| Commit message (Collapse) | Author | Age |
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Perf has three ways to name a PMU: either by passing an explicit char *,
reading arm_pmu->name or accessing arm_pmu->pmu.name.
Just use arm_pmu->name consistently in the ARM backend.
Signed-off-by: Will Deacon <will.deacon@arm.com>
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When attempting to reset the PMU state for either a NULL PMU or a PMU
implementation without a reset function, return NOTIFY_DONE from the CPU
notifier as we don't care about the hotplug event.
Signed-off-by: Will Deacon <will.deacon@arm.com>
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The current practice of registering the cpu hotplug notifier at PMU
registration time won't be safe with multiple PMUs, as we'll repeatedly
attempt to register the notifier. This has the unfortunate effect of
silently corrupting the notifier list, leading to boot stalling.
Instead, register the notifier at init time. Its sanity checks will
prevent anything bad from happening if the notifier is called before we
have any PMUs registered.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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Multi-cluster ARMv7 systems may have CPU PMUs with different number of
counters.
This patch updates armv7_pmnc_counter_valid so that it takes a pmu
argument and checks the counter validity against that. We also remove a
number of redundant counter checks whether the current PMU is not easily
retrievable.
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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The arm_pmu functions have wildly varied parameters which can often be
derived from struct perf_event.
This patch changes the arm_pmu function prototypes so that struct
perf_event pointers are passed in preference to fields that can be
derived from the event.
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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Supporting multiple, heterogeneous CPU PMUs requires us to allocate the
arm_pmu structures dynamically as the devices are probed.
This patch removes the static structure definitions for each CPU PMU
type and instead passes pointers to the PMU-specific init functions.
Signed-off-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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Add minimal guest support to perf, so it can distinguish whether
the PMU interrupt was in the host or the guest, as well as collecting
some very basic information (guest PC, user vs kernel mode).
This is not feature complete though, as it doesn't support backtracing
in the guest.
Based on the x86 implementation, tested with KVM/ARM.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
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'warnings' into for-next
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syscall_trace_exit is currently doing things back-to-front; invoking
the audit hook *after* signalling the debugger, which presents an
opportunity for the registers to be re-written by userspace in order to
bypass auditing constaints.
This patch fixes the ordering by moving the audit code first and the
tracehook code last. On the face of it, it looks like
current_thread_info()->syscall may be incorrect for the sys_exit
tracepoint, but that's actually not an issue because it will have been
set during syscall entry and cannot have changed since then.
Reported-by: Andrew Gabbasov <Andrew_Gabbasov@mentor.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This patch keeps disabled the strict alignment CP15 bit for
all armv6 and armv7 processor without the mmu. This behaviour
is now same as in the mmu case.
Signed-off-by: Armando Visconti <armando.visconti@st.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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On tracehook-friendly platforms, a system call number of -1 falls
through without running much code or taking much action.
ARM is different. This adds a short-circuit check in the trace path to
avoid any additional work, as suggested by Russell King, to make sure
that ARM behaves the same way as other platforms.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Drewry <wad@chromium.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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There is very little difference in the TIF_SECCOMP and TIF_SYSCALL_WORK
path in entry-common.S, so merge TIF_SECCOMP into TIF_SYSCALL_WORK and
move seccomp into the syscall_trace_enter() handler.
Expanded some of the tracehook logic into the callers to make this code
more readable. Since tracehook needs to do register changing, this portion
is best left in its own function instead of copy/pasting into the callers.
Additionally, the return value for secure_computing() is now checked
and a -1 value will result in the system call being skipped.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Drewry <wad@chromium.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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setup_mm_for_reboot()
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Add function arch_send_wakeup_ipi_mask(), so that platform code can
use it as an easy way to wake up cores that are in WFI.
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Add the ARM machine identifier to sortextable and select the
config option so that we can sort the exception table at compile
time. sortextable relies on a section named __ex_table existing
in the vmlinux, but ARM's linker script places the exception
table in the data section. Give the exception table its own
section so that sortextable can find it.
This allows us to skip the sorting step during boot.
Cc: David Daney <david.daney@cavium.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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It has been brought to my knowledge that the .setup()/.stop()
function pair in the SMP TWD is going to be called from atomic
contexts for CPUs coming and going, and then the
clk_prepare()/clk_unprepare() calls cannot be called
on subsequent .setup()/.stop() iterations. This is however
just the tip of an iceberg as the function pair is not
designed to be reentrant at all.
This change makes the SMP_TWD clock .setup()/.stop() pair reentrant
by splitting the .setup() function in three parts:
- One COMMON part that is executed the first time the first CPU
in the TWD cluster is initialized. This will fetch the TWD
clk for the cluster and prepare+enable it. If no clk is
available it will calibrate the rate instead.
- One part that is executed the FIRST TIME a certain CPU is
brought on-line. This initializes and sets up the clock event
for a certain CPU.
- One part that is executed on every subsequent .setup() call.
This will re-initialize the clock event. This is augmented
to call the clk_enable()/clk_disable() pair properly.
Cc: Shawn Guo <shawn.guo@linaro.org>
Reported-by: Peter Chen <peter.chen@freescale.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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A minor code refactoring saving a few lines by merging prepare()
and enable() calls.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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1. On ARM platform, "nohlt" can be used to prevent core from idle
process, returning immediately.
2. There are two interfaces, exported for other modules, named
"disable_hlt" and "enable_hlt" are used to enable/disable the
cpuidle mechanism by increasing/decreasing "hlt_counter".
Disable_hlt and enable_hlt are paired operation,
when you first call disable_hlt and then enable_hlt, the
semantics are right.
3. There is no obvious constraint to prevent user(driver/module)
code to prevent the case that enable_hlt is ahead of disable_hlt,
which is a fatal operation on kernel state change from user,
and there is no any WARNING or notification if the case happens
in current kernel code.
This patch aims to report BUG when the case happens, just like
what the kernel do when enable_irq is ahead of disable_irq.
Link: https://patchwork.kernel.org/patch/1527881/
Signed-off-by: fwu <fwu@marvell.com>
Signed-off-by: YiLu Mao <ylmao@marvell.com>
Signed-off-by: Ning Jiang <ning.jiang@marvell.com>
Acked-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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This is what is done for the regular interrupts in kernel/irqs/proc.c
already, before calling arch_show_interrupts(). Not doing so for the
IPIs causes the column headers not to match with the content whenever
some CPUs are offline.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Pull arm fixes from Russell King:
"Not much here again.
The two most notable things here are the sched_clock() fix, which was
causing problems with the scheduling of threaded IRQs after a suspend
event, and the vfp fix, which afaik has only been seen on some older
OMAP boards. Nevertheless, both are fairly important fixes."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: 7569/1: mm: uninitialized warning corrections
ARM: 7567/1: io: avoid GCC's offsettable addressing modes for halfword accesses
ARM: 7566/1: vfp: fix save and restore when running on pre-VFPv3 and CONFIG_VFPv3 set
ARM: 7565/1: sched: stop sched_clock() during suspend
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The scheduler imposes a requirement to sched_clock()
which is to stop the clock during suspend, if we don't
do that any RT thread will be rescheduled in the future
which might cause any sort of problems.
This became an issue on OMAP when we converted omap-i2c.c
to use threaded IRQs, it turned out that depending on how
much time we spent on suspend, the I2C IRQ thread would
end up being rescheduled so far in the future that I2C
transfers would timeout and, because omap_hsmmc depends
on an I2C-connected device to detect if an MMC card is
inserted in the slot, our rootfs would just vanish.
arch/arm/kernel/sched_clock.c already had an optional
implementation (sched_clock_needs_suspend()) which would
handle scheduler's requirement properly, what this patch
does is simply to make that implementation non-optional.
Note that this has the side-effect that printk timings
won't reflect the actual time spent on suspend so other
methods to measure that will have to be used.
This has been tested with beagleboard XM (OMAP3630) and
pandaboard rev A3 (OMAP4430). Suspend to RAM is now working
after this patch.
Thanks to Kevin Hilman for helping out with debugging.
Acked-by: Kevin Hilman <khilman@ti.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Pull ARM fixes from Russell King:
"A random collection of various fixes, mainly from Arnd and a few other
people. Not thing really stands out here."
* 'fixes' of git://git.linaro.org/people/rmk/linux-arm:
ARM: drop experimental status for hotplug and Thumb2
ARM: 7560/1: SMP_TWD: use DIV_ROUND_CLOSEST() for periodic mode
ARM: 7559/1: smp: switch away from the idmap before updating init_mm.mm_count
ARM: 7556/1: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD
ARM: 7555/1: kexec: fix segment memory addresses check
ARM: warnings in arch/arm/include/asm/uaccess.h
ARM: binfmt_flat: unused variable 'persistent'
ARM: be really quiet when building with 'make -s'
ARM: pass -marm to gcc by default for both C and assembler
ARM: Xen: fix initial build problems
ARM: export default read_current_timer
ARM: Fix another build warning in arch/arm/mm/alignment.c
ARM: export set_irq_flags
ARM: kprobes: make more tests conditional
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc into fixes
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The recently added Emma Mobile GPIO driver calls set_irq_flags
and irq_set_chip_and_handler for the interrupts it exports and
it can be built as a module, which currently fails with
ERROR: "set_irq_flags" [drivers/gpio/gpio-em.ko] undefined!
We either need to replace the call to set_irq_flags with something
else or export that function. This patch does the latter.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Magnus Damm <damm@opensource.se>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
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The mls instruction is not available in ARMv6K or below, so we
should make the test conditional on at least ARMv7. ldrexd/strexd
are available in ARMv6K or ARMv7, which we can test by checking
the CONFIG_CPU_32v6K symbol.
/tmp/ccuMTZ8D.s: Assembler messages:
/tmp/ccuMTZ8D.s:22188: Error: selected processor does not support ARM mode `mls r0,r1,r2,r3'
/tmp/ccuMTZ8D.s:22222: Error: selected processor does not support ARM mode `mlshi r7,r8,r9,r10'
/tmp/ccuMTZ8D.s:22252: Error: selected processor does not support ARM mode `mls lr,r1,r2,r13'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Jon Medhurst <tixy@yxit.co.uk>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Leif Lindholm <leif.lindholm@arm.com>
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The periodic mode is currently calculated by a simple division
but we should pay more attention to our integer arithmetics.
Also delete a comment that does not make any sense.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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When booting a secondary CPU, the primary CPU hands two sets of page
tables via the secondary_data struct:
(1) swapper_pg_dir: a normal, cacheable, shared (if SMP) mapping
of the kernel image (i.e. the tables used by init_mm).
(2) idmap_pgd: an uncached mapping of the .idmap.text ELF
section.
The idmap is generally used when enabling and disabling the MMU, which
includes early CPU boot. In this case, the secondary CPU switches to
swapper as soon as it enters C code:
struct mm_struct *mm = &init_mm;
unsigned int cpu = smp_processor_id();
/*
* All kernel threads share the same mm context; grab a
* reference and switch to it.
*/
atomic_inc(&mm->mm_count);
current->active_mm = mm;
cpumask_set_cpu(cpu, mm_cpumask(mm));
cpu_switch_mm(mm->pgd, mm);
This causes a problem on ARMv7, where the identity mapping is treated as
strongly-ordered leading to architecturally UNPREDICTABLE behaviour of
exclusive accesses, such as those used by atomic_inc.
This patch re-orders the secondary_start_kernel function so that we
switch to swapper before performing any exclusive accesses.
Cc: <stable@vger.kernel.org>
Cc: David McKay <david.mckay@st.com>
Reported-by: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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The PERF_EVENT_IOC_PERIOD ioctl command can be used to change the
sample period of a running perf_event. Consequently, when calculating
the next event period, the new period will only be considered after the
previous one has overflowed.
This patch changes the calculation of the remaining event ticks so that
they are offset if the period has changed.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Andreas Sandberg <andreas.sandberg@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Commit c564df4db85aac8d1d65a56176a0a25f46138064 (ARM: 7540/1: kexec:
Check segment memory addresses) added a safety check with accidentally
reversed condition, and broke kexec functionality on ARM. Fix this.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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Daniel Mack reports an oops at boot with the latest kernels:
Internal error: Oops - undefined instruction: 0 [#1] SMP THUMB2
Modules linked in:
CPU: 0 Not tainted (3.6.0-11057-g584df1d #145)
PC is at cpsw_probe+0x45a/0x9ac
LR is at trace_hardirqs_on_caller+0x8f/0xfc
pc : [<c03493de>] lr : [<c005e81f>] psr: 60000113
sp : cf055fb0 ip : 00000000 fp : 00000000
r10: 00000000 r9 : 00000000 r8 : 00000000
r7 : 00000000 r6 : 00000000 r5 : c0344555 r4 : 00000000
r3 : cf057a40 r2 : 00000000 r1 : 00000001 r0 : 00000000
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user
Control: 50c5387d Table: 8f3f4019 DAC: 00000015
Process init (pid: 1, stack limit = 0xcf054240)
Stack: (0xcf055fb0 to 0xcf056000)
5fa0: 00000001 00000000 00000000 00000000
5fc0: cf055fb0 c000d1a8 00000000 00000000 00000000 00000000 00000000 00000000
5fe0: 00000000 be9b3f10 00000000 b6f6add0 00000010 00000000 aaaabfaf a8babbaa
The analysis of this is as follows. In init/main.c, we issue:
kernel_thread(kernel_init, NULL, CLONE_FS | CLONE_SIGHAND);
This creates a new thread, which falls through to the ret_from_fork
assembly, with r4 set NULL and r5 set to kernel_init. You can see
this in your oops dump register set - r5 is 0xc0344555, which is the
address of kernel_init plus 1 which marks the function as Thumb code.
Now, let's look at this code a little closer - this is what the
disassembly looks like:
c000d180 <ret_from_fork>:
c000d180: f03a fe08 bl c0047d94 <schedule_tail>
c000d184: 2d00 cmp r5, #0
c000d186: bf1e ittt ne
c000d188: 4620 movne r0, r4
c000d18a: 46fe movne lr, pc <-- XXXXXXX
c000d18c: 46af movne pc, r5
c000d18e: 46e9 mov r9, sp
c000d190: ea4f 3959 mov.w r9, r9, lsr #13
c000d194: ea4f 3949 mov.w r9, r9, lsl #13
c000d198: e7c8 b.n c000d12c <ret_to_user>
c000d19a: bf00 nop
c000d19c: f3af 8000 nop.w
This code was introduced in 9fff2fa0db911 (arm: switch to saner
kernel_execve() semantics). I have marked one instruction, and it's
the significant one - I'll come back to that later.
Eventually, having had a successful call to kernel_execve(), kernel_init()
returns zero.
In returning, it uses the value in 'lr' which was set by the instruction
I marked above. Unfortunately, this causes lr to contain 0xc000d18e -
an even address. This switches the ISA to ARM on return but with a non
word aligned PC value.
So, what do we end up executing? Well, not the instructions above - yes
the opcodes, but they don't mean the same thing in ARM mode. In ARM mode,
it looks like this instead:
c000d18c: 46e946af strbtmi r4, [r9], pc, lsr #13
c000d190: 3959ea4f ldmdbcc r9, {r0, r1, r2, r3, r6, r9, fp, sp, lr, pc}^
c000d194: 3949ea4f stmdbcc r9, {r0, r1, r2, r3, r6, r9, fp, sp, lr, pc}^
c000d198: bf00e7c8 svclt 0x0000e7c8
c000d19c: 8000f3af andhi pc, r0, pc, lsr #7
c000d1a0: e88db092 stm sp, {r1, r4, r7, ip, sp, pc}
c000d1a4: 46e81fff ; <UNDEFINED> instruction: 0x46e81fff
c000d1a8: 8a00f3ef bhi 0xc004a16c
c000d1ac: 0a0cf08a beq 0xc03493dc
I have included more above, because it's relevant. The PSR flags which
we can see in the oops dump are nZCv, so Z and C are set.
All the above ARM instructions are not executed, except for two.
c000d1a0, which has no writeback, and writes below the current stack
pointer (and that data is lost when we take the next exception.) The
other instruction which is executed is c000d1ac, which takes us to...
0xc03493dc. However, remember that bit 1 of the PC got set. So that
makes the PC value 0xc03493de.
And that value is the value we find in the oops dump for PC. What is
the instruction here when interpreted in ARM mode?
0: f71e150c ; <UNDEFINED> instruction: 0xf71e150c
and there we have our undefined instruction (remember that the 'never'
condition code, 0xf, has been deprecated and is now always executed as
it is now being used for additional instructions.)
This path also nicely explains the state of the stack we see in the oops
dump too.
The above is a consistent and sane story for how we got to the oops
dump, which all stems from the instruction at 0xc000d18a being wrong.
Reported-by: Daniel Mack <zonque@gmail.com>
Tested-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull third pile of kernel_execve() patches from Al Viro:
"The last bits of infrastructure for kernel_thread() et.al., with
alpha/arm/x86 use of those. Plus sanitizing the asm glue and
do_notify_resume() on alpha, fixing the "disabled irq while running
task_work stuff" breakage there.
At that point the rest of kernel_thread/kernel_execve/sys_execve work
can be done independently for different architectures. The only
pending bits that do depend on having all architectures converted are
restrictred to fs/* and kernel/* - that'll obviously have to wait for
the next cycle.
I thought we'd have to wait for all of them done before we start
eliminating the longjump-style insanity in kernel_execve(), but it
turned out there's a very simple way to do that without flagday-style
changes."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal:
alpha: switch to saner kernel_execve() semantics
arm: switch to saner kernel_execve() semantics
x86, um: convert to saner kernel_execve() semantics
infrastructure for saner ret_from_kernel_thread semantics
make sure that kernel_thread() callbacks call do_exit() themselves
make sure that we always have a return path from kernel_execve()
ppc: eeh_event should just use kthread_run()
don't bother with kernel_thread/kernel_execve for launching linuxrc
alpha: get rid of switch_stack argument of do_work_pending()
alpha: don't bother passing switch_stack separately from regs
alpha: take SIGPENDING/NOTIFY_RESUME loop into signal.c
alpha: simplify TIF_NEED_RESCHED handling
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Pull second set of ARM updates from Russell King:
"This is the second set of ARM updates for this merge window.
Contained within are changes to allow the kernel to boot in hypervisor
mode on CPUs supporting virtualization, and cache flushing support to
the point of inner sharable unification, which are used by the
suspend/resume code to avoid having to do a full cache flush.
Also included is one fix for VFP code identified by Michael Olbrich."
* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm:
ARM: vfp: fix saving d16-d31 vfp registers on v6+ kernels
ARM: 7549/1: HYP: fix boot on some ARM1136 cores
ARM: 7542/1: mm: fix cache LoUIS API for xscale and feroceon
ARM: mm: update __v7_setup() to the new LoUIS cache maintenance API
ARM: kernel: update __cpu_disable to use cache LoUIS maintenance API
ARM: kernel: update cpu_suspend code to use cache LoUIS operations
ARM: mm: rename jump labels in v7_flush_dcache_all function
ARM: mm: implement LoUIS API for cache maintenance ops
ARM: virt: arch_timers: enable access to physical timers
ARM: virt: Add CONFIG_ARM_VIRT_EXT option
ARM: virt: Add boot-time diagnostics
ARM: virt: Update documentation for hyp mode entry support
ARM: zImage/virt: hyp mode entry support for the zImage loader
ARM: virt: allow the kernel to be entered in HYP mode
ARM: opcodes: add __ERET/__MSR_ELR_HYP instruction encoding
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Conflicts:
arch/arm/kernel/smp.c
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git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into devel-stable
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If booting in HYP mode, it makes sense to enable the use of the
physical timers, so the kernel can use them directly.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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In order to easily detect pathological cases, print some diagnostics
when the kernel boots.
This also provides helpers to detect that HYP mode is actually available,
which can be used by other subsystems to enable HYP specific features.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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The zImage loader needs to turn on the MMU in order to take
advantage of caching while decompressing the zImage. Running this
in hyp mode would require the LPAE pagetable format to be
supported; to avoid this complexity, this patch switches out of hyp
mode, and returns back to hyp mode just before booting the kernel.
This implementation assumes that the Hyp mode view of memory and the
PL1 view of memory are coherent, providing that the MMU and caches
are off in both, as required by the boot protocol. The zImage
decompression code must drain the write buffer on completion anyway, and
entry into Hyp mode should flush any prefetch buffer, avoiding hazards
associated with local write buffers and the pipeline.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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This patch does two things:
* Ensure that asynchronous aborts are masked at kernel entry.
The bootloader should be masking these anyway, but this reduces
the damage window just in case it doesn't.
* Enter svc mode via exception return to ensure that CPU state is
properly serialised. This does not matter when switching from
an ordinary privileged mode ("PL1" modes in ARMv7-AR rev C
parlance), but it potentially does matter when switching from a
another privileged mode such as hyp mode.
This should allow the kernel to boot safely either from svc mode or
hyp mode, even if no support for use of the ARM Virtualization
Extensions is built into the kernel.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
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When a CPU is hotplugged out caches that reside in its power domain
lose their contents and so must be cleaned to the next memory level.
Currently, __cpu_disable calls flush_cache_all() that for new generation
processor like A15/A7 ends up cleaning and invalidating all cache levels
up to Level of Coherency, which includes the unified L2.
This ends up being a waste of cycles since the L2 cache contents are not
lost on power down.
This patch updates __cpu_disable to use the new LoUIS API cache operations.
Acked-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
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In processors like A15/A7 L2 cache is unified and integrated within the
processor cache hierarchy, so that it is not considered an outer cache
anymore. For processors like A15/A7 flush_cache_all() ends up cleaning
all cache levels up to Level of Coherency (LoC) that includes
the L2 unified cache.
When a single CPU is suspended (CPU idle) a complete L2 clean is not
required, so generic cpu_suspend code must clean the data cache using the
newly introduced cache LoUIS function.
The context and stack pointer (context pointer) are cleaned to main memory
using cache area functions that operate on MVA and guarantee that the data
is written back to main memory (perform cache cleaning up to the Point of
Coherency - PoC) so that the processor can fetch the context when the MMU
is off in the cpu_resume code path.
outer_cache management remains unchanged.
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull pile 2 of execve and kernel_thread unification work from Al Viro:
"Stuff in there: kernel_thread/kernel_execve/sys_execve conversions for
several more architectures plus assorted signal fixes and cleanups.
There'll be more (in particular, real fixes for the alpha
do_notify_resume() irq mess)..."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (43 commits)
alpha: don't open-code trace_report_syscall_{enter,exit}
Uninclude linux/freezer.h
m32r: trim masks
avr32: trim masks
tile: don't bother with SIGTRAP in setup_frame
microblaze: don't bother with SIGTRAP in setup_rt_frame()
mn10300: don't bother with SIGTRAP in setup_frame()
frv: no need to raise SIGTRAP in setup_frame()
x86: get rid of duplicate code in case of CONFIG_VM86
unicore32: remove pointless test
h8300: trim _TIF_WORK_MASK
parisc: decide whether to go to slow path (tracesys) based on thread flags
parisc: don't bother looping in do_signal()
parisc: fix double restarts
bury the rest of TIF_IRET
sanitize tsk_is_polling()
bury _TIF_RESTORE_SIGMASK
unicore32: unobfuscate _TIF_WORK_MASK
mips: NOTIFY_RESUME is not needed in TIF masks
mips: merge the identical "return from syscall" per-ABI code
...
Conflicts:
arch/arm/include/asm/thread_info.h
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This include is no longer needed.
(seems to be a leftover from try_to_freeze())
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal
Pull generic execve() changes from Al Viro:
"This introduces the generic kernel_thread() and kernel_execve()
functions, and switches x86, arm, alpha, um and s390 over to them."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
s390: convert to generic kernel_execve()
s390: switch to generic kernel_thread()
s390: fold kernel_thread_helper() into ret_from_fork()
s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
um: switch to generic kernel_thread()
x86, um/x86: switch to generic sys_execve and kernel_execve
x86: split ret_from_fork
alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
alpha: switch to generic kernel_thread()
alpha: switch to generic sys_execve()
arm: get rid of execve wrapper, switch to generic execve() implementation
arm: optimized current_pt_regs()
arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
generic sys_execve()
generic kernel_execve()
new helper: current_pt_regs()
preparation for generic kernel_thread()
um: kill thread->forking
um: let signal_delivered() do SIGTRAP on singlestepping into handler
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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most of the architectures don't and there's not a single
caller outside of core kernel.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Pull ARM updates from Russell King:
"This is the first chunk of ARM updates for this merge window.
Conflicts are expected in two files - asm/timex.h and
mach-integrator/integrator_cp.c. Nothing particularly stands out more
than anything else.
Most of the growth is down to the opcodes stuff from Dave Martin,
which is countered by Rob's patches to use more of the asm-generic
headers on ARM."
(A few more conflicts grew since then, but it all looked fairly trivial)
* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (44 commits)
ARM: 7548/1: include linux/sched.h in syscall.h
ARM: 7541/1: Add ARM ERRATA 775420 workaround
ARM: ensure vm_struct has its phys_addr member filled in
ARM: 7540/1: kexec: Check segment memory addresses
ARM: 7539/1: kexec: scan for dtb magic in segments
ARM: 7538/1: delay: add registration mechanism for delay timer sources
ARM: 7536/1: smp: Formalize an IPI for wakeup
ARM: 7525/1: ptrace: use updated syscall number for syscall auditing
ARM: 7524/1: support syscall tracing
ARM: 7519/1: integrator: convert platform devices to Device Tree
ARM: 7518/1: integrator: convert AMBA devices to device tree
ARM: 7517/1: integrator: initial device tree support
ARM: 7516/1: plat-versatile: add DT support to FPGA IRQ
ARM: 7515/1: integrator: check PL010 base address from resource
ARM: 7514/1: integrator: call common init function from machine
ARM: 7522/1: arch_timers: register a time/cycle counter
ARM: 7523/1: arch_timers: enable the use of the virtual timer
ARM: 7531/1: mark kernelmode mem{cpy,set} non-experimental
ARM: 7520/1: Build dtb files in all target
ARM: Fix build warning in arch/arm/mm/alignment.c
...
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