[PATCH 02/10] OMAP: iommu: add initial debugfs support

[Tony Lindgren <tony@atomide.com>]

From: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>

This enables to peek the following data.

$ /debug/iommu/isp# ls
mem             nr_tlb_entries  regs
mmap            pagetable       tlb
$ /debug/iommu/isp# head pagetable
L:      da:      pa:
-----------------------------------------
2: 00001000 8ae4a002
2: 00002000 8e7bb002
2: 00003000 8ae49002
2: 00004000 8ae65002
.....

Signed-off-by: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 arch/arm/plat-omap/Kconfig       |    4 
 arch/arm/plat-omap/Makefile      |    1 
 arch/arm/plat-omap/iommu-debug.c |  334 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 339 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/plat-omap/iommu-debug.c

diff --git a/arch/arm/plat-omap/Kconfig b/arch/arm/plat-omap/Kconfig
index efe85d0..ab9f9ef 100644
--- a/arch/arm/plat-omap/Kconfig
+++ b/arch/arm/plat-omap/Kconfig
@@ -120,6 +120,10 @@ config OMAP_MBOX_FWK
 config OMAP_IOMMU
 	tristate
 
+config OMAP_IOMMU_DEBUG
+	depends on OMAP_IOMMU
+	tristate
+
 choice
         prompt "System timer"
 	default OMAP_MPU_TIMER
diff --git a/arch/arm/plat-omap/Makefile b/arch/arm/plat-omap/Makefile
index a832795..769a4c2 100644
--- a/arch/arm/plat-omap/Makefile
+++ b/arch/arm/plat-omap/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_ARCH_OMAP16XX) += ocpi.o
 
 obj-$(CONFIG_OMAP_MCBSP) += mcbsp.o
 obj-$(CONFIG_OMAP_IOMMU) += iommu.o iovmm.o
+obj-$(CONFIG_OMAP_IOMMU_DEBUG) += iommu-debug.o
 
 obj-$(CONFIG_CPU_FREQ) += cpu-omap.o
 obj-$(CONFIG_OMAP_DM_TIMER) += dmtimer.o
diff --git a/arch/arm/plat-omap/iommu-debug.c b/arch/arm/plat-omap/iommu-debug.c
new file mode 100644
index 0000000..9811c19
--- /dev/null
+++ b/arch/arm/plat-omap/iommu-debug.c
@@ -0,0 +1,334 @@
+/*
+ * omap iommu: debugfs interface
+ *
+ * Copyright (C) 2008-2009 Nokia Corporation
+ *
+ * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
+ *
+ * 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.
+ */
+
+#include <linux/err.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <linux/platform_device.h>
+#include <linux/debugfs.h>
+
+#include <mach/iommu.h>
+#include <mach/iovmm.h>
+
+#include "iopgtable.h"
+
+#define MAXCOLUMN 100 /* for short messages */
+
+static DEFINE_MUTEX(iommu_debug_lock);
+static char local_buffer[SZ_4K];
+
+static struct dentry *iommu_debug_root;
+
+static ssize_t debug_read_ver(struct file *file, char __user *userbuf,
+			      size_t count, loff_t *ppos)
+{
+	u32 ver = iommu_arch_version();
+	char buf[MAXCOLUMN], *p = buf;
+
+	p += sprintf(p, "H/W version: %d.%d\n", (ver >> 4) & 0xf , ver & 0xf);
+
+	return simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
+}
+
+static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
+			       size_t count, loff_t *ppos)
+{
+	struct iommu *obj = file->private_data;
+	char *p = local_buffer;
+	ssize_t bytes;
+
+	mutex_lock(&iommu_debug_lock);
+	p += iommu_dump_ctx(obj, p);
+	bytes = simple_read_from_buffer(userbuf, count, ppos, local_buffer,
+					p - local_buffer);
+	mutex_unlock(&iommu_debug_lock);
+	return bytes;
+}
+
+static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
+			      size_t count, loff_t *ppos)
+{
+	struct iommu *obj = file->private_data;
+	char *p = local_buffer;
+	ssize_t bytes;
+
+	mutex_lock(&iommu_debug_lock);
+	p += sprintf(p, "%8s %8s\n", "cam:", "ram:");
+	p += sprintf(p, "-----------------------------------------\n");
+	p += dump_tlb_entries(obj, p);
+	bytes = simple_read_from_buffer(userbuf, count, ppos, local_buffer,
+					p - local_buffer);
+	mutex_unlock(&iommu_debug_lock);
+	return bytes;
+}
+
+static ssize_t debug_write_pagetable(struct file *file,
+		     const char __user *userbuf, size_t count, loff_t *ppos)
+{
+	struct iotlb_entry e;
+	struct cr_regs cr;
+	int err;
+	struct iommu *obj = file->private_data;
+	char buf[MAXCOLUMN], *p = buf;
+
+	count = min(count, sizeof(buf));
+
+	mutex_lock(&iommu_debug_lock);
+	if (copy_from_user(p, userbuf, count)) {
+		mutex_unlock(&iommu_debug_lock);
+		return -EFAULT;
+	}
+
+	sscanf(p, "%x %x", &cr.cam, &cr.ram);
+	if (!cr.cam || !cr.ram) {
+		mutex_unlock(&iommu_debug_lock);
+		return -EINVAL;
+	}
+
+	iotlb_cr_to_e(&cr, &e);
+	err = iopgtable_store_entry(obj, &e);
+	if (err)
+		dev_err(obj->dev, "%s: fail to store cr\n", __func__);
+
+	mutex_unlock(&iommu_debug_lock);
+	return count;
+}
+
+static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
+				    size_t count, loff_t *ppos)
+{
+	int i;
+	u32 *iopgd;
+	struct iommu *obj = file->private_data;
+	char *p = local_buffer;
+	ssize_t bytes;
+
+	mutex_lock(&iommu_debug_lock);
+
+	p += sprintf(p, "L: %8s %8s\n", "da:", "pa:");
+	p += sprintf(p, "-----------------------------------------\n");
+
+	spin_lock(&obj->page_table_lock);
+
+	iopgd = iopgd_offset(obj, 0);
+	for (i = 0; i < PTRS_PER_IOPGD; i++, iopgd++) {
+		int j;
+		u32 *iopte;
+
+		if (!*iopgd)
+			continue;
+
+		if (!(*iopgd & IOPGD_TABLE)) {
+			u32 da;
+
+			da = i << IOPGD_SHIFT;
+			p += sprintf(p, "1: %08x %08x\n", da, *iopgd);
+			continue;
+		}
+
+		iopte = iopte_offset(iopgd, 0);
+
+		for (j = 0; j < PTRS_PER_IOPTE; j++, iopte++) {
+			u32 da;
+
+			if (!*iopte)
+				continue;
+
+			da = (i << IOPGD_SHIFT) + (j << IOPTE_SHIFT);
+			p += sprintf(p, "2: %08x %08x\n", da, *iopte);
+		}
+	}
+	spin_unlock(&obj->page_table_lock);
+
+	bytes = simple_read_from_buffer(userbuf, count, ppos, local_buffer,
+					p - local_buffer);
+	mutex_unlock(&iommu_debug_lock);
+	return bytes;
+}
+
+static ssize_t debug_read_mmap(struct file *file, char __user *userbuf,
+			       size_t count, loff_t *ppos)
+{
+	struct iommu *obj = file->private_data;
+	char *p = local_buffer;
+	struct iovm_struct *tmp;
+	int uninitialized_var(i);
+	ssize_t bytes;
+
+	mutex_lock(&iommu_debug_lock);
+
+	p += sprintf(p, "%-3s %-8s %-8s %6s %8s\n",
+		     "No", "start", "end", "size", "flags");
+	p += sprintf(p, "-------------------------------------------------\n");
+
+	list_for_each_entry(tmp, &obj->mmap, list) {
+		size_t len;
+
+		len = tmp->da_end - tmp->da_start;
+		p += sprintf(p, "%3d %08x-%08x %6x %8x\n",
+			     i, tmp->da_start, tmp->da_end, len, tmp->flags);
+		i++;
+	}
+	bytes = simple_read_from_buffer(userbuf, count, ppos, local_buffer,
+					p - local_buffer);
+	mutex_unlock(&iommu_debug_lock);
+	return bytes;
+}
+
+static ssize_t debug_read_mem(struct file *file, char __user *userbuf,
+			      size_t count, loff_t *ppos)
+{
+	struct iommu *obj = file->private_data;
+	char *p = local_buffer;
+	struct iovm_struct *area;
+	ssize_t bytes;
+
+	mutex_lock(&iommu_debug_lock);
+
+	area = find_iovm_area(obj, (u32)ppos);
+	if (IS_ERR(area)) {
+		mutex_unlock(&iommu_debug_lock);
+		return -EINVAL;
+	}
+	memcpy(p, area->va, count);
+	p += count;
+
+	bytes = simple_read_from_buffer(userbuf, count, ppos, local_buffer,
+					p - local_buffer);
+	mutex_unlock(&iommu_debug_lock);
+	return bytes;
+}
+
+static ssize_t debug_write_mem(struct file *file, const char __user *userbuf,
+			       size_t count, loff_t *ppos)
+{
+	struct iommu *obj = file->private_data;
+	struct iovm_struct *area;
+	char *p = local_buffer;
+
+	count = min(count, sizeof(local_buffer));
+
+	mutex_lock(&iommu_debug_lock);
+
+	if (copy_from_user(p, userbuf, count)) {
+		mutex_unlock(&iommu_debug_lock);
+		return -EFAULT;
+	}
+
+	area = find_iovm_area(obj, (u32)ppos);
+	if (IS_ERR(area)) {
+		mutex_unlock(&iommu_debug_lock);
+		return -EINVAL;
+	}
+	memcpy(area->va, p, count);
+	mutex_unlock(&iommu_debug_lock);
+	return count;
+}
+
+static int debug_open_generic(struct inode *inode, struct file *file)
+{
+	file->private_data = inode->i_private;
+	return 0;
+}
+
+#define DEBUG_FOPS(name)						\
+	static const struct file_operations debug_##name##_fops = {	\
+		.open = debug_open_generic,				\
+		.read = debug_read_##name,				\
+		.write = debug_write_##name,				\
+	};
+
+#define DEBUG_FOPS_RO(name)						\
+	static const struct file_operations debug_##name##_fops = {	\
+		.open = debug_open_generic,				\
+		.read = debug_read_##name,				\
+	};
+
+DEBUG_FOPS_RO(ver);
+DEBUG_FOPS_RO(regs);
+DEBUG_FOPS_RO(tlb);
+DEBUG_FOPS(pagetable);
+DEBUG_FOPS_RO(mmap);
+DEBUG_FOPS(mem);
+
+#define __DEBUG_ADD_FILE(attr, mode)					\
+	{								\
+		struct dentry *dent;					\
+		dent = debugfs_create_file(#attr, mode, parent,		\
+					   obj, &debug_##attr##_fops);	\
+		if (!dent)						\
+			return -ENOMEM;					\
+	}
+
+#define DEBUG_ADD_FILE(name) __DEBUG_ADD_FILE(name, 600)
+#define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 400)
+
+static int iommu_debug_register(struct device *dev, void *data)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct iommu *obj = platform_get_drvdata(pdev);
+	struct dentry *d, *parent;
+
+	if (!obj || !obj->dev)
+		return -EINVAL;
+
+	d = debugfs_create_dir(obj->name, iommu_debug_root);
+	if (!d)
+		return -ENOMEM;
+	parent = d;
+
+	d = debugfs_create_u8("nr_tlb_entries", 400, parent,
+			      (u8 *)&obj->nr_tlb_entries);
+	if (!d)
+		return -ENOMEM;
+
+	DEBUG_ADD_FILE_RO(ver);
+	DEBUG_ADD_FILE_RO(regs);
+	DEBUG_ADD_FILE_RO(tlb);
+	DEBUG_ADD_FILE(pagetable);
+	DEBUG_ADD_FILE_RO(mmap);
+	DEBUG_ADD_FILE(mem);
+
+	return 0;
+}
+
+static int __init iommu_debug_init(void)
+{
+	struct dentry *d;
+	int err;
+
+	d = debugfs_create_dir("iommu", NULL);
+	if (!d)
+		return -ENOMEM;
+	iommu_debug_root = d;
+
+	err = foreach_iommu_device(d, iommu_debug_register);
+	if (err)
+		goto err_out;
+	return 0;
+
+err_out:
+	debugfs_remove_recursive(iommu_debug_root);
+	return err;
+}
+module_init(iommu_debug_init)
+
+static void __exit iommu_debugfs_exit(void)
+{
+	debugfs_remove_recursive(iommu_debug_root);
+}
+module_exit(iommu_debugfs_exit)
+
+MODULE_DESCRIPTION("omap iommu: debugfs interface");
+MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU@nokia.com>");
+MODULE_LICENSE("GPL v2");