diff options
Diffstat (limited to 'arch/arm/kernel/hw_breakpoint.c')
| -rw-r--r-- | arch/arm/kernel/hw_breakpoint.c | 44 |
1 files changed, 26 insertions, 18 deletions
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c index c9f3f046757..d600bd35070 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -137,11 +137,10 @@ static u8 get_debug_arch(void) u32 didr; /* Do we implement the extended CPUID interface? */ - if (((read_cpuid_id() >> 16) & 0xf) != 0xf) { - pr_warning("CPUID feature registers not supported. " - "Assuming v6 debug is present.\n"); + if (WARN_ONCE((((read_cpuid_id() >> 16) & 0xf) != 0xf), + "CPUID feature registers not supported. " + "Assuming v6 debug is present.\n")) return ARM_DEBUG_ARCH_V6; - } ARM_DBG_READ(c0, 0, didr); return (didr >> 16) & 0xf; @@ -152,6 +151,12 @@ u8 arch_get_debug_arch(void) return debug_arch; } +static int debug_arch_supported(void) +{ + u8 arch = get_debug_arch(); + return arch >= ARM_DEBUG_ARCH_V6 && arch <= ARM_DEBUG_ARCH_V7_ECP14; +} + /* Determine number of BRP register available. */ static int get_num_brp_resources(void) { @@ -268,6 +273,9 @@ out: int hw_breakpoint_slots(int type) { + if (!debug_arch_supported()) + return 0; + /* * We can be called early, so don't rely on * our static variables being initialised. @@ -834,11 +842,11 @@ static void reset_ctrl_regs(void *unused) /* * v7 debug contains save and restore registers so that debug state - * can be maintained across low-power modes without leaving - * the debug logic powered up. It is IMPLEMENTATION DEFINED whether - * we can write to the debug registers out of reset, so we must - * unlock the OS Lock Access Register to avoid taking undefined - * instruction exceptions later on. + * can be maintained across low-power modes without leaving the debug + * logic powered up. It is IMPLEMENTATION DEFINED whether we can access + * the debug registers out of reset, so we must unlock the OS Lock + * Access Register to avoid taking undefined instruction exceptions + * later on. */ if (debug_arch >= ARM_DEBUG_ARCH_V7_ECP14) { /* @@ -882,7 +890,7 @@ static int __init arch_hw_breakpoint_init(void) debug_arch = get_debug_arch(); - if (debug_arch > ARM_DEBUG_ARCH_V7_ECP14) { + if (!debug_arch_supported()) { pr_info("debug architecture 0x%x unsupported.\n", debug_arch); return 0; } @@ -899,18 +907,18 @@ static int __init arch_hw_breakpoint_init(void) pr_info("%d breakpoint(s) reserved for watchpoint " "single-step.\n", core_num_reserved_brps); + /* + * 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); + ARM_DBG_READ(c1, 0, dscr); if (dscr & ARM_DSCR_HDBGEN) { + max_watchpoint_len = 4; pr_warning("halting debug mode enabled. Assuming maximum " - "watchpoint size of 4 bytes."); + "watchpoint size of %u bytes.", max_watchpoint_len); } else { - /* - * Reset the breakpoint resources. We assume that a halting - * debugger will leave the world in a nice state for us. - */ - smp_call_function(reset_ctrl_regs, NULL, 1); - reset_ctrl_regs(NULL); - /* Work out the maximum supported watchpoint length. */ max_watchpoint_len = get_max_wp_len(); pr_info("maximum watchpoint size is %u bytes.\n", |