From: Christoph Hellwig <hch@lst.de>
To: "Dan Williams" <dan.j.williams@intel.com>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Jason Gunthorpe" <jgg@mellanox.com>,
"Ben Skeggs" <bskeggs@redhat.com>
Cc: linux-mm@kvack.org, nouveau@lists.freedesktop.org,
dri-devel@lists.freedesktop.org, linux-nvdimm@lists.01.org,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 15/25] memremap: provide an optional internal refcount in struct dev_pagemap
Date: Wed, 26 Jun 2019 14:27:14 +0200 [thread overview]
Message-ID: <20190626122724.13313-16-hch@lst.de> (raw)
In-Reply-To: <20190626122724.13313-1-hch@lst.de>
Provide an internal refcounting logic if no ->ref field is provided
in the pagemap passed into devm_memremap_pages so that callers don't
have to reinvent it poorly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/linux/memremap.h | 4 ++
kernel/memremap.c | 64 ++++++++++++++++++++++++-------
tools/testing/nvdimm/test/iomap.c | 58 ++++++++++++++++++++++------
3 files changed, 101 insertions(+), 25 deletions(-)
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index e25685b878e9..f8a5b2a19945 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -95,6 +95,8 @@ struct dev_pagemap_ops {
* @altmap: pre-allocated/reserved memory for vmemmap allocations
* @res: physical address range covered by @ref
* @ref: reference count that pins the devm_memremap_pages() mapping
+ * @internal_ref: internal reference if @ref is not provided by the caller
+ * @done: completion for @internal_ref
* @dev: host device of the mapping for debug
* @data: private data pointer for page_free()
* @type: memory type: see MEMORY_* in memory_hotplug.h
@@ -105,6 +107,8 @@ struct dev_pagemap {
struct vmem_altmap altmap;
struct resource res;
struct percpu_ref *ref;
+ struct percpu_ref internal_ref;
+ struct completion done;
struct device *dev;
enum memory_type type;
unsigned int flags;
diff --git a/kernel/memremap.c b/kernel/memremap.c
index eee490e7d7e1..bea6f887adad 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -29,7 +29,7 @@ static void devmap_managed_enable_put(void *data)
static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgmap)
{
- if (!pgmap->ops->page_free) {
+ if (!pgmap->ops || !pgmap->ops->page_free) {
WARN(1, "Missing page_free method\n");
return -EINVAL;
}
@@ -75,6 +75,24 @@ static unsigned long pfn_next(unsigned long pfn)
#define for_each_device_pfn(pfn, map) \
for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn))
+static void dev_pagemap_kill(struct dev_pagemap *pgmap)
+{
+ if (pgmap->ops && pgmap->ops->kill)
+ pgmap->ops->kill(pgmap);
+ else
+ percpu_ref_kill(pgmap->ref);
+}
+
+static void dev_pagemap_cleanup(struct dev_pagemap *pgmap)
+{
+ if (pgmap->ops && pgmap->ops->cleanup) {
+ pgmap->ops->cleanup(pgmap);
+ } else {
+ wait_for_completion(&pgmap->done);
+ percpu_ref_exit(pgmap->ref);
+ }
+}
+
static void devm_memremap_pages_release(void *data)
{
struct dev_pagemap *pgmap = data;
@@ -84,10 +102,10 @@ static void devm_memremap_pages_release(void *data)
unsigned long pfn;
int nid;
- pgmap->ops->kill(pgmap);
+ dev_pagemap_kill(pgmap);
for_each_device_pfn(pfn, pgmap)
put_page(pfn_to_page(pfn));
- pgmap->ops->cleanup(pgmap);
+ dev_pagemap_cleanup(pgmap);
/* pages are dead and unused, undo the arch mapping */
align_start = res->start & ~(SECTION_SIZE - 1);
@@ -114,20 +132,29 @@ static void devm_memremap_pages_release(void *data)
"%s: failed to free all reserved pages\n", __func__);
}
+static void dev_pagemap_percpu_release(struct percpu_ref *ref)
+{
+ struct dev_pagemap *pgmap =
+ container_of(ref, struct dev_pagemap, internal_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, ref and type and ops members of @pgmap must be
- * initialized by the caller before passing it to this function
+ * 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/ pgmap->ref must be 'live' on entry and will be killed and reaped
- * at devm_memremap_pages_release() time, or if this routine fails.
+ * 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
@@ -175,10 +202,21 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
break;
}
- if (!pgmap->ref || !pgmap->ops || !pgmap->ops->kill ||
- !pgmap->ops->cleanup) {
- WARN(1, "Missing reference count teardown definition\n");
- return ERR_PTR(-EINVAL);
+ if (!pgmap->ref) {
+ if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup))
+ return ERR_PTR(-EINVAL);
+
+ init_completion(&pgmap->done);
+ error = percpu_ref_init(&pgmap->internal_ref,
+ dev_pagemap_percpu_release, 0, GFP_KERNEL);
+ if (error)
+ return ERR_PTR(error);
+ pgmap->ref = &pgmap->internal_ref;
+ } else {
+ if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) {
+ WARN(1, "Missing reference count teardown definition\n");
+ return ERR_PTR(-EINVAL);
+ }
}
if (need_devmap_managed) {
@@ -296,8 +334,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
err_pfn_remap:
pgmap_array_delete(res);
err_array:
- pgmap->ops->kill(pgmap);
- pgmap->ops->cleanup(pgmap);
+ dev_pagemap_kill(pgmap);
+ dev_pagemap_cleanup(pgmap);
return ERR_PTR(error);
}
EXPORT_SYMBOL_GPL(devm_memremap_pages);
diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c
index 82f901569e06..cd040b5abffe 100644
--- a/tools/testing/nvdimm/test/iomap.c
+++ b/tools/testing/nvdimm/test/iomap.c
@@ -100,26 +100,60 @@ static void nfit_test_kill(void *_pgmap)
{
struct dev_pagemap *pgmap = _pgmap;
- WARN_ON(!pgmap || !pgmap->ref || !pgmap->ops || !pgmap->ops->kill ||
- !pgmap->ops->cleanup);
- pgmap->ops->kill(pgmap);
- pgmap->ops->cleanup(pgmap);
+ WARN_ON(!pgmap || !pgmap->ref);
+
+ if (pgmap->ops && pgmap->ops->kill)
+ pgmap->ops->kill(pgmap);
+ else
+ percpu_ref_kill(pgmap->ref);
+
+ if (pgmap->ops && pgmap->ops->cleanup) {
+ pgmap->ops->cleanup(pgmap);
+ } else {
+ wait_for_completion(&pgmap->done);
+ percpu_ref_exit(pgmap->ref);
+ }
+}
+
+static void dev_pagemap_percpu_release(struct percpu_ref *ref)
+{
+ struct dev_pagemap *pgmap =
+ container_of(ref, struct dev_pagemap, internal_ref);
+
+ complete(&pgmap->done);
}
void *__wrap_devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
+ int error;
resource_size_t offset = pgmap->res.start;
struct nfit_test_resource *nfit_res = get_nfit_res(offset);
- if (nfit_res) {
- int rc;
-
- rc = devm_add_action_or_reset(dev, nfit_test_kill, pgmap);
- if (rc)
- return ERR_PTR(rc);
- return nfit_res->buf + offset - nfit_res->res.start;
+ if (!nfit_res)
+ return devm_memremap_pages(dev, pgmap);
+
+ pgmap->dev = dev;
+ if (!pgmap->ref) {
+ if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup))
+ return ERR_PTR(-EINVAL);
+
+ init_completion(&pgmap->done);
+ error = percpu_ref_init(&pgmap->internal_ref,
+ dev_pagemap_percpu_release, 0, GFP_KERNEL);
+ if (error)
+ return ERR_PTR(error);
+ pgmap->ref = &pgmap->internal_ref;
+ } else {
+ if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) {
+ WARN(1, "Missing reference count teardown definition\n");
+ return ERR_PTR(-EINVAL);
+ }
}
- return devm_memremap_pages(dev, pgmap);
+
+ error = devm_add_action_or_reset(dev, nfit_test_kill, pgmap);
+ if (error)
+ return ERR_PTR(error);
+ return nfit_res->buf + offset - nfit_res->res.start;
}
EXPORT_SYMBOL_GPL(__wrap_devm_memremap_pages);
--
2.20.1
next prev parent reply other threads:[~2019-06-26 12:28 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-26 12:26 dev_pagemap related cleanups v3 Christoph Hellwig
2019-06-26 12:27 ` [PATCH 01/25] mm: remove the unused ARCH_HAS_HMM_DEVICE Kconfig option Christoph Hellwig
2019-06-26 12:27 ` [PATCH 02/25] mm: remove the struct hmm_device infrastructure Christoph Hellwig
2019-06-26 12:27 ` [PATCH 03/25] mm: remove hmm_devmem_add_resource Christoph Hellwig
2019-06-27 16:18 ` Jason Gunthorpe
2019-06-27 16:54 ` Christoph Hellwig
2019-06-26 12:27 ` [PATCH 04/25] mm: remove MEMORY_DEVICE_PUBLIC support Christoph Hellwig
2019-06-26 16:00 ` Dan Williams
2019-06-26 17:14 ` Ira Weiny
2019-06-26 18:49 ` Ira Weiny
2019-06-26 12:27 ` [PATCH 05/25] mm: don't clear ->mapping in hmm_devmem_free Christoph Hellwig
2019-06-26 12:27 ` [PATCH 06/25] mm: export alloc_pages_vma Christoph Hellwig
2019-06-26 12:36 ` Michal Hocko
2019-06-26 12:27 ` [PATCH 07/25] mm: factor out a devm_request_free_mem_region helper Christoph Hellwig
2019-06-26 12:27 ` [PATCH 08/25] memremap: validate the pagemap type passed to devm_memremap_pages Christoph Hellwig
2019-06-26 18:01 ` Ira Weiny
2019-06-26 12:27 ` [PATCH 09/25] memremap: move dev_pagemap callbacks into a separate structure Christoph Hellwig
2019-06-26 12:27 ` [PATCH 10/25] memremap: pass a struct dev_pagemap to ->kill and ->cleanup Christoph Hellwig
2019-06-26 12:27 ` [PATCH 11/25] memremap: lift the devmap_enable manipulation into devm_memremap_pages Christoph Hellwig
2019-06-26 19:04 ` Ira Weiny
2019-06-27 8:50 ` Christoph Hellwig
2019-06-26 12:27 ` [PATCH 12/25] memremap: add a migrate_to_ram method to struct dev_pagemap_ops Christoph Hellwig
2019-06-27 16:29 ` Jason Gunthorpe
2019-06-27 16:53 ` Christoph Hellwig
2019-06-26 12:27 ` [PATCH 13/25] memremap: remove the data field in struct dev_pagemap Christoph Hellwig
2019-06-26 12:27 ` [PATCH 14/25] memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag Christoph Hellwig
2019-06-26 21:13 ` Ira Weiny
2019-06-26 12:27 ` Christoph Hellwig [this message]
2019-06-26 21:47 ` [PATCH 15/25] memremap: provide an optional internal refcount in struct dev_pagemap Ira Weiny
2019-06-27 8:51 ` Christoph Hellwig
2019-06-26 12:27 ` [PATCH 16/25] device-dax: use the dev_pagemap internal refcount Christoph Hellwig
2019-06-26 21:48 ` Ira Weiny
2019-06-28 15:38 ` Jason Gunthorpe
2019-06-28 16:27 ` Dan Williams
2019-06-28 17:02 ` Jason Gunthorpe
2019-06-28 17:08 ` Dan Williams
2019-06-28 17:10 ` Dan Williams
2019-06-28 18:29 ` Jason Gunthorpe
2019-06-28 18:44 ` Dan Williams
2019-06-28 18:51 ` Christoph Hellwig
2019-06-28 18:59 ` Dan Williams
2019-06-28 19:02 ` Christoph Hellwig
2019-06-28 19:14 ` Dan Williams
2019-07-02 22:35 ` Andrew Morton
2019-06-26 12:27 ` [PATCH 17/25] PCI/P2PDMA: " Christoph Hellwig
2019-06-26 21:49 ` Ira Weiny
2019-06-27 18:49 ` Logan Gunthorpe
2019-06-26 12:27 ` [PATCH 18/25] nouveau: use alloc_page_vma directly Christoph Hellwig
2019-06-26 12:27 ` [PATCH 19/25] nouveau: use devm_memremap_pages directly Christoph Hellwig
2019-06-26 12:27 ` [PATCH 20/25] mm: remove hmm_vma_alloc_locked_page Christoph Hellwig
2019-06-27 16:26 ` Jason Gunthorpe
2019-06-26 12:27 ` [PATCH 21/25] mm: remove hmm_devmem_add Christoph Hellwig
2019-06-26 12:27 ` [PATCH 22/25] mm: simplify ZONE_DEVICE page private data Christoph Hellwig
2019-06-26 12:27 ` [PATCH 23/25] mm: sort out the DEVICE_PRIVATE Kconfig mess Christoph Hellwig
2019-06-26 21:36 ` Ira Weiny
2019-06-26 12:27 ` [PATCH 24/25] mm: remove the HMM config option Christoph Hellwig
2019-06-26 21:38 ` Ira Weiny
2019-06-27 16:29 ` Jason Gunthorpe
2019-06-26 12:27 ` [PATCH 25/25] mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR Christoph Hellwig
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