1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c
new file mode 100644
index 000000000..259f65291
--- /dev/null
+++ b/drivers/iommu/omap-iommu-debug.c
@@ -0,0 +1,274 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * omap iommu: debugfs interface
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
+ */
+
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/pm_runtime.h>
+#include <linux/debugfs.h>
+#include <linux/platform_data/iommu-omap.h>
+
+#include "omap-iopgtable.h"
+#include "omap-iommu.h"
+
+static DEFINE_MUTEX(iommu_debug_lock);
+
+static struct dentry *iommu_debug_root;
+
+static inline bool is_omap_iommu_detached(struct omap_iommu *obj)
+{
+	return !obj->domain;
+}
+
+#define pr_reg(name)							\
+	do {								\
+		ssize_t bytes;						\
+		const char *str = "%20s: %08x\n";			\
+		const int maxcol = 32;					\
+		if (len < maxcol)					\
+			goto out;					\
+		bytes = scnprintf(p, maxcol, str, __stringify(name),	\
+				 iommu_read_reg(obj, MMU_##name));	\
+		p += bytes;						\
+		len -= bytes;						\
+	} while (0)
+
+static ssize_t
+omap2_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len)
+{
+	char *p = buf;
+
+	pr_reg(REVISION);
+	pr_reg(IRQSTATUS);
+	pr_reg(IRQENABLE);
+	pr_reg(WALKING_ST);
+	pr_reg(CNTL);
+	pr_reg(FAULT_AD);
+	pr_reg(TTB);
+	pr_reg(LOCK);
+	pr_reg(LD_TLB);
+	pr_reg(CAM);
+	pr_reg(RAM);
+	pr_reg(GFLUSH);
+	pr_reg(FLUSH_ENTRY);
+	pr_reg(READ_CAM);
+	pr_reg(READ_RAM);
+	pr_reg(EMU_FAULT_AD);
+out:
+	return p - buf;
+}
+
+static ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf,
+				   ssize_t bytes)
+{
+	if (!obj || !buf)
+		return -EINVAL;
+
+	pm_runtime_get_sync(obj->dev);
+
+	bytes = omap2_iommu_dump_ctx(obj, buf, bytes);
+
+	pm_runtime_put_sync(obj->dev);
+
+	return bytes;
+}
+
+static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
+			       size_t count, loff_t *ppos)
+{
+	struct omap_iommu *obj = file->private_data;
+	char *p, *buf;
+	ssize_t bytes;
+
+	if (is_omap_iommu_detached(obj))
+		return -EPERM;
+
+	buf = kmalloc(count, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+	p = buf;
+
+	mutex_lock(&iommu_debug_lock);
+
+	bytes = omap_iommu_dump_ctx(obj, p, count);
+	if (bytes < 0)
+		goto err;
+	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
+
+err:
+	mutex_unlock(&iommu_debug_lock);
+	kfree(buf);
+
+	return bytes;
+}
+
+static int
+__dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
+{
+	int i;
+	struct iotlb_lock saved;
+	struct cr_regs tmp;
+	struct cr_regs *p = crs;
+
+	pm_runtime_get_sync(obj->dev);
+	iotlb_lock_get(obj, &saved);
+
+	for_each_iotlb_cr(obj, num, i, tmp) {
+		if (!iotlb_cr_valid(&tmp))
+			continue;
+		*p++ = tmp;
+	}
+
+	iotlb_lock_set(obj, &saved);
+	pm_runtime_put_sync(obj->dev);
+
+	return  p - crs;
+}
+
+static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
+			     struct seq_file *s)
+{
+	seq_printf(s, "%08x %08x %01x\n", cr->cam, cr->ram,
+		   (cr->cam & MMU_CAM_P) ? 1 : 0);
+	return 0;
+}
+
+static size_t omap_dump_tlb_entries(struct omap_iommu *obj, struct seq_file *s)
+{
+	int i, num;
+	struct cr_regs *cr;
+
+	num = obj->nr_tlb_entries;
+
+	cr = kcalloc(num, sizeof(*cr), GFP_KERNEL);
+	if (!cr)
+		return 0;
+
+	num = __dump_tlb_entries(obj, cr, num);
+	for (i = 0; i < num; i++)
+		iotlb_dump_cr(obj, cr + i, s);
+	kfree(cr);
+
+	return 0;
+}
+
+static int tlb_show(struct seq_file *s, void *data)
+{
+	struct omap_iommu *obj = s->private;
+
+	if (is_omap_iommu_detached(obj))
+		return -EPERM;
+
+	mutex_lock(&iommu_debug_lock);
+
+	seq_printf(s, "%8s %8s\n", "cam:", "ram:");
+	seq_puts(s, "-----------------------------------------\n");
+	omap_dump_tlb_entries(obj, s);
+
+	mutex_unlock(&iommu_debug_lock);
+
+	return 0;
+}
+
+static void dump_ioptable(struct seq_file *s)
+{
+	int i, j;
+	u32 da;
+	u32 *iopgd, *iopte;
+	struct omap_iommu *obj = s->private;
+
+	spin_lock(&obj->page_table_lock);
+
+	iopgd = iopgd_offset(obj, 0);
+	for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
+		if (!*iopgd)
+			continue;
+
+		if (!(*iopgd & IOPGD_TABLE)) {
+			da = i << IOPGD_SHIFT;
+			seq_printf(s, "1: 0x%08x 0x%08x\n", da, *iopgd);
+			continue;
+		}
+
+		iopte = iopte_offset(iopgd, 0);
+		for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
+			if (!*iopte)
+				continue;
+
+			da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
+			seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
+		}
+	}
+
+	spin_unlock(&obj->page_table_lock);
+}
+
+static int pagetable_show(struct seq_file *s, void *data)
+{
+	struct omap_iommu *obj = s->private;
+
+	if (is_omap_iommu_detached(obj))
+		return -EPERM;
+
+	mutex_lock(&iommu_debug_lock);
+
+	seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
+	seq_puts(s, "--------------------------\n");
+	dump_ioptable(s);
+
+	mutex_unlock(&iommu_debug_lock);
+
+	return 0;
+}
+
+#define DEBUG_FOPS_RO(name)						\
+	static const struct file_operations name##_fops = {	        \
+		.open = simple_open,					\
+		.read = debug_read_##name,				\
+		.llseek = generic_file_llseek,				\
+	}
+
+DEBUG_FOPS_RO(regs);
+DEFINE_SHOW_ATTRIBUTE(tlb);
+DEFINE_SHOW_ATTRIBUTE(pagetable);
+
+void omap_iommu_debugfs_add(struct omap_iommu *obj)
+{
+	struct dentry *d;
+
+	if (!iommu_debug_root)
+		return;
+
+	d = debugfs_create_dir(obj->name, iommu_debug_root);
+	obj->debug_dir = d;
+
+	debugfs_create_u32("nr_tlb_entries", 0400, d, &obj->nr_tlb_entries);
+	debugfs_create_file("regs", 0400, d, obj, &regs_fops);
+	debugfs_create_file("tlb", 0400, d, obj, &tlb_fops);
+	debugfs_create_file("pagetable", 0400, d, obj, &pagetable_fops);
+}
+
+void omap_iommu_debugfs_remove(struct omap_iommu *obj)
+{
+	if (!obj->debug_dir)
+		return;
+
+	debugfs_remove_recursive(obj->debug_dir);
+}
+
+void __init omap_iommu_debugfs_init(void)
+{
+	iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
+}
+
+void __exit omap_iommu_debugfs_exit(void)
+{
+	debugfs_remove(iommu_debug_root);
+}