[PATCH 00/17] OMAP IOMMU Cleanup & Consolidation

[PATCH 00/17] OMAP IOMMU Cleanup & Consolidation

[Suman Anna]

Hi,

The OMAP IOMMU driver is currently designed as three different
pieces - a core OMAP IOMMU driver that implements the generic
IOMMU API ops, a OMAP arch-specific layer that implements the
OMAP specific arch iommu_functions, and an independent debugfs
module. The former two are always built-in, while the last one
is tristate.

The driver supports OMAP2+ SoCs only, and this series performs
a whole lot of cleanup and consolidates all the above pieces
into a single built-in driver. The OMAP arch-specific layer is
eliminated completely (absorbed into the core OMAP driver), and
the debugfs portion is still maintained as a separate file, but
not a separate module anymore. This cleanup and consolidation
eliminates most of the currently exported functions from the
OMAP IOMMU driver.

The series also includes couple of fixes to the OMAP IOMMU
debugfs entries - permissions on one debugfs entry, eliminate
bus errors on debugfs access on disabled IOMMUs; and one
enhancement to list all valid page table entries instead of
listing only a page worth of data.

The patches are baselined on 3.17-rc3 and on top of the OMAP
IOMMU patches staged for 3.18 [1]; a reference branch with all
these patches is available is hosted at [2].

I am posting this series for review with the intention to have
them make it to 3.19, so I can repost once rc1 is out if needed.

[1] http://git.kernel.org/cgit/linux/kernel/git/joro/iommu.git/log/?h=arm/omap
[2] https://github.com/sumananna/omap-kernel/commits/iommu/submit/3.17-rc3-cleanup-consolidation

regards
Suman


Suman Anna (17):
  iommu/omap: Remove refcount field from omap_iommu object
  iommu/omap: Remove unused isr_priv field from omap_iommu
  iommu/omap: Remove duplicate declarations
  iommu/omap: Remove conditional definition of dev_to_omap_iommu()
  iommu/omap: Remove ver debugfs entry
  iommu/omap: Remove omap_iommu_arch_version() and version field
  iommu/omap: Remove bogus version check in context save/restore
  iommu/omap: Simplify omap2_iommu_fault_isr()
  iommu/omap: Consolidate OMAP IOMMU modules
  iommu/omap: Fix the permissions on nr_tlb_entries
  iommu/omap: Make pagetable debugfs entry read-only
  iommu/omap: Integrate omap-iommu-debug into omap-iommu
  iommu/omap: Remove couple of unused exported functions
  iommu/omap: Do not export unneeded functions
  iommu/omap: Reset the domain field upon detaching
  iommu/omap: Fix bus error on debugfs access of unattached IOMMU
  iommu/omap: Switch pagetable debugfs entry to use seq_file

 drivers/iommu/Kconfig            |   9 --
 drivers/iommu/Makefile           |   4 +-
 drivers/iommu/omap-iommu-debug.c | 244 ++++++++--------------------
 drivers/iommu/omap-iommu.c       | 304 ++++++++++++++++++++++-------------
 drivers/iommu/omap-iommu.h       |  90 +++++------
 drivers/iommu/omap-iommu2.c      | 337 ---------------------------------------
 6 files changed, 298 insertions(+), 690 deletions(-)
 delete mode 100644 drivers/iommu/omap-iommu2.c

-- 
2.1.0

[PATCH 01/17] iommu/omap: Remove refcount field from omap_iommu object

[Suman Anna]

The refcount field in omap_iommu object is primarily used to check
if an IOMMU device has already been enabled, but this is already
implicit in the omap_iommu_attach_dev() which ensures that only
a single device can attach to an IOMMU. This field is redundant,
and so has been cleaned up.

Signed-off-by: Suman Anna <s-anna-l0cyMroinI0@public.gmane.org>
---
 drivers/iommu/omap-iommu.c | 15 +++------------
 drivers/iommu/omap-iommu.h |  1 -
 2 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 4b432c4..ed26701 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -819,8 +819,9 @@ static irqreturn_t iommu_fault_handler(int irq, void *data)
 	u32 *iopgd, *iopte;
 	struct omap_iommu *obj = data;
 	struct iommu_domain *domain = obj->domain;
+	struct omap_iommu_domain *omap_domain = domain->priv;
 
-	if (!obj->refcount)
+	if (!omap_domain->iommu_dev)
 		return IRQ_NONE;
 
 	errs = iommu_report_fault(obj, &da);
@@ -880,13 +881,6 @@ static struct omap_iommu *omap_iommu_attach(const char *name, u32 *iopgd)
 
 	spin_lock(&obj->iommu_lock);
 
-	/* an iommu device can only be attached once */
-	if (++obj->refcount > 1) {
-		dev_err(dev, "%s: already attached!\n", obj->name);
-		err = -EBUSY;
-		goto err_enable;
-	}
-
 	obj->iopgd = iopgd;
 	err = iommu_enable(obj);
 	if (err)
@@ -899,7 +893,6 @@ static struct omap_iommu *omap_iommu_attach(const char *name, u32 *iopgd)
 	return obj;
 
 err_enable:
-	obj->refcount--;
 	spin_unlock(&obj->iommu_lock);
 	return ERR_PTR(err);
 }
@@ -915,9 +908,7 @@ static void omap_iommu_detach(struct omap_iommu *obj)
 
 	spin_lock(&obj->iommu_lock);
 
-	if (--obj->refcount == 0)
-		iommu_disable(obj);
-
+	iommu_disable(obj);
 	obj->iopgd = NULL;
 
 	spin_unlock(&obj->iommu_lock);
diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
index 4f1b68c..5c14000 100644
--- a/drivers/iommu/omap-iommu.h
+++ b/drivers/iommu/omap-iommu.h
@@ -33,7 +33,6 @@ struct omap_iommu {
 	void		*isr_priv;
 	struct iommu_domain *domain;
 
-	unsigned int	refcount;
 	spinlock_t	iommu_lock;	/* global for this whole object */
 
 	/*
-- 
2.1.0

[PATCH 02/17] iommu/omap: Remove unused isr_priv field from omap_iommu

[Suman Anna]

The isr_priv field is a left-over from before the IOMMU API
adaptation, this was used to store the callback data. This is
no longer relevant, so remove it.

Signed-off-by: Suman Anna <s-anna-l0cyMroinI0@public.gmane.org>
---
 drivers/iommu/omap-iommu.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
index 5c14000..18a0f3a 100644
--- a/drivers/iommu/omap-iommu.h
+++ b/drivers/iommu/omap-iommu.h
@@ -30,7 +30,6 @@ struct omap_iommu {
 	const char	*name;
 	void __iomem	*regbase;
 	struct device	*dev;
-	void		*isr_priv;
 	struct iommu_domain *domain;
 
 	spinlock_t	iommu_lock;	/* global for this whole object */
-- 
2.1.0

[PATCH 03/17] iommu/omap: Remove duplicate declarations

[Suman Anna]

The omap_iommu_save_ctx() and omap_iommu_restore_ctx() declarations
are defined in include/linux/omap-iommu.h and do not belong in the
internal drivers/iommu/omap-iommu.h header, so remove them.

Signed-off-by: Suman Anna <s-anna-l0cyMroinI0@public.gmane.org>
---
 drivers/iommu/omap-iommu.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
index 18a0f3a..4fc51c8 100644
--- a/drivers/iommu/omap-iommu.h
+++ b/drivers/iommu/omap-iommu.h
@@ -197,9 +197,6 @@ extern void omap_iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e);
 extern int
 omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e);
 
-extern void omap_iommu_save_ctx(struct device *dev);
-extern void omap_iommu_restore_ctx(struct device *dev);
-
 extern int omap_foreach_iommu_device(void *data,
 				int (*fn)(struct device *, void *));
 
-- 
2.1.0

[PATCH 04/17] iommu/omap: Remove conditional definition of dev_to_omap_iommu()

[Suman Anna]

The dev_to_omap_iommu() is local to the OMAP IOMMU modules, and
need not be defined conditionally. The CONFIG_IOMMU_API dependency
check was added in the past to fix a compilation issue back when
the header resided in the arch/arm layers, and is no longer
needed.

While at this, fix the header against double inclusion as well.

Signed-off-by: Suman Anna <s-anna-l0cyMroinI0@public.gmane.org>
---
 drivers/iommu/omap-iommu.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
index 4fc51c8..d7c5132 100644
--- a/drivers/iommu/omap-iommu.h
+++ b/drivers/iommu/omap-iommu.h
@@ -10,6 +10,9 @@
  * published by the Free Software Foundation.
  */
 
+#ifndef _OMAP_IOMMU_H
+#define _OMAP_IOMMU_H
+
 #if defined(CONFIG_ARCH_OMAP1)
 #error "iommu for this processor not implemented yet"
 #endif
@@ -92,7 +95,6 @@ struct iommu_functions {
 	ssize_t (*dump_ctx)(struct omap_iommu *obj, char *buf, ssize_t len);
 };
 
-#ifdef CONFIG_IOMMU_API
 /**
  * dev_to_omap_iommu() - retrieves an omap iommu object from a user device
  * @dev: iommu client device
@@ -103,7 +105,6 @@ static inline struct omap_iommu *dev_to_omap_iommu(struct device *dev)
 
 	return arch_data->iommu_dev;
 }
-#endif
 
 /*
  * MMU Register offsets
@@ -220,3 +221,5 @@ static inline void iommu_write_reg(struct omap_iommu *obj, u32 val, size_t offs)
 {
 	__raw_writel(val, obj->regbase + offs);
 }
+
+#endif /* _OMAP_IOMMU_H */
-- 
2.1.0

[PATCH 11/17] iommu/omap: Make pagetable debugfs entry read-only

[Suman Anna]

Remove the writeability on the 'pagetable' debugfs entry,
so that the mapping/unmapping into an OMAP IOMMU is only
limited to actual client devices/drivers at kernel-level.

Signed-off-by: Suman Anna <s-anna-l0cyMroinI0@public.gmane.org>
---
 drivers/iommu/omap-iommu-debug.c | 48 ++--------------------------------------
 1 file changed, 2 insertions(+), 46 deletions(-)

diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c
index a520438..28de657 100644
--- a/drivers/iommu/omap-iommu-debug.c
+++ b/drivers/iommu/omap-iommu-debug.c
@@ -24,8 +24,6 @@
 #include "omap-iopgtable.h"
 #include "omap-iommu.h"
 
-#define MAXCOLUMN 100 /* for short messages */
-
 static DEFINE_MUTEX(iommu_debug_lock);
 
 static struct dentry *iommu_debug_root;
@@ -82,39 +80,6 @@ static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
 	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 device *dev = file->private_data;
-	struct omap_iommu *obj = dev_to_omap_iommu(dev);
-	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;
-	}
-
-	omap_iotlb_cr_to_e(&cr, &e);
-	err = omap_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;
-}
-
 #define dump_ioptable_entry_one(lv, da, val)			\
 	({							\
 		int __err = 0;					\
@@ -202,14 +167,6 @@ static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
 	return bytes;
 }
 
-#define DEBUG_FOPS(name)						\
-	static const struct file_operations debug_##name##_fops = {	\
-		.open = simple_open,					\
-		.read = debug_read_##name,				\
-		.write = debug_write_##name,				\
-		.llseek = generic_file_llseek,				\
-	};
-
 #define DEBUG_FOPS_RO(name)						\
 	static const struct file_operations debug_##name##_fops = {	\
 		.open = simple_open,					\
@@ -219,7 +176,7 @@ static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
 
 DEBUG_FOPS_RO(regs);
 DEBUG_FOPS_RO(tlb);
-DEBUG_FOPS(pagetable);
+DEBUG_FOPS_RO(pagetable);
 
 #define __DEBUG_ADD_FILE(attr, mode)					\
 	{								\
@@ -230,7 +187,6 @@ DEBUG_FOPS(pagetable);
 			return -ENOMEM;					\
 	}
 
-#define DEBUG_ADD_FILE(name) __DEBUG_ADD_FILE(name, 0600)
 #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
 
 static int iommu_debug_register(struct device *dev, void *data)
@@ -263,7 +219,7 @@ static int iommu_debug_register(struct device *dev, void *data)
 
 	DEBUG_ADD_FILE_RO(regs);
 	DEBUG_ADD_FILE_RO(tlb);
-	DEBUG_ADD_FILE(pagetable);
+	DEBUG_ADD_FILE_RO(pagetable);
 
 	return 0;
 
-- 
2.1.0

[PATCH 15/17] iommu/omap: Reset the domain field upon detaching

[Suman Anna]

The .domain field in omap_iommu struct is set properly when the
OMAP IOMMU device is attached to, but is never reset properly
on detach. Reset this properly so that the OMAP IOMMU debugfs
logic can depend on this field before allowing the debugfs
operations.

Signed-off-by: Suman Anna <s-anna-l0cyMroinI0@public.gmane.org>
---
 drivers/iommu/omap-iommu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index a140873..3769dc0 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -1202,6 +1202,7 @@ static void _omap_iommu_detach_dev(struct omap_iommu_domain *omap_domain,
 
 	omap_domain->iommu_dev = arch_data->iommu_dev = NULL;
 	omap_domain->dev = NULL;
+	oiommu->domain = NULL;
 }
 
 static void omap_iommu_detach_dev(struct iommu_domain *domain,
-- 
2.1.0

[PATCH 05/17] iommu/omap: Remove ver debugfs entry

[Suman Anna]

The debugfs entry 'ver' to read the OMAP IOMMU version is
not much useful for developers, so it has been removed. The
same can be deduced from the register dump, provided by the
debugfs entry 'regs', REVISION register. This also allows us
to remove the omap_iommu_arch_revision() which is currently
returning a fixed value.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/omap-iommu-debug.c | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c
index 531658d..0fb92aa 100644
--- a/drivers/iommu/omap-iommu-debug.c
+++ b/drivers/iommu/omap-iommu-debug.c
@@ -30,17 +30,6 @@ static DEFINE_MUTEX(iommu_debug_lock);
 
 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 = omap_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)
 {
@@ -228,7 +217,6 @@ static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
 		.llseek = generic_file_llseek,				\
 	};
 
-DEBUG_FOPS_RO(ver);
 DEBUG_FOPS_RO(regs);
 DEBUG_FOPS_RO(tlb);
 DEBUG_FOPS(pagetable);
@@ -273,7 +261,6 @@ static int iommu_debug_register(struct device *dev, void *data)
 	if (!d)
 		goto nomem;
 
-	DEBUG_ADD_FILE_RO(ver);
 	DEBUG_ADD_FILE_RO(regs);
 	DEBUG_ADD_FILE_RO(tlb);
 	DEBUG_ADD_FILE(pagetable);
-- 
2.1.0

[PATCH 06/17] iommu/omap: Remove omap_iommu_arch_version() and version field

[Suman Anna]

The function omap_iommu_arch_version() is not used anymore,
and is not required either, so remove it. The .version field
in struct iommu_functions that this function uses is also
removed, as it is not really an ops to retrieve a version and
there won't be any usage for this field either.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/omap-iommu.c  | 9 ---------
 drivers/iommu/omap-iommu.h  | 4 ----
 drivers/iommu/omap-iommu2.c | 2 --
 3 files changed, 15 deletions(-)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index ed26701..332bfb9 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -138,15 +138,6 @@ void omap_iommu_restore_ctx(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(omap_iommu_restore_ctx);
 
-/**
- * omap_iommu_arch_version - Return running iommu arch version
- **/
-u32 omap_iommu_arch_version(void)
-{
-	return arch_iommu->version;
-}
-EXPORT_SYMBOL_GPL(omap_iommu_arch_version);
-
 static int iommu_enable(struct omap_iommu *obj)
 {
 	int err;
diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
index d7c5132..45fe67d 100644
--- a/drivers/iommu/omap-iommu.h
+++ b/drivers/iommu/omap-iommu.h
@@ -70,8 +70,6 @@ struct cr_regs {
 
 /* architecture specific functions */
 struct iommu_functions {
-	unsigned long	version;
-
 	int (*enable)(struct omap_iommu *obj);
 	void (*disable)(struct omap_iommu *obj);
 	void (*set_twl)(struct omap_iommu *obj, bool on);
@@ -191,8 +189,6 @@ static inline struct omap_iommu *dev_to_omap_iommu(struct device *dev)
 /*
  * global functions
  */
-extern u32 omap_iommu_arch_version(void);
-
 extern void omap_iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e);
 
 extern int
diff --git a/drivers/iommu/omap-iommu2.c b/drivers/iommu/omap-iommu2.c
index 5e1ea3b..2f6a9f7 100644
--- a/drivers/iommu/omap-iommu2.c
+++ b/drivers/iommu/omap-iommu2.c
@@ -297,8 +297,6 @@ static void omap2_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
 }
 
 static const struct iommu_functions omap2_iommu_ops = {
-	.version	= IOMMU_ARCH_VERSION,
-
 	.enable		= omap2_iommu_enable,
 	.disable	= omap2_iommu_disable,
 	.set_twl	= omap2_iommu_set_twl,
-- 
2.1.0

[PATCH 07/17] iommu/omap: Remove bogus version check in context save/restore

[Suman Anna]

The omap2_iommu_save_ctx() and omap2_iommu_restore_ctx()
performs a sanity version check against a fixed value
that is correct only for OMAP2/OMAP3 IOMMUs. This fixed check
does not scale for all OMAP2+ IOMMUs and is not absolutely
required, so it has been removed.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/omap-iommu2.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/iommu/omap-iommu2.c b/drivers/iommu/omap-iommu2.c
index 2f6a9f7..372141b 100644
--- a/drivers/iommu/omap-iommu2.c
+++ b/drivers/iommu/omap-iommu2.c
@@ -26,8 +26,6 @@
 /*
  * omap2 architecture specific register bit definitions
  */
-#define IOMMU_ARCH_VERSION	0x00000011
-
 /* IRQSTATUS & IRQENABLE */
 #define MMU_IRQ_MULTIHITFAULT	(1 << 4)
 #define MMU_IRQ_TABLEWALKFAULT	(1 << 3)
@@ -268,8 +266,6 @@ static void omap2_iommu_save_ctx(struct omap_iommu *obj)
 		p[i] = iommu_read_reg(obj, i * sizeof(u32));
 		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
 	}
-
-	BUG_ON(p[0] != IOMMU_ARCH_VERSION);
 }
 
 static void omap2_iommu_restore_ctx(struct omap_iommu *obj)
@@ -281,8 +277,6 @@ static void omap2_iommu_restore_ctx(struct omap_iommu *obj)
 		iommu_write_reg(obj, p[i], i * sizeof(u32));
 		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
 	}
-
-	BUG_ON(p[0] != IOMMU_ARCH_VERSION);
 }
 
 static void omap2_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
-- 
2.1.0

[PATCH 08/17] iommu/omap: Simplify omap2_iommu_fault_isr()

[Suman Anna]

The function omap2_iommu_fault_isr() does an unnecessary
recomputation of the return value. The logic relies on
setting the same bit fields as the MMU fault error status
bits, so simplify this function and remove the unneeded
macros. These macros were originally exported to notify
MMU faults to users prior to the IOMMU framework adaptation,
but are now redundant.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/omap-iommu2.c | 20 +-------------------
 1 file changed, 1 insertion(+), 19 deletions(-)

diff --git a/drivers/iommu/omap-iommu2.c b/drivers/iommu/omap-iommu2.c
index 372141b..ce2fff3 100644
--- a/drivers/iommu/omap-iommu2.c
+++ b/drivers/iommu/omap-iommu2.c
@@ -53,13 +53,6 @@
 	 ((pgsz) == MMU_CAM_PGSZ_64K) ? 0xffff0000 :	\
 	 ((pgsz) == MMU_CAM_PGSZ_4K)  ? 0xfffff000 : 0)
 
-/* IOMMU errors */
-#define OMAP_IOMMU_ERR_TLB_MISS		(1 << 0)
-#define OMAP_IOMMU_ERR_TRANS_FAULT	(1 << 1)
-#define OMAP_IOMMU_ERR_EMU_MISS		(1 << 2)
-#define OMAP_IOMMU_ERR_TBLWALK_FAULT	(1 << 3)
-#define OMAP_IOMMU_ERR_MULTIHIT_FAULT	(1 << 4)
-
 static void __iommu_set_twl(struct omap_iommu *obj, bool on)
 {
 	u32 l = iommu_read_reg(obj, MMU_CNTL);
@@ -122,7 +115,6 @@ static void omap2_iommu_set_twl(struct omap_iommu *obj, bool on)
 static u32 omap2_iommu_fault_isr(struct omap_iommu *obj, u32 *ra)
 {
 	u32 stat, da;
-	u32 errs = 0;
 
 	stat = iommu_read_reg(obj, MMU_IRQSTATUS);
 	stat &= MMU_IRQ_MASK;
@@ -134,19 +126,9 @@ static u32 omap2_iommu_fault_isr(struct omap_iommu *obj, u32 *ra)
 	da = iommu_read_reg(obj, MMU_FAULT_AD);
 	*ra = da;
 
-	if (stat & MMU_IRQ_TLBMISS)
-		errs |= OMAP_IOMMU_ERR_TLB_MISS;
-	if (stat & MMU_IRQ_TRANSLATIONFAULT)
-		errs |= OMAP_IOMMU_ERR_TRANS_FAULT;
-	if (stat & MMU_IRQ_EMUMISS)
-		errs |= OMAP_IOMMU_ERR_EMU_MISS;
-	if (stat & MMU_IRQ_TABLEWALKFAULT)
-		errs |= OMAP_IOMMU_ERR_TBLWALK_FAULT;
-	if (stat & MMU_IRQ_MULTIHITFAULT)
-		errs |= OMAP_IOMMU_ERR_MULTIHIT_FAULT;
 	iommu_write_reg(obj, stat, MMU_IRQSTATUS);
 
-	return errs;
+	return stat;
 }
 
 static void omap2_tlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
-- 
2.1.0

[PATCH 09/17] iommu/omap: Consolidate OMAP IOMMU modules

[Suman Anna]

The OMAP IOMMU driver was originally designed as modules, and split
into a core module and a thin arch-specific module through the OMAP
arch-specific struct iommu_functions, to scale for both OMAP1 and
OMAP2+ IOMMU variants. The driver can only be built for OMAP2+
platforms currently, and also can only be built-in after the
adaptation to generic IOMMU API. The OMAP1 variant was never added
and will most probably be never added (the code for the only potential
user, its parent, DSP processor has already been cleaned up). So,
consolidate the OMAP2 specific omap-iommu2 module into the core OMAP
IOMMU driver - this eliminates the arch-specific ops structure and
simplifies the driver into a single module that only implements the
generic IOMMU API's iommu_ops.

The following are the main changes:
- omap-iommu2 module is completely eliminated, with the common
  definitions moved to the internal omap-iommu.h, and the ops
  implementations moved into omap-iommu.c
- OMAP arch-specific struct iommu_functions is also eliminated,
  with the ops implementations directly absorbed into the calling
  functions
- iotlb_alloc_cr() is no longer inlined and defined only when
  PREFETCH_IOTLB is defined
- iotlb_dump_cr() is similarly defined only when CONFIG_OMAP_IOMMU_DEBUG
  is defined
- Elimination of the OMAP IOMMU exported functions to register the
  arch ops, omap_install_iommu_arch() & omap_uninstall_iommu_arch()
- Any stale comments about OMAP1 are also cleaned up

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/Makefile      |   1 -
 drivers/iommu/omap-iommu.c  | 263 ++++++++++++++++++++++++++-----------
 drivers/iommu/omap-iommu.h  |  61 +++++----
 drivers/iommu/omap-iommu2.c | 311 --------------------------------------------
 4 files changed, 217 insertions(+), 419 deletions(-)
 delete mode 100644 drivers/iommu/omap-iommu2.c

diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 16edef7..18fa446 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -11,7 +11,6 @@ obj-$(CONFIG_INTEL_IOMMU) += iova.o intel-iommu.o
 obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
 obj-$(CONFIG_IRQ_REMAP) += intel_irq_remapping.o irq_remapping.o
 obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
-obj-$(CONFIG_OMAP_IOMMU) += omap-iommu2.o
 obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o
 obj-$(CONFIG_TEGRA_IOMMU_GART) += tegra-gart.o
 obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o
diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 332bfb9..9ace5557 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -76,53 +76,23 @@ struct iotlb_lock {
 	short vict;
 };
 
-/* accommodate the difference between omap1 and omap2/3 */
-static const struct iommu_functions *arch_iommu;
-
 static struct platform_driver omap_iommu_driver;
 static struct kmem_cache *iopte_cachep;
 
 /**
- * omap_install_iommu_arch - Install archtecure specific iommu functions
- * @ops:	a pointer to architecture specific iommu functions
- *
- * There are several kind of iommu algorithm(tlb, pagetable) among
- * omap series. This interface installs such an iommu algorighm.
- **/
-int omap_install_iommu_arch(const struct iommu_functions *ops)
-{
-	if (arch_iommu)
-		return -EBUSY;
-
-	arch_iommu = ops;
-	return 0;
-}
-EXPORT_SYMBOL_GPL(omap_install_iommu_arch);
-
-/**
- * omap_uninstall_iommu_arch - Uninstall archtecure specific iommu functions
- * @ops:	a pointer to architecture specific iommu functions
- *
- * This interface uninstalls the iommu algorighm installed previously.
- **/
-void omap_uninstall_iommu_arch(const struct iommu_functions *ops)
-{
-	if (arch_iommu != ops)
-		pr_err("%s: not your arch\n", __func__);
-
-	arch_iommu = NULL;
-}
-EXPORT_SYMBOL_GPL(omap_uninstall_iommu_arch);
-
-/**
  * omap_iommu_save_ctx - Save registers for pm off-mode support
  * @dev:	client device
  **/
 void omap_iommu_save_ctx(struct device *dev)
 {
 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
+	u32 *p = obj->ctx;
+	int i;
 
-	arch_iommu->save_ctx(obj);
+	for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
+		p[i] = iommu_read_reg(obj, i * sizeof(u32));
+		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
+	}
 }
 EXPORT_SYMBOL_GPL(omap_iommu_save_ctx);
 
@@ -133,20 +103,75 @@ EXPORT_SYMBOL_GPL(omap_iommu_save_ctx);
 void omap_iommu_restore_ctx(struct device *dev)
 {
 	struct omap_iommu *obj = dev_to_omap_iommu(dev);
+	u32 *p = obj->ctx;
+	int i;
 
-	arch_iommu->restore_ctx(obj);
+	for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
+		iommu_write_reg(obj, p[i], i * sizeof(u32));
+		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
+	}
 }
 EXPORT_SYMBOL_GPL(omap_iommu_restore_ctx);
 
+static void __iommu_set_twl(struct omap_iommu *obj, bool on)
+{
+	u32 l = iommu_read_reg(obj, MMU_CNTL);
+
+	if (on)
+		iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
+	else
+		iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
+
+	l &= ~MMU_CNTL_MASK;
+	if (on)
+		l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
+	else
+		l |= (MMU_CNTL_MMU_EN);
+
+	iommu_write_reg(obj, l, MMU_CNTL);
+}
+
+static int omap2_iommu_enable(struct omap_iommu *obj)
+{
+	u32 l, pa;
+
+	if (!obj->iopgd || !IS_ALIGNED((u32)obj->iopgd,  SZ_16K))
+		return -EINVAL;
+
+	pa = virt_to_phys(obj->iopgd);
+	if (!IS_ALIGNED(pa, SZ_16K))
+		return -EINVAL;
+
+	l = iommu_read_reg(obj, MMU_REVISION);
+	dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
+		 (l >> 4) & 0xf, l & 0xf);
+
+	iommu_write_reg(obj, pa, MMU_TTB);
+
+	if (obj->has_bus_err_back)
+		iommu_write_reg(obj, MMU_GP_REG_BUS_ERR_BACK_EN, MMU_GP_REG);
+
+	__iommu_set_twl(obj, true);
+
+	return 0;
+}
+
+static void omap2_iommu_disable(struct omap_iommu *obj)
+{
+	u32 l = iommu_read_reg(obj, MMU_CNTL);
+
+	l &= ~MMU_CNTL_MASK;
+	iommu_write_reg(obj, l, MMU_CNTL);
+
+	dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
+}
+
 static int iommu_enable(struct omap_iommu *obj)
 {
 	int err;
 	struct platform_device *pdev = to_platform_device(obj->dev);
 	struct iommu_platform_data *pdata = pdev->dev.platform_data;
 
-	if (!arch_iommu)
-		return -ENODEV;
-
 	if (pdata && pdata->deassert_reset) {
 		err = pdata->deassert_reset(pdev, pdata->reset_name);
 		if (err) {
@@ -157,7 +182,7 @@ static int iommu_enable(struct omap_iommu *obj)
 
 	pm_runtime_get_sync(obj->dev);
 
-	err = arch_iommu->enable(obj);
+	err = omap2_iommu_enable(obj);
 
 	return err;
 }
@@ -167,7 +192,7 @@ static void iommu_disable(struct omap_iommu *obj)
 	struct platform_device *pdev = to_platform_device(obj->dev);
 	struct iommu_platform_data *pdata = pdev->dev.platform_data;
 
-	arch_iommu->disable(obj);
+	omap2_iommu_disable(obj);
 
 	pm_runtime_put_sync(obj->dev);
 
@@ -182,7 +207,13 @@ void omap_iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
 {
 	BUG_ON(!cr || !e);
 
-	arch_iommu->cr_to_e(cr, e);
+	e->da		= cr->cam & MMU_CAM_VATAG_MASK;
+	e->pa		= cr->ram & MMU_RAM_PADDR_MASK;
+	e->valid	= cr->cam & MMU_CAM_V;
+	e->pgsz		= cr->cam & MMU_CAM_PGSZ_MASK;
+	e->endian	= cr->ram & MMU_RAM_ENDIAN_MASK;
+	e->elsz		= cr->ram & MMU_RAM_ELSZ_MASK;
+	e->mixed	= cr->ram & MMU_RAM_MIXED;
 }
 EXPORT_SYMBOL_GPL(omap_iotlb_cr_to_e);
 
@@ -191,31 +222,46 @@ static inline int iotlb_cr_valid(struct cr_regs *cr)
 	if (!cr)
 		return -EINVAL;
 
-	return arch_iommu->cr_valid(cr);
-}
-
-static inline struct cr_regs *iotlb_alloc_cr(struct omap_iommu *obj,
-					     struct iotlb_entry *e)
-{
-	if (!e)
-		return NULL;
-
-	return arch_iommu->alloc_cr(obj, e);
+	return cr->cam & MMU_CAM_V;
 }
 
 static u32 iotlb_cr_to_virt(struct cr_regs *cr)
 {
-	return arch_iommu->cr_to_virt(cr);
+	u32 page_size = cr->cam & MMU_CAM_PGSZ_MASK;
+	u32 mask = get_cam_va_mask(cr->cam & page_size);
+
+	return cr->cam & mask;
 }
 
 static u32 get_iopte_attr(struct iotlb_entry *e)
 {
-	return arch_iommu->get_pte_attr(e);
+	u32 attr;
+
+	attr = e->mixed << 5;
+	attr |= e->endian;
+	attr |= e->elsz >> 3;
+	attr <<= (((e->pgsz == MMU_CAM_PGSZ_4K) ||
+			(e->pgsz == MMU_CAM_PGSZ_64K)) ? 0 : 6);
+	return attr;
 }
 
 static u32 iommu_report_fault(struct omap_iommu *obj, u32 *da)
 {
-	return arch_iommu->fault_isr(obj, da);
+	u32 status, fault_addr;
+
+	status = iommu_read_reg(obj, MMU_IRQSTATUS);
+	status &= MMU_IRQ_MASK;
+	if (!status) {
+		*da = 0;
+		return 0;
+	}
+
+	fault_addr = iommu_read_reg(obj, MMU_FAULT_AD);
+	*da = fault_addr;
+
+	iommu_write_reg(obj, status, MMU_IRQSTATUS);
+
+	return status;
 }
 
 static void iotlb_lock_get(struct omap_iommu *obj, struct iotlb_lock *l)
@@ -241,31 +287,19 @@ static void iotlb_lock_set(struct omap_iommu *obj, struct iotlb_lock *l)
 
 static void iotlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
 {
-	arch_iommu->tlb_read_cr(obj, cr);
+	cr->cam = iommu_read_reg(obj, MMU_READ_CAM);
+	cr->ram = iommu_read_reg(obj, MMU_READ_RAM);
 }
 
 static void iotlb_load_cr(struct omap_iommu *obj, struct cr_regs *cr)
 {
-	arch_iommu->tlb_load_cr(obj, cr);
+	iommu_write_reg(obj, cr->cam | MMU_CAM_V, MMU_CAM);
+	iommu_write_reg(obj, cr->ram, MMU_RAM);
 
 	iommu_write_reg(obj, 1, MMU_FLUSH_ENTRY);
 	iommu_write_reg(obj, 1, MMU_LD_TLB);
 }
 
-/**
- * iotlb_dump_cr - Dump an iommu tlb entry into buf
- * @obj:	target iommu
- * @cr:		contents of cam and ram register
- * @buf:	output buffer
- **/
-static inline ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
-				    char *buf)
-{
-	BUG_ON(!cr || !buf);
-
-	return arch_iommu->dump_cr(obj, cr, buf);
-}
-
 /* only used in iotlb iteration for-loop */
 static struct cr_regs __iotlb_read_cr(struct omap_iommu *obj, int n)
 {
@@ -280,12 +314,36 @@ static struct cr_regs __iotlb_read_cr(struct omap_iommu *obj, int n)
 	return cr;
 }
 
+#ifdef PREFETCH_IOTLB
+static struct cr_regs *iotlb_alloc_cr(struct omap_iommu *obj,
+				      struct iotlb_entry *e)
+{
+	struct cr_regs *cr;
+
+	if (!e)
+		return NULL;
+
+	if (e->da & ~(get_cam_va_mask(e->pgsz))) {
+		dev_err(obj->dev, "%s:\twrong alignment: %08x\n", __func__,
+			e->da);
+		return ERR_PTR(-EINVAL);
+	}
+
+	cr = kmalloc(sizeof(*cr), GFP_KERNEL);
+	if (!cr)
+		return ERR_PTR(-ENOMEM);
+
+	cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
+	cr->ram = e->pa | e->endian | e->elsz | e->mixed;
+
+	return cr;
+}
+
 /**
  * load_iotlb_entry - Set an iommu tlb entry
  * @obj:	target iommu
  * @e:		an iommu tlb entry info
  **/
-#ifdef PREFETCH_IOTLB
 static int load_iotlb_entry(struct omap_iommu *obj, struct iotlb_entry *e)
 {
 	int err = 0;
@@ -416,6 +474,44 @@ static void flush_iotlb_all(struct omap_iommu *obj)
 
 #if defined(CONFIG_OMAP_IOMMU_DEBUG) || defined(CONFIG_OMAP_IOMMU_DEBUG_MODULE)
 
+#define pr_reg(name)							\
+	do {								\
+		ssize_t bytes;						\
+		const char *str = "%20s: %08x\n";			\
+		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;
+}
+
 ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t bytes)
 {
 	if (!obj || !buf)
@@ -423,7 +519,7 @@ ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t bytes)
 
 	pm_runtime_get_sync(obj->dev);
 
-	bytes = arch_iommu->dump_ctx(obj, buf, bytes);
+	bytes = omap2_iommu_dump_ctx(obj, buf, bytes);
 
 	pm_runtime_put_sync(obj->dev);
 
@@ -455,6 +551,24 @@ __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
 }
 
 /**
+ * iotlb_dump_cr - Dump an iommu tlb entry into buf
+ * @obj:	target iommu
+ * @cr:		contents of cam and ram register
+ * @buf:	output buffer
+ **/
+static ssize_t iotlb_dump_cr(struct omap_iommu *obj, struct cr_regs *cr,
+			     char *buf)
+{
+	char *p = buf;
+
+	/* FIXME: Need more detail analysis of cam/ram */
+	p += sprintf(p, "%08x %08x %01x\n", cr->cam, cr->ram,
+					(cr->cam & MMU_CAM_P) ? 1 : 0);
+
+	return p - buf;
+}
+
+/**
  * omap_dump_tlb_entries - dump cr arrays to given buffer
  * @obj:	target iommu
  * @buf:	output buffer
@@ -1008,7 +1122,6 @@ static u32 iotlb_init_entry(struct iotlb_entry *e, u32 da, u32 pa, int pgsz)
 	e->da		= da;
 	e->pa		= pa;
 	e->valid	= MMU_CAM_V;
-	/* FIXME: add OMAP1 support */
 	e->pgsz		= pgsz;
 	e->endian	= MMU_RAM_ENDIAN_LITTLE;
 	e->elsz		= MMU_RAM_ELSZ_8;
diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
index 45fe67d..0516e0e 100644
--- a/drivers/iommu/omap-iommu.h
+++ b/drivers/iommu/omap-iommu.h
@@ -13,10 +13,6 @@
 #ifndef _OMAP_IOMMU_H
 #define _OMAP_IOMMU_H
 
-#if defined(CONFIG_ARCH_OMAP1)
-#error "iommu for this processor not implemented yet"
-#endif
-
 struct iotlb_entry {
 	u32 da;
 	u32 pa;
@@ -68,31 +64,6 @@ struct cr_regs {
 	};
 };
 
-/* architecture specific functions */
-struct iommu_functions {
-	int (*enable)(struct omap_iommu *obj);
-	void (*disable)(struct omap_iommu *obj);
-	void (*set_twl)(struct omap_iommu *obj, bool on);
-	u32 (*fault_isr)(struct omap_iommu *obj, u32 *ra);
-
-	void (*tlb_read_cr)(struct omap_iommu *obj, struct cr_regs *cr);
-	void (*tlb_load_cr)(struct omap_iommu *obj, struct cr_regs *cr);
-
-	struct cr_regs *(*alloc_cr)(struct omap_iommu *obj,
-							struct iotlb_entry *e);
-	int (*cr_valid)(struct cr_regs *cr);
-	u32 (*cr_to_virt)(struct cr_regs *cr);
-	void (*cr_to_e)(struct cr_regs *cr, struct iotlb_entry *e);
-	ssize_t (*dump_cr)(struct omap_iommu *obj, struct cr_regs *cr,
-							char *buf);
-
-	u32 (*get_pte_attr)(struct iotlb_entry *e);
-
-	void (*save_ctx)(struct omap_iommu *obj);
-	void (*restore_ctx)(struct omap_iommu *obj);
-	ssize_t (*dump_ctx)(struct omap_iommu *obj, char *buf, ssize_t len);
-};
-
 /**
  * dev_to_omap_iommu() - retrieves an omap iommu object from a user device
  * @dev: iommu client device
@@ -130,6 +101,28 @@ static inline struct omap_iommu *dev_to_omap_iommu(struct device *dev)
 /*
  * MMU Register bit definitions
  */
+/* IRQSTATUS & IRQENABLE */
+#define MMU_IRQ_MULTIHITFAULT	(1 << 4)
+#define MMU_IRQ_TABLEWALKFAULT	(1 << 3)
+#define MMU_IRQ_EMUMISS		(1 << 2)
+#define MMU_IRQ_TRANSLATIONFAULT	(1 << 1)
+#define MMU_IRQ_TLBMISS		(1 << 0)
+
+#define __MMU_IRQ_FAULT		\
+	(MMU_IRQ_MULTIHITFAULT | MMU_IRQ_EMUMISS | MMU_IRQ_TRANSLATIONFAULT)
+#define MMU_IRQ_MASK		\
+	(__MMU_IRQ_FAULT | MMU_IRQ_TABLEWALKFAULT | MMU_IRQ_TLBMISS)
+#define MMU_IRQ_TWL_MASK	(__MMU_IRQ_FAULT | MMU_IRQ_TABLEWALKFAULT)
+#define MMU_IRQ_TLB_MISS_MASK	(__MMU_IRQ_FAULT | MMU_IRQ_TLBMISS)
+
+/* MMU_CNTL */
+#define MMU_CNTL_SHIFT		1
+#define MMU_CNTL_MASK		(7 << MMU_CNTL_SHIFT)
+#define MMU_CNTL_EML_TLB	(1 << 3)
+#define MMU_CNTL_TWL_EN		(1 << 2)
+#define MMU_CNTL_MMU_EN		(1 << 1)
+
+/* CAM */
 #define MMU_CAM_VATAG_SHIFT	12
 #define MMU_CAM_VATAG_MASK \
 	((~0UL >> MMU_CAM_VATAG_SHIFT) << MMU_CAM_VATAG_SHIFT)
@@ -141,6 +134,7 @@ static inline struct omap_iommu *dev_to_omap_iommu(struct device *dev)
 #define MMU_CAM_PGSZ_4K		(2 << 0)
 #define MMU_CAM_PGSZ_16M	(3 << 0)
 
+/* RAM */
 #define MMU_RAM_PADDR_SHIFT	12
 #define MMU_RAM_PADDR_MASK \
 	((~0UL >> MMU_RAM_PADDR_SHIFT) << MMU_RAM_PADDR_SHIFT)
@@ -162,6 +156,12 @@ static inline struct omap_iommu *dev_to_omap_iommu(struct device *dev)
 
 #define MMU_GP_REG_BUS_ERR_BACK_EN	0x1
 
+#define get_cam_va_mask(pgsz)				\
+	(((pgsz) == MMU_CAM_PGSZ_16M) ? 0xff000000 :	\
+	 ((pgsz) == MMU_CAM_PGSZ_1M)  ? 0xfff00000 :	\
+	 ((pgsz) == MMU_CAM_PGSZ_64K) ? 0xffff0000 :	\
+	 ((pgsz) == MMU_CAM_PGSZ_4K)  ? 0xfffff000 : 0)
+
 /*
  * utilities for super page(16MB, 1MB, 64KB and 4KB)
  */
@@ -197,9 +197,6 @@ omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e);
 extern int omap_foreach_iommu_device(void *data,
 				int (*fn)(struct device *, void *));
 
-extern int omap_install_iommu_arch(const struct iommu_functions *ops);
-extern void omap_uninstall_iommu_arch(const struct iommu_functions *ops);
-
 extern ssize_t
 omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len);
 extern size_t
diff --git a/drivers/iommu/omap-iommu2.c b/drivers/iommu/omap-iommu2.c
deleted file mode 100644
index ce2fff3..0000000
--- a/drivers/iommu/omap-iommu2.c
+++ /dev/null
@@ -1,311 +0,0 @@
-/*
- * omap iommu: omap2/3 architecture specific functions
- *
- * Copyright (C) 2008-2009 Nokia Corporation
- *
- * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>,
- *		Paul Mundt and Toshihiro Kobayashi
- *
- * 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/device.h>
-#include <linux/io.h>
-#include <linux/jiffies.h>
-#include <linux/module.h>
-#include <linux/omap-iommu.h>
-#include <linux/slab.h>
-#include <linux/stringify.h>
-#include <linux/platform_data/iommu-omap.h>
-
-#include "omap-iommu.h"
-
-/*
- * omap2 architecture specific register bit definitions
- */
-/* IRQSTATUS & IRQENABLE */
-#define MMU_IRQ_MULTIHITFAULT	(1 << 4)
-#define MMU_IRQ_TABLEWALKFAULT	(1 << 3)
-#define MMU_IRQ_EMUMISS		(1 << 2)
-#define MMU_IRQ_TRANSLATIONFAULT	(1 << 1)
-#define MMU_IRQ_TLBMISS		(1 << 0)
-
-#define __MMU_IRQ_FAULT		\
-	(MMU_IRQ_MULTIHITFAULT | MMU_IRQ_EMUMISS | MMU_IRQ_TRANSLATIONFAULT)
-#define MMU_IRQ_MASK		\
-	(__MMU_IRQ_FAULT | MMU_IRQ_TABLEWALKFAULT | MMU_IRQ_TLBMISS)
-#define MMU_IRQ_TWL_MASK	(__MMU_IRQ_FAULT | MMU_IRQ_TABLEWALKFAULT)
-#define MMU_IRQ_TLB_MISS_MASK	(__MMU_IRQ_FAULT | MMU_IRQ_TLBMISS)
-
-/* MMU_CNTL */
-#define MMU_CNTL_SHIFT		1
-#define MMU_CNTL_MASK		(7 << MMU_CNTL_SHIFT)
-#define MMU_CNTL_EML_TLB	(1 << 3)
-#define MMU_CNTL_TWL_EN		(1 << 2)
-#define MMU_CNTL_MMU_EN		(1 << 1)
-
-#define get_cam_va_mask(pgsz)				\
-	(((pgsz) == MMU_CAM_PGSZ_16M) ? 0xff000000 :	\
-	 ((pgsz) == MMU_CAM_PGSZ_1M)  ? 0xfff00000 :	\
-	 ((pgsz) == MMU_CAM_PGSZ_64K) ? 0xffff0000 :	\
-	 ((pgsz) == MMU_CAM_PGSZ_4K)  ? 0xfffff000 : 0)
-
-static void __iommu_set_twl(struct omap_iommu *obj, bool on)
-{
-	u32 l = iommu_read_reg(obj, MMU_CNTL);
-
-	if (on)
-		iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
-	else
-		iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
-
-	l &= ~MMU_CNTL_MASK;
-	if (on)
-		l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
-	else
-		l |= (MMU_CNTL_MMU_EN);
-
-	iommu_write_reg(obj, l, MMU_CNTL);
-}
-
-
-static int omap2_iommu_enable(struct omap_iommu *obj)
-{
-	u32 l, pa;
-
-	if (!obj->iopgd || !IS_ALIGNED((u32)obj->iopgd,  SZ_16K))
-		return -EINVAL;
-
-	pa = virt_to_phys(obj->iopgd);
-	if (!IS_ALIGNED(pa, SZ_16K))
-		return -EINVAL;
-
-	l = iommu_read_reg(obj, MMU_REVISION);
-	dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
-		 (l >> 4) & 0xf, l & 0xf);
-
-	iommu_write_reg(obj, pa, MMU_TTB);
-
-	if (obj->has_bus_err_back)
-		iommu_write_reg(obj, MMU_GP_REG_BUS_ERR_BACK_EN, MMU_GP_REG);
-
-	__iommu_set_twl(obj, true);
-
-	return 0;
-}
-
-static void omap2_iommu_disable(struct omap_iommu *obj)
-{
-	u32 l = iommu_read_reg(obj, MMU_CNTL);
-
-	l &= ~MMU_CNTL_MASK;
-	iommu_write_reg(obj, l, MMU_CNTL);
-
-	dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
-}
-
-static void omap2_iommu_set_twl(struct omap_iommu *obj, bool on)
-{
-	__iommu_set_twl(obj, false);
-}
-
-static u32 omap2_iommu_fault_isr(struct omap_iommu *obj, u32 *ra)
-{
-	u32 stat, da;
-
-	stat = iommu_read_reg(obj, MMU_IRQSTATUS);
-	stat &= MMU_IRQ_MASK;
-	if (!stat) {
-		*ra = 0;
-		return 0;
-	}
-
-	da = iommu_read_reg(obj, MMU_FAULT_AD);
-	*ra = da;
-
-	iommu_write_reg(obj, stat, MMU_IRQSTATUS);
-
-	return stat;
-}
-
-static void omap2_tlb_read_cr(struct omap_iommu *obj, struct cr_regs *cr)
-{
-	cr->cam = iommu_read_reg(obj, MMU_READ_CAM);
-	cr->ram = iommu_read_reg(obj, MMU_READ_RAM);
-}
-
-static void omap2_tlb_load_cr(struct omap_iommu *obj, struct cr_regs *cr)
-{
-	iommu_write_reg(obj, cr->cam | MMU_CAM_V, MMU_CAM);
-	iommu_write_reg(obj, cr->ram, MMU_RAM);
-}
-
-static u32 omap2_cr_to_virt(struct cr_regs *cr)
-{
-	u32 page_size = cr->cam & MMU_CAM_PGSZ_MASK;
-	u32 mask = get_cam_va_mask(cr->cam & page_size);
-
-	return cr->cam & mask;
-}
-
-static struct cr_regs *omap2_alloc_cr(struct omap_iommu *obj,
-						struct iotlb_entry *e)
-{
-	struct cr_regs *cr;
-
-	if (e->da & ~(get_cam_va_mask(e->pgsz))) {
-		dev_err(obj->dev, "%s:\twrong alignment: %08x\n", __func__,
-			e->da);
-		return ERR_PTR(-EINVAL);
-	}
-
-	cr = kmalloc(sizeof(*cr), GFP_KERNEL);
-	if (!cr)
-		return ERR_PTR(-ENOMEM);
-
-	cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
-	cr->ram = e->pa | e->endian | e->elsz | e->mixed;
-
-	return cr;
-}
-
-static inline int omap2_cr_valid(struct cr_regs *cr)
-{
-	return cr->cam & MMU_CAM_V;
-}
-
-static u32 omap2_get_pte_attr(struct iotlb_entry *e)
-{
-	u32 attr;
-
-	attr = e->mixed << 5;
-	attr |= e->endian;
-	attr |= e->elsz >> 3;
-	attr <<= (((e->pgsz == MMU_CAM_PGSZ_4K) ||
-			(e->pgsz == MMU_CAM_PGSZ_64K)) ? 0 : 6);
-	return attr;
-}
-
-static ssize_t
-omap2_dump_cr(struct omap_iommu *obj, struct cr_regs *cr, char *buf)
-{
-	char *p = buf;
-
-	/* FIXME: Need more detail analysis of cam/ram */
-	p += sprintf(p, "%08x %08x %01x\n", cr->cam, cr->ram,
-					(cr->cam & MMU_CAM_P) ? 1 : 0);
-
-	return p - buf;
-}
-
-#define pr_reg(name)							\
-	do {								\
-		ssize_t bytes;						\
-		const char *str = "%20s: %08x\n";			\
-		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 void omap2_iommu_save_ctx(struct omap_iommu *obj)
-{
-	int i;
-	u32 *p = obj->ctx;
-
-	for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
-		p[i] = iommu_read_reg(obj, i * sizeof(u32));
-		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
-	}
-}
-
-static void omap2_iommu_restore_ctx(struct omap_iommu *obj)
-{
-	int i;
-	u32 *p = obj->ctx;
-
-	for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
-		iommu_write_reg(obj, p[i], i * sizeof(u32));
-		dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
-	}
-}
-
-static void omap2_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
-{
-	e->da		= cr->cam & MMU_CAM_VATAG_MASK;
-	e->pa		= cr->ram & MMU_RAM_PADDR_MASK;
-	e->valid	= cr->cam & MMU_CAM_V;
-	e->pgsz		= cr->cam & MMU_CAM_PGSZ_MASK;
-	e->endian	= cr->ram & MMU_RAM_ENDIAN_MASK;
-	e->elsz		= cr->ram & MMU_RAM_ELSZ_MASK;
-	e->mixed	= cr->ram & MMU_RAM_MIXED;
-}
-
-static const struct iommu_functions omap2_iommu_ops = {
-	.enable		= omap2_iommu_enable,
-	.disable	= omap2_iommu_disable,
-	.set_twl	= omap2_iommu_set_twl,
-	.fault_isr	= omap2_iommu_fault_isr,
-
-	.tlb_read_cr	= omap2_tlb_read_cr,
-	.tlb_load_cr	= omap2_tlb_load_cr,
-
-	.cr_to_e	= omap2_cr_to_e,
-	.cr_to_virt	= omap2_cr_to_virt,
-	.alloc_cr	= omap2_alloc_cr,
-	.cr_valid	= omap2_cr_valid,
-	.dump_cr	= omap2_dump_cr,
-
-	.get_pte_attr	= omap2_get_pte_attr,
-
-	.save_ctx	= omap2_iommu_save_ctx,
-	.restore_ctx	= omap2_iommu_restore_ctx,
-	.dump_ctx	= omap2_iommu_dump_ctx,
-};
-
-static int __init omap2_iommu_init(void)
-{
-	return omap_install_iommu_arch(&omap2_iommu_ops);
-}
-module_init(omap2_iommu_init);
-
-static void __exit omap2_iommu_exit(void)
-{
-	omap_uninstall_iommu_arch(&omap2_iommu_ops);
-}
-module_exit(omap2_iommu_exit);
-
-MODULE_AUTHOR("Hiroshi DOYU, Paul Mundt and Toshihiro Kobayashi");
-MODULE_DESCRIPTION("omap iommu: omap2/3 architecture specific functions");
-MODULE_LICENSE("GPL v2");
-- 
2.1.0

[PATCH 10/17] iommu/omap: Fix the permissions on nr_tlb_entries

[Suman Anna]

The permissions on the debugfs entry "nr_tlb_entries" should
have been octal, not decimal, so fix it.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/omap-iommu-debug.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c
index 0fb92aa..a520438 100644
--- a/drivers/iommu/omap-iommu-debug.c
+++ b/drivers/iommu/omap-iommu-debug.c
@@ -256,7 +256,7 @@ static int iommu_debug_register(struct device *dev, void *data)
 		goto nomem;
 	parent = d;
 
-	d = debugfs_create_u8("nr_tlb_entries", 400, parent,
+	d = debugfs_create_u8("nr_tlb_entries", 0400, parent,
 			      (u8 *)&obj->nr_tlb_entries);
 	if (!d)
 		goto nomem;
-- 
2.1.0

[PATCH 12/17] iommu/omap: Integrate omap-iommu-debug into omap-iommu

[Suman Anna]

The debugfs support for OMAP IOMMU is currently implemented
as a module, warranting certain OMAP-specific IOMMU API to
be exported. The OMAP IOMMU, when enabled, can only be built-in
into the kernel, so integrate the OMAP IOMMU debug module
into the OMAP IOMMU driver. This helps in eliminating the
need to export most of the current OMAP IOMMU API.

The following are the main changes:
- The OMAP_IOMMU_DEBUG Kconfig option is eliminated, and
  the OMAP IOMMU debugfs support is built alongside the OMAP
  IOMMU driver, and enabled automatically only when debugfs
  is enabled.
- The debugfs directory and entry creation logic is reversed,
  the calls are invoked by the OMAP IOMMU driver now.
- The current iffy circular logic of adding IOMMU archdata
  to the IOMMU devices itself to get a pointer to the omap_iommu
  object in the debugfs support code is replaced by directly
  using the omap_iommu structure while creating the debugfs
  entries.
- The debugfs root directory is renamed from the generic name
  "iommu" to a specific name "omap_iommu".
- Unneeded headers have also been cleaned up while at this.
- There will no longer be a omap-iommu-debug.ko module after
  this patch.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/Kconfig            |   9 ----
 drivers/iommu/Makefile           |   3 +-
 drivers/iommu/omap-iommu-debug.c | 102 ++++++++++++---------------------------
 drivers/iommu/omap-iommu.c       |  11 +++--
 drivers/iommu/omap-iommu.h       |   7 +++
 5 files changed, 45 insertions(+), 87 deletions(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index dd51122..9724d4a 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -143,15 +143,6 @@ config OMAP_IOMMU
 	depends on ARCH_OMAP2PLUS
 	select IOMMU_API
 
-config OMAP_IOMMU_DEBUG
-       tristate "Export OMAP IOMMU internals in DebugFS"
-       depends on OMAP_IOMMU && DEBUG_FS
-       help
-         Select this to see extensive information about
-         the internal state of OMAP IOMMU in debugfs.
-
-         Say N unless you know you need this.
-
 config TEGRA_IOMMU_GART
 	bool "Tegra GART IOMMU Support"
 	depends on ARCH_TEGRA_2x_SOC
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 18fa446..e0a4fed 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -10,8 +10,7 @@ obj-$(CONFIG_DMAR_TABLE) += dmar.o
 obj-$(CONFIG_INTEL_IOMMU) += iova.o intel-iommu.o
 obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
 obj-$(CONFIG_IRQ_REMAP) += intel_irq_remapping.o irq_remapping.o
-obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
-obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o
+obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o omap-iommu-debug.o
 obj-$(CONFIG_TEGRA_IOMMU_GART) += tegra-gart.o
 obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o
 obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c
index 28de657..54a0dc6 100644
--- a/drivers/iommu/omap-iommu-debug.c
+++ b/drivers/iommu/omap-iommu-debug.c
@@ -10,15 +10,11 @@
  * published by the Free Software Foundation.
  */
 
-#include <linux/module.h>
 #include <linux/err.h>
-#include <linux/clk.h>
 #include <linux/io.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
-#include <linux/platform_device.h>
 #include <linux/debugfs.h>
-#include <linux/omap-iommu.h>
 #include <linux/platform_data/iommu-omap.h>
 
 #include "omap-iopgtable.h"
@@ -31,8 +27,7 @@ static struct dentry *iommu_debug_root;
 static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
 			       size_t count, loff_t *ppos)
 {
-	struct device *dev = file->private_data;
-	struct omap_iommu *obj = dev_to_omap_iommu(dev);
+	struct omap_iommu *obj = file->private_data;
 	char *p, *buf;
 	ssize_t bytes;
 
@@ -55,8 +50,7 @@ static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
 static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
 			      size_t count, loff_t *ppos)
 {
-	struct device *dev = file->private_data;
-	struct omap_iommu *obj = dev_to_omap_iommu(dev);
+	struct omap_iommu *obj = file->private_data;
 	char *p, *buf;
 	ssize_t bytes, rest;
 
@@ -141,8 +135,7 @@ out:
 static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
 				    size_t count, loff_t *ppos)
 {
-	struct device *dev = file->private_data;
-	struct omap_iommu *obj = dev_to_omap_iommu(dev);
+	struct omap_iommu *obj = file->private_data;
 	char *p, *buf;
 	size_t bytes;
 
@@ -181,93 +174,58 @@ DEBUG_FOPS_RO(pagetable);
 #define __DEBUG_ADD_FILE(attr, mode)					\
 	{								\
 		struct dentry *dent;					\
-		dent = debugfs_create_file(#attr, mode, parent,		\
-					   dev, &debug_##attr##_fops);	\
+		dent = debugfs_create_file(#attr, mode, obj->debug_dir,	\
+					   obj, &debug_##attr##_fops);	\
 		if (!dent)						\
-			return -ENOMEM;					\
+			goto err;					\
 	}
 
 #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
 
-static int iommu_debug_register(struct device *dev, void *data)
+void omap_iommu_debugfs_add(struct omap_iommu *obj)
 {
-	struct platform_device *pdev = to_platform_device(dev);
-	struct omap_iommu *obj = platform_get_drvdata(pdev);
-	struct omap_iommu_arch_data *arch_data;
-	struct dentry *d, *parent;
-
-	if (!obj || !obj->dev)
-		return -EINVAL;
-
-	arch_data = kzalloc(sizeof(*arch_data), GFP_KERNEL);
-	if (!arch_data)
-		return -ENOMEM;
-
-	arch_data->iommu_dev = obj;
+	struct dentry *d;
 
-	dev->archdata.iommu = arch_data;
+	if (!iommu_debug_root)
+		return;
 
-	d = debugfs_create_dir(obj->name, iommu_debug_root);
-	if (!d)
-		goto nomem;
-	parent = d;
+	obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
+	if (!obj->debug_dir)
+		return;
 
-	d = debugfs_create_u8("nr_tlb_entries", 0400, parent,
+	d = debugfs_create_u8("nr_tlb_entries", 0400, obj->debug_dir,
 			      (u8 *)&obj->nr_tlb_entries);
 	if (!d)
-		goto nomem;
+		return;
 
 	DEBUG_ADD_FILE_RO(regs);
 	DEBUG_ADD_FILE_RO(tlb);
 	DEBUG_ADD_FILE_RO(pagetable);
 
-	return 0;
+	return;
 
-nomem:
-	kfree(arch_data);
-	return -ENOMEM;
+err:
+	debugfs_remove_recursive(obj->debug_dir);
 }
 
-static int iommu_debug_unregister(struct device *dev, void *data)
+void omap_iommu_debugfs_remove(struct omap_iommu *obj)
 {
-	if (!dev->archdata.iommu)
-		return 0;
-
-	kfree(dev->archdata.iommu);
-
-	dev->archdata.iommu = NULL;
+	if (!obj->debug_dir)
+		return;
 
-	return 0;
+	debugfs_remove_recursive(obj->debug_dir);
 }
 
-static int __init iommu_debug_init(void)
+void __init omap_iommu_debugfs_init(void)
 {
-	struct dentry *d;
-	int err;
-
-	d = debugfs_create_dir("iommu", NULL);
-	if (!d)
-		return -ENOMEM;
-	iommu_debug_root = d;
-
-	err = omap_foreach_iommu_device(d, iommu_debug_register);
-	if (err)
-		goto err_out;
-	return 0;
-
-err_out:
-	debugfs_remove_recursive(iommu_debug_root);
-	return err;
+	if (debugfs_initialized()) {
+		iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
+		if (!iommu_debug_root)
+			pr_err("can't create debugfs dir\n");
+	}
 }
-module_init(iommu_debug_init)
 
-static void __exit iommu_debugfs_exit(void)
+void __exit omap_iommu_debugfs_exit(void)
 {
-	debugfs_remove_recursive(iommu_debug_root);
-	omap_foreach_iommu_device(NULL, iommu_debug_unregister);
+	debugfs_remove(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");
diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 9ace5557..717d654 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -472,8 +472,6 @@ static void flush_iotlb_all(struct omap_iommu *obj)
 	pm_runtime_put_sync(obj->dev);
 }
 
-#if defined(CONFIG_OMAP_IOMMU_DEBUG) || defined(CONFIG_OMAP_IOMMU_DEBUG_MODULE)
-
 #define pr_reg(name)							\
 	do {								\
 		ssize_t bytes;						\
@@ -602,8 +600,6 @@ int omap_foreach_iommu_device(void *data, int (*fn)(struct device *, void *))
 }
 EXPORT_SYMBOL_GPL(omap_foreach_iommu_device);
 
-#endif /* CONFIG_OMAP_IOMMU_DEBUG_MODULE */
-
 /*
  *	H/W pagetable operations
  */
@@ -1077,6 +1073,8 @@ static int omap_iommu_probe(struct platform_device *pdev)
 	pm_runtime_irq_safe(obj->dev);
 	pm_runtime_enable(obj->dev);
 
+	omap_iommu_debugfs_add(obj);
+
 	dev_info(&pdev->dev, "%s registered\n", obj->name);
 	return 0;
 }
@@ -1086,6 +1084,7 @@ static int omap_iommu_remove(struct platform_device *pdev)
 	struct omap_iommu *obj = platform_get_drvdata(pdev);
 
 	iopgtable_clear_entry_all(obj);
+	omap_iommu_debugfs_remove(obj);
 
 	pm_runtime_disable(obj->dev);
 
@@ -1403,6 +1402,8 @@ static int __init omap_iommu_init(void)
 
 	bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
 
+	omap_iommu_debugfs_init();
+
 	return platform_driver_register(&omap_iommu_driver);
 }
 /* must be ready before omap3isp is probed */
@@ -1413,6 +1414,8 @@ static void __exit omap_iommu_exit(void)
 	kmem_cache_destroy(iopte_cachep);
 
 	platform_driver_unregister(&omap_iommu_driver);
+
+	omap_iommu_debugfs_exit();
 }
 module_exit(omap_iommu_exit);
 
diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
index 0516e0e..6e9a8d2 100644
--- a/drivers/iommu/omap-iommu.h
+++ b/drivers/iommu/omap-iommu.h
@@ -30,6 +30,7 @@ struct omap_iommu {
 	void __iomem	*regbase;
 	struct device	*dev;
 	struct iommu_domain *domain;
+	struct dentry	*debug_dir;
 
 	spinlock_t	iommu_lock;	/* global for this whole object */
 
@@ -202,6 +203,12 @@ omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len);
 extern size_t
 omap_dump_tlb_entries(struct omap_iommu *obj, char *buf, ssize_t len);
 
+void omap_iommu_debugfs_init(void);
+void omap_iommu_debugfs_exit(void);
+
+void omap_iommu_debugfs_add(struct omap_iommu *obj);
+void omap_iommu_debugfs_remove(struct omap_iommu *obj);
+
 /*
  * register accessors
  */
-- 
2.1.0

Re: [PATCH 12/17] iommu/omap: Integrate omap-iommu-debug into omap-iommu

[Laurent Pinchart]

Hi Suman,

Thank you for the patch.

On Tuesday 30 September 2014 16:16:07 Suman Anna wrote:
> The debugfs support for OMAP IOMMU is currently implemented
> as a module, warranting certain OMAP-specific IOMMU API to
> be exported. The OMAP IOMMU, when enabled, can only be built-in
> into the kernel, so integrate the OMAP IOMMU debug module
> into the OMAP IOMMU driver. This helps in eliminating the
> need to export most of the current OMAP IOMMU API.
> 
> The following are the main changes:
> - The OMAP_IOMMU_DEBUG Kconfig option is eliminated, and
>   the OMAP IOMMU debugfs support is built alongside the OMAP
>   IOMMU driver, and enabled automatically only when debugfs
>   is enabled.

That's the part I'm unsure about. We're loosing the ability to save space by 
not building the omap-iommu debugfs support when debugfs is enabled.

For the rest of the series,

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> - The debugfs directory and entry creation logic is reversed,
>   the calls are invoked by the OMAP IOMMU driver now.
> - The current iffy circular logic of adding IOMMU archdata
>   to the IOMMU devices itself to get a pointer to the omap_iommu
>   object in the debugfs support code is replaced by directly
>   using the omap_iommu structure while creating the debugfs
>   entries.
> - The debugfs root directory is renamed from the generic name
>   "iommu" to a specific name "omap_iommu".
> - Unneeded headers have also been cleaned up while at this.
> - There will no longer be a omap-iommu-debug.ko module after
>   this patch.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> ---
>  drivers/iommu/Kconfig            |   9 ----
>  drivers/iommu/Makefile           |   3 +-
>  drivers/iommu/omap-iommu-debug.c | 102
> ++++++++++++--------------------------- drivers/iommu/omap-iommu.c       | 
> 11 +++--
>  drivers/iommu/omap-iommu.h       |   7 +++
>  5 files changed, 45 insertions(+), 87 deletions(-)
> 
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index dd51122..9724d4a 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -143,15 +143,6 @@ config OMAP_IOMMU
>  	depends on ARCH_OMAP2PLUS
>  	select IOMMU_API
> 
> -config OMAP_IOMMU_DEBUG
> -       tristate "Export OMAP IOMMU internals in DebugFS"
> -       depends on OMAP_IOMMU && DEBUG_FS
> -       help
> -         Select this to see extensive information about
> -         the internal state of OMAP IOMMU in debugfs.
> -
> -         Say N unless you know you need this.
> -
>  config TEGRA_IOMMU_GART
>  	bool "Tegra GART IOMMU Support"
>  	depends on ARCH_TEGRA_2x_SOC
> diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
> index 18fa446..e0a4fed 100644
> --- a/drivers/iommu/Makefile
> +++ b/drivers/iommu/Makefile
> @@ -10,8 +10,7 @@ obj-$(CONFIG_DMAR_TABLE) += dmar.o
>  obj-$(CONFIG_INTEL_IOMMU) += iova.o intel-iommu.o
>  obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
>  obj-$(CONFIG_IRQ_REMAP) += intel_irq_remapping.o irq_remapping.o
> -obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
> -obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o
> +obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o omap-iommu-debug.o
>  obj-$(CONFIG_TEGRA_IOMMU_GART) += tegra-gart.o
>  obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o
>  obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
> diff --git a/drivers/iommu/omap-iommu-debug.c
> b/drivers/iommu/omap-iommu-debug.c index 28de657..54a0dc6 100644
> --- a/drivers/iommu/omap-iommu-debug.c
> +++ b/drivers/iommu/omap-iommu-debug.c
> @@ -10,15 +10,11 @@
>   * published by the Free Software Foundation.
>   */
> 
> -#include <linux/module.h>
>  #include <linux/err.h>
> -#include <linux/clk.h>
>  #include <linux/io.h>
>  #include <linux/slab.h>
>  #include <linux/uaccess.h>
> -#include <linux/platform_device.h>
>  #include <linux/debugfs.h>
> -#include <linux/omap-iommu.h>
>  #include <linux/platform_data/iommu-omap.h>
> 
>  #include "omap-iopgtable.h"
> @@ -31,8 +27,7 @@ static struct dentry *iommu_debug_root;
>  static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
>  			       size_t count, loff_t *ppos)
>  {
> -	struct device *dev = file->private_data;
> -	struct omap_iommu *obj = dev_to_omap_iommu(dev);
> +	struct omap_iommu *obj = file->private_data;
>  	char *p, *buf;
>  	ssize_t bytes;
> 
> @@ -55,8 +50,7 @@ static ssize_t debug_read_regs(struct file *file, char
> __user *userbuf, static ssize_t debug_read_tlb(struct file *file, char
> __user *userbuf, size_t count, loff_t *ppos)
>  {
> -	struct device *dev = file->private_data;
> -	struct omap_iommu *obj = dev_to_omap_iommu(dev);
> +	struct omap_iommu *obj = file->private_data;
>  	char *p, *buf;
>  	ssize_t bytes, rest;
> 
> @@ -141,8 +135,7 @@ out:
>  static ssize_t debug_read_pagetable(struct file *file, char __user
> *userbuf, size_t count, loff_t *ppos)
>  {
> -	struct device *dev = file->private_data;
> -	struct omap_iommu *obj = dev_to_omap_iommu(dev);
> +	struct omap_iommu *obj = file->private_data;
>  	char *p, *buf;
>  	size_t bytes;
> 
> @@ -181,93 +174,58 @@ DEBUG_FOPS_RO(pagetable);
>  #define __DEBUG_ADD_FILE(attr, mode)					\
>  	{								\
>  		struct dentry *dent;					\
> -		dent = debugfs_create_file(#attr, mode, parent,		\
> -					   dev, &debug_##attr##_fops);	\
> +		dent = debugfs_create_file(#attr, mode, obj->debug_dir,	\
> +					   obj, &debug_##attr##_fops);	\
>  		if (!dent)						\
> -			return -ENOMEM;					\
> +			goto err;					\
>  	}
> 
>  #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
> 
> -static int iommu_debug_register(struct device *dev, void *data)
> +void omap_iommu_debugfs_add(struct omap_iommu *obj)
>  {
> -	struct platform_device *pdev = to_platform_device(dev);
> -	struct omap_iommu *obj = platform_get_drvdata(pdev);
> -	struct omap_iommu_arch_data *arch_data;
> -	struct dentry *d, *parent;
> -
> -	if (!obj || !obj->dev)
> -		return -EINVAL;
> -
> -	arch_data = kzalloc(sizeof(*arch_data), GFP_KERNEL);
> -	if (!arch_data)
> -		return -ENOMEM;
> -
> -	arch_data->iommu_dev = obj;
> +	struct dentry *d;
> 
> -	dev->archdata.iommu = arch_data;
> +	if (!iommu_debug_root)
> +		return;
> 
> -	d = debugfs_create_dir(obj->name, iommu_debug_root);
> -	if (!d)
> -		goto nomem;
> -	parent = d;
> +	obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
> +	if (!obj->debug_dir)
> +		return;
> 
> -	d = debugfs_create_u8("nr_tlb_entries", 0400, parent,
> +	d = debugfs_create_u8("nr_tlb_entries", 0400, obj->debug_dir,
>  			      (u8 *)&obj->nr_tlb_entries);
>  	if (!d)
> -		goto nomem;
> +		return;
> 
>  	DEBUG_ADD_FILE_RO(regs);
>  	DEBUG_ADD_FILE_RO(tlb);
>  	DEBUG_ADD_FILE_RO(pagetable);
> 
> -	return 0;
> +	return;
> 
> -nomem:
> -	kfree(arch_data);
> -	return -ENOMEM;
> +err:
> +	debugfs_remove_recursive(obj->debug_dir);
>  }
> 
> -static int iommu_debug_unregister(struct device *dev, void *data)
> +void omap_iommu_debugfs_remove(struct omap_iommu *obj)
>  {
> -	if (!dev->archdata.iommu)
> -		return 0;
> -
> -	kfree(dev->archdata.iommu);
> -
> -	dev->archdata.iommu = NULL;
> +	if (!obj->debug_dir)
> +		return;
> 
> -	return 0;
> +	debugfs_remove_recursive(obj->debug_dir);
>  }
> 
> -static int __init iommu_debug_init(void)
> +void __init omap_iommu_debugfs_init(void)
>  {
> -	struct dentry *d;
> -	int err;
> -
> -	d = debugfs_create_dir("iommu", NULL);
> -	if (!d)
> -		return -ENOMEM;
> -	iommu_debug_root = d;
> -
> -	err = omap_foreach_iommu_device(d, iommu_debug_register);
> -	if (err)
> -		goto err_out;
> -	return 0;
> -
> -err_out:
> -	debugfs_remove_recursive(iommu_debug_root);
> -	return err;
> +	if (debugfs_initialized()) {
> +		iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
> +		if (!iommu_debug_root)
> +			pr_err("can't create debugfs dir\n");
> +	}
>  }
> -module_init(iommu_debug_init)
> 
> -static void __exit iommu_debugfs_exit(void)
> +void __exit omap_iommu_debugfs_exit(void)
>  {
> -	debugfs_remove_recursive(iommu_debug_root);
> -	omap_foreach_iommu_device(NULL, iommu_debug_unregister);
> +	debugfs_remove(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");
> diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
> index 9ace5557..717d654 100644
> --- a/drivers/iommu/omap-iommu.c
> +++ b/drivers/iommu/omap-iommu.c
> @@ -472,8 +472,6 @@ static void flush_iotlb_all(struct omap_iommu *obj)
>  	pm_runtime_put_sync(obj->dev);
>  }
> 
> -#if defined(CONFIG_OMAP_IOMMU_DEBUG) ||
> defined(CONFIG_OMAP_IOMMU_DEBUG_MODULE) -
>  #define pr_reg(name)							\
>  	do {								\
>  		ssize_t bytes;						\
> @@ -602,8 +600,6 @@ int omap_foreach_iommu_device(void *data, int
> (*fn)(struct device *, void *)) }
>  EXPORT_SYMBOL_GPL(omap_foreach_iommu_device);
> 
> -#endif /* CONFIG_OMAP_IOMMU_DEBUG_MODULE */
> -
>  /*
>   *	H/W pagetable operations
>   */
> @@ -1077,6 +1073,8 @@ static int omap_iommu_probe(struct platform_device
> *pdev) pm_runtime_irq_safe(obj->dev);
>  	pm_runtime_enable(obj->dev);
> 
> +	omap_iommu_debugfs_add(obj);
> +
>  	dev_info(&pdev->dev, "%s registered\n", obj->name);
>  	return 0;
>  }
> @@ -1086,6 +1084,7 @@ static int omap_iommu_remove(struct platform_device
> *pdev) struct omap_iommu *obj = platform_get_drvdata(pdev);
> 
>  	iopgtable_clear_entry_all(obj);
> +	omap_iommu_debugfs_remove(obj);
> 
>  	pm_runtime_disable(obj->dev);
> 
> @@ -1403,6 +1402,8 @@ static int __init omap_iommu_init(void)
> 
>  	bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
> 
> +	omap_iommu_debugfs_init();
> +
>  	return platform_driver_register(&omap_iommu_driver);
>  }
>  /* must be ready before omap3isp is probed */
> @@ -1413,6 +1414,8 @@ static void __exit omap_iommu_exit(void)
>  	kmem_cache_destroy(iopte_cachep);
> 
>  	platform_driver_unregister(&omap_iommu_driver);
> +
> +	omap_iommu_debugfs_exit();
>  }
>  module_exit(omap_iommu_exit);
> 
> diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
> index 0516e0e..6e9a8d2 100644
> --- a/drivers/iommu/omap-iommu.h
> +++ b/drivers/iommu/omap-iommu.h
> @@ -30,6 +30,7 @@ struct omap_iommu {
>  	void __iomem	*regbase;
>  	struct device	*dev;
>  	struct iommu_domain *domain;
> +	struct dentry	*debug_dir;
> 
>  	spinlock_t	iommu_lock;	/* global for this whole object */
> 
> @@ -202,6 +203,12 @@ omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf,
> ssize_t len); extern size_t
>  omap_dump_tlb_entries(struct omap_iommu *obj, char *buf, ssize_t len);
> 
> +void omap_iommu_debugfs_init(void);
> +void omap_iommu_debugfs_exit(void);
> +
> +void omap_iommu_debugfs_add(struct omap_iommu *obj);
> +void omap_iommu_debugfs_remove(struct omap_iommu *obj);
> +
>  /*
>   * register accessors
>   */

-- 
Regards,

Laurent Pinchart

Re: [PATCH 12/17] iommu/omap: Integrate omap-iommu-debug into omap-iommu

[Suman Anna]

Hi Laurent,

> On Tuesday 30 September 2014 16:16:07 Suman Anna wrote:
>> The debugfs support for OMAP IOMMU is currently implemented
>> as a module, warranting certain OMAP-specific IOMMU API to
>> be exported. The OMAP IOMMU, when enabled, can only be built-in
>> into the kernel, so integrate the OMAP IOMMU debug module
>> into the OMAP IOMMU driver. This helps in eliminating the
>> need to export most of the current OMAP IOMMU API.
>>
>> The following are the main changes:
>> - The OMAP_IOMMU_DEBUG Kconfig option is eliminated, and
>>   the OMAP IOMMU debugfs support is built alongside the OMAP
>>   IOMMU driver, and enabled automatically only when debugfs
>>   is enabled.
> 
> That's the part I'm unsure about. We're loosing the ability to save space by 
> not building the omap-iommu debugfs support when debugfs is enabled.

Yeah, I thought about it a bit, and went in favor of eliminating the
Kconfig. I don't have a strong opinion on this, but if saving space is
what is preferred, I can easily rework this patch to add it back.

Joerg, any preference which way we should go here?

> 
> For the rest of the series,
> 
> Acked-by: Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>

Thank you for reviewing the patches.

regards
Suman

> 
>> - The debugfs directory and entry creation logic is reversed,
>>   the calls are invoked by the OMAP IOMMU driver now.
>> - The current iffy circular logic of adding IOMMU archdata
>>   to the IOMMU devices itself to get a pointer to the omap_iommu
>>   object in the debugfs support code is replaced by directly
>>   using the omap_iommu structure while creating the debugfs
>>   entries.
>> - The debugfs root directory is renamed from the generic name
>>   "iommu" to a specific name "omap_iommu".
>> - Unneeded headers have also been cleaned up while at this.
>> - There will no longer be a omap-iommu-debug.ko module after
>>   this patch.
>>
>> Signed-off-by: Suman Anna <s-anna-l0cyMroinI0@public.gmane.org>
>> ---
>>  drivers/iommu/Kconfig            |   9 ----
>>  drivers/iommu/Makefile           |   3 +-
>>  drivers/iommu/omap-iommu-debug.c | 102
>> ++++++++++++--------------------------- drivers/iommu/omap-iommu.c       | 
>> 11 +++--
>>  drivers/iommu/omap-iommu.h       |   7 +++
>>  5 files changed, 45 insertions(+), 87 deletions(-)
>>
>> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
>> index dd51122..9724d4a 100644
>> --- a/drivers/iommu/Kconfig
>> +++ b/drivers/iommu/Kconfig
>> @@ -143,15 +143,6 @@ config OMAP_IOMMU
>>  	depends on ARCH_OMAP2PLUS
>>  	select IOMMU_API
>>
>> -config OMAP_IOMMU_DEBUG
>> -       tristate "Export OMAP IOMMU internals in DebugFS"
>> -       depends on OMAP_IOMMU && DEBUG_FS
>> -       help
>> -         Select this to see extensive information about
>> -         the internal state of OMAP IOMMU in debugfs.
>> -
>> -         Say N unless you know you need this.
>> -
>>  config TEGRA_IOMMU_GART
>>  	bool "Tegra GART IOMMU Support"
>>  	depends on ARCH_TEGRA_2x_SOC
>> diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
>> index 18fa446..e0a4fed 100644
>> --- a/drivers/iommu/Makefile
>> +++ b/drivers/iommu/Makefile
>> @@ -10,8 +10,7 @@ obj-$(CONFIG_DMAR_TABLE) += dmar.o
>>  obj-$(CONFIG_INTEL_IOMMU) += iova.o intel-iommu.o
>>  obj-$(CONFIG_IPMMU_VMSA) += ipmmu-vmsa.o
>>  obj-$(CONFIG_IRQ_REMAP) += intel_irq_remapping.o irq_remapping.o
>> -obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o
>> -obj-$(CONFIG_OMAP_IOMMU_DEBUG) += omap-iommu-debug.o
>> +obj-$(CONFIG_OMAP_IOMMU) += omap-iommu.o omap-iommu-debug.o
>>  obj-$(CONFIG_TEGRA_IOMMU_GART) += tegra-gart.o
>>  obj-$(CONFIG_TEGRA_IOMMU_SMMU) += tegra-smmu.o
>>  obj-$(CONFIG_EXYNOS_IOMMU) += exynos-iommu.o
>> diff --git a/drivers/iommu/omap-iommu-debug.c
>> b/drivers/iommu/omap-iommu-debug.c index 28de657..54a0dc6 100644
>> --- a/drivers/iommu/omap-iommu-debug.c
>> +++ b/drivers/iommu/omap-iommu-debug.c
>> @@ -10,15 +10,11 @@
>>   * published by the Free Software Foundation.
>>   */
>>
>> -#include <linux/module.h>
>>  #include <linux/err.h>
>> -#include <linux/clk.h>
>>  #include <linux/io.h>
>>  #include <linux/slab.h>
>>  #include <linux/uaccess.h>
>> -#include <linux/platform_device.h>
>>  #include <linux/debugfs.h>
>> -#include <linux/omap-iommu.h>
>>  #include <linux/platform_data/iommu-omap.h>
>>
>>  #include "omap-iopgtable.h"
>> @@ -31,8 +27,7 @@ static struct dentry *iommu_debug_root;
>>  static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
>>  			       size_t count, loff_t *ppos)
>>  {
>> -	struct device *dev = file->private_data;
>> -	struct omap_iommu *obj = dev_to_omap_iommu(dev);
>> +	struct omap_iommu *obj = file->private_data;
>>  	char *p, *buf;
>>  	ssize_t bytes;
>>
>> @@ -55,8 +50,7 @@ static ssize_t debug_read_regs(struct file *file, char
>> __user *userbuf, static ssize_t debug_read_tlb(struct file *file, char
>> __user *userbuf, size_t count, loff_t *ppos)
>>  {
>> -	struct device *dev = file->private_data;
>> -	struct omap_iommu *obj = dev_to_omap_iommu(dev);
>> +	struct omap_iommu *obj = file->private_data;
>>  	char *p, *buf;
>>  	ssize_t bytes, rest;
>>
>> @@ -141,8 +135,7 @@ out:
>>  static ssize_t debug_read_pagetable(struct file *file, char __user
>> *userbuf, size_t count, loff_t *ppos)
>>  {
>> -	struct device *dev = file->private_data;
>> -	struct omap_iommu *obj = dev_to_omap_iommu(dev);
>> +	struct omap_iommu *obj = file->private_data;
>>  	char *p, *buf;
>>  	size_t bytes;
>>
>> @@ -181,93 +174,58 @@ DEBUG_FOPS_RO(pagetable);
>>  #define __DEBUG_ADD_FILE(attr, mode)					\
>>  	{								\
>>  		struct dentry *dent;					\
>> -		dent = debugfs_create_file(#attr, mode, parent,		\
>> -					   dev, &debug_##attr##_fops);	\
>> +		dent = debugfs_create_file(#attr, mode, obj->debug_dir,	\
>> +					   obj, &debug_##attr##_fops);	\
>>  		if (!dent)						\
>> -			return -ENOMEM;					\
>> +			goto err;					\
>>  	}
>>
>>  #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400)
>>
>> -static int iommu_debug_register(struct device *dev, void *data)
>> +void omap_iommu_debugfs_add(struct omap_iommu *obj)
>>  {
>> -	struct platform_device *pdev = to_platform_device(dev);
>> -	struct omap_iommu *obj = platform_get_drvdata(pdev);
>> -	struct omap_iommu_arch_data *arch_data;
>> -	struct dentry *d, *parent;
>> -
>> -	if (!obj || !obj->dev)
>> -		return -EINVAL;
>> -
>> -	arch_data = kzalloc(sizeof(*arch_data), GFP_KERNEL);
>> -	if (!arch_data)
>> -		return -ENOMEM;
>> -
>> -	arch_data->iommu_dev = obj;
>> +	struct dentry *d;
>>
>> -	dev->archdata.iommu = arch_data;
>> +	if (!iommu_debug_root)
>> +		return;
>>
>> -	d = debugfs_create_dir(obj->name, iommu_debug_root);
>> -	if (!d)
>> -		goto nomem;
>> -	parent = d;
>> +	obj->debug_dir = debugfs_create_dir(obj->name, iommu_debug_root);
>> +	if (!obj->debug_dir)
>> +		return;
>>
>> -	d = debugfs_create_u8("nr_tlb_entries", 0400, parent,
>> +	d = debugfs_create_u8("nr_tlb_entries", 0400, obj->debug_dir,
>>  			      (u8 *)&obj->nr_tlb_entries);
>>  	if (!d)
>> -		goto nomem;
>> +		return;
>>
>>  	DEBUG_ADD_FILE_RO(regs);
>>  	DEBUG_ADD_FILE_RO(tlb);
>>  	DEBUG_ADD_FILE_RO(pagetable);
>>
>> -	return 0;
>> +	return;
>>
>> -nomem:
>> -	kfree(arch_data);
>> -	return -ENOMEM;
>> +err:
>> +	debugfs_remove_recursive(obj->debug_dir);
>>  }
>>
>> -static int iommu_debug_unregister(struct device *dev, void *data)
>> +void omap_iommu_debugfs_remove(struct omap_iommu *obj)
>>  {
>> -	if (!dev->archdata.iommu)
>> -		return 0;
>> -
>> -	kfree(dev->archdata.iommu);
>> -
>> -	dev->archdata.iommu = NULL;
>> +	if (!obj->debug_dir)
>> +		return;
>>
>> -	return 0;
>> +	debugfs_remove_recursive(obj->debug_dir);
>>  }
>>
>> -static int __init iommu_debug_init(void)
>> +void __init omap_iommu_debugfs_init(void)
>>  {
>> -	struct dentry *d;
>> -	int err;
>> -
>> -	d = debugfs_create_dir("iommu", NULL);
>> -	if (!d)
>> -		return -ENOMEM;
>> -	iommu_debug_root = d;
>> -
>> -	err = omap_foreach_iommu_device(d, iommu_debug_register);
>> -	if (err)
>> -		goto err_out;
>> -	return 0;
>> -
>> -err_out:
>> -	debugfs_remove_recursive(iommu_debug_root);
>> -	return err;
>> +	if (debugfs_initialized()) {
>> +		iommu_debug_root = debugfs_create_dir("omap_iommu", NULL);
>> +		if (!iommu_debug_root)
>> +			pr_err("can't create debugfs dir\n");
>> +	}
>>  }
>> -module_init(iommu_debug_init)
>>
>> -static void __exit iommu_debugfs_exit(void)
>> +void __exit omap_iommu_debugfs_exit(void)
>>  {
>> -	debugfs_remove_recursive(iommu_debug_root);
>> -	omap_foreach_iommu_device(NULL, iommu_debug_unregister);
>> +	debugfs_remove(iommu_debug_root);
>>  }
>> -module_exit(iommu_debugfs_exit)
>> -
>> -MODULE_DESCRIPTION("omap iommu: debugfs interface");
>> -MODULE_AUTHOR("Hiroshi DOYU <Hiroshi.DOYU-xNZwKgViW5gAvxtiuMwx3w@public.gmane.org>");
>> -MODULE_LICENSE("GPL v2");
>> diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
>> index 9ace5557..717d654 100644
>> --- a/drivers/iommu/omap-iommu.c
>> +++ b/drivers/iommu/omap-iommu.c
>> @@ -472,8 +472,6 @@ static void flush_iotlb_all(struct omap_iommu *obj)
>>  	pm_runtime_put_sync(obj->dev);
>>  }
>>
>> -#if defined(CONFIG_OMAP_IOMMU_DEBUG) ||
>> defined(CONFIG_OMAP_IOMMU_DEBUG_MODULE) -
>>  #define pr_reg(name)							\
>>  	do {								\
>>  		ssize_t bytes;						\
>> @@ -602,8 +600,6 @@ int omap_foreach_iommu_device(void *data, int
>> (*fn)(struct device *, void *)) }
>>  EXPORT_SYMBOL_GPL(omap_foreach_iommu_device);
>>
>> -#endif /* CONFIG_OMAP_IOMMU_DEBUG_MODULE */
>> -
>>  /*
>>   *	H/W pagetable operations
>>   */
>> @@ -1077,6 +1073,8 @@ static int omap_iommu_probe(struct platform_device
>> *pdev) pm_runtime_irq_safe(obj->dev);
>>  	pm_runtime_enable(obj->dev);
>>
>> +	omap_iommu_debugfs_add(obj);
>> +
>>  	dev_info(&pdev->dev, "%s registered\n", obj->name);
>>  	return 0;
>>  }
>> @@ -1086,6 +1084,7 @@ static int omap_iommu_remove(struct platform_device
>> *pdev) struct omap_iommu *obj = platform_get_drvdata(pdev);
>>
>>  	iopgtable_clear_entry_all(obj);
>> +	omap_iommu_debugfs_remove(obj);
>>
>>  	pm_runtime_disable(obj->dev);
>>
>> @@ -1403,6 +1402,8 @@ static int __init omap_iommu_init(void)
>>
>>  	bus_set_iommu(&platform_bus_type, &omap_iommu_ops);
>>
>> +	omap_iommu_debugfs_init();
>> +
>>  	return platform_driver_register(&omap_iommu_driver);
>>  }
>>  /* must be ready before omap3isp is probed */
>> @@ -1413,6 +1414,8 @@ static void __exit omap_iommu_exit(void)
>>  	kmem_cache_destroy(iopte_cachep);
>>
>>  	platform_driver_unregister(&omap_iommu_driver);
>> +
>> +	omap_iommu_debugfs_exit();
>>  }
>>  module_exit(omap_iommu_exit);
>>
>> diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
>> index 0516e0e..6e9a8d2 100644
>> --- a/drivers/iommu/omap-iommu.h
>> +++ b/drivers/iommu/omap-iommu.h
>> @@ -30,6 +30,7 @@ struct omap_iommu {
>>  	void __iomem	*regbase;
>>  	struct device	*dev;
>>  	struct iommu_domain *domain;
>> +	struct dentry	*debug_dir;
>>
>>  	spinlock_t	iommu_lock;	/* global for this whole object */
>>
>> @@ -202,6 +203,12 @@ omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf,
>> ssize_t len); extern size_t
>>  omap_dump_tlb_entries(struct omap_iommu *obj, char *buf, ssize_t len);
>>
>> +void omap_iommu_debugfs_init(void);
>> +void omap_iommu_debugfs_exit(void);
>> +
>> +void omap_iommu_debugfs_add(struct omap_iommu *obj);
>> +void omap_iommu_debugfs_remove(struct omap_iommu *obj);
>> +
>>  /*
>>   * register accessors
>>   */
> 

Re: [PATCH 12/17] iommu/omap: Integrate omap-iommu-debug into omap-iommu

[Suman Anna]

Hi Joerg,

On 10/01/2014 11:07 AM, Anna, Suman wrote:
> Hi Laurent,
> 
>> On Tuesday 30 September 2014 16:16:07 Suman Anna wrote:
>>> The debugfs support for OMAP IOMMU is currently implemented
>>> as a module, warranting certain OMAP-specific IOMMU API to
>>> be exported. The OMAP IOMMU, when enabled, can only be built-in
>>> into the kernel, so integrate the OMAP IOMMU debug module
>>> into the OMAP IOMMU driver. This helps in eliminating the
>>> need to export most of the current OMAP IOMMU API.
>>>
>>> The following are the main changes:
>>> - The OMAP_IOMMU_DEBUG Kconfig option is eliminated, and
>>>   the OMAP IOMMU debugfs support is built alongside the OMAP
>>>   IOMMU driver, and enabled automatically only when debugfs
>>>   is enabled.
>>
>> That's the part I'm unsure about. We're loosing the ability to save space by 
>> not building the omap-iommu debugfs support when debugfs is enabled.
> 
> Yeah, I thought about it a bit, and went in favor of eliminating the
> Kconfig. I don't have a strong opinion on this, but if saving space is
> what is preferred, I can easily rework this patch to add it back.
> 
> Joerg, any preference which way we should go here?

I am looking to refresh this series for 3.19, and this is the only patch
that may need some changes. Please let me know what your preference is,
and I can rework this patch if needed. Either way,
the plan is to not have an OMAP IOMMU debugfs module, but only to
have an option not to build the debugfs portions.

regards
Suman

> 
>>
>> For the rest of the series,
>>
>> Acked-by: Laurent Pinchart <laurent.pinchart-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
> 
> Thank you for reviewing the patches.
> 
> regards
> Suman
> 

Re: [PATCH 12/17] iommu/omap: Integrate omap-iommu-debug into omap-iommu

[Joerg Roedel]

On Tue, Oct 21, 2014 at 04:28:27PM -0500, Suman Anna wrote:
> I am looking to refresh this series for 3.19, and this is the only patch
> that may need some changes. Please let me know what your preference is,
> and I can rework this patch if needed. Either way,
> the plan is to not have an OMAP IOMMU debugfs module, but only to
> have an option not to build the debugfs portions.

Can I apply this series without this patch and you send me an updated
version of only this patch? If yes, please let me know, otherwise please
rebase the series on v3.18-rc1 and resend.

Thanks,

	Joerg

Re: [PATCH 12/17] iommu/omap: Integrate omap-iommu-debug into omap-iommu

[Suman Anna]

Hi Joerg,

On 10/22/2014 08:29 AM, Joerg Roedel wrote:
> On Tue, Oct 21, 2014 at 04:28:27PM -0500, Suman Anna wrote:
>> I am looking to refresh this series for 3.19, and this is the only patch
>> that may need some changes. Please let me know what your preference is,
>> and I can rework this patch if needed. Either way,
>> the plan is to not have an OMAP IOMMU debugfs module, but only to
>> have an option not to build the debugfs portions.
> 
> Can I apply this series without this patch and you send me an updated
> version of only this patch? If yes, please let me know, otherwise please
> rebase the series on v3.18-rc1 and resend.

Some of the patches following this patch don't apply without this patch,
so this patch alone cannot be dropped. The preceding patches (Patches 1
through 11) are not affected though. I will rebase and resend the entire
series.

regards
Suman

[PATCH 13/17] iommu/omap: Remove couple of unused exported functions

[Suman Anna]

The exported functions omap_foreach_iommu_device() and
omap_iotlb_cr_to_e() have been deleted, as they are no
longer needed.

The function omap_foreach_iommu_device() is not required
after the consolidation of the OMAP IOMMU debug module,
and the function omap_iotlb_cr_to_e() is not required
after making the debugfs entry 'pagetable' read-only.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/omap-iommu.c | 21 ---------------------
 drivers/iommu/omap-iommu.h |  5 -----
 2 files changed, 26 deletions(-)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index 717d654..b3bc087 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -203,20 +203,6 @@ static void iommu_disable(struct omap_iommu *obj)
 /*
  *	TLB operations
  */
-void omap_iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
-{
-	BUG_ON(!cr || !e);
-
-	e->da		= cr->cam & MMU_CAM_VATAG_MASK;
-	e->pa		= cr->ram & MMU_RAM_PADDR_MASK;
-	e->valid	= cr->cam & MMU_CAM_V;
-	e->pgsz		= cr->cam & MMU_CAM_PGSZ_MASK;
-	e->endian	= cr->ram & MMU_RAM_ENDIAN_MASK;
-	e->elsz		= cr->ram & MMU_RAM_ELSZ_MASK;
-	e->mixed	= cr->ram & MMU_RAM_MIXED;
-}
-EXPORT_SYMBOL_GPL(omap_iotlb_cr_to_e);
-
 static inline int iotlb_cr_valid(struct cr_regs *cr)
 {
 	if (!cr)
@@ -593,13 +579,6 @@ size_t omap_dump_tlb_entries(struct omap_iommu *obj, char *buf, ssize_t bytes)
 }
 EXPORT_SYMBOL_GPL(omap_dump_tlb_entries);
 
-int omap_foreach_iommu_device(void *data, int (*fn)(struct device *, void *))
-{
-	return driver_for_each_device(&omap_iommu_driver.driver,
-				      NULL, data, fn);
-}
-EXPORT_SYMBOL_GPL(omap_foreach_iommu_device);
-
 /*
  *	H/W pagetable operations
  */
diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
index 6e9a8d2..2659139 100644
--- a/drivers/iommu/omap-iommu.h
+++ b/drivers/iommu/omap-iommu.h
@@ -190,14 +190,9 @@ static inline struct omap_iommu *dev_to_omap_iommu(struct device *dev)
 /*
  * global functions
  */
-extern void omap_iotlb_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e);
-
 extern int
 omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e);
 
-extern int omap_foreach_iommu_device(void *data,
-				int (*fn)(struct device *, void *));
-
 extern ssize_t
 omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len);
 extern size_t
-- 
2.1.0

[PATCH 14/17] iommu/omap: Do not export unneeded functions

[Suman Anna]

The following functions were exported previously for usage by
the OMAP IOMMU debug module:
	omap_iommu_dump_ctx()
	omap_dump_tlb_entries()
	omap_iopgtable_store_entry()

These functions need not be exported anymore as the OMAP IOMMU
debugfs code is integrated with the OMAP IOMMU driver, and
there won't be external users for these functions. So, remove
the EXPORT_SYMBOL_GPL on these. The omap_iopgtable_store_entry()
is also made internal only, after making the 'pagetable' debugfs
entry read-only.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/omap-iommu.c | 6 ++----
 drivers/iommu/omap-iommu.h | 3 ---
 2 files changed, 2 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/omap-iommu.c b/drivers/iommu/omap-iommu.c
index b3bc087..a140873 100644
--- a/drivers/iommu/omap-iommu.c
+++ b/drivers/iommu/omap-iommu.c
@@ -509,7 +509,6 @@ ssize_t omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t bytes)
 
 	return bytes;
 }
-EXPORT_SYMBOL_GPL(omap_iommu_dump_ctx);
 
 static int
 __dump_tlb_entries(struct omap_iommu *obj, struct cr_regs *crs, int num)
@@ -577,7 +576,6 @@ size_t omap_dump_tlb_entries(struct omap_iommu *obj, char *buf, ssize_t bytes)
 
 	return p - buf;
 }
-EXPORT_SYMBOL_GPL(omap_dump_tlb_entries);
 
 /*
  *	H/W pagetable operations
@@ -760,7 +758,8 @@ iopgtable_store_entry_core(struct omap_iommu *obj, struct iotlb_entry *e)
  * @obj:	target iommu
  * @e:		an iommu tlb entry info
  **/
-int omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e)
+static int
+omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e)
 {
 	int err;
 
@@ -770,7 +769,6 @@ int omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e)
 		prefetch_iotlb_entry(obj, e);
 	return err;
 }
-EXPORT_SYMBOL_GPL(omap_iopgtable_store_entry);
 
 /**
  * iopgtable_lookup_entry - Lookup an iommu pte entry
diff --git a/drivers/iommu/omap-iommu.h b/drivers/iommu/omap-iommu.h
index 2659139..f32ddc3 100644
--- a/drivers/iommu/omap-iommu.h
+++ b/drivers/iommu/omap-iommu.h
@@ -190,9 +190,6 @@ static inline struct omap_iommu *dev_to_omap_iommu(struct device *dev)
 /*
  * global functions
  */
-extern int
-omap_iopgtable_store_entry(struct omap_iommu *obj, struct iotlb_entry *e);
-
 extern ssize_t
 omap_iommu_dump_ctx(struct omap_iommu *obj, char *buf, ssize_t len);
 extern size_t
-- 
2.1.0

[PATCH 16/17] iommu/omap: Fix bus error on debugfs access of unattached IOMMU

[Suman Anna]

Any debugfs access on an OMAP IOMMU that is not enabled (done during
attach) results in a bus error due to access of registers without
the clock or the reset enabled for the respective IOMMU. So, add a
check to make sure the IOMMU is enabled/attached by a client device.
This gracefully prints a "Operation not permitted" trace when the
corresponding IOMMU is not enabled.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/omap-iommu-debug.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c
index 54a0dc6..e7b8aca 100644
--- a/drivers/iommu/omap-iommu-debug.c
+++ b/drivers/iommu/omap-iommu-debug.c
@@ -24,6 +24,11 @@ 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;
+}
+
 static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
 			       size_t count, loff_t *ppos)
 {
@@ -31,6 +36,9 @@ static ssize_t debug_read_regs(struct file *file, char __user *userbuf,
 	char *p, *buf;
 	ssize_t bytes;
 
+	if (is_omap_iommu_detached(obj))
+		return -EPERM;
+
 	buf = kmalloc(count, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
@@ -54,6 +62,9 @@ static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
 	char *p, *buf;
 	ssize_t bytes, rest;
 
+	if (is_omap_iommu_detached(obj))
+		return -EPERM;
+
 	buf = kmalloc(count, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
@@ -139,6 +150,9 @@ static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
 	char *p, *buf;
 	size_t bytes;
 
+	if (is_omap_iommu_detached(obj))
+		return -EPERM;
+
 	buf = (char *)__get_free_page(GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
-- 
2.1.0

[PATCH 17/17] iommu/omap: Switch pagetable debugfs entry to use seq_file

[Suman Anna]

The debugfs entry 'pagetable' that shows the page table entry
(PTE) data currently outputs only data that can be fit into a
page. Switch the entry to use the seq_file interface so that
it can show all the valid page table entries.

The patch also corrected the output for L2 entries, and prints
the proper L2 PTE instead of the previous L1 page descriptor
pointer.

Signed-off-by: Suman Anna <s-anna@ti.com>
---
 drivers/iommu/omap-iommu-debug.c | 81 ++++++++++++++--------------------------
 1 file changed, 28 insertions(+), 53 deletions(-)

diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c
index e7b8aca..096947c5 100644
--- a/drivers/iommu/omap-iommu-debug.c
+++ b/drivers/iommu/omap-iommu-debug.c
@@ -85,95 +85,70 @@ static ssize_t debug_read_tlb(struct file *file, char __user *userbuf,
 	return bytes;
 }
 
-#define dump_ioptable_entry_one(lv, da, val)			\
-	({							\
-		int __err = 0;					\
-		ssize_t bytes;					\
-		const int maxcol = 22;				\
-		const char *str = "%d: %08x %08x\n";		\
-		bytes = snprintf(p, maxcol, str, lv, da, val);	\
-		p += bytes;					\
-		len -= bytes;					\
-		if (len < maxcol)				\
-			__err = -ENOMEM;			\
-		__err;						\
-	})
-
-static ssize_t dump_ioptable(struct omap_iommu *obj, char *buf, ssize_t len)
+static void dump_ioptable(struct seq_file *s)
 {
-	int i;
-	u32 *iopgd;
-	char *p = buf;
+	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++) {
-		int j, err;
-		u32 *iopte;
-		u32 da;
-
 		if (!*iopgd)
 			continue;
 
 		if (!(*iopgd & IOPGD_TABLE)) {
 			da = i << IOPGD_SHIFT;
-
-			err = dump_ioptable_entry_one(1, da, *iopgd);
-			if (err)
-				goto out;
+			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);
-			err = dump_ioptable_entry_one(2, da, *iopgd);
-			if (err)
-				goto out;
+			seq_printf(s, "2: 0x%08x 0x%08x\n", da, *iopte);
 		}
 	}
-out:
-	spin_unlock(&obj->page_table_lock);
 
-	return p - buf;
+	spin_unlock(&obj->page_table_lock);
 }
 
-static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
-				    size_t count, loff_t *ppos)
+static int debug_read_pagetable(struct seq_file *s, void *data)
 {
-	struct omap_iommu *obj = file->private_data;
-	char *p, *buf;
-	size_t bytes;
+	struct omap_iommu *obj = s->private;
 
 	if (is_omap_iommu_detached(obj))
 		return -EPERM;
 
-	buf = (char *)__get_free_page(GFP_KERNEL);
-	if (!buf)
-		return -ENOMEM;
-	p = buf;
-
-	p += sprintf(p, "L: %8s %8s\n", "da:", "pa:");
-	p += sprintf(p, "-----------------------------------------\n");
-
 	mutex_lock(&iommu_debug_lock);
 
-	bytes = PAGE_SIZE - (p - buf);
-	p += dump_ioptable(obj, p, bytes);
-
-	bytes = simple_read_from_buffer(userbuf, count, ppos, buf, p - buf);
+	seq_printf(s, "L: %8s %8s\n", "da:", "pte:");
+	seq_puts(s, "--------------------------\n");
+	dump_ioptable(s);
 
 	mutex_unlock(&iommu_debug_lock);
-	free_page((unsigned long)buf);
 
-	return bytes;
+	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,					\
@@ -183,7 +158,7 @@ static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf,
 
 DEBUG_FOPS_RO(regs);
 DEBUG_FOPS_RO(tlb);
-DEBUG_FOPS_RO(pagetable);
+DEBUG_SEQ_FOPS_RO(pagetable);
 
 #define __DEBUG_ADD_FILE(attr, mode)					\
 	{								\
-- 
2.1.0