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mm/devm_memremap_pages: enable sub-section remap
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Teach devm_memremap_pages() about the new sub-section capabilities of
arch_{add,remove}_memory().  Effectively, just replace all usage of
align_start, align_end, and align_size with res->start, res->end, and
resource_size(res).  The existing sanity check will still make sure that
the two separate remap attempts do not collide within a sub-section (2MB
on x86).

Link: http://lkml.kernel.org/r/156092355542.979959.10060071713397030576.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <[email protected]>
Tested-by: Aneesh Kumar K.V <[email protected]>	[ppc64]
Cc: Michal Hocko <[email protected]>
Cc: Toshi Kani <[email protected]>
Cc: Jérôme Glisse <[email protected]>
Cc: Logan Gunthorpe <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pavel Tatashin <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Jane Chu <[email protected]>
Cc: Jeff Moyer <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Wei Yang <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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@djbw @torvalds
djbw authored and torvalds committed Jul 19, 2019
1 parent a065340 commit 7cc7867
Showing 1 changed file with 23 additions and 34 deletions.
57 changes: 23 additions & 34 deletions kernel/memremap.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -54,7 +54,7 @@ static void pgmap_array_delete(struct resource *res)

static unsigned long pfn_first(struct dev_pagemap *pgmap)
{
return (pgmap->res.start >> PAGE_SHIFT) +
return PHYS_PFN(pgmap->res.start) +
vmem_altmap_offset(pgmap_altmap(pgmap));
}

Expand Down Expand Up @@ -98,7 +98,6 @@ static void devm_memremap_pages_release(void *data)
struct dev_pagemap *pgmap = data;
struct device *dev = pgmap->dev;
struct resource *res = &pgmap->res;
resource_size_t align_start, align_size;
unsigned long pfn;
int nid;

Expand All @@ -108,25 +107,21 @@ static void devm_memremap_pages_release(void *data)
dev_pagemap_cleanup(pgmap);

/* pages are dead and unused, undo the arch mapping */
align_start = res->start & ~(SECTION_SIZE - 1);
align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
- align_start;

nid = page_to_nid(pfn_to_page(align_start >> PAGE_SHIFT));
nid = page_to_nid(pfn_to_page(PHYS_PFN(res->start)));

mem_hotplug_begin();
if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
pfn = align_start >> PAGE_SHIFT;
pfn = PHYS_PFN(res->start);
__remove_pages(page_zone(pfn_to_page(pfn)), pfn,
align_size >> PAGE_SHIFT, NULL);
PHYS_PFN(resource_size(res)), NULL);
} else {
arch_remove_memory(nid, align_start, align_size,
arch_remove_memory(nid, res->start, resource_size(res),
pgmap_altmap(pgmap));
kasan_remove_zero_shadow(__va(align_start), align_size);
kasan_remove_zero_shadow(__va(res->start), resource_size(res));
}
mem_hotplug_done();

untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
pgmap_array_delete(res);
dev_WARN_ONCE(dev, pgmap->altmap.alloc,
"%s: failed to free all reserved pages\n", __func__);
Expand Down Expand Up @@ -162,13 +157,12 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref)
*/
void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
resource_size_t align_start, align_size, align_end;
struct resource *res = &pgmap->res;
struct dev_pagemap *conflict_pgmap;
struct mhp_restrictions restrictions = {
/*
* We do not want any optional features only our own memmap
*/
*/
.altmap = pgmap_altmap(pgmap),
};
pgprot_t pgprot = PAGE_KERNEL;
Expand Down Expand Up @@ -225,28 +219,23 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
return ERR_PTR(error);
}

align_start = res->start & ~(SECTION_SIZE - 1);
align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE)
- align_start;
align_end = align_start + align_size - 1;

conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_start), NULL);
conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->start), NULL);
if (conflict_pgmap) {
dev_WARN(dev, "Conflicting mapping in same section\n");
put_dev_pagemap(conflict_pgmap);
error = -ENOMEM;
goto err_array;
}

conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_end), NULL);
conflict_pgmap = get_dev_pagemap(PHYS_PFN(res->end), NULL);
if (conflict_pgmap) {
dev_WARN(dev, "Conflicting mapping in same section\n");
put_dev_pagemap(conflict_pgmap);
error = -ENOMEM;
goto err_array;
}

is_ram = region_intersects(align_start, align_size,
is_ram = region_intersects(res->start, resource_size(res),
IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE);

if (is_ram != REGION_DISJOINT) {
Expand All @@ -267,8 +256,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
if (nid < 0)
nid = numa_mem_id();

error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(align_start), 0,
align_size);
error = track_pfn_remap(NULL, &pgprot, PHYS_PFN(res->start), 0,
resource_size(res));
if (error)
goto err_pfn_remap;

Expand All @@ -286,25 +275,25 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
* arch_add_memory().
*/
if (pgmap->type == MEMORY_DEVICE_PRIVATE) {
error = add_pages(nid, align_start >> PAGE_SHIFT,
align_size >> PAGE_SHIFT, &restrictions);
error = add_pages(nid, PHYS_PFN(res->start),
PHYS_PFN(resource_size(res)), &restrictions);
} else {
error = kasan_add_zero_shadow(__va(align_start), align_size);
error = kasan_add_zero_shadow(__va(res->start), resource_size(res));
if (error) {
mem_hotplug_done();
goto err_kasan;
}

error = arch_add_memory(nid, align_start, align_size,
error = arch_add_memory(nid, res->start, resource_size(res),
&restrictions);
}

if (!error) {
struct zone *zone;

zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT,
align_size >> PAGE_SHIFT, pgmap_altmap(pgmap));
move_pfn_range_to_zone(zone, PHYS_PFN(res->start),
PHYS_PFN(resource_size(res)), restrictions.altmap);
}

mem_hotplug_done();
Expand All @@ -316,8 +305,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
* to allow us to do the work while not holding the hotplug lock.
*/
memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE],
align_start >> PAGE_SHIFT,
align_size >> PAGE_SHIFT, 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,
Expand All @@ -328,9 +317,9 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
return __va(res->start);

err_add_memory:
kasan_remove_zero_shadow(__va(align_start), align_size);
kasan_remove_zero_shadow(__va(res->start), resource_size(res));
err_kasan:
untrack_pfn(NULL, PHYS_PFN(align_start), align_size);
untrack_pfn(NULL, PHYS_PFN(res->start), resource_size(res));
err_pfn_remap:
pgmap_array_delete(res);
err_array:
Expand Down

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