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ACPI: Change NFIT driver to insert new resource

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ACPI 6 defines persistent memory (PMEM) ranges in multiple
firmware interfaces, e820, EFI, and ACPI NFIT table.  This EFI
change, however, leads to hit a bug in the grub bootloader, which
treats EFI_PERSISTENT_MEMORY type as regular memory and corrupts
stored user data [1].

Therefore, BIOS may set generic reserved type in e820 and EFI to
cover PMEM ranges.  The kernel can initialize PMEM ranges from
ACPI NFIT table alone.

This scheme causes a problem in the iomem table, though.  On x86,
for instance, e820_reserve_resources() initializes top-level entries
(iomem_resource.child) from the e820 table at early boot-time.
This creates "reserved" entry for a PMEM range, which does not allow
region_intersects() to check with PMEM type.

Change acpi_nfit_register_region() to call acpi_nfit_insert_resource(),
which calls insert_resource() to insert a PMEM entry from NFIT when
the iomem table does not have a PMEM entry already.  That is, when
a PMEM range is marked as reserved type in e820, it inserts
"Persistent Memory" entry, which results as follows.

 + "Persistent Memory"
    + "reserved"

This allows the EINJ driver, which calls region_intersects() to check
PMEM ranges, to work continuously even if BIOS sets reserved type
(or sets nothing) to PMEM ranges in e820 and EFI.

[1]: https://lists.gnu.org/archive/html/grub-devel/2015-11/msg00209.html
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Toshi Kani 2016-03-09 12:47:06 -07:00 committed by Dan Williams
parent 8095d0f225
commit af1996ef59
1 changed files with 48 additions and 0 deletions
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48
drivers/acpi/nfit.c
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@ -1571,6 +1571,48 @@ static int ars_status_process_records(struct nvdimm_bus *nvdimm_bus,
return 0;
}
static void acpi_nfit_remove_resource(void *data)
{
struct resource *res = data;
remove_resource(res);
}
static int acpi_nfit_insert_resource(struct acpi_nfit_desc *acpi_desc,
struct nd_region_desc *ndr_desc)
{
struct resource *res, *nd_res = ndr_desc->res;
int is_pmem, ret;
/* No operation if the region is already registered as PMEM */
is_pmem = region_intersects(nd_res->start, resource_size(nd_res),
IORESOURCE_MEM, IORES_DESC_PERSISTENT_MEMORY);
if (is_pmem == REGION_INTERSECTS)
return 0;
res = devm_kzalloc(acpi_desc->dev, sizeof(*res), GFP_KERNEL);
if (!res)
return -ENOMEM;
res->name = "Persistent Memory";
res->start = nd_res->start;
res->end = nd_res->end;
res->flags = IORESOURCE_MEM;
res->desc = IORES_DESC_PERSISTENT_MEMORY;
ret = insert_resource(&iomem_resource, res);
if (ret)
return ret;
ret = devm_add_action(acpi_desc->dev, acpi_nfit_remove_resource, res);
if (ret) {
remove_resource(res);
return ret;
}
return 0;
}
static int acpi_nfit_find_poison(struct acpi_nfit_desc *acpi_desc,
struct nd_region_desc *ndr_desc)
{
@ -1781,6 +1823,12 @@ static int acpi_nfit_register_region(struct acpi_nfit_desc *acpi_desc,
nvdimm_bus = acpi_desc->nvdimm_bus;
if (nfit_spa_type(spa) == NFIT_SPA_PM) {
rc = acpi_nfit_insert_resource(acpi_desc, ndr_desc);
if (rc)
dev_warn(acpi_desc->dev,
"failed to insert pmem resource to iomem: %d\n",
rc);
rc = acpi_nfit_find_poison(acpi_desc, ndr_desc);
if (rc) {
dev_err(acpi_desc->dev,