misc: mic: Coprocessor State Management (COSM) driver

The COSM driver allows boot, shutdown and reset of Intel MIC devices
via sysfs. This functionality was previously present in the Intel MIC
host driver but has now been taken out into a separate driver so that
it can be shared between multiple generations of Intel MIC products.
The sysfs kernel ABI used by the COSM driver is the same as that
defined originally for the MIC host driver in
Documentation/ABI/testing/sysfs-class-mic.txt.

The COSM driver also contains support for dumping the MIC card log_buf
and doing a "force reset" for the card via debugfs. The OSPM support
present in the MIC host driver has now largely been moved to user
space and only a small required OSPM functionality is now present in
the driver.

Reviewed-by: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Dasaratharaman Chandramouli <dasaratharaman.chandramouli@intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/misc/mic/cosm/cosm_debugfs.c b/drivers/misc/mic/cosm/cosm_debugfs.c
new file mode 100644
index 0000000..30d953d
--- /dev/null
+++ b/drivers/misc/mic/cosm/cosm_debugfs.c
@@ -0,0 +1,155 @@
+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * Copyright(c) 2015 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, 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.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ *
+ * Intel MIC Coprocessor State Management (COSM) Driver
+ *
+ */
+
+#include <linux/debugfs.h>
+#include <linux/slab.h>
+#include "cosm_main.h"
+
+/* Debugfs parent dir */
+static struct dentry *cosm_dbg;
+
+/**
+ * cosm_log_buf_show - Display MIC kernel log buffer
+ *
+ * log_buf addr/len is read from System.map by user space
+ * and populated in sysfs entries.
+ */
+static int cosm_log_buf_show(struct seq_file *s, void *unused)
+{
+	void __iomem *log_buf_va;
+	int __iomem *log_buf_len_va;
+	struct cosm_device *cdev = s->private;
+	void *kva;
+	int size;
+	u64 aper_offset;
+
+	if (!cdev || !cdev->log_buf_addr || !cdev->log_buf_len)
+		goto done;
+
+	mutex_lock(&cdev->cosm_mutex);
+	switch (cdev->state) {
+	case MIC_BOOTING:
+	case MIC_ONLINE:
+	case MIC_SHUTTING_DOWN:
+		break;
+	default:
+		goto unlock;
+	}
+
+	/*
+	 * Card kernel will never be relocated and any kernel text/data mapping
+	 * can be translated to phys address by subtracting __START_KERNEL_map.
+	 */
+	aper_offset = (u64)cdev->log_buf_len - __START_KERNEL_map;
+	log_buf_len_va = cdev->hw_ops->aper(cdev)->va + aper_offset;
+	aper_offset = (u64)cdev->log_buf_addr - __START_KERNEL_map;
+	log_buf_va = cdev->hw_ops->aper(cdev)->va + aper_offset;
+
+	size = ioread32(log_buf_len_va);
+	kva = kmalloc(size, GFP_KERNEL);
+	if (!kva)
+		goto unlock;
+
+	memcpy_fromio(kva, log_buf_va, size);
+	seq_write(s, kva, size);
+	kfree(kva);
+unlock:
+	mutex_unlock(&cdev->cosm_mutex);
+done:
+	return 0;
+}
+
+static int cosm_log_buf_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, cosm_log_buf_show, inode->i_private);
+}
+
+static const struct file_operations log_buf_ops = {
+	.owner   = THIS_MODULE,
+	.open    = cosm_log_buf_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release
+};
+
+/**
+ * cosm_force_reset_show - Force MIC reset
+ *
+ * Invokes the force_reset COSM bus op instead of the standard reset
+ * op in case a force reset of the MIC device is required
+ */
+static int cosm_force_reset_show(struct seq_file *s, void *pos)
+{
+	struct cosm_device *cdev = s->private;
+
+	cosm_stop(cdev, true);
+	return 0;
+}
+
+static int cosm_force_reset_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, cosm_force_reset_show, inode->i_private);
+}
+
+static const struct file_operations force_reset_ops = {
+	.owner   = THIS_MODULE,
+	.open    = cosm_force_reset_debug_open,
+	.read    = seq_read,
+	.llseek  = seq_lseek,
+	.release = single_release
+};
+
+void cosm_create_debug_dir(struct cosm_device *cdev)
+{
+	char name[16];
+
+	if (!cosm_dbg)
+		return;
+
+	scnprintf(name, sizeof(name), "mic%d", cdev->index);
+	cdev->dbg_dir = debugfs_create_dir(name, cosm_dbg);
+	if (!cdev->dbg_dir)
+		return;
+
+	debugfs_create_file("log_buf", 0444, cdev->dbg_dir, cdev, &log_buf_ops);
+	debugfs_create_file("force_reset", 0444, cdev->dbg_dir, cdev,
+			    &force_reset_ops);
+}
+
+void cosm_delete_debug_dir(struct cosm_device *cdev)
+{
+	if (!cdev->dbg_dir)
+		return;
+
+	debugfs_remove_recursive(cdev->dbg_dir);
+}
+
+void cosm_init_debugfs(void)
+{
+	cosm_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
+	if (!cosm_dbg)
+		pr_err("can't create debugfs dir\n");
+}
+
+void cosm_exit_debugfs(void)
+{
+	debugfs_remove(cosm_dbg);
+}