libnvdimm, pmem: 'struct page' for pmem
Enable the pmem driver to handle PFN device instances. Attaching a pmem
namespace to a pfn device triggers the driver to allocate and initialize
struct page entries for pmem. Memory capacity for this allocation comes
exclusively from RAM for now which is suitable for low PMEM to RAM
ratios. This mechanism will be expanded later for setting an "allocate
from PMEM" policy.
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/nvdimm/Kconfig b/drivers/nvdimm/Kconfig
index ace25b5..53c1162 100644
--- a/drivers/nvdimm/Kconfig
+++ b/drivers/nvdimm/Kconfig
@@ -76,6 +76,7 @@
config NVDIMM_PFN
bool "PFN: Map persistent (device) memory"
default LIBNVDIMM
+ depends on ZONE_DEVICE
select ND_CLAIM
help
Map persistent memory, i.e. advertise it to the memory
diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h
index 8da2be1..83e5d09 100644
--- a/drivers/nvdimm/nd.h
+++ b/drivers/nvdimm/nd.h
@@ -217,6 +217,7 @@
int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata);
bool is_nd_pfn(struct device *dev);
struct device *nd_pfn_create(struct nd_region *nd_region);
+int nd_pfn_validate(struct nd_pfn *nd_pfn);
#else
static inline int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
{
@@ -232,6 +233,11 @@
{
return NULL;
}
+
+static inline int nd_pfn_validate(struct nd_pfn *nd_pfn)
+{
+ return -ENODEV;
+}
#endif
struct nd_region *to_nd_region(struct device *dev);
diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c
index f708d63..3fd7d0d 100644
--- a/drivers/nvdimm/pfn_devs.c
+++ b/drivers/nvdimm/pfn_devs.c
@@ -228,7 +228,7 @@
return dev;
}
-static int nd_pfn_validate(struct nd_pfn *nd_pfn)
+int nd_pfn_validate(struct nd_pfn *nd_pfn)
{
struct nd_namespace_common *ndns = nd_pfn->ndns;
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
@@ -286,10 +286,10 @@
*/
offset = le64_to_cpu(pfn_sb->dataoff);
nsio = to_nd_namespace_io(&ndns->dev);
- if ((nsio->res.start + offset) & (ND_PFN_ALIGN - 1)) {
+ if (nsio->res.start & ND_PFN_MASK) {
dev_err(&nd_pfn->dev,
- "init failed: %s with offset %#llx not section aligned\n",
- dev_name(&ndns->dev), offset);
+ "init failed: %s not section aligned\n",
+ dev_name(&ndns->dev));
return -EBUSY;
} else if (offset >= resource_size(&nsio->res)) {
dev_err(&nd_pfn->dev, "pfn array size exceeds capacity of %s\n",
@@ -299,6 +299,7 @@
return 0;
}
+EXPORT_SYMBOL(nd_pfn_validate);
int nd_pfn_probe(struct nd_namespace_common *ndns, void *drvdata)
{
diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 20bf122..2f885e5 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -21,18 +21,24 @@
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/module.h>
+#include <linux/memory_hotplug.h>
#include <linux/moduleparam.h>
+#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/pmem.h>
#include <linux/nd.h>
+#include "pfn.h"
#include "nd.h"
struct pmem_device {
struct request_queue *pmem_queue;
struct gendisk *pmem_disk;
+ struct nd_namespace_common *ndns;
/* One contiguous memory region per device */
phys_addr_t phys_addr;
+ /* when non-zero this device is hosting a 'pfn' instance */
+ phys_addr_t data_offset;
void __pmem *virt_addr;
size_t size;
};
@@ -44,7 +50,7 @@
sector_t sector)
{
void *mem = kmap_atomic(page);
- size_t pmem_off = sector << 9;
+ phys_addr_t pmem_off = sector * 512 + pmem->data_offset;
void __pmem *pmem_addr = pmem->virt_addr + pmem_off;
if (rw == READ) {
@@ -95,16 +101,23 @@
void __pmem **kaddr, unsigned long *pfn)
{
struct pmem_device *pmem = bdev->bd_disk->private_data;
- size_t offset = sector << 9;
+ resource_size_t offset = sector * 512 + pmem->data_offset;
+ resource_size_t size;
- if (!pmem)
- return -ENODEV;
+ if (pmem->data_offset) {
+ /*
+ * Limit the direct_access() size to what is covered by
+ * the memmap
+ */
+ size = (pmem->size - offset) & ~ND_PFN_MASK;
+ } else
+ size = pmem->size - offset;
/* FIXME convert DAX to comprehend that this mapping has a lifetime */
*kaddr = pmem->virt_addr + offset;
*pfn = (pmem->phys_addr + offset) >> PAGE_SHIFT;
- return pmem->size - offset;
+ return size;
}
static const struct block_device_operations pmem_fops = {
@@ -144,13 +157,16 @@
static void pmem_detach_disk(struct pmem_device *pmem)
{
+ if (!pmem->pmem_disk)
+ return;
+
del_gendisk(pmem->pmem_disk);
put_disk(pmem->pmem_disk);
blk_cleanup_queue(pmem->pmem_queue);
}
-static int pmem_attach_disk(struct nd_namespace_common *ndns,
- struct pmem_device *pmem)
+static int pmem_attach_disk(struct device *dev,
+ struct nd_namespace_common *ndns, struct pmem_device *pmem)
{
struct gendisk *disk;
@@ -177,8 +193,8 @@
disk->queue = pmem->pmem_queue;
disk->flags = GENHD_FL_EXT_DEVT;
nvdimm_namespace_disk_name(ndns, disk->disk_name);
- disk->driverfs_dev = &ndns->dev;
- set_capacity(disk, pmem->size >> 9);
+ disk->driverfs_dev = dev;
+ set_capacity(disk, (pmem->size - pmem->data_offset) / 512);
pmem->pmem_disk = disk;
add_disk(disk);
@@ -207,6 +223,154 @@
return 0;
}
+static int nd_pfn_init(struct nd_pfn *nd_pfn)
+{
+ struct nd_pfn_sb *pfn_sb = kzalloc(sizeof(*pfn_sb), GFP_KERNEL);
+ struct pmem_device *pmem = dev_get_drvdata(&nd_pfn->dev);
+ struct nd_namespace_common *ndns = nd_pfn->ndns;
+ struct nd_region *nd_region;
+ unsigned long npfns;
+ phys_addr_t offset;
+ u64 checksum;
+ int rc;
+
+ if (!pfn_sb)
+ return -ENOMEM;
+
+ nd_pfn->pfn_sb = pfn_sb;
+ rc = nd_pfn_validate(nd_pfn);
+ if (rc == 0 || rc == -EBUSY)
+ return rc;
+
+ /* section alignment for simple hotplug */
+ if (nvdimm_namespace_capacity(ndns) < ND_PFN_ALIGN
+ || pmem->phys_addr & ND_PFN_MASK)
+ return -ENODEV;
+
+ nd_region = to_nd_region(nd_pfn->dev.parent);
+ if (nd_region->ro) {
+ dev_info(&nd_pfn->dev,
+ "%s is read-only, unable to init metadata\n",
+ dev_name(&nd_region->dev));
+ goto err;
+ }
+
+ memset(pfn_sb, 0, sizeof(*pfn_sb));
+ npfns = (pmem->size - SZ_8K) / SZ_4K;
+ /*
+ * Note, we use 64 here for the standard size of struct page,
+ * debugging options may cause it to be larger in which case the
+ * implementation will limit the pfns advertised through
+ * ->direct_access() to those that are included in the memmap.
+ */
+ if (nd_pfn->mode == PFN_MODE_PMEM)
+ offset = ALIGN(SZ_8K + 64 * npfns, PMD_SIZE);
+ else if (nd_pfn->mode == PFN_MODE_RAM)
+ offset = SZ_8K;
+ else
+ goto err;
+
+ npfns = (pmem->size - offset) / SZ_4K;
+ pfn_sb->mode = cpu_to_le32(nd_pfn->mode);
+ pfn_sb->dataoff = cpu_to_le64(offset);
+ pfn_sb->npfns = cpu_to_le64(npfns);
+ memcpy(pfn_sb->signature, PFN_SIG, PFN_SIG_LEN);
+ memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
+ pfn_sb->version_major = cpu_to_le16(1);
+ checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
+ pfn_sb->checksum = cpu_to_le64(checksum);
+
+ rc = nvdimm_write_bytes(ndns, SZ_4K, pfn_sb, sizeof(*pfn_sb));
+ if (rc)
+ goto err;
+
+ return 0;
+ err:
+ nd_pfn->pfn_sb = NULL;
+ kfree(pfn_sb);
+ return -ENXIO;
+}
+
+static int nvdimm_namespace_detach_pfn(struct nd_namespace_common *ndns)
+{
+ struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
+ struct pmem_device *pmem;
+
+ /* free pmem disk */
+ pmem = dev_get_drvdata(&nd_pfn->dev);
+ pmem_detach_disk(pmem);
+
+ /* release nd_pfn resources */
+ kfree(nd_pfn->pfn_sb);
+ nd_pfn->pfn_sb = NULL;
+
+ return 0;
+}
+
+static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
+{
+ struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
+ struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
+ struct device *dev = &nd_pfn->dev;
+ struct vmem_altmap *altmap;
+ struct nd_region *nd_region;
+ struct nd_pfn_sb *pfn_sb;
+ struct pmem_device *pmem;
+ phys_addr_t offset;
+ int rc;
+
+ if (!nd_pfn->uuid || !nd_pfn->ndns)
+ return -ENODEV;
+
+ nd_region = to_nd_region(dev->parent);
+ rc = nd_pfn_init(nd_pfn);
+ if (rc)
+ return rc;
+
+ if (PAGE_SIZE != SZ_4K) {
+ dev_err(dev, "only supported on systems with 4K PAGE_SIZE\n");
+ return -ENXIO;
+ }
+ if (nsio->res.start & ND_PFN_MASK) {
+ dev_err(dev, "%s not memory hotplug section aligned\n",
+ dev_name(&ndns->dev));
+ return -ENXIO;
+ }
+
+ pfn_sb = nd_pfn->pfn_sb;
+ offset = le64_to_cpu(pfn_sb->dataoff);
+ nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
+ if (nd_pfn->mode == PFN_MODE_RAM) {
+ if (offset != SZ_8K)
+ return -EINVAL;
+ nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
+ altmap = NULL;
+ } else {
+ rc = -ENXIO;
+ goto err;
+ }
+
+ /* establish pfn range for lookup, and switch to direct map */
+ pmem = dev_get_drvdata(dev);
+ memunmap_pmem(dev, pmem->virt_addr);
+ pmem->virt_addr = (void __pmem *)devm_memremap_pages(dev, &nsio->res);
+ if (IS_ERR(pmem->virt_addr)) {
+ rc = PTR_ERR(pmem->virt_addr);
+ goto err;
+ }
+
+ /* attach pmem disk in "pfn-mode" */
+ pmem->data_offset = offset;
+ rc = pmem_attach_disk(dev, ndns, pmem);
+ if (rc)
+ goto err;
+
+ return rc;
+ err:
+ nvdimm_namespace_detach_pfn(ndns);
+ return rc;
+}
+
static int nd_pmem_probe(struct device *dev)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
@@ -223,16 +387,27 @@
if (IS_ERR(pmem))
return PTR_ERR(pmem);
+ pmem->ndns = ndns;
dev_set_drvdata(dev, pmem);
ndns->rw_bytes = pmem_rw_bytes;
if (is_nd_btt(dev))
return nvdimm_namespace_attach_btt(ndns);
- if (nd_btt_probe(ndns, pmem) == 0)
+ if (is_nd_pfn(dev))
+ return nvdimm_namespace_attach_pfn(ndns);
+
+ if (nd_btt_probe(ndns, pmem) == 0) {
/* we'll come back as btt-pmem */
return -ENXIO;
- return pmem_attach_disk(ndns, pmem);
+ }
+
+ if (nd_pfn_probe(ndns, pmem) == 0) {
+ /* we'll come back as pfn-pmem */
+ return -ENXIO;
+ }
+
+ return pmem_attach_disk(dev, ndns, pmem);
}
static int nd_pmem_remove(struct device *dev)
@@ -240,7 +415,9 @@
struct pmem_device *pmem = dev_get_drvdata(dev);
if (is_nd_btt(dev))
- nvdimm_namespace_detach_btt(to_nd_btt(dev)->ndns);
+ nvdimm_namespace_detach_btt(pmem->ndns);
+ else if (is_nd_pfn(dev))
+ nvdimm_namespace_detach_pfn(pmem->ndns);
else
pmem_detach_disk(pmem);
diff --git a/tools/testing/nvdimm/Kbuild b/tools/testing/nvdimm/Kbuild
index 99e70f0..38b00ec 100644
--- a/tools/testing/nvdimm/Kbuild
+++ b/tools/testing/nvdimm/Kbuild
@@ -2,6 +2,7 @@
ldflags-y += --wrap=memremap
ldflags-y += --wrap=devm_ioremap_nocache
ldflags-y += --wrap=devm_memremap
+ldflags-y += --wrap=devm_memunmap
ldflags-y += --wrap=ioremap_nocache
ldflags-y += --wrap=iounmap
ldflags-y += --wrap=memunmap
diff --git a/tools/testing/nvdimm/test/iomap.c b/tools/testing/nvdimm/test/iomap.c
index 179d228..b725131 100644
--- a/tools/testing/nvdimm/test/iomap.c
+++ b/tools/testing/nvdimm/test/iomap.c
@@ -108,6 +108,19 @@
}
EXPORT_SYMBOL(__wrap_memremap);
+void __wrap_devm_memunmap(struct device *dev, void *addr)
+{
+ struct nfit_test_resource *nfit_res;
+
+ rcu_read_lock();
+ nfit_res = get_nfit_res((unsigned long) addr);
+ rcu_read_unlock();
+ if (nfit_res)
+ return;
+ return devm_memunmap(dev, addr);
+}
+EXPORT_SYMBOL(__wrap_devm_memunmap);
+
void __iomem *__wrap_ioremap_nocache(resource_size_t offset, unsigned long size)
{
return __nfit_test_ioremap(offset, size, ioremap_nocache);
