msm: kgsl: better handling of virtual address fragmentation

When KGSL_MEMFLAGS_USE_CPU_MAP is enabled, the mmap address
must try to match the GPU alignment requirements of the buffer,
as well as include space in the mapping for the guard page.
This can cause -ENOMEM to be returned from get_unmapped_area()
when there are a large number of mappings. When this happens,
fall back to page alignment and retry to avoid failure.

Change-Id: I2176fe57afc96d8cf1fe1c694836305ddc3c3420
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
msm: kgsl: prevent race between mmap() and free on timestamp

When KGSL_MEMFLAGS_USE_CPU_MAP is set, we must check that the
address from get_unmapped_area() is not used as part of a
mapping that is present only in the GPU pagetable and not the
CPU pagetable. These mappings can occur because when a buffer
is freed on timestamp, the CPU mapping is destroyed immediately
but the GPU mapping is not destroyed until the GPU timestamp
has passed.

Because kgsl_mem_entry_detach_process() removed the rbtree
entry before removing the iommu mapping, there was a window
of time where kgsl thought the address was available even
though it was still present in the iommu pagetable. This
could cause the address to get assigned to a new buffer,
which would cause iommu_map_range() to fail since the old
mapping was still in the pagetable. Prevent this race by
removing the iommu mapping before removing the rbtree entry
tracking the address.

Change-Id: I8f42d6d97833293b55fcbc272d180564862cef8a
CRs-Fixed: 480222
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
msm: kgsl: add guard page support for imported memory

Imported memory buffers sometimes do not have enough
padding to prevent page faults due to overzealous
GPU prefetch. Attach guard pages to their mappings
to prevent these faults.

Because we don't create the scatterlist for some
types of imported memory, such as ion, the guard
page is no longer included as the last entry in
the scatterlist. Instead, it is handled by
size ajustments and a separate iommu_map() call
in the kgsl_mmu_map() and kgsl_mmu_unmap() paths.

Change-Id: I3af3c29c3983f8cacdc366a2423f90c8ecdc3059
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
msm: kgsl: fix kgsl_mem_entry refcounting

Make kgsl_sharedmem_find* return a reference to the
entry that was found. This makes using an entry
without the mem_lock held less race prone.

Change-Id: If6eb6470ecfea1332d3130d877922c70ca037467
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
msm: kgsl: Use the correct length when looking for address collision

Use the right length of allocation from the aligned base address of
CPU virtual map to look for collision in the GPU vitual map. This
prevents discarding of usable address ranges due to false collision
hits.

CRs-Fixed: 492041
Change-Id: I370e6a31f98803e8ca6858a5562f47afeeaa157e
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>
msm: kgsl: Prevent race conditions when freeing memory

Multiple threads can call an ioctl to free a memory region.
Only one of these threads must be allowed to free memory and
the rest can return without freeing. Add a new pending flag
which is tested and set in a critical section guarded by
spinlock to prevent multiple ioctl threads from freeing the
same memory.
Also, a thread could be freeing a memory region that is
in use by another thread. Ensure that the detachment of the
memory from the process list and freeing of the memory always
happens in the same thread. This will prevent a situation where
the memory is being used by a thread which is detached from the
process list and is yet to be freed.
Seperate the selection of gpuaddr and mapping into pagetable. The
gpuaddr assignment needs to be done with process memory lock held
in a critical section but the mapping into pagetable can be done
separately without holding memory lock.

CRs-Fixed: 495144
Change-Id: Idf85fbd4bca29c18597f4b0e737c207f002ab266
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>
msm: kgsl: Only reference the rb_node after taking spinlock

Derefernce the rb node after taking spinlock since the root
node can change and is supposed to be guarded by the spinlock

CRs-Fixed: 495129
Change-Id: I63de7755cf9d5fb548c082f43403000bcef5721b
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>
msm: kgsl: Only initialize process structure once

If the debug root of the process structure is initialized
then it means that the remaining fields will also be
initialized. Check this field at the beginning of the
initialization routine and skip to end of the function. This
also by-passes the reinitialization of some fields because
of errorneous NULL pointer check of rb node. The rb node is
always initialized to NULL so checking if it is NULL to
determine whether the pointer is initialized or not is wrong.

CRs-Fixed: 498014
Change-Id: I73b2124c037187bc96942714dac62c0a72c26372
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>
msm: kgsl: Do not hold memory spinlock when calling find region function

The function kgsl_sharedmem_find_region holds the memory spinlock
at the beginning of the function so we do not need to hold the lock
before calling the function

Change-Id: I20ee32e0ed6aee6ed61cdd4fb7a9cc08a876fc84
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>
msm: kgsl: Add a missing mutex unlock

Adding a missing mutex unlock where we return from
kgsl_late_resume_driver if we fail to wake up the device.

CRs-fixed: 500422
Change-Id: I26b56d95a9427798719fb162d1b1edaf641ae57b
Signed-off-by: Harsh Vardhan Dwivedi <hdwivedi@codeaurora.org>
msm: kgsl: Skip perf counters and Sync lock for A2xx.

Fix includes two changes:

- Skip Perf counters for A2xx since these are intended only for A3xx.
- Don't use GPU-CPU sync lock for A2xx to avoid bootup failure.

Change-Id: I9e1d349b95dd0f6470ab507167b53540f1f1acf7
Signed-off-by: Rajesh Kemisetti <rajeshk@codeaurora.org>
msm: kgsl: Submit a draw command on resume

For A305, submit an extra draw command while resuming the GPU from
SLUMBER state. This fixes corruption seen when the screen is
turned on.

Change-Id: Iafed90b617b0a700ac3f2afcb6d9ecadca590914
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>
msm: kgsl: Add a section to list memory entries in snapshot

Add a section that lists all memory entries of a process
in which the hang has supposedly occurred. The entries are
of (gpuaddr, size, memtype) tuples.

Change-Id: I981d2325346455a6775af1691474c02422581b4f
Signed-off-by: Shubhraprakash Das <sadas@codeaurora.org>
Signed-off-by: Harsh Vardhan Dwivedi <hdwivedi@codeaurora.org>