Blackfin arch: kgdb specific code

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <bryan.wu@analog.com>

2 files changed, 422 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/Makefile b/arch/blackfin/kernel/Makefile
index b7b6de824011..6fac57f6ce06 100644
--- a/arch/blackfin/kernel/Makefile
+++ b/arch/blackfin/kernel/Makefile
@@ -14,3 +14,4 @@ obj-$(CONFIG_BF561)		     += bfin_gpio.o
 obj-$(CONFIG_MODULES)                += module.o
 obj-$(CONFIG_BFIN_DMA_5XX)           += bfin_dma_5xx.o
 obj-$(CONFIG_DUAL_CORE_TEST_MODULE)  += dualcore_test.o
+obj-$(CONFIG_KGDB)                   += kgdb.o
diff --git a/arch/blackfin/kernel/kgdb.c b/arch/blackfin/kernel/kgdb.c
new file mode 100644
index 000000000000..a9c15515bfd7
--- /dev/null
+++ b/arch/blackfin/kernel/kgdb.c
@@ -0,0 +1,421 @@
+/*
+ * File:         arch/blackfin/kernel/kgdb.c
+ * Based on:
+ * Author:       Sonic Zhang
+ *
+ * Created:
+ * Description:
+ *
+ * Rev:          $Id: kgdb_bfin_linux-2.6.x.patch 4934 2007-02-13 09:32:11Z sonicz $
+ *
+ * Modified:
+ *               Copyright 2005-2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/ptrace.h>		/* for linux pt_regs struct */
+#include <linux/kgdb.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/debugger.h>
+#include <linux/errno.h>
+#include <linux/irq.h>
+#include <asm/system.h>
+#include <asm/traps.h>
+#include <asm/blackfin.h>
+
+/* Put the error code here just in case the user cares.  */
+int gdb_bf533errcode;
+/* Likewise, the vector number here (since GDB only gets the signal
+   number through the usual means, and that's not very specific).  */
+int gdb_bf533vector = -1;
+
+#if KGDB_MAX_NO_CPUS != 8
+#error change the definition of slavecpulocks
+#endif
+
+void regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+	gdb_regs[BFIN_R0] = regs->r0;
+	gdb_regs[BFIN_R1] = regs->r1;
+	gdb_regs[BFIN_R2] = regs->r2;
+	gdb_regs[BFIN_R3] = regs->r3;
+	gdb_regs[BFIN_R4] = regs->r4;
+	gdb_regs[BFIN_R5] = regs->r5;
+	gdb_regs[BFIN_R6] = regs->r6;
+	gdb_regs[BFIN_R7] = regs->r7;
+	gdb_regs[BFIN_P0] = regs->p0;
+	gdb_regs[BFIN_P1] = regs->p1;
+	gdb_regs[BFIN_P2] = regs->p2;
+	gdb_regs[BFIN_P3] = regs->p3;
+	gdb_regs[BFIN_P4] = regs->p4;
+	gdb_regs[BFIN_P5] = regs->p5;
+	gdb_regs[BFIN_SP] = regs->reserved;
+	gdb_regs[BFIN_FP] = regs->fp;
+	gdb_regs[BFIN_I0] = regs->i0;
+	gdb_regs[BFIN_I1] = regs->i1;
+	gdb_regs[BFIN_I2] = regs->i2;
+	gdb_regs[BFIN_I3] = regs->i3;
+	gdb_regs[BFIN_M0] = regs->m0;
+	gdb_regs[BFIN_M1] = regs->m1;
+	gdb_regs[BFIN_M2] = regs->m2;
+	gdb_regs[BFIN_M3] = regs->m3;
+	gdb_regs[BFIN_B0] = regs->b0;
+	gdb_regs[BFIN_B1] = regs->b1;
+	gdb_regs[BFIN_B2] = regs->b2;
+	gdb_regs[BFIN_B3] = regs->b3;
+	gdb_regs[BFIN_L0] = regs->l0;
+	gdb_regs[BFIN_L1] = regs->l1;
+	gdb_regs[BFIN_L2] = regs->l2;
+	gdb_regs[BFIN_L3] = regs->l3;
+	gdb_regs[BFIN_A0_DOT_X] = regs->a0x;
+	gdb_regs[BFIN_A0_DOT_W] = regs->a0w;
+	gdb_regs[BFIN_A1_DOT_X] = regs->a1x;
+	gdb_regs[BFIN_A1_DOT_W] = regs->a1w;
+	gdb_regs[BFIN_ASTAT] = regs->astat;
+	gdb_regs[BFIN_RETS] = regs->rets;
+	gdb_regs[BFIN_LC0] = regs->lc0;
+	gdb_regs[BFIN_LT0] = regs->lt0;
+	gdb_regs[BFIN_LB0] = regs->lb0;
+	gdb_regs[BFIN_LC1] = regs->lc1;
+	gdb_regs[BFIN_LT1] = regs->lt1;
+	gdb_regs[BFIN_LB1] = regs->lb1;
+	gdb_regs[BFIN_CYCLES] = 0;
+	gdb_regs[BFIN_CYCLES2] = 0;
+	gdb_regs[BFIN_USP] = regs->usp;
+	gdb_regs[BFIN_SEQSTAT] = regs->seqstat;
+	gdb_regs[BFIN_SYSCFG] = regs->syscfg;
+	gdb_regs[BFIN_RETI] = regs->pc;
+	gdb_regs[BFIN_RETX] = regs->retx;
+	gdb_regs[BFIN_RETN] = regs->retn;
+	gdb_regs[BFIN_RETE] = regs->rete;
+	gdb_regs[BFIN_PC] = regs->pc;
+	gdb_regs[BFIN_CC] = 0;
+	gdb_regs[BFIN_EXTRA1] = 0;
+	gdb_regs[BFIN_EXTRA2] = 0;
+	gdb_regs[BFIN_EXTRA3] = 0;
+	gdb_regs[BFIN_IPEND] = regs->ipend;
+}
+
+/*
+ * Extracts ebp, esp and eip values understandable by gdb from the values
+ * saved by switch_to.
+ * thread.esp points to ebp. flags and ebp are pushed in switch_to hence esp
+ * prior to entering switch_to is 8 greater then the value that is saved.
+ * If switch_to changes, change following code appropriately.
+ */
+void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
+{
+	gdb_regs[BFIN_SP] = p->thread.ksp;
+	gdb_regs[BFIN_PC] = p->thread.pc;
+	gdb_regs[BFIN_SEQSTAT] = p->thread.seqstat;
+}
+
+void gdb_regs_to_regs(unsigned long *gdb_regs, struct pt_regs *regs)
+{
+	regs->r0 = gdb_regs[BFIN_R0];
+	regs->r1 = gdb_regs[BFIN_R1];
+	regs->r2 = gdb_regs[BFIN_R2];
+	regs->r3 = gdb_regs[BFIN_R3];
+	regs->r4 = gdb_regs[BFIN_R4];
+	regs->r5 = gdb_regs[BFIN_R5];
+	regs->r6 = gdb_regs[BFIN_R6];
+	regs->r7 = gdb_regs[BFIN_R7];
+	regs->p0 = gdb_regs[BFIN_P0];
+	regs->p1 = gdb_regs[BFIN_P1];
+	regs->p2 = gdb_regs[BFIN_P2];
+	regs->p3 = gdb_regs[BFIN_P3];
+	regs->p4 = gdb_regs[BFIN_P4];
+	regs->p5 = gdb_regs[BFIN_P5];
+	regs->fp = gdb_regs[BFIN_FP];
+	regs->i0 = gdb_regs[BFIN_I0];
+	regs->i1 = gdb_regs[BFIN_I1];
+	regs->i2 = gdb_regs[BFIN_I2];
+	regs->i3 = gdb_regs[BFIN_I3];
+	regs->m0 = gdb_regs[BFIN_M0];
+	regs->m1 = gdb_regs[BFIN_M1];
+	regs->m2 = gdb_regs[BFIN_M2];
+	regs->m3 = gdb_regs[BFIN_M3];
+	regs->b0 = gdb_regs[BFIN_B0];
+	regs->b1 = gdb_regs[BFIN_B1];
+	regs->b2 = gdb_regs[BFIN_B2];
+	regs->b3 = gdb_regs[BFIN_B3];
+	regs->l0 = gdb_regs[BFIN_L0];
+	regs->l1 = gdb_regs[BFIN_L1];
+	regs->l2 = gdb_regs[BFIN_L2];
+	regs->l3 = gdb_regs[BFIN_L3];
+	regs->a0x = gdb_regs[BFIN_A0_DOT_X];
+	regs->a0w = gdb_regs[BFIN_A0_DOT_W];
+	regs->a1x = gdb_regs[BFIN_A1_DOT_X];
+	regs->a1w = gdb_regs[BFIN_A1_DOT_W];
+	regs->rets = gdb_regs[BFIN_RETS];
+	regs->lc0 = gdb_regs[BFIN_LC0];
+	regs->lt0 = gdb_regs[BFIN_LT0];
+	regs->lb0 = gdb_regs[BFIN_LB0];
+	regs->lc1 = gdb_regs[BFIN_LC1];
+	regs->lt1 = gdb_regs[BFIN_LT1];
+	regs->lb1 = gdb_regs[BFIN_LB1];
+	regs->usp = gdb_regs[BFIN_USP];
+	regs->syscfg = gdb_regs[BFIN_SYSCFG];
+	regs->retx = gdb_regs[BFIN_PC];
+	regs->retn = gdb_regs[BFIN_RETN];
+	regs->rete = gdb_regs[BFIN_RETE];
+	regs->pc = gdb_regs[BFIN_PC];
+
+#if 0				/* can't change these */
+	regs->astat = gdb_regs[BFIN_ASTAT];
+	regs->seqstat = gdb_regs[BFIN_SEQSTAT];
+	regs->ipend = gdb_regs[BFIN_IPEND];
+#endif
+}
+
+struct hw_breakpoint {
+	unsigned int occupied:1;
+	unsigned int skip:1;
+	unsigned int enabled:1;
+	unsigned int type:1;
+	unsigned int dataacc:2;
+	unsigned short count;
+	unsigned int addr;
+} breakinfo[HW_BREAKPOINT_NUM];
+
+int kgdb_arch_init(void)
+{
+	kgdb_remove_all_hw_break();
+	return 0;
+}
+
+int kgdb_set_hw_break(unsigned long addr)
+{
+	int breakno;
+	for (breakno = 0; breakno < HW_BREAKPOINT_NUM; breakno++)
+		if (!breakinfo[breakno].occupied) {
+			breakinfo[breakno].occupied = 1;
+			breakinfo[breakno].enabled = 1;
+			breakinfo[breakno].type = 1;
+			breakinfo[breakno].addr = addr;
+			return 0;
+		}
+
+	return -ENOSPC;
+}
+
+int kgdb_remove_hw_break(unsigned long addr)
+{
+	int breakno;
+	for (breakno = 0; breakno < HW_BREAKPOINT_NUM; breakno++)
+		if (breakinfo[breakno].addr == addr)
+			memset(&(breakinfo[breakno]), 0, sizeof(struct hw_breakpoint));
+
+	return 0;
+}
+
+void kgdb_remove_all_hw_break(void)
+{
+	memset(breakinfo, 0, sizeof(struct hw_breakpoint)*8);
+}
+
+/*
+void kgdb_show_info(void)
+{
+	printk(KERN_DEBUG "hwd: wpia0=0x%x, wpiacnt0=%d, wpiactl=0x%x, wpstat=0x%x\n",
+		bfin_read_WPIA0(), bfin_read_WPIACNT0(),
+		bfin_read_WPIACTL(), bfin_read_WPSTAT());
+}
+*/
+
+void kgdb_correct_hw_break(void)
+{
+	int breakno;
+	int correctit;
+	uint32_t wpdactl = bfin_read_WPDACTL();
+
+	correctit = 0;
+	for (breakno = 0; breakno < HW_BREAKPOINT_NUM; breakno++) {
+		if (breakinfo[breakno].type == 1) {
+			switch (breakno) {
+			case 0:
+				if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN0)) {
+					correctit = 1;
+					wpdactl &= ~(WPIREN01|EMUSW0);
+					wpdactl |= WPIAEN0|WPICNTEN0;
+					bfin_write_WPIA0(breakinfo[breakno].addr);
+					bfin_write_WPIACNT0(breakinfo[breakno].skip);
+				} else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN0)) {
+					correctit = 1;
+					wpdactl &= ~WPIAEN0;
+				}
+				break;
+
+			case 1:
+				if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN1)) {
+					correctit = 1;
+					wpdactl &= ~(WPIREN01|EMUSW1);
+					wpdactl |= WPIAEN1|WPICNTEN1;
+					bfin_write_WPIA1(breakinfo[breakno].addr);
+					bfin_write_WPIACNT1(breakinfo[breakno].skip);
+				} else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN1)) {
+					correctit = 1;
+					wpdactl &= ~WPIAEN1;
+				}
+				break;
+
+			case 2:
+				if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN2)) {
+					correctit = 1;
+					wpdactl &= ~(WPIREN23|EMUSW2);
+					wpdactl |= WPIAEN2|WPICNTEN2;
+					bfin_write_WPIA2(breakinfo[breakno].addr);
+					bfin_write_WPIACNT2(breakinfo[breakno].skip);
+				} else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN2)) {
+					correctit = 1;
+					wpdactl &= ~WPIAEN2;
+				}
+				break;
+
+			case 3:
+				if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN3)) {
+					correctit = 1;
+					wpdactl &= ~(WPIREN23|EMUSW3);
+					wpdactl |= WPIAEN3|WPICNTEN3;
+					bfin_write_WPIA3(breakinfo[breakno].addr);
+					bfin_write_WPIACNT3(breakinfo[breakno].skip);
+				} else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN3)) {
+					correctit = 1;
+					wpdactl &= ~WPIAEN3;
+				}
+				break;
+			case 4:
+				if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN4)) {
+					correctit = 1;
+					wpdactl &= ~(WPIREN45|EMUSW4);
+					wpdactl |= WPIAEN4|WPICNTEN4;
+					bfin_write_WPIA4(breakinfo[breakno].addr);
+					bfin_write_WPIACNT4(breakinfo[breakno].skip);
+				} else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN4)) {
+					correctit = 1;
+					wpdactl &= ~WPIAEN4;
+				}
+				break;
+			case 5:
+				if (breakinfo[breakno].enabled && !(wpdactl & WPIAEN5)) {
+					correctit = 1;
+					wpdactl &= ~(WPIREN45|EMUSW5);
+					wpdactl |= WPIAEN5|WPICNTEN5;
+					bfin_write_WPIA5(breakinfo[breakno].addr);
+					bfin_write_WPIACNT5(breakinfo[breakno].skip);
+				} else if (!breakinfo[breakno].enabled && (wpdactl & WPIAEN5)) {
+					correctit = 1;
+					wpdactl &= ~WPIAEN5;
+				}
+				break;
+			}
+		}
+	}
+	if (correctit) {
+		wpdactl &= ~WPAND;
+		wpdactl |= WPPWR;
+		/*printk("correct_hw_break: wpdactl=0x%x\n", wpdactl);*/
+		bfin_write_WPDACTL(wpdactl);
+		CSYNC();
+		/*kgdb_show_info();*/
+	}
+}
+
+void kgdb_disable_hw_debug(struct pt_regs *regs)
+{
+	/* Disable hardware debugging while we are in kgdb */
+	bfin_write_WPIACTL(bfin_read_WPIACTL() & ~0x1);
+	CSYNC();
+}
+
+void kgdb_post_master_code(struct pt_regs *regs, int eVector, int err_code)
+{
+	/* Master processor is completely in the debugger */
+	gdb_bf533vector = eVector;
+	gdb_bf533errcode = err_code;
+}
+
+int kgdb_arch_handle_exception(int exceptionVector, int signo,
+			       int err_code, char *remcom_in_buffer,
+			       char *remcom_out_buffer,
+			       struct pt_regs *linux_regs)
+{
+	long addr;
+	long breakno;
+	char *ptr;
+	int newPC;
+	int wp_status;
+
+	switch (remcom_in_buffer[0]) {
+	case 'c':
+	case 's':
+		if (kgdb_contthread && kgdb_contthread != current) {
+			strcpy(remcom_out_buffer, "E00");
+			break;
+		}
+
+		kgdb_contthread = NULL;
+
+		/* try to read optional parameter, pc unchanged if no parm */
+		ptr = &remcom_in_buffer[1];
+		if (kgdb_hex2long(&ptr, &addr)) {
+			linux_regs->retx = addr;
+		}
+		newPC = linux_regs->retx;
+
+		/* clear the trace bit */
+		linux_regs->syscfg &= 0xfffffffe;
+
+		/* set the trace bit if we're stepping */
+		if (remcom_in_buffer[0] == 's') {
+			linux_regs->syscfg |= 0x1;
+			debugger_step = 1;
+		}
+
+		wp_status = bfin_read_WPSTAT();
+		CSYNC();
+
+		if (exceptionVector == VEC_WATCH) {
+			for (breakno = 0; breakno < 6; ++breakno) {
+				if (wp_status & (1 << breakno)) {
+					breakinfo->skip = 1;
+					break;
+				}
+			}
+		}
+		kgdb_correct_hw_break();
+
+		bfin_write_WPSTAT(0);
+
+		return 0;
+	}			/* switch */
+	return -1;		/* this means that we do not want to exit from the handler */
+}
+
+struct kgdb_arch arch_kgdb_ops = {
+	.gdb_bpt_instr = {0xa1},
+	.flags = KGDB_HW_BREAKPOINT,
+};