[PATCH v3 2/8] remoteproc: qcom: Introduce driver to store pil info in IMEM

[Bjorn Andersson]

A region in IMEM is used to communicate load addresses of remoteproc to
post mortem debug tools. Implement a driver that can be used to store
this information in order to enable these tools to process collected
ramdumps.

Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---

Changes since v2:
- Sorted includes
- Replace use of stracpy (still not landed upstream)
- Fixed error handling in probe
- Return error from store, to allow clients to decide action
- Replace hard coded size with value read from reg property

 drivers/remoteproc/Kconfig         |   3 +
 drivers/remoteproc/Makefile        |   1 +
 drivers/remoteproc/qcom_pil_info.c | 168 +++++++++++++++++++++++++++++
 drivers/remoteproc/qcom_pil_info.h |   8 ++
 4 files changed, 180 insertions(+)
 create mode 100644 drivers/remoteproc/qcom_pil_info.c
 create mode 100644 drivers/remoteproc/qcom_pil_info.h

diff --git a/drivers/remoteproc/Kconfig b/drivers/remoteproc/Kconfig
index de3862c15fcc..20c8194e610e 100644
--- a/drivers/remoteproc/Kconfig
+++ b/drivers/remoteproc/Kconfig
@@ -95,6 +95,9 @@ config KEYSTONE_REMOTEPROC
 	  It's safe to say N here if you're not interested in the Keystone
 	  DSPs or just want to use a bare minimum kernel.
 
+config QCOM_PIL_INFO
+	tristate
+
 config QCOM_RPROC_COMMON
 	tristate
 
diff --git a/drivers/remoteproc/Makefile b/drivers/remoteproc/Makefile
index e30a1b15fbac..2ab32bd41b44 100644
--- a/drivers/remoteproc/Makefile
+++ b/drivers/remoteproc/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_OMAP_REMOTEPROC)		+= omap_remoteproc.o
 obj-$(CONFIG_WKUP_M3_RPROC)		+= wkup_m3_rproc.o
 obj-$(CONFIG_DA8XX_REMOTEPROC)		+= da8xx_remoteproc.o
 obj-$(CONFIG_KEYSTONE_REMOTEPROC)	+= keystone_remoteproc.o
+obj-$(CONFIG_QCOM_PIL_INFO)		+= qcom_pil_info.o
 obj-$(CONFIG_QCOM_RPROC_COMMON)		+= qcom_common.o
 obj-$(CONFIG_QCOM_Q6V5_COMMON)		+= qcom_q6v5.o
 obj-$(CONFIG_QCOM_Q6V5_ADSP)		+= qcom_q6v5_adsp.o
diff --git a/drivers/remoteproc/qcom_pil_info.c b/drivers/remoteproc/qcom_pil_info.c
new file mode 100644
index 000000000000..398aeb957f3c
--- /dev/null
+++ b/drivers/remoteproc/qcom_pil_info.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2019-2020 Linaro Ltd.
+ */
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define PIL_RELOC_NAME_LEN	8
+
+struct pil_reloc_entry {
+	char name[PIL_RELOC_NAME_LEN];
+	__le64 base;
+	__le32 size;
+} __packed;
+
+struct pil_reloc {
+	struct device *dev;
+	struct regmap *map;
+	size_t offset;
+	size_t num_entries;
+	int val_bytes;
+
+	struct pil_reloc_entry entries[];
+};
+
+static struct pil_reloc *_reloc;
+static DEFINE_MUTEX(reloc_mutex);
+
+/**
+ * qcom_pil_info_store() - store PIL information of image in IMEM
+ * @image:	name of the image
+ * @base:	base address of the loaded image
+ * @size:	size of the loaded image
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+int qcom_pil_info_store(const char *image, phys_addr_t base, size_t size)
+{
+	struct pil_reloc_entry *entry;
+	int idx = -1;
+	int ret;
+	int i;
+
+	mutex_lock(&reloc_mutex);
+	for (i = 0; i < _reloc->num_entries; i++) {
+		if (!_reloc->entries[i].name[0]) {
+			if (idx == -1)
+				idx = i;
+			continue;
+		}
+
+		if (!strncmp(_reloc->entries[i].name, image, 8)) {
+			idx = i;
+			goto found;
+		}
+	}
+
+	if (idx == -1) {
+		dev_warn(_reloc->dev, "insufficient PIL info slots\n");
+		ret = -ENOMEM;
+		goto unlock;
+	}
+
+found:
+	entry = &_reloc->entries[idx];
+	strscpy(entry->name, image, ARRAY_SIZE(entry->name));
+	entry->base = base;
+	entry->size = size;
+
+	ret = regmap_bulk_write(_reloc->map,
+				_reloc->offset + idx * sizeof(*entry),
+				entry, sizeof(*entry) / _reloc->val_bytes);
+unlock:
+	mutex_unlock(&reloc_mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(qcom_pil_info_store);
+
+/**
+ * qcom_pil_info_available() - query if the pil info is probed
+ *
+ * Return: boolean indicating if the pil info device is probed
+ */
+bool qcom_pil_info_available(void)
+{
+	return !!_reloc;
+}
+EXPORT_SYMBOL_GPL(qcom_pil_info_available);
+
+static int pil_reloc_probe(struct platform_device *pdev)
+{
+	unsigned int num_entries;
+	struct pil_reloc *reloc;
+	struct resource *res;
+	int ret;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -EINVAL;
+
+	num_entries = resource_size(res) / sizeof(struct pil_reloc_entry);
+
+	reloc = devm_kzalloc(&pdev->dev,
+			     struct_size(reloc, entries, num_entries),
+			     GFP_KERNEL);
+	if (!reloc)
+		return -ENOMEM;
+
+	reloc->dev = &pdev->dev;
+	reloc->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
+	if (IS_ERR(reloc->map))
+		return PTR_ERR(reloc->map);
+
+	reloc->offset = res->start;
+	reloc->num_entries = num_entries;
+
+	reloc->val_bytes = regmap_get_val_bytes(reloc->map);
+	if (reloc->val_bytes < 0)
+		return -EINVAL;
+
+	ret = regmap_bulk_write(reloc->map, reloc->offset, reloc->entries,
+				reloc->num_entries *
+				sizeof(struct pil_reloc_entry) /
+				reloc->val_bytes);
+	if (ret < 0)
+		return ret;
+
+	mutex_lock(&reloc_mutex);
+	_reloc = reloc;
+	mutex_unlock(&reloc_mutex);
+
+	return 0;
+}
+
+static int pil_reloc_remove(struct platform_device *pdev)
+{
+	mutex_lock(&reloc_mutex);
+	_reloc = NULL;
+	mutex_unlock(&reloc_mutex);
+
+	return 0;
+}
+
+static const struct of_device_id pil_reloc_of_match[] = {
+	{ .compatible = "qcom,pil-reloc-info" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, pil_reloc_of_match);
+
+static struct platform_driver pil_reloc_driver = {
+	.probe = pil_reloc_probe,
+	.remove = pil_reloc_remove,
+	.driver = {
+		.name = "qcom-pil-reloc-info",
+		.of_match_table = pil_reloc_of_match,
+	},
+};
+module_platform_driver(pil_reloc_driver);
+
+MODULE_DESCRIPTION("Qualcomm PIL relocation info");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/remoteproc/qcom_pil_info.h b/drivers/remoteproc/qcom_pil_info.h
new file mode 100644
index 000000000000..93aaaca8aed2
--- /dev/null
+++ b/drivers/remoteproc/qcom_pil_info.h
@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __QCOM_PIL_INFO_H__
+#define __QCOM_PIL_INFO_H__
+
+int qcom_pil_info_store(const char *image, phys_addr_t base, size_t size);
+bool qcom_pil_info_available(void);
+
+#endif
-- 
2.24.0