clk: msm: clock-osm: remove ioremaps from panic callback

Calling ioremap() in clk_osm_panic_callback() can result in
BUG() when the kernel is panic-ing. It is not safe to use
ioremap() in atomic context. Map the debug registers at probe
time instead.

CRs-Fixed: 1086427
Change-Id: Ie14be6ee9ffbcb09009d5d05235e20f6ac215fa0
Signed-off-by: Osvaldo Banuelos <osvaldob@codeaurora.org>

drivers/clk/msm/clock-osm.c

@@ -231,6 +231,8 @@ enum clk_osm_trace_packet_id {
 #define MSM8998V2_PWRCL_BOOT_RATE	1555200000
 #define MSM8998V2_PERFCL_BOOT_RATE	1728000000
 
+#define DEBUG_REG_NUM		3
+
 /* ACD registers */
 #define ACD_HW_VERSION		0x0
 #define ACDCR			0x4
@@ -340,6 +342,12 @@ struct osm_entry {
 	long frequency;
 };
 
+const char *clk_panic_reg_names[] = {"WDOG_DOMAIN_PSTATE_STATUS",
+				     "WDOG_PROGRAM_COUNTER",
+				     "APM_STATUS"};
+const int clk_panic_reg_offsets[] = {WDOG_DOMAIN_PSTATE_STATUS,
+				     WDOG_PROGRAM_COUNTER};
+
 static struct dentry *osm_debugfs_base;
 
 struct clk_osm {
@@ -350,6 +358,7 @@ struct clk_osm {
 	struct platform_device *vdd_dev;
 	void *vbases[NUM_BASES];
 	unsigned long pbases[NUM_BASES];
+	void __iomem *debug_regs[DEBUG_REG_NUM];
 	spinlock_t lock;
 
 	u32 cpu_reg_mask;
@@ -1371,6 +1380,64 @@ static int clk_osm_resources_init(struct platform_device *pdev)
 		perfcl_clk.acd_init = false;
 	}
 
+	pwrcl_clk.debug_regs[0] = devm_ioremap(&pdev->dev,
+					       pwrcl_clk.pbases[OSM_BASE] +
+					       clk_panic_reg_offsets[0],
+					       0x4);
+	if (!pwrcl_clk.debug_regs[0]) {
+		dev_err(&pdev->dev, "Failed to map %s debug register\n",
+			clk_panic_reg_names[0]);
+		return -ENOMEM;
+	}
+
+	pwrcl_clk.debug_regs[1] = devm_ioremap(&pdev->dev,
+					       pwrcl_clk.pbases[OSM_BASE] +
+					       clk_panic_reg_offsets[1],
+					       0x4);
+	if (!pwrcl_clk.debug_regs[1]) {
+		dev_err(&pdev->dev, "Failed to map %s debug register\n",
+			clk_panic_reg_names[1]);
+		return -ENOMEM;
+	}
+
+	pwrcl_clk.debug_regs[2] = devm_ioremap(&pdev->dev,
+					       pwrcl_clk.apm_ctrl_status,
+					       0x4);
+	if (!pwrcl_clk.debug_regs[2]) {
+		dev_err(&pdev->dev, "Failed to map %s debug register\n",
+			clk_panic_reg_names[2]);
+		return -ENOMEM;
+	}
+
+	perfcl_clk.debug_regs[0] = devm_ioremap(&pdev->dev,
+						perfcl_clk.pbases[OSM_BASE] +
+						clk_panic_reg_offsets[0],
+						0x4);
+	if (!perfcl_clk.debug_regs[0]) {
+		dev_err(&pdev->dev, "Failed to map %s debug register\n",
+			clk_panic_reg_names[0]);
+		return -ENOMEM;
+	}
+
+	perfcl_clk.debug_regs[1] = devm_ioremap(&pdev->dev,
+						perfcl_clk.pbases[OSM_BASE] +
+						clk_panic_reg_offsets[1],
+						0x4);
+	if (!perfcl_clk.debug_regs[1]) {
+		dev_err(&pdev->dev, "Failed to map %s debug register\n",
+			clk_panic_reg_names[1]);
+		return -ENOMEM;
+	}
+
+	perfcl_clk.debug_regs[2] = devm_ioremap(&pdev->dev,
+						perfcl_clk.apm_ctrl_status,
+						0x4);
+	if (!perfcl_clk.debug_regs[2]) {
+		dev_err(&pdev->dev, "Failed to map %s debug register\n",
+			clk_panic_reg_names[2]);
+		return -ENOMEM;
+	}
+
 	vdd_pwrcl = devm_regulator_get(&pdev->dev, "vdd-pwrcl");
 	if (IS_ERR(vdd_pwrcl)) {
 		rc = PTR_ERR(vdd_pwrcl);
@@ -2976,36 +3043,16 @@ static int clk_osm_panic_callback(struct notifier_block *nfb,
 				  unsigned long event,
 				  void *data)
 {
-	void __iomem *virt_addr;
-	u32 value, reg;
+	int i;
+	u32 value;
 	struct clk_osm *c = container_of(nfb,
 					 struct clk_osm,
 					 panic_notifier);
 
-	reg = c->pbases[OSM_BASE] + WDOG_DOMAIN_PSTATE_STATUS;
-	virt_addr = ioremap(reg, 0x4);
-	if (virt_addr != NULL) {
-		value = readl_relaxed(virt_addr);
-		pr_err("DOM%d_PSTATE_STATUS[0x%08x]=0x%08x\n", c->cluster_num,
-		       reg, value);
-		iounmap(virt_addr);
-	}
-
-	reg = c->pbases[OSM_BASE] + WDOG_PROGRAM_COUNTER;
-	virt_addr = ioremap(reg, 0x4);
-	if (virt_addr != NULL) {
-		value = readl_relaxed(virt_addr);
-		pr_err("DOM%d_PROGRAM_COUNTER[0x%08x]=0x%08x\n", c->cluster_num,
-		       reg, value);
-		iounmap(virt_addr);
-	}
-
-	virt_addr = ioremap(c->apm_ctrl_status, 0x4);
-	if (virt_addr != NULL) {
-		value = readl_relaxed(virt_addr);
-		pr_err("APM_CTLER_STATUS_%d[0x%08x]=0x%08x\n", c->cluster_num,
-		       c->apm_ctrl_status, value);
-		iounmap(virt_addr);
+	for (i = 0; i < DEBUG_REG_NUM; i++) {
+		value = readl_relaxed(c->debug_regs[i]);
+		pr_err("%s_%d=0x%08x\n", clk_panic_reg_names[i],
+		       c->cluster_num, value);
 	}
 
 	return NOTIFY_OK;
@@ -3108,6 +3155,12 @@ static int cpu_clock_osm_driver_probe(struct platform_device *pdev)
 		msm8998_v2 = true;
 	}
 
+	rc = clk_osm_parse_dt_configs(pdev);
+	if (rc) {
+		dev_err(&pdev->dev, "Unable to parse device tree configurations\n");
+		return rc;
+	}
+
 	rc = clk_osm_resources_init(pdev);
 	if (rc) {
 		if (rc != -EPROBE_DEFER)
@@ -3116,12 +3169,6 @@ static int cpu_clock_osm_driver_probe(struct platform_device *pdev)
 		return rc;
 	}
 
-	rc = clk_osm_parse_dt_configs(pdev);
-	if (rc) {
-		dev_err(&pdev->dev, "Unable to parse device tree configurations\n");
-		return rc;
-	}
-
 	if ((pwrcl_clk.secure_init || perfcl_clk.secure_init) &&
 	    msm8998_v2) {
 		pr_err("unsupported configuration for msm8998 v2\n");