From: Matthias Welwarsky <matthias.welwarsky@sysgo.com>
Date: Fri, 16 Sep 2016 09:34:03 +0000 (+0200)
Subject: aarch64: fix entry into debug state
X-Git-Url: https://git.gag.com/?a=commitdiff_plain;h=d8abda4bd828f40fc76613f4d809d86f4c6f1c97;p=fw%2Fopenocd

aarch64: fix entry into debug state

- armv8 EDSCR has no ITR_EN bit, ITR is always enabled. Writes to this
  bit are ignored but we should not do them anyway
- use dpmv8 function to report the reason for debug entry
- WFAR is a 64bit register

Change-Id: I07b81ecf105ceb7c3ae2f764bb408eb973c1d1de
Signed-off-by: Matthias Welwarsky <matthias.welwarsky@sysgo.com>
---

diff --git a/src/target/aarch64.c b/src/target/aarch64.c
index 8ddc2262f..ef73afd7e 100644
--- a/src/target/aarch64.c
+++ b/src/target/aarch64.c
@@ -1140,49 +1140,45 @@ static int aarch64_resume(struct target *target, int current,
 
 static int aarch64_debug_entry(struct target *target)
 {
-	uint32_t dscr;
 	int retval = ERROR_OK;
 	struct aarch64_common *aarch64 = target_to_aarch64(target);
 	struct armv8_common *armv8 = target_to_armv8(target);
-	uint32_t tmp;
 
 	LOG_DEBUG("dscr = 0x%08" PRIx32, aarch64->cpudbg_dscr);
 
-	/* REVISIT surely we should not re-read DSCR !! */
-	retval = mem_ap_read_atomic_u32(armv8->debug_ap,
-			armv8->debug_base + CPUV8_DBG_DSCR, &dscr);
-	if (retval != ERROR_OK)
-		return retval;
-
 	/* REVISIT see A8 TRM 12.11.4 steps 2..3 -- make sure that any
 	 * imprecise data aborts get discarded by issuing a Data
 	 * Synchronization Barrier:  ARMV4_5_MCR(15, 0, 0, 7, 10, 4).
 	 */
 
-	/* Enable the ITR execution once we are in debug mode */
-	dscr |= DSCR_ITR_EN;
+	/* make sure to clear all sticky errors */
 	retval = mem_ap_write_atomic_u32(armv8->debug_ap,
-			armv8->debug_base + CPUV8_DBG_DSCR, dscr);
+			armv8->debug_base + CPUV8_DBG_DRCR, DRCR_CSE);
 	if (retval != ERROR_OK)
 		return retval;
 
 	/* Examine debug reason */
-	arm_dpm_report_dscr(&armv8->dpm, aarch64->cpudbg_dscr);
-	mem_ap_read_atomic_u32(armv8->debug_ap,
-				   armv8->debug_base + CPUV8_DBG_EDESR, &tmp);
-	if ((tmp & 0x7) == 0x4)
-		target->debug_reason = DBG_REASON_SINGLESTEP;
+	armv8_dpm_report_dscr(&armv8->dpm, aarch64->cpudbg_dscr);
 
 	/* save address of instruction that triggered the watchpoint? */
 	if (target->debug_reason == DBG_REASON_WATCHPOINT) {
-		uint32_t wfar;
+		uint32_t tmp;
+		uint64_t wfar = 0;
 
+		retval = mem_ap_read_atomic_u32(armv8->debug_ap,
+				armv8->debug_base + CPUV8_DBG_WFAR1,
+				&tmp);
+		if (retval != ERROR_OK)
+			return retval;
+		wfar = tmp;
+		wfar = (wfar << 32);
 		retval = mem_ap_read_atomic_u32(armv8->debug_ap,
 				armv8->debug_base + CPUV8_DBG_WFAR0,
-				&wfar);
+				&tmp);
 		if (retval != ERROR_OK)
 			return retval;
-		arm_dpm_report_wfar(&armv8->dpm, wfar);
+		wfar |= tmp;
+		armv8_dpm_report_wfar(&armv8->dpm, wfar);
 	}
 
 	retval = armv8_dpm_read_current_registers(&armv8->dpm);
diff --git a/src/target/arm_dpm.h b/src/target/arm_dpm.h
index ad49b8c44..27badf4de 100644
--- a/src/target/arm_dpm.h
+++ b/src/target/arm_dpm.h
@@ -138,7 +138,7 @@ struct arm_dpm {
 	struct dpm_wp *dwp;
 
 	/** Address of the instruction which triggered a watchpoint. */
-	uint32_t wp_pc;
+	target_addr_t wp_pc;
 
 	/** Recent value of DSCR. */
 	uint32_t dscr;