Commit Graph
100 Commits
Author SHA1 Message Date
Colin Cross abcc61537e ANDROID: binder: Add BINDER_GET_NODE_DEBUG_INFO ioctl
The BINDER_GET_NODE_DEBUG_INFO ioctl will return debug info on
a node.  Each successive call reusing the previous return value
will return the next node.  The data will be used by
libmemunreachable to mark the pointers with kernel references
as reachable.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Martijn Coenen <maco@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-01 09:21:12 +02:00
Colin Cross cc635da2e2 staging: lowmemorykiller: Make default lowmemorykiller debug message useful
lowmemorykiller debug messages are inscrutable and mostly useful
for debugging the lowmemorykiller, not explaining why a process
was killed.  Make the messages more useful by prefixing them
with "lowmemorykiller: " and explaining in more readable terms
what was killed, who it was killed for, and why it was killed.

The messages now look like:
[   76.997631] lowmemorykiller: Killing 'droid.gallery3d' (2172), adj 1000,
[   76.997635]    to free 27436kB on behalf of 'kswapd0' (29) because
[   76.997638]    cache 122624kB is below limit 122880kB for oom_score_adj 1000
[   76.997641]    Free memory is -53356kB above reserved

A negative number for free memory above reserved means some of the
reserved memory has been used and is being regenerated by kswapd,
which is likely what called the shrinkers.

Cc: Android Kernel Team <kernel-team@android.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: Minor checkpatch tweaks]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 17:34:58 -08:00
Colin Cross 382c55f88f mmc: block: Allow more than 8 partitions per card
It is quite common for Android devices to utilize more
then 8 partitions on internal eMMC storage.

The vanilla kernel can support this via
CONFIG_MMC_BLOCK_MINORS, however that solution caps the
system to 256 minors total, which limits the number of
mmc cards the system can support.

This patch, which has been carried for quite awhile in
the AOSP common tree, provides an alternative solution
that doesn't seem to limit the total card count. So I
wanted to submit it for consideration upstream.

This patch sets the GENHD_FL_EXT_DEVT flag, which will
allocate minor number in major 259 for partitions past
disk->minors.

It also removes the use of disk_devt to determine devidx
from md->disk. md->disk->first_minor is always initialized
from devidx and can always be used to recover it.

Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Chuanxiao Dong <chuanxiao.dong@intel.com>
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Austin S Hemmelgarn <ahferroin7@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Android Kernel Team <kernel-team@android.com>
Cc: linux-mmc@vger.kernel.org
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: Added context to commit message]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
2015-12-28 12:51:38 +01:00
Colin Cross dc3814f404 iommu/exynos: Tell kmemleak to ignore 2nd level page tables
The pointers to the 2nd level page tables are converted to 1st level
page table entries, which means kmemleak can't find them and assumes
they have been leaked.  Call kmemleak_ignore on the 2nd level page
tables to prevent them from showing up in kmemleak reports.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2015-05-11 18:47:52 +02:00
Colin Cross 5516fd7b92 debug: prevent entering debug mode on panic/exception.
On non-developer devices, kgdb prevents the device from rebooting
after a panic.

Incase of panics and exceptions, to allow the device to reboot, prevent
entering debug mode to avoid getting stuck waiting for the user to
interact with debugger.

To avoid entering the debugger on panic/exception without any extra
configuration, panic_timeout is being used which can be set via
/proc/sys/kernel/panic at run time and CONFIG_PANIC_TIMEOUT sets the
default value.

Setting panic_timeout indicates that the user requested machine to
perform unattended reboot after panic. We dont want to get stuck waiting
for the user input incase of panic.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
Cc: Android Kernel Team <kernel-team@android.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Colin Cross <ccross@android.com>
[Kiran: Added context to commit message.
panic_timeout is used instead of break_on_panic and
break_on_exception to honor CONFIG_PANIC_TIMEOUT
Modified the commit as per community feedback]
Signed-off-by: Kiran Raparthy <kiran.kumar@linaro.org>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2015-02-19 12:39:03 -06:00
Colin Cross fa2ec3ea10 arm64: implement TASK_SIZE_OF
include/linux/sched.h implements TASK_SIZE_OF as TASK_SIZE if it
is not set by the architecture headers.  TASK_SIZE uses the
current task to determine the size of the virtual address space.
On a 64-bit kernel this will cause reading /proc/pid/pagemap of a
64-bit process from a 32-bit process to return EOF when it reads
past 0xffffffff.

Implement TASK_SIZE_OF exactly the same as TASK_SIZE with
test_tsk_thread_flag instead of test_thread_flag.

Cc: stable@vger.kernel.org
Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-08 17:30:59 +01:00
Colin Cross b9daf0b60b staging: ion: Move shrinker out of heaps
Every heap that uses deferred frees is going to need a shrinker
to shrink the freelist under memory pressure.  Rather than
requiring each heap to implement a shrinker, automatically
register a shrinker if the deferred free flag is set.
The system heap also needs to shrink its page pools, so add
a shrink function to the heap ops that will be called after
shrinking the freelists.

Cc: Colin Cross <ccross@android.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: Resolved big conflicts with the shrinker api change.
Also minor commit subject tweak.]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-18 11:05:08 -08:00
Colin Cross a3e9ddb77e staging: android: Split uapi out of binder.h
Move the userspace interface of binder.h to
drivers/staging/android/uapi/binder.h.

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Colin Cross <ccross@android.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: Worked out the collisions from some of the type changes
made upstream. Also minor commit subject tweak]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-18 11:03:28 -08:00
Colin Cross 64907b94da staging: android: split uapi out of sync.h and sw_sync.h
Move the userspace interfaces of sync.h and sw_sync.h to
drivers/staging/android/uapi/

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Colin Cross <ccross@android.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: Fixed up some conflicts from upstream spelling fixes]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-18 11:03:28 -08:00
Colin Cross fe8a78e4ba staging: android: Split uapi out of ashmem.h
Move the userspace interface of ashmem.h to
drivers/staging/android/uapi/ashmem.h

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Colin Cross <ccross@android.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: Minor commit message tweak]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-18 11:03:28 -08:00
Colin Cross a6b0961963 staging: android: Split uapi out of android_alarm.h
Move the userspace interface of android_alarm.h to
drivers/staging/android/uapi/android_alarm.h

Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Colin Cross <ccross@android.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: minor commit msg tweak]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-18 11:03:28 -08:00
Colin Cross fee0c54e28 dma-buf: avoid using IS_ERR_OR_NULL
dma_buf_map_attachment and dma_buf_vmap can return NULL or
ERR_PTR on a error.  This encourages a common buggy pattern in
callers:
	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
	if (IS_ERR_OR_NULL(sgt))
                return PTR_ERR(sgt);

This causes the caller to return 0 on an error.  IS_ERR_OR_NULL
is almost always a sign of poorly-defined error handling.

This patch converts dma_buf_map_attachment to always return
ERR_PTR, and fixes the callers that incorrectly handled NULL.
There are a few more callers that were not checking for NULL
at all, which would have dereferenced a NULL pointer later.
There are also a few more callers that correctly handled NULL
and ERR_PTR differently, I left those alone but they could also
be modified to delete the NULL check.

This patch also converts dma_buf_vmap to always return NULL.
All the callers to dma_buf_vmap only check for NULL, and would
have dereferenced an ERR_PTR and panic'd if one was ever
returned. This is not consistent with the rest of the dma buf
APIs, but matches the expectations of all of the callers.

Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07 14:21:09 -08:00
Colin Cross c9e8440eca staging: ion: Fix overflow and list bugs in system heap
Fix a few bugs in ion_system_heap:

Initialize the list node in the info block.

Don't store size_remaining in a signed long, allocating >2GB
could overflow, resulting in a call to sg_alloc_table with
nents=0 which panics.  alloc_largest_available will never
return a block larger than size_remanining, so it can never
go negative.

Limit a single allocation to half of all memory.  Prevents a
large allocation from taking down the whole system.

Cc: Colin Cross <ccross@android.com>
Cc: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: Minor commit subject tweak]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07 09:03:16 -08:00
Colin Cross 530b099dfe security: select correct default LSM_MMAP_MIN_ADDR on arm on arm64
Binaries compiled for arm may run on arm64 if CONFIG_COMPAT is
selected.  Set LSM_MMAP_MIN_ADDR to 32768 if ARM64 && COMPAT to
prevent selinux failures launching 32-bit static executables that
are mapped at 0x8000.

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-02-05 14:59:14 +00:00
Colin Cross 0462e185ca ion: remove ion_user_handle_t from ion_test.h
ion_test.h should not define ion_user_handle_t, and defining it
causes a warning:
In file included from drivers/staging/android/ion/ion_test.c:31:
drivers/staging/android/ion/../uapi/ion_test.h:23: error: redefinition of typedef 'ion_user_handle_t'
drivers/staging/android/ion/../uapi/ion.h:23: note: previous declaration of 'ion_user_handle_t' was here

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-16 17:18:22 -08:00
Colin Cross 661f82f6c2 ion: fix bugs in cma heap
Implement ion_cma_unmap_kernel, ion will call it unconditionally.
Use correct gfp flags when calling dma_alloc_coherent so it doesn't
try to use atomic DMA memory.
Check for invalid alignment when allocating.
Reject cached allocations - the cpu address returned by
dma_alloc_coherent is always going to be an uncached mapping, so
map_kernel will not see data written by a cached userspace mapping.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:54 -08:00
Colin Cross dd608dd29a ion: add alignment check to chunk heap
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:54 -08:00
Colin Cross df6cf5c8af ion: add helper to zero contiguous region of pages
Add ion_heap_pages_zero for ion heaps to use to zero pages
during initialization or allocation, when a struct ion_buffer
may not be available.  Use it from the chunk heap and carveout
heaps.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:54 -08:00
Colin Cross ed5bf01aac ion: carveout heap: zero buffers on free, fix memory leak
The carveout heap wasn't zeroing its buffers after use.
Create the sg_table during allocate instead of map_dma, to allow
using the sg_table during free, and call ion_heap_buffer_zero
during free.  Also fixes a missing kfree when destroying the
table.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:54 -08:00
Colin Cross f63958d80c ion: fix sparse warnings
Fix sparse warnings in ion.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:54 -08:00
Colin Cross 5c6a470557 ion: use alloc_pages in system contig heap
There is no reason to use kzalloc, just call alloc_pages directly.
Change the GFP from GFP_KERNEL to include __GFP_HIGH, to allow it
to return contiguous pages from highmem.  virt_to_* functions
aren't valid on highmem pages, so store the struct page * in an
sg_table in buffer->priv_virt like most other heaps, and replace
virt_to_* with page_to_*.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:53 -08:00
Colin Cross a053b6ace1 ion: allow cached mappings of chunk and system heap buffers
Now that ion_vm_fault uses vm_insert_pfn instead of vm_insert_page
cached buffers can be supported in any heap.  Remove the checks
in the chunk and system heaps.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:53 -08:00
Colin Cross a3056906bf ion: remove ion_heap_alloc_pages
Now that ion_vm_fault doesn't need a struct page with a nonzero
refcount, there is no need allocate heap memory for cached pages using
split_page.  Remove the ion_heap_alloc_pages and ion_heap_free_pages
helpers in favor of direct calls to alloc_pages and __free_pages,
and remove the special handling in the system heap.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:53 -08:00
Colin Cross 462be0c616 ion: use vm_insert_pfn for faulted pages
Most ion userspace mappings are created with remap_pfn_range.  Use
vm_insert_pfn instead of vm_insert_page to make faulted cached
mappings look more like uncached mappings.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:53 -08:00
Colin Cross e460bc5e43 ion: check return value from remap_pfn_range
Check the return value of remap_pfn_range and return an error if
it fails.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:53 -08:00
Colin Cross ce3d10933a ion: free low memory from page pools first
When the shrinkers are called with GFP_HIGH free low memory first,
it is more important to have free than high memory.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:53 -08:00
Colin Cross 8b312bb9a7 ion: optimize ion_heap_buffer_zero
ion_heap_buffer_zero can spend a long time in unmap_kernel_range
if it has to broadcast a tlb flush to every cpu for every page.
Modify it to batch pages into a larger region to clear using a
single mapping.  This may cause the mapping size to change if
the buffer size is not a multiple of the mapping size, so
switch to allocating the address space for each chunk.  This
allows us to use vm_map_ram to handle the allocation and mapping
together.

The number of pages to zero using a single mapping is set to 32
to hit the fastpath in vm_map_ram.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:53 -08:00
Colin Cross f0f0676382 ion: add alignment check to carveout heap
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:53 -08:00
Colin Cross 797e88be2f ion: drop dependency on ARM
Ion will compile and run on other platforms now, remove the
dependency on ARM.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:59:53 -08:00
Colin Cross db866e3ded ion: clean up ioctls
Convert the ion ioctls to use _IOW instead of _IOWR where
appropriate, and factor out the copy_from_user and copy_to_user
based on the _IOC_DIR bits.  For the existing incorrect ioctls,
add a function to wrap _IOC_DIR to return the corrected value.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:19 -08:00
Colin Cross a82130f470 gpu: ion: remove unnecessary function from system heap
ion_system_contig_heap buffers have an sglist, just call
ion_heap_map_user to map it.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:19 -08:00
Colin Cross e61fc915fa ion: fix printk warnings
Use %z for size_t and %pa for dma_addr_t to avoid warnings in printks.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:19 -08:00
Colin Cross 1d804535c3 ion: don't use phys_to_page or __phys_to_pfn
phys_to_page and __phys_to_pfn don't exist on all platforms.
Use a combination of pfn_to_page, PFN_DOWN, page_to_pfn, and
virt_to_page to get the same results.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:19 -08:00
Colin Cross 8be3759a5e ion: don't use __arm_ioremap to map pages
ion_heap_map_kernel already implements mapping a scatterlist of
pages into the kernel, and all heaps are required to have struct
pages associated with them, so delete the functions that use
__arm_ioremap and use ion_heap_map_kernel instead.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:19 -08:00
Colin Cross b26661d1f6 ion: update idr to avoid deprecated apis
Use idr_alloc instead if idr_pre_get/idr_get_new_above, and
remove idr_remove_all.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:19 -08:00
Colin Cross ceff95d49c ion: add test device for unit tests to interact with dma_bufs
Add a /dev/ion-test device that will be created if CONFIG_ION_TEST
is set.  The device accepts a dma_buf fd and allows reading and
writing to the backing memory using DMA-like apis or kernel mapping
apis.  Can be used to test the dma_buf mapping ops, including
the ion implementations, from userspace.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:19 -08:00
Colin Cross c13d1df947 ion: check invalid values in ion_system_heap
ion_system_heap can only satisfy page alignment, and
ion_system_contig_heap can only satisify alignment to the
allocation size.  Neither can support faulting user mappings
because they use slab pages.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:19 -08:00
Colin Cross 06e0dcaeb4 ion: convert sg_dma_len(sg) to sg->length
ion is always dealing with the allocation and not the mapping,
so it should always be using sg->length and not sg->dma_length.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:18 -08:00
Colin Cross e946b209c2 ion: fix dma APIs
__dma_page_cpu_to_dev is a private ARM api that is not available
on 3.10 and was never available on other architectures.  We can
get the same behavior by calling dma_sync_sg_for_device with a
scatterlist containing a single page.  It's still not quite a
kosher use of the dma apis, we still conflate physical addresses
with bus addresses, but it should at least compile on all
platforms, and work on any platform that doesn't have a physical
to bus address translation.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:18 -08:00
Colin Cross a14baf71b9 ion: fix crash when alloc len is -1
If userspace passes a length between -4095 and -1 to allocate it
will pass the len != 0 check, but when len is page aligned it will
be 0.  Check len after page aligning.

Drop the warning as well, userspace shouldn't be able to trigger
a warning in the kernel.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:18 -08:00
Colin Cross 83271f6262 ion: hold reference to handle after ion_uhandle_get
commit 1262ab1846cf76f7549c66ef709120dbfbe6d49f (ion: replace
userspace handle cookies with idr) broke the locking in ion.
The ION_IOC_FREE and ION_IOC_MAP ioctls were relying on
ion_handle_validate to detect the case where a call raced
with another ION_IOC_FREE which may have freed the struct
ion_handle.

Rename ion_uhandle_get to ion_handle_get_by_id, and have it
take the client lock and return with an extra reference to
the handle.  Make each caller put its reference once it
is done with the handle.

Also modify users of ion_handle_validate to continue to hold
the client lock after calling ion_handle_validate until
they are done with the handle, and warn if ion_handle_validate
is called without the client lock held.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:18 -08:00
Colin Cross c3a2fe0314 ion: move userspace api into uapi/ion.h
Split the userspace api out of drivers/staging/android/ion/ion.h
into drivers/staging/android/uapi/ion.h

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:18 -08:00
Colin Cross 9e57e108d2 gpu: ion: delete ion_system_mapper.c
The mapper abstraction layer was removed before the initial ion
commit, but a stray ion_system_mapper.c file was left in.  Delete
it.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:18 -08:00
Colin Cross b4f8d242c6 ion: don't use id 0 for handle cookie
ion userspace clients think that the cookie is a pointer, so they
use NULL to check if the handle has been initialized.  Set the first
id number to 1.

Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:18 -08:00
Colin Cross e1cf368234 ion: index client->handles rbtree by buffer
The only remaining users of the client->handles rbtree are
iterating through it like a list.  Keep the rbtree, but change
its index to be the buffer address instead of the handle address,
which makes ion_handle_lookup a fast rbtree search.

Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:18 -08:00
Colin Cross 47b404580b ion: replace userspace handle cookies with idr
Userspace handles should not leak kernel virtual addresses to
userspace.  They have to be validated by looking them up in an
rbtree anyways, so replace them with an idr and validate them
by using idr_find to convert the id number to the struct
ion_handle pointer.

Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:18 -08:00
Colin Cross 9e907654d3 ion: remove IS_ERR_OR_NULL
IS_ERR_OR_NULL is often part of a bad pattern that can accidentally
return 0 on error:
if (IS_ERR_OR_NULL(ptr))
    return PTR_ERR(ptr);

It also usually means that the errors of a function are not well
defined.  Replace all uses in ion.c by ensure that the return
type of any function in ion is an ERR_PTR.

Specify that the expected return value from map_kernel or map_dma
heap ops is ERR_PTR, and warn if a heap returns NULL.

Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:17 -08:00
Colin Cross dfc4a9b176 ion: convert map_kernel to return ERR_PTR
ion is going to stop accepting NULL as an error value, use ERR_PTR.

Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:17 -08:00
Colin Cross 2540c73a5b ion: add free list size to heap debug files
Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:17 -08:00
Colin Cross ea89faff84 ion: chunk_heap: fix leak in allocated counter
buffer->size is controlled by the outer ion layer, don't modify it
inside the heap.  Instead, compute the rounded up allocated size
on demand.

Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:57:17 -08:00
Colin Cross 0f3cbb59ec gpu: ion: ion_carveout_heap: fix for 3.4
__arch_ioremap is no longer available, use __arm_ioremap instead.

Signed-off-by: Colin Cross <ccross@android.com>
[jstultz: modified patch to apply to staging directory]
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-14 08:55:36 -08:00
Colin Cross 9e19b73c30 cpuidle: coupled: fix race condition between pokes and safe state
The coupled cpuidle waiting loop clears pending pokes before
entering the safe state.  If a poke arrives just before the
pokes are cleared, but after the while loop condition checks,
the poke will be lost and the cpu will stay in the safe state
until another interrupt arrives.  This may cause the cpu that
sent the poke to spin in the ready loop with interrupts off
until another cpu receives an interrupt, and if no other cpus
have interrupts routed to them it can spin forever.

Change the return value of cpuidle_coupled_clear_pokes to
return if a poke was cleared, and move the need_resched()
checks into the callers.  In the waiting loop, if
a poke was cleared restart the loop to repeat the while
condition checks.

Reported-by: Neil Zhang <zhangwm@marvell.com>
Signed-off-by: Colin Cross <ccross@android.com>
Cc: 3.6+ <stable@vger.kernel.org> # 3.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-29 22:15:34 +02:00
Colin Cross f983827bcb cpuidle: coupled: abort idle if pokes are pending
Joseph Lo <josephl@nvidia.com> reported a lockup on Tegra20 caused
by a race condition in coupled cpuidle.  When two or more cpus
enter idle at the same time, the first cpus to arrive may go to the
ready loop without processing pending pokes from the last cpu to
arrive.

This patch adds a check for pending pokes once all cpus have been
synchronized in the ready loop and resets the coupled state and
retries if any cpus failed to handle their pending poke.

Retrying on all cpus may trigger the same issue again, so this patch
also adds a check to ensure that each cpu has received at least one
poke between when it enters the waiting loop and when it moves on to
the ready loop.

Reported-and-tested-by: Joseph Lo <josephl@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Colin Cross <ccross@android.com>
Cc: 3.6+ <stable@vger.kernel.org> # 3.6+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-29 22:15:04 +02:00
Colin Cross 59e9985611 cpuidle: coupled: disable interrupts after entering safe state
Calling cpuidle_enter_state is expected to return with interrupts
enabled, but interrupts must be disabled before starting the
ready loop synchronization stage.  Call local_irq_disable after
each call to cpuidle_enter_state for the safe state.

Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-29 22:11:38 +02:00
Colin Cross 2b44c4db2e freezer: set PF_SUSPEND_TASK flag on tasks that call freeze_processes
Calling freeze_processes sets a global flag that will cause any
process that calls try_to_freeze to enter the refrigerator.  It
skips sending a signal to the current task, but if the current
task ever hits try_to_freeze, all threads will be frozen and the
system will deadlock.

Set a new flag, PF_SUSPEND_TASK, on the task that calls
freeze_processes.  The flag notifies the freezer that the thread
is involved in suspend and should not be frozen.  Also add a
WARN_ON in thaw_processes if the caller does not have the
PF_SUSPEND_TASK flag set to catch if a different task calls
thaw_processes than the one that called freeze_processes, leaving
a task with PF_SUSPEND_TASK permanently set on it.

Threads that spawn off a task with PF_SUSPEND_TASK set (which
swsusp does) will also have PF_SUSPEND_TASK set, preventing them
from freezing while they are helping with suspend, but they need
to be dead by the time suspend is triggered, otherwise they may
run when userspace is expected to be frozen.  Add a WARN_ON in
thaw_processes if more than one thread has the PF_SUSPEND_TASK
flag set.

Reported-and-tested-by: Michael Leun <lkml20130126@newton.leun.net>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-30 14:05:06 +02:00
Colin Cross 88c8004fd3 futex: Use freezable blocking call
Avoid waking up every thread sleeping in a futex_wait call during
suspend and resume by calling a freezable blocking call.  Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Signed-off-by: Colin Cross <ccross@android.com>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: arve@android.com
Cc: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Link: http://lkml.kernel.org/r/1367458508-9133-8-git-send-email-ccross@android.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-06-25 23:11:19 +02:00
Colin Cross 5c83545f24 power: Add option to log time spent in suspend
Below is a patch from android kernel that maintains a histogram of
suspend times. Please review and provide feedback.

Statistices on the time spent in suspend are kept in
/sys/kernel/debug/sleep_time.

Cc: Android Kernel Team <kernel-team@android.com>
Cc: Colin Cross <ccross@android.com>
Cc: Todd Poynor <toddpoynor@google.com>
Cc: San Mehat <san@google.com>
Cc: Benoit Goby <benoit@android.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
[zoran.markovic@linaro.org: Re-formatted suspend time table to better
fit expected values. Moved accounting of suspend time into timekeeping
core. Removed CONFIG_SUSPEND_TIME flag and made the feature conditional
on CONFIG_DEBUG_FS. Changed the file name to sleep_time to better fit
terminology in timekeeping core. Changed seq_printf to seq_puts. Tweaked
commit message]
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-05-29 12:57:34 -07:00
Colin Cross 2b15af6f95 af_unix: use freezable blocking calls in read
Avoid waking up every thread sleeping in read call on an AF_UNIX
socket during suspend and resume by calling a freezable blocking
call.  Previous patches modified the freezer to avoid sending
wakeups to threads that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:23 +02:00
Colin Cross a2d5f1f5d9 sigtimedwait: use freezable blocking call
Avoid waking up every thread sleeping in a sigtimedwait call during
suspend and resume by calling a freezable blocking call.  Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:23 +02:00
Colin Cross b0f8c44f30 nanosleep: use freezable blocking call
Avoid waking up every thread sleeping in a nanosleep call during
suspend and resume by calling a freezable blocking call.  Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:23 +02:00
Colin Cross 56467c7697 futex: use freezable blocking call
Avoid waking up every thread sleeping in a futex_wait call during
suspend and resume by calling a freezable blocking call.  Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Darren Hart <dvhart@linux.intel.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:22 +02:00
Colin Cross 9745cdb36d select: use freezable blocking call
Avoid waking up every thread sleeping in a select call during
suspend and resume by calling a freezable blocking call.  Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:22 +02:00
Colin Cross 1c441e9212 epoll: use freezable blocking call
Avoid waking up every thread sleeping in an epoll_wait call during
suspend and resume by calling a freezable blocking call.  Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:22 +02:00
Colin Cross e2610b268b binder: use freezable blocking calls
Avoid waking up every thread sleeping in a binder call during
suspend and resume by calling a freezable blocking call.  Previous
patches modified the freezer to avoid sending wakeups to threads
that are blocked in freezable blocking calls.

This call was selected to be converted to a freezable call because
it doesn't hold any locks or release any resources when interrupted
that might be needed by another freezing task or a kernel driver
during suspend, and is a common site where idle userspace tasks are
blocked.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:22 +02:00
Colin Cross dd5ec0f4e7 freezer: add new freezable helpers using freezer_do_not_count()
Freezing tasks will wake up almost every userspace task from
where it is blocking and force it to run until it hits a
call to try_to_sleep(), generally on the exit path from the syscall
it is blocking in.  On resume each task will run again, usually
restarting the syscall and running until it hits the same
blocking call as it was originally blocked in.

To allow tasks to avoid running on every suspend/resume cycle,
this patch adds additional freezable wrappers around blocking calls
that call freezer_do_not_count().  Combined with the previous patch,
these tasks will not run during suspend or resume unless they wake
up for another reason, in which case they will run until they hit
the try_to_freeze() in freezer_count(), and then continue processing
the wakeup after tasks are thawed.

Additional patches will convert the most common locations that
userspace blocks in to use freezable helpers.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:22 +02:00
Colin Cross 8ee492d659 freezer: convert freezable helpers to static inline where possible
Some of the freezable helpers have to be macros because their
condition argument needs to get evaluated every time through
the wait loop.  Convert the others to static inline to make
future changes easier.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:22 +02:00
Colin Cross b01235861b freezer: convert freezable helpers to freezer_do_not_count()
Freezing tasks will wake up almost every userspace task from
where it is blocking and force it to run until it hits a
call to try_to_sleep(), generally on the exit path from the syscall
it is blocking in.  On resume each task will run again, usually
restarting the syscall and running until it hits the same
blocking call as it was originally blocked in.

Convert the existing wait_event_freezable* wrappers to use
freezer_do_not_count().  Combined with a previous patch,
these tasks will not run during suspend or resume unless they wake
up for another reason, in which case they will run until they hit
the try_to_freeze() in freezer_count(), and then continue processing
the wakeup after tasks are thawed.

This results in a small change in behavior, previously a race
between freezing and a normal wakeup would be won by the wakeup,
now the task will freeze and then handle the wakeup after thawing.

Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:22 +02:00
Colin Cross 613f5d13b5 freezer: skip waking up tasks with PF_FREEZER_SKIP set
Android goes through suspend/resume very often (every few seconds when
on a busy wifi network with the screen off), and a significant portion
of the energy used to go in and out of suspend is spent in the
freezer.  If a task has called freezer_do_not_count(), don't bother
waking it up.  If it happens to wake up later it will call
freezer_count() and immediately enter the refrigerator.

Combined with patches to convert freezable helpers to use
freezer_do_not_count() and convert common sites where idle userspace
tasks are blocked to use the freezable helpers, this reduces the
time and energy required to suspend and resume.

Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:22 +02:00
Colin Cross 18ad0c6297 freezer: shorten freezer sleep time using exponential backoff
All tasks can easily be frozen in under 10 ms, switch to using
an initial 1 ms sleep followed by exponential backoff until
8 ms.  Also convert the printed time to ms instead of centiseconds.

Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:22 +02:00
Colin Cross 1b1d2fb444 lockdep: remove task argument from debug_check_no_locks_held
The only existing caller to debug_check_no_locks_held calls it
with 'current' as the task, and the freezer needs to call
debug_check_no_locks_held but doesn't already have a current
task pointer, so remove the argument.  It is already assuming
that the current task is relevant by dumping the current stack
trace as part of the warning.

This was originally part of 6aa9707099 (lockdep: check that
no locks held at freeze time) which was reverted in
dbf520a9d7.

Original-author: Mandeep Singh Baines <msb@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:21 +02:00
Colin Cross 5853cc2a89 freezer: add unsafe versions of freezable helpers for CIFS
CIFS calls wait_event_freezekillable_unsafe with a VFS lock held,
which is unsafe and will cause lockdep warnings when 6aa9707
"lockdep: check that no locks held at freeze time" is reapplied
(it was reverted in dbf520a).  CIFS shouldn't be doing this, but
it has long-running syscalls that must hold a lock but also
shouldn't block suspend.  Until CIFS freeze handling is rewritten
to use a signal to exit out of the critical section, add a new
wait_event_freezekillable_unsafe helper that will not run the
lockdep test when 6aa9707 is reapplied, and call it from CIFS.

In practice the likley result of holding the lock while freezing
is that a second task blocked on the lock will never freeze,
aborting suspend, but it is possible to manufacture a case using
the cgroup freezer, the lock, and the suspend freezer to create
a deadlock.  Silencing the lockdep warning here will allow
problems to be found in other drivers that may have a more
serious deadlock risk, and prevent new problems from being added.

Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:21 +02:00
Colin Cross 416ad3c9c0 freezer: add unsafe versions of freezable helpers for NFS
NFS calls the freezable helpers with locks held, which is unsafe
and will cause lockdep warnings when 6aa9707 "lockdep: check
that no locks held at freeze time" is reapplied (it was reverted
in dbf520a).  NFS shouldn't be doing this, but it has
long-running syscalls that must hold a lock but also shouldn't
block suspend.  Until NFS freeze handling is rewritten to use a
signal to exit out of the critical section, add new *_unsafe
versions of the helpers that will not run the lockdep test when
6aa9707 is reapplied, and call them from NFS.

In practice the likley result of holding the lock while freezing
is that a second task blocked on the lock will never freeze,
aborting suspend, but it is possible to manufacture a case using
the cgroup freezer, the lock, and the suspend freezer to create
a deadlock.  Silencing the lockdep warning here will allow
problems to be found in other drivers that may have a more
serious deadlock risk, and prevent new problems from being added.

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-05-12 14:16:21 +02:00
Colin Cross d38e0e3fed Revert "Staging: Android alarm: IOCTL command encoding fix"
Commit 6bd4a5d96c changed the
ANDROID_ALARM_GET_TIME ioctls from IOW to IOR.  While technically
correct, the _IOC_DIR bits are ignored by alarm_ioctl, so the
commit breaks a userspace ABI used by all existing Android devices
for a purely cosmetic reason.  Revert it.

Cc: stable <stable@vger.kernel.org>
Cc: Dae S. Kim <dae@velatum.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-13 13:04:43 -08:00
Colin Cross cd8ce15903 ARM: OMAP4: retrigger localtimers after re-enabling gic
'Workaround for ROM bug because of CA9 r2pX gic control'
register change disables the gic distributor while the secondary
cpu is being booted.  If a localtimer interrupt on the primary cpu
occurs when the distributor is turned off, the interrupt is lost,
and the localtimer never fires again.

Make the primary cpu wait for the secondary cpu to reenable the
gic distributor (with interrupts off for safety), and then
check if the pending bit is set in the localtimer but not the
gic.  If so, ack it in the localtimer, and reset the timer with
the minimum timeout to trigger a new timer interrupt.

Signed-off-by: Colin Cross <ccross@android.com>
[s-jan@ti.com: adapted to k3.4 + validated functionality]
Signed-off-by: Sebastien Jan <s-jan@ti.com>
[t-kristo@ti.com: dropped generic ARM kernel exports from the code, rebased
 to mainline]
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
2012-11-05 14:26:43 -08:00
Colin Cross 619271353d ARM: SAMSUNG: call clk_get_rate for debugfs rate files
c->rate is rarely set, call clk_get_rate on the clock to print
the value in /d/clock/.../rate.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2012-10-23 19:19:22 +09:00
Colin Cross 52569e2f17 ARM: SAMSUNG: add clock_tree debugfs file in clock
Add a clock/clock_tree debugfs file that shows the entire clock
hierarchy including usage counts and rates.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
[kgene.kim@samsung.com: silence checkpatch complaining]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2012-10-23 19:11:09 +09:00
Colin Cross 9d7d6e363b ARM: OMAP: counter: add locking to read_persistent_clock
read_persistent_clock uses a global variable, use a spinlock to
ensure non-atomic updates to the variable don't overlap and cause
time to move backwards.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: R Sricharan <r.sricharan@ti.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tony Lindgren <tony@atomide.com>
2012-10-08 14:01:12 -07:00
Colin Cross 52c47742f7 leds: triggers: send uevent when changing triggers
Some triggers create sysfs files when they are enabled. Send a uevent
"change" notification whenever the trigger is changed to allow userspace
processes such as udev to modify permissions on the new files.

A change notification will also be sent during registration of led class
devices or led triggers if the default trigger of an led class device
is found.

(bryan.wu@canonical.com: rename trigger to trig to fix the build error)

Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
2012-09-11 18:32:41 +08:00
Colin Cross 63c6ba4352 cpuidle: coupled: fix sleeping while atomic in cpu notifier
The cpu hotplug notifier gets called in both atomic and non-atomic
contexts, it is not always safe to lock a mutex.  Filter out all events
except the six necessary ones, which are all sleepable, before taking
the mutex.

Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-08-17 19:37:01 +02:00
Colin Cross 237ec6f2e5 ARM: 7486/1: sched_clock: update epoch_cyc on resume
Many clocks that are used to provide sched_clock will reset during
suspend.  If read_sched_clock returns 0 after suspend, sched_clock will
appear to jump forward.  This patch resets cd.epoch_cyc to the current
value of read_sched_clock during resume, which causes sched_clock() just
after suspend to return the same value as sched_clock() just before
suspend.

In addition, during the window where epoch_ns has been updated before
suspend, but epoch_cyc has not been updated after suspend, it is unknown
whether the clock has reset or not, and sched_clock() could return a
bogus value.  Add a suspended flag, and return the pre-suspend epoch_ns
value during this period.

The new behavior is triggered by calling setup_sched_clock_needs_suspend
instead of setup_sched_clock.

Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-11 09:15:58 +01:00
Colin Cross 24b35521b8 ARM: 7477/1: vfp: Always save VFP state in vfp_pm_suspend on UP
vfp_pm_suspend should save the VFP state in suspend after
any lazy context switch.  If it only saves when the VFP is enabled,
the state can get lost when, on a UP system:
  Thread 1 uses the VFP
  Context switch occurs to thread 2, VFP is disabled but the
     VFP context is not saved
  Thread 2 initiates suspend
  vfp_pm_suspend is called with the VFP disabled, and the unsaved
     VFP context of Thread 1 in the registers

Modify vfp_pm_suspend to save the VFP context whenever
vfp_current_hw_state is not NULL.

Includes a fix from Ido Yariv <ido@wizery.com>, who pointed out that on
SMP systems, the state pointer can be pointing to a freed task struct if
a task exited on another cpu, fixed by using #ifndef CONFIG_SMP in the
new if clause.

Cc: Barry Song <bs14@csr.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ido Yariv <ido@wizery.com>
Cc: Daniel Drake <dsd@laptop.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-31 10:30:43 +01:00
Colin Cross a84b895a23 ARM: 7476/1: vfp: only clear vfp state for current cpu in vfp_pm_suspend
vfp_pm_suspend runs on each cpu, only clear the hardware state
pointer for the current cpu.  Prevents a possible crash if one
cpu clears the hw state pointer when another cpu has already
checked if it is valid.

Cc: stable@vger.kernel.org
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-31 10:30:42 +01:00
Colin Cross 4c36595ec8 ARM: 7468/1: ftrace: Trace function entry before updating index
Commit 722b3c7469 modified x86 ftrace to
avoid tracing all functions called from irqs when function graph was
used with a filter.  Port the same fix to ARM.

Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-31 10:30:42 +01:00
Colin Cross 064b021fbe PM / Sleep: call early resume handlers when suspend_noirq fails
Commit cf579dfb82 (PM / Sleep: Introduce
"late suspend" and "early resume" of devices) introduced a bug where
suspend_late handlers would be called, but if dpm_suspend_noirq returned
an error the early_resume handlers would never be called.  All devices
would end up on the dpm_late_early_list, and would never be resumed
again.

Fix it by calling dpm_resume_early when dpm_suspend_noirq returns
an error.

Signed-off-by: Colin Cross <ccross@android.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-07-19 10:38:06 +02:00
Colin Cross 20ff51a36b cpuidle: coupled: add parallel barrier function
Adds cpuidle_coupled_parallel_barrier, which can be used by coupled
cpuidle state enter functions to handle resynchronization after
determining if any cpu needs to abort.  The normal use case will
be:

static bool abort_flag;
static atomic_t abort_barrier;

int arch_cpuidle_enter(struct cpuidle_device *dev, ...)
{
	if (arch_turn_off_irq_controller()) {
	   	/* returns an error if an irq is pending and would be lost
		   if idle continued and turned off power */
		abort_flag = true;
	}

	cpuidle_coupled_parallel_barrier(dev, &abort_barrier);

	if (abort_flag) {
	   	/* One of the cpus didn't turn off it's irq controller */
	   	arch_turn_on_irq_controller();
		return -EINTR;
	}

	/* continue with idle */
	...
}

This will cause all cpus to abort idle together if one of them needs
to abort.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-06-02 00:49:36 -04:00
Colin Cross 4126c0197b cpuidle: add support for states that affect multiple cpus
On some ARM SMP SoCs (OMAP4460, Tegra 2, and probably more), the
cpus cannot be independently powered down, either due to
sequencing restrictions (on Tegra 2, cpu 0 must be the last to
power down), or due to HW bugs (on OMAP4460, a cpu powering up
will corrupt the gic state unless the other cpu runs a work
around).  Each cpu has a power state that it can enter without
coordinating with the other cpu (usually Wait For Interrupt, or
WFI), and one or more "coupled" power states that affect blocks
shared between the cpus (L2 cache, interrupt controller, and
sometimes the whole SoC).  Entering a coupled power state must
be tightly controlled on both cpus.

The easiest solution to implementing coupled cpu power states is
to hotplug all but one cpu whenever possible, usually using a
cpufreq governor that looks at cpu load to determine when to
enable the secondary cpus.  This causes problems, as hotplug is an
expensive operation, so the number of hotplug transitions must be
minimized, leading to very slow response to loads, often on the
order of seconds.

This file implements an alternative solution, where each cpu will
wait in the WFI state until all cpus are ready to enter a coupled
state, at which point the coupled state function will be called
on all cpus at approximately the same time.

Once all cpus are ready to enter idle, they are woken by an smp
cross call.  At this point, there is a chance that one of the
cpus will find work to do, and choose not to enter idle.  A
final pass is needed to guarantee that all cpus will call the
power state enter function at the same time.  During this pass,
each cpu will increment the ready counter, and continue once the
ready counter matches the number of online coupled cpus.  If any
cpu exits idle, the other cpus will decrement their counter and
retry.

To use coupled cpuidle states, a cpuidle driver must:

   Set struct cpuidle_device.coupled_cpus to the mask of all
   coupled cpus, usually the same as cpu_possible_mask if all cpus
   are part of the same cluster.  The coupled_cpus mask must be
   set in the struct cpuidle_device for each cpu.

   Set struct cpuidle_device.safe_state to a state that is not a
   coupled state.  This is usually WFI.

   Set CPUIDLE_FLAG_COUPLED in struct cpuidle_state.flags for each
   state that affects multiple cpus.

   Provide a struct cpuidle_state.enter function for each state
   that affects multiple cpus.  This function is guaranteed to be
   called on all cpus at approximately the same time.  The driver
   should ensure that the cpus all abort together if any cpu tries
   to abort once the function is called.

update1:

cpuidle: coupled: fix count of online cpus

online_count was never incremented on boot, and was also counting
cpus that were not part of the coupled set.  Fix both issues by
introducting a new function that counts online coupled cpus, and
call it from register as well as the hotplug notifier.

update2:

cpuidle: coupled: fix decrementing ready count

cpuidle_coupled_set_not_ready sometimes refuses to decrement the
ready count in order to prevent a race condition.  This makes it
unsuitable for use when finished with idle.  Add a new function
cpuidle_coupled_set_done that decrements both the ready count and
waiting count, and call it after idle is complete.

Cc: Amit Kucheria <amit.kucheria@linaro.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Trinabh Gupta <g.trinabh@gmail.com>
Cc: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-06-02 00:49:09 -04:00
Colin Cross 3af272ab75 cpuidle: fix error handling in __cpuidle_register_device
Fix the error handling in __cpuidle_register_device to include
the missing list_del.  Move it to a label, which will simplify
the error handling when coupled states are added.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-06-02 00:48:49 -04:00
Colin Cross 56cfbf74a1 cpuidle: refactor out cpuidle_enter_state
Split the code to enter a state and update the stats into a helper
function, cpuidle_enter_state, and export it.  This function will
be called by the coupled state code to handle entering the safe
state and the final coupled state.

Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Kevin Hilman <khilman@ti.com>
Signed-off-by: Colin Cross <ccross@android.com>
Reviewed-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-06-02 00:48:31 -04:00
Colin Cross 454c79999f sched/rt: Fix SCHED_RR across cgroups
task_tick_rt() has an optimization to only reschedule SCHED_RR tasks
if they were the only element on their rq.  However, with cgroups
a SCHED_RR task could be the only element on its per-cgroup rq but
still be competing with other SCHED_RR tasks in its parent's
cgroup.  In this case, the SCHED_RR task in the child cgroup would
never yield at the end of its timeslice.  If the child cgroup
rt_runtime_us was the same as the parent cgroup rt_runtime_us,
the task in the parent cgroup would starve completely.

Modify task_tick_rt() to check that the task is the only task on its
rq, and that the each of the scheduling entities of its ancestors
is also the only entity on its rq.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1337229266-15798-1-git-send-email-ccross@android.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-30 14:02:25 +02:00
Colin Cross fde165b2a2 ARM: 7414/1: SMP: prevent use of the console when using idmap_pgd
Commit 4e8ee7de22 (ARM: SMP: use
idmap_pgd for mapping MMU enable during secondary booting)
switched secondary boot to use idmap_pgd, which is initialized
during early_initcall, instead of a page table initialized during
__cpu_up.  This causes idmap_pgd to contain the static mappings
but be missing all dynamic mappings.

If a console is registered that creates a dynamic mapping, the
printk in secondary_start_kernel will trigger a data abort on
the missing mapping before the exception handlers have been
initialized, leading to a hang.  Initial boot is not affected
because no consoles have been registered, and resume is usually
not affected because the offending console is suspended.
Onlining a cpu with hotplug triggers the problem.

A workaround is to the printk in secondary_start_kernel until
after the page tables have been switched back to init_mm.

Cc: <stable@vger.kernel.org>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-05-06 11:10:41 +01:00
Colin Cross 099f5d01a6 android: make persistent_ram based drivers depend on HAVE_MEMBLOCK
m68k doesn't have memblock_reserve, which causes a build failure
with allmodconfig.  Make PERSISTENT_RAM and RAM_CONSOLE depend on
HAVE_MEMBLOCK.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reported-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-10 09:48:29 -07:00
Colin Cross fd9abe1b5b ARM: EXYNOS: fix CONFIG_DEBUG_LL
addruart cannot read from the physical address of the chipid
register, that will fail as soon as the mmu is turned on.
Fixing it to read from the physical or virtual address depending
on the mmu state also does not work, because there is a period
between head.S and exynos_map_io where the mmu is on, the uart
is mapped and used, but the chipid mapping is not yet present.

Fix addruart to use the ARM Main ID cp15 register to determine
if the core is Cortex A15 (EXYNOS5) or not (EXYNOS4).

Signed-off-by: Colin Cross <ccross@android.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2012-04-04 09:27:19 -07:00
Colin Cross 3a21138d3f staging: android: ram_console: fix crash in ram_console_late_init
If the persistent ram buffer is not available, ram_console_late_init
would crash when dereferencing ram_console_zone.  Return early if
ram console was not initialized.

CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08 09:37:09 -08:00
Colin Cross a15d0b365e staging: android: persistent_ram: add notrace to persistent_ram_write
Add the notrace attribute to persistent_ram_write and the
non-ecc functions that it calls to allow persistent_ram to
be used for ftracing (only when ecc is disabled).

CC: Greg KH <gregkh@linuxfoundation.org>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08 09:36:08 -08:00
Colin Cross 808d0387eb staging: android: persistent_ram: make persistent_ram_write atomic
Allow persistent_ram_write to be called on multiple cpus at
the same time, as long as ecc is not in use.  Uses atomics
for the buffer->start and buffer->size counters.

[jstultz: Fix up some pr_info casting issues on 64bit]
CC: Greg KH <gregkh@linuxfoundation.org>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08 09:36:08 -08:00
Colin Cross 404a604338 staging: android: persistent_ram: handle reserving and mapping memory
Replace the ioremapped memory passed in from the drivers with
a memblock_reserve and vmap.  Adds a new function,
persistent_ram_early_init, designed to be called from the machine
init_early callback, that calls memblock_remove and saves the
provided persistent ram area layout.

Drivers only pass in their struct device * and ecc settings.
Locating and mapping the memory is now handled entirely within
persistent_ram.

Also, convert ram_console to the new persistent_ram_init
parameters that only take a struct device * and ecc settings.

[jstultz: Fix pr_info casting issues on 64bit, folded two
patches as the build breaks if they are apart. Also replaced
phys_to_page() w/ pfn_to_page(addr>>PAGE_SHIFT), as phys_to_page
is only on a few arches.]
CC: Greg KH <gregkh@linuxfoundation.org>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08 09:36:08 -08:00
Colin Cross 9cc05ad97c staging: android: persistent_ram: refactor ecc support
Remove CONFIG_ANDROID_RAM_CONSOLE_ERROR_CORRECTION and related
 #ifdefs.  Also allow persistent ram zones without ecc enabled.
For some use cases, like the data portion of the upcoming
persistent_vars patches, or a persistent ftrace ringbuffer,
ecc on every update is too expensive.

CC: Greg KH <gregkh@linuxfoundation.org>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08 09:36:08 -08:00
Colin Cross c672528aec staging: android: ram_console: split out persistent ram
Split ram_console into two halves.

persistent_ram is a set of apis that handle a block of memory
that does not get erased across a reboot.  It provides functions
to fill it as a single buffer or a ring buffer, and to extract
the old data after a reboot.  It handles ecc on the data to
correct bit errors introduced during reboot.

ram_console is now a small wrapper around persistent_ram that
feeds console data into the ringbuffer, and exports the old
data to /proc/last_kmsg after a reboot.

[jstultz: Moved persistent_ram.h to staging dir]
CC: Greg KH <gregkh@linuxfoundation.org>
CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08 09:36:08 -08:00
Colin Cross c5ee1211f2 staging: android: ram_console: drop verbose ram_console support
Equivalent functionality can be obtained with loglevel=15

CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-07 18:32:40 -08:00
Colin Cross 8294e2362f staging: android: ram_console: drop early buffer support
Early ramconsole is not very useful, an early crash will prevent
getting the logged data out on the next boot, and CONFIG_DEBUG_LL=y
will get the same information.  Drop it to simplify a future
refactoring.

CC: Android Kernel Team <kernel-team@android.com>
Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-07 18:32:40 -08:00