[PATCH v10 11/13] mm/devm_memremap_pages: Enable sub-section remap

Dan Williams
2019-06-19T06:06:55Z

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).

Cc: Michal Hocko <mhocko@suse.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
kernel/memremap.c | 61 +++++++++++++++++++++--------------------------------
1 file changed, 24 insertions(+), 37 deletions(-)

diff --git a/kernel/memremap.c b/kernel/memremap.c
index 57980ed4e571..a0e5f6b91b04 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -58,7 +58,7 @@ static unsigned long pfn_first(struct dev_pagemap *pgmap)
struct vmem_altmap *altmap = &pgmap->altmap;
unsigned long pfn;

- pfn = res->start >> PAGE_SHIFT;
+ pfn = PHYS_PFN(res->start);
if (pgmap->altmap_valid)
pfn += vmem_altmap_offset(altmap);
return pfn;
@@ -86,7 +86,6 @@ 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;

@@ -96,25 +95,21 @@ static void devm_memremap_pages_release(void *data)
pgmap->cleanup(pgmap->ref);

/* pages are dead and unused, undo the arch mapping */
- align_start = res->start & ~(PA_SECTION_SIZE - 1);
- align_size = ALIGN(res->start + resource_size(res), PA_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_valid ? &pgmap->altmap : NULL);
- 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__);
@@ -141,16 +136,13 @@ static void devm_memremap_pages_release(void *data)
*/
void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
{
- resource_size_t align_start, align_size, align_end;
- struct vmem_altmap *altmap = pgmap->altmap_valid ?
- &pgmap->altmap : NULL;
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 = altmap,
+ .altmap = pgmap->altmap_valid ? &pgmap->altmap : NULL,
};
pgprot_t pgprot = PAGE_KERNEL;
int error, nid, is_ram;
@@ -160,12 +152,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
return ERR_PTR(-EINVAL);
}

- align_start = res->start & ~(PA_SECTION_SIZE - 1);
- align_size = ALIGN(res->start + resource_size(res), PA_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);
@@ -173,7 +160,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
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);
@@ -181,7 +168,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
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) {
@@ -202,8 +189,8 @@ 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;

@@ -221,25 +208,25 @@ 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,
- &restrictions);
+ 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, altmap);
+ move_pfn_range_to_zone(zone, PHYS_PFN(res->start),
+ PHYS_PFN(resource_size(res)), restrictions.altmap);
}

mem_hotplug_done();
@@ -251,8 +238,8 @@ 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,
@@ -263,9 +250,9 @@ 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);