diff options
| -rw-r--r-- | Documentation/driver-model/devres.txt | 2 | ||||
| -rw-r--r-- | drivers/base/devres.c | 76 | ||||
| -rw-r--r-- | include/linux/device.h | 4 |
3 files changed, 82 insertions, 0 deletions
diff --git a/Documentation/driver-model/devres.txt b/Documentation/driver-model/devres.txt index 499951873997..e1a27074caae 100644 --- a/Documentation/driver-model/devres.txt +++ b/Documentation/driver-model/devres.txt @@ -237,6 +237,8 @@ MEM devm_kzalloc() devm_kfree() devm_kmemdup() + devm_get_free_pages() + devm_free_pages() IIO devm_iio_device_alloc() diff --git a/drivers/base/devres.c b/drivers/base/devres.c index d0914cba2413..52302946770f 100644 --- a/drivers/base/devres.c +++ b/drivers/base/devres.c @@ -852,3 +852,79 @@ void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp) return p; } EXPORT_SYMBOL_GPL(devm_kmemdup); + +struct pages_devres { + unsigned long addr; + unsigned int order; +}; + +static int devm_pages_match(struct device *dev, void *res, void *p) +{ + struct pages_devres *devres = res; + struct pages_devres *target = p; + + return devres->addr == target->addr; +} + +static void devm_pages_release(struct device *dev, void *res) +{ + struct pages_devres *devres = res; + + free_pages(devres->addr, devres->order); +} + +/** + * devm_get_free_pages - Resource-managed __get_free_pages + * @dev: Device to allocate memory for + * @gfp_mask: Allocation gfp flags + * @order: Allocation size is (1 << order) pages + * + * Managed get_free_pages. Memory allocated with this function is + * automatically freed on driver detach. + * + * RETURNS: + * Address of allocated memory on success, 0 on failure. + */ + +unsigned long devm_get_free_pages(struct device *dev, + gfp_t gfp_mask, unsigned int order) +{ + struct pages_devres *devres; + unsigned long addr; + + addr = __get_free_pages(gfp_mask, order); + + if (unlikely(!addr)) + return 0; + + devres = devres_alloc(devm_pages_release, + sizeof(struct pages_devres), GFP_KERNEL); + if (unlikely(!devres)) { + free_pages(addr, order); + return 0; + } + + devres->addr = addr; + devres->order = order; + + devres_add(dev, devres); + return addr; +} +EXPORT_SYMBOL_GPL(devm_get_free_pages); + +/** + * devm_free_pages - Resource-managed free_pages + * @dev: Device this memory belongs to + * @addr: Memory to free + * + * Free memory allocated with devm_get_free_pages(). Unlike free_pages, + * there is no need to supply the @order. + */ +void devm_free_pages(struct device *dev, unsigned long addr) +{ + struct pages_devres devres = { .addr = addr }; + + WARN_ON(devres_release(dev, devm_pages_release, devm_pages_match, + &devres)); +} +EXPORT_SYMBOL_GPL(devm_free_pages); diff --git a/include/linux/device.h b/include/linux/device.h index ab871588da89..3dc69a2faa51 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -626,6 +626,10 @@ extern char *devm_kstrdup(struct device *dev, const char *s, gfp_t gfp); extern void *devm_kmemdup(struct device *dev, const void *src, size_t len, gfp_t gfp); +extern unsigned long devm_get_free_pages(struct device *dev, + gfp_t gfp_mask, unsigned int order); +extern void devm_free_pages(struct device *dev, unsigned long addr); + void __iomem *devm_ioremap_resource(struct device *dev, struct resource *res); void __iomem *devm_request_and_ioremap(struct device *dev, struct resource *res); |