remoteproc: qcom: Add capability to collect minidumps

This patch adds support for collecting minidump in the event of remoteproc
crash. Parse the minidump table based on remoteproc's unique minidump-id,
read all memory regions from the remoteproc's minidump table entry and
expose the memory to userspace. The remoteproc platform driver can choose
to collect a full/mini dump by specifying the coredump op.

Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Co-developed-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
Co-developed-by: Gurbir Arora <gurbaror@codeaurora.org>
Signed-off-by: Gurbir Arora <gurbaror@codeaurora.org>
Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org>
Link: https://lore.kernel.org/r/1605819935-10726-4-git-send-email-sidgup@codeaurora.org
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

1 files changed, 146 insertions, 0 deletions

diff --git a/drivers/remoteproc/qcom_common.c b/drivers/remoteproc/qcom_common.c
index 085fd73fa23a..4b91e3c9eafa 100644
--- a/drivers/remoteproc/qcom_common.c
+++ b/drivers/remoteproc/qcom_common.c
@@ -17,6 +17,7 @@
 #include <linux/rpmsg/qcom_smd.h>
 #include <linux/slab.h>
 #include <linux/soc/qcom/mdt_loader.h>
+#include <linux/soc/qcom/smem.h>
 
 #include "remoteproc_internal.h"
 #include "qcom_common.h"
@@ -25,6 +26,61 @@
 #define to_smd_subdev(d) container_of(d, struct qcom_rproc_subdev, subdev)
 #define to_ssr_subdev(d) container_of(d, struct qcom_rproc_ssr, subdev)
 
+#define MAX_NUM_OF_SS           10
+#define MAX_REGION_NAME_LENGTH  16
+#define SBL_MINIDUMP_SMEM_ID	602
+#define MD_REGION_VALID		('V' << 24 | 'A' << 16 | 'L' << 8 | 'I' << 0)
+#define MD_SS_ENCR_DONE		('D' << 24 | 'O' << 16 | 'N' << 8 | 'E' << 0)
+#define MD_SS_ENABLED		('E' << 24 | 'N' << 16 | 'B' << 8 | 'L' << 0)
+
+/**
+ * struct minidump_region - Minidump region
+ * @name		: Name of the region to be dumped
+ * @seq_num:		: Use to differentiate regions with same name.
+ * @valid		: This entry to be dumped (if set to 1)
+ * @address		: Physical address of region to be dumped
+ * @size		: Size of the region
+ */
+struct minidump_region {
+	char	name[MAX_REGION_NAME_LENGTH];
+	__le32	seq_num;
+	__le32	valid;
+	__le64	address;
+	__le64	size;
+};
+
+/**
+ * struct minidump_subsystem_toc: Subsystem's SMEM Table of content
+ * @status : Subsystem toc init status
+ * @enabled : if set to 1, this region would be copied during coredump
+ * @encryption_status: Encryption status for this subsystem
+ * @encryption_required : Decides to encrypt the subsystem regions or not
+ * @region_count : Number of regions added in this subsystem toc
+ * @regions_baseptr : regions base pointer of the subsystem
+ */
+struct minidump_subsystem {
+	__le32	status;
+	__le32	enabled;
+	__le32	encryption_status;
+	__le32	encryption_required;
+	__le32	region_count;
+	__le64	regions_baseptr;
+};
+
+/**
+ * struct minidump_global_toc: Global Table of Content
+ * @status : Global Minidump init status
+ * @md_revision : Minidump revision
+ * @enabled : Minidump enable status
+ * @subsystems : Array of subsystems toc
+ */
+struct minidump_global_toc {
+	__le32				status;
+	__le32				md_revision;
+	__le32				enabled;
+	struct minidump_subsystem	subsystems[MAX_NUM_OF_SS];
+};
+
 struct qcom_ssr_subsystem {
 	const char *name;
 	struct srcu_notifier_head notifier_list;
@@ -34,6 +90,96 @@ struct qcom_ssr_subsystem {
 static LIST_HEAD(qcom_ssr_subsystem_list);
 static DEFINE_MUTEX(qcom_ssr_subsys_lock);
 
+static void qcom_minidump_cleanup(struct rproc *rproc)
+{
+	struct rproc_dump_segment *entry, *tmp;
+
+	list_for_each_entry_safe(entry, tmp, &rproc->dump_segments, node) {
+		list_del(&entry->node);
+		kfree(entry->priv);
+		kfree(entry);
+	}
+}
+
+static int qcom_add_minidump_segments(struct rproc *rproc, struct minidump_subsystem *subsystem)
+{
+	struct minidump_region __iomem *ptr;
+	struct minidump_region region;
+	int seg_cnt, i;
+	dma_addr_t da;
+	size_t size;
+	char *name;
+
+	if (WARN_ON(!list_empty(&rproc->dump_segments))) {
+		dev_err(&rproc->dev, "dump segment list already populated\n");
+		return -EUCLEAN;
+	}
+
+	seg_cnt = le32_to_cpu(subsystem->region_count);
+	ptr = ioremap((unsigned long)le64_to_cpu(subsystem->regions_baseptr),
+		      seg_cnt * sizeof(struct minidump_region));
+	if (!ptr)
+		return -EFAULT;
+
+	for (i = 0; i < seg_cnt; i++) {
+		memcpy_fromio(&region, ptr + i, sizeof(region));
+		if (region.valid == MD_REGION_VALID) {
+			name = kstrdup(region.name, GFP_KERNEL);
+			if (!name) {
+				iounmap(ptr);
+				return -ENOMEM;
+			}
+			da = le64_to_cpu(region.address);
+			size = le32_to_cpu(region.size);
+			rproc_coredump_add_custom_segment(rproc, da, size, NULL, name);
+		}
+	}
+
+	iounmap(ptr);
+	return 0;
+}
+
+void qcom_minidump(struct rproc *rproc, unsigned int minidump_id)
+{
+	int ret;
+	struct minidump_subsystem *subsystem;
+	struct minidump_global_toc *toc;
+
+	/* Get Global minidump ToC*/
+	toc = qcom_smem_get(QCOM_SMEM_HOST_ANY, SBL_MINIDUMP_SMEM_ID, NULL);
+
+	/* check if global table pointer exists and init is set */
+	if (IS_ERR(toc) || !toc->status) {
+		dev_err(&rproc->dev, "Minidump TOC not found in SMEM\n");
+		return;
+	}
+
+	/* Get subsystem table of contents using the minidump id */
+	subsystem = &toc->subsystems[minidump_id];
+
+	/**
+	 * Collect minidump if SS ToC is valid and segment table
+	 * is initialized in memory and encryption status is set.
+	 */
+	if (subsystem->regions_baseptr == 0 ||
+	    le32_to_cpu(subsystem->status) != 1 ||
+	    le32_to_cpu(subsystem->enabled) != MD_SS_ENABLED ||
+	    le32_to_cpu(subsystem->encryption_status) != MD_SS_ENCR_DONE) {
+		dev_err(&rproc->dev, "Minidump not ready, skipping\n");
+		return;
+	}
+
+	ret = qcom_add_minidump_segments(rproc, subsystem);
+	if (ret) {
+		dev_err(&rproc->dev, "Failed with error: %d while adding minidump entries\n", ret);
+		goto clean_minidump;
+	}
+	rproc_coredump_using_sections(rproc);
+clean_minidump:
+	qcom_minidump_cleanup(rproc);
+}
+EXPORT_SYMBOL_GPL(qcom_minidump);
+
 static int glink_subdev_start(struct rproc_subdev *subdev)
 {
 	struct qcom_rproc_glink *glink = to_glink_subdev(subdev);