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: Christoffer Dall <christoffer.dall@linaro.org>
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>
It just makes it harder to figure out which commands are being used.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
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>
Here's the big, really big, staging tree patches for 4.2-rc1.
Loads of stuff in here, almost all just coding style fixes / churn, and
a few new drivers as well, one of which I just disabled from the build a
few minutes ago due to way too many build warnings.
Other than the one "disable this driver" patch, all of these have been
in linux-next for quite a while with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
iEYEABECAAYFAlWNpc0ACgkQMUfUDdst+ym8EgCg0pL1Qcf9Se3jAc96fLt+itpv
Rd0AoI9uJcq8Qm7d+IXnz3ojLnN9xvN3
=xt0u
-----END PGP SIGNATURE-----
Merge tag 'staging-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver updates from Greg KH:
"Here's the big, really big, staging tree patches for 4.2-rc1.
Loads of stuff in here, almost all just coding style fixes / churn,
and a few new drivers as well, one of which I just disabled from the
build a few minutes ago due to way too many build warnings.
Other than the one "disable this driver" patch, all of these have been
in linux-next for quite a while with no reported issues"
* tag 'staging-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1163 commits)
staging: wilc1000: disable driver due to build warnings
Staging: rts5208: fix CHANGE_LINK_STATE value
Staging: sm750fb: ddk750_swi2c.c: Insert spaces before parenthesis
Staging: sm750fb: ddk750_swi2c.c: Place braces on correct lines
Staging: sm750fb: ddk750_swi2c.c: Insert spaces around operators
Staging: sm750fb: ddk750_swi2c.c: Replace spaces with tabs
Staging: sm750fb: ddk750_swi2c.h: Shorten lines to under 80 characters
Staging: sm750fb: ddk750_swi2c.h: Replace spaces with tabs
Staging: sm750fb: modedb.h: Shorten lines to under 80 characters
Staging: sm750fb: modedb.h: Replace spaces with tabs
staging: comedi: addi_apci_3120: rename 'this_board' variables
staging: comedi: addi_apci_1516: rename 'this_board' variables
staging: comedi: ni_atmio: cleanup ni_getboardtype()
staging: comedi: vmk80xx: sanity check context used to get the boardinfo
staging: comedi: vmk80xx: rename 'boardinfo' variables
staging: comedi: dt3000: rename 'this_board' variables
staging: comedi: adv_pci_dio: rename 'this_board' variables
staging: comedi: cb_pcidas64: rename 'thisboard' variables
staging: comedi: cb_pcidas: rename 'thisboard' variables
staging: comedi: me4000: rename 'thisboard' variables
...
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: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: Greg 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: Fengguang Wu <fengguang.wu@intel.com>
Cc: Jun Tian <jun.j.tian@intel.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Greg 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: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg 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: Jun Tian <jun.j.tian@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Support 64-bit channel and address for the goldfish pipe driver.
Signed-off-by: Jun Tian <jun.j.tian@intel.com>
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Brian Wood <brian.j.wood@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Note a point in the pipe driver that wants future attention
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg 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: David 'Digit' Turner <digit@android.com>
[Added support for parameter buffers for speed]
igned-off-by: Xin, Xiaohui <xiaohui.xin@intel.com>
Signed-off-by: Jiang, Yunhong <yunhong.jiang@intel.com>
Signed-off-by: Nakajima, Jun <jun.nakajima@intel.com>
[Ported to 3.6]
Signed-off-by: Tom Keel <thomas.keel@intel.com>
[Ported to 3.7, moved to platform/goldfish]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
