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authorOliver O'Halloran2017-06-28 03:32:33 +0200
committerMichael Ellerman2017-07-02 12:40:27 +0200
commitb584c2544041707ea041748dbfbb1081289c6cf5 (patch)
treed3b0f56dbf44a9194740c402a4f648feb5844cca /arch/powerpc
parentpowerpc/vmemmap: Reshuffle vmemmap_free() (diff)
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powerpc/vmemmap: Add altmap support
Adds support to powerpc for the altmap feature of ZONE_DEVICE memory. An altmap is a driver provided region that is used to provide the backing storage for the struct pages of ZONE_DEVICE memory. In situations where large amount of ZONE_DEVICE memory is being added to the system the altmap reduces pressure on main system memory by allowing the mm/ metadata to be stored on the device itself rather in main memory. Reviewed-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/mm/init_64.c15
-rw-r--r--arch/powerpc/mm/mem.c16
2 files changed, 26 insertions, 5 deletions
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index f855a2442c97..5b4c25d12ff3 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -44,6 +44,7 @@
#include <linux/slab.h>
#include <linux/of_fdt.h>
#include <linux/libfdt.h>
+#include <linux/memremap.h>
#include <asm/pgalloc.h>
#include <asm/page.h>
@@ -192,13 +193,17 @@ int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node)
pr_debug("vmemmap_populate %lx..%lx, node %d\n", start, end, node);
for (; start < end; start += page_size) {
+ struct vmem_altmap *altmap;
void *p;
int rc;
if (vmemmap_populated(start, page_size))
continue;
- p = vmemmap_alloc_block(page_size, node);
+ /* altmap lookups only work at section boundaries */
+ altmap = to_vmem_altmap(SECTION_ALIGN_DOWN(start));
+
+ p = __vmemmap_alloc_block_buf(page_size, node, altmap);
if (!p)
return -ENOMEM;
@@ -263,6 +268,8 @@ void __ref vmemmap_free(unsigned long start, unsigned long end)
for (; start < end; start += page_size) {
unsigned long nr_pages, addr;
+ struct vmem_altmap *altmap;
+ struct page *section_base;
struct page *page;
/*
@@ -278,9 +285,13 @@ void __ref vmemmap_free(unsigned long start, unsigned long end)
continue;
page = pfn_to_page(addr >> PAGE_SHIFT);
+ section_base = pfn_to_page(vmemmap_section_start(start));
nr_pages = 1 << page_order;
- if (PageReserved(page)) {
+ altmap = to_vmem_altmap((unsigned long) section_base);
+ if (altmap) {
+ vmem_altmap_free(altmap, nr_pages);
+ } else if (PageReserved(page)) {
/* allocated from bootmem */
if (page_size < PAGE_SIZE) {
/*
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 04f4c9852791..6f71d259de68 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -36,6 +36,7 @@
#include <linux/hugetlb.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
+#include <linux/memremap.h>
#include <asm/pgalloc.h>
#include <asm/prom.h>
@@ -159,11 +160,20 @@ int arch_remove_memory(u64 start, u64 size)
{
unsigned long start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
- struct zone *zone;
+ struct vmem_altmap *altmap;
+ struct page *page;
int ret;
- zone = page_zone(pfn_to_page(start_pfn));
- ret = __remove_pages(zone, start_pfn, nr_pages);
+ /*
+ * If we have an altmap then we need to skip over any reserved PFNs
+ * when querying the zone.
+ */
+ page = pfn_to_page(start_pfn);
+ altmap = to_vmem_altmap((unsigned long) page);
+ if (altmap)
+ page += vmem_altmap_offset(altmap);
+
+ ret = __remove_pages(page_zone(page), start_pfn, nr_pages);
if (ret)
return ret;