Commit 12b1fdb4 authored by Kevin Hilman's avatar Kevin Hilman Committed by Paul Walmsley
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OMAP: hwmod: separate list locking and hwmod hardware locking 



Currently omap_hwmod_mutex is being used to protect both the list
access/modification and concurrent access to hwmod functions.  This
patch separates these two types of locking.

First, omap_hwmod_mutex is used only to protect access and
modification of omap_hwmod_list.  Also cleaned up some comments
referring to this mutex that are no longer needed.

Then, for protecting concurrent access to hwmod functions, use a
per-hwmod mutex.  This protects concurrent access to a single hwmod,
but would allow concurrent access to different hwmods.

Signed-off-by: default avatarKevin Hilman <khilman@deeprootsystems.com>
[paul@pwsan.com: added structure documentation; changed mutex variable
 name]
Signed-off-by: default avatarPaul Walmsley <paul@pwsan.com>
parent ff4d3e18

arch/arm/mach-omap2/omap_hwmod.c

+30 −32
Original line number Diff line number Diff line
@@ -767,10 +767,10 @@ static struct omap_hwmod *_lookup(const char *name) 
 * @data: not used; pass NULL

 *

 * Called by omap_hwmod_late_init() (after omap2_clk_init()).

 * Resolves all clock names embedded in the hwmod.  Must be called

 * with omap_hwmod_mutex held.  Returns -EINVAL if the omap_hwmod

 * has not yet been registered or if the clocks have already been

 * initialized, 0 on success, or a non-zero error on failure.

 * Resolves all clock names embedded in the hwmod.  Returns -EINVAL if

 * the omap_hwmod has not yet been registered or if the clocks have

 * already been initialized, 0 on success, or a non-zero error on

 * failure.

 */

static int _init_clocks(struct omap_hwmod *oh, void *data)

{
@@ -838,10 +838,9 @@ static int _wait_target_ready(struct omap_hwmod *oh) 
 * @oh: struct omap_hwmod *

 *

 * Resets an omap_hwmod @oh via the OCP_SYSCONFIG bit.  hwmod must be

 * enabled for this to work.  Must be called with omap_hwmod_mutex

 * held.  Returns -EINVAL if the hwmod cannot be reset this way or if

 * the hwmod is in the wrong state, -ETIMEDOUT if the module did not

 * reset in time, or 0 upon success.

 * enabled for this to work.  Returns -EINVAL if the hwmod cannot be

 * reset this way or if the hwmod is in the wrong state, -ETIMEDOUT if

 * the module did not reset in time, or 0 upon success.

 */

static int _reset(struct omap_hwmod *oh)

{
@@ -891,9 +890,8 @@ static int _reset(struct omap_hwmod *oh) 
 * @oh: struct omap_hwmod *

 *

 * Enables an omap_hwmod @oh such that the MPU can access the hwmod's

 * register target.  Must be called with omap_hwmod_mutex held.

 * Returns -EINVAL if the hwmod is in the wrong state or passes along

 * the return value of _wait_target_ready().

 * register target.  Returns -EINVAL if the hwmod is in the wrong

 * state or passes along the return value of _wait_target_ready().

 */

int _omap_hwmod_enable(struct omap_hwmod *oh)

{
@@ -1004,11 +1002,10 @@ static int _shutdown(struct omap_hwmod *oh) 
 * @skip_setup_idle_p: do not idle hwmods at the end of the fn if 1

 *

 * Writes the CLOCKACTIVITY bits @clockact to the hwmod @oh

 * OCP_SYSCONFIG register.  Must be called with omap_hwmod_mutex held.

 * @skip_setup_idle is intended to be used on a system that will not

 * call omap_hwmod_enable() to enable devices (e.g., a system without

 * PM runtime).  Returns -EINVAL if the hwmod is in the wrong state or

 * returns 0.

 * OCP_SYSCONFIG register.  @skip_setup_idle is intended to be used on

 * a system that will not call omap_hwmod_enable() to enable devices

 * (e.g., a system without PM runtime).  Returns -EINVAL if the hwmod

 * is in the wrong state or returns 0.

 */

static int _setup(struct omap_hwmod *oh, void *data)

{
@@ -1038,6 +1035,7 @@ static int _setup(struct omap_hwmod *oh, void *data) 
		}

	}



	mutex_init(&oh->_mutex);

	oh->_state = _HWMOD_STATE_INITIALIZED;



	r = _omap_hwmod_enable(oh);
@@ -1323,9 +1321,9 @@ int omap_hwmod_enable(struct omap_hwmod *oh) 
	if (!oh)

		return -EINVAL;



	mutex_lock(&omap_hwmod_mutex);

	mutex_lock(&oh->_mutex);

	r = _omap_hwmod_enable(oh);

	mutex_unlock(&omap_hwmod_mutex);

	mutex_unlock(&oh->_mutex);



	return r;

}
@@ -1343,9 +1341,9 @@ int omap_hwmod_idle(struct omap_hwmod *oh) 
	if (!oh)

		return -EINVAL;



	mutex_lock(&omap_hwmod_mutex);

	mutex_lock(&oh->_mutex);

	_omap_hwmod_idle(oh);

	mutex_unlock(&omap_hwmod_mutex);

	mutex_unlock(&oh->_mutex);



	return 0;

}
@@ -1363,9 +1361,9 @@ int omap_hwmod_shutdown(struct omap_hwmod *oh) 
	if (!oh)

		return -EINVAL;



	mutex_lock(&omap_hwmod_mutex);

	mutex_lock(&oh->_mutex);

	_shutdown(oh);

	mutex_unlock(&omap_hwmod_mutex);

	mutex_unlock(&oh->_mutex);



	return 0;

}
@@ -1378,9 +1376,9 @@ int omap_hwmod_shutdown(struct omap_hwmod *oh) 
 */

int omap_hwmod_enable_clocks(struct omap_hwmod *oh)

{

	mutex_lock(&omap_hwmod_mutex);

	mutex_lock(&oh->_mutex);

	_enable_clocks(oh);

	mutex_unlock(&omap_hwmod_mutex);

	mutex_unlock(&oh->_mutex);



	return 0;

}
@@ -1393,9 +1391,9 @@ int omap_hwmod_enable_clocks(struct omap_hwmod *oh) 
 */

int omap_hwmod_disable_clocks(struct omap_hwmod *oh)

{

	mutex_lock(&omap_hwmod_mutex);

	mutex_lock(&oh->_mutex);

	_disable_clocks(oh);

	mutex_unlock(&omap_hwmod_mutex);

	mutex_unlock(&oh->_mutex);



	return 0;

}
@@ -1443,9 +1441,9 @@ int omap_hwmod_reset(struct omap_hwmod *oh) 
	if (!oh)

		return -EINVAL;



	mutex_lock(&omap_hwmod_mutex);

	mutex_lock(&oh->_mutex);

	r = _reset(oh);

	mutex_unlock(&omap_hwmod_mutex);

	mutex_unlock(&oh->_mutex);



	return r;

}
@@ -1646,9 +1644,9 @@ int omap_hwmod_enable_wakeup(struct omap_hwmod *oh) 
	    !(oh->class->sysc->sysc_flags & SYSC_HAS_ENAWAKEUP))

		return -EINVAL;



	mutex_lock(&omap_hwmod_mutex);

	mutex_lock(&oh->_mutex);

	_enable_wakeup(oh);

	mutex_unlock(&omap_hwmod_mutex);

	mutex_unlock(&oh->_mutex);



	return 0;

}
@@ -1671,9 +1669,9 @@ int omap_hwmod_disable_wakeup(struct omap_hwmod *oh) 
	    !(oh->class->sysc->sysc_flags & SYSC_HAS_ENAWAKEUP))

		return -EINVAL;



	mutex_lock(&omap_hwmod_mutex);

	mutex_lock(&oh->_mutex);

	_disable_wakeup(oh);

	mutex_unlock(&omap_hwmod_mutex);

	mutex_unlock(&oh->_mutex);



	return 0;

}

arch/arm/plat-omap/include/plat/omap_hwmod.h

+3 −0
Original line number Diff line number Diff line
@@ -35,6 +35,7 @@ 
#include <linux/kernel.h>

#include <linux/list.h>

#include <linux/ioport.h>

#include <linux/mutex.h>

#include <plat/cpu.h>



struct omap_device;
@@ -433,6 +434,7 @@ struct omap_hwmod_class { 
 * @_state: internal-use hwmod state

 * @flags: hwmod flags (documented below)

 * @omap_chip: OMAP chips this hwmod is present on

 * @_mutex: mutex serializing operations on this hwmod

 * @node: list node for hwmod list (internal use)

 *

 * @main_clk refers to this module's "main clock," which for our
@@ -461,6 +463,7 @@ struct omap_hwmod { 
	void				*dev_attr;

	u32				_sysc_cache;

	void __iomem			*_mpu_rt_va;

	struct mutex			_mutex;

	struct list_head		node;

	u16				flags;

	u8				_mpu_port_index;

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