Based on include/xen/mm.h [1], Linux is mistakenly using MFN when GFN
is meant, I suspect this is because the first support for Xen was for
PV. This resulted in some misimplementation of helpers on ARM and
confused developers about the expected behavior.
For instance, with pfn_to_mfn, we expect to get an MFN based on the name.
Although, if we look at the implementation on x86, it's returning a GFN.
For clarity and avoid new confusion, replace any reference to mfn with
gfn in any helpers used by PV drivers. The x86 code will still keep some
reference of pfn_to_mfn which may be used by all kind of guests
No changes as been made in the hypercall field, even
though they may be invalid, in order to keep the same as the defintion
in xen repo.
Note that page_to_mfn has been renamed to xen_page_to_gfn to avoid a
name to close to the KVM function gfn_to_page.
Take also the opportunity to simplify simple construction such
as pfn_to_mfn(page_to_pfn(page)) into xen_page_to_gfn. More complex clean up
will come in follow-up patches.
[1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commitdiff;h=e758ed14f390342513405dd766e874934573e6cb
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
After the commit introducing convertion between DMA and guest addresses,
all the callers of pfn_to_mfn are expecting to get a GFN (Guest Frame
Number). On ARM, all the guests are auto-translated so the GFN is equal
to the Linux PFN (Pseudo-physical Frame Number).
The current implementation may return an MFN if the caller is passing a
PFN associated to a mapped foreign grant. In pratice, I haven't seen
the problem on running guest but we should fix it for the sake of
correctness.
Correct the implementation by always returning the pfn passed in parameter.
A follow-up patch will take care to rename pfn_to_mfn to a suitable
name.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
The swiotlb is required when programming a DMA address on ARM when a
device is not protected by an IOMMU.
In this case, the DMA address should always be equal to the machine address.
For DOM0 memory, Xen ensure it by have an identity mapping between the
guest address and host address. However, when mapping a foreign grant
reference, the 1:1 model doesn't work.
For ARM guest, most of the callers of pfn_to_mfn expects to get a GFN
(Guest Frame Number), i.e a PFN (Page Frame Number) from the Linux point
of view given that all ARM guest are auto-translated.
Even though the name pfn_to_mfn is misleading, we need to ensure that
those caller get a GFN and not by mistake a MFN. In pratical, I haven't
seen error related to this but we should fix it for the sake of
correctness.
In order to fix the implementation of pfn_to_mfn on ARM in a follow-up
patch, we have to introduce new helpers to return the DMA from a PFN and
the invert.
On x86, the new helpers will be an alias of pfn_to_mfn and mfn_to_pfn.
The helpers will be used in swiotlb and xen_biovec_phys_mergeable.
This is necessary in the latter because we have to ensure that the
biovec code will not try to merge a biovec using foreign page and
another using Linux memory.
Lastly, the helper mfn_to_local_pfn has been renamed to bfn_to_local_pfn
given that the only usage was in swiotlb.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Pull ARM development updates from Russell King:
"Included in this update:
- moving PSCI code from ARM64/ARM to drivers/
- removal of some architecture internals from global kernel view
- addition of software based "privileged no access" support using the
old domains register to turn off the ability for kernel
loads/stores to access userspace. Only the proper accessors will
be usable.
- addition of early fixup support for early console
- re-addition (and reimplementation) of OMAP special interconnect
barrier
- removal of finish_arch_switch()
- only expose cpuX/online in sysfs if hotpluggable
- a number of code cleanups"
* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (41 commits)
ARM: software-based priviledged-no-access support
ARM: entry: provide uaccess assembly macro hooks
ARM: entry: get rid of multiple macro definitions
ARM: 8421/1: smp: Collapse arch_cpu_idle_dead() into cpu_die()
ARM: uaccess: provide uaccess_save_and_enable() and uaccess_restore()
ARM: mm: improve do_ldrd_abort macro
ARM: entry: ensure that IRQs are enabled when calling syscall_trace_exit()
ARM: entry: efficiency cleanups
ARM: entry: get rid of asm_trace_hardirqs_on_cond
ARM: uaccess: simplify user access assembly
ARM: domains: remove DOMAIN_TABLE
ARM: domains: keep vectors in separate domain
ARM: domains: get rid of manager mode for user domain
ARM: domains: move initial domain setting value to asm/domains.h
ARM: domains: provide domain_mask()
ARM: domains: switch to keeping domain value in register
ARM: 8419/1: dma-mapping: harmonize definition of DMA_ERROR_CODE
ARM: 8417/1: refactor bitops functions with BIT_MASK() and BIT_WORD()
ARM: 8416/1: Feroceon: use of_iomap() to map register base
ARM: 8415/1: early fixmap support for earlycon
...
Pull locking and atomic updates from Ingo Molnar:
"Main changes in this cycle are:
- Extend atomic primitives with coherent logic op primitives
(atomic_{or,and,xor}()) and deprecate the old partial APIs
(atomic_{set,clear}_mask())
The old ops were incoherent with incompatible signatures across
architectures and with incomplete support. Now every architecture
supports the primitives consistently (by Peter Zijlstra)
- Generic support for 'relaxed atomics':
- _acquire/release/relaxed() flavours of xchg(), cmpxchg() and {add,sub}_return()
- atomic_read_acquire()
- atomic_set_release()
This came out of porting qwrlock code to arm64 (by Will Deacon)
- Clean up the fragile static_key APIs that were causing repeat bugs,
by introducing a new one:
DEFINE_STATIC_KEY_TRUE(name);
DEFINE_STATIC_KEY_FALSE(name);
which define a key of different types with an initial true/false
value.
Then allow:
static_branch_likely()
static_branch_unlikely()
to take a key of either type and emit the right instruction for the
case. To be able to know the 'type' of the static key we encode it
in the jump entry (by Peter Zijlstra)
- Static key self-tests (by Jason Baron)
- qrwlock optimizations (by Waiman Long)
- small futex enhancements (by Davidlohr Bueso)
- ... and misc other changes"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
jump_label/x86: Work around asm build bug on older/backported GCCs
locking, ARM, atomics: Define our SMP atomics in terms of _relaxed() operations
locking, include/llist: Use linux/atomic.h instead of asm/cmpxchg.h
locking/qrwlock: Make use of _{acquire|release|relaxed}() atomics
locking/qrwlock: Implement queue_write_unlock() using smp_store_release()
locking/lockref: Remove homebrew cmpxchg64_relaxed() macro definition
locking, asm-generic: Add _{relaxed|acquire|release}() variants for 'atomic_long_t'
locking, asm-generic: Rework atomic-long.h to avoid bulk code duplication
locking/atomics: Add _{acquire|release|relaxed}() variants of some atomic operations
locking, compiler.h: Cast away attributes in the WRITE_ONCE() magic
locking/static_keys: Make verify_keys() static
jump label, locking/static_keys: Update docs
locking/static_keys: Provide a selftest
jump_label: Provide a self-test
s390/uaccess, locking/static_keys: employ static_branch_likely()
x86, tsc, locking/static_keys: Employ static_branch_likely()
locking/static_keys: Add selftest
locking/static_keys: Add a new static_key interface
locking/static_keys: Rework update logic
locking/static_keys: Add static_key_{en,dis}able() helpers
...
Pull ARM SoC platform updates from Olof Johansson:
"New or improved SoC support:
- add support for Atmel's SAMA5D2 SoC
- add support for Freescale i.MX6UL
- improved support for TI's DM814x platform
- misc fixes and improvements for RockChip platforms
- Marvell MVEBU suspend/resume support
A few driver changes that ideally would belong in the drivers branch
are also here (acked by appropriate maintainers):
- power key input driver for Freescale platforms (svns)
- RTC driver updates for Freescale platforms (svns/mxc)
- clk fixes for TI DM814/816X
+ a bunch of other changes for various platforms"
* tag 'armsoc-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (83 commits)
ARM: rockchip: pm: Fix PTR_ERR() argument
ARM: imx: mach-imx6ul: Fix allmodconfig build
clk: ti: fix for definition movement
ARM: uniphier: drop v7_invalidate_l1 call at secondary entry
memory: kill off set_irq_flags usage
rtc: snvs: select option REGMAP_MMIO
ARM: brcmstb: select ARCH_DMA_ADDR_T_64BIT for LPAE
ARM: BCM: Enable ARM erratum 798181 for BRCMSTB
ARM: OMAP2+: Fix power domain operations regression caused by 81xx
ARM: rockchip: enable PMU_GPIOINT_WAKEUP_EN when entering shallow suspend
ARM: rockchip: set correct stabilization thresholds in suspend
ARM: rockchip: rename osc_switch_to_32k variable
ARM: imx6ul: add fec MAC refrence clock and phy fixup init
ARM: imx6ul: add fec bits to GPR syscon definition
rtc: mxc: add support of device tree
dt-binding: document the binding for mxc rtc
rtc: mxc: use a second rtc clock
ARM: davinci: cp_intc: use IRQCHIP_SKIP_SET_WAKE instead of irq_set_wake callback
soc: mediatek: Fix SCPSYS compilation
ARM: at91/soc: add basic support for new sama5d2 SoC
...
Pull scheduler updates from Ingo Molnar:
"The biggest change in this cycle is the rewrite of the main SMP load
balancing metric: the CPU load/utilization. The main goal was to make
the metric more precise and more representative - see the changelog of
this commit for the gory details:
9d89c257df ("sched/fair: Rewrite runnable load and utilization average tracking")
It is done in a way that significantly reduces complexity of the code:
5 files changed, 249 insertions(+), 494 deletions(-)
and the performance testing results are encouraging. Nevertheless we
need to keep an eye on potential regressions, since this potentially
affects every SMP workload in existence.
This work comes from Yuyang Du.
Other changes:
- SCHED_DL updates. (Andrea Parri)
- Simplify architecture callbacks by removing finish_arch_switch().
(Peter Zijlstra et al)
- cputime accounting: guarantee stime + utime == rtime. (Peter
Zijlstra)
- optimize idle CPU wakeups some more - inspired by Facebook server
loads. (Mike Galbraith)
- stop_machine fixes and updates. (Oleg Nesterov)
- Introduce the 'trace_sched_waking' tracepoint. (Peter Zijlstra)
- sched/numa tweaks. (Srikar Dronamraju)
- misc fixes and small cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
sched/deadline: Fix comment in enqueue_task_dl()
sched/deadline: Fix comment in push_dl_tasks()
sched: Change the sched_class::set_cpus_allowed() calling context
sched: Make sched_class::set_cpus_allowed() unconditional
sched: Fix a race between __kthread_bind() and sched_setaffinity()
sched: Ensure a task has a non-normalized vruntime when returning back to CFS
sched/numa: Fix NUMA_DIRECT topology identification
tile: Reorganize _switch_to()
sched, sparc32: Update scheduler comments in copy_thread()
sched: Remove finish_arch_switch()
sched, tile: Remove finish_arch_switch
sched, sh: Fold finish_arch_switch() into switch_to()
sched, score: Remove finish_arch_switch()
sched, avr32: Remove finish_arch_switch()
sched, MIPS: Get rid of finish_arch_switch()
sched, arm: Remove finish_arch_switch()
sched/fair: Clean up load average references
sched/fair: Provide runnable_load_avg back to cfs_rq
sched/fair: Remove task and group entity load when they are dead
sched/fair: Init cfs_rq's sched_entity load average
...
Three architectures already define these, and we'll need them genericly
soon.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Provide a software-based implementation of the priviledged no access
support found in ARMv8.1.
Userspace pages are mapped using a different domain number from the
kernel and IO mappings. If we switch the user domain to "no access"
when we enter the kernel, we can prevent the kernel from touching
userspace.
However, the kernel needs to be able to access userspace via the
various user accessor functions. With the wrapping in the previous
patch, we can temporarily enable access when the kernel needs user
access, and re-disable it afterwards.
This allows us to trap non-intended accesses to userspace, eg, caused
by an inadvertent dereference of the LIST_POISON* values, which, with
appropriate user mappings setup, can be made to succeed. This in turn
can allow use-after-free bugs to be further exploited than would
otherwise be possible.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Provide hooks into the kernel entry and exit paths to permit control
of userspace visibility to the kernel. The intended use is:
- on entry to kernel from user, uaccess_disable will be called to
disable userspace visibility
- on exit from kernel to user, uaccess_enable will be called to
enable userspace visibility
- on entry from a kernel exception, uaccess_save_and_disable will be
called to save the current userspace visibility setting, and disable
access
- on exit from a kernel exception, uaccess_restore will be called to
restore the userspace visibility as it was before the exception
occurred.
These hooks allows us to keep userspace visibility disabled for the
vast majority of the kernel, except for localised regions where we
want to explicitly access userspace.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The only caller of cpu_die() on ARM is arch_cpu_idle_dead(), so
let's simplify the code by renaming cpu_die() to
arch_cpu_idle_dead(). While were here, drop the __ref annotation
because __cpuinit is gone nowadays.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Provide uaccess_save_and_enable() and uaccess_restore() to permit
control of userspace visibility to the kernel, and hook these into
the appropriate places in the kernel where we need to access
userspace.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Make the "fast" syscall return path fast again. The addition of IRQ
tracing and context tracking has made this path grossly inefficient.
We can do much better if these options are enabled if we save the
syscall return code on the stack - we then don't need to save a bunch
of registers around every single callout to C code.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The user assembly for byte and word accesses was virtually identical.
Rather than duplicating this, use a macro instead.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
DOMAIN_TABLE is not used; in any case, it aliases to the kernel domain.
Remove this definition.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Keep the machine vectors in its own domain to avoid software based
user access control from making the vector code inaccessible, and
thereby deadlocking the machine.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since we switched to early trap initialisation in 94e5a85b3b
("ARM: earlier initialization of vectors page") we haven't been writing
directly to the vectors page, and so there's no need for this domain
to be in manager mode. Switch it to client mode.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Provide a macro to generate the mask for a domain, rather than using
domain_val(, DOMAIN_MANAGER) which won't work when CPU_USE_DOMAINS
is turned off.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than modifying both the domain access control register and our
per-thread copy, modify only the domain access control register, and
use the per-thread copy to save and restore the register over context
switches. We can also avoid the explicit initialisation of the
init thread_info structure.
This allows us to avoid needing to gain access to the thread information
at the uaccess control sites.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM now uses pci_bus->msi to store the msi_controller pointer, so we don't
need to save it in struct pci_sys_data, and we don't need to implement
pcibios_msi_controller() to get it out of pci_sys_data.
Remove msi_controller from struct pci_sys_data and
pcibios_msi_controller().
[bhelgaas: changelog, split into separate patch]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jingoo Han <jingoohan1@gmail.com>
ARM previously stored the msi_controller pointer in its sysdata, struct
pci_sys_data, and implemented pcibios_msi_controller() to retrieve it.
That made PCI host controller drivers specific to ARM because they had to
put the msi_controller pointer in the ARM-specific pci_sys_data.
There is now a generic mechanism, pci_scan_root_bus_msi(), for giving the
msi_controller pointer to the PCI core. Use this for all ARM systems and
for the DesignWare and Xilinx PCI host controller drivers.
This removes an ARM dependency from the DesignWare, DRA7xx, EXYNOS, i.MX6,
Keystone, Layerscape, SPEAr13xx, and Xilinx drivers.
[bhelgaas: changelog, split into separate patch]
Suggested-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
CC: Pratyush Anand <pratyush.anand@gmail.com>
CC: Arnd Bergmann <arnd@arndb.de>
CC: Simon Horman <horms@verge.net.au>
CC: Russell King <linux@arm.linux.org.uk>
CC: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Michal Simek <michal.simek@xilinx.com>
CC: Marc Zyngier <marc.zyngier@arm.com>
ARM guests are always HVM. The current implementation is assuming a 1:1
mapping which is only true for DOM0 and may not be at all in the future.
Furthermore, all the helpers but arbitrary_virt_to_machine are used in
x86 specific code (or only compiled for).
The helper arbitrary_virt_to_machine is only used in PV specific code.
Therefore we should never call the function.
Add a BUG() in this helper and drop all the others.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Currently, the event channel rebind code is gated with the presence of
the vector callback.
The virtual interrupt controller on ARM has the concept of per-CPU
interrupt (PPI) which allow us to support per-VCPU event channel.
Therefore there is no need of vector callback for ARM.
Xen is already using a free PPI to notify the guest VCPU of an event.
Furthermore, the xen code initialization in Linux (see
arch/arm/xen/enlighten.c) is requesting correctly a per-CPU IRQ.
Introduce new helper xen_support_evtchn_rebind to allow architecture
decide whether rebind an event is support or not. It will always return
true on ARM and keep the same behavior on x86.
This is also allow us to drop the usage of xen_have_vector_callback
entirely in the ARM code.
Signed-off-by: Julien Grall <julien.grall@citrix.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
The i.MX SoC changes for 4.3:
- Add i.MX6 Ultralite SoC support, which is the newest addition to
i.MX6 family. It integrates a single Cortex-A7 core and a power
management module that reduces the complexity of external power
supply and simplifies power sequencing.
- Change SNVS RTC driver to use syscon interface for register access,
and add SNVS power key driver support.
- Add a second clock for mxc rtc driver, and support device tree probe
for the driver.
- Add FEC MAC reference clock and phy fixup initialization for i.MX6UL
platform.
* tag 'imx-soc-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
rtc: snvs: select option REGMAP_MMIO
ARM: imx6ul: add fec MAC refrence clock and phy fixup init
ARM: imx6ul: add fec bits to GPR syscon definition
rtc: mxc: add support of device tree
dt-binding: document the binding for mxc rtc
rtc: mxc: use a second rtc clock
input: snvs_pwrkey: use "wakeup-source" as deivce tree property name
Document: devicetree: input: imx: i.mx snvs power device tree bindings
input: keyboard: imx: add snvs power key driver
Document: dt: fsl: snvs: change support syscon
rtc: snvs: use syscon to access register
ARM: imx: add low-level debug support for i.mx6ul
ARM: imx: add i.mx6ul msl support
Signed-off-by: Olof Johansson <olof@lixom.net>
All architectures except arm that define DMA_ERROR_CODE are casting it
to (dma_addr_t) - as it is always compared to dma_addr_t in arm as well
this could be harmonized.
Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add early fixmap support, initially to support permanent, fixed
mapping support for early console. A temporary, early pte is
created which is migrated to a permanent mapping in paging_init.
This is also needed since the attributes may change as the memory
types are initialized. The 3MiB range of fixmap spans two pte
tables, but currently only one pte is created for early fixmap
support.
Re-add FIX_KMAP_BEGIN to the index calculation in highmem.c since
the index for kmap does not start at zero anymore. This reverts
4221e2e6b3 ("ARM: 8031/1: fixmap: remove FIX_KMAP_BEGIN and
FIX_KMAP_END") to some extent.
Cc: Mark Salter <msalter@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rathe rthan directly accessing architecture internal functions, provide
an "method"-centric wrapper for qcom_scm-32 to do what's necessary to
ensure that the secure monitor can see the data. This is called
"secure_flush_area" and ensures that the specified memory area is
coherent across the secure boundary.
Acked-by: Andy Gross <agross@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arm: Xilinx Zynq SoC patches for v4.2
- Fix earlyprintk, jump trampoline for SMP
- Update git tree location
- Setup PL310 aux (bit 22)
* tag 'zynq-soc-for-4.3' of https://github.com/Xilinx/linux-xlnx:
ARM: zynq: reserve space for jump target in secondary trampoline
clk: zynq: remove redundant $(CONFIG_ARCH_ZYNQ) in Makefile
MAINTAINERS: Update Zynq git tree location
ARM: zynq: Set bit 22 in PL310 AuxCtrl register (6395/1)
ARM: zynq: Fix earlyprintk in big endian mode
Signed-off-by: Olof Johansson <olof@lixom.net>
Now that the common PSCI client code has been factored out to
drivers/firmware, and made safe for 32-bit use, move the 32-bit ARM code
over to it. This results in a moderate reduction of duplicated lines,
and will prevent further duplication as the PSCI client code is updated
for PSCI 1.0 and beyond.
The two legacy platform users of the PSCI invocation code are updated to
account for interface changes. In both cases the power state parameter
(which is constant) is now generated using macros, so that the
pack/unpack logic can be killed in preparation for PSCI 1.0 power state
changes.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ashwin Chaugule <ashwin.chaugule@linaro.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
There are various problems and short-comings with the current
static_key interface:
- static_key_{true,false}() read like a branch depending on the key
value, instead of the actual likely/unlikely branch depending on
init value.
- static_key_{true,false}() are, as stated above, tied to the
static_key init values STATIC_KEY_INIT_{TRUE,FALSE}.
- we're limited to the 2 (out of 4) possible options that compile to
a default NOP because that's what our arch_static_branch() assembly
emits.
So provide a new static_key interface:
DEFINE_STATIC_KEY_TRUE(name);
DEFINE_STATIC_KEY_FALSE(name);
Which define a key of different types with an initial true/false
value.
Then allow:
static_branch_likely()
static_branch_unlikely()
to take a key of either type and emit the right instruction for the
case.
This means adding a second arch_static_branch_jump() assembly helper
which emits a JMP per default.
In order to determine the right instruction for the right state,
encode the branch type in the LSB of jump_entry::key.
This is the final step in removing the naming confusion that has led to
a stream of avoidable bugs such as:
a833581e37 ("x86, perf: Fix static_key bug in load_mm_cr4()")
... but it also allows new static key combinations that will give us
performance enhancements in the subsequent patches.
Tested-by: Rabin Vincent <rabin@rab.in> # arm
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> # ppc
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # s390
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The dmac_* functions are private to the ARM DMA API implementation, and
should not be used by drivers. In order to discourage their use, remove
their prototypes and macros from asm/*.h.
We have to leave dmac_flush_range() behind as Exynos and MSM IOMMU code
use these; once these sites are fixed, this can be moved also.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fold finish_arch_switch() into switch_to(), in preparation for the
removal of the finish_arch_switch call from core sched code.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Writes to /sys/.../cpuX/online fail if we determine the platform
doesn't support hotplug for that CPU. Furthermore, if the cpu_die
op isn't specified the system hangs when we try to offline a CPU
and it comes right back online unexpectedly. Let's figure this
stuff out before we make the sysfs nodes so that the online file
doesn't even exist if it isn't (at least sometimes) possible to
hotplug the CPU.
Add a new 'cpu_can_disable' op and repoint all 'cpu_disable'
implementations at it because all implementers use the op to
indicate if a CPU can be hotplugged or not in a static fashion.
With PSCI we may need to add a 'cpu_disable' op so that the
secure OS can be migrated off the CPU we're trying to hotplug.
In this case, the 'cpu_can_disable' op will indicate that all
CPUs are hotpluggable by returning true, but the 'cpu_disable' op
will make a PSCI migration call and occasionally fail, denying
the hotplug of a CPU. This shouldn't be any worse than x86 where
we may indicate that all CPUs are hotpluggable but occasionally
we can't offline a CPU due to check_irq_vectors_for_cpu_disable()
failing to find a CPU to move vectors to.
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Cc: Dave Martin <Dave.Martin@arm.com>
Acked-by: Simon Horman <horms@verge.net.au> [shmobile portion]
Tested-by: Simon Horman <horms@verge.net.au>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: <linux-sh@vger.kernel.org>
Tested-by: Tyler Baker <tyler.baker@linaro.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
To enable sharing of the arm_pmu code with arm64, this patch factors it
out to drivers/perf/. A new drivers/perf directory is added for
performance monitor drivers to live under.
MAINTAINERS is updated accordingly. Files added previously without a
corresponsing MAINTAINERS update (perf_regs.c, perf_callchain.c, and
perf_event.h) are also added.
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
[will: augmented Kconfig help slightly]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Implement atomic logic ops -- atomic_{or,xor,and}.
These will replace the atomic_{set,clear}_mask functions that are
available on some archs.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Implement atomic logic ops -- atomic_{or,xor,and}.
These will replace the atomic_{set,clear}_mask functions that are
available on some archs.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Add an extension to the heavy barrier code to allow a SoC specific
memory barrier function to be provided. This is needed for platforms
where the interconnect has weak ordering, and thus needs assistance
to ensure that memory writes are properly visible in the correct order
to other parts of the system.
Acked-by: Tony Lindgren <tony@atomide.com>
Acked-by: Richard Woodruff <r-woodruff2@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
