ARM: dma-mapping: Always pass proper prot flags to iommu_map()

... otherwise it is impossible for the low level iommu driver to
figure out which pte flags should be used.

In __map_sg_chunk we can derive the flags from dma_data_direction.

In __iommu_create_mapping we should treat the memory like
DMA_BIDIRECTIONAL and pass both IOMMU_READ and IOMMU_WRITE to
iommu_map.
__iommu_create_mapping is used during dma_alloc_coherent (via
arm_iommu_alloc_attrs).  AFAIK dma_alloc_coherent is responsible for
allocation _and_ mapping.  I think this implies that access to the
mapped pages should be allowed.

Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Andreas Herrmann <andreas.herrmann@calxeda.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
tpm: xen-tpmfront: fix missing declaration of xen_domain

xen-tpmfront fails to build on arm64 with the following error:

drivers/char/tpm/xen-tpmfront.c: In function ‘xen_tpmfront_init’:
drivers/char/tpm/xen-tpmfront.c:422:2: error: implicit declaration of function ‘xen_domain’ [-Werror=implicit-function-declaration]

Add include of xen/xen.h to fix this.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Ashley Lai <adlai@linux.vnet.ibm.com>
Acked-by: Ashley Lai <adlai@linux.vnet.ibm.com>
Cc: Leonidas Da Silva Barbosa <leosilva@linux.vnet.ibm.com>
Cc: Rajiv Andrade <mail@srajiv.net>
Cc: Marcel Selhorst <tpmdd@selhorst.net>
Cc: Sirrix AG <tpmdd@sirrix.com>
Cc: tpmdd-devel@lists.sourceforge.net
xen: Fix possible user space selector corruption

Due to the way kernel is initialized under Xen is possible that the
ring1 selector used by the kernel for the boot cpu end up to be copied
to userspace leading to segmentation fault in the userspace.

Xen code in the kernel initialize no-boot cpus with correct selectors (ds
and es set to __USER_DS) but the boot one keep the ring1 (passed by Xen).
On task context switch (switch_to) we assume that ds, es and cs already
point to __USER_DS and __KERNEL_CSso these selector are not changed.

If processor is an Intel that support sysenter instruction sysenter/sysexit
is used so ds and es are not restored switching back from kernel to
userspace. In the case the selectors point to a ring1 instead of __USER_DS
the userspace code will crash on first memory access attempt (to be
precise Xen on the emulated iret used to do sysexit will detect and set ds
and es to zero which lead to GPF anyway).

Now if an userspace process call kernel using sysenter and get rescheduled
(for me it happen on a specific init calling wait4) could happen that the
ring1 selector is set to ds and es.

This is quite hard to detect cause after a while these selectors are fixed
(__USER_DS seems sticky).

Bisecting the code commit 7076aada1040de4ed79a5977dbabdb5e5ea5e249 appears
to be the first one that have this issue.

Signed-off-by: Frediano Ziglio <frediano.ziglio@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
of: fix unnecessary warning on missing /cpus node

Not all DT platforms have all the cpus collected under a /cpus node.
That just happens to be a details of FDT, ePAPR and PowerPC platforms.
Sparc does something different, but unfortunately the current code
complains with a warning if /cpus isn't there. This became a problem
with commit f86e4718, "driver/core cpu: initialize of_node in cpu's
device structure", which caused the function to get called for all
architectures.

This commit is a temporary fix to fail silently if the cpus node isn't
present. A proper fix will come later to allow arch code to provide a
custom mechanism for decoding the CPU hwid if the 'reg' property isn't
appropriate.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Cc: David Miller <davem@davemloft.net>
Cc: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Cc: Rob Herring <rob.herring@calxeda.com>
Revert "of: Feed entire flattened device tree into the random pool"

This reverts commit 109b6236294b53d8eaa50be7d9e9ad37079f5f7e.

Tim Bird expressed concern that this will have a bad effect on boot
time, and while simple tests have shown it to be okay with simple tree,
a device tree blob can potentially be quite large and
add_device_randomness() is not a fast function. Rather than do this for
all platforms unconditionally, I'm reverting this patch and would like
to see it revisited. Instead of feeding the entire tree into the random
pool, it would probably be appropriate to hash the tree and feed the
hash result into the pool. There really isn't a lot of randomness in a
device tree anyway. In the majority of cases only a handful of
properties are going to be different between machines with the same
baseboard.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Revert "ARM: init: add support for reserved memory defined by device tree"

This reverts commit 10bcdfb8ba24760f715f0a700c3812747eddddf5. There is
no consensus on the bindings for the reserved memory, so the code for
handing it will be reverted.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Revert "drivers: of: add initialization code for dma reserved memory"

This reverts commit 9d8eab7af79cb4ce2de5de39f82c455b1f796963. There is
still no consensus on the bindings for the reserved memory and various
drawbacks of the proposed solution has been shown, so the best now is to
revert it completely and start again from scratch later.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
KVM: Enable pvspinlock after jump_label_init() to avoid VM hang

We use jump label to enable pv-spinlock. With the changes in (442e0973e927
Merge branch 'x86/jumplabel'), the jump label behaviour has changed
that would result in eventual hang of the VM since we would end up in a
situation where slow path locks would halt the vcpus but we will not be
able to wakeup the vcpu by lock releaser using unlock kick.

Similar problem in Xen and more detailed description is available in
a945928ea270 (xen: Do not enable spinlocks before jump_label_init()
has executed)

This patch splits kvm_spinlock_init to separate jump label changes with
pvops patching and also make jump label enabling after jump_label_init().

Signed-off-by: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Merge tag 'stable/for-linus-3.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

Pull Xen fixes from Stefano Stabellini:
 "A small fix for Xen on x86_32 and a build fix for xen-tpmfront on
  arm64"

* tag 'stable/for-linus-3.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: Fix possible user space selector corruption
  tpm: xen-tpmfront: fix missing declaration of xen_domain
Merge git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull kvm fix from Gleb Natapov.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: Enable pvspinlock after jump_label_init() to avoid VM hang
Merge branch 'fixes-for-v3.12' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping

Pull DMA-mapping fix from Marek Szyprowski:
 "A bugfix for the IOMMU-based implementation of dma-mapping subsystem
  for ARM architecture"

* 'fixes-for-v3.12' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
  ARM: dma-mapping: Always pass proper prot flags to iommu_map()
Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux

Pull device tree fixes and reverts from Grant Likely:
 "One bug fix and three reverts.  The reverts back out the slightly
  controversial feeding the entire device tree into the random pool and
  the reserved-memory binding which isn't fully baked yet.  Expect the
  reserved-memory patches at least to resurface for v3.13.

  The bug fixes removes a scary but harmless warning on SPARC that was
  introduced in the v3.12 merge window.  v3.13 will contain a proper fix
  that makes the new code work on SPARC.

  On the plus side, the diffstat looks *awesome*.  I love removing lines
  of code"

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux:
  Revert "drivers: of: add initialization code for dma reserved memory"
  Revert "ARM: init: add support for reserved memory defined by device tree"
  Revert "of: Feed entire flattened device tree into the random pool"
  of: fix unnecessary warning on missing /cpus node