This removes the 'write' and 'force' from get_user_pages() and replaces
them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers
as use of this flag can result in surprising behaviour (and hence bugs)
within the mm subsystem.
Signed-off-by: NLorenzo Stoakes <lstoakes@gmail.com>
Acked-by: NChristian König <christian.koenig@amd.com>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit d4edcf0d ("mm/gup: Switch all callers of get_user_pages() to
not pass tsk/mm") switched get_user_pages() callers to the simpler model
where they no longer pass in the thread and mm pointer.  But since then
we've merged changes to a few drivers that re-introduce use of the old
interface.  Let's fix them up.

They continued to work fine (thanks to the truly disgusting macros
introduced in commit cde70140: "mm/gup: Overload get_user_pages()
functions"), but cause unnecessary build noise.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Coherent mapping guarantees that the device and CPU are in sync.
Signed-off-by: NShraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We recently messed up the error handling here.  We can return with the
pipe->lock held or sometimes we unlock twice by mistake.

Fixes: 2f3be882 ('goldfish_pipe: Pin pages to memory while copying and other cleanups')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add ACPI binding to the android pipe driver
Signed-off-by: NJason Hu <jia-cheng.hu@intel.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg 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: NYu Ning <yu.ning@intel.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg 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: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg 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: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Acked-by: NRob Herring <robh@kernel.org>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The existing code had a troubling TODO statement concerning the fact
that it just did a check if the page that the QEMU backend was going to
read from / write to was there before the call to the QEMU backend and
then relying on the fact that the page stayed around, even in a
preemptible SMP kernel.  Obviously the page could go away or be
reassigned, and strange things may happen.

Further, writes were not tracked, so any use of COW or KSM-like
features would break completely.  Probably that was never used by adbd
(the only current active user of the pipe), but could prove much more
dangerous for the GPU passthrough mechanism.

Instead, use get_user_pages() as the comment suggested and cleanup the
error path and add the set_page_dirt() call on a successful read
operation.

Also clarify the count used to return from successful read/write calls
and use Linux style commentary in various places of the file.

Note: The "just ignore error and return whatever we read so far" error
handling is really quite horrific.  I cannot change it without a more
careful study of all user space ABIs reliance on this 'feature'.
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It just makes it harder to figure out which commands are being used.
Signed-off-by: NAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As the first argument of gf_write64() was of type unsigned long, and as
some calls to gf_write64() were casting the first argument from void *
to u64 the compiler and/or sparse were printing warnings for casts of
wrong sizes when compiling for i386.

This patch changes the type of the first argument of gf_write64() to
const void *, and update calls to the function. This change fixed the
warnings and allowed to remove casts from 3 calls to gf_write64().

In addition gf_write64() was renamed to gf_write_ptr() as the name was
misleading because it only writes 32 bits on 32 bit systems.

gf_write_dma_addr() was added to handle dma_addr_t values which is
used at drivers/staging/goldfish/goldfish_audio.c.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move the close parenthesis.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/platform/goldfish/goldfish_pipe.c: In function 'goldfish_cmd_status':
drivers/platform/goldfish/goldfish_pipe.c:164:14: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
     writel((u32)(u64)pipe, dev->base + PIPE_REG_CHANNEL);
                 ^
drivers/platform/goldfish/goldfish_pipe.c: In function 'goldfish_cmd':
drivers/platform/goldfish/goldfish_pipe.c:180:14: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
     writel((u32)(u64)pipe, dev->base + PIPE_REG_CHANNEL);
                 ^
drivers/platform/goldfish/goldfish_pipe.c: In function 'goldfish_pipe_read_write':
drivers/platform/goldfish/goldfish_pipe.c:337:16: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
       writel((u32)(u64)pipe, dev->base + PIPE_REG_CHANNEL);
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Cc: Jun Tian <jun.j.tian@intel.com>
Acked-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NOctavian Purdila <octavian.purdila@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the 64bit helper method to scrub most of the ifdefs from the driver. The
pipe reading has a funny case we can't scrub completely.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When using multiple adb on 64 bit kernel to transfer data,
the goldfish pipe interrupt will crash the kernel.
Signed-off-by: NJun Tian <jun.j.tian@intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Support 64-bit channel and address for the goldfish pipe driver.
Signed-off-by: NJun Tian <jun.j.tian@intel.com>
Signed-off-by: NOctavian Purdila <octavian.purdila@intel.com>
Signed-off-by: NBrian Wood <brian.j.wood@intel.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Note a point in the pipe driver that wants future attention
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

A QEMU pipe is a very fast communication channel between the
guest system and the emulator. Usage from the guest is simply
something like;

  // connect to special device
  fd = open("/dev/qemu_pipe", O_RDWR);

  // tell which service we want to talk to (must be zero-terminated)
  write(fd, "pipeName", strlen("pipeName")+1);

  // do read()/write() through fd now
  ...

  // close channel
  close(fd);
Signed-off-by: NDavid 'Digit' Turner <digit@android.com>
[Added support for parameter buffers for speed]
igned-off-by: NXin, Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: NJiang, Yunhong <yunhong.jiang@intel.com>
Signed-off-by: NNakajima, Jun <jun.nakajima@intel.com>
[Ported to 3.6]
Signed-off-by: NTom Keel <thomas.keel@intel.com>
[Ported to 3.7, moved to platform/goldfish]
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>