Generic KVM stats are those collected in architecture independent code
or those supported by all architectures; put all generic statistics in
a separate structure. This ensures that they are defined the same way
in the statistics API which is being added, removing duplication among
different architectures in the declaration of the descriptors.
No functional change intended.
Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
Message-Id: <20210618222709.1858088-2-jingzhangos@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The CALL_ON_STACK macro is used to call a C function from inline
assembly, and therefore must consider the C ABI, which says that only
registers 6-13, and 15 are non-volatile (restored by the called
function).
The inline assembly incorrectly marks all registers used to pass
parameters to the called function as read-only input operands, instead
of operands that are read and written to. This might result in
register corruption depending on usage, compiler, and compile options.
Fix this by marking all operands used to pass parameters as read/write
operands. To keep the code simple even register 6, if used, is marked
as read-write operand.
Fixes: ff340d2472 ("s390: add stack switch helper")
Cc: <stable@kernel.org> # 4.20
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Get rid of register asm statement and use a register pair.
This allows the compiler to allocate registers on its own.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Introduce a register pair union, which is supposed to be used for
inline assemblies where instructions require parameters in even/odd
numbered register pairs.
This is more or less the same register pair construct which was
available for 31 bit builds which was removed with commit 5a79859ae0
("s390: remove 31 bit support").
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
All s390 irqflags functions are very small and should be always inlined.
Therefore mark them __always_inline. This also allows to get rid of the
rather odd notrace attribute for these small functions, which was only
added to prevent tracing iff any of these functions would not be inlined.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
s390 is the only architecture which makes use of the __no_kasan_or_inline
attribute for two functions. Given that both stap() and __load_psw_mask()
are very small functions they can and should be always inlined anyway.
Therefore get rid of __no_kasan_or_inline and always inline these
functions.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Currently there are two separate places where kernel memory layout has
to be known and adjusted:
1. early kasan setup.
2. paging setup later.
Those 2 places had to be kept in sync and adjusted to reflect peculiar
technical details of one another. With additional factors which influence
kernel memory layout like ultravisor secure storage limit, complexity
of keeping two things in sync grew up even more.
Besides that if we look forward towards creating identity mapping and
enabling DAT before jumping into uncompressed kernel - that would also
require full knowledge of and control over kernel memory layout.
So, de-duplicate and move kernel memory layout setup logic into
the decompressor.
Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Maintaining a pointer inside the aob's user-definable area is fragile
and unnecessary. At this stage we only need it to overload the buffer's
state field, and to access the buffer's TX queue.
The first part is easily solved by tracking the aob's state within the
aob itself. This also feels much cleaner and self-contained.
For enabling the access to the associated TX queue, we can store the
queue's index in the aob.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To avoid casting ptrace members, add a union containing
both struct tpi_info and explicit int_code/int_parm members.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
For future work we need the struct tpi_info declaration in asm/ptrace.h.
Due to circular dependencies it cannot stay in asm/lowcore.h or asm/cio.h,
which would be the preferred location. Therefore add it in its own header
file.
Also fix a typo in the length of a reserved field that did not have a
functional effect beyond an incorrect field value in the s390_cio_tpi
tracepoint.
Fixes: 2ab59de7c5 ("s390/cio: Consolidate inline assemblies and related data definitions")
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Acked-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
ccwgroup_notifier() currently listens for BUS_NOTIFY_UNBIND_DRIVER
events, and triggers an ungrouping for the affected device.
Looking at __device_release_driver(), we can wait for a little longer
until the driver has been fully unbound and eg. bus->remove() has been
called. So listen for BUS_NOTIFY_UNBOUND_DRIVER instead. Due to locking
the current code should work just fine, but this clarifies our intent.
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Architecture callback switch_mm() is allowed to be called with
enabled interrupts. However, our implementation of switch_mm()
does not expect that. Let's follow other architectures and make
sure switch_mm() is always executed with interrupts disabled,
regardless of what happens with the generic kernel code in the
future.
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Since commit 9a965ea95135 ("s390/kexec_file: Simplify parmarea
access") we have struct parmarea which describes the layout of the
kernel parameter area.
Make the kernel parameter area available as global variable parmarea
of type struct parmarea, which allows to easily access its members.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
gcc-11 warns:
arch/s390/kernel/traps.c: In function __do_pgm_check:
arch/s390/kernel/traps.c:319:17: warning: memcpy reading 256 bytes from a region of size 0 [-Wstringop-overread]
319 | memcpy(¤t->thread.trap_tdb, &S390_lowcore.pgm_tdb, 256);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix this by adding a struct pgm_tdb to struct lowcore and copy that.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
gcc-11 warns:
arch/s390/kernel/irq.c: In function do_ext_irq:
arch/s390/kernel/irq.c:175:9: warning: memcpy reading 4 bytes from a region of size 0 [-Wstringop-overread]
175 | memcpy(®s->int_code, &S390_lowcore.ext_cpu_addr, 4);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix this by adding a struct for int_code to struct lowcore.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
With gcc-11, there are a lot of warnings because the facility functions
are accessing lowcore through a null pointer. Fix this by moving the
facility arrays away from lowcore.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
arch/s390/kernel/syscall.c: In function __do_syscall:
arch/s390/kernel/syscall.c:147:9: warning: memcpy reading 64 bytes from a region of size 0 [-Wstringop-overread]
147 | memcpy(®s->gprs[8], S390_lowcore.save_area_sync, 8 * sizeof(unsigned long));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/s390/kernel/syscall.c:148:9: warning: memcpy reading 4 bytes from a region of size 0 [-Wstringop-overread]
148 | memcpy(®s->int_code, &S390_lowcore.svc_ilc, sizeof(regs->int_code));
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix this by moving the gprs restore from C to assembly, and use a assignment
for int_code instead of memcpy.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In commit b02002cc4c ("s390/pci: Implement ioremap_wc/prot() with
MIO") we implemented both ioremap_wc() and ioremap_prot() however until
now we had not set HAVE_IOREMAP_PROT in Kconfig, do so now.
This also requires implementing pte_pgprot() as this is used in the
generic_access_phys() code enabled by CONFIG_HAVE_IOREMAP_PROT. As with
ioremap_wc() we need to take the MMIO Write Back bit index into account.
Moreover since the pgprot value returned from pte_pgprot() is to be used
for mappings into kernel address space we must make sure that it uses
appropriate kernel page table protection bits. In particular a pgprot
value originally coming from userspace could have the _PAGE_PROTECT
bit set to enable fault based dirty bit accounting which would then make
the mapping inaccessible when used in kernel address space.
Fixes: b02002cc4c ("s390/pci: Implement ioremap_wc/prot() with MIO")
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
The command 'perf stat -e cycles ...' triggers the following function
sequence in the CPU Measurement Facility counter device driver:
perf_pmu_event_init()
__hw_perf_event_init()
validate_ctr_auth()
validate_ctr_version()
During event creation, the counter number is checked in functions
validate_ctr_auth() and validate_ctr_version() to verify it is a valid
counter and supported by the hardware. If this is not the case, both
functions return an error and the event is not created. System call
perf_event_open() returns an error in this case.
Later on the event is installed in the kernel event subsystem and the
driver functions cpumf_pmu_add() and cpumf_pmu_commit_txn() are called
to install the counter event by the hardware.
Since both events have been verified at event creation, there is no need
to re-evaluate the authorization state. This can not change since on
* LPARs the authorization change requires a restart of the LPAR (and
thus a reboot of the kernel)
* DPMs can not take resources away, just add them.
Also the sequence of CPU Measurement facility counter device driver
calls is
cpumf_pmu_start_txn
cpumf_pmu_add
cpumf_pmu_start
cpumf_pmu_commit_txn
for every single event. Which means the condition in cpumf_pmu_add()
is never met and validate_ctr_auth() is never called.
This leaves the counter device driver transaction functions with
just one task:
start_txn: Verify a transaction is not in flight and call
perf_pmu_disable()
cancel_txn, commit_txn: Verify a transaction is in flight and call
perf_pmu_enable()
The same functionality is provided by the default transaction handling
functions in kernel/events/core.c. Use those by removing the
counter device driver private call back functions.
Suggested-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
In an upcoming change we would like to add a flag to
GFP_HIGHUSER_MOVABLE so that it would no longer be an OR
of GFP_HIGHUSER and __GFP_MOVABLE. This poses a problem for
alloc_zeroed_user_highpage_movable() which passes __GFP_MOVABLE
into an arch-specific __alloc_zeroed_user_highpage() hook which ORs
in GFP_HIGHUSER.
Since __alloc_zeroed_user_highpage() is only ever called from
alloc_zeroed_user_highpage_movable(), we can remove one level
of indirection here. Remove __alloc_zeroed_user_highpage(),
make alloc_zeroed_user_highpage_movable() the hook, and use
GFP_HIGHUSER_MOVABLE in the hook implementations so that they will
pick up the new flag that we are going to add.
Signed-off-by: Peter Collingbourne <pcc@google.com>
Link: https://linux-review.googlesource.com/id/Ic6361c657b2cdcd896adbe0cf7cb5a7fbb1ed7bf
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210602235230.3928842-2-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>
Subsequent patches will move architectures over to the ARCH_ATOMIC API,
after preparing the asm-generic atomic implementations to function with
or without ARCH_ATOMIC.
As some architectures use the asm-generic implementations exclusively
(and don't have a local atomic.h), and to avoid the risk that
ARCH_ATOMIC isn't defined in some cases we expect, let's make the
ARCH_ATOMIC macro a Kconfig symbol instead, so that we can guarantee it
is consistently available where needed.
There should be no functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-2-mark.rutland@arm.com
As pointed out by commit
de9b8f5dcb ("sched: Fix crash trying to dequeue/enqueue the idle thread")
init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.
As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().
Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().
Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().
Secondary startups were patched via coccinelle:
@begone@
@@
-preempt_disable();
...
cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
Pull more s390 updates from Heiko Carstens:
- add support for system call stack randomization
- handle stale PCI deconfiguration events
- couple of defconfig updates
- some fixes and cleanups
* tag 's390-5.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390: fix detection of vector enhancements facility 1 vs. vector packed decimal facility
s390/entry: add support for syscall stack randomization
s390/configs: change CONFIG_VIRTIO_CONSOLE to "m"
s390/cio: remove invalid condition on IO_SCH_UNREG
s390/cpumf: remove call to perf_event_update_userpage
s390/cpumf: move counter set size calculation to common place
s390/cpumf: beautify if-then-else indentation
s390/configs: enable CONFIG_PCI_IOV
s390/pci: handle stale deconfiguration events
s390/pci: rename zpci_configure_device()
Pull kvm updates from Paolo Bonzini:
"This is a large update by KVM standards, including AMD PSP (Platform
Security Processor, aka "AMD Secure Technology") and ARM CoreSight
(debug and trace) changes.
ARM:
- CoreSight: Add support for ETE and TRBE
- Stage-2 isolation for the host kernel when running in protected
mode
- Guest SVE support when running in nVHE mode
- Force W^X hypervisor mappings in nVHE mode
- ITS save/restore for guests using direct injection with GICv4.1
- nVHE panics now produce readable backtraces
- Guest support for PTP using the ptp_kvm driver
- Performance improvements in the S2 fault handler
x86:
- AMD PSP driver changes
- Optimizations and cleanup of nested SVM code
- AMD: Support for virtual SPEC_CTRL
- Optimizations of the new MMU code: fast invalidation, zap under
read lock, enable/disably dirty page logging under read lock
- /dev/kvm API for AMD SEV live migration (guest API coming soon)
- support SEV virtual machines sharing the same encryption context
- support SGX in virtual machines
- add a few more statistics
- improved directed yield heuristics
- Lots and lots of cleanups
Generic:
- Rework of MMU notifier interface, simplifying and optimizing the
architecture-specific code
- a handful of "Get rid of oprofile leftovers" patches
- Some selftests improvements"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (379 commits)
KVM: selftests: Speed up set_memory_region_test
selftests: kvm: Fix the check of return value
KVM: x86: Take advantage of kvm_arch_dy_has_pending_interrupt()
KVM: SVM: Skip SEV cache flush if no ASIDs have been used
KVM: SVM: Remove an unnecessary prototype declaration of sev_flush_asids()
KVM: SVM: Drop redundant svm_sev_enabled() helper
KVM: SVM: Move SEV VMCB tracking allocation to sev.c
KVM: SVM: Explicitly check max SEV ASID during sev_hardware_setup()
KVM: SVM: Unconditionally invoke sev_hardware_teardown()
KVM: SVM: Enable SEV/SEV-ES functionality by default (when supported)
KVM: SVM: Condition sev_enabled and sev_es_enabled on CONFIG_KVM_AMD_SEV=y
KVM: SVM: Append "_enabled" to module-scoped SEV/SEV-ES control variables
KVM: SEV: Mask CPUID[0x8000001F].eax according to supported features
KVM: SVM: Move SEV module params/variables to sev.c
KVM: SVM: Disable SEV/SEV-ES if NPT is disabled
KVM: SVM: Free sev_asid_bitmap during init if SEV setup fails
KVM: SVM: Zero out the VMCB array used to track SEV ASID association
x86/sev: Drop redundant and potentially misleading 'sev_enabled'
KVM: x86: Move reverse CPUID helpers to separate header file
KVM: x86: Rename GPR accessors to make mode-aware variants the defaults
...
Pull powerpc updates from Michael Ellerman:
- Enable KFENCE for 32-bit.
- Implement EBPF for 32-bit.
- Convert 32-bit to do interrupt entry/exit in C.
- Convert 64-bit BookE to do interrupt entry/exit in C.
- Changes to our signal handling code to use user_access_begin/end()
more extensively.
- Add support for time namespaces (CONFIG_TIME_NS)
- A series of fixes that allow us to reenable STRICT_KERNEL_RWX.
- Other smaller features, fixes & cleanups.
Thanks to Alexey Kardashevskiy, Andreas Schwab, Andrew Donnellan, Aneesh
Kumar K.V, Athira Rajeev, Bhaskar Chowdhury, Bixuan Cui, Cédric Le
Goater, Chen Huang, Chris Packham, Christophe Leroy, Christopher M.
Riedl, Colin Ian King, Dan Carpenter, Daniel Axtens, Daniel Henrique
Barboza, David Gibson, Davidlohr Bueso, Denis Efremov, dingsenjie,
Dmitry Safonov, Dominic DeMarco, Fabiano Rosas, Ganesh Goudar, Geert
Uytterhoeven, Geetika Moolchandani, Greg Kurz, Guenter Roeck, Haren
Myneni, He Ying, Jiapeng Chong, Jordan Niethe, Laurent Dufour, Lee
Jones, Leonardo Bras, Li Huafei, Madhavan Srinivasan, Mahesh Salgaonkar,
Masahiro Yamada, Nathan Chancellor, Nathan Lynch, Nicholas Piggin,
Oliver O'Halloran, Paul Menzel, Pu Lehui, Randy Dunlap, Ravi Bangoria,
Rosen Penev, Russell Currey, Santosh Sivaraj, Sebastian Andrzej Siewior,
Segher Boessenkool, Shivaprasad G Bhat, Srikar Dronamraju, Stephen
Rothwell, Thadeu Lima de Souza Cascardo, Thomas Gleixner, Tony Ambardar,
Tyrel Datwyler, Vaibhav Jain, Vincenzo Frascino, Xiongwei Song, Yang Li,
Yu Kuai, and Zhang Yunkai.
* tag 'powerpc-5.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (302 commits)
powerpc/signal32: Fix erroneous SIGSEGV on RT signal return
powerpc: Avoid clang uninitialized warning in __get_user_size_allowed
powerpc/papr_scm: Mark nvdimm as unarmed if needed during probe
powerpc/kvm: Fix build error when PPC_MEM_KEYS/PPC_PSERIES=n
powerpc/kasan: Fix shadow start address with modules
powerpc/kernel/iommu: Use largepool as a last resort when !largealloc
powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs
powerpc/44x: fix spelling mistake in Kconfig "varients" -> "variants"
powerpc/iommu: Annotate nested lock for lockdep
powerpc/iommu: Do not immediately panic when failed IOMMU table allocation
powerpc/iommu: Allocate it_map by vmalloc
selftests/powerpc: remove unneeded semicolon
powerpc/64s: remove unneeded semicolon
powerpc/eeh: remove unneeded semicolon
powerpc/selftests: Add selftest to test concurrent perf/ptrace events
powerpc/selftests/perf-hwbreak: Add testcases for 2nd DAWR
powerpc/selftests/perf-hwbreak: Coalesce event creation code
powerpc/selftests/ptrace-hwbreak: Add testcases for 2nd DAWR
powerpc/configs: Add IBMVNIC to some 64-bit configs
selftests/powerpc: Add uaccess flush test
...
This adds support for adding a random offset to the stack while handling
syscalls. The patch uses get_tod_clock_fast() as this is considered good
enough and has much less performance penalty compared to using
get_random_int(). The patch also adds randomization in pgm_check_handler()
as the sigreturn/rt_sigreturn system calls might be called from there.
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Link: https://lore.kernel.org/r/20210429091451.1062594-1-svens@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
The function to calculate the size of counter sets is renamed from
cf_diag_ctrset_size() to cpum_cf_ctrset_size() and moved to the file
containing common functions for the CPU Measurement Counter Facility.
No functional change.
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Acked-by : Sumanth Korikkar <sumanthk@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
With zpci_configure_device() now always called on a device that has
already been configured on the platform level its name has become
misleading. Rename it to zpci_scan_configured_device() to signify that
the function now only handles the correct scanning of a newly configured
PCI function taking care of the special handling necessary for function
0 and functions parked waiting for a PCI bus that can't be created
without first seeing function 0.
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Make sure to always inline __xchg() and __cmpxchg() otherwise the
compiler might decide to generate out-of-line versions which will
fail at link time:
s390-linux-ld: lib/atomic64_test.o: in function `__xchg':
>> atomic64_test.c:(.text.unlikely+0xa4): undefined reference to `__xchg_called_with_bad_pointer'
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/linux-mm/202104170449.SIIFKVjT-lkp@intel.com/
Fixes: d2b1f6d2d3 ("s390/cmpxchg: get rid of gcc atomic builtins")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Old gcc versions may fail with an internal compiler error if only the
T or S constraint is specified for an operand, and no displacement is
needed at all.
To fix this use RT and QS as constraints, which reflects the union of
both. Later gcc versions do the right thing and always accept single T
and S constraints.
See gcc commit 3e4be43f69da ("S/390: Memory constraint cleanup").
Fixes: ca897bb181 ("s390/atomic: use proper constraints")
Fixes: b23eb636d7 ("s390/atomic: get rid of gcc atomic builtins")
Fixes: d2b1f6d2d3 ("s390/cmpxchg: get rid of gcc atomic builtins")
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
gcc and clang warn about incompatible pointer types due to the recent
cmpxchg changes:
drivers/gpu/drm/drm_lock.c:75:10: error: passing 'typeof (lock)' (aka 'volatile unsigned int *') to parameter of type 'void *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
prev = cmpxchg(lock, old, new);
^~~~~~~~~~~~~~~~~~~~~~~
include/asm-generic/atomic-instrumented.h:1685:2: note: expanded from macro 'cmpxchg'
arch_cmpxchg(__ai_ptr, __VA_ARGS__); \
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To avoid this simply cast pointers to unsigned long and use them
instead of void pointers. This allows to stay with functions, instead
of using complex defines and having to deal with all their potential
side effects.
Reported-by: kernel test robot <lkp@intel.com>
Fixes: d2b1f6d2d3 ("s390/cmpxchg: get rid of gcc atomic builtins")
Link: https://lore.kernel.org/linux-s390/202104130131.sMmSqpb5-lkp@intel.com/
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Add arch_ prefix to all atomic operations, and define ARCH_ATOMIC.
This enables KASAN instrumentation for all atomic operations on s390.
This is the s390 variant of commit 8bf705d130 ("locking/atomic/x86:
Switch atomic.h to use atomic-instrumented.h").
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
s390 is the only architecture in the kernel which makes use of gcc's
atomic builtin functions. Even though I don't see any technical
problem with that right now, remove this code and open-code
compare-and-swap loops again, like every other architecture is doing
it also.
We can switch to a generic implementation when other architectures are
doing that also.
See also https://lwn.net/Articles/586838/ for forther details.
This basically reverts commit f318a1229b ("s390/cmpxchg: use
compiler builtins").
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
s390 is the only architecture in the kernel which makes use of gcc's
atomic builtin functions. Even though I don't see any technical
problem with that right now, remove this code and open-code
compare-and-swap loops again, like every other architecture is doing
it also.
We can switch to a generic implementation when other architectures are
doing that also.
See also https://lwn.net/Articles/586838/ for forther details.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Use the R,T, and S constraints instead of the Q constraint in atomic
inline assemblies wherever possible. This allows the compiler to
generate better code. (~ -2kb code size).
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
