[PATCH] drm/amdkfd: add pasid debugfs entries

[Eric Huang]

the entries will be appearing at
/sys/kernel/debug/kfd/proc/<pid>/pasid_<gpuid>.

Signed-off-by: Eric Huang <jinhuieric.huang at amd.com>
---
 drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c | 77 ++++++++++++++++++++++++
 drivers/gpu/drm/amd/amdkfd/kfd_priv.h    |  5 ++
 drivers/gpu/drm/amd/amdkfd/kfd_process.c |  3 +
 3 files changed, 85 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c b/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c
index 4a5a0a4e00f2..14ab770fb877 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_debugfs.c
@@ -27,6 +27,16 @@
 #include "kfd_priv.h"
 
 static struct dentry *debugfs_root;
+static struct dentry *debugfs_proc;
+static struct list_head procs;
+
+struct debugfs_proc_entry {
+	struct list_head list;
+	struct dentry *proc_dentry;
+	pid_t pid;
+};
+
+#define MAX_DEBUGFS_FILENAME_LEN 32
 
 static int kfd_debugfs_open(struct inode *inode, struct file *file)
 {
@@ -92,6 +102,8 @@ static const struct file_operations kfd_debugfs_hang_hws_fops = {
 void kfd_debugfs_init(void)
 {
 	debugfs_root = debugfs_create_dir("kfd", NULL);
+	debugfs_proc = debugfs_create_dir("proc", debugfs_root);
+	INIT_LIST_HEAD(&procs);
 
 	debugfs_create_file("mqds", S_IFREG | 0444, debugfs_root,
 			    kfd_debugfs_mqds_by_process, &kfd_debugfs_fops);
@@ -107,5 +119,70 @@ void kfd_debugfs_init(void)
 
 void kfd_debugfs_fini(void)
 {
+	debugfs_remove_recursive(debugfs_proc);
 	debugfs_remove_recursive(debugfs_root);
 }
+
+static ssize_t kfd_debugfs_pasid_read(struct file *file, char __user *buf,
+				      size_t count, loff_t *ppos)
+{
+    struct kfd_process_device *pdd = file_inode(file)->i_private;
+    char tmp[32];
+    int len;
+
+    len = snprintf(tmp, sizeof(tmp), "%u\n", pdd->pasid);
+
+    return simple_read_from_buffer(buf, count, ppos, tmp, len);
+}
+
+static const struct file_operations kfd_debugfs_pasid_fops = {
+    .owner = THIS_MODULE,
+    .read = kfd_debugfs_pasid_read,
+};
+
+void kfd_debugfs_add_process(struct kfd_process *p)
+{
+	int i;
+	char name[MAX_DEBUGFS_FILENAME_LEN];
+	struct debugfs_proc_entry *entry;
+
+	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+	if (!entry)
+		return;
+
+	list_add(&entry->list, &procs);
+	entry->pid = p->lead_thread->pid;
+	snprintf(name, MAX_DEBUGFS_FILENAME_LEN, "%d",
+		 (int)entry->pid);
+	entry->proc_dentry = debugfs_create_dir(name, debugfs_proc);
+
+	/* Create debugfs files for each GPU:
+	 * - proc/<pid>/pasid_<gpuid>
+	 */
+	for (i = 0; i < p->n_pdds; i++) {
+		struct kfd_process_device *pdd = p->pdds[i];
+
+		snprintf(name, MAX_DEBUGFS_FILENAME_LEN, "pasid_%u",
+			 pdd->dev->id);
+		debugfs_create_file((const char *)name, S_IFREG | 0444,
+				    entry->proc_dentry,
+				    pdd,
+				    &kfd_debugfs_pasid_fops);
+	}
+}
+
+void kfd_debugfs_remove_process(struct kfd_process *p)
+{
+	struct debugfs_proc_entry *entry, *next;
+
+	mutex_lock(&kfd_processes_mutex);
+	list_for_each_entry_safe(entry, next, &procs, list) {
+		if (entry->pid != p->lead_thread->pid)
+			continue;
+
+		debugfs_remove_recursive(entry->proc_dentry);
+		list_del(&entry->list);
+		kfree(entry);
+	}
+	mutex_unlock(&kfd_processes_mutex);
+}
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index f6aedf69c644..0ae794539bb0 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -1581,10 +1581,15 @@ int kfd_debugfs_hang_hws(struct kfd_node *dev);
 int pm_debugfs_hang_hws(struct packet_manager *pm);
 int dqm_debugfs_hang_hws(struct device_queue_manager *dqm);
 
+void kfd_debugfs_add_process(struct kfd_process *p);
+void kfd_debugfs_remove_process(struct kfd_process *p);
+
 #else
 
 static inline void kfd_debugfs_init(void) {}
 static inline void kfd_debugfs_fini(void) {}
+static inline void kfd_debugfs_add_process(struct kfd_process *p) {}
+static inline void kfd_debugfs_remove_process(struct kfd_process *p) {}
 
 #endif
 
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index 41d7dc8c2850..722ac1662bdc 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -900,6 +900,8 @@ struct kfd_process *kfd_create_process(struct task_struct *thread)
 		kfd_procfs_add_sysfs_files(process);
 		kfd_procfs_add_sysfs_counters(process);
 
+		kfd_debugfs_add_process(process);
+
 		init_waitqueue_head(&process->wait_irq_drain);
 	}
 out:
@@ -1176,6 +1178,7 @@ static void kfd_process_wq_release(struct work_struct *work)
 		dma_fence_signal(ef);
 
 	kfd_process_remove_sysfs(p);
+	kfd_debugfs_remove_process(p);
 
 	kfd_process_kunmap_signal_bo(p);
 	kfd_process_free_outstanding_kfd_bos(p);
-- 
2.34.1