This patch adds codes to treat a volatile virtual CD region as a
read-only pmem region, then read-only /dev/pmem* device can be mounted
with iso9660.
It's useful to work with the httpboot in EFI firmware to pull a remote
ISO file to the local memory region for booting and installation.
Wiki page of UEFI HTTPBoot with OVMF:
https://en.opensuse.org/UEFI_HTTPBoot_with_OVMF
Signed-off-by: Lee, Chun-Yi <j...@suse.com>
Cc: Gary Lin <g...@suse.com>
Cc: Dan Williams <dan.j.willi...@intel.com>
Cc: Ross Zwisler <ross.zwis...@linux.intel.com>
Cc: "Rafael J. Wysocki" <r...@rjwysocki.net>
---
drivers/acpi/nfit.c | 8 +++++++-
drivers/nvdimm/region_devs.c | 26 +++++++++++++++++++++++++-
include/linux/libnvdimm.h | 2 ++
3 files changed, 34 insertions(+), 2 deletions(-)
diff --git a/drivers/acpi/nfit.c b/drivers/acpi/nfit.c
index 2215fc8..b100a17 100644
--- a/drivers/acpi/nfit.c
+++ b/drivers/acpi/nfit.c
@@ -1949,6 +1949,7 @@ static int acpi_nfit_init_mapping(struct acpi_nfit_desc
*acpi_desc,
switch (nfit_spa_type(spa)) {
case NFIT_SPA_PM:
case NFIT_SPA_VOLATILE:
+ case NFIT_SPA_VCD:
nd_mapping->start = memdev->address;
nd_mapping->size = memdev->region_size;
break;
@@ -1995,7 +1996,7 @@ static int acpi_nfit_register_region(struct
acpi_nfit_desc *acpi_desc,
if (nfit_spa->nd_region)
return 0;
- if (spa->range_index == 0) {
+ if (spa->range_index == 0 && nfit_spa_type(spa) != NFIT_SPA_VCD) {
dev_dbg(acpi_desc->dev, "%s: detected invalid spa index\n",
__func__);
return 0;
@@ -2059,6 +2060,11 @@ static int acpi_nfit_register_region(struct
acpi_nfit_desc *acpi_desc,
ndr_desc);
if (!nfit_spa->nd_region)
rc = -ENOMEM;
+ } else if (nfit_spa_type(spa) == NFIT_SPA_VCD) {
+ nfit_spa->nd_region = nvdimm_vcd_region_create(nvdimm_bus,
+ ndr_desc);
+ if (!nfit_spa->nd_region)
+ rc = -ENOMEM;
}
out:
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index 40fcfea..f155941 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -56,9 +56,19 @@ static struct device_type nd_volatile_device_type = {
.release = nd_region_release,
};
+static struct device_type nd_vcd_device_type = {
+ .name = "nd_vcd",
+ .release = nd_region_release,
+};
+
+bool is_nd_vcd(struct device *dev)
+{
+ return dev ? dev->type == &nd_vcd_device_type : false;
+}
+
bool is_nd_pmem(struct device *dev)
{
- return dev ? dev->type == &nd_pmem_device_type : false;
+ return dev ? dev->type == &nd_pmem_device_type || is_nd_vcd(dev) :
false;
}
bool is_nd_blk(struct device *dev)
@@ -338,6 +348,9 @@ static ssize_t read_only_store(struct device *dev,
int rc = strtobool(buf, &ro);
struct nd_region *nd_region = to_nd_region(dev);
+ if (is_nd_vcd(dev))
+ return -ENXIO;
+
if (rc)
return rc;
@@ -687,6 +700,9 @@ static struct nd_region *nd_region_create(struct nvdimm_bus
*nvdimm_bus,
ro = 1;
}
+ if (dev_type == &nd_vcd_device_type)
+ ro = 1;
+
if (dev_type == &nd_blk_device_type) {
struct nd_blk_region_desc *ndbr_desc;
struct nd_blk_region *ndbr;
@@ -774,6 +790,14 @@ struct nd_region *nvdimm_pmem_region_create(struct
nvdimm_bus *nvdimm_bus,
}
EXPORT_SYMBOL_GPL(nvdimm_pmem_region_create);
+struct nd_region *nvdimm_vcd_region_create(struct nvdimm_bus *nvdimm_bus,
+ struct nd_region_desc *ndr_desc)
+{
+ return nd_region_create(nvdimm_bus, ndr_desc, &nd_vcd_device_type,
+ __func__);
+}
+EXPORT_SYMBOL_GPL(nvdimm_vcd_region_create);
+
struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
struct nd_region_desc *ndr_desc)
{
diff --git a/include/linux/libnvdimm.h b/include/linux/libnvdimm.h
index 0c3c30c..0a1f949 100644
--- a/include/linux/libnvdimm.h
+++ b/include/linux/libnvdimm.h
@@ -145,6 +145,8 @@ u32 nd_cmd_out_size(struct nvdimm *nvdimm, int cmd,
int nvdimm_bus_check_dimm_count(struct nvdimm_bus *nvdimm_bus, int dimm_count);
struct nd_region *nvdimm_pmem_region_create(struct nvdimm_bus *nvdimm_bus,
struct nd_region_desc *ndr_desc);
+struct nd_region *nvdimm_vcd_region_create(struct nvdimm_bus *nvdimm_bus,
+ struct nd_region_desc *ndr_desc);
struct nd_region *nvdimm_blk_region_create(struct nvdimm_bus *nvdimm_bus,
struct nd_region_desc *ndr_desc);
struct nd_region *nvdimm_volatile_region_create(struct nvdimm_bus *nvdimm_bus,
--
2.1.4
