From 315d8f5ccdbb2abb609d1ca1119fb32273a09cf8 Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Sun, 4 Sep 2011 23:19:51 +0300 Subject: [PATCH 01/10] hwspinlock/core: simplify Kconfig Simplify hwspinlock's Kconfig by making the global CONFIG_HWSPINLOCK entry invisible; users will just select it when needed. This also prepares the ground for adding hwspinlock support for other platforms (the 'depends on ARCH_OMAP4' was rather hideous, and while we're at it, a dedicated menu is added). Signed-off-by: Ohad Ben-Cohen --- drivers/hwspinlock/Kconfig | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig index 1f29bab6b3e5..c8e7bdac1404 100644 --- a/drivers/hwspinlock/Kconfig +++ b/drivers/hwspinlock/Kconfig @@ -2,22 +2,20 @@ # 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. + +endmenu From e467b6421435f467e274d4f25d62900e1e0e4286 Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Mon, 5 Sep 2011 16:42:36 +0300 Subject: [PATCH 02/10] hwspinlock/core: simplify 'owner' handling Use struct device_driver's owner member instead of asking drivers to explicitly pass the owner again. This simplifies drivers and also save some memory, since there's no point now in maintaining a separate owner pointer per hwspinlock. Signed-off-by: Ohad Ben-Cohen --- Documentation/hwspinlock.txt | 6 ++---- drivers/hwspinlock/hwspinlock_core.c | 4 ++-- drivers/hwspinlock/hwspinlock_internal.h | 4 +--- drivers/hwspinlock/omap_hwspinlock.c | 2 +- 4 files changed, 6 insertions(+), 10 deletions(-) diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt index 7dcd1a4e726c..bbaa4649b637 100644 --- a/Documentation/hwspinlock.txt +++ b/Documentation/hwspinlock.txt @@ -256,18 +256,16 @@ underlying hwspinlock implementation using the hwspin_lock_register() 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 { struct device *dev; const struct hwspinlock_ops *ops; int id; spinlock_t lock; - struct module *owner; }; -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 +The underlying implementation is responsible to assign the dev, ops and id +members. The lock member, OTOH, is initialized and used by the hwspinlock core. 6. Implementation callbacks diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 43a62714b4fb..af5175c5d5f4 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -352,7 +352,7 @@ static int __hwspin_lock_request(struct hwspinlock *hwlock) int ret; /* prevent underlying implementation from being removed */ - if (!try_module_get(hwlock->owner)) { + if (!try_module_get(hwlock->dev->driver->owner)) { dev_err(hwlock->dev, "%s: can't get owner\n", __func__); return -EINVAL; } @@ -535,7 +535,7 @@ int hwspin_lock_free(struct hwspinlock *hwlock) /* sanity check (this shouldn't happen) */ WARN_ON(tmp != hwlock); - module_put(hwlock->owner); + module_put(hwlock->dev->driver->owner); out: spin_unlock(&hwspinlock_tree_lock); diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h index 69935e6b93e5..fb25830c2ee7 100644 --- a/drivers/hwspinlock/hwspinlock_internal.h +++ b/drivers/hwspinlock/hwspinlock_internal.h @@ -44,10 +44,9 @@ struct hwspinlock_ops { * @ops: platform-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 * * Note: currently simplicity was opted for, but later we can squeeze some - * memory bytes by grouping the dev, ops and owner members in a single + * memory bytes by grouping dev, ops in a single * per-platform struct, and have all hwspinlocks point at it. */ struct hwspinlock { @@ -55,7 +54,6 @@ struct hwspinlock { const struct hwspinlock_ops *ops; int id; spinlock_t lock; - struct module *owner; }; #endif /* __HWSPINLOCK_HWSPINLOCK_H */ diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c index a8f02734c026..1d19fe9324a4 100644 --- a/drivers/hwspinlock/omap_hwspinlock.c +++ b/drivers/hwspinlock/omap_hwspinlock.c @@ -143,7 +143,6 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) } omap_lock->lock.dev = &pdev->dev; - omap_lock->lock.owner = THIS_MODULE; omap_lock->lock.id = i; omap_lock->lock.ops = &omap_hwspinlock_ops; omap_lock->addr = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i; @@ -208,6 +207,7 @@ static struct platform_driver omap_hwspinlock_driver = { .remove = omap_hwspinlock_remove, .driver = { .name = "omap_hwspinlock", + .owner = THIS_MODULE, }, }; From c97f6dd0fe21dfd658c59c144a1b7fd5d8db04ac Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Mon, 5 Sep 2011 17:30:34 +0300 Subject: [PATCH 03/10] hwspinlock/omap: simplify allocation scheme Instead of allocating every hwspinlock separately, allocate them all in one shot. This both simplifies the driver and helps achieving better slab utilization. Reported-by: Arnd Bergmann Signed-off-by: Ohad Ben-Cohen --- drivers/hwspinlock/omap_hwspinlock.c | 51 ++++++++++------------------ 1 file changed, 17 insertions(+), 34 deletions(-) diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c index 1d19fe9324a4..d0583480fe33 100644 --- a/drivers/hwspinlock/omap_hwspinlock.c +++ b/drivers/hwspinlock/omap_hwspinlock.c @@ -52,6 +52,7 @@ struct omap_hwspinlock { struct omap_hwspinlock_state { int num_locks; /* Total number of locks in system */ void __iomem *io_base; /* Mapped base address */ + struct omap_hwspinlock lock[0]; /* Array of 'num_locks' locks */ }; static int omap_hwspinlock_trylock(struct hwspinlock *lock) @@ -95,7 +96,6 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) { struct omap_hwspinlock *omap_lock; struct omap_hwspinlock_state *state; - struct hwspinlock *lock; struct resource *res; void __iomem *io_base; int i, ret; @@ -104,15 +104,9 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) if (!res) return -ENODEV; - state = kzalloc(sizeof(*state), GFP_KERNEL); - if (!state) - return -ENOMEM; - io_base = ioremap(res->start, resource_size(res)); - if (!io_base) { - ret = -ENOMEM; - goto free_state; - } + if (!io_base) + return -ENOMEM; /* Determine number of locks */ i = readl(io_base + SYSSTATUS_OFFSET); @@ -124,7 +118,15 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) goto iounmap_base; } - state->num_locks = i * 32; + i *= 32; /* actual number of locks in this device */ + + state = kzalloc(sizeof(*state) + i * sizeof(*omap_lock), GFP_KERNEL); + if (!state) { + ret = -ENOMEM; + goto iounmap_base; + } + + state->num_locks = i; state->io_base = io_base; platform_set_drvdata(pdev, state); @@ -136,11 +138,7 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) pm_runtime_enable(&pdev->dev); for (i = 0; i < state->num_locks; i++) { - omap_lock = kzalloc(sizeof(*omap_lock), GFP_KERNEL); - if (!omap_lock) { - ret = -ENOMEM; - goto free_locks; - } + omap_lock = &state->lock[i]; omap_lock->lock.dev = &pdev->dev; omap_lock->lock.id = i; @@ -148,30 +146,19 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) omap_lock->addr = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i; ret = hwspin_lock_register(&omap_lock->lock); - if (ret) { - kfree(omap_lock); + if (ret) goto free_locks; - } } return 0; free_locks: - while (--i >= 0) { - lock = hwspin_lock_unregister(i); - /* this should't happen, but let's give our best effort */ - if (!lock) { - dev_err(&pdev->dev, "%s: cleanups failed\n", __func__); - continue; - } - omap_lock = to_omap_hwspinlock(lock); - kfree(omap_lock); - } + while (--i >= 0) + hwspin_lock_unregister(i); pm_runtime_disable(&pdev->dev); + kfree(state); iounmap_base: iounmap(io_base); -free_state: - kfree(state); return ret; } @@ -179,7 +166,6 @@ static int omap_hwspinlock_remove(struct platform_device *pdev) { struct omap_hwspinlock_state *state = platform_get_drvdata(pdev); struct hwspinlock *lock; - struct omap_hwspinlock *omap_lock; int i; for (i = 0; i < state->num_locks; i++) { @@ -190,9 +176,6 @@ static int omap_hwspinlock_remove(struct platform_device *pdev) dev_err(&pdev->dev, "%s: failed on %d\n", __func__, i); return -EBUSY; } - - omap_lock = to_omap_hwspinlock(lock); - kfree(omap_lock); } pm_runtime_disable(&pdev->dev); From c3c1250e93a7ab1327a9fc49d2a22405672f4204 Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Mon, 5 Sep 2011 23:15:06 +0300 Subject: [PATCH 04/10] hwspinlock/core/omap: fix id issues on multiple hwspinlock devices hwspinlock devices provide system-wide hardware locks that are used by remote processors that have no other way to achieve synchronization. To achieve that, each physical lock must have a system-wide id number that is agreed upon, otherwise remote processors can't possibly assume they're using the same hardware lock. Usually boards have a single hwspinlock device, which provides several hwspinlocks, and in this case, they can be trivially numbered 0 to (num-of-locks - 1). In case boards have several hwspinlocks devices, a different base id should be used for each hwspinlock device (they can't all use 0 as a starting id!). While this is certainly not common, it's just plain wrong to just silently use 0 as a base id whenever the hwspinlock driver is probed. This patch provides a hwspinlock_pdata structure, that boards can use to set a different base id for each of the hwspinlock devices they may have, and demonstrates how to use it with the omap hwspinlock driver. While we're at it, make sure the hwspinlock core prints an explicit error message in case an hwspinlock is registered with an id number that already exists; this will help users catch such base id issues. Reported-by: Arnd Bergmann Signed-off-by: Ohad Ben-Cohen Acked-by: Tony Lindgren --- arch/arm/mach-omap2/hwspinlock.c | 8 +++++++- drivers/hwspinlock/hwspinlock_core.c | 2 ++ drivers/hwspinlock/omap_hwspinlock.c | 6 +++++- include/linux/hwspinlock.h | 28 ++++++++++++++++++++++++++++ 4 files changed, 42 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-omap2/hwspinlock.c b/arch/arm/mach-omap2/hwspinlock.c index 06d4a80660a5..eb7e509957db 100644 --- a/arch/arm/mach-omap2/hwspinlock.c +++ b/arch/arm/mach-omap2/hwspinlock.c @@ -19,10 +19,15 @@ #include #include #include +#include #include #include +static struct hwspinlock_pdata omap_hwspinlock_pdata __initdata = { + .base_id = 0, +}; + struct omap_device_pm_latency omap_spinlock_latency[] = { { .deactivate_func = omap_device_idle_hwmods, @@ -48,7 +53,8 @@ int __init hwspinlocks_init(void) if (oh == NULL) return -EINVAL; - od = omap_device_build(dev_name, 0, oh, NULL, 0, + od = omap_device_build(dev_name, 0, oh, &omap_hwspinlock_pdata, + sizeof(struct hwspinlock_pdata), omap_spinlock_latency, ARRAY_SIZE(omap_spinlock_latency), false); if (IS_ERR(od)) { diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index af5175c5d5f4..4eb85b4a320e 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -282,6 +282,8 @@ int hwspin_lock_register(struct hwspinlock *hwlock) spin_lock(&hwspinlock_tree_lock); ret = radix_tree_insert(&hwspinlock_tree, hwlock->id, hwlock); + if (ret == -EEXIST) + pr_err("hwspinlock id %d already exists!\n", hwlock->id); if (ret) goto out; diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c index d0583480fe33..2044d181e49d 100644 --- a/drivers/hwspinlock/omap_hwspinlock.c +++ b/drivers/hwspinlock/omap_hwspinlock.c @@ -94,12 +94,16 @@ static const struct hwspinlock_ops omap_hwspinlock_ops = { static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) { + struct hwspinlock_pdata *pdata = pdev->dev.platform_data; struct omap_hwspinlock *omap_lock; struct omap_hwspinlock_state *state; struct resource *res; void __iomem *io_base; int i, ret; + if (!pdata) + return -ENODEV; + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); if (!res) return -ENODEV; @@ -141,7 +145,7 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) omap_lock = &state->lock[i]; omap_lock->lock.dev = &pdev->dev; - omap_lock->lock.id = i; + omap_lock->lock.id = pdata->base_id + i; omap_lock->lock.ops = &omap_hwspinlock_ops; omap_lock->addr = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i; diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h index 8390efc457eb..f85cef5452f2 100644 --- a/include/linux/hwspinlock.h +++ b/include/linux/hwspinlock.h @@ -27,6 +27,34 @@ struct hwspinlock; +/** + * struct hwspinlock_pdata - platform data for hwspinlock drivers + * @base_id: base id for this hwspinlock device + * + * hwspinlock devices provide system-wide hardware locks that are used + * by remote processors that have no other way to achieve synchronization. + * + * To achieve that, each physical lock must have a system-wide id number + * that is agreed upon, otherwise remote processors can't possibly assume + * they're using the same hardware lock. + * + * Usually boards have a single hwspinlock device, which provides several + * hwspinlocks, and in this case, they can be trivially numbered 0 to + * (num-of-locks - 1). + * + * In case boards have several hwspinlocks devices, a different base id + * should be used for each hwspinlock device (they can't all use 0 as + * a starting id!). + * + * This platform data structure should be used to provide the base id + * for each device (which is trivially 0 when only a single hwspinlock + * device exists). It can be shared between different platforms, hence + * its location. + */ +struct hwspinlock_pdata { + int base_id; +}; + #if defined(CONFIG_HWSPINLOCK) || defined(CONFIG_HWSPINLOCK_MODULE) int hwspin_lock_register(struct hwspinlock *lock); From 93b465c2e186d96fb90012ba0f9372eb9952e732 Mon Sep 17 00:00:00 2001 From: Juan Gutierrez Date: Tue, 6 Sep 2011 09:30:16 +0300 Subject: [PATCH 05/10] hwspinlock/core: use a mutex to protect the radix tree Since we're using non-atomic radix tree allocations, we should be protecting the tree using a mutex and not a spinlock. Non-atomic allocations and process context locking is good enough, as the tree is manipulated only when locks are registered/ unregistered/requested/freed. The locks themselves are still protected by spinlocks of course, and mutexes are not involved in the locking/unlocking paths. Cc: Signed-off-by: Juan Gutierrez [ohad@wizery.com: rewrite the commit log, #include mutex.h, add minor commentary] [ohad@wizery.com: update register/unregister parts in hwspinlock.txt] Signed-off-by: Ohad Ben-Cohen --- Documentation/hwspinlock.txt | 18 +++++------ drivers/hwspinlock/hwspinlock_core.c | 45 +++++++++++++--------------- 2 files changed, 27 insertions(+), 36 deletions(-) diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt index bbaa4649b637..9171f9120143 100644 --- a/Documentation/hwspinlock.txt +++ b/Documentation/hwspinlock.txt @@ -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 @@ -232,15 +229,14 @@ int hwspinlock_example2(void) int hwspin_lock_register(struct hwspinlock *hwlock); - 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 instance. 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); - 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. + 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). diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 4eb85b4a320e..0d20b82df0a7 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -26,6 +26,7 @@ #include #include #include +#include #include "hwspinlock_internal.h" @@ -52,10 +53,12 @@ static RADIX_TREE(hwspinlock_tree, GFP_KERNEL); /* - * Synchronization of access to the tree is achieved using this spinlock, + * Synchronization of access to the tree is achieved using this mutex, * as the radix-tree API requires that users provide all synchronisation. + * A mutex is needed because we're using non-atomic radix tree allocations. */ -static DEFINE_SPINLOCK(hwspinlock_tree_lock); +static DEFINE_MUTEX(hwspinlock_tree_lock); + /** * __hwspin_trylock() - attempt to lock a specific hwspinlock @@ -261,8 +264,7 @@ EXPORT_SYMBOL_GPL(__hwspin_unlock); * This function should be called from the underlying platform-specific * implementation, to register a new hwspinlock instance. * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context. + * Should be called from a process context (might sleep) * * Returns 0 on success, or an appropriate error code on failure */ @@ -279,7 +281,7 @@ int hwspin_lock_register(struct hwspinlock *hwlock) spin_lock_init(&hwlock->lock); - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); ret = radix_tree_insert(&hwspinlock_tree, hwlock->id, hwlock); if (ret == -EEXIST) @@ -295,7 +297,7 @@ int hwspin_lock_register(struct hwspinlock *hwlock) WARN_ON(tmp != hwlock); out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return ret; } EXPORT_SYMBOL_GPL(hwspin_lock_register); @@ -307,8 +309,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_register); * This function should be called from the underlying platform-specific * implementation, to unregister an existing (and unused) hwspinlock. * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context. + * Should be called from a process context (might sleep) * * Returns the address of hwspinlock @id on success, or NULL on failure */ @@ -317,7 +318,7 @@ struct hwspinlock *hwspin_lock_unregister(unsigned int id) struct hwspinlock *hwlock = NULL; int ret; - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); /* make sure the hwspinlock is not in use (tag is set) */ ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); @@ -333,7 +334,7 @@ struct hwspinlock *hwspin_lock_unregister(unsigned int id) } out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return hwlock; } EXPORT_SYMBOL_GPL(hwspin_lock_unregister); @@ -402,9 +403,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_get_id); * to the remote core before it can be used for synchronization (to get the * id of a given hwlock, use hwspin_lock_get_id()). * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context (simply because there is no use case for - * that yet). + * Should be called from a process context (might sleep) * * Returns the address of the assigned hwspinlock, or NULL on error */ @@ -413,7 +412,7 @@ struct hwspinlock *hwspin_lock_request(void) struct hwspinlock *hwlock; int ret; - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); /* look for an unused lock */ ret = radix_tree_gang_lookup_tag(&hwspinlock_tree, (void **)&hwlock, @@ -433,7 +432,7 @@ struct hwspinlock *hwspin_lock_request(void) hwlock = NULL; out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return hwlock; } EXPORT_SYMBOL_GPL(hwspin_lock_request); @@ -447,9 +446,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_request); * Usually early board code will be calling this function in order to * reserve specific hwspinlock ids for predefined purposes. * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context (simply because there is no use case for - * that yet). + * Should be called from a process context (might sleep) * * Returns the address of the assigned hwspinlock, or NULL on error */ @@ -458,7 +455,7 @@ struct hwspinlock *hwspin_lock_request_specific(unsigned int id) struct hwspinlock *hwlock; int ret; - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); /* make sure this hwspinlock exists */ hwlock = radix_tree_lookup(&hwspinlock_tree, id); @@ -484,7 +481,7 @@ struct hwspinlock *hwspin_lock_request_specific(unsigned int id) hwlock = NULL; out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return hwlock; } EXPORT_SYMBOL_GPL(hwspin_lock_request_specific); @@ -497,9 +494,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_request_specific); * Should only be called with an @hwlock that was retrieved from * an earlier call to omap_hwspin_lock_request{_specific}. * - * Can be called from an atomic context (will not sleep) but not from - * within interrupt context (simply because there is no use case for - * that yet). + * Should be called from a process context (might sleep) * * Returns 0 on success, or an appropriate error code on failure */ @@ -513,7 +508,7 @@ int hwspin_lock_free(struct hwspinlock *hwlock) return -EINVAL; } - spin_lock(&hwspinlock_tree_lock); + mutex_lock(&hwspinlock_tree_lock); /* make sure the hwspinlock is used */ ret = radix_tree_tag_get(&hwspinlock_tree, hwlock->id, @@ -540,7 +535,7 @@ int hwspin_lock_free(struct hwspinlock *hwlock) module_put(hwlock->dev->driver->owner); out: - spin_unlock(&hwspinlock_tree_lock); + mutex_unlock(&hwspinlock_tree_lock); return ret; } EXPORT_SYMBOL_GPL(hwspin_lock_free); From c536abfdf5227987b8a72ff955b64e62fd58fe91 Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Thu, 8 Sep 2011 21:16:17 +0300 Subject: [PATCH 06/10] hwspinlock/core: remove stubs for register/unregister hwspinlock drivers must anyway select CONFIG_HWSPINLOCK, so there's no point in having register/unregister stubs. Removing those stubs will only make it easier for developers to catch CONFIG_HWSPINLOCK mis-.config-urations. Signed-off-by: Ohad Ben-Cohen --- include/linux/hwspinlock.h | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h index f85cef5452f2..c246522a9551 100644 --- a/include/linux/hwspinlock.h +++ b/include/linux/hwspinlock.h @@ -122,16 +122,6 @@ static inline int hwspin_lock_get_id(struct hwspinlock *hwlock) return 0; } -static inline int hwspin_lock_register(struct hwspinlock *hwlock) -{ - return -ENODEV; -} - -static inline struct hwspinlock *hwspin_lock_unregister(unsigned int id) -{ - return NULL; -} - #endif /* !CONFIG_HWSPINLOCK */ /** From 300bab9770e2bd10262bcc78e7249fdce2c74b38 Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Tue, 6 Sep 2011 15:39:21 +0300 Subject: [PATCH 07/10] hwspinlock/core: register a bank of hwspinlocks in a single API call Hardware Spinlock devices usually contain numerous locks (known devices today support between 32 to 256 locks). Originally hwspinlock core required drivers to register (and later, when needed, unregister) each lock separately. That worked, but required hwspinlocks drivers to do a bit extra work when they were probed/removed. This patch changes hwspin_lock_{un}register() to allow a bank of hwspinlocks to be {un}registered in a single invocation. A new 'struct hwspinlock_device', which contains an array of 'struct hwspinlock's is now being passed to the core upon registration (so instead of wrapping each struct hwspinlock, a priv member has been added to allow drivers to piggyback their private data with each hwspinlock). While at it, several per-lock members were moved to be per-device: 1. struct device *dev 2. struct hwspinlock_ops *ops In addition, now that the array of locks is handled by the core, there's no reason to maintain a per-lock 'int id' member: the id of the lock anyway equals to its index in the bank's array plus the bank's base_id. Remove this per-lock id member too, and instead use a simple pointers arithmetic to derive it. As a result of this change, hwspinlocks drivers are now simpler and smaller (about %20 code reduction) and the memory footprint of the hwspinlock framework is reduced. Signed-off-by: Ohad Ben-Cohen --- Documentation/hwspinlock.txt | 60 ++++++--- drivers/hwspinlock/hwspinlock_core.c | 165 +++++++++++++++-------- drivers/hwspinlock/hwspinlock_internal.h | 40 ++++-- drivers/hwspinlock/omap_hwspinlock.c | 84 ++++-------- include/linux/hwspinlock.h | 8 +- 5 files changed, 212 insertions(+), 145 deletions(-) diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt index 9171f9120143..a903ee5e9776 100644 --- a/Documentation/hwspinlock.txt +++ b/Documentation/hwspinlock.txt @@ -227,42 +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. Should be called from - a process context (this function might sleep). + 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. + 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 + * 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; - spinlock_t lock; + int base_id; + int num_locks; + struct hwspinlock lock[0]; }; -The underlying implementation is responsible to assign the dev, ops and id -members. The lock member, OTOH, is initialized and used by the hwspinlock -core. +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; + void *priv; +}; + +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 diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 0d20b82df0a7..61c9cf15fa52 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -117,7 +117,7 @@ int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags) return -EBUSY; /* try to take the hwspinlock device */ - ret = hwlock->ops->trylock(hwlock); + ret = hwlock->bank->ops->trylock(hwlock); /* if hwlock is already taken, undo spin_trylock_* and exit */ if (!ret) { @@ -199,8 +199,8 @@ int __hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int to, * Allow platform-specific relax handlers to prevent * hogging the interconnect (no sleeping, though) */ - if (hwlock->ops->relax) - hwlock->ops->relax(hwlock); + if (hwlock->bank->ops->relax) + hwlock->bank->ops->relax(hwlock); } return ret; @@ -245,7 +245,7 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) */ mb(); - hwlock->ops->unlock(hwlock); + hwlock->bank->ops->unlock(hwlock); /* Undo the spin_trylock{_irq, _irqsave} called while locking */ if (mode == HWLOCK_IRQSTATE) @@ -257,63 +257,32 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) } EXPORT_SYMBOL_GPL(__hwspin_unlock); -/** - * hwspin_lock_register() - register a new hw spinlock - * @hwlock: hwspinlock to register. - * - * This function should be called from the underlying platform-specific - * implementation, to register a new hwspinlock instance. - * - * Should be called from a process context (might sleep) - * - * Returns 0 on success, or an appropriate error code on failure - */ -int hwspin_lock_register(struct hwspinlock *hwlock) +static int hwspin_lock_register_single(struct hwspinlock *hwlock, int id) { struct hwspinlock *tmp; int ret; - if (!hwlock || !hwlock->ops || - !hwlock->ops->trylock || !hwlock->ops->unlock) { - pr_err("invalid parameters\n"); - return -EINVAL; - } - - spin_lock_init(&hwlock->lock); - mutex_lock(&hwspinlock_tree_lock); - ret = radix_tree_insert(&hwspinlock_tree, hwlock->id, hwlock); - if (ret == -EEXIST) - pr_err("hwspinlock id %d already exists!\n", hwlock->id); - if (ret) + ret = radix_tree_insert(&hwspinlock_tree, id, hwlock); + if (ret) { + if (ret == -EEXIST) + pr_err("hwspinlock id %d already exists!\n", id); goto out; + } /* mark this hwspinlock as available */ - tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock->id, - HWSPINLOCK_UNUSED); + tmp = radix_tree_tag_set(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); /* self-sanity check which should never fail */ WARN_ON(tmp != hwlock); out: mutex_unlock(&hwspinlock_tree_lock); - return ret; + return 0; } -EXPORT_SYMBOL_GPL(hwspin_lock_register); -/** - * hwspin_lock_unregister() - unregister an hw spinlock - * @id: index of the specific hwspinlock to unregister - * - * This function should be called from the underlying platform-specific - * implementation, to unregister an existing (and unused) hwspinlock. - * - * Should be called from a process context (might sleep) - * - * Returns the address of hwspinlock @id on success, or NULL on failure - */ -struct hwspinlock *hwspin_lock_unregister(unsigned int id) +static struct hwspinlock *hwspin_lock_unregister_single(unsigned int id) { struct hwspinlock *hwlock = NULL; int ret; @@ -337,6 +306,88 @@ out: mutex_unlock(&hwspinlock_tree_lock); return hwlock; } + +/** + * hwspin_lock_register() - register a new hw spinlock device + * @bank: the hwspinlock device, which usually provides numerous hw locks + * @dev: the backing device + * @ops: hwspinlock handlers for this device + * @base_id: id of the first hardware spinlock in this bank + * @num_locks: number of hwspinlocks provided by this device + * + * This function should be called from the underlying platform-specific + * implementation, to register a new hwspinlock device instance. + * + * Should be called from a process context (might sleep) + * + * Returns 0 on success, or an appropriate error code on failure + */ +int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, + const struct hwspinlock_ops *ops, int base_id, int num_locks) +{ + struct hwspinlock *hwlock; + int ret = 0, i; + + if (!bank || !ops || !dev || !num_locks || !ops->trylock || + !ops->unlock) { + pr_err("invalid parameters\n"); + return -EINVAL; + } + + bank->dev = dev; + bank->ops = ops; + bank->base_id = base_id; + bank->num_locks = num_locks; + + for (i = 0; i < num_locks; i++) { + hwlock = &bank->lock[i]; + + spin_lock_init(&hwlock->lock); + hwlock->bank = bank; + + ret = hwspin_lock_register_single(hwlock, i); + if (ret) + goto reg_failed; + } + + return 0; + +reg_failed: + while (--i >= 0) + hwspin_lock_unregister_single(i); + return ret; +} +EXPORT_SYMBOL_GPL(hwspin_lock_register); + +/** + * hwspin_lock_unregister() - unregister an hw spinlock device + * @bank: the hwspinlock device, which usually provides numerous hw locks + * + * This function should be called from the underlying platform-specific + * implementation, to unregister an existing (and unused) hwspinlock. + * + * Should be called from a process context (might sleep) + * + * Returns 0 on success, or an appropriate error code on failure + */ +int hwspin_lock_unregister(struct hwspinlock_device *bank) +{ + struct hwspinlock *hwlock, *tmp; + int i; + + for (i = 0; i < bank->num_locks; i++) { + hwlock = &bank->lock[i]; + + tmp = hwspin_lock_unregister_single(bank->base_id + i); + if (!tmp) + return -EBUSY; + + /* self-sanity check that should never fail */ + WARN_ON(tmp != hwlock); + } + + return 0; +} EXPORT_SYMBOL_GPL(hwspin_lock_unregister); /** @@ -351,24 +402,25 @@ EXPORT_SYMBOL_GPL(hwspin_lock_unregister); */ static int __hwspin_lock_request(struct hwspinlock *hwlock) { + struct device *dev = hwlock->bank->dev; struct hwspinlock *tmp; int ret; /* prevent underlying implementation from being removed */ - if (!try_module_get(hwlock->dev->driver->owner)) { - dev_err(hwlock->dev, "%s: can't get owner\n", __func__); + if (!try_module_get(dev->driver->owner)) { + dev_err(dev, "%s: can't get owner\n", __func__); return -EINVAL; } /* notify PM core that power is now needed */ - ret = pm_runtime_get_sync(hwlock->dev); + ret = pm_runtime_get_sync(dev); if (ret < 0) { - dev_err(hwlock->dev, "%s: can't power on device\n", __func__); + dev_err(dev, "%s: can't power on device\n", __func__); return ret; } /* mark hwspinlock as used, should not fail */ - tmp = radix_tree_tag_clear(&hwspinlock_tree, hwlock->id, + tmp = radix_tree_tag_clear(&hwspinlock_tree, hwlock_to_id(hwlock), HWSPINLOCK_UNUSED); /* self-sanity check that should never fail */ @@ -390,7 +442,7 @@ int hwspin_lock_get_id(struct hwspinlock *hwlock) return -EINVAL; } - return hwlock->id; + return hwlock_to_id(hwlock); } EXPORT_SYMBOL_GPL(hwspin_lock_get_id); @@ -465,7 +517,7 @@ struct hwspinlock *hwspin_lock_request_specific(unsigned int id) } /* sanity check (this shouldn't happen) */ - WARN_ON(hwlock->id != id); + WARN_ON(hwlock_to_id(hwlock) != id); /* make sure this hwspinlock is unused */ ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED); @@ -500,6 +552,7 @@ EXPORT_SYMBOL_GPL(hwspin_lock_request_specific); */ int hwspin_lock_free(struct hwspinlock *hwlock) { + struct device *dev = hwlock->bank->dev; struct hwspinlock *tmp; int ret; @@ -511,28 +564,28 @@ int hwspin_lock_free(struct hwspinlock *hwlock) mutex_lock(&hwspinlock_tree_lock); /* make sure the hwspinlock is used */ - ret = radix_tree_tag_get(&hwspinlock_tree, hwlock->id, + ret = radix_tree_tag_get(&hwspinlock_tree, hwlock_to_id(hwlock), HWSPINLOCK_UNUSED); if (ret == 1) { - dev_err(hwlock->dev, "%s: hwlock is already free\n", __func__); + dev_err(dev, "%s: hwlock is already free\n", __func__); dump_stack(); ret = -EINVAL; goto out; } /* notify the underlying device that power is not needed */ - ret = pm_runtime_put(hwlock->dev); + ret = pm_runtime_put(dev); if (ret < 0) goto out; /* mark this hwspinlock as available */ - tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock->id, + tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock_to_id(hwlock), HWSPINLOCK_UNUSED); /* sanity check (this shouldn't happen) */ WARN_ON(tmp != hwlock); - module_put(hwlock->dev->driver->owner); + module_put(dev->driver->owner); out: mutex_unlock(&hwspinlock_tree_lock); diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h index fb25830c2ee7..d26f78b8f214 100644 --- a/drivers/hwspinlock/hwspinlock_internal.h +++ b/drivers/hwspinlock/hwspinlock_internal.h @@ -21,6 +21,8 @@ #include #include +struct hwspinlock_device; + /** * struct hwspinlock_ops - platform-specific hwspinlock handlers * @@ -39,21 +41,37 @@ struct hwspinlock_ops { /** * struct hwspinlock - this struct represents a single hwspinlock instance - * - * @dev: underlying device, will be used to invoke runtime PM api - * @ops: platform-specific hwspinlock handlers - * @id: a global, unique, system-wide, index of the lock. + * @bank: the hwspinlock_device structure which owns this lock * @lock: initialized and used by hwspinlock core - * - * Note: currently simplicity was opted for, but later we can squeeze some - * memory bytes by grouping dev, ops in a single - * per-platform struct, and have all hwspinlocks point at it. + * @priv: private data, owned by the underlying platform-specific hwspinlock drv */ struct hwspinlock { - struct device *dev; - const struct hwspinlock_ops *ops; - int id; + struct hwspinlock_device *bank; spinlock_t lock; + void *priv; }; +/** + * 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_device { + struct device *dev; + const struct hwspinlock_ops *ops; + int base_id; + int num_locks; + struct hwspinlock lock[0]; +}; + +static inline int hwlock_to_id(struct hwspinlock *hwlock) +{ + int local_id = hwlock - &hwlock->bank->lock[0]; + + return hwlock->bank->base_id + local_id; +} + #endif /* __HWSPINLOCK_HWSPINLOCK_H */ diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c index 2044d181e49d..aec30064a466 100644 --- a/drivers/hwspinlock/omap_hwspinlock.c +++ b/drivers/hwspinlock/omap_hwspinlock.c @@ -41,34 +41,20 @@ #define SPINLOCK_NOTTAKEN (0) /* free */ #define SPINLOCK_TAKEN (1) /* locked */ -#define to_omap_hwspinlock(lock) \ - container_of(lock, struct omap_hwspinlock, lock) - -struct omap_hwspinlock { - struct hwspinlock lock; - void __iomem *addr; -}; - -struct omap_hwspinlock_state { - int num_locks; /* Total number of locks in system */ - void __iomem *io_base; /* Mapped base address */ - struct omap_hwspinlock lock[0]; /* Array of 'num_locks' locks */ -}; - static int omap_hwspinlock_trylock(struct hwspinlock *lock) { - struct omap_hwspinlock *omap_lock = to_omap_hwspinlock(lock); + void __iomem *lock_addr = lock->priv; /* attempt to acquire the lock by reading its value */ - return (SPINLOCK_NOTTAKEN == readl(omap_lock->addr)); + return (SPINLOCK_NOTTAKEN == readl(lock_addr)); } static void omap_hwspinlock_unlock(struct hwspinlock *lock) { - struct omap_hwspinlock *omap_lock = to_omap_hwspinlock(lock); + void __iomem *lock_addr = lock->priv; /* release the lock by writing 0 to it */ - writel(SPINLOCK_NOTTAKEN, omap_lock->addr); + writel(SPINLOCK_NOTTAKEN, lock_addr); } /* @@ -95,11 +81,11 @@ static const struct hwspinlock_ops omap_hwspinlock_ops = { static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) { struct hwspinlock_pdata *pdata = pdev->dev.platform_data; - struct omap_hwspinlock *omap_lock; - struct omap_hwspinlock_state *state; + struct hwspinlock_device *bank; + struct hwspinlock *hwlock; struct resource *res; void __iomem *io_base; - int i, ret; + int num_locks, i, ret; if (!pdata) return -ENODEV; @@ -122,18 +108,18 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) goto iounmap_base; } - i *= 32; /* actual number of locks in this device */ + num_locks = i * 32; /* actual number of locks in this device */ - state = kzalloc(sizeof(*state) + i * sizeof(*omap_lock), GFP_KERNEL); - if (!state) { + bank = kzalloc(sizeof(*bank) + num_locks * sizeof(*hwlock), GFP_KERNEL); + if (!bank) { ret = -ENOMEM; goto iounmap_base; } - state->num_locks = i; - state->io_base = io_base; + platform_set_drvdata(pdev, bank); - platform_set_drvdata(pdev, state); + for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++) + hwlock->priv = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i; /* * runtime PM will make sure the clock of this module is @@ -141,26 +127,16 @@ static int __devinit omap_hwspinlock_probe(struct platform_device *pdev) */ pm_runtime_enable(&pdev->dev); - for (i = 0; i < state->num_locks; i++) { - omap_lock = &state->lock[i]; - - omap_lock->lock.dev = &pdev->dev; - omap_lock->lock.id = pdata->base_id + i; - omap_lock->lock.ops = &omap_hwspinlock_ops; - omap_lock->addr = io_base + LOCK_BASE_OFFSET + sizeof(u32) * i; - - ret = hwspin_lock_register(&omap_lock->lock); - if (ret) - goto free_locks; - } + ret = hwspin_lock_register(bank, &pdev->dev, &omap_hwspinlock_ops, + pdata->base_id, num_locks); + if (ret) + goto reg_fail; return 0; -free_locks: - while (--i >= 0) - hwspin_lock_unregister(i); +reg_fail: pm_runtime_disable(&pdev->dev); - kfree(state); + kfree(bank); iounmap_base: iounmap(io_base); return ret; @@ -168,23 +144,19 @@ iounmap_base: static int omap_hwspinlock_remove(struct platform_device *pdev) { - struct omap_hwspinlock_state *state = platform_get_drvdata(pdev); - struct hwspinlock *lock; - int i; + struct hwspinlock_device *bank = platform_get_drvdata(pdev); + void __iomem *io_base = bank->lock[0].priv - LOCK_BASE_OFFSET; + int ret; - for (i = 0; i < state->num_locks; i++) { - lock = hwspin_lock_unregister(i); - /* this shouldn't happen at this point. if it does, at least - * don't continue with the remove */ - if (!lock) { - dev_err(&pdev->dev, "%s: failed on %d\n", __func__, i); - return -EBUSY; - } + ret = hwspin_lock_unregister(bank); + if (ret) { + dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret); + return ret; } pm_runtime_disable(&pdev->dev); - iounmap(state->io_base); - kfree(state); + iounmap(io_base); + kfree(bank); return 0; } diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h index c246522a9551..08a2fee40659 100644 --- a/include/linux/hwspinlock.h +++ b/include/linux/hwspinlock.h @@ -20,12 +20,15 @@ #include #include +#include /* hwspinlock mode argument */ #define HWLOCK_IRQSTATE 0x01 /* Disable interrupts, save state */ #define HWLOCK_IRQ 0x02 /* Disable interrupts, don't save state */ struct hwspinlock; +struct hwspinlock_device; +struct hwspinlock_ops; /** * struct hwspinlock_pdata - platform data for hwspinlock drivers @@ -57,8 +60,9 @@ struct hwspinlock_pdata { #if defined(CONFIG_HWSPINLOCK) || defined(CONFIG_HWSPINLOCK_MODULE) -int hwspin_lock_register(struct hwspinlock *lock); -struct hwspinlock *hwspin_lock_unregister(unsigned int id); +int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, + const struct hwspinlock_ops *ops, int base_id, int num_locks); +int hwspin_lock_unregister(struct hwspinlock_device *bank); struct hwspinlock *hwspin_lock_request(void); struct hwspinlock *hwspin_lock_request_specific(unsigned int id); int hwspin_lock_free(struct hwspinlock *hwlock); From f84a8ecfca9229e9227c6ec84123b114ee634959 Mon Sep 17 00:00:00 2001 From: "Mathieu J. Poirier" Date: Thu, 8 Sep 2011 22:47:40 +0300 Subject: [PATCH 08/10] hwspinlock/u8500: add hwspinlock driver Add hwspinlock driver for U8500's Hsem hardware. At this point only HSem's protocol 1 is used (i.e. no interrupts). Signed-off-by: Mathieu Poirier Acked-by: Linus Walleij [ohad@wizery.com: adopt recent hwspin_lock_{un}register API changes] [ohad@wizery.com: set the owner member of the driver] [ohad@wizery.com: mark ->remove() function as __devexit] [ohad@wizery.com: write commit log] [ohad@wizery.com: small cleanups] Signed-off-by: Ohad Ben-Cohen --- drivers/hwspinlock/Kconfig | 11 ++ drivers/hwspinlock/Makefile | 1 + drivers/hwspinlock/u8500_hsem.c | 198 ++++++++++++++++++++++++++++++++ 3 files changed, 210 insertions(+) create mode 100644 drivers/hwspinlock/u8500_hsem.c diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig index c8e7bdac1404..c7c3128393d1 100644 --- a/drivers/hwspinlock/Kconfig +++ b/drivers/hwspinlock/Kconfig @@ -18,4 +18,15 @@ config HWSPINLOCK_OMAP 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 diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile index 5729a3f7ed3d..93eb64b66486 100644 --- a/drivers/hwspinlock/Makefile +++ b/drivers/hwspinlock/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_HWSPINLOCK) += hwspinlock_core.o obj-$(CONFIG_HWSPINLOCK_OMAP) += omap_hwspinlock.o +obj-$(CONFIG_HSEM_U8500) += u8500_hsem.o diff --git a/drivers/hwspinlock/u8500_hsem.c b/drivers/hwspinlock/u8500_hsem.c new file mode 100644 index 000000000000..143461a95ae4 --- /dev/null +++ b/drivers/hwspinlock/u8500_hsem.c @@ -0,0 +1,198 @@ +/* + * u8500 HWSEM driver + * + * Copyright (C) 2010-2011 ST-Ericsson + * + * Implements u8500 semaphore handling for protocol 1, no interrupts. + * + * Author: Mathieu Poirier + * Heavily borrowed from the work of : + * Simon Que + * Hari Kanigeri + * Ohad Ben-Cohen + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "hwspinlock_internal.h" + +/* + * Implementation of STE's HSem protocol 1 without interrutps. + * The only masterID we allow is '0x01' to force people to use + * HSems for synchronisation between processors rather than processes + * on the ARM core. + */ + +#define U8500_MAX_SEMAPHORE 32 /* a total of 32 semaphore */ +#define RESET_SEMAPHORE (0) /* free */ + +/* + * CPU ID for master running u8500 kernel. + * Hswpinlocks should only be used to synchonise operations + * between the Cortex A9 core and the other CPUs. Hence + * forcing the masterID to a preset value. + */ +#define HSEM_MASTER_ID 0x01 + +#define HSEM_REGISTER_OFFSET 0x08 + +#define HSEM_CTRL_REG 0x00 +#define HSEM_ICRALL 0x90 +#define HSEM_PROTOCOL_1 0x01 + +static int u8500_hsem_trylock(struct hwspinlock *lock) +{ + void __iomem *lock_addr = lock->priv; + + writel(HSEM_MASTER_ID, lock_addr); + + /* get only first 4 bit and compare to masterID. + * if equal, we have the semaphore, otherwise + * someone else has it. + */ + return (HSEM_MASTER_ID == (0x0F & readl(lock_addr))); +} + +static void u8500_hsem_unlock(struct hwspinlock *lock) +{ + void __iomem *lock_addr = lock->priv; + + /* release the lock by writing 0 to it */ + writel(RESET_SEMAPHORE, lock_addr); +} + +/* + * u8500: what value is recommended here ? + */ +static void u8500_hsem_relax(struct hwspinlock *lock) +{ + ndelay(50); +} + +static const struct hwspinlock_ops u8500_hwspinlock_ops = { + .trylock = u8500_hsem_trylock, + .unlock = u8500_hsem_unlock, + .relax = u8500_hsem_relax, +}; + +static int __devinit u8500_hsem_probe(struct platform_device *pdev) +{ + struct hwspinlock_pdata *pdata = pdev->dev.platform_data; + struct hwspinlock_device *bank; + struct hwspinlock *hwlock; + struct resource *res; + void __iomem *io_base; + int i, ret, num_locks = U8500_MAX_SEMAPHORE; + ulong val; + + if (!pdata) + return -ENODEV; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENODEV; + + io_base = ioremap(res->start, resource_size(res)); + if (!io_base) { + ret = -ENOMEM; + goto free_state; + } + + /* make sure protocol 1 is selected */ + val = readl(io_base + HSEM_CTRL_REG); + writel((val & ~HSEM_PROTOCOL_1), io_base + HSEM_CTRL_REG); + + /* clear all interrupts */ + writel(0xFFFF, io_base + HSEM_ICRALL); + + bank = kzalloc(sizeof(*bank) + num_locks * sizeof(*hwlock), GFP_KERNEL); + if (!bank) { + ret = -ENOMEM; + goto iounmap_base; + } + + platform_set_drvdata(pdev, bank); + + for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++) + hwlock->priv = io_base + HSEM_REGISTER_OFFSET + sizeof(u32) * i; + + /* no pm needed for HSem but required to comply with hwspilock core */ + pm_runtime_enable(&pdev->dev); + + ret = hwspin_lock_register(bank, &pdev->dev, &u8500_hwspinlock_ops, + pdata->base_id, num_locks); + if (ret) + goto reg_fail; + + return 0; + +reg_fail: + pm_runtime_disable(&pdev->dev); + kfree(bank); +iounmap_base: + iounmap(io_base); + return ret; +} + +static int __devexit u8500_hsem_remove(struct platform_device *pdev) +{ + struct hwspinlock_device *bank = platform_get_drvdata(pdev); + void __iomem *io_base = bank->lock[0].priv - HSEM_REGISTER_OFFSET; + int ret; + + /* clear all interrupts */ + writel(0xFFFF, io_base + HSEM_ICRALL); + + ret = hwspin_lock_unregister(bank); + if (ret) { + dev_err(&pdev->dev, "%s failed: %d\n", __func__, ret); + return ret; + } + + pm_runtime_disable(&pdev->dev); + iounmap(io_base); + kfree(bank); + + return 0; +} + +static struct platform_driver u8500_hsem_driver = { + .probe = u8500_hsem_probe, + .remove = __devexit_p(u8500_hsem_remove), + .driver = { + .name = "u8500_hsem", + .owner = THIS_MODULE, + }, +}; + +static int __init u8500_hsem_init(void) +{ + return platform_driver_register(&u8500_hsem_driver); +} +/* board init code might need to reserve hwspinlocks for predefined purposes */ +postcore_initcall(u8500_hsem_init); + +static void __exit u8500_hsem_exit(void) +{ + platform_driver_unregister(&u8500_hsem_driver); +} +module_exit(u8500_hsem_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Hardware Spinlock driver for u8500"); +MODULE_AUTHOR("Mathieu Poirier "); From 9efb4a1bb9e46d26a15116e3c72b1b81c62d8337 Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Sun, 11 Sep 2011 18:54:50 +0300 Subject: [PATCH 09/10] hwspinlock/omap: omap_hwspinlock_remove should be __devexit Mark omap_hwspinlock_remove with __devexit (and use __devexit_p appropriately) so the function can be discarded when the conditions are met. Signed-off-by: Ohad Ben-Cohen --- drivers/hwspinlock/omap_hwspinlock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hwspinlock/omap_hwspinlock.c b/drivers/hwspinlock/omap_hwspinlock.c index aec30064a466..887d34effb3a 100644 --- a/drivers/hwspinlock/omap_hwspinlock.c +++ b/drivers/hwspinlock/omap_hwspinlock.c @@ -142,7 +142,7 @@ iounmap_base: return ret; } -static int omap_hwspinlock_remove(struct platform_device *pdev) +static int __devexit omap_hwspinlock_remove(struct platform_device *pdev) { struct hwspinlock_device *bank = platform_get_drvdata(pdev); void __iomem *io_base = bank->lock[0].priv - LOCK_BASE_OFFSET; @@ -163,7 +163,7 @@ static int omap_hwspinlock_remove(struct platform_device *pdev) static struct platform_driver omap_hwspinlock_driver = { .probe = omap_hwspinlock_probe, - .remove = omap_hwspinlock_remove, + .remove = __devexit_p(omap_hwspinlock_remove), .driver = { .name = "omap_hwspinlock", .owner = THIS_MODULE, From 8b37fcfc9b3400b647748783a2cafff67793e0ad Mon Sep 17 00:00:00 2001 From: Ohad Ben-Cohen Date: Mon, 12 Sep 2011 10:43:01 +0300 Subject: [PATCH 10/10] hwspinlock: add MAINTAINERS entries Update MAINTAINERS with entries for hwspinlock/core and hwspinlock/omap files. Signed-off-by: Ohad Ben-Cohen --- MAINTAINERS | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/MAINTAINERS b/MAINTAINERS index 28f65c249b97..c79a96692d98 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2953,6 +2953,13 @@ F: Documentation/hw_random.txt F: drivers/char/hw_random/ F: include/linux/hw_random.h +HARDWARE SPINLOCK CORE +M: Ohad Ben-Cohen +S: Maintained +F: Documentation/hwspinlock.txt +F: drivers/hwspinlock/hwspinlock_* +F: include/linux/hwspinlock.h + HARMONY SOUND DRIVER M: Kyle McMartin L: linux-parisc@vger.kernel.org @@ -4625,6 +4632,13 @@ S: Maintained F: drivers/video/omap2/ F: Documentation/arm/OMAP/DSS +OMAP HARDWARE SPINLOCK SUPPORT +M: Ohad Ben-Cohen +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 L: linux-omap@vger.kernel.org