Linux-mm Archive on lore.kernel.org
 help / color / Atom feed
From: Christoph Hellwig <hch@lst.de>
To: Dan Williams <dan.j.williams@intel.com>,
	Jason Gunthorpe <jgg@mellanox.com>
Cc: Bharata B Rao <bharata@linux.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	linux-nvdimm@lists.01.org
Subject: [PATCH 4/4] memremap: provide a not device managed memremap_pages
Date: Fri, 16 Aug 2019 08:54:34 +0200
Message-ID: <20190816065434.2129-5-hch@lst.de> (raw)
In-Reply-To: <20190816065434.2129-1-hch@lst.de>

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.  Note that this function is
not exported, and doesn't have a cleanup routine associated with it to
discourage use from more driver like users.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/memremap.h |  2 +
 mm/memremap.c            | 84 +++++++++++++++++++++++++---------------
 2 files changed, 54 insertions(+), 32 deletions(-)

diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index 8f0013e18e14..fb2a0bd826b9 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -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,
diff --git a/mm/memremap.c b/mm/memremap.c
index 4e11da4ecab9..9e163fe367ae 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -102,9 +102,8 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap)
 		pgmap->ref = NULL;
 }
 
-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;
@@ -134,6 +133,12 @@ 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)
 {
@@ -143,27 +148,12 @@ 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;
@@ -174,7 +164,7 @@ 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) {
@@ -229,7 +219,7 @@ 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;
@@ -237,7 +227,7 @@ 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;
@@ -258,7 +248,6 @@ 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();
 
@@ -314,12 +303,6 @@ 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:
@@ -334,6 +317,43 @@ 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)
-- 
2.20.1



  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-16  6:54 add a not device managed memremap_pages v2 Christoph Hellwig
2019-08-16  6:54 ` [PATCH 1/4] resource: add a not device managed request_free_mem_region variant Christoph Hellwig
2019-08-16 21:01   ` Andrew Morton
2019-08-18  9:03     ` Christoph Hellwig
2019-08-16  6:54 ` [PATCH 2/4] memremap: remove the dev field in struct dev_pagemap Christoph Hellwig
2019-08-16  6:54 ` [PATCH 3/4] memremap: don't use a separate devm action for devmap_managed_enable_get Christoph Hellwig
2019-08-16  6:54 ` Christoph Hellwig [this message]
2019-08-16 21:00   ` [PATCH 4/4] memremap: provide a not device managed memremap_pages Andrew Morton
2019-08-18  9:04     ` Christoph Hellwig
2019-08-16 10:48 ` add a not device managed memremap_pages v2 Bharata B Rao
2019-08-16 12:34 ` Jason Gunthorpe
2019-08-16 12:36   ` Christoph Hellwig
2019-08-16 12:40     ` Jason Gunthorpe
2019-08-16 23:59 ` Ira Weiny
2019-08-18  9:05 add a not device managed memremap_pages v3 Christoph Hellwig
2019-08-18  9:05 ` [PATCH 4/4] memremap: provide a not device managed memremap_pages Christoph Hellwig
2019-08-20  2:24   ` Dan Williams

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190816065434.2129-5-hch@lst.de \
    --to=hch@lst.de \
    --cc=akpm@linux-foundation.org \
    --cc=bharata@linux.ibm.com \
    --cc=dan.j.williams@intel.com \
    --cc=jgg@mellanox.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-nvdimm@lists.01.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-mm Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-mm/0 linux-mm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-mm linux-mm/ https://lore.kernel.org/linux-mm \
		linux-mm@kvack.org linux-mm@archiver.kernel.org
	public-inbox-index linux-mm


Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kvack.linux-mm


AGPL code for this site: git clone https://public-inbox.org/ public-inbox