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A long time ago, GITS_CTLR[1] used to be called GITC_CTLR.EnableVLPI.
It has been subsequently deprecated and is now an "Implementation
Defined" bit that may ot may not be set for GICv4. Brilliant.
And the current crop of the FastModel requires that bit for VLPIs
to be enabled. Oh well... Let's set it and find out what breaks.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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When we don't have the DirectLPI feature, we must work around the
architecture shortcomings to be able to perform the required
maintenance (interrupt masking, clearing and injection).
For this, we create a fake device whose sole purpose is to
provide a way to issue commands as if we were dealing with LPIs
coming from that device (while they actually originate from
the ITS). This fake device doesn't have LPIs allocated to it,
but instead uses the VPE LPIs.
Of course, this could be a real bottleneck, and a naive
implementation would require 6 commands to issue an invalidation.
Instead, let's allocate at least one event per physical CPU
(rounded up to the next power of 2), and opportunistically
map the VPE doorbell to an event. This doorbell will be mapped
until we roll over and need to reallocate this slot.
This ensures that most of the time, we only need 2 commands
to issue an INV, INT or CLEAR, making the performance a lot
better, given that we always issue a CLEAR on entry, and
an INV on each side of a trapped WFI.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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When a VPE is scheduled to run, the corresponding redistributor must
be told so, by setting VPROPBASER to the VM's property table, and
VPENDBASER to the vcpu's pending table.
When scheduled out, we preserve the IDAI and PendingLast bits. The
latter is specially important, as it tells the hypervisor that
there are pending interrupts for this vcpu.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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V{PEND,PROP}BASER being 64bit registers, they need some ad-hoc
accessors on 32bit, specially given that VPENDBASER contains
a Valid bit, making the access a bit convoluted.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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Add the new GICv4 ITS command definitions, most of them, being
defined in terms of their physical counterparts.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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Add a bunch of GICv4-specific data structures that will get used in
subsequent patches.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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Signed-off-by: Ingo Molnar <mingo@kernel.org>
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In some scenarios, we should set some pins as input/output/pullup/pulldown
when the specified system goes into deep sleep mode, then when the system
goes into deep sleep mode, these pins will be set automatically by hardware.
That means some pins are not controlled by any specific driver in the OS, but
need to be controlled when entering sleep mode. Thus we introduce one sleep
state config into pinconf-generic for users to configure.
Signed-off-by: Baolin Wang <baolin.wang@spreadtrum.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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Add TX offloads support for GRE tunneled packets by reporting the needed
netdev features.
Signed-off-by: Gal Pressman <galp@mellanox.com>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
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This patch adds more generic PHY modes to the phy_mode enum, to
allow configuring generic PHYs to the SGMII and/or the 10GKR mode
by using the set_mode callback.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The following new APIs are added:
int idr_alloc_ext(struct idr *idr, void *ptr, unsigned long *index,
unsigned long start, unsigned long end, gfp_t gfp);
void *idr_remove_ext(struct idr *idr, unsigned long id);
void *idr_find_ext(const struct idr *idr, unsigned long id);
void *idr_replace_ext(struct idr *idr, void *ptr, unsigned long id);
void *idr_get_next_ext(struct idr *idr, unsigned long *nextid);
Signed-off-by: Chris Mi <chrism@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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MLX5_INTERFACE_STATE_SHUTDOWN is not used in the code.
Fixes: 5fc7197d3a25 ("net/mlx5: Add pci shutdown callback")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
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There is an issue where the firmware fails during mlx5_load_one,
the health_care timer detects the issue and schedules a health_care call.
Then the mlx5_load_one detects the issue, cleans up and quits. Then
the health_care starts and calls mlx5_unload_one to clean up the resources
that no longer exist and causes kernel panic.
The root cause is that the bit MLX5_INTERFACE_STATE_DOWN is not set
after mlx5_load_one fails. The solution is removing the bit
MLX5_INTERFACE_STATE_DOWN and quit mlx5_unload_one if the
bit MLX5_INTERFACE_STATE_UP is not set. The bit MLX5_INTERFACE_STATE_DOWN
is redundant and we can use MLX5_INTERFACE_STATE_UP instead.
Fixes: 5fc7197d3a25 ("net/mlx5: Add pci shutdown callback")
Signed-off-by: Huy Nguyen <huyn@mellanox.com>
Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
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This reverts commit 45f119bf936b1f9f546a0b139c5b56f9bb2bdc78.
Eric Dumazet says:
We found at Google a significant regression caused by
45f119bf936b1f9f546a0b139c5b56f9bb2bdc78 tcp: remove header prediction
In typical RPC (TCP_RR), when a TCP socket receives data, we now call
tcp_ack() while we used to not call it.
This touches enough cache lines to cause a slowdown.
so problem does not seem to be HP removal itself but the tcp_ack()
call. Therefore, it might be possible to remove HP after all, provided
one finds a way to elide tcp_ack for most cases.
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a helper that can replace the following common pattern:
if (blk_queue_dax(bdev->bd_queue))
fs_dax_get_by_host(bdev->bd_disk->disk_name);
This will be used to move dax_device lookup from iomap-operation time to
fs-mount time.
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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With the current IOMMU-API the hardware TLBs have to be
flushed in every iommu_ops->unmap() call-back.
For unmapping large amounts of address space, like it
happens when a KVM domain with assigned devices is
destroyed, this causes thousands of unnecessary TLB flushes
in the IOMMU hardware because the unmap call-back runs for
every unmapped physical page.
With the TLB Flush Interface and the new iommu_unmap_fast()
function introduced here the need to clean the hardware TLBs
is removed from the unmapping code-path. Users of
iommu_unmap_fast() have to explicitly call the TLB-Flush
functions to sync the page-table changes to the hardware.
Three functions for TLB-Flushes are introduced:
* iommu_flush_tlb_all() - Flushes all TLB entries
associated with that
domain. TLBs entries are
flushed when this function
returns.
* iommu_tlb_range_add() - This will add a given
range to the flush queue
for this domain.
* iommu_tlb_sync() - Flushes all queued ranges from
the hardware TLBs. Returns when
the flush is finished.
The semantic of this interface is intentionally similar to
the iommu_gather_ops from the io-pgtable code.
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
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Register the 5V boost converter as a regulator named "usb_otg_vbus".
This commit also adds support for bq24190_platform_data, through which
non device-tree platforms can pass the regulator_init_data (containing
mappings for the consumer amongst other things).
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
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Pull NVMe fixes from Christoph:
"Three more fixes for 4.13 below:
- fix the incorrect bit for the doorbell buffer features (Changpeng Liu)
- always use a 4k MR page size for RDMA, to not get in trouble with
offset in non-4k page size systems (no-op for x86) (Max Gurtovoy)
- and a fix for the new nvme host memory buffer support to keep the
descriptor list DMA mapped when the buffer is enabled (me)"
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mmc_start_areq() is an internal mmc core API. Move the declaration
accordingly.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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Add CQE host operations, capabilities, and host members.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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NVMe 1.3 specification defines the Optional Admin Command Support feature
flags, bit 8 set to '1' then the controller supports the Doorbell Buffer
Config command. Bit 7 is used for Virtualization Mangement command.
Signed-off-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Fixes: f9f38e33 ("nvme: improve performance for virtual NVMe devices")
Cc: stable@vger.kernel.org
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There are new types and helpers that are supposed to be used in new code.
As a preparation to get rid of legacy types and API functions do
the conversion here.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Most of the information needed to issue requests to a CQE is already in
struct mmc_request and struct mmc_data. Add data block address, some flags,
and the task id (tag), and allow for cmd being NULL which it is for CQE
tasks.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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Packed commands support was removed but some bits got left behind. Remove
them.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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There is one SDHI instance on Gen2 which does not have the CBSY bit.
So, turn CBSY usage into an extra flag and set it accordingly. This has
the additional advantage that we can also set it for other incarnations
later.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Chris Brandt <Chris.Brandt@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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Starting with the A83T SoC, Allwinner introduced a new timing mode for
its MMC clocks. The new mode changes how the MMC controller sample and
output clocks are delayed to match chip and board specifics. There are
two controls for this, one on the CCU side controlling how the clocks
behave, and one in the MMC controller controlling what inputs to take
and how to route them.
In the old mode, the MMC clock had 2 child clocks providing the output
and sample clocks, which could be delayed by a number of clock cycles
measured from the MMC clock's parent.
With the new mode, the 2 delay clocks are no longer active. Instead,
the delays and associated controls are moved into the MMC controller.
The output of the MMC clock is also halved.
The difference in how things are wired between the modes means that the
clock controls and the MMC controls must match. To achieve this in a
clear, explicit way, we introduce two functions for the MMC driver to
use: one queries the hardware for the current mode set, and the other
allows the MMC driver to request a mode.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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Per the spec of JESD84-B51, section 7.3, replace tacc with taac to
fix the obvious typo.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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The intention of this check was to prevent the conflict between
hotplug and removing driver for whatever reason. Currently it
doesn't improve anything and the following rescan process could
still saftly perform the scan flow. So these code seems pointless
now and let's remove them.
Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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Allow TMIO and SDHI driver implementations to provide values for
max_segs and max_blk_count.
A follow-up patch will set these values for Renesas Gen3 SoCs
the using an SDHI driver.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Ai Kyuse <ai.kyuse.uw@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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The glink protocol supports different types of transports (shared
memory). With the core protocol remaining the same, the way the
transport's memory is probed and accessed is different. So add support
for glink's smem based transports.
Adding a new smem transport register function and the fifo accessors for
the same.
Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
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The SAS code will need it. Also mark the name argument const to match
bsg_register_queue.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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A common pattern in RCU code is to assign a new value to an RCU pointer
after having read and stored the old value. Introduce a macro for this
pattern.
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Shane M Seymour <shane.seymour@hpe.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Make the drivers that want to include the polling state into their
states table initialize it explicitly and drop the initialization of
it (which in fact is conditional, but that is not obvious from the
code) from the core.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
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Move the polling state initialization code to a separate file built
conditionally on CONFIG_ARCH_HAS_CPU_RELAX to get rid of the #ifdef
in driver.c.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
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On some architectures the first (index 0) idle state is a polling
one and it doesn't really save energy, so there is the
CPUIDLE_DRIVER_STATE_START symbol allowing some pieces of
cpuidle code to avoid using that state.
However, this makes the code rather hard to follow. It is better
to explicitly avoid the polling state, so add a new cpuidle state
flag CPUIDLE_FLAG_POLLING to mark it and make the relevant code
check that flag for the first state instead of using the
CPUIDLE_DRIVER_STATE_START symbol.
In the ACPI processor driver that cannot always rely on the state
flags (like before the states table has been set up) define
a new internal symbol ACPI_IDLE_STATE_START equivalent to the
CPUIDLE_DRIVER_STATE_START one and drop the latter.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
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Since the removal of NET_DMA, dmaengine.h header file shouldn't be needed
by netdevice.h anymore.
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Adding support for updating the FW on new port mac, when port mac change
is requested by the user. This info is required by the FW as OEM
management tools require this info directly from the NIC FW.
Check device capability bit to verify the FW supports user mac.
If the FW does support it, use set_port command to notify the FW on the
new mac.
The feature is relevant only to PF port mac.
Signed-off-by: Moshe Shemesh <moshe@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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In order to avoid temporary large structs on the stack,
allocate them dynamically.
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Tal Alon <talal@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We had one call to kmalloc that actually allocates an array. Switch that
one to the kmalloc_array() function.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Some backend devices claim to support write-same,
but would fail actual write-same requests.
Allow to set (or toggle) whether or not DRBD tries to support write-same.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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pci-epc-mem uses a page size equal to *PAGE_SIZE* (usually 4KB) to manage
the address space. However certain platforms like TI's K2G have a
restriction that this address space should be either divided into
1MB/2MB/4MB or 8MB sizes (Ref: 11.14.4.9.1 Outbound Address Translation in
K2G TRM SPRUHY8F January 2016 – Revised May 2017). Add support to handle
different page sizes here.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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In some systems, such as Baseboard Management Controllers (BMCs), we
want to retain the state of LEDs across a reboot of the BMC (whilst the
host remains up). Implement support for the retain-state-shutdown
devicetree property in leds-gpio.
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Acked-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Brandon Wyman <bjwyman@gmail.com>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata
Pull libata fixes from Tejun Heo:
"Late fixes for libata. There's a minor platform driver fix but the
important one is READ LOG PAGE.
This is a new ATA command which is used to test some optional features
but it broke probing of some devices - they locked up instead of
failing the unknown command.
Christoph tried blacklisting, but, after finding out there are
multiple devices which fail this way, backed off to testing feature
bit in IDENTIFY data first, which is a bit lossy (we can miss features
on some devices) but should be a lot safer"
* 'for-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
Revert "libata: quirk read log on no-name M.2 SSD"
libata: check for trusted computing in IDENTIFY DEVICE data
libata: quirk read log on no-name M.2 SSD
sata: ahci-da850: Fix some error handling paths in 'ahci_da850_probe()'
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git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers-next
Kalle Valo says:
====================
wireless-drivers-next patches for 4.14
rsi driver is getting a lot of new features lately, but as usual
active development happening on iwlwifi as well as other drivers.
I pulled wireless-drivers to fix multiple conflicts in iwlwifi and to
make it easier further development.
Major changes:
ath10k
* initial UBS bus support (no full support yet)
* add tdls support for 10.4 firmware
ath9k
* add Dell Wireless 1802
wil6210
* support FW RSSI reporting
rsi
* support legacy power save, U-APSD, rf-kill and AP mode
* RTS threshold configuration
brcmfmac
* support CYW4373 SDIO/USB chipset
iwlwifi
* some more code moved to a new directory
* add new PCI ID for 7265D
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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chip->bits_per_cell which is used to determine the NAND cell type
(SLC/MLC) should always have a value != 0.
Complain loudly if the value is 0 in nand_is_slc() to catch use before
correct initialization.
Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
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This reverts commit 35f0b6a779b8b7a98faefd7c1c660b4dac9a5c26.
We now conditionalize issuing of READ LOG PAGE on the TRUSTED
COMPUTING SUPPORTED bit in the identity data and this shouldn't be
necessary.
Signed-off-by: Tejun Heo <tj@kernel.org>
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ATA-8 and later mirrors the TRUSTED COMPUTING SUPPORTED bit in word 48 of
the IDENTIFY DEVICE data. Check this before issuing a READ LOG PAGE
command to avoid issues with buggy devices. The only downside is that
we can't support Security Send / Receive for a device with an older
revision due to the conflicting use of this field in earlier
specifications.
tj: The reason we need this is because some devices which don't
support READ LOG PAGE lock up after getting issued that command.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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COMPLETION_INITIALIZER_ONSTACK()
In theory, COMPLETION_INITIALIZER_ONSTACK() should never affect the
stack allocation of the caller. However, on some compilers, a temporary
structure was allocated for the return value of
COMPLETION_INITIALIZER_ONSTACK().
For example in write_journal() with LOCKDEP_COMPLETIONS=y (GCC is 7.1.1):
io_comp.comp = COMPLETION_INITIALIZER_ONSTACK(io_comp.comp);
2462: e8 00 00 00 00 callq 2467 <write_journal+0x47>
2467: 48 8d 85 80 fd ff ff lea -0x280(%rbp),%rax
246e: 48 c7 c6 00 00 00 00 mov $0x0,%rsi
2475: 48 c7 c2 00 00 00 00 mov $0x0,%rdx
x->done = 0;
247c: c7 85 90 fd ff ff 00 movl $0x0,-0x270(%rbp)
2483: 00 00 00
init_waitqueue_head(&x->wait);
2486: 48 8d 78 18 lea 0x18(%rax),%rdi
248a: e8 00 00 00 00 callq 248f <write_journal+0x6f>
if (commit_start + commit_sections <= ic->journal_sections) {
248f: 41 8b 87 a8 00 00 00 mov 0xa8(%r15),%eax
io_comp.comp = COMPLETION_INITIALIZER_ONSTACK(io_comp.comp);
2496: 48 8d bd e8 f9 ff ff lea -0x618(%rbp),%rdi
249d: 48 8d b5 90 fd ff ff lea -0x270(%rbp),%rsi
24a4: b9 17 00 00 00 mov $0x17,%ecx
24a9: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi)
if (commit_start + commit_sections <= ic->journal_sections) {
24ac: 41 39 c6 cmp %eax,%r14d
io_comp.comp = COMPLETION_INITIALIZER_ONSTACK(io_comp.comp);
24af: 48 8d bd 90 fd ff ff lea -0x270(%rbp),%rdi
24b6: 48 8d b5 e8 f9 ff ff lea -0x618(%rbp),%rsi
24bd: b9 17 00 00 00 mov $0x17,%ecx
24c2: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi)
We can obviously see the temporary structure allocated, and the compiler
also does two meaningless memcpy with "rep movsq".
And according to:
https://gcc.gnu.org/onlinedocs/gcc/Statement-Exprs.html#Statement-Exprs
The return value of a statement expression is returned by value, so the
temporary variable is created in COMPLETION_INITIALIZER_ONSTACK(), and
that's why the temporary structures are allocted.
To fix this, make the brace block in COMPLETION_INITIALIZER_ONSTACK()
return a pointer and dereference it outside the block rather than return
the whole structure, in this way, we are able to teach the compiler not
to do the unnecessary stack allocation.
This could also reduce the stack size even if !LOCKDEP, for example in
write_journal(), compiled with gcc 7.1.1, the result of command:
objdump -d drivers/md/dm-integrity.o | ./scripts/checkstack.pl x86
before:
0x0000246a write_journal [dm-integrity.o]: 696
after:
0x00002b7a write_journal [dm-integrity.o]: 296
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: walken@google.com
Cc: willy@infradead.org
Link: http://lkml.kernel.org/r/20170823152542.5150-3-boqun.feng@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
struct call_single_data is used in IPIs to transfer information between
CPUs. Its size is bigger than sizeof(unsigned long) and less than
cache line size. Currently it is not allocated with any explicit alignment
requirements. This makes it possible for allocated call_single_data to
cross two cache lines, which results in double the number of the cache lines
that need to be transferred among CPUs.
This can be fixed by requiring call_single_data to be aligned with the
size of call_single_data. Currently the size of call_single_data is the
power of 2. If we add new fields to call_single_data, we may need to
add padding to make sure the size of new definition is the power of 2
as well.
Fortunately, this is enforced by GCC, which will report bad sizes.
To set alignment requirements of call_single_data to the size of
call_single_data, a struct definition and a typedef is used.
To test the effect of the patch, I used the vm-scalability multiple
thread swap test case (swap-w-seq-mt). The test will create multiple
threads and each thread will eat memory until all RAM and part of swap
is used, so that huge number of IPIs are triggered when unmapping
memory. In the test, the throughput of memory writing improves ~5%
compared with misaligned call_single_data, because of faster IPIs.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Huang, Ying <ying.huang@intel.com>
[ Add call_single_data_t and align with size of call_single_data. ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Aaron Lu <aaron.lu@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/87bmnqd6lz.fsf@yhuang-mobile.sh.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
