Commit 3f8ddb03 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/hwspinlock 

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/hwspinlock:
  hwspinlock: add MAINTAINERS entries
  hwspinlock/omap: omap_hwspinlock_remove should be __devexit
  hwspinlock/u8500: add hwspinlock driver
  hwspinlock/core: register a bank of hwspinlocks in a single API call
  hwspinlock/core: remove stubs for register/unregister
  hwspinlock/core: use a mutex to protect the radix tree
  hwspinlock/core/omap: fix id issues on multiple hwspinlock devices
  hwspinlock/omap: simplify allocation scheme
  hwspinlock/core: simplify 'owner' handling
  hwspinlock/core: simplify Kconfig

Fix up trivial conflicts (addition of omap_hwspinlock_pdata, removal of
omap_spinlock_latency) in arch/arm/mach-omap2/hwspinlock.c

Also, do an "evil merge" to fix a compile error in omap_hsmmc.c which
for some reason was reported in the same email thread as the "please
pull hwspinlock changes".
parents 30307c69 8b37fcfc

Documentation/hwspinlock.txt

+44 −30
Original line number Diff line number Diff line
@@ -39,23 +39,20 @@ independent, drivers. 
     in case an unused hwspinlock isn't available. Users of this

     API will usually want to communicate the lock's id to the remote core

     before it can be used to achieve synchronization.

     Can be called from an atomic context (this function will not sleep) but

     not from within interrupt context.

     Should be called from a process context (might sleep).



  struct hwspinlock *hwspin_lock_request_specific(unsigned int id);

   - assign a specific hwspinlock id and return its address, or NULL

     if that hwspinlock is already in use. Usually board code will

     be calling this function in order to reserve specific hwspinlock

     ids for predefined purposes.

     Can be called from an atomic context (this function will not sleep) but

     not from within interrupt context.

     Should be called from a process context (might sleep).



  int hwspin_lock_free(struct hwspinlock *hwlock);

   - free a previously-assigned hwspinlock; returns 0 on success, or an

     appropriate error code on failure (e.g. -EINVAL if the hwspinlock

     is already free).

     Can be called from an atomic context (this function will not sleep) but

     not from within interrupt context.

     Should be called from a process context (might sleep).



  int hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int timeout);

   - lock a previously-assigned hwspinlock with a timeout limit (specified in
@@ -230,45 +227,62 @@ int hwspinlock_example2(void) 


4. API for implementors



  int hwspin_lock_register(struct hwspinlock *hwlock);

  int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,

		const struct hwspinlock_ops *ops, int base_id, int num_locks);

   - to be called from the underlying platform-specific implementation, in

     order to register a new hwspinlock instance. Can be called from an atomic

     context (this function will not sleep) but not from within interrupt

     context. Returns 0 on success, or appropriate error code on failure.

     order to register a new hwspinlock device (which is usually a bank of

     numerous locks). Should be called from a process context (this function

     might sleep).

     Returns 0 on success, or appropriate error code on failure.



  struct hwspinlock *hwspin_lock_unregister(unsigned int id);

  int hwspin_lock_unregister(struct hwspinlock_device *bank);

   - to be called from the underlying vendor-specific implementation, in order

     to unregister an existing (and unused) hwspinlock instance.

     Can be called from an atomic context (will not sleep) but not from

     within interrupt context.

     to unregister an hwspinlock device (which is usually a bank of numerous

     locks).

     Should be called from a process context (this function might sleep).

     Returns the address of hwspinlock on success, or NULL on error (e.g.

     if the hwspinlock is sill in use).



5. struct hwspinlock

5. Important structs



This struct represents an hwspinlock instance. It is registered by the

underlying hwspinlock implementation using the hwspin_lock_register() API.

struct hwspinlock_device is a device which usually contains a bank

of hardware locks. It is registered by the underlying hwspinlock

implementation using the hwspin_lock_register() API.



/**

 * struct hwspinlock - vendor-specific hwspinlock implementation

 *

 * @dev: underlying device, will be used with runtime PM api

 * @ops: vendor-specific hwspinlock handlers

 * @id: a global, unique, system-wide, index of the lock.

 * @lock: initialized and used by hwspinlock core

 * @owner: underlying implementation module, used to maintain module ref count

 * struct hwspinlock_device - a device which usually spans numerous hwspinlocks

 * @dev: underlying device, will be used to invoke runtime PM api

 * @ops: platform-specific hwspinlock handlers

 * @base_id: id index of the first lock in this device

 * @num_locks: number of locks in this device

 * @lock: dynamically allocated array of 'struct hwspinlock'

 */

struct hwspinlock {

struct hwspinlock_device {

	struct device *dev;

	const struct hwspinlock_ops *ops;

	int id;

	int base_id;

	int num_locks;

	struct hwspinlock lock[0];

};



struct hwspinlock_device contains an array of hwspinlock structs, each

of which represents a single hardware lock:



/**

 * struct hwspinlock - this struct represents a single hwspinlock instance

 * @bank: the hwspinlock_device structure which owns this lock

 * @lock: initialized and used by hwspinlock core

 * @priv: private data, owned by the underlying platform-specific hwspinlock drv

 */

struct hwspinlock {

	struct hwspinlock_device *bank;

	spinlock_t lock;

	struct module *owner;

	void *priv;

};



The underlying implementation is responsible to assign the dev, ops, id and

owner members. The lock member, OTOH, is initialized and used by the hwspinlock

core.

When registering a bank of locks, the hwspinlock driver only needs to

set the priv members of the locks. The rest of the members are set and

initialized by the hwspinlock core itself.



6. Implementation callbacks

MAINTAINERS

+14 −0
Original line number Diff line number Diff line
@@ -3018,6 +3018,13 @@ F: Documentation/hw_random.txt 
F:	drivers/char/hw_random/

F:	include/linux/hw_random.h



HARDWARE SPINLOCK CORE

M:	Ohad Ben-Cohen <ohad@wizery.com>

S:	Maintained

F:	Documentation/hwspinlock.txt

F:	drivers/hwspinlock/hwspinlock_*

F:	include/linux/hwspinlock.h



HARMONY SOUND DRIVER

M:	Kyle McMartin <kyle@mcmartin.ca>

L:	linux-parisc@vger.kernel.org
@@ -4714,6 +4721,13 @@ S: Maintained 
F:	drivers/video/omap2/

F:	Documentation/arm/OMAP/DSS



OMAP HARDWARE SPINLOCK SUPPORT

M:	Ohad Ben-Cohen <ohad@wizery.com>

L:	linux-omap@vger.kernel.org

S:	Maintained

F:	drivers/hwspinlock/omap_hwspinlock.c

F:	arch/arm/mach-omap2/hwspinlock.c



OMAP MMC SUPPORT

M:	Jarkko Lavinen <jarkko.lavinen@nokia.com>

L:	linux-omap@vger.kernel.org

arch/arm/mach-omap2/hwspinlock.c

+8 −1
Original line number Diff line number Diff line
@@ -19,10 +19,15 @@ 
#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/err.h>

#include <linux/hwspinlock.h>



#include <plat/omap_hwmod.h>

#include <plat/omap_device.h>



static struct hwspinlock_pdata omap_hwspinlock_pdata __initdata = {

	.base_id = 0,

};



int __init hwspinlocks_init(void)

{

	int retval = 0;
@@ -40,7 +45,9 @@ int __init hwspinlocks_init(void) 
	if (oh == NULL)

		return -EINVAL;



	pdev = omap_device_build(dev_name, 0, oh, NULL, 0, NULL, 0, false);

	pdev = omap_device_build(dev_name, 0, oh, &omap_hwspinlock_pdata,

				sizeof(struct hwspinlock_pdata),

				NULL, 0, false);

	if (IS_ERR(pdev)) {

		pr_err("Can't build omap_device for %s:%s\n", dev_name,

								oh_name);

drivers/hwspinlock/Kconfig

+18 −9
Original line number Diff line number Diff line
@@ -2,22 +2,31 @@ 
# Generic HWSPINLOCK framework

#



# HWSPINLOCK always gets selected by whoever wants it.

config HWSPINLOCK

	tristate "Generic Hardware Spinlock framework"

	depends on ARCH_OMAP4

	help

	  Say y here to support the generic hardware spinlock framework.

	  You only need to enable this if you have hardware spinlock module

	  on your system (usually only relevant if your system has remote slave

	  coprocessors).

	tristate



	  If unsure, say N.

menu "Hardware Spinlock drivers"



config HWSPINLOCK_OMAP

	tristate "OMAP Hardware Spinlock device"

	depends on HWSPINLOCK && ARCH_OMAP4

	depends on ARCH_OMAP4

	select HWSPINLOCK

	help

	  Say y here to support the OMAP Hardware Spinlock device (firstly

	  introduced in OMAP4).



	  If unsure, say N.



config HSEM_U8500

	tristate "STE Hardware Semaphore functionality"

	depends on ARCH_U8500

	select HWSPINLOCK

	help

	  Say y here to support the STE Hardware Semaphore functionality, which

	  provides a synchronisation mechanism for the various processor on the

	  SoC.



	  If unsure, say N.



endmenu

drivers/hwspinlock/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -4,3 +4,4 @@ 


obj-$(CONFIG_HWSPINLOCK)		+= hwspinlock_core.o

obj-$(CONFIG_HWSPINLOCK_OMAP)		+= omap_hwspinlock.o

obj-$(CONFIG_HSEM_U8500)		+= u8500_hsem.o

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