diff options
author | Will Deacon <will.deacon@arm.com> | 2010-11-24 17:45:49 (GMT) |
---|---|---|
committer | Will Deacon <will.deacon@arm.com> | 2010-12-06 11:55:56 (GMT) |
commit | 7d99331e4793b52d488e911876ef11d843c6c8c9 (patch) | |
tree | 0b9d7e659ed21a56c166303772043afcdf9da61a /arch/arm/kernel/hw_breakpoint.c | |
parent | ac88e07122fc0eb5cbad403be97ef02c317a06b7 (diff) | |
download | linux-7d99331e4793b52d488e911876ef11d843c6c8c9.tar.xz |
ARM: hw_breakpoint: reset control registers in hotplug path
The ARMv7 debug architecture doesn't make any guarantees about the
contents of debug control registers following a debug logic reset.
This patch ensures that we reset the control registers when a cpu
comes ONLINE (for example, with hotplug) so that when we enable
monitor mode while inserting a breakpoint we won't exhibit random
behaviour.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch/arm/kernel/hw_breakpoint.c')
-rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 16 |
1 files changed, 15 insertions, 1 deletions
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index 793959e..515a3c4 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -764,7 +764,7 @@ out: /* * One-time initialisation. */ -static void __init reset_ctrl_regs(void *unused) +static void reset_ctrl_regs(void *unused) { int i; @@ -799,6 +799,18 @@ static void __init reset_ctrl_regs(void *unused) } } +static int __cpuinit dbg_reset_notify(struct notifier_block *self, + unsigned long action, void *cpu) +{ + if (action == CPU_ONLINE) + smp_call_function_single((int)cpu, reset_ctrl_regs, NULL, 1); + return NOTIFY_OK; +} + +static struct notifier_block __cpuinitdata dbg_reset_nb = { + .notifier_call = dbg_reset_notify, +}; + static int __init arch_hw_breakpoint_init(void) { int ret = 0; @@ -846,6 +858,8 @@ static int __init arch_hw_breakpoint_init(void) hook_ifault_code(2, hw_breakpoint_pending, SIGTRAP, TRAP_HWBKPT, "breakpoint debug exception"); + /* Register hotplug notifier. */ + register_cpu_notifier(&dbg_reset_nb); out: return ret; } |