[03/22] mm: remove hmm_devmem_add_resource

Submitted by Christoph Hellwig on June 13, 2019, 9:43 a.m.

Details

Message ID 20190613094326.24093-4-hch@lst.de
State New
Headers show
Series "Series without cover letter" ( rev: 3 2 1 ) in Nouveau

Not browsing as part of any series.

Commit Message

Christoph Hellwig June 13, 2019, 9:43 a.m.
This function has never been used since it was first added to the kernel
more than a year and a half ago, and if we ever grow a consumer of the
MEMORY_DEVICE_PUBLIC infrastructure it can easily use devm_memremap_pages
directly now that we've simplified the API for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/hmm.h |  3 ---
 mm/hmm.c            | 54 ---------------------------------------------
 2 files changed, 57 deletions(-)

Patch hide | download patch | download mbox

diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index 4867b9da1b6c..5761a39221a6 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -688,9 +688,6 @@  struct hmm_devmem {
 struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops,
 				  struct device *device,
 				  unsigned long size);
-struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops,
-					   struct device *device,
-					   struct resource *res);
 
 /*
  * hmm_devmem_page_set_drvdata - set per-page driver data field
diff --git a/mm/hmm.c b/mm/hmm.c
index ff2598eb7377..0c62426d1257 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -1445,58 +1445,4 @@  struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops,
 	return devmem;
 }
 EXPORT_SYMBOL_GPL(hmm_devmem_add);
-
-struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops,
-					   struct device *device,
-					   struct resource *res)
-{
-	struct hmm_devmem *devmem;
-	void *result;
-	int ret;
-
-	if (res->desc != IORES_DESC_DEVICE_PUBLIC_MEMORY)
-		return ERR_PTR(-EINVAL);
-
-	dev_pagemap_get_ops();
-
-	devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL);
-	if (!devmem)
-		return ERR_PTR(-ENOMEM);
-
-	init_completion(&devmem->completion);
-	devmem->pfn_first = -1UL;
-	devmem->pfn_last = -1UL;
-	devmem->resource = res;
-	devmem->device = device;
-	devmem->ops = ops;
-
-	ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release,
-			      0, GFP_KERNEL);
-	if (ret)
-		return ERR_PTR(ret);
-
-	ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit,
-			&devmem->ref);
-	if (ret)
-		return ERR_PTR(ret);
-
-	devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT;
-	devmem->pfn_last = devmem->pfn_first +
-			   (resource_size(devmem->resource) >> PAGE_SHIFT);
-	devmem->page_fault = hmm_devmem_fault;
-
-	devmem->pagemap.type = MEMORY_DEVICE_PUBLIC;
-	devmem->pagemap.res = *devmem->resource;
-	devmem->pagemap.page_free = hmm_devmem_free;
-	devmem->pagemap.altmap_valid = false;
-	devmem->pagemap.ref = &devmem->ref;
-	devmem->pagemap.data = devmem;
-	devmem->pagemap.kill = hmm_devmem_ref_kill;
-
-	result = devm_memremap_pages(devmem->device, &devmem->pagemap);
-	if (IS_ERR(result))
-		return result;
-	return devmem;
-}
-EXPORT_SYMBOL_GPL(hmm_devmem_add_resource);
 #endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */

Comments

On Thu, Jun 13, 2019 at 11:43:06AM +0200, Christoph Hellwig wrote:
> This function has never been used since it was first added to the kernel
> more than a year and a half ago, and if we ever grow a consumer of the
> MEMORY_DEVICE_PUBLIC infrastructure it can easily use devm_memremap_pages
> directly now that we've simplified the API for it.

nit: Have we simplified the interface for devm_memremap_pages() at
this point, or are you talking about later patches in this series.

I checked this and all the called functions are exported symbols, so
there is no blocker for a future driver to call devm_memremap_pages(),
maybe even with all this boiler plate, in future.

If we eventually get many users that need some simplified registration
then we should add a devm_memremap_pages_simplified() interface and
factor out that code when we can see the pattern.

Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>

Jason
On 6/13/19 2:43 AM, Christoph Hellwig wrote:
> This function has never been used since it was first added to the kernel
> more than a year and a half ago, and if we ever grow a consumer of the
> MEMORY_DEVICE_PUBLIC infrastructure it can easily use devm_memremap_pages
> directly now that we've simplified the API for it.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  include/linux/hmm.h |  3 ---
>  mm/hmm.c            | 54 ---------------------------------------------
>  2 files changed, 57 deletions(-)
> 

No objections here, good cleanup.

Reviewed-by: John Hubbard <jhubbard@nvidia.com> 

thanks,
On Thu, Jun 13, 2019 at 06:52:44PM +0000, Jason Gunthorpe wrote:
> On Thu, Jun 13, 2019 at 11:43:06AM +0200, Christoph Hellwig wrote:
> > This function has never been used since it was first added to the kernel
> > more than a year and a half ago, and if we ever grow a consumer of the
> > MEMORY_DEVICE_PUBLIC infrastructure it can easily use devm_memremap_pages
> > directly now that we've simplified the API for it.
> 
> nit: Have we simplified the interface for devm_memremap_pages() at
> this point, or are you talking about later patches in this series.

After this series.  I've just droped that part of the sentence to
avoid confusion.

> I checked this and all the called functions are exported symbols, so
> there is no blocker for a future driver to call devm_memremap_pages(),
> maybe even with all this boiler plate, in future.
> 
> If we eventually get many users that need some simplified registration
> then we should add a devm_memremap_pages_simplified() interface and
> factor out that code when we can see the pattern.

After this series devm_memremap_pages already is simpler to use than
hmm_device_add_resource was before, so I'm not worried at all.  The
series actually net removes lines from noveau (if only a few).
On Thu 13-06-19 11:43:06, Christoph Hellwig wrote:
> This function has never been used since it was first added to the kernel
> more than a year and a half ago, and if we ever grow a consumer of the
> MEMORY_DEVICE_PUBLIC infrastructure it can easily use devm_memremap_pages
> directly now that we've simplified the API for it.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
>  include/linux/hmm.h |  3 ---
>  mm/hmm.c            | 54 ---------------------------------------------
>  2 files changed, 57 deletions(-)
> 
> diff --git a/include/linux/hmm.h b/include/linux/hmm.h
> index 4867b9da1b6c..5761a39221a6 100644
> --- a/include/linux/hmm.h
> +++ b/include/linux/hmm.h
> @@ -688,9 +688,6 @@ struct hmm_devmem {
>  struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops,
>  				  struct device *device,
>  				  unsigned long size);
> -struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops,
> -					   struct device *device,
> -					   struct resource *res);
>  
>  /*
>   * hmm_devmem_page_set_drvdata - set per-page driver data field
> diff --git a/mm/hmm.c b/mm/hmm.c
> index ff2598eb7377..0c62426d1257 100644
> --- a/mm/hmm.c
> +++ b/mm/hmm.c
> @@ -1445,58 +1445,4 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops,
>  	return devmem;
>  }
>  EXPORT_SYMBOL_GPL(hmm_devmem_add);
> -
> -struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops,
> -					   struct device *device,
> -					   struct resource *res)
> -{
> -	struct hmm_devmem *devmem;
> -	void *result;
> -	int ret;
> -
> -	if (res->desc != IORES_DESC_DEVICE_PUBLIC_MEMORY)
> -		return ERR_PTR(-EINVAL);
> -
> -	dev_pagemap_get_ops();
> -
> -	devmem = devm_kzalloc(device, sizeof(*devmem), GFP_KERNEL);
> -	if (!devmem)
> -		return ERR_PTR(-ENOMEM);
> -
> -	init_completion(&devmem->completion);
> -	devmem->pfn_first = -1UL;
> -	devmem->pfn_last = -1UL;
> -	devmem->resource = res;
> -	devmem->device = device;
> -	devmem->ops = ops;
> -
> -	ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release,
> -			      0, GFP_KERNEL);
> -	if (ret)
> -		return ERR_PTR(ret);
> -
> -	ret = devm_add_action_or_reset(device, hmm_devmem_ref_exit,
> -			&devmem->ref);
> -	if (ret)
> -		return ERR_PTR(ret);
> -
> -	devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT;
> -	devmem->pfn_last = devmem->pfn_first +
> -			   (resource_size(devmem->resource) >> PAGE_SHIFT);
> -	devmem->page_fault = hmm_devmem_fault;
> -
> -	devmem->pagemap.type = MEMORY_DEVICE_PUBLIC;
> -	devmem->pagemap.res = *devmem->resource;
> -	devmem->pagemap.page_free = hmm_devmem_free;
> -	devmem->pagemap.altmap_valid = false;
> -	devmem->pagemap.ref = &devmem->ref;
> -	devmem->pagemap.data = devmem;
> -	devmem->pagemap.kill = hmm_devmem_ref_kill;
> -
> -	result = devm_memremap_pages(devmem->device, &devmem->pagemap);
> -	if (IS_ERR(result))
> -		return result;
> -	return devmem;
> -}
> -EXPORT_SYMBOL_GPL(hmm_devmem_add_resource);
>  #endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */
> -- 
> 2.20.1