smp: patches from mainline 3.5 to hopefully help with hotplug
efficiency

Thomas Gleixner's generic-idle patches:

smp: Add task_struct argument to __cpu_up()
Preparatory patch to make the idle thread allocation for secondary
cpus generic.
http://git.kernel.org/?p=linux/kernel/git/tip/tip.git;a=commit;h=8239c25f47d2b318156993b15f33900a86ea5e17

smp: Add generic smpboot facility
Start a new file, which will hold SMP and CPU hotplug related generic
infrastructure.
http://git.kernel.org/?p=linux/kernel/git/tip/tip.git;a=commit;h=38498a67aa2cf8c80754b8d304bfacc10bc582b5

smp: Provide generic idle thread allocation
All SMP architectures have magic to fork the idle task and to store it
for reusage when cpu hotplug is enabled. Provide a generic
infrastructure for it.
Create/reinit the idle thread for the cpu which is brought up in the
generic code and hand the thread pointer to the architecture code via
__cpu_up().
Note, that fork_idle() is called via a workqueue, because this
guarantees that the idle thread does not get a reference to a user
space VM. This can happen when the boot process did not bring up all
possible cpus and a later cpu_up() is initiated via the sysfs
interface. In that case fork_idle() would be called in the context of
the user space task and take a reference on the user space VM.
http://git.kernel.org/?p=linux/kernel/git/tip/tip.git;a=commit;h=29d5e0476e1c4a513859e7858845ad172f560389

arm: Use generic idle thread allocation
http://git.kernel.org/?p=linux/kernel/git/tip/tip.git;a=commit;h=84ec6d5796e095e2f8698bd2b5d33849ed26d9e2

Conflicts:
	arch/arm/kernel/smp.c
	kernel/cpu.c
Underclocking down to 96MHZ (Credits showp)

optimizing frequencies
iommu: msm: Use ion_phys_addr_t for iova argument

IOMMU mapping function is using the wrong type for its
IO Virtual Address (IOVA) causing the returned address
to contain garbage in the upper 32 bits when LPAE is enabled.

CRs-fixed: 564365
Change-Id: Ied592fe855a145b0ff32d2a6228ecfcf7fd0a53e
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
msm: acpuclock-krait: Program both high- and low-performance sources

The latest LDO/BHS switching sequence employed in the 8974
krait-regulator driver involves mandatory operations that cause
the CPUs to switch to the low-performance clock source when the
CPU is powered from the LDO, and to the high-performance clock
source when powered from the BHS.

This results in potential undervolting of the CPUs since the
acpuclock driver does not program the low-performance source,
and the clock source it selects be default is running at the
same speed as DDR (which can be very fast).

Fix this by programming both the high and low-performance clock
sources to be the same at all times.

CRs-Fixed: 538629
Change-Id: Iaa39cca9165b892e52acd8ec3aac5d0784112623
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
msm: acpuclock-krait: Fix HFPLL regulator voting in regulator_init()

Simply incrementing l2_vreg_count is not enough to ensure the
regulators necessary for the L2 HFPLL are enabled. Instead,
enable_l2_regulators() must be called to place votes for the
regulators.

This problem will only result in incorrect behaviour (a missing
vote for the HFPLL regulators) if the L2 rate detected at boot is
not in the frequency table. In all other cases, the vote will be
applied as part of the hfpll_enable call when init_clock_sources()
is called for the L2.

Fix the code so that the voting works correctly even if the initial
L2 rate is not in the frequency table.

Change-Id: I8e84cd81de17a0efcc91281848180cf34ef9bb57
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
msm: acpuclock-krait: Update 'unknown rate' debug prints to warnings

While not fatal, boot performance will be suboptimal if the L2 or
CPU frequencies at boot are not in the frequency tables. This is
because acpuclock 'plays it safe' by applying the lowest possible
clock rate in such situations to ensure clocks are not set higher
than boot-up voltages can support.

Change-Id: I07fcff70d742b2590fa996ea4ca7a1f1c560eee3
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
lib: devres: Introduce devm_ioremap_resource()

The devm_request_and_ioremap() function is very useful and helps avoid a
whole lot of boilerplate. However, one issue that keeps popping up is
its lack of a specific error code to determine which of the steps that
it performs failed. Furthermore, while the function gives an example and
suggests what error code to return on failure, a wide variety of error
codes are used throughout the tree.

In an attempt to fix these problems, this patch adds a new function that
drivers can transition to. The devm_ioremap_resource() returns a pointer
to the remapped I/O memory on success or an ERR_PTR() encoded error code
on failure. Callers can check for failure using IS_ERR() and determine
its cause by extracting the error code using PTR_ERR().

devm_request_and_ioremap() is implemented as a wrapper around the new
API and return NULL on failure as before. This ensures that backwards
compatibility is maintained until all users have been converted to the
new API, at which point the old devm_request_and_ioremap() function
should be removed.

A semantic patch is included which can be used to convert from the old
devm_request_and_ioremap() API to the new devm_ioremap_resource() API.
Some non-trivial cases may require manual intervention, though.

Change-Id: I458afe18768979122c12e95bffe979a31f02f607
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 75096579c3ac39ddc2f8b0d9a8924eba31f4d920
Git-repo: https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: Use list_for_each_safe on error path

On an error, the list of pages is walked and destroyed. Since the list
is being destroyed, use list_for_each_safe to avoid list corruption.

Change-Id: Ia397a11d2d890b3458745820c79df2adaa088ade
CRs-Fixed: 565183
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: Also shrink memory cached in the deferred free list

When the system is low on memory, we want to shrink any cached
system memory ion is holding.  Previously we were shrinking memory
in the page pools, but not in the deferred free list.  This patch
makes it possible to shrink both.  It also moves the shrinker
code into the heaps so they can correctly manage any caches they
might contain.

Change-Id: I177f587f999a5220eddbf7af94745aae736cac75
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
Git-commit: 072beca55150c0c0b652bbb24267da271e0bdf19
Git-repo: https://android.googlesource.com/kernel/common
[mitchelh@codeaurora.org: minor context fixups due to MSM changes]
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: Add buffer flag to skip page pooling on free

Currently, when we free a buffer it might actually just go back into a
heap-specific page pool rather than going back to the system. This poses
a problem because sometimes (like when we're running a shrinker in low
memory conditions) we need to force the memory associated with the
buffer to truly be relinquished to the system rather than just going
back into a page pool.

There isn't an obvious use case for this flag by Ion clients. The main
use case right now is to provide a mechanism for the deferred free code
to force stale buffers to bypass page pooling.

Change-Id: I724f89cc037083fe8576784363caa18a34e8705a
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: create separate heap and client debugfs directories

It can be slightly annoying to figure out which files under the ion
debugfs directory are heap debug files and which ones are client debug
files. Create separate subdirectories under ion to hold the different
types of debug files.

Change-Id: Ic773ab619ef94b9b4d0f3794def9d37645c7c212
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: don't use "vmalloc" for system heap readable name

The human-readable name of the system heap is currently "vmalloc", which
is misleading since we don't use vmalloc at all for that heap, we use
alloc_pages. Make the human-readable name of the heap "system".

Change-Id: Iefb92ea8adc8d76b8eccc504010aa9bc2fa5c50c
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: optimize zero'ing of pages

Instead of using __GFP_ZERO, vmap high-order pages for zero'ing all at
once (or in a few large chunks).

Test results show a ~25% speedup for allocations that are fulfilled from
lowmem, and ~100% speedup for allocations that are fulfilled from
highmem.

Change-Id: I57270361ff195780370e1c6f458985bdbb641efe
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: add page pooling to cached allocations from the system heap

Add a page pool for cached allocations from the system heap.

Change-Id: I6d7688026ff4ee65efa047a164652da1427e72c4
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: make sure all clients are exposed in debugfs

Currently, if multiple Ion clients are created with the same name, only
the first one shows up in debugfs. Rectify this by adding a
monotonically-increasing serial number to the debug names of Ion
clients.

CRs-Fixed: 566001
Change-Id: I000e45055d5029c7bccd88c36b238736929da3a5
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: Support probe deferal for client creation

Ion is treated like any other device in the system. Clients
may try to initialize before Ion is setup. If the Ion driver
has not yet probed, return -EPROBE_DEFER to try again later.
Since the flow is being restructured to support probe deferal,
also include some better error handling for when Ion returns
an error while probing.

Change-Id: I7ee6dde2c837fba8bba0ba4aaddee3af37b2fec1
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: fix zero'ing of cached buffers in system heap

Currently, in the system heap we zero out buffers at free-time when they
came from uncached allocations. The reason for this is that uncached
allocations come from the page pools, which require this free-time
zero'ing. However, the assumption that a buffer came from the page pools
iff it was an uncached allocation is no longer valid since [0204b38
"gpu: ion: add page pooling to cached allocations from the system heap"]
introduced page pooling for cached allocations as well. This results in
us not zero'ing out cached buffers before putting them back in the page
pools, which is a security bug (we could potentially leak sensitive
information).

Fix this by zero'ing out all buffers that are going back into the page
pools (cached and uncached).

Change-Id: I5c51eca75c8cc3b3823df1494bb0eef295c77b86
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: kmalloc_heap: flush cpu caches at allocation time

There's currently a problem with the kmalloc heap where buffers
occasionally come through unzero'd when mmap'd to userspace, which is a
security hole. We actually are zero'ing the buffer but that data isn't
immediately visible to folks with other mappings to the memory (e.g. the
mapping set up for userspace by the mmap handler). Fix this by flushing
the cpu caches at alloc time.

Change-Id: I3895c6bc163e2d065b48cae66e99825c5c0a865b
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: system_heap: invalidate cache on cached pool allocations

We need to invalidate the cache when allocating pages for the cached
page pools to avoid the possibility of a stale cached value from a
different mapping being written back after we allocate our page.

Change-Id: I9b0ebfd143850cf4a4ef309a264f947a57abff77
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
gpu: ion: use a list instead of a tree for heap debug memory map

Currently we use an rb tree to store information about the memory map
which gets passed to the heap print_debug functions. The reason for
using a tree instead of a simple list is to maintain sortedness as we
build the memory map. However, it can be necessary to store multiple
entries for the same address in the memory map since there can be
multiple clients with handles to the same buffer. This information is
interesting and useful but we currently can't store and display it since
the rb tree requires that the key used for sorting (the physical address
in this case) be unique. Fix this by replacing the rb tree with a linked
list. In order to maintain sorted output of the print_debug functions,
sort the list by physical address after fully building the list.

This also has the positive side-effect of simplifying the code and
making future print_debug methods less error-prone.

CRs-Fixed: 571918
Change-Id: I5b129fd809fb53c66042eab10d096238a34c2b20
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>