diff options
| author | Will Deacon <will.deacon@arm.com> | 2011-02-25 20:20:42 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-02-26 13:35:51 +0000 |
| commit | c09bae709182046ab104757115dfbd74a1ba1a15 (patch) | |
| tree | 4abb05c23dd1846666c327d4ccb8aa3458b6f44a /arch | |
| parent | ba55d3db9bb59a52fe45dbc5d62776adbb289e54 (diff) | |
ARM: 6768/1: hw_breakpoint: ensure debug logic is powered up on v7 cores
ARMv7 allows the debug core logic to be powered down and provides the
DBGPRSR register so that software can power-up and check the status of
the logic.
This patch ensures that the debug logic is powered up on ARMv7 cores
before we attempt to access the extended debug registers.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index d600bd350704..44b84fe6e1b0 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -836,9 +836,11 @@ static int hw_breakpoint_pending(unsigned long addr, unsigned int fsr, /* * One-time initialisation. */ -static void reset_ctrl_regs(void *unused) +static void reset_ctrl_regs(void *info) { - int i; + int i, cpu = smp_processor_id(); + u32 dbg_power; + cpumask_t *cpumask = info; /* * v7 debug contains save and restore registers so that debug state @@ -850,6 +852,17 @@ static void reset_ctrl_regs(void *unused) */ if (debug_arch >= ARM_DEBUG_ARCH_V7_ECP14) { /* + * Ensure sticky power-down is clear (i.e. debug logic is + * powered up). + */ + asm volatile("mrc p14, 0, %0, c1, c5, 4" : "=r" (dbg_power)); + if ((dbg_power & 0x1) == 0) { + pr_warning("CPU %d debug is powered down!\n", cpu); + cpumask_or(cpumask, cpumask, cpumask_of(cpu)); + return; + } + + /* * Unconditionally clear the lock by writing a value * other than 0xC5ACCE55 to the access register. */ @@ -887,6 +900,7 @@ static struct notifier_block __cpuinitdata dbg_reset_nb = { static int __init arch_hw_breakpoint_init(void) { u32 dscr; + cpumask_t cpumask = { CPU_BITS_NONE }; debug_arch = get_debug_arch(); @@ -911,7 +925,13 @@ static int __init arch_hw_breakpoint_init(void) * Reset the breakpoint resources. We assume that a halting * debugger will leave the world in a nice state for us. */ - on_each_cpu(reset_ctrl_regs, NULL, 1); + on_each_cpu(reset_ctrl_regs, &cpumask, 1); + if (!cpumask_empty(&cpumask)) { + core_num_brps = 0; + core_num_reserved_brps = 0; + core_num_wrps = 0; + return 0; + } ARM_DBG_READ(c1, 0, dscr); if (dscr & ARM_DSCR_HDBGEN) { |