--- /dev/null
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_HW_BREAKPOINT_H
+#define __ASM_HW_BREAKPOINT_H
+
+#include <asm/loongarch.h>
+
+#ifdef __KERNEL__
+
+/* Breakpoint */
+#define LOONGARCH_BREAKPOINT_EXECUTE (0 << 0)
+
+/* Watchpoints */
+#define LOONGARCH_BREAKPOINT_LOAD (1 << 0)
+#define LOONGARCH_BREAKPOINT_STORE (1 << 1)
+
+struct arch_hw_breakpoint_ctrl {
+ u32 __reserved : 28,
+ len : 2,
+ type : 2;
+};
+
+struct arch_hw_breakpoint {
+ u64 address;
+ u64 mask;
+ struct arch_hw_breakpoint_ctrl ctrl;
+};
+
+/* Lengths */
+#define LOONGARCH_BREAKPOINT_LEN_1 0b11
+#define LOONGARCH_BREAKPOINT_LEN_2 0b10
+#define LOONGARCH_BREAKPOINT_LEN_4 0b01
+#define LOONGARCH_BREAKPOINT_LEN_8 0b00
+
+/*
+ * Limits.
+ * Changing these will require modifications to the register accessors.
+ */
+#define LOONGARCH_MAX_BRP 8
+#define LOONGARCH_MAX_WRP 8
+
+/* Virtual debug register bases. */
+#define CSR_CFG_ADDR 0
+#define CSR_CFG_MASK (CSR_CFG_ADDR + LOONGARCH_MAX_BRP)
+#define CSR_CFG_CTRL (CSR_CFG_MASK + LOONGARCH_MAX_BRP)
+#define CSR_CFG_ASID (CSR_CFG_CTRL + LOONGARCH_MAX_WRP)
+
+/* Debug register names. */
+#define LOONGARCH_CSR_NAME_ADDR ADDR
+#define LOONGARCH_CSR_NAME_MASK MASK
+#define LOONGARCH_CSR_NAME_CTRL CTRL
+#define LOONGARCH_CSR_NAME_ASID ASID
+
+/* Accessor macros for the debug registers. */
+#define LOONGARCH_CSR_WATCH_READ(N, REG, T, VAL) \
+do { \
+ if (T == 0) \
+ VAL = csr_read64(LOONGARCH_CSR_##IB##N##REG); \
+ else \
+ VAL = csr_read64(LOONGARCH_CSR_##DB##N##REG); \
+} while (0)
+
+#define LOONGARCH_CSR_WATCH_WRITE(N, REG, T, VAL) \
+do { \
+ if (T == 0) \
+ csr_write64(VAL, LOONGARCH_CSR_##IB##N##REG); \
+ else \
+ csr_write64(VAL, LOONGARCH_CSR_##DB##N##REG); \
+} while (0)
+
+/* Exact number */
+#define CSR_FWPC_NUM 0x3f
+#define CSR_MWPC_NUM 0x3f
+
+#define CTRL_PLV_ENABLE 0x1e
+
+#define MWPnCFG3_LoadEn 8
+#define MWPnCFG3_StoreEn 9
+
+#define MWPnCFG3_Type_mask 0x3
+#define MWPnCFG3_Size_mask 0x3
+
+static inline u32 encode_ctrl_reg(struct arch_hw_breakpoint_ctrl ctrl)
+{
+ return (ctrl.len << 10) | (ctrl.type << 8);
+}
+
+static inline void decode_ctrl_reg(u32 reg, struct arch_hw_breakpoint_ctrl *ctrl)
+{
+ reg >>= 8;
+ ctrl->type = reg & MWPnCFG3_Type_mask;
+ reg >>= 2;
+ ctrl->len = reg & MWPnCFG3_Size_mask;
+}
+
+struct task_struct;
+struct notifier_block;
+struct perf_event;
+struct perf_event_attr;
+
+extern int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
+ int *gen_len, int *gen_type, int *offset);
+extern int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw);
+extern int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw);
+extern int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
+ unsigned long val, void *data);
+
+extern int arch_install_hw_breakpoint(struct perf_event *bp);
+extern void arch_uninstall_hw_breakpoint(struct perf_event *bp);
+extern int hw_breakpoint_slots(int type);
+extern void hw_breakpoint_pmu_read(struct perf_event *bp);
+
+void breakpoint_handler(struct pt_regs *regs);
+void watchpoint_handler(struct pt_regs *regs);
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+extern void ptrace_hw_copy_thread(struct task_struct *task);
+extern void hw_breakpoint_thread_switch(struct task_struct *next);
+#else
+static inline void ptrace_hw_copy_thread(struct task_struct *task)
+{
+}
+static inline void hw_breakpoint_thread_switch(struct task_struct *next)
+{
+}
+#endif
+
+/* Determine number of BRP registers available. */
+static inline int get_num_brps(void)
+{
+ return csr_read64(LOONGARCH_CSR_FWPC) & CSR_FWPC_NUM;
+}
+
+/* Determine number of WRP registers available. */
+static inline int get_num_wrps(void)
+{
+ return csr_read64(LOONGARCH_CSR_MWPC) & CSR_MWPC_NUM;
+}
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_BREAKPOINT_H */
#define LOONGARCH_CSR_DB0ADDR 0x310 /* data breakpoint 0 address */
#define LOONGARCH_CSR_DB0MASK 0x311 /* data breakpoint 0 mask */
-#define LOONGARCH_CSR_DB0CTL 0x312 /* data breakpoint 0 control */
+#define LOONGARCH_CSR_DB0CTRL 0x312 /* data breakpoint 0 control */
#define LOONGARCH_CSR_DB0ASID 0x313 /* data breakpoint 0 asid */
#define LOONGARCH_CSR_DB1ADDR 0x318 /* data breakpoint 1 address */
#define LOONGARCH_CSR_DB1MASK 0x319 /* data breakpoint 1 mask */
-#define LOONGARCH_CSR_DB1CTL 0x31a /* data breakpoint 1 control */
+#define LOONGARCH_CSR_DB1CTRL 0x31a /* data breakpoint 1 control */
#define LOONGARCH_CSR_DB1ASID 0x31b /* data breakpoint 1 asid */
#define LOONGARCH_CSR_DB2ADDR 0x320 /* data breakpoint 2 address */
#define LOONGARCH_CSR_DB2MASK 0x321 /* data breakpoint 2 mask */
-#define LOONGARCH_CSR_DB2CTL 0x322 /* data breakpoint 2 control */
+#define LOONGARCH_CSR_DB2CTRL 0x322 /* data breakpoint 2 control */
#define LOONGARCH_CSR_DB2ASID 0x323 /* data breakpoint 2 asid */
#define LOONGARCH_CSR_DB3ADDR 0x328 /* data breakpoint 3 address */
#define LOONGARCH_CSR_DB3MASK 0x329 /* data breakpoint 3 mask */
-#define LOONGARCH_CSR_DB3CTL 0x32a /* data breakpoint 3 control */
+#define LOONGARCH_CSR_DB3CTRL 0x32a /* data breakpoint 3 control */
#define LOONGARCH_CSR_DB3ASID 0x32b /* data breakpoint 3 asid */
#define LOONGARCH_CSR_DB4ADDR 0x330 /* data breakpoint 4 address */
#define LOONGARCH_CSR_DB4MASK 0x331 /* data breakpoint 4 maks */
-#define LOONGARCH_CSR_DB4CTL 0x332 /* data breakpoint 4 control */
+#define LOONGARCH_CSR_DB4CTRL 0x332 /* data breakpoint 4 control */
#define LOONGARCH_CSR_DB4ASID 0x333 /* data breakpoint 4 asid */
#define LOONGARCH_CSR_DB5ADDR 0x338 /* data breakpoint 5 address */
#define LOONGARCH_CSR_DB5MASK 0x339 /* data breakpoint 5 mask */
-#define LOONGARCH_CSR_DB5CTL 0x33a /* data breakpoint 5 control */
+#define LOONGARCH_CSR_DB5CTRL 0x33a /* data breakpoint 5 control */
#define LOONGARCH_CSR_DB5ASID 0x33b /* data breakpoint 5 asid */
#define LOONGARCH_CSR_DB6ADDR 0x340 /* data breakpoint 6 address */
#define LOONGARCH_CSR_DB6MASK 0x341 /* data breakpoint 6 mask */
-#define LOONGARCH_CSR_DB6CTL 0x342 /* data breakpoint 6 control */
+#define LOONGARCH_CSR_DB6CTRL 0x342 /* data breakpoint 6 control */
#define LOONGARCH_CSR_DB6ASID 0x343 /* data breakpoint 6 asid */
#define LOONGARCH_CSR_DB7ADDR 0x348 /* data breakpoint 7 address */
#define LOONGARCH_CSR_DB7MASK 0x349 /* data breakpoint 7 mask */
-#define LOONGARCH_CSR_DB7CTL 0x34a /* data breakpoint 7 control */
+#define LOONGARCH_CSR_DB7CTRL 0x34a /* data breakpoint 7 control */
#define LOONGARCH_CSR_DB7ASID 0x34b /* data breakpoint 7 asid */
#define LOONGARCH_CSR_FWPC 0x380 /* instruction breakpoint config */
#define LOONGARCH_CSR_IB0ADDR 0x390 /* inst breakpoint 0 address */
#define LOONGARCH_CSR_IB0MASK 0x391 /* inst breakpoint 0 mask */
-#define LOONGARCH_CSR_IB0CTL 0x392 /* inst breakpoint 0 control */
+#define LOONGARCH_CSR_IB0CTRL 0x392 /* inst breakpoint 0 control */
#define LOONGARCH_CSR_IB0ASID 0x393 /* inst breakpoint 0 asid */
#define LOONGARCH_CSR_IB1ADDR 0x398 /* inst breakpoint 1 address */
#define LOONGARCH_CSR_IB1MASK 0x399 /* inst breakpoint 1 mask */
-#define LOONGARCH_CSR_IB1CTL 0x39a /* inst breakpoint 1 control */
+#define LOONGARCH_CSR_IB1CTRL 0x39a /* inst breakpoint 1 control */
#define LOONGARCH_CSR_IB1ASID 0x39b /* inst breakpoint 1 asid */
#define LOONGARCH_CSR_IB2ADDR 0x3a0 /* inst breakpoint 2 address */
#define LOONGARCH_CSR_IB2MASK 0x3a1 /* inst breakpoint 2 mask */
-#define LOONGARCH_CSR_IB2CTL 0x3a2 /* inst breakpoint 2 control */
+#define LOONGARCH_CSR_IB2CTRL 0x3a2 /* inst breakpoint 2 control */
#define LOONGARCH_CSR_IB2ASID 0x3a3 /* inst breakpoint 2 asid */
#define LOONGARCH_CSR_IB3ADDR 0x3a8 /* inst breakpoint 3 address */
#define LOONGARCH_CSR_IB3MASK 0x3a9 /* breakpoint 3 mask */
-#define LOONGARCH_CSR_IB3CTL 0x3aa /* inst breakpoint 3 control */
+#define LOONGARCH_CSR_IB3CTRL 0x3aa /* inst breakpoint 3 control */
#define LOONGARCH_CSR_IB3ASID 0x3ab /* inst breakpoint 3 asid */
#define LOONGARCH_CSR_IB4ADDR 0x3b0 /* inst breakpoint 4 address */
#define LOONGARCH_CSR_IB4MASK 0x3b1 /* inst breakpoint 4 mask */
-#define LOONGARCH_CSR_IB4CTL 0x3b2 /* inst breakpoint 4 control */
+#define LOONGARCH_CSR_IB4CTRL 0x3b2 /* inst breakpoint 4 control */
#define LOONGARCH_CSR_IB4ASID 0x3b3 /* inst breakpoint 4 asid */
#define LOONGARCH_CSR_IB5ADDR 0x3b8 /* inst breakpoint 5 address */
#define LOONGARCH_CSR_IB5MASK 0x3b9 /* inst breakpoint 5 mask */
-#define LOONGARCH_CSR_IB5CTL 0x3ba /* inst breakpoint 5 control */
+#define LOONGARCH_CSR_IB5CTRL 0x3ba /* inst breakpoint 5 control */
#define LOONGARCH_CSR_IB5ASID 0x3bb /* inst breakpoint 5 asid */
#define LOONGARCH_CSR_IB6ADDR 0x3c0 /* inst breakpoint 6 address */
#define LOONGARCH_CSR_IB6MASK 0x3c1 /* inst breakpoint 6 mask */
-#define LOONGARCH_CSR_IB6CTL 0x3c2 /* inst breakpoint 6 control */
+#define LOONGARCH_CSR_IB6CTRL 0x3c2 /* inst breakpoint 6 control */
#define LOONGARCH_CSR_IB6ASID 0x3c3 /* inst breakpoint 6 asid */
#define LOONGARCH_CSR_IB7ADDR 0x3c8 /* inst breakpoint 7 address */
#define LOONGARCH_CSR_IB7MASK 0x3c9 /* inst breakpoint 7 mask */
-#define LOONGARCH_CSR_IB7CTL 0x3ca /* inst breakpoint 7 control */
+#define LOONGARCH_CSR_IB7CTRL 0x3ca /* inst breakpoint 7 control */
#define LOONGARCH_CSR_IB7ASID 0x3cb /* inst breakpoint 7 asid */
#define LOONGARCH_CSR_DEBUG 0x500 /* debug config */
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022-2023 Loongson Technology Corporation Limited
+ */
+#define pr_fmt(fmt) "hw-breakpoint: " fmt
+
+#include <linux/hw_breakpoint.h>
+#include <linux/kprobes.h>
+#include <linux/perf_event.h>
+
+#include <asm/hw_breakpoint.h>
+
+/* Breakpoint currently in use for each BRP. */
+static DEFINE_PER_CPU(struct perf_event *, bp_on_reg[LOONGARCH_MAX_BRP]);
+
+/* Watchpoint currently in use for each WRP. */
+static DEFINE_PER_CPU(struct perf_event *, wp_on_reg[LOONGARCH_MAX_WRP]);
+
+int hw_breakpoint_slots(int type)
+{
+ /*
+ * We can be called early, so don't rely on
+ * our static variables being initialised.
+ */
+ switch (type) {
+ case TYPE_INST:
+ return get_num_brps();
+ case TYPE_DATA:
+ return get_num_wrps();
+ default:
+ pr_warn("unknown slot type: %d\n", type);
+ return 0;
+ }
+}
+
+#define READ_WB_REG_CASE(OFF, N, REG, T, VAL) \
+ case (OFF + N): \
+ LOONGARCH_CSR_WATCH_READ(N, REG, T, VAL); \
+ break
+
+#define WRITE_WB_REG_CASE(OFF, N, REG, T, VAL) \
+ case (OFF + N): \
+ LOONGARCH_CSR_WATCH_WRITE(N, REG, T, VAL); \
+ break
+
+#define GEN_READ_WB_REG_CASES(OFF, REG, T, VAL) \
+ READ_WB_REG_CASE(OFF, 0, REG, T, VAL); \
+ READ_WB_REG_CASE(OFF, 1, REG, T, VAL); \
+ READ_WB_REG_CASE(OFF, 2, REG, T, VAL); \
+ READ_WB_REG_CASE(OFF, 3, REG, T, VAL); \
+ READ_WB_REG_CASE(OFF, 4, REG, T, VAL); \
+ READ_WB_REG_CASE(OFF, 5, REG, T, VAL); \
+ READ_WB_REG_CASE(OFF, 6, REG, T, VAL); \
+ READ_WB_REG_CASE(OFF, 7, REG, T, VAL);
+
+#define GEN_WRITE_WB_REG_CASES(OFF, REG, T, VAL) \
+ WRITE_WB_REG_CASE(OFF, 0, REG, T, VAL); \
+ WRITE_WB_REG_CASE(OFF, 1, REG, T, VAL); \
+ WRITE_WB_REG_CASE(OFF, 2, REG, T, VAL); \
+ WRITE_WB_REG_CASE(OFF, 3, REG, T, VAL); \
+ WRITE_WB_REG_CASE(OFF, 4, REG, T, VAL); \
+ WRITE_WB_REG_CASE(OFF, 5, REG, T, VAL); \
+ WRITE_WB_REG_CASE(OFF, 6, REG, T, VAL); \
+ WRITE_WB_REG_CASE(OFF, 7, REG, T, VAL);
+
+static u64 read_wb_reg(int reg, int n, int t)
+{
+ u64 val = 0;
+
+ switch (reg + n) {
+ GEN_READ_WB_REG_CASES(CSR_CFG_ADDR, ADDR, t, val);
+ GEN_READ_WB_REG_CASES(CSR_CFG_MASK, MASK, t, val);
+ GEN_READ_WB_REG_CASES(CSR_CFG_CTRL, CTRL, t, val);
+ GEN_READ_WB_REG_CASES(CSR_CFG_ASID, ASID, t, val);
+ default:
+ pr_warn("Attempt to read from unknown breakpoint register %d\n", n);
+ }
+
+ return val;
+}
+NOKPROBE_SYMBOL(read_wb_reg);
+
+static void write_wb_reg(int reg, int n, int t, u64 val)
+{
+ switch (reg + n) {
+ GEN_WRITE_WB_REG_CASES(CSR_CFG_ADDR, ADDR, t, val);
+ GEN_WRITE_WB_REG_CASES(CSR_CFG_MASK, MASK, t, val);
+ GEN_WRITE_WB_REG_CASES(CSR_CFG_CTRL, CTRL, t, val);
+ GEN_WRITE_WB_REG_CASES(CSR_CFG_ASID, ASID, t, val);
+ default:
+ pr_warn("Attempt to write to unknown breakpoint register %d\n", n);
+ }
+}
+NOKPROBE_SYMBOL(write_wb_reg);
+
+enum hw_breakpoint_ops {
+ HW_BREAKPOINT_INSTALL,
+ HW_BREAKPOINT_UNINSTALL,
+};
+
+/*
+ * hw_breakpoint_slot_setup - Find and setup a perf slot according to operations
+ *
+ * @slots: pointer to array of slots
+ * @max_slots: max number of slots
+ * @bp: perf_event to setup
+ * @ops: operation to be carried out on the slot
+ *
+ * Return:
+ * slot index on success
+ * -ENOSPC if no slot is available/matches
+ * -EINVAL on wrong operations parameter
+ */
+
+static int hw_breakpoint_slot_setup(struct perf_event **slots, int max_slots,
+ struct perf_event *bp, enum hw_breakpoint_ops ops)
+{
+ int i;
+ struct perf_event **slot;
+
+ for (i = 0; i < max_slots; ++i) {
+ slot = &slots[i];
+ switch (ops) {
+ case HW_BREAKPOINT_INSTALL:
+ if (!*slot) {
+ *slot = bp;
+ return i;
+ }
+ break;
+ case HW_BREAKPOINT_UNINSTALL:
+ if (*slot == bp) {
+ *slot = NULL;
+ return i;
+ }
+ break;
+ default:
+ pr_warn_once("Unhandled hw breakpoint ops %d\n", ops);
+ return -EINVAL;
+ }
+ }
+
+ return -ENOSPC;
+}
+
+void ptrace_hw_copy_thread(struct task_struct *tsk)
+{
+ memset(tsk->thread.hbp_break, 0, sizeof(tsk->thread.hbp_break));
+ memset(tsk->thread.hbp_watch, 0, sizeof(tsk->thread.hbp_watch));
+}
+
+/*
+ * Unregister breakpoints from this task and reset the pointers in the thread_struct.
+ */
+void flush_ptrace_hw_breakpoint(struct task_struct *tsk)
+{
+}
+
+static int hw_breakpoint_control(struct perf_event *bp,
+ enum hw_breakpoint_ops ops)
+{
+ u32 ctrl;
+ int i, max_slots, enable;
+ struct perf_event **slots;
+ struct arch_hw_breakpoint *info = counter_arch_bp(bp);
+
+ if (info->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) {
+ /* Breakpoint */
+ slots = this_cpu_ptr(bp_on_reg);
+ max_slots = boot_cpu_data.watch_ireg_count;
+ } else {
+ /* Watchpoint */
+ slots = this_cpu_ptr(wp_on_reg);
+ max_slots = boot_cpu_data.watch_dreg_count;
+ }
+
+ 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:
+ /* Set the FWPnCFG/MWPnCFG 1~4 register. */
+ write_wb_reg(CSR_CFG_ADDR, i, 0, info->address);
+ write_wb_reg(CSR_CFG_ADDR, i, 1, info->address);
+ write_wb_reg(CSR_CFG_MASK, i, 0, info->mask);
+ write_wb_reg(CSR_CFG_MASK, i, 1, info->mask);
+ write_wb_reg(CSR_CFG_ASID, i, 0, 0);
+ write_wb_reg(CSR_CFG_ASID, i, 1, 0);
+ if (info->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) {
+ write_wb_reg(CSR_CFG_CTRL, i, 0, CTRL_PLV_ENABLE);
+ } else {
+ ctrl = encode_ctrl_reg(info->ctrl);
+ write_wb_reg(CSR_CFG_CTRL, i, 1, ctrl | CTRL_PLV_ENABLE |
+ 1 << MWPnCFG3_LoadEn | 1 << MWPnCFG3_StoreEn);
+ }
+ enable = csr_read64(LOONGARCH_CSR_CRMD);
+ csr_write64(CSR_CRMD_WE | enable, LOONGARCH_CSR_CRMD);
+ break;
+ case HW_BREAKPOINT_UNINSTALL:
+ /* Reset the FWPnCFG/MWPnCFG 1~4 register. */
+ write_wb_reg(CSR_CFG_ADDR, i, 0, 0);
+ write_wb_reg(CSR_CFG_ADDR, i, 1, 0);
+ write_wb_reg(CSR_CFG_MASK, i, 0, 0);
+ write_wb_reg(CSR_CFG_MASK, i, 1, 0);
+ write_wb_reg(CSR_CFG_CTRL, i, 0, 0);
+ write_wb_reg(CSR_CFG_CTRL, i, 1, 0);
+ write_wb_reg(CSR_CFG_ASID, i, 0, 0);
+ write_wb_reg(CSR_CFG_ASID, i, 1, 0);
+ break;
+ }
+
+ return 0;
+}
+
+/*
+ * Install a perf counter breakpoint.
+ */
+int arch_install_hw_breakpoint(struct perf_event *bp)
+{
+ return hw_breakpoint_control(bp, HW_BREAKPOINT_INSTALL);
+}
+
+void arch_uninstall_hw_breakpoint(struct perf_event *bp)
+{
+ hw_breakpoint_control(bp, HW_BREAKPOINT_UNINSTALL);
+}
+
+static int get_hbp_len(u8 hbp_len)
+{
+ unsigned int len_in_bytes = 0;
+
+ switch (hbp_len) {
+ case LOONGARCH_BREAKPOINT_LEN_1:
+ len_in_bytes = 1;
+ break;
+ case LOONGARCH_BREAKPOINT_LEN_2:
+ len_in_bytes = 2;
+ break;
+ case LOONGARCH_BREAKPOINT_LEN_4:
+ len_in_bytes = 4;
+ break;
+ case LOONGARCH_BREAKPOINT_LEN_8:
+ len_in_bytes = 8;
+ break;
+ }
+
+ return len_in_bytes;
+}
+
+/*
+ * Check whether bp virtual address is in kernel space.
+ */
+int arch_check_bp_in_kernelspace(struct arch_hw_breakpoint *hw)
+{
+ unsigned int len;
+ unsigned long va;
+
+ va = hw->address;
+ len = get_hbp_len(hw->ctrl.len);
+
+ return (va >= TASK_SIZE) && ((va + len - 1) >= TASK_SIZE);
+}
+
+/*
+ * Extract generic type and length encodings from an arch_hw_breakpoint_ctrl.
+ * Hopefully this will disappear when ptrace can bypass the conversion
+ * to generic breakpoint descriptions.
+ */
+int arch_bp_generic_fields(struct arch_hw_breakpoint_ctrl ctrl,
+ int *gen_len, int *gen_type, int *offset)
+{
+ /* Type */
+ switch (ctrl.type) {
+ case LOONGARCH_BREAKPOINT_EXECUTE:
+ *gen_type = HW_BREAKPOINT_X;
+ break;
+ case LOONGARCH_BREAKPOINT_LOAD:
+ *gen_type = HW_BREAKPOINT_R;
+ break;
+ case LOONGARCH_BREAKPOINT_STORE:
+ *gen_type = HW_BREAKPOINT_W;
+ break;
+ case LOONGARCH_BREAKPOINT_LOAD | LOONGARCH_BREAKPOINT_STORE:
+ *gen_type = HW_BREAKPOINT_RW;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ if (!ctrl.len)
+ return -EINVAL;
+
+ *offset = __ffs(ctrl.len);
+
+ /* Len */
+ switch (ctrl.len) {
+ case LOONGARCH_BREAKPOINT_LEN_1:
+ *gen_len = HW_BREAKPOINT_LEN_1;
+ break;
+ case LOONGARCH_BREAKPOINT_LEN_2:
+ *gen_len = HW_BREAKPOINT_LEN_2;
+ break;
+ case LOONGARCH_BREAKPOINT_LEN_4:
+ *gen_len = HW_BREAKPOINT_LEN_4;
+ break;
+ case LOONGARCH_BREAKPOINT_LEN_8:
+ *gen_len = HW_BREAKPOINT_LEN_8;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/*
+ * Construct an arch_hw_breakpoint from a perf_event.
+ */
+static int arch_build_bp_info(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
+{
+ /* Type */
+ switch (attr->bp_type) {
+ case HW_BREAKPOINT_X:
+ hw->ctrl.type = LOONGARCH_BREAKPOINT_EXECUTE;
+ break;
+ case HW_BREAKPOINT_R:
+ hw->ctrl.type = LOONGARCH_BREAKPOINT_LOAD;
+ break;
+ case HW_BREAKPOINT_W:
+ hw->ctrl.type = LOONGARCH_BREAKPOINT_STORE;
+ break;
+ case HW_BREAKPOINT_RW:
+ hw->ctrl.type = LOONGARCH_BREAKPOINT_LOAD | LOONGARCH_BREAKPOINT_STORE;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Len */
+ switch (attr->bp_len) {
+ case HW_BREAKPOINT_LEN_1:
+ hw->ctrl.len = LOONGARCH_BREAKPOINT_LEN_1;
+ break;
+ case HW_BREAKPOINT_LEN_2:
+ hw->ctrl.len = LOONGARCH_BREAKPOINT_LEN_2;
+ break;
+ case HW_BREAKPOINT_LEN_4:
+ hw->ctrl.len = LOONGARCH_BREAKPOINT_LEN_4;
+ break;
+ case HW_BREAKPOINT_LEN_8:
+ hw->ctrl.len = LOONGARCH_BREAKPOINT_LEN_8;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Address */
+ hw->address = attr->bp_addr;
+
+ return 0;
+}
+
+/*
+ * Validate the arch-specific HW Breakpoint register settings.
+ */
+int hw_breakpoint_arch_parse(struct perf_event *bp,
+ const struct perf_event_attr *attr,
+ struct arch_hw_breakpoint *hw)
+{
+ int ret;
+ u64 alignment_mask, offset;
+
+ /* Build the arch_hw_breakpoint. */
+ ret = arch_build_bp_info(bp, attr, hw);
+ if (ret)
+ return ret;
+
+ if (hw->ctrl.type != LOONGARCH_BREAKPOINT_EXECUTE)
+ alignment_mask = 0x7;
+ offset = hw->address & alignment_mask;
+
+ hw->address &= ~alignment_mask;
+ hw->ctrl.len <<= offset;
+
+ return 0;
+}
+
+static void update_bp_registers(struct pt_regs *regs, int enable, int type)
+{
+ u32 ctrl;
+ int i, max_slots;
+ struct perf_event **slots;
+ struct arch_hw_breakpoint *info;
+
+ switch (type) {
+ case 0:
+ slots = this_cpu_ptr(bp_on_reg);
+ max_slots = boot_cpu_data.watch_ireg_count;
+ break;
+ case 1:
+ slots = this_cpu_ptr(wp_on_reg);
+ max_slots = boot_cpu_data.watch_dreg_count;
+ break;
+ default:
+ return;
+ }
+
+ for (i = 0; i < max_slots; ++i) {
+ if (!slots[i])
+ continue;
+
+ info = counter_arch_bp(slots[i]);
+ if (enable) {
+ if ((info->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) && (type == 0)) {
+ write_wb_reg(CSR_CFG_CTRL, i, 0, CTRL_PLV_ENABLE);
+ write_wb_reg(CSR_CFG_CTRL, i, 0, CTRL_PLV_ENABLE);
+ } else {
+ ctrl = read_wb_reg(CSR_CFG_CTRL, i, 1);
+ if (info->ctrl.type == LOONGARCH_BREAKPOINT_LOAD)
+ ctrl |= 0x1 << MWPnCFG3_LoadEn;
+ if (info->ctrl.type == LOONGARCH_BREAKPOINT_STORE)
+ ctrl |= 0x1 << MWPnCFG3_StoreEn;
+ write_wb_reg(CSR_CFG_CTRL, i, 1, ctrl);
+ }
+ regs->csr_prmd |= CSR_PRMD_PWE;
+ } else {
+ if ((info->ctrl.type == LOONGARCH_BREAKPOINT_EXECUTE) && (type == 0)) {
+ write_wb_reg(CSR_CFG_CTRL, i, 0, 0);
+ } else {
+ ctrl = read_wb_reg(CSR_CFG_CTRL, i, 1);
+ if (info->ctrl.type == LOONGARCH_BREAKPOINT_LOAD)
+ ctrl &= ~0x1 << MWPnCFG3_LoadEn;
+ if (info->ctrl.type == LOONGARCH_BREAKPOINT_STORE)
+ ctrl &= ~0x1 << MWPnCFG3_StoreEn;
+ write_wb_reg(CSR_CFG_CTRL, i, 1, ctrl);
+ }
+ regs->csr_prmd &= ~CSR_PRMD_PWE;
+ }
+ }
+}
+NOKPROBE_SYMBOL(update_bp_registers);
+
+/*
+ * Debug exception handlers.
+ */
+void breakpoint_handler(struct pt_regs *regs)
+{
+ int i;
+ struct perf_event *bp, **slots;
+
+ slots = this_cpu_ptr(bp_on_reg);
+
+ for (i = 0; i < boot_cpu_data.watch_ireg_count; ++i) {
+ bp = slots[i];
+ if (bp == NULL)
+ continue;
+ perf_bp_event(bp, regs);
+ }
+ update_bp_registers(regs, 0, 0);
+}
+NOKPROBE_SYMBOL(breakpoint_handler);
+
+void watchpoint_handler(struct pt_regs *regs)
+{
+ int i;
+ struct perf_event *wp, **slots;
+
+ slots = this_cpu_ptr(wp_on_reg);
+
+ for (i = 0; i < boot_cpu_data.watch_dreg_count; ++i) {
+ wp = slots[i];
+ if (wp == NULL)
+ continue;
+ perf_bp_event(wp, regs);
+ }
+ update_bp_registers(regs, 0, 1);
+}
+NOKPROBE_SYMBOL(watchpoint_handler);
+
+static int __init arch_hw_breakpoint_init(void)
+{
+ int cpu;
+
+ boot_cpu_data.watch_ireg_count = get_num_brps();
+ boot_cpu_data.watch_dreg_count = get_num_wrps();
+
+ pr_info("Found %d breakpoint and %d watchpoint registers.\n",
+ boot_cpu_data.watch_ireg_count, boot_cpu_data.watch_dreg_count);
+
+ for (cpu = 1; cpu < NR_CPUS; cpu++) {
+ cpu_data[cpu].watch_ireg_count = boot_cpu_data.watch_ireg_count;
+ cpu_data[cpu].watch_dreg_count = boot_cpu_data.watch_dreg_count;
+ }
+
+ return 0;
+}
+arch_initcall(arch_hw_breakpoint_init);
+
+void hw_breakpoint_thread_switch(struct task_struct *next)
+{
+ struct pt_regs *regs = task_pt_regs(next);
+
+ /* Update breakpoints */
+ update_bp_registers(regs, 1, 0);
+ /* Update watchpoints */
+ update_bp_registers(regs, 1, 1);
+}
+
+void hw_breakpoint_pmu_read(struct perf_event *bp)
+{
+}
+
+/*
+ * Dummy function to register with die_notifier.
+ */
+int hw_breakpoint_exceptions_notify(struct notifier_block *unused,
+ unsigned long val, void *data)
+{
+ return NOTIFY_DONE;
+}
projects / linux.git / commitdiff