libnvdimm, nfit, nd_blk: driver for BLK-mode access persistent memory
The libnvdimm implementation handles allocating dimm address space (DPA)
between PMEM and BLK mode interfaces. After DPA has been allocated from
a BLK-region to a BLK-namespace the nd_blk driver attaches to handle I/O
as a struct bio based block device. Unlike PMEM, BLK is required to
handle platform specific details like mmio register formats and memory
controller interleave. For this reason the libnvdimm generic nd_blk
driver calls back into the bus provider to carry out the I/O.
This initial implementation handles the BLK interface defined by the
ACPI 6 NFIT [1] and the NVDIMM DSM Interface Example [2] composed from
DCR (dimm control region), BDW (block data window), IDT (interleave
descriptor) NFIT structures and the hardware register format.
[1]: http://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf
[2]: http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c
index fe8ec21..2cfb3f7 100644
--- a/drivers/nvdimm/region_devs.c
+++ b/drivers/nvdimm/region_devs.c
@@ -11,6 +11,7 @@
* General Public License for more details.
*/
#include <linux/scatterlist.h>
+#include <linux/highmem.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/sort.h>
@@ -34,7 +35,10 @@
}
free_percpu(nd_region->lane);
ida_simple_remove(®ion_ida, nd_region->id);
- kfree(nd_region);
+ if (is_nd_blk(dev))
+ kfree(to_nd_blk_region(dev));
+ else
+ kfree(nd_region);
}
static struct device_type nd_blk_device_type = {
@@ -71,6 +75,33 @@
}
EXPORT_SYMBOL_GPL(to_nd_region);
+struct nd_blk_region *to_nd_blk_region(struct device *dev)
+{
+ struct nd_region *nd_region = to_nd_region(dev);
+
+ WARN_ON(!is_nd_blk(dev));
+ return container_of(nd_region, struct nd_blk_region, nd_region);
+}
+EXPORT_SYMBOL_GPL(to_nd_blk_region);
+
+void *nd_region_provider_data(struct nd_region *nd_region)
+{
+ return nd_region->provider_data;
+}
+EXPORT_SYMBOL_GPL(nd_region_provider_data);
+
+void *nd_blk_region_provider_data(struct nd_blk_region *ndbr)
+{
+ return ndbr->blk_provider_data;
+}
+EXPORT_SYMBOL_GPL(nd_blk_region_provider_data);
+
+void nd_blk_region_set_provider_data(struct nd_blk_region *ndbr, void *data)
+{
+ ndbr->blk_provider_data = data;
+}
+EXPORT_SYMBOL_GPL(nd_blk_region_set_provider_data);
+
/**
* nd_region_to_nstype() - region to an integer namespace type
* @nd_region: region-device to interrogate
@@ -365,7 +396,8 @@
/*
* Upon successful probe/remove, take/release a reference on the
* associated interleave set (if present), and plant new btt + namespace
- * seeds.
+ * seeds. Also, on the removal of a BLK region, notify the provider to
+ * disable the region.
*/
static void nd_region_notify_driver_action(struct nvdimm_bus *nvdimm_bus,
struct device *dev, bool probe)
@@ -385,8 +417,14 @@
nd_mapping->labels = NULL;
put_ndd(ndd);
nd_mapping->ndd = NULL;
- atomic_dec(&nvdimm->busy);
+ if (ndd)
+ atomic_dec(&nvdimm->busy);
}
+
+ if (is_nd_pmem(dev))
+ return;
+
+ to_nd_blk_region(dev)->disable(nvdimm_bus, dev);
}
if (dev->parent && is_nd_blk(dev->parent) && probe) {
nd_region = to_nd_region(dev->parent);
@@ -526,11 +564,21 @@
};
EXPORT_SYMBOL_GPL(nd_mapping_attribute_group);
-void *nd_region_provider_data(struct nd_region *nd_region)
+int nd_blk_region_init(struct nd_region *nd_region)
{
- return nd_region->provider_data;
+ struct device *dev = &nd_region->dev;
+ struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(dev);
+
+ if (!is_nd_blk(dev))
+ return 0;
+
+ if (nd_region->ndr_mappings < 1) {
+ dev_err(dev, "invalid BLK region\n");
+ return -ENXIO;
+ }
+
+ return to_nd_blk_region(dev)->enable(nvdimm_bus, dev);
}
-EXPORT_SYMBOL_GPL(nd_region_provider_data);
/**
* nd_region_acquire_lane - allocate and lock a lane
@@ -591,6 +639,7 @@
{
struct nd_region *nd_region;
struct device *dev;
+ void *region_buf;
unsigned int i;
for (i = 0; i < ndr_desc->num_mappings; i++) {
@@ -605,10 +654,30 @@
}
}
- nd_region = kzalloc(sizeof(struct nd_region)
- + sizeof(struct nd_mapping) * ndr_desc->num_mappings,
- GFP_KERNEL);
- if (!nd_region)
+ if (dev_type == &nd_blk_device_type) {
+ struct nd_blk_region_desc *ndbr_desc;
+ struct nd_blk_region *ndbr;
+
+ ndbr_desc = to_blk_region_desc(ndr_desc);
+ ndbr = kzalloc(sizeof(*ndbr) + sizeof(struct nd_mapping)
+ * ndr_desc->num_mappings,
+ GFP_KERNEL);
+ if (ndbr) {
+ nd_region = &ndbr->nd_region;
+ ndbr->enable = ndbr_desc->enable;
+ ndbr->disable = ndbr_desc->disable;
+ ndbr->do_io = ndbr_desc->do_io;
+ }
+ region_buf = ndbr;
+ } else {
+ nd_region = kzalloc(sizeof(struct nd_region)
+ + sizeof(struct nd_mapping)
+ * ndr_desc->num_mappings,
+ GFP_KERNEL);
+ region_buf = nd_region;
+ }
+
+ if (!region_buf)
return NULL;
nd_region->id = ida_simple_get(®ion_ida, 0, 0, GFP_KERNEL);
if (nd_region->id < 0)
@@ -654,7 +723,7 @@
err_percpu:
ida_simple_remove(®ion_ida, nd_region->id);
err_id:
- kfree(nd_region);
+ kfree(region_buf);
return NULL;
}