[PATCH] libnvdimm/dimm: Add a no-BLK quirk based on NVDIMM family

From: Dan Williams
Date: Sat Feb 02 2019 - 20:26:16 EST


As Dexuan reports the NVDIMM_FAMILY_HYPERV platform is incompatible with
the existing Linux namespace implementation because it uses
NSLABEL_FLAG_LOCAL for x1-width PMEM interleave sets. Quirk it as an
platform / DIMM that does not provide BLK-aperture access. Allow the
libnvdimm core to assume no potential for aliasing. In case other
implementations make the same mistake, provide a "noblk" module
parameter to force-enable the quirk.

Link: https://lkml.kernel.org/r/PU1P153MB0169977604493B82B662A01CBF920@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/acpi/nfit/core.c | 4 ++++
drivers/nvdimm/dimm_devs.c | 7 ++++++-
drivers/nvdimm/label.c | 3 +++
drivers/nvdimm/namespace_devs.c | 6 ++++++
drivers/nvdimm/region_devs.c | 7 +++++++
include/linux/libnvdimm.h | 2 ++
6 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 4a7e8b1fa43b..811c399a3a76 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -2016,6 +2016,10 @@ static int acpi_nfit_register_dimms(struct acpi_nfit_desc *acpi_desc)
cmd_mask |= nfit_mem->dsm_mask & NVDIMM_STANDARD_CMDMASK;
}

+ /* Quirk to ignore LOCAL for labels on HYPERV DIMMs */
+ if (nfit_mem->family == NVDIMM_FAMILY_HYPERV)
+ set_bit(NDD_NOBLK, &flags);
+
if (test_bit(NFIT_MEM_LSR, &nfit_mem->flags)) {
set_bit(ND_CMD_GET_CONFIG_SIZE, &cmd_mask);
set_bit(ND_CMD_GET_CONFIG_DATA, &cmd_mask);
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c
index 4890310df874..186d63f16434 100644
--- a/drivers/nvdimm/dimm_devs.c
+++ b/drivers/nvdimm/dimm_devs.c
@@ -11,6 +11,7 @@
* General Public License for more details.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/moduleparam.h>
#include <linux/vmalloc.h>
#include <linux/device.h>
#include <linux/ndctl.h>
@@ -25,6 +26,10 @@

static DEFINE_IDA(dimm_ida);

+static bool noblk;
+module_param(noblk, bool, 0444);
+MODULE_PARM_DESC(noblk, "force disable BLK / local alias support");
+
/*
* Retrieve bus and dimm handle and return if this bus supports
* get_config_data commands
@@ -551,7 +556,7 @@ struct nvdimm *__nvdimm_create(struct nvdimm_bus *nvdimm_bus,

nvdimm->dimm_id = dimm_id;
nvdimm->provider_data = provider_data;
- nvdimm->flags = flags;
+ nvdimm->flags = flags | noblk ? (1 << NDD_NOBLK) : 0;
nvdimm->cmd_mask = cmd_mask;
nvdimm->num_flush = num_flush;
nvdimm->flush_wpq = flush_wpq;
diff --git a/drivers/nvdimm/label.c b/drivers/nvdimm/label.c
index 6d6e9a12150b..f3d753d3169c 100644
--- a/drivers/nvdimm/label.c
+++ b/drivers/nvdimm/label.c
@@ -392,6 +392,7 @@ int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd)
return 0; /* no label, nothing to reserve */

for_each_clear_bit_le(slot, free, nslot) {
+ struct nvdimm *nvdimm = to_nvdimm(ndd->dev);
struct nd_namespace_label *nd_label;
struct nd_region *nd_region = NULL;
u8 label_uuid[NSLABEL_UUID_LEN];
@@ -406,6 +407,8 @@ int nd_label_reserve_dpa(struct nvdimm_drvdata *ndd)

memcpy(label_uuid, nd_label->uuid, NSLABEL_UUID_LEN);
flags = __le32_to_cpu(nd_label->flags);
+ if (test_bit(NDD_NOBLK, &nvdimm->flags))
+ flags &= ~NSLABEL_FLAG_LOCAL;
nd_label_gen_id(&label_id, label_uuid, flags);
res = nvdimm_allocate_dpa(ndd, &label_id,
__le64_to_cpu(nd_label->dpa),
diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 4b077555ac70..3677b0c4a33d 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -2492,6 +2492,12 @@ static int init_active_labels(struct nd_region *nd_region)
if (!label_ent)
break;
label = nd_label_active(ndd, j);
+ if (test_bit(NDD_NOBLK, &nvdimm->flags)) {
+ u32 flags = __le32_to_cpu(label->flags);
+
+ flags &= ~NSLABEL_FLAG_LOCAL;
+ label->flags = __cpu_to_le32(flags);
+ }
label_ent->label = label;

mutex_lock(&nd_mapping->lock);
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index e2818f94f292..3b58baa44b5c 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -1003,6 +1003,13 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus,

if (test_bit(NDD_UNARMED, &nvdimm->flags))
ro = 1;
+
+ if (test_bit(NDD_NOBLK, &nvdimm->flags)
+ && dev_type == &nd_blk_device_type) {
+ dev_err(&nvdimm_bus->dev, "%s: %s mapping%d is not BLK capable\n",
+ caller, dev_name(&nvdimm->dev), i);
+ return NULL;
+ }
}

if (dev_type == &nd_blk_device_type) {
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 5440f11b0907..7da406ae3a2b 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -42,6 +42,8 @@ enum {
NDD_SECURITY_OVERWRITE = 3,
/* tracking whether or not there is a pending device reference */
NDD_WORK_PENDING = 4,
+ /* ignore / filter NSLABEL_FLAG_LOCAL for this DIMM, i.e. no aliasing */
+ NDD_NOBLK = 5,

/* need to set a limit somewhere, but yes, this is likely overkill */
ND_IOCTL_MAX_BUFLEN = SZ_4M,