soc: qcom: Add snapshot of the cpuss driver

This snapshot is taken as of msm-3.18 commit dacccc6.

CRs-Fixed: 1011333
Change-Id: I4ed06b5602220ed4e30bd37a0633ccb3454f7d43
Signed-off-by: Runmin Wang <runminw@codeaurora.org>

Documentation/devicetree/bindings/cpuss_dump/cpuss_dump.txt

@@ -0,0 +1,27 @@
+CPU Subsystem Dump Driver
+
+The CPU Subsystem dump driver is used to dump various hardware entities
+like the instruction and data tlbs or the unified tlbs etc. to an
+allocated buffer. This allows the data to be analysed in case of corruption.
+
+Required Properties for the cpuss_dump node:
+-compatible = "qcom,cpuss-dump";
+
+All child nodes of cpuss_dump node are interpreted as the various hardware
+entities which need to be dumped.
+
+Required properties of the dump nodes
+
+- qcom,dump-node: phandle to the acutal cpuss hardware entity present
+		  in the cpu map
+- qcom,dump-id: The ID within the data dump table where this entry needs to
+		be added.
+
+Example:
+	msm_cpuss_dump {
+		compatible = "qcom,cpuss-dump";
+		qcom,itlb_dump100 {
+			qcom,dump-node = <&L1_itlb_100>;
+			qcom,dump-id = <34>;
+		};
+	};

drivers/soc/qcom/Kconfig

@@ -460,6 +460,15 @@ config MSM_BOOT_STATS
 	 This figures are reported in mpm sleep clock cycles and have a
 	 resolution of 31 bits as 1 bit is used as an overflow check.
 
+config QCOM_CPUSS_DUMP
+    bool "CPU Subsystem Dumping support"
+    help
+	  Add support to dump various hardware entities such as the instruction
+	  and data tlb's as well as the unified tlb, which are a part of the
+	  cpu subsystem to an allocated buffer. This allows for analysis of the
+	  the entities if corruption is suspected.
+	  If unsure, say N
+
 config MSM_QDSP6_APRV2
         bool "Audio QDSP6 APRv2 support"
         depends on MSM_SMD

drivers/soc/qcom/Makefile

@@ -50,6 +50,7 @@ endif
 
 obj-$(CONFIG_QPNP_HAPTIC) += qpnp-haptic.o
 obj-$(CONFIG_QCOM_GSBI)	+=	qcom_gsbi.o
+obj-$(CONFIG_QCOM_CPUSS_DUMP) += cpuss_dump.o
 obj-$(CONFIG_QCOM_PM)	+=	spm.o
 obj-$(CONFIG_QCOM_SMD) +=	smd.o
 obj-$(CONFIG_QCOM_SMD_RPM)	+= smd-rpm.o

drivers/soc/qcom/cpuss_dump.c

@@ -0,0 +1,125 @@
+/* Copyright (c) 2014-2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <soc/qcom/memory_dump.h>
+
+static int cpuss_dump_probe(struct platform_device *pdev)
+{
+	struct device_node *child_node, *dump_node;
+	const struct device_node *node = pdev->dev.of_node;
+	static dma_addr_t dump_addr;
+	static void *dump_vaddr;
+	struct msm_dump_data *dump_data;
+	struct msm_dump_entry dump_entry;
+	int ret;
+	u32 size, id;
+
+	for_each_available_child_of_node(node, child_node) {
+		dump_node = of_parse_phandle(child_node, "qcom,dump-node", 0);
+
+		if (!dump_node) {
+			dev_err(&pdev->dev, "Unable to find node for %s\n",
+				child_node->name);
+			continue;
+		}
+
+		ret = of_property_read_u32(dump_node, "qcom,dump-size", &size);
+		if (ret) {
+			dev_err(&pdev->dev, "Unable to find size for %s\n",
+					dump_node->name);
+			continue;
+		}
+
+		ret = of_property_read_u32(child_node, "qcom,dump-id", &id);
+		if (ret) {
+			dev_err(&pdev->dev, "Unable to find id for %s\n",
+					child_node->name);
+			continue;
+		}
+
+		dump_vaddr = (void *) dma_alloc_coherent(&pdev->dev, size,
+						&dump_addr, GFP_KERNEL);
+
+		if (!dump_vaddr) {
+			dev_err(&pdev->dev, "Couldn't get memory for dumping\n");
+			continue;
+		}
+
+		memset(dump_vaddr, 0x0, size);
+
+		dump_data = devm_kzalloc(&pdev->dev,
+				sizeof(struct msm_dump_data), GFP_KERNEL);
+		if (!dump_data) {
+			dev_err(&pdev->dev, "Dump data allocation failed\n");
+			dma_free_coherent(&pdev->dev, size, dump_vaddr,
+					dump_addr);
+			continue;
+		}
+
+		dump_data->addr = dump_addr;
+		dump_data->len = size;
+		dump_entry.id = id;
+		dump_entry.addr = virt_to_phys(dump_data);
+		ret = msm_dump_data_register(MSM_DUMP_TABLE_APPS, &dump_entry);
+		if (ret) {
+			dev_err(&pdev->dev, "Data dump setup failed, id = %d\n",
+				id);
+			dma_free_coherent(&pdev->dev, size, dump_vaddr,
+					dump_addr);
+			devm_kfree(&pdev->dev, dump_data);
+		}
+
+	}
+	return 0;
+}
+
+static int cpuss_dump_remove(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static const struct of_device_id cpuss_dump_match_table[] = {
+	{	.compatible = "qcom,cpuss-dump",	},
+	{}
+};
+
+static struct platform_driver cpuss_dump_driver = {
+	.probe = cpuss_dump_probe,
+	.remove = cpuss_dump_remove,
+	.driver = {
+		.name = "msm_cpuss_dump",
+		.owner = THIS_MODULE,
+		.of_match_table = cpuss_dump_match_table,
+	},
+};
+
+static int __init cpuss_dump_init(void)
+{
+	return platform_driver_register(&cpuss_dump_driver);
+}
+
+static void __exit cpuss_dump_exit(void)
+{
+	platform_driver_unregister(&cpuss_dump_driver);
+}
+
+subsys_initcall(cpuss_dump_init);
+module_exit(cpuss_dump_exit)
+