Commit bfb34527 authored by Dan Williams's avatar Dan Williams

libnvdimm, pfn: fix memmap reservation size versus 4K alignment

When vmemmap_populate() allocates space for the memmap it does so in 2MB
sized chunks. The libnvdimm-pfn driver incorrectly accounts for this
when the alignment of the device is set to 4K. When this happens we
trigger memory allocation failures in altmap_alloc_block_buf() and
trigger warnings of the form:

 WARNING: CPU: 0 PID: 3376 at arch/x86/mm/init_64.c:656 arch_add_memory+0xe4/0xf0
 [..]
 Call Trace:
  dump_stack+0x86/0xc3
  __warn+0xcb/0xf0
  warn_slowpath_null+0x1d/0x20
  arch_add_memory+0xe4/0xf0
  devm_memremap_pages+0x29b/0x4e0

Fixes: 315c5625 ("libnvdimm, pfn: add 'align' attribute, default to HPAGE_SIZE")
Cc: <stable@vger.kernel.org>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent e471486c
...@@ -627,15 +627,12 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn) ...@@ -627,15 +627,12 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
size = resource_size(&nsio->res); size = resource_size(&nsio->res);
npfns = (size - start_pad - end_trunc - SZ_8K) / SZ_4K; npfns = (size - start_pad - end_trunc - SZ_8K) / SZ_4K;
if (nd_pfn->mode == PFN_MODE_PMEM) { if (nd_pfn->mode == PFN_MODE_PMEM) {
unsigned long memmap_size;
/* /*
* vmemmap_populate_hugepages() allocates the memmap array in * vmemmap_populate_hugepages() allocates the memmap array in
* HPAGE_SIZE chunks. * HPAGE_SIZE chunks.
*/ */
memmap_size = ALIGN(64 * npfns, HPAGE_SIZE); offset = ALIGN(start + SZ_8K + 64 * npfns + dax_label_reserve,
offset = ALIGN(start + SZ_8K + memmap_size + dax_label_reserve, max(nd_pfn->align, HPAGE_SIZE)) - start;
nd_pfn->align) - start;
} else if (nd_pfn->mode == PFN_MODE_RAM) } else if (nd_pfn->mode == PFN_MODE_RAM)
offset = ALIGN(start + SZ_8K + dax_label_reserve, offset = ALIGN(start + SZ_8K + dax_label_reserve,
nd_pfn->align) - start; nd_pfn->align) - start;
......
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