Commit 07ec3891 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jason Gunthorpe
Browse files

mm: remove the struct hmm_device infrastructure 



This code is a trivial wrapper around device model helpers, which
should have been integrated into the driver device model usage from
the start.  Assuming it actually had users, which it never had since
the code was added more than 1 1/2 years ago.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent c2561e65

include/linux/hmm.h

+0 −20
Original line number Diff line number Diff line
@@ -751,26 +751,6 @@ static inline unsigned long hmm_devmem_page_get_drvdata(const struct page *page) 
{

	return page->hmm_data;

}





/*

 * struct hmm_device - fake device to hang device memory onto

 *

 * @device: device struct

 * @minor: device minor number

 */

struct hmm_device {

	struct device		device;

	unsigned int		minor;

};



/*

 * A device driver that wants to handle multiple devices memory through a

 * single fake device can use hmm_device to do so. This is purely a helper and

 * it is not strictly needed, in order to make use of any HMM functionality.

 */

struct hmm_device *hmm_device_new(void *drvdata);

void hmm_device_put(struct hmm_device *hmm_device);

#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */

#else /* IS_ENABLED(CONFIG_HMM) */

static inline void hmm_mm_destroy(struct mm_struct *mm) {}

mm/hmm.c

+0 −80
Original line number Diff line number Diff line
@@ -1528,84 +1528,4 @@ struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops, 
	return devmem;

}

EXPORT_SYMBOL_GPL(hmm_devmem_add_resource);



/*

 * A device driver that wants to handle multiple devices memory through a

 * single fake device can use hmm_device to do so. This is purely a helper

 * and it is not needed to make use of any HMM functionality.

 */

#define HMM_DEVICE_MAX 256



static DECLARE_BITMAP(hmm_device_mask, HMM_DEVICE_MAX);

static DEFINE_SPINLOCK(hmm_device_lock);

static struct class *hmm_device_class;

static dev_t hmm_device_devt;



static void hmm_device_release(struct device *device)

{

	struct hmm_device *hmm_device;



	hmm_device = container_of(device, struct hmm_device, device);

	spin_lock(&hmm_device_lock);

	clear_bit(hmm_device->minor, hmm_device_mask);

	spin_unlock(&hmm_device_lock);



	kfree(hmm_device);

}



struct hmm_device *hmm_device_new(void *drvdata)

{

	struct hmm_device *hmm_device;



	hmm_device = kzalloc(sizeof(*hmm_device), GFP_KERNEL);

	if (!hmm_device)

		return ERR_PTR(-ENOMEM);



	spin_lock(&hmm_device_lock);

	hmm_device->minor = find_first_zero_bit(hmm_device_mask, HMM_DEVICE_MAX);

	if (hmm_device->minor >= HMM_DEVICE_MAX) {

		spin_unlock(&hmm_device_lock);

		kfree(hmm_device);

		return ERR_PTR(-EBUSY);

	}

	set_bit(hmm_device->minor, hmm_device_mask);

	spin_unlock(&hmm_device_lock);



	dev_set_name(&hmm_device->device, "hmm_device%d", hmm_device->minor);

	hmm_device->device.devt = MKDEV(MAJOR(hmm_device_devt),

					hmm_device->minor);

	hmm_device->device.release = hmm_device_release;

	dev_set_drvdata(&hmm_device->device, drvdata);

	hmm_device->device.class = hmm_device_class;

	device_initialize(&hmm_device->device);



	return hmm_device;

}

EXPORT_SYMBOL(hmm_device_new);



void hmm_device_put(struct hmm_device *hmm_device)

{

	put_device(&hmm_device->device);

}

EXPORT_SYMBOL(hmm_device_put);



static int __init hmm_init(void)

{

	int ret;



	ret = alloc_chrdev_region(&hmm_device_devt, 0,

				  HMM_DEVICE_MAX,

				  "hmm_device");

	if (ret)

		return ret;



	hmm_device_class = class_create(THIS_MODULE, "hmm_device");

	if (IS_ERR(hmm_device_class)) {

		unregister_chrdev_region(hmm_device_devt, HMM_DEVICE_MAX);

		return PTR_ERR(hmm_device_class);

	}

	return 0;

}



device_initcall(hmm_init);

#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */

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