/* Number of BRP/WRP registers on this CPU. */
static int core_num_brps;
-static int core_num_reserved_brps;
static int core_num_wrps;
/* Debug architecture version. */
u32 didr;
/* Do we implement the extended CPUID interface? */
- if (WARN_ONCE((((read_cpuid_id() >> 16) & 0xf) != 0xf),
- "CPUID feature registers not supported. "
- "Assuming v6 debug is present.\n"))
+ if (((read_cpuid_id() >> 16) & 0xf) != 0xf) {
+ pr_warning("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;
static int debug_arch_supported(void)
{
u8 arch = get_debug_arch();
- return arch >= ARM_DEBUG_ARCH_V6 && arch <= ARM_DEBUG_ARCH_V7_ECP14;
+
+ /* We don't support the memory-mapped interface. */
+ return (arch >= ARM_DEBUG_ARCH_V6 && arch <= ARM_DEBUG_ARCH_V7_ECP14) ||
+ arch >= ARM_DEBUG_ARCH_V7_1;
+}
+
+/* Determine number of WRP registers available. */
+static int get_num_wrp_resources(void)
+{
+ u32 didr;
+ ARM_DBG_READ(c0, 0, didr);
+ return ((didr >> 28) & 0xf) + 1;
}
-/* Determine number of BRP register available. */
+/* Determine number of BRP registers available. */
static int get_num_brp_resources(void)
{
u32 didr;
static int get_num_wrps(void)
{
/*
- * FIXME: When a watchpoint fires, the only way to work out which
- * watchpoint it was is by disassembling the faulting instruction
- * and working out the address of the memory access.
+ * On debug architectures prior to 7.1, when a watchpoint fires, the
+ * only way to work out which watchpoint it was is by disassembling
+ * the faulting instruction and working out the address of the memory
+ * access.
*
* Furthermore, we can only do this if the watchpoint was precise
* since imprecise watchpoints prevent us from calculating register
* [the ARM ARM states that the DFAR is UNKNOWN, but experience shows
* that it is set on some implementations].
*/
+ if (get_debug_arch() < ARM_DEBUG_ARCH_V7_1)
+ return 1;
-#if 0
- int wrps;
- u32 didr;
- ARM_DBG_READ(c0, 0, didr);
- wrps = ((didr >> 28) & 0xf) + 1;
-#endif
- int wrps = 1;
-
- if (core_has_mismatch_brps() && wrps >= get_num_brp_resources())
- wrps = get_num_brp_resources() - 1;
-
- return wrps;
-}
-
-/* We reserve one breakpoint for each watchpoint. */
-static int get_num_reserved_brps(void)
-{
- if (core_has_mismatch_brps())
- return get_num_wrps();
- return 0;
+ return get_num_wrp_resources();
}
/* Determine number of usable BRPs available. */
static int get_num_brps(void)
{
int brps = get_num_brp_resources();
- if (core_has_mismatch_brps())
- brps -= get_num_reserved_brps();
- return brps;
+ return core_has_mismatch_brps() ? brps - 1 : brps;
}
/*
/* Ensure that halting mode is disabled. */
if (WARN_ONCE(dscr & ARM_DSCR_HDBGEN,
- "halting debug mode enabled. Unable to access hardware resources.\n")) {
+ "halting debug mode enabled. Unable to access hardware resources.\n")) {
ret = -EPERM;
goto out;
}
ARM_DBG_WRITE(c1, 0, (dscr | ARM_DSCR_MDBGEN));
break;
case ARM_DEBUG_ARCH_V7_ECP14:
+ case ARM_DEBUG_ARCH_V7_1:
ARM_DBG_WRITE(c2, 2, (dscr | ARM_DSCR_MDBGEN));
break;
default:
val_base = ARM_BASE_BVR;
slots = (struct perf_event **)__get_cpu_var(bp_on_reg);
max_slots = core_num_brps;
- if (info->step_ctrl.enabled) {
- /* Override the breakpoint data with the step data. */
- addr = info->trigger & ~0x3;
- ctrl = encode_ctrl_reg(info->step_ctrl);
- }
} else {
/* Watchpoint */
- if (info->step_ctrl.enabled) {
- /* Install into the reserved breakpoint region. */
- ctrl_base = ARM_BASE_BCR + core_num_brps;
- val_base = ARM_BASE_BVR + core_num_brps;
- /* Override the watchpoint data with the step data. */
- addr = info->trigger & ~0x3;
- ctrl = encode_ctrl_reg(info->step_ctrl);
- } else {
- ctrl_base = ARM_BASE_WCR;
- val_base = ARM_BASE_WVR;
- }
+ ctrl_base = ARM_BASE_WCR;
+ val_base = ARM_BASE_WVR;
slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
max_slots = core_num_wrps;
}
goto out;
}
+ /* Override the breakpoint data with the step data. */
+ if (info->step_ctrl.enabled) {
+ addr = info->trigger & ~0x3;
+ ctrl = encode_ctrl_reg(info->step_ctrl);
+ if (info->ctrl.type != ARM_BREAKPOINT_EXECUTE) {
+ i = 0;
+ ctrl_base = ARM_BASE_BCR + core_num_brps;
+ val_base = ARM_BASE_BVR + core_num_brps;
+ }
+ }
+
/* Setup the address register. */
write_wb_reg(val_base + i, addr);
max_slots = core_num_brps;
} else {
/* Watchpoint */
- if (info->step_ctrl.enabled)
- base = ARM_BASE_BCR + core_num_brps;
- else
- base = ARM_BASE_WCR;
+ base = ARM_BASE_WCR;
slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
max_slots = core_num_wrps;
}
if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot\n"))
return;
+ /* Ensure that we disable the mismatch breakpoint. */
+ if (info->ctrl.type != ARM_BREAKPOINT_EXECUTE &&
+ info->step_ctrl.enabled) {
+ i = 0;
+ base = ARM_BASE_BCR + core_num_brps;
+ }
+
/* Reset the control register. */
write_wb_reg(base + i, 0);
}
* we can use the mismatch feature as a poor-man's hardware
* single-step, but this only works for per-task breakpoints.
*/
- if (WARN_ONCE(!bp->overflow_handler &&
- (arch_check_bp_in_kernelspace(bp) || !core_has_mismatch_brps()
- || !bp->hw.bp_target),
- "overflow handler required but none found\n")) {
+ if (!bp->overflow_handler && (arch_check_bp_in_kernelspace(bp) ||
+ !core_has_mismatch_brps() || !bp->hw.bp_target)) {
+ pr_warning("overflow handler required but none found\n");
ret = -EINVAL;
}
out:
arch_install_hw_breakpoint(bp);
}
-static void watchpoint_handler(unsigned long unknown, struct pt_regs *regs)
+static void watchpoint_handler(unsigned long addr, unsigned int fsr,
+ struct pt_regs *regs)
{
- int i;
+ int i, access;
+ u32 val, ctrl_reg, alignment_mask;
struct perf_event *wp, **slots;
struct arch_hw_breakpoint *info;
+ struct arch_hw_breakpoint_ctrl ctrl;
slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
- /* Without a disassembler, we can only handle 1 watchpoint. */
- BUG_ON(core_num_wrps > 1);
-
for (i = 0; i < core_num_wrps; ++i) {
rcu_read_lock();
wp = slots[i];
- if (wp == NULL) {
- rcu_read_unlock();
- continue;
- }
+ if (wp == NULL)
+ goto unlock;
+ info = counter_arch_bp(wp);
/*
- * The DFAR is an unknown value. Since we only allow a
- * single watchpoint, we can set the trigger to the lowest
- * possible faulting address.
+ * The DFAR is an unknown value on debug architectures prior
+ * to 7.1. Since we only allow a single watchpoint on these
+ * older CPUs, we can set the trigger to the lowest possible
+ * faulting address.
*/
- info = counter_arch_bp(wp);
- info->trigger = wp->attr.bp_addr;
+ if (debug_arch < ARM_DEBUG_ARCH_V7_1) {
+ BUG_ON(i > 0);
+ info->trigger = wp->attr.bp_addr;
+ } else {
+ if (info->ctrl.len == ARM_BREAKPOINT_LEN_8)
+ alignment_mask = 0x7;
+ else
+ alignment_mask = 0x3;
+
+ /* Check if the watchpoint value matches. */
+ val = read_wb_reg(ARM_BASE_WVR + i);
+ if (val != (addr & ~alignment_mask))
+ goto unlock;
+
+ /* Possible match, check the byte address select. */
+ ctrl_reg = read_wb_reg(ARM_BASE_WCR + i);
+ decode_ctrl_reg(ctrl_reg, &ctrl);
+ if (!((1 << (addr & alignment_mask)) & ctrl.len))
+ goto unlock;
+
+ /* Check that the access type matches. */
+ access = (fsr & ARM_FSR_ACCESS_MASK) ? HW_BREAKPOINT_W :
+ HW_BREAKPOINT_R;
+ if (!(access & hw_breakpoint_type(wp)))
+ goto unlock;
+
+ /* We have a winner. */
+ info->trigger = addr;
+ }
+
pr_debug("watchpoint fired: address = 0x%x\n", info->trigger);
perf_bp_event(wp, regs);
if (!wp->overflow_handler)
enable_single_step(wp, instruction_pointer(regs));
+unlock:
rcu_read_unlock();
}
}
slots = (struct perf_event **)__get_cpu_var(wp_on_reg);
- for (i = 0; i < core_num_reserved_brps; ++i) {
+ for (i = 0; i < core_num_wrps; ++i) {
rcu_read_lock();
wp = slots[i];
case ARM_ENTRY_ASYNC_WATCHPOINT:
WARN(1, "Asynchronous watchpoint exception taken. Debugging results may be unreliable\n");
case ARM_ENTRY_SYNC_WATCHPOINT:
- watchpoint_handler(addr, regs);
+ watchpoint_handler(addr, fsr, regs);
break;
default:
ret = 1; /* Unhandled fault. */
/*
* One-time initialisation.
*/
-static void reset_ctrl_regs(void *info)
+static cpumask_t debug_err_mask;
+
+static int debug_reg_trap(struct pt_regs *regs, unsigned int instr)
{
- int i, cpu = smp_processor_id();
+ int cpu = smp_processor_id();
+
+ pr_warning("Debug register access (0x%x) caused undefined instruction on CPU %d\n",
+ instr, cpu);
+
+ /* Set the error flag for this CPU and skip the faulting instruction. */
+ cpumask_set_cpu(cpu, &debug_err_mask);
+ instruction_pointer(regs) += 4;
+ return 0;
+}
+
+static struct undef_hook debug_reg_hook = {
+ .instr_mask = 0x0fe80f10,
+ .instr_val = 0x0e000e10,
+ .fn = debug_reg_trap,
+};
+
+static void reset_ctrl_regs(void *unused)
+{
+ int i, raw_num_brps, err = 0, cpu = smp_processor_id();
u32 dbg_power;
- cpumask_t *cpumask = info;
/*
* v7 debug contains save and restore registers so that debug state
* Access Register to avoid taking undefined instruction exceptions
* later on.
*/
- if (debug_arch >= ARM_DEBUG_ARCH_V7_ECP14) {
+ switch (debug_arch) {
+ case ARM_DEBUG_ARCH_V6:
+ case ARM_DEBUG_ARCH_V6_1:
+ /* ARMv6 cores just need to reset the registers. */
+ goto reset_regs;
+ case 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;
- }
-
+ if ((dbg_power & 0x1) == 0)
+ err = -EPERM;
+ break;
+ case ARM_DEBUG_ARCH_V7_1:
/*
- * Unconditionally clear the lock by writing a value
- * other than 0xC5ACCE55 to the access register.
+ * Ensure the OS double lock is clear.
*/
- asm volatile("mcr p14, 0, %0, c1, c0, 4" : : "r" (0));
- isb();
+ asm volatile("mrc p14, 0, %0, c1, c3, 4" : "=r" (dbg_power));
+ if ((dbg_power & 0x1) == 1)
+ err = -EPERM;
+ break;
+ }
- /*
- * Clear any configured vector-catch events before
- * enabling monitor mode.
- */
- asm volatile("mcr p14, 0, %0, c0, c7, 0" : : "r" (0));
- isb();
+ if (err) {
+ pr_warning("CPU %d debug is powered down!\n", cpu);
+ cpumask_or(&debug_err_mask, &debug_err_mask, cpumask_of(cpu));
+ return;
}
+ /*
+ * Unconditionally clear the lock by writing a value
+ * other than 0xC5ACCE55 to the access register.
+ */
+ asm volatile("mcr p14, 0, %0, c1, c0, 4" : : "r" (0));
+ isb();
+
+ /*
+ * Clear any configured vector-catch events before
+ * enabling monitor mode.
+ */
+ asm volatile("mcr p14, 0, %0, c0, c7, 0" : : "r" (0));
+ isb();
+
+reset_regs:
if (enable_monitor_mode())
return;
/* We must also reset any reserved registers. */
- for (i = 0; i < core_num_brps + core_num_reserved_brps; ++i) {
+ raw_num_brps = get_num_brp_resources();
+ for (i = 0; i < raw_num_brps; ++i) {
write_wb_reg(ARM_BASE_BCR + i, 0UL);
write_wb_reg(ARM_BASE_BVR + i, 0UL);
}
{
if (action == CPU_ONLINE)
smp_call_function_single((int)cpu, reset_ctrl_regs, NULL, 1);
+
return NOTIFY_OK;
}
static int __init arch_hw_breakpoint_init(void)
{
u32 dscr;
- cpumask_t cpumask = { CPU_BITS_NONE };
debug_arch = get_debug_arch();
/* Determine how many BRPs/WRPs are available. */
core_num_brps = get_num_brps();
- core_num_reserved_brps = get_num_reserved_brps();
core_num_wrps = get_num_wrps();
- pr_info("found %d breakpoint and %d watchpoint registers.\n",
- core_num_brps + core_num_reserved_brps, core_num_wrps);
-
- if (core_num_reserved_brps)
- pr_info("%d breakpoint(s) reserved for watchpoint "
- "single-step.\n", core_num_reserved_brps);
+ /*
+ * We need to tread carefully here because DBGSWENABLE may be
+ * driven low on this core and there isn't an architected way to
+ * determine that.
+ */
+ register_undef_hook(&debug_reg_hook);
/*
* 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, &cpumask, 1);
- if (!cpumask_empty(&cpumask)) {
+ on_each_cpu(reset_ctrl_regs, NULL, 1);
+ unregister_undef_hook(&debug_reg_hook);
+ if (!cpumask_empty(&debug_err_mask)) {
core_num_brps = 0;
- core_num_reserved_brps = 0;
core_num_wrps = 0;
return 0;
}
+ pr_info("found %d " "%s" "breakpoint and %d watchpoint registers.\n",
+ core_num_brps, core_has_mismatch_brps() ? "(+1 reserved) " :
+ "", core_num_wrps);
+
ARM_DBG_READ(c1, 0, dscr);
if (dscr & ARM_DSCR_HDBGEN) {
max_watchpoint_len = 4;
git.openpandora.org / pandora-kernel.git / blobdiff