Page MenuHomeFreeBSD
Differential D4037 Diff 9890 sys/arm/arm/debug_monitor.c

Changeset View

Standalone View

View Options

sys/arm/arm/debug_monitor.c

  • This file was added.
/*
* Copyright (c) 2015 Juniper Networks Inc.
* All rights reserved.
*
* Developed by Semihalf.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/types.h>
#include <sys/kdb.h>
#include <sys/pcpu.h>
#include <sys/systm.h>
#include <machine/armreg.h>
#include <machine/cpu.h>
#include <machine/debug_monitor.h>
#include <machine/kdb.h>
#include <machine/param.h>
#include <machine/pcb.h>
#include <ddb/ddb.h>
#include <ddb/db_access.h>
#include <ddb/db_sym.h>
enum dbg_t {
DBG_TYPE_BREAKPOINT = 0,
DBG_TYPE_WATCHPOINT = 1,
};
struct dbg_wb_conf {
enum dbg_t type;
enum dbg_access_t access;
db_addr_t address;
db_expr_t size;
u_int slot;
};
static int dbg_reset_state(void);
static int dbg_setup_breakpoint(db_expr_t, db_expr_t, u_int);
static int dbg_remove_breakpoint(u_int);
static int dbg_find_slot(enum dbg_t, db_expr_t);
static boolean_t dbg_check_slot_free(enum dbg_t, u_int);
static int dbg_remove_xpoint(struct dbg_wb_conf *);
static int dbg_setup_xpoint(struct dbg_wb_conf *);
static boolean_t dbg_capable; /* Indicates that machine is capable of using
HW watchpoints/breakpoints */
static boolean_t dbg_ready[MAXCPU]; /* Debug arch. reset performed on this CPU */
static uint32_t dbg_model; /* Debug Arch. Model */
static boolean_t dbg_ossr; /* OS Save and Restore implemented */
static uint32_t dbg_watchpoint_num;
static uint32_t dbg_breakpoint_num;
static int dbg_ref_count_mme[MAXCPU]; /* Times monitor mode was enabled */
/* ID_DFR0 - Debug Feature Register 0 */
#define ID_DFR0_CP_DEBUG_M_SHIFT 0
#define ID_DFR0_CP_DEBUG_M_MASK (0xF << ID_DFR0_CP_DEBUG_M_SHIFT)
#define ID_DFR0_CP_DEBUG_M_NS (0x0) /* Not supported */
#define ID_DFR0_CP_DEBUG_M_V6 (0x2) /* v6 Debug arch. CP14 access */
#define ID_DFR0_CP_DEBUG_M_V6_1 (0x3) /* v6.1 Debug arch. CP14 access */
#define ID_DFR0_CP_DEBUG_M_V7 (0x4) /* v7 Debug arch. CP14 access */
#define ID_DFR0_CP_DEBUG_M_V7_1 (0x5) /* v7.1 Debug arch. CP14 access */
/* DBGDIDR - Debug ID Register */
#define DBGDIDR_WRPS_SHIFT 28
#define DBGDIDR_WRPS_MASK (0xF << DBGDIDR_WRPS_SHIFT)
#define DBGDIDR_WRPS_NUM(reg) \
((((reg) & DBGDIDR_WRPS_MASK) >> DBGDIDR_WRPS_SHIFT) + 1)
#define DBGDIDR_BRPS_SHIFT 24
#define DBGDIDR_BRPS_MASK (0xF << DBGDIDR_BRPS_SHIFT)
#define DBGDIDR_BRPS_NUM(reg) \
((((reg) & DBGDIDR_BRPS_MASK) >> DBGDIDR_BRPS_SHIFT) + 1)
/* DBGPRSR - Device Powerdown and Reset Status Register */
#define DBGPRSR_PU (1 << 0) /* Powerup status */
/* DBGOSLSR - OS Lock Status Register */
#define DBGOSLSR_OSLM0 (1 << 0)
/* DBGOSDLR - OS Double Lock Register */
#define DBGPRSR_DLK (1 << 0) /* OS Double Lock set */
/* DBGDSCR - Debug Status and Control Register */
#define DBGSCR_MDBG_EN (1 << 15) /* Monitor debug-mode enable */
/* DBGWVR - Watchpoint Value Register */
#define DBGWVR_ADDR_MASK (~0x3U)
/* Watchpoints/breakpoints control register bitfields */
#define DBG_WB_CTRL_LEN_1 (0x1 << 5)
#define DBG_WB_CTRL_LEN_2 (0x3 << 5)
#define DBG_WB_CTRL_LEN_4 (0xf << 5)
#define DBG_WB_CTRL_LEN_8 (0xff << 5)
#define DBG_WB_CTRL_LEN_MASK(x) ((x) & (0xff << 5))
#define DBG_WB_CTRL_EXEC (0x0 << 3)
#define DBG_WB_CTRL_LOAD (0x1 << 3)
#define DBG_WB_CTRL_STORE (0x2 << 3)
#define DBG_WB_CTRL_ACCESS_MASK(x) ((x) & (0x3 << 3))
/* Common for breakpoint and watchpoint */
#define DBG_WB_CTRL_PL1 (0x1 << 1)
#define DBG_WB_CTRL_PL0 (0x2 << 1)
#define DBG_WB_CTRL_PLX_MASK(x) ((x) & (0x3 << 1))
#define DBG_WB_CTRL_E (0x1 << 0)
andrewUnsubmitted
Done
Inline Actions

These and below should be #define<tab>DBG_FOO.

andrew: These and below should be `#define<tab>DBG_FOO`.
/*
* Watchpoint/breakpoint helpers
*/
#define DBG_BKPT_BT_SLOT 0 /* Slot for branch taken */
#define DBG_BKPT_BNT_SLOT 1 /* Slot for branch not taken */
#define OP2_SHIFT 4
/* Opc2 numbers for coprocessor instructions */
#define DBG_WB_BVR 4
#define DBG_WB_BCR 5
#define DBG_WB_WVR 6
#define DBG_WB_WCR 7
#define DBG_REG_BASE_BVR (DBG_WB_BVR << OP2_SHIFT)
#define DBG_REG_BASE_BCR (DBG_WB_BCR << OP2_SHIFT)
#define DBG_REG_BASE_WVR (DBG_WB_WVR << OP2_SHIFT)
#define DBG_REG_BASE_WCR (DBG_WB_WCR << OP2_SHIFT)
#define DBG_WB_READ(cn, cm, op2, val) do { \
__asm __volatile("mrc p14, 0, %0, " #cn "," #cm "," #op2 : "=r" (val)); \
} while (0)
#define DBG_WB_WRITE(cn, cm, op2, val) do { \
__asm __volatile("mcr p14, 0, %0, " #cn "," #cm "," #op2 :: "r" (val)); \
} while (0)
#define READ_WB_REG_CASE(op2, m, val) \
case (((op2) << OP2_SHIFT) + m): \
DBG_WB_READ(c0, c ## m, op2, val); \
break
#define WRITE_WB_REG_CASE(op2, m, val) \
case (((op2) << OP2_SHIFT) + m): \
DBG_WB_WRITE(c0, c ## m, op2, val); \
break
#define SWITCH_CASES_READ_WB_REG(op2, val) \
READ_WB_REG_CASE(op2, 0, val); \
READ_WB_REG_CASE(op2, 1, val); \
READ_WB_REG_CASE(op2, 2, val); \
READ_WB_REG_CASE(op2, 3, val); \
READ_WB_REG_CASE(op2, 4, val); \
READ_WB_REG_CASE(op2, 5, val); \
READ_WB_REG_CASE(op2, 6, val); \
READ_WB_REG_CASE(op2, 7, val); \
READ_WB_REG_CASE(op2, 8, val); \
READ_WB_REG_CASE(op2, 9, val); \
READ_WB_REG_CASE(op2, 10, val); \
READ_WB_REG_CASE(op2, 11, val); \
READ_WB_REG_CASE(op2, 12, val); \
READ_WB_REG_CASE(op2, 13, val); \
READ_WB_REG_CASE(op2, 14, val); \
READ_WB_REG_CASE(op2, 15, val)
#define SWITCH_CASES_WRITE_WB_REG(op2, val) \
WRITE_WB_REG_CASE(op2, 0, val); \
WRITE_WB_REG_CASE(op2, 1, val); \
WRITE_WB_REG_CASE(op2, 2, val); \
WRITE_WB_REG_CASE(op2, 3, val); \
WRITE_WB_REG_CASE(op2, 4, val); \
WRITE_WB_REG_CASE(op2, 5, val); \
WRITE_WB_REG_CASE(op2, 6, val); \
WRITE_WB_REG_CASE(op2, 7, val); \
WRITE_WB_REG_CASE(op2, 8, val); \
WRITE_WB_REG_CASE(op2, 9, val); \
WRITE_WB_REG_CASE(op2, 10, val); \
WRITE_WB_REG_CASE(op2, 11, val); \
WRITE_WB_REG_CASE(op2, 12, val); \
WRITE_WB_REG_CASE(op2, 13, val); \
WRITE_WB_REG_CASE(op2, 14, val); \
WRITE_WB_REG_CASE(op2, 15, val)
static uint32_t
dbg_wb_read_reg(int reg, int n)
{
uint32_t val;
val = 0;
switch (reg + n) {
SWITCH_CASES_READ_WB_REG(DBG_WB_WVR, val);
SWITCH_CASES_READ_WB_REG(DBG_WB_WCR, val);
SWITCH_CASES_READ_WB_REG(DBG_WB_BVR, val);
SWITCH_CASES_READ_WB_REG(DBG_WB_BCR, val);
default:
db_printf(
"trying to read from CP14 reg. using wrong opc2 %d\n",
reg >> OP2_SHIFT);
}
return (val);
}
static void
dbg_wb_write_reg(int reg, int n, uint32_t val)
{
switch (reg + n) {
SWITCH_CASES_WRITE_WB_REG(DBG_WB_WVR, val);
SWITCH_CASES_WRITE_WB_REG(DBG_WB_WCR, val);
SWITCH_CASES_WRITE_WB_REG(DBG_WB_BVR, val);
SWITCH_CASES_WRITE_WB_REG(DBG_WB_BCR, val);
default:
db_printf(
"trying to write to CP14 reg. using wrong opc2 %d\n",
reg >> OP2_SHIFT);
}
isb();
}
boolean_t
kdb_cpu_pc_is_singlestep(db_addr_t pc)
{
if (dbg_find_slot(DBG_TYPE_BREAKPOINT, pc) != ~0U)
return (TRUE);
return (FALSE);
}
void
kdb_cpu_set_singlestep(void)
{
db_expr_t inst;
db_addr_t pc, brpc;
uint32_t wcr;
u_int i;
/*
* Disable watchpoints, e.g. stepping over watched instruction will
* trigger break exception instead of single-step exception and locks
* CPU on that instruction for ever.
*/
for (i = 0; i < dbg_watchpoint_num; i++) {
wcr = dbg_wb_read_reg(DBG_REG_BASE_WCR, i);
if ((wcr & DBG_WB_CTRL_E) != 0) {
dbg_wb_write_reg(DBG_REG_BASE_WCR, i,
(wcr & ~DBG_WB_CTRL_E));
}
}
pc = PC_REGS();
inst = db_get_value(pc, sizeof(pc), FALSE);
if (inst_branch(inst) || inst_call(inst) || inst_return(inst)) {
brpc = branch_taken(inst, pc);
dbg_setup_breakpoint(brpc, INSN_SIZE, DBG_BKPT_BT_SLOT);
}
pc = next_instr_address(pc, 0);
dbg_setup_breakpoint(pc, INSN_SIZE, DBG_BKPT_BNT_SLOT);
}
void
kdb_cpu_clear_singlestep(void)
{
uint32_t wvr, wcr;
u_int i;
dbg_remove_breakpoint(DBG_BKPT_BT_SLOT);
dbg_remove_breakpoint(DBG_BKPT_BNT_SLOT);
/* Restore all watchpoints */
for (i = 0; i < dbg_watchpoint_num; i++) {
wcr = dbg_wb_read_reg(DBG_REG_BASE_WCR, i);
wvr = dbg_wb_read_reg(DBG_REG_BASE_WVR, i);
/* Watchpoint considered not empty if address value is not 0 */
if ((wvr & DBGWVR_ADDR_MASK) != 0) {
dbg_wb_write_reg(DBG_REG_BASE_WCR, i,
(wcr | DBG_WB_CTRL_E));
andrewUnsubmitted
Done
Inline Actions

Why 0x3?

andrew: Why 0x3?
}
}
}
int
dbg_setup_watchpoint(db_expr_t addr, db_expr_t size, enum dbg_access_t access)
{
struct dbg_wb_conf conf;
if (access == HW_BREAKPOINT_X) {
db_printf("Invalid access type for watchpoint: %d\n", access);
return (EINVAL);
}
conf.address = addr;
conf.size = size;
conf.access = access;
conf.type = DBG_TYPE_WATCHPOINT;
return (dbg_setup_xpoint(&conf));
}
int
dbg_remove_watchpoint(db_expr_t addr, db_expr_t size __unused)
{
struct dbg_wb_conf conf;
conf.address = addr;
conf.type = DBG_TYPE_WATCHPOINT;
return (dbg_remove_xpoint(&conf));
}
static int
dbg_setup_breakpoint(db_expr_t addr, db_expr_t size, u_int slot)
{
struct dbg_wb_conf conf;
conf.address = addr;
conf.size = size;
conf.access = HW_BREAKPOINT_X;
conf.type = DBG_TYPE_BREAKPOINT;
conf.slot = slot;
return (dbg_setup_xpoint(&conf));
}
static int
dbg_remove_breakpoint(u_int slot)
{
struct dbg_wb_conf conf;
/* Slot already cleared. Don't recurse */
if (dbg_check_slot_free(DBG_TYPE_BREAKPOINT, slot))
return (0);
conf.slot = slot;
conf.type = DBG_TYPE_BREAKPOINT;
return (dbg_remove_xpoint(&conf));
}
static const char *
dbg_watchtype_str(uint32_t type)
{
switch (type) {
case DBG_WB_CTRL_EXEC:
return ("execute");
case DBG_WB_CTRL_STORE:
return ("write");
case DBG_WB_CTRL_LOAD:
return ("read");
case DBG_WB_CTRL_LOAD | DBG_WB_CTRL_STORE:
return ("read/write");
default:
return ("invalid");
}
}
static int
dbg_watchtype_len(uint32_t len)
{
switch (len) {
case DBG_WB_CTRL_LEN_1:
return (1);
case DBG_WB_CTRL_LEN_2:
return (2);
case DBG_WB_CTRL_LEN_4:
return (4);
case DBG_WB_CTRL_LEN_8:
return (8);
default:
return (0);
}
}
void
dbg_show_watchpoint(void)
{
uint32_t wcr, len, type;
uint32_t addr;
boolean_t is_enabled;
int i;
if (!dbg_capable) {
db_printf("Architecture does not support HW "
"breakpoints/watchpoints\n");
return;
}
db_printf("\nhardware watchpoints:\n");
db_printf(" watch status type len address symbol\n");
db_printf(" ----- -------- ---------- --- ---------- ------------------\n");
for (i = 0; i < dbg_watchpoint_num; i++) {
wcr = dbg_wb_read_reg(DBG_REG_BASE_WCR, i);
if ((wcr & DBG_WB_CTRL_E) != 0)
is_enabled = TRUE;
else
is_enabled = FALSE;
type = DBG_WB_CTRL_ACCESS_MASK(wcr);
len = DBG_WB_CTRL_LEN_MASK(wcr);
addr = dbg_wb_read_reg(DBG_REG_BASE_WVR, i) & DBGWVR_ADDR_MASK;
db_printf(" %-5d %-8s %10s %3d 0x%08x ", i,
is_enabled ? "enabled" : "disabled",
is_enabled ? dbg_watchtype_str(type) : "",
is_enabled ? dbg_watchtype_len(len) : 0,
addr);
db_printsym((db_addr_t)addr, DB_STGY_ANY);
db_printf("\n");
}
}
static boolean_t
dbg_check_slot_free(enum dbg_t type, u_int slot)
{
uint32_t cr, vr;
uint32_t max;
switch(type) {
case DBG_TYPE_BREAKPOINT:
max = dbg_breakpoint_num;
cr = DBG_REG_BASE_BCR;
vr = DBG_REG_BASE_BVR;
break;
case DBG_TYPE_WATCHPOINT:
max = dbg_watchpoint_num;
cr = DBG_REG_BASE_WCR;
vr = DBG_REG_BASE_WVR;
break;
default:
db_printf("%s: Unsupported event type %d\n", __func__, type);
return (FALSE);
}
andrewUnsubmitted
Done
Inline Actions

Why not just make this, and all calls to dprintf, a db_printf?

andrew: Why not just make this, and all calls to dprintf, a db_printf?
if (slot >= max) {
db_printf("%s: Invalid slot number %d, max %d\n",
__func__, slot, max - 1);
return (FALSE);
}
if ((dbg_wb_read_reg(cr, slot) & DBG_WB_CTRL_E) == 0 &&
(dbg_wb_read_reg(vr, slot) & DBGWVR_ADDR_MASK) == 0)
return (TRUE);
return (FALSE);
}
static int
dbg_find_free_slot(enum dbg_t type)
{
u_int max, i;
switch(type) {
case DBG_TYPE_BREAKPOINT:
max = dbg_breakpoint_num;
break;
case DBG_TYPE_WATCHPOINT:
max = dbg_watchpoint_num;
break;
default:
db_printf("Unsupported debug type\n");
return (~0U);
}
andrewUnsubmitted
Done
Inline Actions

Why ~0U? This returns a signed integer.

andrew: Why `~0U`? This returns a signed integer.
for (i = 0; i < max; i++) {
if (dbg_check_slot_free(type, i))
return (i);
}
andrewUnsubmitted
Done
Inline Actions

i is a u_int, but this functions return an int.

andrew: `i` is a u_int, but this functions return an int.
return (~0U);
}
static int
dbg_find_slot(enum dbg_t type, db_expr_t addr)
{
uint32_t reg_addr, reg_ctrl;
u_int max, i;
switch(type) {
case DBG_TYPE_BREAKPOINT:
max = dbg_breakpoint_num;
reg_addr = DBG_REG_BASE_BVR;
reg_ctrl = DBG_REG_BASE_BCR;
break;
case DBG_TYPE_WATCHPOINT:
max = dbg_watchpoint_num;
reg_addr = DBG_REG_BASE_WVR;
reg_ctrl = DBG_REG_BASE_WCR;
break;
default:
db_printf("Unsupported debug type\n");
return (~0U);
}
for (i = 0; i < max; i++) {
if ((dbg_wb_read_reg(reg_addr, i) == addr) &&
((dbg_wb_read_reg(reg_ctrl, i) & DBG_WB_CTRL_E) != 0))
return (i);
}
return (~0U);
}
static __inline boolean_t
dbg_monitor_is_enabled(void)
{
if ((cp14_dbgdscrint_get() & DBGSCR_MDBG_EN) != 0)
return (TRUE);
return (FALSE);
}
andrewUnsubmitted
Done
Inline Actions

return ((cp14_dbgdscrint_get() & DBGSCR_MDBG_EN) != 0);

andrew: `return ((cp14_dbgdscrint_get() & DBGSCR_MDBG_EN) != 0);`
static int
dbg_enable_monitor(void)
{
uint32_t dbg_dscr;
/* Already enabled? Just increment reference counter and return */
if (dbg_monitor_is_enabled()) {
dbg_ref_count_mme[PCPU_GET(cpuid)]++;
return (0);
}
dbg_dscr = cp14_dbgdscrint_get();
switch (dbg_model) {
case ID_DFR0_CP_DEBUG_M_V6:
case ID_DFR0_CP_DEBUG_M_V6_1: /* fall through */
cp14_dbgdscr_v6_set(dbg_dscr | DBGSCR_MDBG_EN);
break;
case ID_DFR0_CP_DEBUG_M_V7: /* fall through */
case ID_DFR0_CP_DEBUG_M_V7_1:
cp14_dbgdscr_v7_set(dbg_dscr | DBGSCR_MDBG_EN);
break;
default:
break;
}
isb();
/* Verify that Monitor mode is set */
if (dbg_monitor_is_enabled()) {
dbg_ref_count_mme[PCPU_GET(cpuid)]++;
return (0);
}
return (ENXIO);
}
static int
dbg_disable_monitor(void)
{
uint32_t dbg_dscr;
if (!dbg_monitor_is_enabled())
return (0);
if (--dbg_ref_count_mme[PCPU_GET(cpuid)] > 0)
return (0);
dbg_dscr = cp14_dbgdscrint_get();
switch (dbg_model) {
case ID_DFR0_CP_DEBUG_M_V6:
case ID_DFR0_CP_DEBUG_M_V6_1: /* fall through */
dbg_dscr &= ~DBGSCR_MDBG_EN;
cp14_dbgdscr_v6_set(dbg_dscr);
break;
case ID_DFR0_CP_DEBUG_M_V7: /* fall through */
andrewUnsubmitted
Done
Inline Actions

Does this not need an isb?

andrew: Does this not need an isb?
case ID_DFR0_CP_DEBUG_M_V7_1:
dbg_dscr &= ~DBGSCR_MDBG_EN;
cp14_dbgdscr_v7_set(dbg_dscr);
break;
default:
return (ENXIO);
}
isb();
return (0);
}
static int
dbg_setup_xpoint(struct dbg_wb_conf *conf)
{
const char *typestr;
uint32_t cr_size, cr_priv, cr_access;
uint32_t reg_ctrl, reg_addr, ctrl, addr;
boolean_t is_bkpt;
u_int cpuid;
u_int i;
int err;
if (!dbg_capable)
return (ENXIO);
is_bkpt = (conf->type == DBG_TYPE_BREAKPOINT);
typestr = is_bkpt ? "breakpoint" : "watchpoint";
cpuid = PCPU_GET(cpuid);
if (!dbg_ready[cpuid]) {
err = dbg_reset_state();
if (err != 0)
return (err);
dbg_ready[cpuid] = TRUE;
}
if (is_bkpt) {
if (dbg_breakpoint_num == 0) {
db_printf("Breakpoints not supported on this architecture\n");
return (ENXIO);
}
i = conf->slot;
if (!dbg_check_slot_free(DBG_TYPE_BREAKPOINT, i)) {
/*
* This should never happen. If it does it means that
* there is an erroneus scenario somewhere. Still, it can
* be done but let's inform the user.
*/
db_printf("ERROR: Breakpoint already set. Replacing...\n");
}
} else {
i = dbg_find_free_slot(DBG_TYPE_WATCHPOINT);
if (i == ~0U) {
db_printf("Can not find slot for %s, max %d slots supported\n",
typestr, dbg_watchpoint_num);
return (ENXIO);
}
}
/* Kernel access only */
cr_priv = DBG_WB_CTRL_PL1;
switch(conf->size) {
case 1:
cr_size = DBG_WB_CTRL_LEN_1;
break;
case 2:
cr_size = DBG_WB_CTRL_LEN_2;
break;
case 4:
cr_size = DBG_WB_CTRL_LEN_4;
break;
case 8:
cr_size = DBG_WB_CTRL_LEN_8;
break;
default:
db_printf("Unsupported address size for %s\n", typestr);
return (EINVAL);
}
if (is_bkpt) {
cr_access = DBG_WB_CTRL_EXEC;
reg_ctrl = DBG_REG_BASE_BCR;
reg_addr = DBG_REG_BASE_BVR;
/* Always unlinked BKPT */
ctrl = (cr_size | cr_access | cr_priv | DBG_WB_CTRL_E);
} else {
switch(conf->access) {
case HW_WATCHPOINT_R:
cr_access = DBG_WB_CTRL_LOAD;
break;
case HW_WATCHPOINT_W:
cr_access = DBG_WB_CTRL_STORE;
break;
case HW_WATCHPOINT_RW:
cr_access = DBG_WB_CTRL_LOAD | DBG_WB_CTRL_STORE;
break;
default:
db_printf("Unsupported exception level for %s\n", typestr);
return (EINVAL);
}
reg_ctrl = DBG_REG_BASE_WCR;
reg_addr = DBG_REG_BASE_WVR;
ctrl = (cr_size | cr_access | cr_priv | DBG_WB_CTRL_E);
}
addr = conf->address;
dbg_wb_write_reg(reg_addr, i, addr);
dbg_wb_write_reg(reg_ctrl, i, ctrl);
return (dbg_enable_monitor());
}
static int
dbg_remove_xpoint(struct dbg_wb_conf *conf)
{
uint32_t reg_ctrl, reg_addr, addr;
u_int cpuid;
u_int i;
int err;
if (!dbg_capable)
return (ENXIO);
cpuid = PCPU_GET(cpuid);
if (!dbg_ready[cpuid]) {
err = dbg_reset_state();
if (err != 0)
return (err);
dbg_ready[cpuid] = TRUE;
}
addr = conf->address;
if (conf->type == DBG_TYPE_BREAKPOINT) {
i = conf->slot;
reg_ctrl = DBG_REG_BASE_BCR;
reg_addr = DBG_REG_BASE_BVR;
} else {
i = dbg_find_slot(DBG_TYPE_WATCHPOINT, addr);
if (i == ~0U) {
db_printf("Can not find watchpoint for address 0%x\n", addr);
return (EINVAL);
}
reg_ctrl = DBG_REG_BASE_WCR;
reg_addr = DBG_REG_BASE_WVR;
}
dbg_wb_write_reg(reg_ctrl, i, 0);
dbg_wb_write_reg(reg_addr, i, 0);
return (dbg_disable_monitor());
}
static __inline uint32_t
dbg_get_debug_model(void)
{
uint32_t dbg_m;
dbg_m = ((cpuinfo.id_dfr0 & ID_DFR0_CP_DEBUG_M_MASK) >>
ID_DFR0_CP_DEBUG_M_SHIFT);
return (dbg_m);
}
static __inline boolean_t
dbg_get_ossr(void)
{
switch (dbg_model) {
case ID_DFR0_CP_DEBUG_M_V6_1:
if ((cp14_dbgoslsr_get() & DBGOSLSR_OSLM0) != 0)
return (TRUE);
return (FALSE);
case ID_DFR0_CP_DEBUG_M_V7_1:
return (TRUE);
default:
return (FALSE);
}
}
static __inline boolean_t
dbg_arch_supported(void)
{
switch (dbg_model) {
case ID_DFR0_CP_DEBUG_M_V6:
case ID_DFR0_CP_DEBUG_M_V6_1:
case ID_DFR0_CP_DEBUG_M_V7:
case ID_DFR0_CP_DEBUG_M_V7_1: /* fall through */
return (TRUE);
default:
/* We only support valid v6.x/v7.x modes through CP14 */
return (FALSE);
}
}
static __inline uint32_t
dbg_get_wrp_num(void)
{
uint32_t dbg_didr;
dbg_didr = cp14_dbgdidr_get();
return (DBGDIDR_WRPS_NUM(dbg_didr));
}
static __inline uint32_t
dgb_get_brp_num(void)
{
uint32_t dbg_didr;
dbg_didr = cp14_dbgdidr_get();
return (DBGDIDR_BRPS_NUM(dbg_didr));
}
static int
dbg_reset_state(void)
{
u_int cpuid;
size_t i;
int err;
cpuid = PCPU_GET(cpuid);
err = 0;
switch (dbg_model) {
case ID_DFR0_CP_DEBUG_M_V6:
/* v6 Debug logic reset upon power-up */
return (0);
case ID_DFR0_CP_DEBUG_M_V6_1:
/* Is core power domain powered up? */
if ((cp14_dbgprsr_get() & DBGPRSR_PU) == 0)
err = ENXIO;
if (err != 0)
break;
if (dbg_ossr)
goto vectr_clr;
break;
case ID_DFR0_CP_DEBUG_M_V7:
break;
case ID_DFR0_CP_DEBUG_M_V7_1:
/* Is double lock set? */
if ((cp14_dbgosdlr_get() & DBGPRSR_DLK) != 0)
err = ENXIO;
break;
default:
break;
}
if (err != 0) {
db_printf("Debug facility locked (CPU%d)\n", cpuid);
return (err);
}
/*
* DBGOSLAR is always implemented for v7.1 Debug Arch. however is
* optional for v7 (depends on OS save and restore support).
*/
if (((dbg_model & ID_DFR0_CP_DEBUG_M_V7_1) != 0) || dbg_ossr) {
/*
* Clear OS lock.
* Writing any other value than 0xC5ACCESS will unlock.
*/
cp14_dbgoslar_set(0);
isb();
}
andrewUnsubmitted
Done
Inline Actions

Can we rely on the isb below for this?

andrew: Can we rely on the isb below for this?
zbbAuthorUnsubmitted
Done
Inline Actions

We need to be sure that OS lock is removed before accessing register below.

zbb: We need to be sure that OS lock is removed before accessing register below.
vectr_clr:
/*
* After reset we must ensure that DBGVCR has a defined value.
* Disable all vector catch events. Safe to use - required in all
* implementations.
*/
cp14_dbgvcr_set(0);
isb();
/*
* We have limited number of {watch,break}points, each consists of
* two registers:
* - wcr/bcr regsiter configurates corresponding {watch,break}point
* behaviour
* - wvr/bvr register keeps address we are hunting for
*
* Reset all breakpoints and watchpoints.
*/
for (i = 0; i < dbg_watchpoint_num; ++i) {
dbg_wb_write_reg(DBG_REG_BASE_WCR, i, 0);
dbg_wb_write_reg(DBG_REG_BASE_WVR, i, 0);
}
for (i = 0; i < dbg_breakpoint_num; ++i) {
dbg_wb_write_reg(DBG_REG_BASE_BCR, i, 0);
dbg_wb_write_reg(DBG_REG_BASE_BVR, i, 0);
}
return (0);
}
void
dbg_monitor_init(void)
{
int err;
/* Fetch ARM Debug Architecture model */
dbg_model = dbg_get_debug_model();
if (!dbg_arch_supported()) {
db_printf("ARM Debug Architecture not supported\n");
return;
}
if (bootverbose) {
db_printf("ARM Debug Architecture %s\n",
(dbg_model == ID_DFR0_CP_DEBUG_M_V6) ? "v6" :
(dbg_model == ID_DFR0_CP_DEBUG_M_V6_1) ? "v6.1" :
(dbg_model == ID_DFR0_CP_DEBUG_M_V7) ? "v7" :
(dbg_model == ID_DFR0_CP_DEBUG_M_V7_1) ? "v7.1" : "unknown");
}
/* Do we have OS Save and Restore mechanism? */
dbg_ossr = dbg_get_ossr();
/* Find out many breakpoints and watchpoints we can use */
dbg_watchpoint_num = dbg_get_wrp_num();
dbg_breakpoint_num = dgb_get_brp_num();
if (bootverbose) {
db_printf("%d watchpoints and %d breakpoints supported\n",
dbg_watchpoint_num, dbg_breakpoint_num);
}
err = dbg_reset_state();
if (err == 0) {
dbg_capable = TRUE;
return;
}
db_printf("HW Breakpoints/Watchpoints not enabled on CPU%d\n",
PCPU_GET(cpuid));
}