diff options
| author | Oliver O'Halloran <oohall@gmail.com> | 2017-06-28 11:32:33 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-07-02 20:40:27 +1000 |
| commit | b584c2544041707ea041748dbfbb1081289c6cf5 (patch) | |
| tree | d3b0f56dbf44a9194740c402a4f648feb5844cca /arch/powerpc/mm/mem.c | |
| parent | d7d9b612f1b0ac154071bafc02bc9b7b879d7363 (diff) | |
| download | linux-b584c2544041707ea041748dbfbb1081289c6cf5.tar.gz | |
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/mm/mem.c')
| -rw-r--r-- | arch/powerpc/mm/mem.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c index 04f4c9852791f..6f71d259de68f 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; |