/*
   * 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/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
  ";			\
  		const int maxcol = 32;					\
  		bytes = snprintf(p, maxcol, str, __stringify(name),	\
  				 iommu_read_reg(obj, MMU_##name));	\
  		p += bytes;						\
  		len -= bytes;						\
  		if (len < maxcol)					\
  			goto out;					\
  	} 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);

  	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, bytes);
  
  	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
  ", 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 debug_read_tlb(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
  ", "cam:", "ram:");
  	seq_puts(s, "-----------------------------------------
  ");
  	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
  ", 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
  ", da, *iopte);

  		}
  	}

  	spin_unlock(&obj->page_table_lock);

  }

  static int debug_read_pagetable(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
  ", "da:", "pte:");
  	seq_puts(s, "--------------------------
  ");
  	dump_ioptable(s);

  
  	mutex_unlock(&iommu_debug_lock);

  	return 0;

  }

  #define DEBUG_SEQ_FOPS_RO(name)						       \
  	static int debug_open_##name(struct inode *inode, struct file *file)   \
  	{								       \
  		return single_open(file, debug_read_##name, inode->i_private); \
  	}								       \
  									       \
  	static const struct file_operations debug_##name##_fops = {	       \
  		.open		= debug_open_##name,			       \
  		.read		= seq_read,				       \
  		.llseek		= seq_lseek,				       \
  		.release	= single_release,			       \
  	}

  #define DEBUG_FOPS_RO(name)						\
  	static const struct file_operations debug_##name##_fops = {	\

  		.open = simple_open,					\

  		.read = debug_read_##name,				\

  		.llseek = generic_file_llseek,				\

  	}

  DEBUG_FOPS_RO(regs);

  DEBUG_SEQ_FOPS_RO(tlb);

  DEBUG_SEQ_FOPS_RO(pagetable);

  
  #define __DEBUG_ADD_FILE(attr, mode)					\
  	{								\
  		struct dentry *dent;					\

  		dent = debugfs_create_file(#attr, mode, obj->debug_dir,	\
  					   obj, &debug_##attr##_fops);	\

  		if (!dent)						\

  			goto err;					\

  	}

  #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)

  void omap_iommu_debugfs_add(struct omap_iommu *obj)

  {

  	struct dentry *d;

  	if (!iommu_debug_root)
  		return;

  	obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
  	if (!obj->debug_dir)
  		return;

  	d = debugfs_create_u8("nr_tlb_entries", 0400, obj->debug_dir,

  			      (u8 *)&obj->nr_tlb_entries);
  	if (!d)

  		return;

  	DEBUG_ADD_FILE_RO(regs);
  	DEBUG_ADD_FILE_RO(tlb);

  	DEBUG_ADD_FILE_RO(pagetable);

  	return;

  err:
  	debugfs_remove_recursive(obj->debug_dir);

  }

  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);
  	if (!iommu_debug_root)
  		pr_err("can't create debugfs dir
  ");

  }

  void __exit omap_iommu_debugfs_exit(void)

  {

  	debugfs_remove(iommu_debug_root);

  }