linux/arch/arm/kernel
Javier Martinez Canillas c5dff4ffd3 ARM: 7480/1: only call smp_send_stop() on SMP
On reboot or poweroff (machine_shutdown()) a call to smp_send_stop() is
made (to stop the others CPU's) when CONFIG_SMP=y.

arch/arm/kernel/process.c:

void machine_shutdown(void)
{
 #ifdef CONFIG_SMP
       smp_send_stop();
 #endif
}

smp_send_stop() calls the function pointer smp_cross_call(), which is set
on the smp_init_cpus() function for OMAP processors.

arch/arm/mach-omap2/omap-smp.c:

void __init smp_init_cpus(void)
{
...
	set_smp_cross_call(gic_raise_softirq);
...
}

But the ARM setup_arch() function only calls smp_init_cpus()
if CONFIG_SMP=y && is_smp().

arm/kernel/setup.c:

void __init setup_arch(char **cmdline_p)
{
...
 #ifdef CONFIG_SMP
	if (is_smp())
		smp_init_cpus();
 #endif
...
}

Newer OMAP CPU's are SMP machines so omap2plus_defconfig sets
CONFIG_SMP=y. Unfortunately on an OMAP UP machine is_smp()
returns false and smp_init_cpus() is never called and the
smp_cross_call() function remains NULL.

If the machine is rebooted or powered off, smp_send_stop() will
be called (since CONFIG_SMP=y) leading to the following error:

[   42.815551] Restarting system.
[   42.819030] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   42.827667] pgd = d7a74000
[   42.830566] [00000000] *pgd=96ce7831, *pte=00000000, *ppte=00000000
[   42.837249] Internal error: Oops: 80000007 [#1] SMP ARM
[   42.842773] Modules linked in:
[   42.846008] CPU: 0    Not tainted  (3.5.0-rc3-next-20120622-00002-g62e87ba-dirty #44)
[   42.854278] PC is at 0x0
[   42.856994] LR is at smp_send_stop+0x4c/0xe4
[   42.861511] pc : [<00000000>]    lr : [<c00183a4>]    psr: 60000013
[   42.861511] sp : d6c85e70  ip : 00000000  fp : 00000000
[   42.873626] r10: 00000000  r9 : d6c84000  r8 : 00000002
[   42.879150] r7 : c07235a0  r6 : c06dd2d0  r5 : 000f4241  r4 : d6c85e74
[   42.886047] r3 : 00000000  r2 : 00000000  r1 : 00000006  r0 : d6c85e74
[   42.892944] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   42.900482] Control: 10c5387d  Table: 97a74019  DAC: 00000015
[   42.906555] Process reboot (pid: 1166, stack limit = 0xd6c842f8)
[   42.912902] Stack: (0xd6c85e70 to 0xd6c86000)
[   42.917510] 5e60:                                     c07235a0 00000000 00000000 d6c84000
[   42.926177] 5e80: 01234567 c00143d0 4321fedc c00511bc d6c85ebc 00000168 00000460 00000000
[   42.934814] 5ea0: c1017950 a0000013 c1017900 d8014390 d7ec3858 c0498e48 c1017950 00000000
[   42.943481] 5ec0: d6ddde10 d6c85f78 00000003 00000000 d6ddde10 d6c84000 00000000 00000000
[   42.952117] 5ee0: 00000002 00000000 00000000 c0088c88 00000002 00000000 00000000 c00f4b90
[   42.960784] 5f00: 00000000 d6c85ebc d8014390 d7e311c8 60000013 00000103 00000002 d6c84000
[   42.969421] 5f20: c00f3274 d6e00a00 00000001 60000013 d6c84000 00000000 00000000 c00895d4
[   42.978057] 5f40: 00000002 d8007c80 d781f000 c00f6150 d8010cc0 c00f3274 d781f000 d6c84000
[   42.986694] 5f60: c0013020 d6e00a00 00000001 20000010 0001257c ef000000 00000000 c00895d4
[   42.995361] 5f80: 00000002 00000001 00000003 00000000 00000001 00000003 00000000 00000058
[   43.003997] 5fa0: c00130c8 c0012f00 00000001 00000003 fee1dead 28121969 01234567 00000002
[   43.012634] 5fc0: 00000001 00000003 00000000 00000058 00012584 0001257c 00000001 00000000
[   43.021270] 5fe0: 000124bc bec5cc6c 00008f9c 4a2f7c40 20000010 fee1dead 00000000 00000000
[   43.029968] [<c00183a4>] (smp_send_stop+0x4c/0xe4) from [<c00143d0>] (machine_restart+0xc/0x4c)
[   43.039154] [<c00143d0>] (machine_restart+0xc/0x4c) from [<c00511bc>] (sys_reboot+0x144/0x1f0)
[   43.048278] [<c00511bc>] (sys_reboot+0x144/0x1f0) from [<c0012f00>] (ret_fast_syscall+0x0/0x3c)
[   43.057464] Code: bad PC value
[   43.060760] ---[ end trace c3988d1dd0b8f0fb ]---

Add a check so smp_cross_call() is only called when there is more than one CPU on-line.

Cc: <stable@vger.kernel.org>
Signed-off-by: Javier Martinez Canillas <javier at dowhile0.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-07-31 10:30:44 +01:00
..
.gitignore
arch_timer.c ARM: architected timers: remove support for non DT platforms 2012-04-27 13:39:25 +01:00
armksyms.c Disintegrate asm/system.h for ARM 2012-03-28 18:30:01 +01:00
arthur.c
asm-offsets.c ARM: 7114/1: cache-l2x0: add resume entry for l2 in secure mode 2011-10-17 09:11:51 +01:00
atags.c
atags.h
bios32.c ARM: PCI: remove per-pci_hw list of buses 2012-05-16 15:24:12 +01:00
calls.S ARM: wire up process_vm_writev and process_vm_readv syscalls 2011-11-17 16:58:00 +00:00
compat.c
compat.h
cpuidle.c cpuidle: Add common time keeping and irq enabling 2012-03-21 01:59:40 -04:00
crash_dump.c
debug.S ARM: cleanups of io includes 2012-03-29 18:02:10 -07:00
devtree.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
dma-isa.c
dma.c locking, ARM: Annotate low level hw locks as raw 2011-09-13 11:12:14 +02:00
early_printk.c
elf.c Disintegrate asm/system.h for ARM 2012-03-28 18:30:01 +01:00
entry-armv.S ARM: 7425/1: extable: ensure fixup entries are 4-byte aligned 2012-06-16 16:30:25 +01:00
entry-common.S Merge branch 'for-arm' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal.git into for-linus 2012-05-29 22:13:55 +01:00
entry-header.S Merge branch 'devel-stable' into for-next 2011-07-22 23:09:07 +01:00
etm.c arm: fix implicit module.h users by adding it to arch/arm as required. 2011-10-31 19:30:50 -04:00
fiq.c ARM: move CP15 definitions to separate header file 2012-03-28 18:30:01 +01:00
fiqasm.S ARM: 6938/1: fiq: Refactor {get,set}_fiq_regs() for Thumb-2 2011-05-26 10:31:06 +01:00
ftrace.c ARM: 7468/1: ftrace: Trace function entry before updating index 2012-07-31 10:30:42 +01:00
head-common.S arm/dt: Make __vet_atags also accept a dtb image 2011-05-11 15:12:32 +02:00
head-nommu.S ARM: move CP15 definitions to separate header file 2012-03-28 18:30:01 +01:00
head.S ARM: 7363/1: DEBUG_LL: limit early mapping to the minimum 2012-05-04 16:56:46 +01:00
hw_breakpoint.c Disintegrate asm/system.h for ARM 2012-03-28 18:30:01 +01:00
insn.c ARM: fix missing bug.h include in arch/arm/kernel/insn.c 2012-03-30 11:51:46 +01:00
insn.h ARM: 7334/1: add jump label support 2012-03-24 09:38:56 +00:00
io.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
irq.c ARM: 7406/1: hotplug: copy the affinity mask when forcefully migrating IRQs 2012-04-28 11:01:31 +01:00
isa.c
iwmmxt.S ARM: pxa: fix logic error in PJ4 iWMMXt handling 2011-08-11 10:10:26 +08:00
jump_label.c ARM: 7334/1: add jump label support 2012-03-24 09:38:56 +00:00
kgdb.c
kprobes-arm.c ARM: 7181/1: Restrict kprobes probing SWP instructions to ARMv5 and below 2011-11-30 23:54:54 +00:00
kprobes-common.c Disintegrate asm/system.h for ARM 2012-03-28 18:30:01 +01:00
kprobes-test-arm.c ARM: 7440/1: kprobes: only test 'sub pc, pc, #1b-2b+8-2' on ARMv6 2012-07-05 12:57:16 +01:00
kprobes-test-thumb.c ARM: 7174/1: Fix build error in kprobes test code on Thumb2 kernels 2011-11-26 21:58:53 +00:00
kprobes-test.c ARM: 7209/1: Use generic ARM instruction set condition code checks for kprobes. 2011-12-13 08:52:03 +00:00
kprobes-test.h ARM: 7174/1: Fix build error in kprobes test code on Thumb2 kernels 2011-11-26 21:58:53 +00:00
kprobes-thumb.c ARM: 7423/1: kprobes: run t32_simulate_ldr_literal() without insn slot 2012-06-14 15:11:44 +01:00
kprobes.c Autogenerated GPG tag for Rusty D1ADB8F1: 15EE 8D6C AB0E 7F0C F999 BFCB D920 0E6C D1AD B8F1 2012-04-02 08:53:24 -07:00
kprobes.h ARM: kprobes: Add exports for test code 2011-09-20 18:17:43 +00:00
leds.c arm: leds: convert sysdev_class to a regular subsystem 2011-12-21 15:52:57 -08:00
machine_kexec.c Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm 2012-03-29 16:53:48 -07:00
Makefile Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-05-21 19:43:57 -07:00
module.c ARM: 7059/1: LPAE: Use PMD_(SHIFT|SIZE|MASK) instead of PGDIR_* 2011-08-23 15:30:33 +01:00
opcodes.c ARM: 7206/1: Add generic ARM instruction set condition code checks. 2011-12-13 08:52:02 +00:00
patch.c ARM: 7332/1: extract out code patch function from kprobes 2012-03-24 09:38:55 +00:00
patch.h ARM: 7332/1: extract out code patch function from kprobes 2012-03-24 09:38:55 +00:00
perf_event_v6.c perf: Pass last sampling period to perf_sample_data_init() 2012-05-09 15:23:12 +02:00
perf_event_v7.c perf: Pass last sampling period to perf_sample_data_init() 2012-05-09 15:23:12 +02:00
perf_event_xscale.c perf: Pass last sampling period to perf_sample_data_init() 2012-05-09 15:23:12 +02:00
perf_event.c ARM: 7441/1: perf: return -EOPNOTSUPP if requested mode exclusion is unavailable 2012-07-05 09:50:56 +01:00
pj4-cp0.c arm: remove several unnecessary module.h include instances 2011-10-31 19:30:48 -04:00
pmu.c ARM: PMU: re-export release_pmu symbol to modules 2011-11-16 10:06:42 +00:00
process.c ARM: 7466/1: disable interrupt before spinning endlessly 2012-07-31 10:30:31 +01:00
ptrace.c ARM: 7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK" 2012-07-05 09:50:56 +01:00
relocate_kernel.S ARM: 7065/1: kexec: ensure new kernel is entered in ARM state 2011-08-28 10:39:41 +01:00
return_address.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
sched_clock.c ARM: sync sched_clock() state on suspend 2012-03-24 09:38:53 +00:00
setup.c ARM: 7465/1: Handle >4GB memory sizes in device tree and mem=size@start option 2012-07-29 22:19:14 +01:00
signal.c ARM: 7443/1: Revert "new way of handling ERESTART_RESTARTBLOCK" 2012-07-05 09:50:56 +01:00
signal.h ARM: 7442/1: Revert "remove unused restart trampoline" 2012-07-05 09:50:56 +01:00
sleep.S Disintegrate asm/system.h for ARM 2012-03-28 18:30:01 +01:00
smp_scu.c ARM: 7347/1: SCU: use cpu_logical_map for per-CPU low power mode 2012-04-28 17:31:37 +01:00
smp_tlb.c smp: introduce a generic on_each_cpu_mask() function 2012-03-28 17:14:35 -07:00
smp_twd.c Revert "ARM: 7359/2: smp_twd: Only wait for reprogramming on active cpus" 2012-04-19 19:35:10 +01:00
smp.c ARM: 7480/1: only call smp_send_stop() on SMP 2012-07-31 10:30:44 +01:00
stacktrace.c arm: convert core files from module.h to export.h 2011-10-31 19:30:49 -04:00
suspend.c ARM: suspend: use idmap_pgd instead of suspend_pgd 2011-12-06 14:04:14 +00:00
swp_emulate.c ARM: 7208/1: Add condition code checking to SWP emulation handler. 2011-12-13 08:52:03 +00:00
sys_arm.c ARM: 7410/1: Add extra clobber registers for assembly in kernel_execve 2012-05-05 13:54:01 +01:00
sys_oabi-compat.c userns: Convert stat to return values mapped from kuids and kgids 2012-05-15 14:08:35 -07:00
tcm.c Disintegrate asm/system.h for ARM 2012-03-28 18:30:01 +01:00
tcm.h
thumbee.c ARM: 7385/1: ThumbEE: Use cpuid macros to read ID_PFR0 for ThumbEE 2012-04-25 19:49:26 +01:00
time.c ARM: 7413/1: move read_{boot,persistent}_clock to the architecture level 2012-05-06 11:09:21 +01:00
topology.c ARM: 7182/1: ARM cpu topology: fix warning 2011-11-30 23:55:21 +00:00
traps.c ARM: 7442/1: Revert "remove unused restart trampoline" 2012-07-05 09:50:56 +01:00
unwind.c ARM: unwinder: fix bisection to find origin in .idx section 2011-12-15 14:02:19 -08:00
vmlinux.lds.S ARM: 7428/1: Prevent KALLSYM size mismatch on ARM. 2012-06-22 22:54:18 +01:00
xscale-cp0.c arm: remove several unnecessary module.h include instances 2011-10-31 19:30:48 -04:00