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authorDan Williams <dan.j.williams@intel.com>2020-10-13 16:50:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-13 18:38:28 -0700
commitb7b3c01b191596d27a6980d1a42504f5b607f802 (patch)
tree83c4e9b337bcf8504839d6596d07576168cfd6c7
parenta4574f63edc6f76fb46dcd65d3eb4d5a8e23ba38 (diff)
mm/memremap_pages: support multiple ranges per invocation
In support of device-dax growing the ability to front physically dis-contiguous ranges of memory, update devm_memremap_pages() to track multiple ranges with a single reference counter and devm instance. Convert all [devm_]memremap_pages() users to specify the number of ranges they are mapping in their 'struct dev_pagemap' instance. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Paul Mackerras <paulus@ozlabs.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: David Airlie <airlied@linux.ie> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: "Jérôme Glisse" <jglisse@redhat.co Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hulk Robot <hulkci@huawei.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Yan <yanaijie@huawei.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: "Jérôme Glisse" <jglisse@redhat.com> Cc: Jia He <justin.he@arm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: kernel test robot <lkp@intel.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Will Deacon <will@kernel.org> Link: https://lkml.kernel.org/r/159643103789.4062302.18426128170217903785.stgit@dwillia2-desk3.amr.corp.intel.com Link: https://lkml.kernel.org/r/160106116293.30709.13350662794915396198.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/powerpc/kvm/book3s_hv_uvmem.c1
-rw-r--r--drivers/dax/device.c1
-rw-r--r--drivers/gpu/drm/nouveau/nouveau_dmem.c1
-rw-r--r--drivers/nvdimm/pfn_devs.c1
-rw-r--r--drivers/nvdimm/pmem.c1
-rw-r--r--drivers/pci/p2pdma.c1
-rw-r--r--drivers/xen/unpopulated-alloc.c1
-rw-r--r--include/linux/memremap.h10
-rw-r--r--lib/test_hmm.c1
-rw-r--r--mm/memremap.c258
10 files changed, 166 insertions, 110 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c
index 29ec555055c2..84e5a2dc8be5 100644
--- a/arch/powerpc/kvm/book3s_hv_uvmem.c
+++ b/arch/powerpc/kvm/book3s_hv_uvmem.c
@@ -1172,6 +1172,7 @@ int kvmppc_uvmem_init(void)
kvmppc_uvmem_pgmap.type = MEMORY_DEVICE_PRIVATE;
kvmppc_uvmem_pgmap.range.start = res->start;
kvmppc_uvmem_pgmap.range.end = res->end;
+ kvmppc_uvmem_pgmap.nr_range = 1;
kvmppc_uvmem_pgmap.ops = &kvmppc_uvmem_ops;
/* just one global instance: */
kvmppc_uvmem_pgmap.owner = &kvmppc_uvmem_pgmap;
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index a14448bca83d..5f808617672a 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -417,6 +417,7 @@ int dev_dax_probe(struct dev_dax *dev_dax)
if (!pgmap)
return -ENOMEM;
pgmap->range = *range;
+ pgmap->nr_range = 1;
}
pgmap->type = MEMORY_DEVICE_GENERIC;
addr = devm_memremap_pages(dev, pgmap);
diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c
index 25811ed7e274..a13c6215bba8 100644
--- a/drivers/gpu/drm/nouveau/nouveau_dmem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c
@@ -251,6 +251,7 @@ nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, struct page **ppage)
chunk->pagemap.type = MEMORY_DEVICE_PRIVATE;
chunk->pagemap.range.start = res->start;
chunk->pagemap.range.end = res->end;
+ chunk->pagemap.nr_range = 1;
chunk->pagemap.ops = &nouveau_dmem_pagemap_ops;
chunk->pagemap.owner = drm->dev;
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index 3c4787b92a6a..b499df630d4d 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -693,6 +693,7 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap)
.start = nsio->res.start + start_pad,
.end = nsio->res.end - end_trunc,
};
+ pgmap->nr_range = 1;
if (nd_pfn->mode == PFN_MODE_RAM) {
if (offset < reserve)
return -EINVAL;
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 1f394f44838f..875076b0ea6c 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -441,6 +441,7 @@ static int pmem_attach_disk(struct device *dev,
} else if (pmem_should_map_pages(dev)) {
pmem->pgmap.range.start = res->start;
pmem->pgmap.range.end = res->end;
+ pmem->pgmap.nr_range = 1;
pmem->pgmap.type = MEMORY_DEVICE_FS_DAX;
pmem->pgmap.ops = &fsdax_pagemap_ops;
addr = devm_memremap_pages(dev, &pmem->pgmap);
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 256850513813..9d53c16b7329 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -187,6 +187,7 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size,
pgmap = &p2p_pgmap->pgmap;
pgmap->range.start = pci_resource_start(pdev, bar) + offset;
pgmap->range.end = pgmap->range.start + size - 1;
+ pgmap->nr_range = 1;
pgmap->type = MEMORY_DEVICE_PCI_P2PDMA;
p2p_pgmap->provider = pdev;
diff --git a/drivers/xen/unpopulated-alloc.c b/drivers/xen/unpopulated-alloc.c
index 091b8669eca3..8c512ea550bb 100644
--- a/drivers/xen/unpopulated-alloc.c
+++ b/drivers/xen/unpopulated-alloc.c
@@ -47,6 +47,7 @@ static int fill_list(unsigned int nr_pages)
.start = res->start,
.end = res->end,
};
+ pgmap->nr_range = 1;
pgmap->owner = res;
#ifdef CONFIG_XEN_HAVE_PVMMU
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index d0dd261d87c0..79c49e7f5c30 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -94,7 +94,6 @@ struct dev_pagemap_ops {
/**
* struct dev_pagemap - metadata for ZONE_DEVICE mappings
* @altmap: pre-allocated/reserved memory for vmemmap allocations
- * @range: 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
@@ -104,10 +103,12 @@ struct dev_pagemap_ops {
* @owner: an opaque pointer identifying the entity that manages this
* instance. Used by various helpers to make sure that no
* foreign ZONE_DEVICE memory is accessed.
+ * @nr_range: number of ranges to be mapped
+ * @range: range to be mapped when nr_range == 1
+ * @ranges: array of ranges to be mapped when nr_range > 1
*/
struct dev_pagemap {
struct vmem_altmap altmap;
- struct range range;
struct percpu_ref *ref;
struct percpu_ref internal_ref;
struct completion done;
@@ -115,6 +116,11 @@ struct dev_pagemap {
unsigned int flags;
const struct dev_pagemap_ops *ops;
void *owner;
+ int nr_range;
+ union {
+ struct range range;
+ struct range ranges[0];
+ };
};
static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap)
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index e97ca8ec0bce..c710b4c5714d 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -472,6 +472,7 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice,
devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
devmem->pagemap.range.start = res->start;
devmem->pagemap.range.end = res->end;
+ devmem->pagemap.nr_range = 1;
devmem->pagemap.ops = &dmirror_devmem_ops;
devmem->pagemap.owner = mdevice;
diff --git a/mm/memremap.c b/mm/memremap.c
index d958d348b3ca..532ec3d36ab4 100644
--- a/mm/memremap.c
+++ b/mm/memremap.c
@@ -77,15 +77,19 @@ static void pgmap_array_delete(struct range *range)
synchronize_rcu();
}
-static unsigned long pfn_first(struct dev_pagemap *pgmap)
+static unsigned long pfn_first(struct dev_pagemap *pgmap, int range_id)
{
- return PHYS_PFN(pgmap->range.start) +
- vmem_altmap_offset(pgmap_altmap(pgmap));
+ struct range *range = &pgmap->ranges[range_id];
+ unsigned long pfn = PHYS_PFN(range->start);
+
+ if (range_id)
+ return pfn;
+ return pfn + vmem_altmap_offset(pgmap_altmap(pgmap));
}
-static unsigned long pfn_end(struct dev_pagemap *pgmap)
+static unsigned long pfn_end(struct dev_pagemap *pgmap, int range_id)
{
- const struct range *range = &pgmap->range;
+ const struct range *range = &pgmap->ranges[range_id];
return (range->start + range_len(range)) >> PAGE_SHIFT;
}
@@ -97,8 +101,8 @@ static unsigned long pfn_next(unsigned long pfn)
return pfn + 1;
}
-#define for_each_device_pfn(pfn, map) \
- for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn))
+#define for_each_device_pfn(pfn, map, i) \
+ for (pfn = pfn_first(map, i); pfn < pfn_end(map, i); pfn = pfn_next(pfn))
static void dev_pagemap_kill(struct dev_pagemap *pgmap)
{
@@ -124,20 +128,14 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap)
pgmap->ref = NULL;
}
-void memunmap_pages(struct dev_pagemap *pgmap)
+static void pageunmap_range(struct dev_pagemap *pgmap, int range_id)
{
- struct range *range = &pgmap->range;
+ struct range *range = &pgmap->ranges[range_id];
struct page *first_page;
- unsigned long pfn;
int nid;
- dev_pagemap_kill(pgmap);
- for_each_device_pfn(pfn, pgmap)
- put_page(pfn_to_page(pfn));
- dev_pagemap_cleanup(pgmap);
-
/* make sure to access a memmap that was actually initialized */
- first_page = pfn_to_page(pfn_first(pgmap));
+ first_page = pfn_to_page(pfn_first(pgmap, range_id));
/* pages are dead and unused, undo the arch mapping */
nid = page_to_nid(first_page);
@@ -157,6 +155,22 @@ void memunmap_pages(struct dev_pagemap *pgmap)
untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
pgmap_array_delete(range);
+}
+
+void memunmap_pages(struct dev_pagemap *pgmap)
+{
+ unsigned long pfn;
+ int i;
+
+ dev_pagemap_kill(pgmap);
+ for (i = 0; i < pgmap->nr_range; i++)
+ for_each_device_pfn(pfn, pgmap, i)
+ put_page(pfn_to_page(pfn));
+ dev_pagemap_cleanup(pgmap);
+
+ for (i = 0; i < pgmap->nr_range; i++)
+ pageunmap_range(pgmap, i);
+
WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n");
devmap_managed_enable_put();
}
@@ -175,96 +189,29 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref)
complete(&pgmap->done);
}
-/*
- * 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 *memremap_pages(struct dev_pagemap *pgmap, int nid)
+static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
+ int range_id, int nid)
{
- struct range *range = &pgmap->range;
+ struct range *range = &pgmap->ranges[range_id];
struct dev_pagemap *conflict_pgmap;
- struct mhp_params params = {
- /*
- * We do not want any optional features only our own memmap
- */
- .altmap = pgmap_altmap(pgmap),
- .pgprot = PAGE_KERNEL,
- };
int error, is_ram;
- bool need_devmap_managed = true;
- switch (pgmap->type) {
- case MEMORY_DEVICE_PRIVATE:
- if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) {
- WARN(1, "Device private memory not supported\n");
- return ERR_PTR(-EINVAL);
- }
- if (!pgmap->ops || !pgmap->ops->migrate_to_ram) {
- WARN(1, "Missing migrate_to_ram method\n");
- return ERR_PTR(-EINVAL);
- }
- if (!pgmap->owner) {
- WARN(1, "Missing owner\n");
- return ERR_PTR(-EINVAL);
- }
- break;
- case MEMORY_DEVICE_FS_DAX:
- if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||
- IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
- WARN(1, "File system DAX not supported\n");
- return ERR_PTR(-EINVAL);
- }
- break;
- case MEMORY_DEVICE_GENERIC:
- need_devmap_managed = false;
- break;
- case MEMORY_DEVICE_PCI_P2PDMA:
- params.pgprot = pgprot_noncached(params.pgprot);
- need_devmap_managed = false;
- break;
- default:
- WARN(1, "Invalid pgmap type %d\n", pgmap->type);
- break;
- }
-
- 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) {
- error = devmap_managed_enable_get(pgmap);
- if (error)
- return ERR_PTR(error);
- }
+ if (WARN_ONCE(pgmap_altmap(pgmap) && range_id > 0,
+ "altmap not supported for multiple ranges\n"))
+ return -EINVAL;
conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->start), NULL);
if (conflict_pgmap) {
WARN(1, "Conflicting mapping in same section\n");
put_dev_pagemap(conflict_pgmap);
- error = -ENOMEM;
- goto err_array;
+ return -ENOMEM;
}
conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->end), NULL);
if (conflict_pgmap) {
WARN(1, "Conflicting mapping in same section\n");
put_dev_pagemap(conflict_pgmap);
- error = -ENOMEM;
- goto err_array;
+ return -ENOMEM;
}
is_ram = region_intersects(range->start, range_len(range),
@@ -274,19 +221,18 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
WARN_ONCE(1, "attempted on %s region %#llx-%#llx\n",
is_ram == REGION_MIXED ? "mixed" : "ram",
range->start, range->end);
- error = -ENXIO;
- goto err_array;
+ return -ENXIO;
}
error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(range->start),
PHYS_PFN(range->end), pgmap, GFP_KERNEL));
if (error)
- goto err_array;
+ return error;
if (nid < 0)
nid = numa_mem_id();
- error = track_pfn_remap(NULL, &params.pgprot, PHYS_PFN(range->start), 0,
+ error = track_pfn_remap(NULL, &params->pgprot, PHYS_PFN(range->start), 0,
range_len(range));
if (error)
goto err_pfn_remap;
@@ -306,7 +252,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
*/
if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
error = add_pages(nid, PHYS_PFN(range->start),
- PHYS_PFN(range_len(range)), &params);
+ PHYS_PFN(range_len(range)), params);
} else {
error = kasan_add_zero_shadow(__va(range->start), range_len(range));
if (error) {
@@ -315,7 +261,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
}
error = arch_add_memory(nid, range->start, range_len(range),
- &params);
+ params);
}
if (!error) {
@@ -323,7 +269,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
move_pfn_range_to_zone(zone, PHYS_PFN(range->start),
- PHYS_PFN(range_len(range)), params.altmap);
+ PHYS_PFN(range_len(range)), params->altmap);
}
mem_hotplug_done();
@@ -337,20 +283,116 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid)
memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
PHYS_PFN(range->start),
PHYS_PFN(range_len(range)), pgmap);
- percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap));
- return __va(range->start);
+ percpu_ref_get_many(pgmap->ref, pfn_end(pgmap, range_id)
+ - pfn_first(pgmap, range_id));
+ return 0;
- err_add_memory:
+err_add_memory:
kasan_remove_zero_shadow(__va(range->start), range_len(range));
- err_kasan:
+err_kasan:
untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range));
- err_pfn_remap:
+err_pfn_remap:
pgmap_array_delete(range);
- err_array:
- dev_pagemap_kill(pgmap);
- dev_pagemap_cleanup(pgmap);
- devmap_managed_enable_put();
- return ERR_PTR(error);
+ return error;
+}
+
+
+/*
+ * 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 *memremap_pages(struct dev_pagemap *pgmap, int nid)
+{
+ struct mhp_params params = {
+ .altmap = pgmap_altmap(pgmap),
+ .pgprot = PAGE_KERNEL,
+ };
+ const int nr_range = pgmap->nr_range;
+ bool need_devmap_managed = true;
+ int error, i;
+
+ if (WARN_ONCE(!nr_range, "nr_range must be specified\n"))
+ return ERR_PTR(-EINVAL);
+
+ switch (pgmap->type) {
+ case MEMORY_DEVICE_PRIVATE:
+ if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) {
+ WARN(1, "Device private memory not supported\n");
+ return ERR_PTR(-EINVAL);
+ }
+ if (!pgmap->ops || !pgmap->ops->migrate_to_ram) {
+ WARN(1, "Missing migrate_to_ram method\n");
+ return ERR_PTR(-EINVAL);
+ }
+ if (!pgmap->owner) {
+ WARN(1, "Missing owner\n");
+ return ERR_PTR(-EINVAL);
+ }
+ break;
+ case MEMORY_DEVICE_FS_DAX:
+ if (!IS_ENABLED(CONFIG_ZONE_DEVICE) ||
+ IS_ENABLED(CONFIG_FS_DAX_LIMITED)) {
+ WARN(1, "File system DAX not supported\n");
+ return ERR_PTR(-EINVAL);
+ }
+ break;
+ case MEMORY_DEVICE_GENERIC:
+ need_devmap_managed = false;
+ break;
+ case MEMORY_DEVICE_PCI_P2PDMA:
+ params.pgprot = pgprot_noncached(params.pgprot);
+ need_devmap_managed = false;
+ break;
+ default:
+ WARN(1, "Invalid pgmap type %d\n", pgmap->type);
+ break;
+ }
+
+ 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) {
+ error = devmap_managed_enable_get(pgmap);
+ if (error)
+ return ERR_PTR(error);
+ }
+
+ /*
+ * Clear the pgmap nr_range as it will be incremented for each
+ * successfully processed range. This communicates how many
+ * regions to unwind in the abort case.
+ */
+ pgmap->nr_range = 0;
+ error = 0;
+ for (i = 0; i < nr_range; i++) {
+ error = pagemap_range(pgmap, &params, i, nid);
+ if (error)
+ break;
+ pgmap->nr_range++;
+ }
+
+ if (i < nr_range) {
+ memunmap_pages(pgmap);
+ pgmap->nr_range = nr_range;
+ return ERR_PTR(error);
+ }
+
+ return __va(pgmap->ranges[0].start);
}
EXPORT_SYMBOL_GPL(memremap_pages);