Commit 6869b7b2 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jason Gunthorpe
Browse files

memremap: provide a not device managed memremap_pages 

The kvmppc ultravisor code wants a device private memory pool that is
system wide and not attached to a device.  Instead of faking up one
provide a low-level memremap_pages for it.

Link: https://lore.kernel.org/r/20190818090557.17853-5-hch@lst.de


Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Reviewed-by: default avatarDan Williams <dan.j.williams@intel.com>
Tested-by: default avatarBharata B Rao <bharata@linux.ibm.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 6f42193f

include/linux/memremap.h

+2 −0
Original line number Diff line number Diff line
@@ -123,6 +123,8 @@ static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap) 
}



#ifdef CONFIG_ZONE_DEVICE

void *memremap_pages(struct dev_pagemap *pgmap, int nid);

void memunmap_pages(struct dev_pagemap *pgmap);

void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap);

void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap);

struct dev_pagemap *get_dev_pagemap(unsigned long pfn,

kernel/memremap.c

+52 −32
Original line number Diff line number Diff line
@@ -96,9 +96,8 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap) 
	}

}



static void devm_memremap_pages_release(void *data)

void memunmap_pages(struct dev_pagemap *pgmap)

{

	struct dev_pagemap *pgmap = data;

	struct resource *res = &pgmap->res;

	unsigned long pfn;

	int nid;
@@ -128,6 +127,12 @@ static void devm_memremap_pages_release(void *data) 
	WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");

	devmap_managed_enable_put();

}

EXPORT_SYMBOL_GPL(memunmap_pages);



static void devm_memremap_pages_release(void *data)

{

	memunmap_pages(data);

}



static void dev_pagemap_percpu_release(struct percpu_ref *ref)

{
@@ -137,27 +142,12 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref) 
	complete(&pgmap->done);

}



/**

 * devm_memremap_pages - remap and provide memmap backing for the given resource

 * @dev: hosting device for @res

 * @pgmap: pointer to a struct dev_pagemap

 *

 * Notes:

 * 1/ At a minimum the res and type members of @pgmap must be initialized

 *    by the caller before passing it to this function

 *

 * 2/ The altmap field may optionally be initialized, in which case

 *    PGMAP_ALTMAP_VALID must be set in pgmap->flags.

 *

 * 3/ The ref field may optionally be provided, in which pgmap->ref must be

 *    'live' on entry and will be killed and reaped at

 *    devm_memremap_pages_release() time, or if this routine fails.

 *

 * 4/ res is expected to be a host memory range that could feasibly be

 *    treated as a "System RAM" range, i.e. not a device mmio range, but

 *    this is not enforced.

/*

 * Not device managed version of dev_memremap_pages, undone by

 * memunmap_pages().  Please use dev_memremap_pages if you have a struct

 * device available.

 */

void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)

void *memremap_pages(struct dev_pagemap *pgmap, int nid)

{

	struct resource *res = &pgmap->res;

	struct dev_pagemap *conflict_pgmap;
@@ -168,7 +158,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) 
		.altmap = pgmap_altmap(pgmap),

	};

	pgprot_t pgprot = PAGE_KERNEL;

	int error, nid, is_ram;

	int error, is_ram;

	bool need_devmap_managed = true;



	switch (pgmap->type) {
@@ -223,7 +213,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) 


	conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->start), NULL);

	if (conflict_pgmap) {

		dev_WARN(dev, "Conflicting mapping in same section\n");

		WARN(1, "Conflicting mapping in same section\n");

		put_dev_pagemap(conflict_pgmap);

		error = -ENOMEM;

		goto err_array;
@@ -231,7 +221,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) 


	conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->end), NULL);

	if (conflict_pgmap) {

		dev_WARN(dev, "Conflicting mapping in same section\n");

		WARN(1, "Conflicting mapping in same section\n");

		put_dev_pagemap(conflict_pgmap);

		error = -ENOMEM;

		goto err_array;
@@ -252,7 +242,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) 
	if (error)

		goto err_array;



	nid = dev_to_node(dev);

	if (nid < 0)

		nid = numa_mem_id();
@@ -308,12 +297,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) 
				PHYS_PFN(res->start),

				PHYS_PFN(resource_size(res)), pgmap);

	percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap));



	error = devm_add_action_or_reset(dev, devm_memremap_pages_release,

			pgmap);

	if (error)

		return ERR_PTR(error);



	return __va(res->start);



 err_add_memory:
@@ -328,6 +311,43 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) 
	devmap_managed_enable_put();

	return ERR_PTR(error);

}

EXPORT_SYMBOL_GPL(memremap_pages);



/**

 * devm_memremap_pages - remap and provide memmap backing for the given resource

 * @dev: hosting device for @res

 * @pgmap: pointer to a struct dev_pagemap

 *

 * Notes:

 * 1/ At a minimum the res and type members of @pgmap must be initialized

 *    by the caller before passing it to this function

 *

 * 2/ The altmap field may optionally be initialized, in which case

 *    PGMAP_ALTMAP_VALID must be set in pgmap->flags.

 *

 * 3/ The ref field may optionally be provided, in which pgmap->ref must be

 *    'live' on entry and will be killed and reaped at

 *    devm_memremap_pages_release() time, or if this routine fails.

 *

 * 4/ res is expected to be a host memory range that could feasibly be

 *    treated as a "System RAM" range, i.e. not a device mmio range, but

 *    this is not enforced.

 */

void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)

{

	int error;

	void *ret;



	ret = memremap_pages(pgmap, dev_to_node(dev));

	if (IS_ERR(ret))

		return ret;



	error = devm_add_action_or_reset(dev, devm_memremap_pages_release,

			pgmap);

	if (error)

		return ERR_PTR(error);

	return ret;

}

EXPORT_SYMBOL_GPL(devm_memremap_pages);



void devm_memunmap_pages(struct device *dev, struct dev_pagemap *pgmap)

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