coresight: etm4x: Check for Software Lock

mainline inclusion
from mainline-v5.11-rc5
commit 33d5573a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5YCYK
CVE: NA

Reference: https://lore.kernel.org/r/20210110224850.1880240-15-suzuki.poulose@arm.com

--------------------------------------------------------------------------

The Software lock is not implemented for system instructions
based accesses. So, skip the lock register access in such
cases.

Link: https://lore.kernel.org/r/20210110224850.1880240-15-suzuki.poulose@arm.com
Cc: Mike Leach <mike.leach@linaro.org>
Signed-off-by: NSuzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20210201181351.1475223-17-mathieu.poirier@linaro.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwtracing/coresight/coresight-etm4x-core.c

@@ -107,6 +107,21 @@ static void etm4_os_lock(struct etmv4_drvdata *drvdata)
 	isb();
 }
 
+static void etm4_cs_lock(struct etmv4_drvdata *drvdata,
+			 struct csdev_access *csa)
+{
+	/* Software Lock is only accessible via memory mapped interface */
+	if (csa->io_mem)
+		CS_LOCK(csa->base);
+}
+
+static void etm4_cs_unlock(struct etmv4_drvdata *drvdata,
+			   struct csdev_access *csa)
+{
+	if (csa->io_mem)
+		CS_UNLOCK(csa->base);
+}
+
 static bool etm4_arch_supported(u8 arch)
 {
 	/* Mask out the minor version number */
@@ -259,7 +274,8 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 	struct device *etm_dev = &csdev->dev;
 	struct csdev_access *csa = &csdev->access;
 
-	CS_UNLOCK(drvdata->base);
+
+	etm4_cs_unlock(drvdata, csa);
 	etm4_enable_arch_specific(drvdata);
 
 	etm4_os_unlock(drvdata);
@@ -374,7 +390,7 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 	isb();
 
 done:
-	CS_LOCK(drvdata->base);
+	etm4_cs_lock(drvdata, csa);
 
 	dev_dbg(etm_dev, "cpu: %d enable smp call done: %d\n",
 		drvdata->cpu, rc);
@@ -631,7 +647,7 @@ static void etm4_disable_hw(void *info)
 	struct csdev_access *csa = &csdev->access;
 	int i;
 
-	CS_UNLOCK(drvdata->base);
+	etm4_cs_unlock(drvdata, csa);
 	etm4_disable_arch_specific(drvdata);
 
 	if (!drvdata->skip_power_up) {
@@ -673,8 +689,7 @@ static void etm4_disable_hw(void *info)
 	}
 
 	coresight_disclaim_device_unlocked(csdev);
-
-	CS_LOCK(drvdata->base);
+	etm4_cs_lock(drvdata, csa);
 
 	dev_dbg(&drvdata->csdev->dev,
 		"cpu: %d disable smp call done\n", drvdata->cpu);
@@ -778,12 +793,13 @@ static void etm4_init_arch_data(void *info)
 	u32 etmidr4;
 	u32 etmidr5;
 	struct etmv4_drvdata *drvdata = info;
+	struct csdev_access tmp_csa = CSDEV_ACCESS_IOMEM(drvdata->base);
+	struct csdev_access *csa = &tmp_csa;
 	int i;
 
 	/* Make sure all registers are accessible */
 	etm4_os_unlock(drvdata);
-
-	CS_UNLOCK(drvdata->base);
+	etm4_cs_unlock(drvdata, csa);
 
 	/* find all capabilities of the tracing unit */
 	etmidr0 = readl_relaxed(drvdata->base + TRCIDR0);
@@ -943,7 +959,7 @@ static void etm4_init_arch_data(void *info)
 	drvdata->nrseqstate = BMVAL(etmidr5, 25, 27);
 	/* NUMCNTR, bits[30:28] number of counters available for tracing */
 	drvdata->nr_cntr = BMVAL(etmidr5, 28, 30);
-	CS_LOCK(drvdata->base);
+	etm4_cs_lock(drvdata, csa);
 }
 
 /* Set ELx trace filter access in the TRCVICTLR register */
@@ -1324,8 +1340,7 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
 	dsb(sy);
 	isb();
 
-	CS_UNLOCK(drvdata->base);
-
+	etm4_cs_unlock(drvdata, csa);
 	/* Lock the OS lock to disable trace and external debugger access */
 	etm4_os_lock(drvdata);
 
@@ -1438,7 +1453,7 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
 		writel_relaxed((state->trcpdcr & ~TRCPDCR_PU),
 				drvdata->base + TRCPDCR);
 out:
-	CS_LOCK(drvdata->base);
+	etm4_cs_lock(drvdata, csa);
 	return ret;
 }
 
@@ -1446,9 +1461,10 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 {
 	int i;
 	struct etmv4_save_state *state = drvdata->save_state;
+	struct csdev_access tmp_csa = CSDEV_ACCESS_IOMEM(drvdata->base);
+	struct csdev_access *csa = &tmp_csa;
 
-	CS_UNLOCK(drvdata->base);
-
+	etm4_cs_unlock(drvdata, csa);
 	writel_relaxed(state->trcclaimset, drvdata->base + TRCCLAIMSET);
 
 	writel_relaxed(state->trcprgctlr, drvdata->base + TRCPRGCTLR);
@@ -1545,7 +1561,7 @@ static void etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 
 	/* Unlock the OS lock to re-enable trace and external debug access */
 	etm4_os_unlock(drvdata);
-	CS_LOCK(drvdata->base);
+	etm4_cs_lock(drvdata, csa);
 }
 
 static int etm4_cpu_pm_notify(struct notifier_block *nb, unsigned long cmd,