arm64: Replace set_arch_dma_coherent_ops with arch_setup_dma_ops

Commit a3a60f81ee6f (dma-mapping: replace set_arch_dma_coherent_ops with
arch_setup_dma_ops) changes the of_dma_configure() arch dma_ops callback
to arch_setup_dma_ops but only the arch/arm code is updated. Subsequent
commit 97890ba9289c (dma-mapping: detect and configure IOMMU in
of_dma_configure) changes the arch_setup_dma_ops() prototype further to
handle iommu. The patch makes the corresponding arm64 changes.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Will Deacon <will.deacon@arm.com>
arm64: kernel: fix __cpu_suspend mm switch on warm-boot

On arm64 the TTBR0_EL1 register is set to either the reserved TTBR0
page tables on boot or to the active_mm mappings belonging to user space
processes, it must never be set to swapper_pg_dir page tables mappings.

When a CPU is booted its active_mm is set to init_mm even though its
TTBR0_EL1 points at the reserved TTBR0 page mappings. This implies
that when __cpu_suspend is triggered the active_mm can point at
init_mm even if the current TTBR0_EL1 register contains the reserved
TTBR0_EL1 mappings.

Therefore, the mm save and restore executed in __cpu_suspend might
turn out to be erroneous in that, if the current->active_mm corresponds
to init_mm, on resume from low power it ends up restoring in the
TTBR0_EL1 the init_mm mappings that are global and can cause speculation
of TLB entries which end up being propagated to user space.

This patch fixes the issue by checking the active_mm pointer before
restoring the TTBR0 mappings. If the current active_mm == &init_mm,
the code sets the TTBR0_EL1 to the reserved TTBR0 mapping instead of
switching back to the active_mm, which is the expected behaviour
corresponding to the TTBR0_EL1 settings when __cpu_suspend was entered.

Fixes: 95322526ef62 ("arm64: kernel: cpu_{suspend/resume} implementation")
Cc: <stable@vger.kernel.org> # 3.14+: 18ab7db
Cc: <stable@vger.kernel.org> # 3.14+: 714f599
Cc: <stable@vger.kernel.org> # 3.14+: c3684fb
Cc: <stable@vger.kernel.org> # 3.14+
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: defconfig: defconfig update for 3.19

The usual defconfig tweaks, this time:

  - FHANDLE and AUTOFS4_FS to keep systemd happy
  - PID_NS, QUOTA and KEYS to keep LTP happy
  - Disable DEBUG_PREEMPT, as this *really* hurts performance

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: mm: Add pgd_page to support RCU fast_gup

This patch adds pgd_page definition in order to keep supporting
HAVE_GENERIC_RCU_GUP configuration. In addition, it changes pud_page
expression to align with pmd_page for readability.

An introduction of pgd_page resolves the following build breakage
under 4KB + 4Level memory management combo.

mm/gup.c: In function 'gup_huge_pgd':
mm/gup.c:889:2: error: implicit declaration of function 'pgd_page' [-Werror=implicit-function-declaration]
  head = pgd_page(orig);
  ^
mm/gup.c:889:7: warning: assignment makes pointer from integer without a cast
  head = pgd_page(orig);

Cc: Will Deacon <will.deacon@arm.com>
Cc: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com>
[catalin.marinas@arm.com: remove duplicate pmd_page definition]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 fixes from Catalin Marinas:
 - __cpu_suspend mm switching fix after warm boot
 - arch_setup_dma_ops implementation
 - pgd_page compilation error fix
 - defconfig updates

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: mm: Add pgd_page to support RCU fast_gup
  arm64: defconfig: defconfig update for 3.19
  arm64: kernel: fix __cpu_suspend mm switch on warm-boot
  arm64: Replace set_arch_dma_coherent_ops with arch_setup_dma_ops