cbnz/tbnz don't update the condition flags, so remove the "cc" clobbers
from inline asm blocks that only use these instructions to implement
conditional branches.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Linux requires a number of atomic operations to provide full barrier
semantics, that is no memory accesses after the operation can be
observed before any accesses up to and including the operation in
program order.
On arm64, these operations have been incorrectly implemented as follows:
// A, B, C are independent memory locations
<Access [A]>
// atomic_op (B)
1: ldaxr x0, [B] // Exclusive load with acquire
<op(B)>
stlxr w1, x0, [B] // Exclusive store with release
cbnz w1, 1b
<Access [C]>
The assumption here being that two half barriers are equivalent to a
full barrier, so the only permitted ordering would be A -> B -> C
(where B is the atomic operation involving both a load and a store).
Unfortunately, this is not the case by the letter of the architecture
and, in fact, the accesses to A and C are permitted to pass their
nearest half barrier resulting in orderings such as Bl -> A -> C -> Bs
or Bl -> C -> A -> Bs (where Bl is the load-acquire on B and Bs is the
store-release on B). This is a clear violation of the full barrier
requirement.
The simple way to fix this is to implement the same algorithm as ARMv7
using explicit barriers:
<Access [A]>
// atomic_op (B)
dmb ish // Full barrier
1: ldxr x0, [B] // Exclusive load
<op(B)>
stxr w1, x0, [B] // Exclusive store
cbnz w1, 1b
dmb ish // Full barrier
<Access [C]>
but this has the undesirable effect of introducing *two* full barrier
instructions. A better approach is actually the following, non-intuitive
sequence:
<Access [A]>
// atomic_op (B)
1: ldxr x0, [B] // Exclusive load
<op(B)>
stlxr w1, x0, [B] // Exclusive store with release
cbnz w1, 1b
dmb ish // Full barrier
<Access [C]>
The simple observations here are:
- The dmb ensures that no subsequent accesses (e.g. the access to C)
can enter or pass the atomic sequence.
- The dmb also ensures that no prior accesses (e.g. the access to A)
can pass the atomic sequence.
- Therefore, no prior access can pass a subsequent access, or
vice-versa (i.e. A is strictly ordered before C).
- The stlxr ensures that no prior access can pass the store component
of the atomic operation.
The only tricky part remaining is the ordering between the ldxr and the
access to A, since the absence of the first dmb means that we're now
permitting re-ordering between the ldxr and any prior accesses.
From an (arbitrary) observer's point of view, there are two scenarios:
1. We have observed the ldxr. This means that if we perform a store to
[B], the ldxr will still return older data. If we can observe the
ldxr, then we can potentially observe the permitted re-ordering
with the access to A, which is clearly an issue when compared to
the dmb variant of the code. Thankfully, the exclusive monitor will
save us here since it will be cleared as a result of the store and
the ldxr will retry. Notice that any use of a later memory
observation to imply observation of the ldxr will also imply
observation of the access to A, since the stlxr/dmb ensure strict
ordering.
2. We have not observed the ldxr. This means we can perform a store
and influence the later ldxr. However, that doesn't actually tell
us anything about the access to [A], so we've not lost anything
here either when compared to the dmb variant.
This patch implements this solution for our barriered atomic operations,
ensuring that we satisfy the full barrier requirements where they are
needed.
Cc: <stable@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The dsb instruction takes an option specifying both the target access
types and shareability domain.
This patch allows such an option to be passed to the dsb macro,
resulting in potentially more efficient code. Currently the option is
ignored until all callers are updated (unlike ARM, the option is
mandated by the assembler).
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Somehow SERROR has acquired an additional 'R' in a couple of headers.
This patch removes them before they spread further. As neither instance
is in use yet, no other sites need to be fixed up.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add DSB after icache flush to complete the cache maintenance operation.
The function __flush_icache_all() is used only for user space mappings
and an ISB is not required because of an exception return before executing
user instructions. An exception return would behave like an ISB.
Signed-off-by: Vinayak Kale <vkale@apm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
- Introduction of PTE_WRITE to distinguish between writable but clean
and truly read-only pages
- FIQs enabling/disabling clean-up (they aren't used on arm64)
- CPU resume fix for the per-cpu offset restoring
- Code comment typos
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pyll ARM64 patches from Catalin Marinas:
- Build fix with DMA_CMA enabled
- Introduction of PTE_WRITE to distinguish between writable but clean
and truly read-only pages
- FIQs enabling/disabling clean-up (they aren't used on arm64)
- CPU resume fix for the per-cpu offset restoring
- Code comment typos
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: mm: Introduce PTE_WRITE
arm64: mm: Remove PTE_BIT_FUNC macro
arm64: FIQs are unused
arm64: mm: fix the function name in comment of cpu_do_switch_mm
arm64: fix build error if DMA_CMA is enabled
arm64: kernel: fix per-cpu offset restore on resume
arm64: mm: fix the function name in comment of __flush_dcache_area
arm64: mm: use ubfm for dcache_line_size
We have the following means for encoding writable or dirty ptes:
PTE_DIRTY PTE_RDONLY
!pte_dirty && !pte_write 0 1
!pte_dirty && pte_write 0 1
pte_dirty && !pte_write 1 1
pte_dirty && pte_write 1 0
So we can't distinguish between writable clean ptes and read only
ptes. This can cause problems with ptes being incorrectly flagged as
read only when they are writable but not dirty.
This patch introduces a new software bit PTE_WRITE which allows us to
correctly identify writable ptes. PTE_RDONLY is now only clear for
valid ptes where a page is both writable and dirty.
Signed-off-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Expand out the pte manipulation functions. This makes our life easier
when using things like tags and cscope.
Signed-off-by: Steve Capper <steve.capper@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64/include/asm/dma-contiguous.h is trying to include
<asm-genric/dma-contiguous.h> which does not exist, and thus failing
build for arm64 if we enable CONFIG_DMA_CMA. This patch fixes build
error by removing unwanted header inclusion from arm64's dma-contiguous.h.
Signed-off-by: Pankaj Dubey <pankaj.dubey@samsung.com>
Signed-off-by: Somraj Mani <somraj.mani@samsung.com>
Acked-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Pull networking updates from David Miller:
1) BPF debugger and asm tool by Daniel Borkmann.
2) Speed up create/bind in AF_PACKET, also from Daniel Borkmann.
3) Correct reciprocal_divide and update users, from Hannes Frederic
Sowa and Daniel Borkmann.
4) Currently we only have a "set" operation for the hw timestamp socket
ioctl, add a "get" operation to match. From Ben Hutchings.
5) Add better trace events for debugging driver datapath problems, also
from Ben Hutchings.
6) Implement auto corking in TCP, from Eric Dumazet. Basically, if we
have a small send and a previous packet is already in the qdisc or
device queue, defer until TX completion or we get more data.
7) Allow userspace to manage ipv6 temporary addresses, from Jiri Pirko.
8) Add a qdisc bypass option for AF_PACKET sockets, from Daniel
Borkmann.
9) Share IP header compression code between Bluetooth and IEEE802154
layers, from Jukka Rissanen.
10) Fix ipv6 router reachability probing, from Jiri Benc.
11) Allow packets to be captured on macvtap devices, from Vlad Yasevich.
12) Support tunneling in GRO layer, from Jerry Chu.
13) Allow bonding to be configured fully using netlink, from Scott
Feldman.
14) Allow AF_PACKET users to obtain the VLAN TPID, just like they can
already get the TCI. From Atzm Watanabe.
15) New "Heavy Hitter" qdisc, from Terry Lam.
16) Significantly improve the IPSEC support in pktgen, from Fan Du.
17) Allow ipv4 tunnels to cache routes, just like sockets. From Tom
Herbert.
18) Add Proportional Integral Enhanced packet scheduler, from Vijay
Subramanian.
19) Allow openvswitch to mmap'd netlink, from Thomas Graf.
20) Key TCP metrics blobs also by source address, not just destination
address. From Christoph Paasch.
21) Support 10G in generic phylib. From Andy Fleming.
22) Try to short-circuit GRO flow compares using device provided RX
hash, if provided. From Tom Herbert.
The wireless and netfilter folks have been busy little bees too.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2064 commits)
net/cxgb4: Fix referencing freed adapter
ipv6: reallocate addrconf router for ipv6 address when lo device up
fib_frontend: fix possible NULL pointer dereference
rtnetlink: remove IFLA_BOND_SLAVE definition
rtnetlink: remove check for fill_slave_info in rtnl_have_link_slave_info
qlcnic: update version to 5.3.55
qlcnic: Enhance logic to calculate msix vectors.
qlcnic: Refactor interrupt coalescing code for all adapters.
qlcnic: Update poll controller code path
qlcnic: Interrupt code cleanup
qlcnic: Enhance Tx timeout debugging.
qlcnic: Use bool for rx_mac_learn.
bonding: fix u64 division
rtnetlink: add missing IFLA_BOND_AD_INFO_UNSPEC
sfc: Use the correct maximum TX DMA ring size for SFC9100
Add Shradha Shah as the sfc driver maintainer.
net/vxlan: Share RX skb de-marking and checksum checks with ovs
tulip: cleanup by using ARRAY_SIZE()
ip_tunnel: clear IPCB in ip_tunnel_xmit() in case dst_link_failure() is called
net/cxgb4: Don't retrieve stats during recovery
...
Nothing major here, just bugfixes all over the place. The most
interesting part is the ARM guys' virtualized interrupt controller
overhaul, which lets userspace get/set the state and thus enables
migration of ARM VMs.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM updates from Paolo Bonzini:
"First round of KVM updates for 3.14; PPC parts will come next week.
Nothing major here, just bugfixes all over the place. The most
interesting part is the ARM guys' virtualized interrupt controller
overhaul, which lets userspace get/set the state and thus enables
migration of ARM VMs"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (67 commits)
kvm: make KVM_MMU_AUDIT help text more readable
KVM: s390: Fix memory access error detection
KVM: nVMX: Update guest activity state field on L2 exits
KVM: nVMX: Fix nested_run_pending on activity state HLT
KVM: nVMX: Clean up handling of VMX-related MSRs
KVM: nVMX: Add tracepoints for nested_vmexit and nested_vmexit_inject
KVM: nVMX: Pass vmexit parameters to nested_vmx_vmexit
KVM: nVMX: Leave VMX mode on clearing of feature control MSR
KVM: VMX: Fix DR6 update on #DB exception
KVM: SVM: Fix reading of DR6
KVM: x86: Sync DR7 on KVM_SET_DEBUGREGS
add support for Hyper-V reference time counter
KVM: remove useless write to vcpu->hv_clock.tsc_timestamp
KVM: x86: fix tsc catchup issue with tsc scaling
KVM: x86: limit PIT timer frequency
KVM: x86: handle invalid root_hpa everywhere
kvm: Provide kvm_vcpu_eligible_for_directed_yield() stub
kvm: vfio: silence GCC warning
KVM: ARM: Remove duplicate include
arm/arm64: KVM: relax the requirements of VMA alignment for THP
...
Interface)
- Jump label support
- CMA can now be enabled on arm64
- HWCAP bits for crypto and CRC32 extensions
- Optimised percpu using tpidr_el1 register
- Code cleanup
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull ARM64 updates from Catalin Marinas:
- CPU suspend support on top of PSCI (firmware Power State Coordination
Interface)
- jump label support
- CMA can now be enabled on arm64
- HWCAP bits for crypto and CRC32 extensions
- optimised percpu using tpidr_el1 register
- code cleanup
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (42 commits)
arm64: fix typo in entry.S
arm64: kernel: restore HW breakpoint registers in cpu_suspend
jump_label: use defined macros instead of hard-coding for better readability
arm64, jump label: optimize jump label implementation
arm64, jump label: detect %c support for ARM64
arm64: introduce aarch64_insn_gen_{nop|branch_imm}() helper functions
arm64: move encode_insn_immediate() from module.c to insn.c
arm64: introduce interfaces to hotpatch kernel and module code
arm64: introduce basic aarch64 instruction decoding helpers
arm64: dts: Reduce size of virtio block device for foundation model
arm64: Remove unused __data_loc variable
arm64: Enable CMA
arm64: Warn on NULL device structure for dma APIs
arm64: Add hwcaps for crypto and CRC32 extensions.
arm64: drop redundant macros from read_cpuid()
arm64: Remove outdated comment
arm64: cmpxchg: update macros to prevent warnings
arm64: support single-step and breakpoint handler hooks
ARM64: fix framepointer check in unwind_frame
ARM64: check stack pointer in get_wchan
...
Pull core locking changes from Ingo Molnar:
- futex performance increases: larger hashes, smarter wakeups
- mutex debugging improvements
- lots of SMP ordering documentation updates
- introduce the smp_load_acquire(), smp_store_release() primitives.
(There are WIP patches that make use of them - not yet merged)
- lockdep micro-optimizations
- lockdep improvement: better cover IRQ contexts
- liblockdep at last. We'll continue to monitor how useful this is
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
futexes: Fix futex_hashsize initialization
arch: Re-sort some Kbuild files to hopefully help avoid some conflicts
futexes: Avoid taking the hb->lock if there's nothing to wake up
futexes: Document multiprocessor ordering guarantees
futexes: Increase hash table size for better performance
futexes: Clean up various details
arch: Introduce smp_load_acquire(), smp_store_release()
arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h
arch: Move smp_mb__{before,after}_atomic_{inc,dec}.h into asm/atomic.h
locking/doc: Rename LOCK/UNLOCK to ACQUIRE/RELEASE
mutexes: Give more informative mutex warning in the !lock->owner case
powerpc: Full barrier for smp_mb__after_unlock_lock()
rcu: Apply smp_mb__after_unlock_lock() to preserve grace periods
Documentation/memory-barriers.txt: Downgrade UNLOCK+BLOCK
locking: Add an smp_mb__after_unlock_lock() for UNLOCK+BLOCK barrier
Documentation/memory-barriers.txt: Document ACCESS_ONCE()
Documentation/memory-barriers.txt: Prohibit speculative writes
Documentation/memory-barriers.txt: Add long atomic examples to memory-barriers.txt
Documentation/memory-barriers.txt: Add needed ACCESS_ONCE() calls to memory-barriers.txt
Revert "smp/cpumask: Make CONFIG_CPUMASK_OFFSTACK=y usable without debug dependency"
...
Conflicts:
drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
net/ipv4/tcp_metrics.c
Overlapping changes between the "don't create two tcp metrics objects
with the same key" race fix in net and the addition of the destination
address in the lookup key in net-next.
Minor overlapping changes in bnx2x driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 2f7dc60275.
The above commit breaks the mapping type for Device memory because
pgprot_default already contains a Normal memory type. pgprot_default is
also not initialised early enough for earlyprintk resulting in an
inconsistent memory mapping with 64K PAGE_SIZE configuration.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Will Deacon <will.deacon@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
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Merge tag 'v3.13-rc8' into core/locking
Refresh the tree with the latest fixes, before applying new changes.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A number of situations currently require the heavyweight smp_mb(),
even though there is no need to order prior stores against later
loads. Many architectures have much cheaper ways to handle these
situations, but the Linux kernel currently has no portable way
to make use of them.
This commit therefore supplies smp_load_acquire() and
smp_store_release() to remedy this situation. The new
smp_load_acquire() primitive orders the specified load against
any subsequent reads or writes, while the new smp_store_release()
primitive orders the specifed store against any prior reads or
writes. These primitives allow array-based circular FIFOs to be
implemented without an smp_mb(), and also allow a theoretical
hole in rcu_assign_pointer() to be closed at no additional
expense on most architectures.
In addition, the RCU experience transitioning from explicit
smp_read_barrier_depends() and smp_wmb() to rcu_dereference()
and rcu_assign_pointer(), respectively resulted in substantial
improvements in readability. It therefore seems likely that
replacing other explicit barriers with smp_load_acquire() and
smp_store_release() will provide similar benefits. It appears
that roughly half of the explicit barriers in core kernel code
might be so replaced.
[Changelog by PaulMck]
Reviewed-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Victor Kaplansky <VICTORK@il.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/20131213150640.908486364@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Introduce aarch64_insn_gen_{nop|branch_imm}() helper functions, which
will be used to implement jump label on ARM64.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Function encode_insn_immediate() will be used by other instruction
manipulate related functions, so move it into insn.c and rename it
as aarch64_insn_encode_immediate().
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Introduce three interfaces to patch kernel and module code:
aarch64_insn_patch_text_nosync():
patch code without synchronization, it's caller's responsibility
to synchronize all CPUs if needed.
aarch64_insn_patch_text_sync():
patch code and always synchronize with stop_machine()
aarch64_insn_patch_text():
patch code and synchronize with stop_machine() if needed
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Conflicts:
drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c
net/ipv6/ip6_tunnel.c
net/ipv6/ip6_vti.c
ipv6 tunnel statistic bug fixes conflicting with consolidation into
generic sw per-cpu net stats.
qlogic conflict between queue counting bug fix and the addition
of multiple MAC address support.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows us to have X-Gene guest VCPU when using KVM arm64
on APM X-Gene host.
We add KVM_ARM_TARGET_XGENE_POTENZA for X-Gene Potenza compatible
guest VCPU and we return KVM_ARM_TARGET_XGENE_POTENZA in kvm_target_cpu()
when running on X-Gene host with Potenza core.
[maz: sanitized the commit log]
Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Current max VCPUs per-Guest is set to 4 which is preventing
us from creating a Guest (or VM) with 8 VCPUs on Host (e.g.
X-Gene Storm SOC) with 8 Host CPUs.
The correct value of max VCPUs per-Guest should be same as
the max CPUs supported by GICv2 which is 8 but, increasing
value of max VCPUs per-Guest can make things slower hence
we add Kconfig option to let KVM users select appropriate
max VCPUs per-Guest.
Signed-off-by: Anup Patel <anup.patel@linaro.org>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
For migration to work we need to save (and later restore) the state of
each core's virtual generic timer.
Since this is per VCPU, we can use the [gs]et_one_reg ioctl and export
the three needed registers (control, counter, compare value).
Though they live in cp15 space, we don't use the existing list, since
they need special accessor functions and the arch timer is optional.
Acked-by: Marc Zynger <marc.zyngier@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
- Fix balloon driver for auto-translate guests (PVHVM, ARM) to not use
scratch pages.
- Fix block API header for ARM32 and ARM64 to have proper layout
- On ARM when mapping guests, stick on PTE_SPECIAL
- When using SWIOTLB under ARM, don't call swiotlb functions twice
- When unmapping guests memory and if we fail, don't return pages which
failed to be unmapped.
- Grant driver was using the wrong address on ARM.
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Merge tag 'stable/for-linus-3.13-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen bugfixes from Konrad Rzeszutek Wilk:
- Fix balloon driver for auto-translate guests (PVHVM, ARM) to not use
scratch pages.
- Fix block API header for ARM32 and ARM64 to have proper layout
- On ARM when mapping guests, stick on PTE_SPECIAL
- When using SWIOTLB under ARM, don't call swiotlb functions twice
- When unmapping guests memory and if we fail, don't return pages which
failed to be unmapped.
- Grant driver was using the wrong address on ARM.
* tag 'stable/for-linus-3.13-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/balloon: Seperate the auto-translate logic properly (v2)
xen/block: Correctly define structures in public headers on ARM32 and ARM64
arm: xen: foreign mapping PTEs are special.
xen/arm64: do not call the swiotlb functions twice
xen: privcmd: do not return pages which we have failed to unmap
XEN: Grant table address, xen_hvm_resume_frames, is a phys_addr not a pfn
arm64 bit targets need the features CMA provides. Add the appropriate
hooks, header files, and Kconfig to allow this to happen.
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Advertise the optional cryptographic and CRC32 instructions to
user space where present. Several hwcap bits [3-7] are allocated.
Signed-off-by: Steve Capper <steve.capper@linaro.org>
[bit 2 is taken now so use bits 3-7 instead]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
asm/cputype.h contains a bunch of #defines for CPU id registers
that essentially map to themselves. Remove the #defines and pass
the tokens directly to the inline asm() that reads the registers.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Make sure the value we are going to return is referenced in order to
avoid warnings from newer GCCs such as:
arch/arm64/include/asm/cmpxchg.h:162:3: warning: value computed is not used [-Wunused-value]
((__typeof__(*(ptr)))__cmpxchg_mb((ptr), \
^
net/netfilter/nf_conntrack_core.c:674:2: note: in expansion of macro ‘cmpxchg’
cmpxchg(&nf_conntrack_hash_rnd, 0, rand);
[Modified to use the current underlying implementation as current
mainline for both cmpxchg() and cmpxchg_local() does -- broonie]
Signed-off-by: Mark Hambleton <mahamble@broadcom.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
AArch64 Single Steping and Breakpoint debug exceptions will be
used by multiple debug framworks like kprobes & kgdb.
This patch implements the hooks for those frameworks to register
their own handlers for handling breakpoint and single step events.
Reworked the debug exception handler in entry.S: do_dbg to route
software breakpoint (BRK64) exception to do_debug_exception()
Signed-off-by: Sandeepa Prabhu <sandeepa.prabhu@linaro.org>
Signed-off-by: Deepak Saxena <dsaxena@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
DCACHE_WORD_ACCESS uses the word-at-a-time API for optimised string
comparisons in the vfs layer.
This patch implements support for load_unaligned_zeropad in much the
same way as has been done for ARM, although big-endian systems are also
supported.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
AArch64 instructions must be 4-byte aligned, so make sure this is true
for the futex .fixup section.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch implements the word-at-a-time interface for arm64 using the
same algorithm as ARM. We use the fls64 macro, which expands to a clz
instruction via a compiler builtin. Big-endian configurations make use
of the implementation from asm-generic.
With this implemented, we can replace our byte-at-a-time strnlen_user
and strncpy_from_user functions with the optimised generic versions.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch implements optimised percpu variable accesses using the
el1 r/w thread register (tpidr_el1) along the same lines as arch/arm/.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The definition of virt_addr_valid is that virt_addr_valid should
return true if and only if virt_to_page returns a valid pointer.
The current definition of virt_addr_valid only checks against the
virtual address range. There's no guarantee that just because a
virtual address falls bewteen PAGE_OFFSET and high_memory the
associated physical memory has a valid backing struct page. Follow
the example of other architectures and convert to pfn_valid to
verify that the virtual address is actually valid.
Cc: Will Deacon <will.deacon@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Conflicts:
drivers/net/ethernet/intel/i40e/i40e_main.c
drivers/net/macvtap.c
Both minor merge hassles, simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
On platforms with power management capabilities, timers that are shut
down when a CPU enters deep C-states must be emulated using an always-on
timer and a timer IPI to relay the timer IRQ to target CPUs on an SMP
system.
This patch enables the generic clockevents broadcast infrastructure for
arm64, by providing the required Kconfig entries and adding the timer
IPI infrastructure.
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Kernel subsystems like CPU idle and suspend to RAM require a generic
mechanism to suspend a processor, save its context and put it into
a quiescent state. The cpu_{suspend}/{resume} implementation provides
such a framework through a kernel interface allowing to save/restore
registers, flush the context to DRAM and suspend/resume to/from
low-power states where processor context may be lost.
The CPU suspend implementation relies on the suspend protocol registered
in CPU operations to carry out a suspend request after context is
saved and flushed to DRAM. The cpu_suspend interface:
int cpu_suspend(unsigned long arg);
allows to pass an opaque parameter that is handed over to the suspend CPU
operations back-end so that it can take action according to the
semantics attached to it. The arg parameter allows suspend to RAM and CPU
idle drivers to communicate to suspend protocol back-ends; it requires
standardization so that the interface can be reused seamlessly across
systems, paving the way for generic drivers.
Context memory is allocated on the stack, whose address is stashed in a
per-cpu variable to keep track of it and passed to core functions that
save/restore the registers required by the architecture.
Even though, upon successful execution, the cpu_suspend function shuts
down the suspending processor, the warm boot resume mechanism, based
on the cpu_resume function, makes the resume path operate as a
cpu_suspend function return, so that cpu_suspend can be treated as a C
function by the caller, which simplifies coding the PM drivers that rely
on the cpu_suspend API.
Upon context save, the minimal amount of memory is flushed to DRAM so
that it can be retrieved when the MMU is off and caches are not searched.
The suspend CPU operation, depending on the required operations (eg CPU vs
Cluster shutdown) is in charge of flushing the cache hierarchy either
implicitly (by calling firmware implementations like PSCI) or explicitly
by executing the required cache maintainance functions.
Debug exceptions are disabled during cpu_{suspend}/{resume} operations
so that debug registers can be saved and restored properly preventing
preemption from debug agents enabled in the kernel.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Power management software requires the kernel to save and restore
CPU registers while going through suspend and resume operations
triggered by kernel subsystems like CPU idle and suspend to RAM.
This patch implements code that provides save and restore mechanism
for the arm v8 implementation. Memory for the context is passed as
parameter to both cpu_do_suspend and cpu_do_resume functions, and allows
the callers to implement context allocation as they deem fit.
The registers that are saved and restored correspond to the registers set
actually required by the kernel to be up and running which represents a
subset of v8 ISA.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
On ARM64 SMP systems, cores are identified by their MPIDR_EL1 register.
The MPIDR_EL1 guidelines in the ARM ARM do not provide strict enforcement of
MPIDR_EL1 layout, only recommendations that, if followed, split the MPIDR_EL1
on ARM 64 bit platforms in four affinity levels. In multi-cluster
systems like big.LITTLE, if the affinity guidelines are followed, the
MPIDR_EL1 can not be considered a linear index. This means that the
association between logical CPU in the kernel and the HW CPU identifier
becomes somewhat more complicated requiring methods like hashing to
associate a given MPIDR_EL1 to a CPU logical index, in order for the look-up
to be carried out in an efficient and scalable way.
This patch provides a function in the kernel that starting from the
cpu_logical_map, implement collision-free hashing of MPIDR_EL1 values by
checking all significative bits of MPIDR_EL1 affinity level bitfields.
The hashing can then be carried out through bits shifting and ORing; the
resulting hash algorithm is a collision-free though not minimal hash that can
be executed with few assembly instructions. The mpidr_el1 is filtered through a
mpidr mask that is built by checking all bits that toggle in the set of
MPIDR_EL1s corresponding to possible CPUs. Bits that do not toggle do not
carry information so they do not contribute to the resulting hash.
Pseudo code:
/* check all bits that toggle, so they are required */
for (i = 1, mpidr_el1_mask = 0; i < num_possible_cpus(); i++)
mpidr_el1_mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
/*
* Build shifts to be applied to aff0, aff1, aff2, aff3 values to hash the
* mpidr_el1
* fls() returns the last bit set in a word, 0 if none
* ffs() returns the first bit set in a word, 0 if none
*/
fs0 = mpidr_el1_mask[7:0] ? ffs(mpidr_el1_mask[7:0]) - 1 : 0;
fs1 = mpidr_el1_mask[15:8] ? ffs(mpidr_el1_mask[15:8]) - 1 : 0;
fs2 = mpidr_el1_mask[23:16] ? ffs(mpidr_el1_mask[23:16]) - 1 : 0;
fs3 = mpidr_el1_mask[39:32] ? ffs(mpidr_el1_mask[39:32]) - 1 : 0;
ls0 = fls(mpidr_el1_mask[7:0]);
ls1 = fls(mpidr_el1_mask[15:8]);
ls2 = fls(mpidr_el1_mask[23:16]);
ls3 = fls(mpidr_el1_mask[39:32]);
bits0 = ls0 - fs0;
bits1 = ls1 - fs1;
bits2 = ls2 - fs2;
bits3 = ls3 - fs3;
aff0_shift = fs0;
aff1_shift = 8 + fs1 - bits0;
aff2_shift = 16 + fs2 - (bits0 + bits1);
aff3_shift = 32 + fs3 - (bits0 + bits1 + bits2);
u32 hash(u64 mpidr_el1) {
u32 l[4];
u64 mpidr_el1_masked = mpidr_el1 & mpidr_el1_mask;
l[0] = mpidr_el1_masked & 0xff;
l[1] = mpidr_el1_masked & 0xff00;
l[2] = mpidr_el1_masked & 0xff0000;
l[3] = mpidr_el1_masked & 0xff00000000;
return (l[0] >> aff0_shift | l[1] >> aff1_shift | l[2] >> aff2_shift |
l[3] >> aff3_shift);
}
The hashing algorithm relies on the inherent properties set in the ARM ARM
recommendations for the MPIDR_EL1. Exotic configurations, where for instance
the MPIDR_EL1 values at a given affinity level have large holes, can end up
requiring big hash tables since the compression of values that can be achieved
through shifting is somewhat crippled when holes are present. Kernel warns if
the number of buckets of the resulting hash table exceeds the number of
possible CPUs by a factor of 4, which is a symptom of a very sparse HW
MPIDR_EL1 configuration.
The hash algorithm is quite simple and can easily be implemented in assembly
code, to be used in code paths where the kernel virtual address space is
not set-up (ie cpu_resume) and instruction and data fetches are strongly
ordered so code must be compact and must carry out few data accesses.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
In order to simplify access to different affinity levels within the
MPIDR_EL1 register values, this patch implements some preprocessor
macros that allow to retrieve the MPIDR_EL1 affinity level value according
to the level passed as input parameter.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
KVM initialisation fails on architectures implementing virt_to_idmap()
because virt_to_phys() on such architectures won't fetch you the correct
idmap page.
So update the KVM ARM code to use the virt_to_idmap() to fix the issue.
Since the KVM code is shared between arm and arm64, we create
kvm_virt_to_phys() and handle the redirection in respective headers.
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
