mm/devm_memremap_pages: enable sub-section remap

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 <dan.j.williams@intel.com>
Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>	[ppc64]
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>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richardw.yang@linux.intel.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/memremap.c b/kernel/memremap.c
index bea6f88..6ee03a8 100644 (file)
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -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));
 }
 
@@ -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;
 
@@ -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__);
@@ -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;
@@ -225,12 +219,7 @@ 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);
@@ -238,7 +227,7 @@ 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);
@@ -246,7 +235,7 @@ 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) {
@@ -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;
 
@@ -286,16 +275,16 @@ 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);
        }
 
@@ -303,8 +292,8 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap)
                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();
@@ -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,
@@ -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: