Since kthread_create can be failed, it needs to check
whether error occurred and return error code.
Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Microsoft LifeCam HD-6000 (045e:076f) requires the similar quirk for
avoiding the stall due to the invalid sample rate reads.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=111491
Signed-off-by: Lev Lybin <lev.lybin@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This reverts commit 14e46e0495.
This ends up doing sysfs operations from deep in balance (where we
should be GFP_NOFS) and under heavy balance load, we're making races
against sysfs internals.
Revert it for now while we figure things out.
Signed-off-by: Chris Mason <clm@fb.com>
Some recent (early 2015) macbooks have Intel Broadwell where LPSS UARTs are
PCI enumerated instead of ACPI. The LPSS UART block is pretty much same as
used on Intel Baytrail so we can reuse the existing Baytrail setup code.
Add both Broadwell LPSS UART ports to the list of supported devices.
Signed-off-by: Leif Liddy <leif.liddy@gmail.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Vbios does this for us on asic_init.
Reviewed-by: Ken Wang >Qingqing.Wang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
In my patch adding native DSD support for the Oppo HA-1, the wrong vendor ID got
through. This patch fixes the vendor ID and aligns the comment.
Fixes: a4eae3a506 ('ALSA: usb: Add native DSD support for Oppo HA-1')
Signed-off-by: Jurgen Kramer <gtmkramer@xs4all.nl>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
There are a couple of nasty truncation bugs lurking in the pageattr
code that can be triggered when mapping EFI regions, e.g. when we pass
a cpa->pgd pointer. Because cpa->numpages is a 32-bit value, shifting
left by PAGE_SHIFT will truncate the resultant address to 32-bits.
Viorel-Cătălin managed to trigger this bug on his Dell machine that
provides a ~5GB EFI region which requires 1236992 pages to be mapped.
When calling populate_pud() the end of the region gets calculated
incorrectly in the following buggy expression,
end = start + (cpa->numpages << PAGE_SHIFT);
And only 188416 pages are mapped. Next, populate_pud() gets invoked
for a second time because of the loop in __change_page_attr_set_clr(),
only this time no pages get mapped because shifting the remaining
number of pages (1048576) by PAGE_SHIFT is zero. At which point the
loop in __change_page_attr_set_clr() spins forever because we fail to
map progress.
Hitting this bug depends very much on the virtual address we pick to
map the large region at and how many pages we map on the initial run
through the loop. This explains why this issue was only recently hit
with the introduction of commit
a5caa209ba ("x86/efi: Fix boot crash by mapping EFI memmap
entries bottom-up at runtime, instead of top-down")
It's interesting to note that safe uses of cpa->numpages do exist in
the pageattr code. If instead of shifting ->numpages we multiply by
PAGE_SIZE, no truncation occurs because PAGE_SIZE is a UL value, and
so the result is unsigned long.
To avoid surprises when users try to convert very large cpa->numpages
values to addresses, change the data type from 'int' to 'unsigned
long', thereby making it suitable for shifting by PAGE_SHIFT without
any type casting.
The alternative would be to make liberal use of casting, but that is
far more likely to cause problems in the future when someone adds more
code and fails to cast properly; this bug was difficult enough to
track down in the first place.
Reported-and-tested-by: Viorel-Cătălin Răpițeanu <rapiteanu.catalin@gmail.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=110131
Link: http://lkml.kernel.org/r/1454067370-10374-1-git-send-email-matt@codeblueprint.co.uk
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
On Broxton, to make sure the reset controller works properly,
MISCBDCGE bit (bit 6) in CGCTL (0x48) of PCI configuration space
need be cleared before reset and set back to 1 after reset.
Otherwise, it may prevent the CORB/RIRB logic from being reset.
Signed-off-by: Libin Yang <libin.yang@linux.intel.com>
Cc: <stable@vger.kernel.org> # v4.4+
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Currently when we boot the kernel on a mx25pdk the LCDC controller
does not show the Linux logo on boot.
This problem is well explained by Sascha Hauer:
"Unfortunately this LCD controller does not have an enable bit. The
controller starts directly when the clocks are enabled. If the clocks
are enabled when the controller is not yet programmed with proper
register values then it just goes into some undefined state. What I
suspect is that the clocks already were enabled before driver probe,
presumably by the bootloader, so the controller is already in undefined
state when entering Linux. Now by dis/enabling the ipg clock you
effectively reset the controller. Since you have programmed it with
valid register values in the mean time it starts working after this
reset."
So do as suggested and force a reset of the LCDC hardware by
enabling and disabling the IPG clock.
With this change the Linux logo can be seen on boot on a mx25pdk.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
ata_sff_hsm_move() triggers BUG if it sees a host state machine state
that it dind't expect. The risk for data corruption when the
condition occurs is low as it's highly unlikely that it would lead to
spurious completion of commands. The BUG occasionally triggered for
subtle race conditions in the driver. Let's downgrade it to WARN so
that it doesn't kill the machine unnecessarily.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
resource_size_t cannot be printed using the %x format string
when we it is defined as u64:
drivers/video/fbdev/mmp/hw/mmp_ctrl.c: In function 'mmphw_probe':
drivers/video/fbdev/mmp/hw/mmp_ctrl.c:506:22: error: format '%x' expects argument of type 'unsigned int', but argument 4 has type 'resource_size_t {aka long long unsigned int}' [-Werror=format=]
dev_err(ctrl->dev, "%s: res %x - %x map failed\n", __func__,
^
drivers/video/fbdev/mmp/hw/mmp_ctrl.c:506:22: error: format '%x' expects argument of type 'unsigned int', but argument 5 has type 'resource_size_t {aka long long unsigned int}' [-Werror=format=]
This changes the format string to %pR, which is interpreted
by the printk implementation to pretty-print a resource
structure.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
The probe function correct passes a dma_addr_t pointer into
dma_alloc_coherent(), but has a cast to resource_size_t, which
might be different from dma_addr_t:
drivers/video/fbdev/da8xx-fb.c: In function 'fb_probe':
drivers/video/fbdev/da8xx-fb.c:1431:10: error: passing argument 3 of 'dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types]
This removes the cast, which avoids the warning.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
The s6e8ax0 suspend/resume functions are hidden inside of an #ifdef
when CONFIG_PM is set to avoid unused function warnings, but they
call some other functions that nothing else calls, and we get warnings
about those:
drivers/video/fbdev/exynos/s6e8ax0.c:449:13: error: 's6e8ax0_sleep_in' defined but not used [-Werror=unused-function]
drivers/video/fbdev/exynos/s6e8ax0.c:485:13: error: 's6e8ax0_display_off' defined but not used [-Werror=unused-function]
This marks the PM functions as __maybe_unused so the compiler can
silently drop them when they are not referenced.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Update the comments around struct iommu_ops to match
current state and fix a few typos while at it.
Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
According to the ocfb documentation:
Fix tgdel HW param should be left margin, not right.
Fix tvdel HW param should upper margin, not lower.
This seems to fix lock issues on certain monitors (tested on a
slightly customized IP, but the FPGA guy said that it should
be the same wrt this changes).
Signed-off-by: Andrea Merello <andrea.merello@gmail.com>
Acked-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Looks like the VT-d spec at intel.com got moved. Update the link.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
In below commit alias DTE is set when its peripheral is
setting DTE. However there's a code bug here to wrongly
set the alias DTE, correct it in this patch.
commit e25bfb56ea
Author: Joerg Roedel <jroedel@suse.de>
Date: Tue Oct 20 17:33:38 2015 +0200
iommu/amd: Set alias DTE in do_attach/do_detach
Signed-off-by: Baoquan He <bhe@redhat.com>
Tested-by: Mark Hounschell <markh@compro.net>
Cc: stable@vger.kernel.org # v4.4
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Trying to build a kernel for ARC with both options CONFIG_COMPILE_TEST
and CONFIG_IOMMU_IO_PGTABLE_LPAE enabled (e.g. as a result of "make
allyesconfig") results in the following build failure:
| CC drivers/iommu/io-pgtable-arm.o
| linux/drivers/iommu/io-pgtable-arm.c: In
| function ‘__arm_lpae_alloc_pages’:
| linux/drivers/iommu/io-pgtable-arm.c:221:3:
| error: implicit declaration of function ‘dma_map_single’
| [-Werror=implicit-function-declaration]
| dma = dma_map_single(dev, pages, size, DMA_TO_DEVICE);
| ^
| linux/drivers/iommu/io-pgtable-arm.c:221:42:
| error: ‘DMA_TO_DEVICE’ undeclared (first use in this function)
| dma = dma_map_single(dev, pages, size, DMA_TO_DEVICE);
| ^
Since IOMMU_IO_PGTABLE_LPAE depends on DMA API, io-pgtable-arm.c should
include linux/dma-mapping.h. This fixes the reported failure.
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Lada Trimasova <ltrimas@synopsys.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This should have happened in 6255c46f (cgroup: rename cgroup
documentations, 2016-01-11).
Signed-off-by: W. Trevor King <wking@tremily.us>
Signed-off-by: Tejun Heo <tj@kernel.org>
omapfb and omapdrm were recently made independent of each other, and
this required Kconfig option changes. This patch changes the
omap2plus_defconfig to enable display similarly as before: omapfb and
panel & encoder drivers as modules.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
The commit cad20c2780 was supposed to
fix handling of devices first using public addresses and then
switching to RPAs after pairing. Unfortunately it missed a couple of
key places in the code.
1. When evaluating which devices should be removed from the existing
white list we also need to consider whether we have an IRK for them or
not, i.e. a call to hci_find_irk_by_addr() is needed.
2. In smp_notify_keys() we should not be requiring the knowledge of
the RPA, but should simply keep the IRK around if the other conditions
require it.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org # 4.4+
At least the l2cap_add_psm() routine depends on the source address
type being properly set to know what auto-allocation ranges to use, so
the assignment to l2cap_chan needs to happen before this.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The LE dynamic PSM range is different from BR/EDR (0x0080 - 0x00ff)
and doesn't have requirements relating to parity, so separate checks
are needed.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Having proper defines makes the code a bit readable, it also avoids
duplicating hard-coded values since these are also needed when
auto-allocating PSM values (in a subsequent patch).
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The I2C bus names are supposed to be stable as they can be used by
userspace to uniquely identify a specific I2C bus. So restore the
original names for all legacy (pre-SB800) devices.
For SB800 devices and later, improve the names. "SDA" refers to the
serial data pin of each SMBus port, it's an implementation detail the
user doesn't need to know. Use "port" instead, which is easier to
understand.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Christian Fetzer <fetzer.ch@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Function nand_setup_cmd_params has 2 goals-
-Initialize the cmd_params field so that it can be used to send and read
commands from the device.
-Get a bus address for the allocated memory to transfer to the device.
Replace the combination of devm_kzalloc and _pa() with dmam_alloc_coherent.
Coherent mapping guarantees that the device and CPU are in sync.
Signed-off-by: Shraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that the perf_event_ctx_lock_nested() call has moved from
put_event() into perf_event_release_kernel() the first reason is no
longer valid as that can no longer happen.
The second reason seems to have been invalidated when Al Viro made fput()
unconditionally async in the following commit:
4a9d4b024a ("switch fput to task_work_add")
such that munmap()->fput()->release()->perf_release() would no longer happen.
Therefore, remove the annotation. This should increase the efficiency
of lockdep coverage of perf locking.
Suggested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The orphan cleanup workqueue doesn't always catch orphans, for example,
if they never schedule after they are orphaned. IOW, the event leak is
still very real. It also wouldn't work for kernel counters.
Doing it synchonously is a little hairy due to lock inversion issues,
but is made to work.
Patch based on work by Alexander Shishkin.
Suggested-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There are two concepts of owner wrt an event and they are conflated:
- event::owner / event::owner_list,
used by prctl(.option = PR_TASK_PERF_EVENTS_{EN,DIS}ABLE).
- the 'owner' of the event object, typically the file descriptor.
Currently these two concepts are conflated, which gives trouble with
scm_rights passing of file descriptors. Passing the event and then
closing the creating task would render the event 'orphan' and would
have it cleared out. Unlikely what is expectd.
This patch untangles these two concepts by using PERF_EVENT_STATE_EXIT
to denote the second type.
Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In preparation to adding more options, convert the boolean argument
into a flags word.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
sync_child_event() has outgrown its purpose, it does far too much.
Bring it back to its named purpose.
Rename __perf_event_exit_task() to perf_event_exit_event() to better
reflect what it does and move the event->state assignment under the
ctx->lock, like state changes ought to be.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use smp_store_release() to clear event->owner and
lockless_dereference() to observe it. Further use READ_ONCE() for all
lockless reads.
This changes perf_remove_from_owner() to leave event->owner cleared.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We should never attempt to enable a STATE_EXIT event.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
There is but a single caller, remove the function - we already have
_free_event(), the extra indirection is nonsensical..
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When calling intel_alt_er() with .idx != EXTRA_REG_RSP_* we will not
initialize alt_idx and then use this uninitialized value to index an
array.
When that is not fatal, it can result in an infinite loop in its
caller __intel_shared_reg_get_constraints(), with IRQs disabled.
Alternative error modes are random memory corruption due to the
cpuc->shared_regs->regs[] array overrun, which manifest in either
get_constraints or put_constraints doing weird stuff.
Only took 6 hours of painful debugging to find this. Neither GCC nor
Smatch warnings flagged this bug.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: ae3f011fc2 ("perf/x86/intel: Fix SLM MSR_OFFCORE_RSP1 valid_mask")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add ACPI binding to the android pipe driver
Signed-off-by: Jason Hu <jia-cheng.hu@intel.com>
Signed-off-by: Jin Qian <jinqian@android.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For reading and writing guest user space buffers, currently the kernel
sends the guest virtual address of the buffer to the pipe device. This
virtual address has to be first converted to a guest physical address.
Doing this translation on the QEMU side is inefficient and requires
additional handling when KVM is enabled, whose implementation would
either incur intrusive changes to QEMU's KVM support code or suffer
from poor performance, see commit 08c7228c50f8 ("x86-kvm: only sync
SREGS when doing address translation") of $AOSP/external/qemu for
details, and thus should be avoided if possible.
There is a TODO comment in hw/misc/android_pipe.c in the new Android
emulator source tree ($AOSP/external/qemu-android) which requests that
the translation be done on the kernel side and that physical addresses
be passed to the device instead of virtual ones. Once the QEMU-side
implementation is done, the kernel will need to support both the new
paddr-based pipe device and the old vaddr-based one (which will
continue to be used by the classic emulator). This patch achieves that
by leveraging the device version register available in the new device.
See https://android-review.googlesource.com/128280 for the QEMU-side
patch.
In addition, use the mmap semaphore (in read mode) to safeguard the
call to get_user_pages().
Signed-off-by: Yu Ning <yu.ning@intel.com>
Signed-off-by: Jin Qian <jinqian@android.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On PIPE_ERROR_AGAIN, just stopping in the middle of a transfer and
returning the number of bytes actually handled is the right behavior.
Other errors should be returned on the next read() or write() call.
Continue logging those until we confirm nothing actually relies on the
existing (wrong) behavior of dropping errors on the floor.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Jin Qian <jinqian@android.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add bindings so we don't need to rely on goldfish virtual bus for
probing any more, which means we don't need ARM and MIPS goldfish
board code for instantiating the bus.
In the long term we would like to move towards replacing the Android
pipe with virtio-vsock that is currently under development.
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Jin Qian <jinqian@android.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
