehall@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This patch dumps general and master registers at the end of transactions
when debugging is enabled. Previously, registers were only dumped before
submitting new descriptors (at the beginning of transactions).
This helps debugging if some registers change as result of a failed
transaction (e.g. bits are set in the ERRSTS general register).
Signed-off-by: Radu Rendec <radu.rendec@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Make use of the new formula for more precise bus frequencies.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The formula to generate the desired bus speeds has changed a little over
time. Implement the new formula and allow drivers to opt-in by changing
to this new config set. Ensure in probe that we don't divide by zero.
The returned values on a R-Car H2 (r8a7790/Lager board) match the
suggested values in the datasheet.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Because we will add a second formula soon, put the sanity checks for the
computed results into a separate function.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Start RuntimePM a bit earlier, so we can use it to enable the clock
during probe for frequency calculations. Make sure it is enabled before
calling setup().
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Require the setup callback and move the frequency calculation into it.
This is in preparation for supporting multiple formulas.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The setup callback will be more generic and, thus, need to be able to
return error codes. Change the return type to 'int' for that.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
For refactoring reasons, we will need this information before the setup
callback. Also, simplify the comment to a oneliner.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Building jailhouse support without PCI results in a link error:
arch/x86/kernel/jailhouse.o: In function `jailhouse_init_platform':
jailhouse.c:(.init.text+0x235): undefined reference to `pci_probe'
arch/x86/kernel/jailhouse.o: In function `jailhouse_pci_arch_init':
jailhouse.c:(.init.text+0x265): undefined reference to `pci_direct_init'
jailhouse.c:(.init.text+0x26c): undefined reference to `pcibios_last_bus'
Add the missing Kconfig dependency.
Fixes: a0c01e4bb9 ("x86/jailhouse: Initialize PCI support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Link: https://lkml.kernel.org/r/20180115155150.51407-1-arnd@arndb.de
Tegra host driver is using pci_find_host_bridge() to get private data;
this can be easily avoided by using bus->sysdata to store and get private
data removing the pci_find_host_bridge() dependency.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
[lorenzo.pieralisi@arm.com: rewrote commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Some PCIe host drivers parse of_pci_range from device tree and convert
it to resources. Export of_pci_range_to_resource() to allow PCIe host
drivers to be compiled as loadable kernel module.
Signed-off-by: Manikanta Maddireddy <mmaddireddy@nvidia.com>
[lorenzo.pieralisi@arm.com: rewrote commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
acpi_lpss_create_device() skips handling LPSS devices which do not have
a mmio resources in their resource list (typically these devices are
disabled by the firmware). But since the LPSS code does not bind to the
device, acpi_bus_attach() ends up still creating a platform device for
it and the regular platform_driver for the ACPI HID still tries to bind
to it.
This happens e.g. on some boards which do not use the pwm-controller
and have an empty or invalid resource-table for it. Currently this causes
these error messages to get logged:
[ 3.281966] pwm-lpss 80862288:00: invalid resource
[ 3.287098] pwm-lpss: probe of 80862288:00 failed with error -22
This commit stops the undesirable creation of a platform_device for
disabled LPSS devices by setting pnp.type.platform_id to 0. Note that
acpi_scan_attach_handler() also sets pnp.type.platform_id to 0 when there
is a matching handler for the device and that handler has no attach
callback, so we simply behave as a handler without an attach function
in this case.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Modify pm_runtime_need_not_resume() to make it avoid taking
power.child_count for devices with power.ignore_children which
is consistent with the runtime PM usage of these fields.
Suggested-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
nvmet_req_init looked up a namespace and took a reference on it (unless it
failed prior to that). If the request is uninitialized (in error cases) we
need to remove that reference in case it was taken, otherwise we leak
namespace reference when calling nvme_req_uninit.
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
We use match_strdup() to get a copy of the option string for host ID string, but
we just pass it to uuid_parse() and don't store the string pointer, so we need to
kfree() the string after parsing it.
Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
fix comment typos in nvme_create_io_queues() like below.
_aount_ to _amount_
_an_ to _can_
Signed-off-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Kbuild complains about the lack of a license tag in this driver:
WARNING: modpost: missing MODULE_LICENSE() in drivers/video/fbdev/mmp/mmp_disp.o
This adds the license, author and description tags.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
When this method is set, the caller expects struct console_font fields
to be properly initialized when it returns. Leave it unset otherwise
nonsensical (leaked kernel stack) values are returned to user space.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
framebuffer_alloc allocated the fb_info struct plus the extra
par and set fb_info->par pointer equal to this extra par. We
can refer the mxcfb_info from fb_info->par
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Tested-by: Stefan Agner <stefan@agner.ch>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Variable 'dev' is usually used for 'struct device'. Therefore
rename driver private data to dlfb to avoid confusion once
driver will be using dev_*() logging functions.
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Cc: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
These warnings comes from times of driver development and do
not carry any usefull debugging information.
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Cc: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
gdev is not really needed as the same content can be read
from udev->dev.
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Cc: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
'urb' is not needed and can be removed.
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Cc: Bernie Thompson <bernie@plugable.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Initialize data->config_lock mutex before it is used by the driver code.
This fixes following warning on Odroid XU3 boards:
INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 5 PID: 1 Comm: swapper/0 Not tainted 4.15.0-rc7-next-20180115-00001-gb75575dee3f2 #107
Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[<c0111504>] (unwind_backtrace) from [<c010dbec>] (show_stack+0x10/0x14)
[<c010dbec>] (show_stack) from [<c09b3f74>] (dump_stack+0x90/0xc8)
[<c09b3f74>] (dump_stack) from [<c0179528>] (register_lock_class+0x1c0/0x59c)
[<c0179528>] (register_lock_class) from [<c017bd1c>] (__lock_acquire+0x78/0x1850)
[<c017bd1c>] (__lock_acquire) from [<c017de30>] (lock_acquire+0xc8/0x2b8)
[<c017de30>] (lock_acquire) from [<c09ca59c>] (__mutex_lock+0x60/0xa0c)
[<c09ca59c>] (__mutex_lock) from [<c09cafd0>] (mutex_lock_nested+0x1c/0x24)
[<c09cafd0>] (mutex_lock_nested) from [<c068b0d0>] (ina2xx_set_shunt+0x70/0xb0)
[<c068b0d0>] (ina2xx_set_shunt) from [<c068b218>] (ina2xx_probe+0x88/0x1b0)
[<c068b218>] (ina2xx_probe) from [<c0673d90>] (i2c_device_probe+0x1e0/0x2d0)
[<c0673d90>] (i2c_device_probe) from [<c053a268>] (driver_probe_device+0x2b8/0x4a0)
[<c053a268>] (driver_probe_device) from [<c053a54c>] (__driver_attach+0xfc/0x120)
[<c053a54c>] (__driver_attach) from [<c05384cc>] (bus_for_each_dev+0x58/0x7c)
[<c05384cc>] (bus_for_each_dev) from [<c0539590>] (bus_add_driver+0x174/0x250)
[<c0539590>] (bus_add_driver) from [<c053b5e0>] (driver_register+0x78/0xf4)
[<c053b5e0>] (driver_register) from [<c0675ef0>] (i2c_register_driver+0x38/0xa8)
[<c0675ef0>] (i2c_register_driver) from [<c0102b40>] (do_one_initcall+0x48/0x18c)
[<c0102b40>] (do_one_initcall) from [<c0e00df0>] (kernel_init_freeable+0x110/0x1d4)
[<c0e00df0>] (kernel_init_freeable) from [<c09c8120>] (kernel_init+0x8/0x114)
[<c09c8120>] (kernel_init) from [<c01010b4>] (ret_from_fork+0x14/0x20)
Fixes: 5d389b1251 ("hwmon: (ina2xx) Make calibration register value fixed")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
DM is no longer prone to having its request_queue be improperly
initialized.
Summary of changes:
- defer DM's blk_register_queue() from add_disk()-time until
dm_setup_md_queue() by using add_disk_no_queue_reg() in alloc_dev().
- dm_setup_md_queue() is updated to fully initialize DM's request_queue
(_after_ all table loads have occurred and the request_queue's type,
features and limits are known).
A very welcome side-effect of these changes is DM no longer needs to:
1) backfill the "mq" sysfs entry (because historically DM didn't
initialize the request_queue to use blk-mq until _after_
blk_register_queue() was called via add_disk()).
2) call elv_register_queue() to get .request_fn request-based DM
device's "iosched" exposed in syfs.
In addition, blk-mq debugfs support is now made available because
request-based DM's blk-mq request_queue is now properly initialized
before dm_setup_md_queue() calls blk_register_queue().
These changes also stave off the need to introduce new DM-specific
workarounds in block core, e.g. this proposal:
https://patchwork.kernel.org/patch/10067961/
In the end DM devices should be less unicorn in nature (relative to
initialization and availability of block core infrastructure provided by
the request_queue).
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Tested-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
During stress tests by syzkaller on the sg driver the block layer
infrequently returns EINVAL. Closer inspection shows the block
layer was trying to return ENOMEM (which is much more
understandable) but for some reason overroad that useful error.
Patch below does not show this (unchanged) line:
ret =__blk_rq_map_user_iov(rq, map_data, &i, gfp_mask, copy);
That 'ret' was being overridden when that function failed.
Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO ioctl sets the tempo and the ppq
in a single call, while the current implementation updates each value
one by one. This is a bit racy, and also suboptimal from the
performance POV, as each call does re-acquire the lock and invokes
the update of ALSA timer resolution.
This patch reorganizes the code slightly so that we change both the
tempo and the ppq in a shot. The skew value can be put into the same
lock, but this is rather a rarely used feature and completely
independent from the temp/ppq (it's evaluated only in the interrupt),
so it's left as it was.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Since I can remember DM has forced the block layer to allow the
allocation and initialization of the request_queue to be distinct
operations. Reason for this is block/genhd.c:add_disk() has requires
that the request_queue (and associated bdi) be tied to the gendisk
before add_disk() is called -- because add_disk() also deals with
exposing the request_queue via blk_register_queue().
DM's dynamic creation of arbitrary device types (and associated
request_queue types) requires the DM device's gendisk be available so
that DM table loads can establish a master/slave relationship with
subordinate devices that are referenced by loaded DM tables -- using
bd_link_disk_holder(). But until these DM tables, and their associated
subordinate devices, are known DM cannot know what type of request_queue
it needs -- nor what its queue_limits should be.
This chicken and egg scenario has created all manner of problems for DM
and, at times, the block layer.
Summary of changes:
- Add device_add_disk_no_queue_reg() and add_disk_no_queue_reg() variant
that drivers may use to add a disk without also calling
blk_register_queue(). Driver must call blk_register_queue() once its
request_queue is fully initialized.
- Return early from blk_unregister_queue() if QUEUE_FLAG_REGISTERED
is not set. It won't be set if driver used add_disk_no_queue_reg()
but driver encounters an error and must del_gendisk() before calling
blk_register_queue().
- Export blk_register_queue().
These changes allow DM to use add_disk_no_queue_reg() to anchor its
gendisk as the "master" for master/slave relationships DM must establish
with subordinate devices referenced in DM tables that get loaded. Once
all "slave" devices for a DM device are known its request_queue can be
properly initialized and then advertised via sysfs -- important
improvement being that no request_queue resource initialization
performed by blk_register_queue() is missed for DM devices anymore.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The original commit e9a823fb34 (block: fix warning when I/O elevator
is changed as request_queue is being removed) is pretty conflated.
"conflated" because the resource being protected by q->sysfs_lock isn't
the queue_flags (it is the 'queue' kobj).
q->sysfs_lock serializes __elevator_change() (via elv_iosched_store)
from racing with blk_unregister_queue():
1) By holding q->sysfs_lock first, __elevator_change() can complete
before a racing blk_unregister_queue().
2) Conversely, __elevator_change() is testing for QUEUE_FLAG_REGISTERED
in case elv_iosched_store() loses the race with blk_unregister_queue(),
it needs a way to know the 'queue' kobj isn't there.
Expand the scope of blk_unregister_queue()'s q->sysfs_lock use so it is
held until after the 'queue' kobj is removed.
To do so blk_mq_unregister_dev() must not also take q->sysfs_lock. So
rename __blk_mq_unregister_dev() to blk_mq_unregister_dev().
Also, blk_unregister_queue() should use q->queue_lock to protect against
any concurrent writes to q->queue_flags -- even though chances are the
queue is being cleaned up so no concurrent writes are likely.
Fixes: e9a823fb34 ("block: fix warning when I/O elevator is changed as request_queue is being removed")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
device_add_disk() will only call bdi_register_owner() if
!GENHD_FL_HIDDEN, so it follows that del_gendisk() should only call
bdi_unregister() if !GENHD_FL_HIDDEN.
Found with code inspection. bdi_unregister() won't do any harm if
bdi_register_owner() wasn't used but best to avoid the unnecessary
call to bdi_unregister().
Fixes: 8ddcd65325 ("block: introduce GENHD_FL_HIDDEN")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
