Every now and then it's convenient to be able to inspect the content of
SMEM items. Rather than carrying some hack locally let's upstream a
driver that when inserted exposes a debugfs interface for dumping
available items.
Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
---
drivers/soc/qcom/Kconfig | 7 +++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/smem_debugfs.c | 102 ++++++++++++++++++++++++++++++++
3 files changed, 110 insertions(+)
create mode 100644 drivers/soc/qcom/smem_debugfs.c
diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index 3dc3e3d61ea3..7e1dd6b3f33a 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -128,6 +128,13 @@ config QCOM_SMEM
The driver provides an interface to items in a heap shared among all
processors in a Qualcomm platform.
+config QCOM_SMEM_DEBUGFS
+ tristate "Qualcomm Shared Memory Manager (SMEM) DebugFS interface"
+ depends on QCOM_SMEM
+ depends on DEBUG_FS
+ help
+ Provides a debugfs interface for inspecting SMEM.
+
config QCOM_SMD_RPM
tristate "Qualcomm Resource Power Manager (RPM) over SMD"
depends on ARCH_QCOM || COMPILE_TEST
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 93392d9dc7f7..632eefc5a897 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -15,6 +15,7 @@ qcom_rpmh-y += rpmh-rsc.o
qcom_rpmh-y += rpmh.o
obj-$(CONFIG_QCOM_SMD_RPM) += smd-rpm.o
obj-$(CONFIG_QCOM_SMEM) += smem.o
+obj-$(CONFIG_QCOM_SMEM_DEBUGFS) += smem_debugfs.o
obj-$(CONFIG_QCOM_SMEM_STATE) += smem_state.o
obj-$(CONFIG_QCOM_SMP2P) += smp2p.o
obj-$(CONFIG_QCOM_SMSM) += smsm.o
diff --git a/drivers/soc/qcom/smem_debugfs.c b/drivers/soc/qcom/smem_debugfs.c
new file mode 100644
index 000000000000..11ef29a0cada
--- /dev/null
+++ b/drivers/soc/qcom/smem_debugfs.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, Linaro Ltd.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/soc/qcom/smem.h>
+
+struct smem_debugfs {
+ struct dentry *root;
+};
+
+static int smem_debugfs_item_show(struct seq_file *seq, void *p)
+{
+ unsigned long data = (unsigned long)seq->private;
+ unsigned long item = data & 0xffff;
+ unsigned long host = data >> 16;
+ size_t len;
+ void *ptr;
+
+ ptr = qcom_smem_get(host, item, &len);
+ if (IS_ERR(ptr))
+ return PTR_ERR(ptr);
+
+ seq_hex_dump(seq, "", DUMP_PREFIX_OFFSET, 16, 1, ptr, len, true);
+
+ return 0;
+}
+
+static int smem_debugfs_item_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, smem_debugfs_item_show, inode->i_private);
+}
+
+static const struct file_operations smem_debugfs_item_ops = {
+ .open = smem_debugfs_item_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int smem_debugfs_rescan(struct seq_file *seq, void *p)
+{
+ struct dentry *root = seq->private;
+ unsigned long item;
+ unsigned long host;
+ unsigned long data;
+ char name[10];
+ char *ptr;
+
+ for (host = 0; host < 10; host++) {
+ for (item = 0; item < 512; item++) {
+ ptr = qcom_smem_get(host, item, NULL);
+ if (IS_ERR(ptr))
+ continue;
+
+ sprintf(name, "%ld-%ld", host, item);
+
+ data = host << 16 | item;
+ debugfs_create_file(name, 0400, root,
+ (void *)data, &smem_debugfs_item_ops);
+ }
+ }
+
+ return 0;
+}
+
+static int smem_debugfs_rescan_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, smem_debugfs_rescan, inode->i_private);
+}
+
+static const struct file_operations smem_debugfs_rescan_ops = {
+ .open = smem_debugfs_rescan_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static struct dentry *smem_debugfs_root;
+
+static int __init qcom_smem_debugfs_init(void)
+{
+ smem_debugfs_root = debugfs_create_dir("qcom_smem", NULL);
+ debugfs_create_file("rescan", 0400, smem_debugfs_root,
+ smem_debugfs_root, &smem_debugfs_rescan_ops);
+
+ return 0;
+}
+
+static void __exit qcom_smem_debugfs_exit(void)
+{
+ debugfs_remove_recursive(smem_debugfs_root);
+}
+
+module_init(qcom_smem_debugfs_init);
+module_exit(qcom_smem_debugfs_exit);
+
+MODULE_DESCRIPTION("Qualcomm SMEM debugfs driver");
+MODULE_LICENSE("GPL v2");
--
2.29.2
