linux_dsm_epyc7002/arch/arm64/kernel
Mark Rutland 63a1e1c95e arm64/cpufeature: don't use mutex in bringup path
Currently, cpus_set_cap() calls static_branch_enable_cpuslocked(), which
must take the jump_label mutex.

We call cpus_set_cap() in the secondary bringup path, from the idle
thread where interrupts are disabled. Taking a mutex in this path "is a
NONO" regardless of whether it's contended, and something we must avoid.
We didn't spot this until recently, as ___might_sleep() won't warn for
this case until all CPUs have been brought up.

This patch avoids taking the mutex in the secondary bringup path. The
poking of static keys is deferred until enable_cpu_capabilities(), which
runs in a suitable context on the boot CPU. To account for the static
keys being set later, cpus_have_const_cap() is updated to use another
static key to check whether the const cap keys have been initialised,
falling back to the caps bitmap until this is the case.

This means that users of cpus_have_const_cap() gain should only gain a
single additional NOP in the fast path once the const caps are
initialised, but should always see the current cap value.

The hyp code should never dereference the caps array, since the caps are
initialized before we run the module initcall to initialise hyp. A check
is added to the hyp init code to document this requirement.

This change will sidestep a number of issues when the upcoming hotplug
locking rework is merged.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyniger <marc.zyngier@arm.com>
Reviewed-by: Suzuki Poulose <suzuki.poulose@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Sewior <bigeasy@linutronix.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-05-17 17:00:29 +01:00
..
probes arm64: kprobes: remove kprobe_exceptions_notify 2017-03-10 17:41:19 +00:00
vdso arm64: drop non-existing vdso-offsets.h from .gitignore 2017-03-30 19:29:30 +01:00
.gitignore arm64: Build infrastructure 2012-09-17 13:42:21 +01:00
acpi_numa.c arm64/numa: avoid inconsistent information to be printed 2016-09-09 14:59:08 +01:00
acpi_parking_protocol.c arm64: Use __pa_symbol for kernel symbols 2017-01-12 15:05:39 +00:00
acpi.c efi/bgrt: Enable ACPI BGRT handling on arm64 2017-04-05 12:27:25 +02:00
alternative.c arm64: alternatives: apply boot time fixups via the linear mapping 2017-03-23 13:54:19 +00:00
arm64ksyms.c arm64: switch to RAW_COPY_USER 2017-03-28 18:23:24 -04:00
armv8_deprecated.c arm64: armv8_deprecated: ensure extension of addr 2017-05-09 17:47:05 +01:00
asm-offsets.c arm: kernel: Add SMC structure parameter 2017-02-03 18:46:33 +00:00
cacheinfo.c arm64: cacheinfo: Remove CCSIDR-based cache information probing 2017-03-20 16:16:54 +00:00
cpu_errata.c arm64: cpu_errata: Add capability to advertise Cortex-A73 erratum 858921 2017-04-07 11:22:08 +01:00
cpu_ops.c arm64: apply __ro_after_init to some objects 2016-08-22 12:32:29 +01:00
cpu-reset.h arm64: Use __pa_symbol for kernel symbols 2017-01-12 15:05:39 +00:00
cpu-reset.S arm64: Add back cpu reset routines 2016-06-27 16:31:25 +01:00
cpufeature.c arm64/cpufeature: don't use mutex in bringup path 2017-05-17 17:00:29 +01:00
cpuidle.c arm64: kernel: Update kerneldoc for cpu_suspend() rename 2017-03-10 18:06:24 +00:00
cpuinfo.c arm64: v8.3: Support for weaker release consistency 2017-03-20 16:30:22 +00:00
crash_dump.c arm64: kdump: provide /proc/vmcore file 2017-04-05 18:31:38 +01:00
debug-monitors.c arm64: cpufeature: Make ID reg accessor naming less counterintuitive 2017-04-04 16:55:41 +01:00
efi-entry.S arm64: efi-entry.S: avoid open-coded adr_l 2017-01-17 17:41:14 +00:00
efi-header.S arm64: efi: split Image code and data into separate PE/COFF sections 2017-04-04 17:50:59 +01:00
efi.c arm64: mm: replace 'block_mappings_allowed' with 'page_mappings_only' 2016-11-07 18:15:04 +00:00
entry32.S arm64: entry32: remove pointless register assignment 2015-07-10 16:47:13 +01:00
entry-fpsimd.S arm64: fpsimd: fix a typo in fpsimd_save_partial_state ENDPROC 2014-07-31 11:42:42 +01:00
entry-ftrace.S arm64: include asm/assembler.h in entry-ftrace.S 2017-02-15 11:34:25 +00:00
entry.S arm64: entry: improve data abort handling of tagged pointers 2017-05-09 17:26:59 +01:00
fpsimd.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
ftrace.c ftrace: Add return address pointer to ftrace_ret_stack 2016-08-24 12:15:14 +02:00
head.S Merge branch 'arm64/common-sysreg' of git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux into for-next/core 2017-04-04 18:08:47 +01:00
hibernate-asm.S arm64: Introduce raw_{d,i}cache_line_size 2016-09-09 15:03:29 +01:00
hibernate.c arm64: hibernate: preserve kdump image around hibernation 2017-04-05 18:28:50 +01:00
hw_breakpoint.c arm64: hw_breakpoint: fix watchpoint matching for tagged pointers 2017-05-09 17:26:40 +01:00
hyp-stub.S arm64: hyp-stub: Zero x0 on successful stub handling 2017-04-09 07:49:35 -07:00
image.h arm64 updates for 4.7: 2016-05-16 17:17:24 -07:00
insn.c bpf, arm64: implement jiting of BPF_XADD 2017-05-02 15:04:50 -04:00
io.c arm64: optimize memcpy_{from,to}io() and memset_io() 2014-11-06 17:25:27 +00:00
irq.c arm64: remove irq_count and do_softirq_own_stack() 2015-12-21 17:26:01 +00:00
jump_label.c jump_label: Rename JUMP_LABEL_{EN,DIS}ABLE to JUMP_LABEL_{JMP,NOP} 2015-08-03 11:34:12 +02:00
kaslr.c arm64: kaslr: Fix up the kernel image alignment 2017-03-22 15:43:11 +00:00
kgdb.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
kuser32.S arm64: Add __NR_* definitions for compat syscalls 2014-07-10 11:02:40 +01:00
machine_kexec.c arm64: kdump: add VMCOREINFO's for user-space tools 2017-04-05 18:29:47 +01:00
Makefile arm64: kdump: provide /proc/vmcore file 2017-04-05 18:31:38 +01:00
module-plts.c arm64: module: split core and init PLT sections 2017-04-26 12:31:00 +01:00
module.c arm64: Silence first allocation with CONFIG_ARM64_MODULE_PLTS=y 2017-05-11 14:43:40 +01:00
module.lds arm64: module: split core and init PLT sections 2017-04-26 12:31:00 +01:00
paravirt.c arm64: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops 2015-12-21 14:40:54 +00:00
pci.c PCI/ACPI: Extend pci_mcfg_lookup() to return ECAM config accessors 2016-12-06 13:45:48 -06:00
perf_callchain.c perf core: Add a 'nr' field to perf_event_callchain_context 2016-05-16 23:11:51 -03:00
perf_event.c arm64: perf: Ignore exclude_hv when kernel is running in HYP 2017-05-15 18:30:37 +01:00
perf_regs.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
process.c arm64: drop unnecessary newlines in show_regs() 2017-03-23 14:20:41 +00:00
psci.c arm64: Use __pa_symbol for kernel symbols 2017-01-12 15:05:39 +00:00
ptrace.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
reloc_test_core.c arm64: relocation testing module 2017-04-04 17:03:32 +01:00
reloc_test_syms.S arm64: relocation testing module 2017-04-04 17:03:32 +01:00
relocate_kernel.S arm64: Introduce raw_{d,i}cache_line_size 2016-09-09 15:03:29 +01:00
return_address.c arm64: factor out current_stack_pointer 2016-11-11 18:25:43 +00:00
setup.c arm64: Print DT machine model in setup_machine_fdt() 2017-04-28 17:09:41 +01:00
signal32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
signal.c arm64: Add uprobe support 2016-11-07 18:15:21 +00:00
sleep.S arm64: move sp_el0 and tpidr_el1 into cpu_suspend_ctx 2016-11-11 18:25:44 +00:00
smccc-call.S firmware: qcom: scm: Fix interrupted SCM calls 2017-02-03 18:46:33 +00:00
smp_spin_table.c arm64: Use __pa_symbol for kernel symbols 2017-01-12 15:05:39 +00:00
smp.c arm64 updates for 4.12: 2017-05-05 12:11:37 -07:00
stacktrace.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
suspend.c arm64: move sp_el0 and tpidr_el1 into cpu_suspend_ctx 2016-11-11 18:25:44 +00:00
sys32.c arm64: fix implementation of mmap2 compat syscall 2015-03-19 10:43:51 +00:00
sys_compat.c sched/headers: Prepare for the reduction of <linux/sched.h>'s signal API dependency 2017-03-02 08:42:37 +01:00
sys.c arm64: compat: Check for AArch32 state 2016-04-20 12:22:42 +01:00
time.c arm64: ftrace: fix a stack tracer's output under function graph tracer 2015-12-21 17:26:02 +00:00
topology.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/topology.h> 2017-03-02 08:42:26 +01:00
trace-events-emulation.h arm64: Trace emulation of AArch32 legacy instructions 2014-11-20 16:35:02 +00:00
traps.c arm64: traps: fix userspace cache maintenance emulation on a tagged pointer 2017-05-09 17:26:17 +01:00
vdso.c arm64: Use __pa_symbol for kernel symbols 2017-01-12 15:05:39 +00:00
vmlinux.lds.S arm64: efi: split Image code and data into separate PE/COFF sections 2017-04-04 17:50:59 +01:00