Commit cfe30b87 authored by Dan Williams's avatar Dan Williams

libnvdimm, pmem: adjust for section collisions with 'System RAM'

On a platform where 'Persistent Memory' and 'System RAM' are mixed
within a given sparsemem section, trim the namespace and notify about the
sub-optimal alignment.

Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent d9cbe09d
......@@ -133,6 +133,7 @@ bool nd_is_uuid_unique(struct device *dev, u8 *uuid)
bool pmem_should_map_pages(struct device *dev)
{
struct nd_region *nd_region = to_nd_region(dev->parent);
struct nd_namespace_io *nsio;
if (!IS_ENABLED(CONFIG_ZONE_DEVICE))
return false;
......@@ -143,6 +144,12 @@ bool pmem_should_map_pages(struct device *dev)
if (is_nd_pfn(dev) || is_nd_btt(dev))
return false;
nsio = to_nd_namespace_io(dev);
if (region_intersects(nsio->res.start, resource_size(&nsio->res),
IORESOURCE_SYSTEM_RAM,
IORES_DESC_NONE) == REGION_MIXED)
return false;
#ifdef ARCH_MEMREMAP_PMEM
return ARCH_MEMREMAP_PMEM == MEMREMAP_WB;
#else
......
......@@ -27,10 +27,13 @@ struct nd_pfn_sb {
__le32 flags;
__le16 version_major;
__le16 version_minor;
__le64 dataoff;
__le64 dataoff; /* relative to namespace_base + start_pad */
__le64 npfns;
__le32 mode;
u8 padding[4012];
/* minor-version-1 additions for section alignment */
__le32 start_pad;
__le32 end_trunc;
u8 padding[4004];
__le64 checksum;
};
......@@ -45,4 +48,7 @@ struct nd_pfn_sb {
#define PFN_SECTION_ALIGN_DOWN(x) (x)
#define PFN_SECTION_ALIGN_UP(x) (x)
#endif
#define PHYS_SECTION_ALIGN_DOWN(x) PFN_PHYS(PFN_SECTION_ALIGN_DOWN(PHYS_PFN(x)))
#define PHYS_SECTION_ALIGN_UP(x) PFN_PHYS(PFN_SECTION_ALIGN_UP(PHYS_PFN(x)))
#endif /* __NVDIMM_PFN_H */
......@@ -299,6 +299,11 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn)
if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0)
return -ENODEV;
if (__le16_to_cpu(pfn_sb->version_minor) < 1) {
pfn_sb->start_pad = 0;
pfn_sb->end_trunc = 0;
}
switch (le32_to_cpu(pfn_sb->mode)) {
case PFN_MODE_RAM:
case PFN_MODE_PMEM:
......
......@@ -43,7 +43,10 @@ struct pmem_device {
phys_addr_t data_offset;
u64 pfn_flags;
void __pmem *virt_addr;
/* immutable base size of the namespace */
size_t size;
/* trim size when namespace capacity has been section aligned */
u32 pfn_pad;
struct badblocks bb;
};
......@@ -145,7 +148,7 @@ static long pmem_direct_access(struct block_device *bdev, sector_t sector,
*kaddr = pmem->virt_addr + offset;
*pfn = phys_to_pfn_t(pmem->phys_addr + offset, pmem->pfn_flags);
return pmem->size - offset;
return pmem->size - pmem->pfn_pad - offset;
}
static const struct block_device_operations pmem_fops = {
......@@ -236,7 +239,8 @@ static int pmem_attach_disk(struct device *dev,
disk->flags = GENHD_FL_EXT_DEVT;
nvdimm_namespace_disk_name(ndns, disk->disk_name);
disk->driverfs_dev = dev;
set_capacity(disk, (pmem->size - pmem->data_offset) / 512);
set_capacity(disk, (pmem->size - pmem->pfn_pad - pmem->data_offset)
/ 512);
pmem->pmem_disk = disk;
devm_exit_badblocks(dev, &pmem->bb);
if (devm_init_badblocks(dev, &pmem->bb))
......@@ -279,6 +283,9 @@ 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;
u32 start_pad = 0, end_trunc = 0;
resource_size_t start, size;
struct nd_namespace_io *nsio;
struct nd_region *nd_region;
unsigned long npfns;
phys_addr_t offset;
......@@ -304,21 +311,56 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
}
memset(pfn_sb, 0, sizeof(*pfn_sb));
npfns = (pmem->size - SZ_8K) / SZ_4K;
/*
* Check if pmem collides with 'System RAM' when section aligned and
* trim it accordingly
*/
nsio = to_nd_namespace_io(&ndns->dev);
start = PHYS_SECTION_ALIGN_DOWN(nsio->res.start);
size = resource_size(&nsio->res);
if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
IORES_DESC_NONE) == REGION_MIXED) {
start = nsio->res.start;
start_pad = PHYS_SECTION_ALIGN_UP(start) - start;
}
start = nsio->res.start;
size = PHYS_SECTION_ALIGN_UP(start + size) - start;
if (region_intersects(start, size, IORESOURCE_SYSTEM_RAM,
IORES_DESC_NONE) == REGION_MIXED) {
size = resource_size(&nsio->res);
end_trunc = start + size - PHYS_SECTION_ALIGN_DOWN(start + size);
}
if (start_pad + end_trunc)
dev_info(&nd_pfn->dev, "%s section collision, truncate %d bytes\n",
dev_name(&ndns->dev), start_pad + end_trunc);
/*
* 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.
*/
start += start_pad;
npfns = (pmem->size - start_pad - end_trunc - SZ_8K) / SZ_4K;
if (nd_pfn->mode == PFN_MODE_PMEM)
offset = ALIGN(SZ_8K + 64 * npfns, nd_pfn->align);
offset = ALIGN(start + SZ_8K + 64 * npfns, nd_pfn->align)
- start;
else if (nd_pfn->mode == PFN_MODE_RAM)
offset = ALIGN(SZ_8K, nd_pfn->align);
offset = ALIGN(start + SZ_8K, nd_pfn->align) - start;
else
goto err;
npfns = (pmem->size - offset) / SZ_4K;
if (offset + start_pad + end_trunc >= pmem->size) {
dev_err(&nd_pfn->dev, "%s unable to satisfy requested alignment\n",
dev_name(&ndns->dev));
goto err;
}
npfns = (pmem->size - offset - start_pad - end_trunc) / 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);
......@@ -326,6 +368,9 @@ static int nd_pfn_init(struct nd_pfn *nd_pfn)
memcpy(pfn_sb->uuid, nd_pfn->uuid, 16);
memcpy(pfn_sb->parent_uuid, nd_dev_to_uuid(&ndns->dev), 16);
pfn_sb->version_major = cpu_to_le16(1);
pfn_sb->version_minor = cpu_to_le16(1);
pfn_sb->start_pad = cpu_to_le32(start_pad);
pfn_sb->end_trunc = cpu_to_le32(end_trunc);
checksum = nd_sb_checksum((struct nd_gen_sb *) pfn_sb);
pfn_sb->checksum = cpu_to_le64(checksum);
......@@ -376,41 +421,36 @@ static unsigned long init_altmap_reserve(resource_size_t base)
return reserve;
}
static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
static int __nvdimm_namespace_attach_pfn(struct nd_pfn *nd_pfn)
{
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 nd_region *nd_region;
struct vmem_altmap *altmap;
struct nd_pfn_sb *pfn_sb;
struct pmem_device *pmem;
struct request_queue *q;
phys_addr_t offset;
int rc;
struct resource res;
struct request_queue *q;
struct pmem_device *pmem;
struct vmem_altmap *altmap;
struct device *dev = &nd_pfn->dev;
struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb;
struct nd_namespace_common *ndns = nd_pfn->ndns;
u32 start_pad = __le32_to_cpu(pfn_sb->start_pad);
u32 end_trunc = __le32_to_cpu(pfn_sb->end_trunc);
struct nd_namespace_io *nsio = to_nd_namespace_io(&ndns->dev);
resource_size_t base = nsio->res.start + start_pad;
struct vmem_altmap __altmap = {
.base_pfn = init_altmap_base(nsio->res.start),
.reserve = init_altmap_reserve(nsio->res.start),
.base_pfn = init_altmap_base(base),
.reserve = init_altmap_reserve(base),
};
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;
pfn_sb = nd_pfn->pfn_sb;
offset = le64_to_cpu(pfn_sb->dataoff);
pmem = dev_get_drvdata(dev);
pmem->data_offset = le64_to_cpu(pfn_sb->dataoff);
pmem->pfn_pad = start_pad + end_trunc;
nd_pfn->mode = le32_to_cpu(nd_pfn->pfn_sb->mode);
if (nd_pfn->mode == PFN_MODE_RAM) {
if (offset < SZ_8K)
if (pmem->data_offset < SZ_8K)
return -EINVAL;
nd_pfn->npfns = le64_to_cpu(pfn_sb->npfns);
altmap = NULL;
} else if (nd_pfn->mode == PFN_MODE_PMEM) {
nd_pfn->npfns = (resource_size(&nsio->res) - offset)
nd_pfn->npfns = (pmem->size - pmem->pfn_pad - pmem->data_offset)
/ PAGE_SIZE;
if (le64_to_cpu(nd_pfn->pfn_sb->npfns) > nd_pfn->npfns)
dev_info(&nd_pfn->dev,
......@@ -418,7 +458,7 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
le64_to_cpu(nd_pfn->pfn_sb->npfns),
nd_pfn->npfns);
altmap = & __altmap;
altmap->free = __phys_to_pfn(offset - SZ_8K);
altmap->free = __phys_to_pfn(pmem->data_offset - SZ_8K);
altmap->alloc = 0;
} else {
rc = -ENXIO;
......@@ -426,10 +466,12 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
}
/* establish pfn range for lookup, and switch to direct map */
pmem = dev_get_drvdata(dev);
q = pmem->pmem_queue;
memcpy(&res, &nsio->res, sizeof(res));
res.start += start_pad;
res.end -= end_trunc;
devm_memunmap(dev, (void __force *) pmem->virt_addr);
pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &nsio->res,
pmem->virt_addr = (void __pmem *) devm_memremap_pages(dev, &res,
&q->q_usage_counter, altmap);
pmem->pfn_flags |= PFN_MAP;
if (IS_ERR(pmem->virt_addr)) {
......@@ -438,7 +480,6 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
}
/* attach pmem disk in "pfn-mode" */
pmem->data_offset = offset;
rc = pmem_attach_disk(dev, ndns, pmem);
if (rc)
goto err;
......@@ -447,6 +488,22 @@ static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
err:
nvdimm_namespace_detach_pfn(ndns);
return rc;
}
static int nvdimm_namespace_attach_pfn(struct nd_namespace_common *ndns)
{
struct nd_pfn *nd_pfn = to_nd_pfn(ndns->claim);
int rc;
if (!nd_pfn->uuid || !nd_pfn->ndns)
return -ENODEV;
rc = nd_pfn_init(nd_pfn);
if (rc)
return rc;
/* we need a valid pfn_sb before we can init a vmem_altmap */
return __nvdimm_namespace_attach_pfn(nd_pfn);
}
static int nd_pmem_probe(struct device *dev)
......
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