/*
* CPU initialisation.
*/
static void hw_breakpoint_reset(void *unused)
{
int i;
struct perf_event **slots;
/*
* When a CPU goes through cold-boot, it does not have any installed
* slot, so it is safe to share the same function for restoring and
* resetting breakpoints; when a CPU is hotplugged in, it goes
* through the slots, which are all empty, hence it just resets control
* and value for debug registers.
* When this function is triggered on warm-boot through a CPU PM
* notifier some slots might be initialized; if so they are
* reprogrammed according to the debug slots content.
*/
for (slots = this_cpu_ptr(bp_on_reg), i = 0; i < core_num_brps; ++i) {
if (slots[i]) {
hw_breakpoint_control(slots[i], HW_BREAKPOINT_RESTORE);
} else {
write_wb_reg(AARCH64_DBG_REG_BCR, i, 0UL);
write_wb_reg(AARCH64_DBG_REG_BVR, i, 0UL);
}
}
for (slots = this_cpu_ptr(wp_on_reg), i = 0; i < core_num_wrps; ++i) {
if (slots[i]) {
hw_breakpoint_control(slots[i], HW_BREAKPOINT_RESTORE);
} else {
write_wb_reg(AARCH64_DBG_REG_WCR, i, 0UL);
write_wb_reg(AARCH64_DBG_REG_WVR, i, 0UL);
}
}
}
/*
* CPU initialisation.
*/
static void reset_ctrl_regs(void *unused)
{
int i;
for (i = 0; i < core_num_brps; ++i) {
write_wb_reg(AARCH64_DBG_REG_BCR, i, 0UL);
write_wb_reg(AARCH64_DBG_REG_BVR, i, 0UL);
}
for (i = 0; i < core_num_wrps; ++i) {
write_wb_reg(AARCH64_DBG_REG_WCR, i, 0UL);
write_wb_reg(AARCH64_DBG_REG_WVR, i, 0UL);
}
}
/*
* Install a perf counter breakpoint.
*/
int arch_install_hw_breakpoint(struct perf_event *bp)
{
struct arch_hw_breakpoint *info = counter_arch_bp(bp);
struct perf_event **slot, **slots;
struct debug_info *debug_info = ¤t->thread.debug;
int i, max_slots, ctrl_reg, val_reg, reg_enable;
u32 ctrl;
if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
/* Breakpoint */
ctrl_reg = AARCH64_DBG_REG_BCR;
val_reg = AARCH64_DBG_REG_BVR;
slots = __get_cpu_var(bp_on_reg);
max_slots = core_num_brps;
reg_enable = !debug_info->bps_disabled;
} else {
/* Watchpoint */
ctrl_reg = AARCH64_DBG_REG_WCR;
val_reg = AARCH64_DBG_REG_WVR;
slots = __get_cpu_var(wp_on_reg);
max_slots = core_num_wrps;
reg_enable = !debug_info->wps_disabled;
}
for (i = 0; i < max_slots; ++i) {
slot = &slots[i];
if (!*slot) {
*slot = bp;
break;
}
}
if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot"))
return -ENOSPC;
/* Ensure debug monitors are enabled at the correct exception level. */
enable_debug_monitors(debug_exception_level(info->ctrl.privilege));
/* Setup the address register. */
write_wb_reg(val_reg, i, info->address);
/* Setup the control register. */
ctrl = encode_ctrl_reg(info->ctrl);
write_wb_reg(ctrl_reg, i, reg_enable ? ctrl | 0x1 : ctrl & ~0x1);
return 0;
}
/*
* Enable/disable all of the breakpoints active at the specified
* exception level at the register level.
* This is used when single-stepping after a breakpoint exception.
*/
static void toggle_bp_registers(int reg, enum debug_el el, int enable)
{
int i, max_slots, privilege;
u32 ctrl;
struct perf_event **slots;
switch (reg) {
case AARCH64_DBG_REG_BCR:
slots = this_cpu_ptr(bp_on_reg);
max_slots = core_num_brps;
break;
case AARCH64_DBG_REG_WCR:
slots = this_cpu_ptr(wp_on_reg);
max_slots = core_num_wrps;
break;
default:
return;
}
for (i = 0; i < max_slots; ++i) {
if (!slots[i])
continue;
privilege = counter_arch_bp(slots[i])->ctrl.privilege;
if (debug_exception_level(privilege) != el)
continue;
ctrl = read_wb_reg(reg, i);
if (enable)
ctrl |= 0x1;
else
ctrl &= ~0x1;
write_wb_reg(reg, i, ctrl);
}
}
/*
* CPU initialisation.
*/
static void reset_ctrl_regs(void *unused)
{
#ifdef CONFIG_MEDIATEK_SOLUTION
/* mediatek will use our own operations for hw breakpoint/watchpoint */
#else
int i;
for (i = 0; i < core_num_brps; ++i) {
write_wb_reg(AARCH64_DBG_REG_BCR, i, 0UL);
write_wb_reg(AARCH64_DBG_REG_BVR, i, 0UL);
}
for (i = 0; i < core_num_wrps; ++i) {
write_wb_reg(AARCH64_DBG_REG_WCR, i, 0UL);
write_wb_reg(AARCH64_DBG_REG_WVR, i, 0UL);
}
#endif
}
static void hw_breakpoint_restore(void)
{
int i;
struct perf_event **slots;
for (slots = __get_cpu_var(bp_on_reg), i = 0; i < core_num_brps; ++i) {
if (slots[i]) {
hw_breakpoint_control(slots[i], HW_BREAKPOINT_RESTORE);
} else {
write_wb_reg(AARCH64_DBG_REG_BCR, i, 0UL);
write_wb_reg(AARCH64_DBG_REG_BVR, i, 0UL);
}
}
for (slots = __get_cpu_var(wp_on_reg), i = 0; i < core_num_wrps; ++i) {
if (slots[i]) {
hw_breakpoint_control(slots[i], HW_BREAKPOINT_RESTORE);
} else {
write_wb_reg(AARCH64_DBG_REG_WCR, i, 0UL);
write_wb_reg(AARCH64_DBG_REG_WVR, i, 0UL);
}
}
}
void arch_uninstall_hw_breakpoint(struct perf_event *bp)
{
struct arch_hw_breakpoint *info = counter_arch_bp(bp);
struct perf_event **slot, **slots;
int i, max_slots, base;
if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
/* Breakpoint */
base = AARCH64_DBG_REG_BCR;
slots = __get_cpu_var(bp_on_reg);
max_slots = core_num_brps;
} else {
/* Watchpoint */
base = AARCH64_DBG_REG_WCR;
slots = __get_cpu_var(wp_on_reg);
max_slots = core_num_wrps;
}
/* Remove the breakpoint. */
for (i = 0; i < max_slots; ++i) {
slot = &slots[i];
if (*slot == bp) {
*slot = NULL;
break;
}
}
if (WARN_ONCE(i == max_slots, "Can't find any breakpoint slot"))
return;
/* Reset the control register. */
write_wb_reg(base, i, 0);
/* Release the debug monitors for the correct exception level. */
disable_debug_monitors(debug_exception_level(info->ctrl.privilege));
}
static int hw_breakpoint_control(struct perf_event *bp,
enum hw_breakpoint_ops ops)
{
struct arch_hw_breakpoint *info = counter_arch_bp(bp);
struct perf_event **slots;
struct debug_info *debug_info = ¤t->thread.debug;
int i, max_slots, ctrl_reg, val_reg, reg_enable;
enum debug_el dbg_el = debug_exception_level(info->ctrl.privilege);
u32 ctrl;
if (info->ctrl.type == ARM_BREAKPOINT_EXECUTE) {
/* Breakpoint */
ctrl_reg = AARCH64_DBG_REG_BCR;
val_reg = AARCH64_DBG_REG_BVR;
slots = this_cpu_ptr(bp_on_reg);
max_slots = core_num_brps;
reg_enable = !debug_info->bps_disabled;
} else {
/* Watchpoint */
ctrl_reg = AARCH64_DBG_REG_WCR;
val_reg = AARCH64_DBG_REG_WVR;
slots = this_cpu_ptr(wp_on_reg);
max_slots = core_num_wrps;
reg_enable = !debug_info->wps_disabled;
}
i = hw_breakpoint_slot_setup(slots, max_slots, bp, ops);
if (WARN_ONCE(i < 0, "Can't find any breakpoint slot"))
return i;
switch (ops) {
case HW_BREAKPOINT_INSTALL:
/*
* Ensure debug monitors are enabled at the correct exception
* level.
*/
enable_debug_monitors(dbg_el);
/* Fall through */
case HW_BREAKPOINT_RESTORE:
/* Setup the address register. */
write_wb_reg(val_reg, i, info->address);
/* Setup the control register. */
ctrl = encode_ctrl_reg(info->ctrl);
write_wb_reg(ctrl_reg, i,
reg_enable ? ctrl | 0x1 : ctrl & ~0x1);
break;
case HW_BREAKPOINT_UNINSTALL:
/* Reset the control register. */
write_wb_reg(ctrl_reg, i, 0);
/*
* Release the debug monitors for the correct exception
* level.
*/
disable_debug_monitors(dbg_el);
break;
}
return 0;
}