Commit 2522afb86a8cceba0f67dbf05772d21b76d79f06 upstream. The align attribute applies an alignment constraint for namespace creation in a region. Whereas the 'align' attribute of a namespace applied alignment padding via an info block, the 'align' attribute applies alignment constraints to the free space allocation. The default for 'align' is the maximum known memremap_compat_align() across all archs (16MiB from PowerPC at time of writing) multiplied by the number of interleave ways if there is blk-aliasing. The minimum is PAGE_SIZE and allows for the creation of cross-arch incompatible namespaces, just as previous kernels allowed, but the expectation is cross-arch and mode-independent compatibility by default. The regression risk with this change is limited to cases that were dependent on the ability to create unaligned namespaces, *and* for some reason are unable to opt-out of aligned namespaces by writing to 'regionX/align'. If such a scenario arises the default can be flipped from opt-out to opt-in of compat-aligned namespace creation, but that is a last resort. The kernel will otherwise continue to support existing defined misaligned namespaces. Unfortunately this change needs to touch several parts of the implementation at once: - region/available_size: expand busy extents to current align - region/max_available_extent: expand busy extents to current align - namespace/size: trim free space to current align ...to keep the free space accounting conforming to the dynamic align setting. Reported-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Reported-by: Jeff Moyer <jmoyer@xxxxxxxxxx> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx> Reviewed-by: Jeff Moyer <jmoyer@xxxxxxxxxx> Link: https://lore.kernel.org/r/158041478371.3889308.14542630147672668068.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- drivers/nvdimm/dimm_devs.c | 86 +++++++++++++++++++++++----- drivers/nvdimm/namespace_devs.c | 9 ++- drivers/nvdimm/nd.h | 1 drivers/nvdimm/region_devs.c | 120 ++++++++++++++++++++++++++++++++++++--- 4 files changed, 190 insertions(+), 26 deletions(-) diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c index def5c2846bea..8c773fb60296 100644 --- a/drivers/nvdimm/dimm_devs.c +++ b/drivers/nvdimm/dimm_devs.c @@ -557,6 +557,21 @@ int nvdimm_security_freeze(struct nvdimm *nvdimm) return rc; } +static unsigned long dpa_align(struct nd_region *nd_region) +{ + struct device *dev = &nd_region->dev; + + if (dev_WARN_ONCE(dev, !is_nvdimm_bus_locked(dev), + "bus lock required for capacity provision\n")) + return 0; + if (dev_WARN_ONCE(dev, !nd_region->ndr_mappings || nd_region->align + % nd_region->ndr_mappings, + "invalid region align %#lx mappings: %d\n", + nd_region->align, nd_region->ndr_mappings)) + return 0; + return nd_region->align / nd_region->ndr_mappings; +} + int alias_dpa_busy(struct device *dev, void *data) { resource_size_t map_end, blk_start, new; @@ -565,6 +580,7 @@ int alias_dpa_busy(struct device *dev, void *data) struct nd_region *nd_region; struct nvdimm_drvdata *ndd; struct resource *res; + unsigned long align; int i; if (!is_memory(dev)) @@ -602,13 +618,21 @@ int alias_dpa_busy(struct device *dev, void *data) * Find the free dpa from the end of the last pmem allocation to * the end of the interleave-set mapping. */ + align = dpa_align(nd_region); + if (!align) + return 0; + for_each_dpa_resource(ndd, res) { + resource_size_t start, end; + if (strncmp(res->name, "pmem", 4) != 0) continue; - if ((res->start >= blk_start && res->start < map_end) - || (res->end >= blk_start - && res->end <= map_end)) { - new = max(blk_start, min(map_end + 1, res->end + 1)); + + start = ALIGN_DOWN(res->start, align); + end = ALIGN(res->end + 1, align) - 1; + if ((start >= blk_start && start < map_end) + || (end >= blk_start && end <= map_end)) { + new = max(blk_start, min(map_end, end) + 1); if (new != blk_start) { blk_start = new; goto retry; @@ -648,6 +672,7 @@ resource_size_t nd_blk_available_dpa(struct nd_region *nd_region) .res = NULL, }; struct resource *res; + unsigned long align; if (!ndd) return 0; @@ -655,10 +680,20 @@ resource_size_t nd_blk_available_dpa(struct nd_region *nd_region) device_for_each_child(&nvdimm_bus->dev, &info, alias_dpa_busy); /* now account for busy blk allocations in unaliased dpa */ + align = dpa_align(nd_region); + if (!align) + return 0; for_each_dpa_resource(ndd, res) { + resource_size_t start, end, size; + if (strncmp(res->name, "blk", 3) != 0) continue; - info.available -= resource_size(res); + start = ALIGN_DOWN(res->start, align); + end = ALIGN(res->end + 1, align) - 1; + size = end - start + 1; + if (size >= info.available) + return 0; + info.available -= size; } return info.available; @@ -677,19 +712,31 @@ resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region *nd_region, struct nvdimm_bus *nvdimm_bus; resource_size_t max = 0; struct resource *res; + unsigned long align; /* if a dimm is disabled the available capacity is zero */ if (!ndd) return 0; + align = dpa_align(nd_region); + if (!align) + return 0; + nvdimm_bus = walk_to_nvdimm_bus(ndd->dev); if (__reserve_free_pmem(&nd_region->dev, nd_mapping->nvdimm)) return 0; for_each_dpa_resource(ndd, res) { + resource_size_t start, end; + if (strcmp(res->name, "pmem-reserve") != 0) continue; - if (resource_size(res) > max) - max = resource_size(res); + /* trim free space relative to current alignment setting */ + start = ALIGN(res->start, align); + end = ALIGN_DOWN(res->end + 1, align) - 1; + if (end < start) + continue; + if (end - start + 1 > max) + max = end - start + 1; } release_free_pmem(nvdimm_bus, nd_mapping); return max; @@ -717,24 +764,33 @@ resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region, struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); struct resource *res; const char *reason; + unsigned long align; if (!ndd) return 0; + align = dpa_align(nd_region); + if (!align) + return 0; + map_start = nd_mapping->start; map_end = map_start + nd_mapping->size - 1; blk_start = max(map_start, map_end + 1 - *overlap); for_each_dpa_resource(ndd, res) { - if (res->start >= map_start && res->start < map_end) { + resource_size_t start, end; + + start = ALIGN_DOWN(res->start, align); + end = ALIGN(res->end + 1, align) - 1; + if (start >= map_start && start < map_end) { if (strncmp(res->name, "blk", 3) == 0) blk_start = min(blk_start, - max(map_start, res->start)); - else if (res->end > map_end) { + max(map_start, start)); + else if (end > map_end) { reason = "misaligned to iset"; goto err; } else - busy += resource_size(res); - } else if (res->end >= map_start && res->end <= map_end) { + busy += end - start + 1; + } else if (end >= map_start && end <= map_end) { if (strncmp(res->name, "blk", 3) == 0) { /* * If a BLK allocation overlaps the start of @@ -743,8 +799,8 @@ resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region, */ blk_start = map_start; } else - busy += resource_size(res); - } else if (map_start > res->start && map_start < res->end) { + busy += end - start + 1; + } else if (map_start > start && map_start < end) { /* total eclipse of the mapping */ busy += nd_mapping->size; blk_start = map_start; @@ -754,7 +810,7 @@ resource_size_t nd_pmem_available_dpa(struct nd_region *nd_region, *overlap = map_end + 1 - blk_start; available = blk_start - map_start; if (busy < available) - return available - busy; + return ALIGN_DOWN(available - busy, align); return 0; err: diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index 8cf1c8932a3b..e80de9b9ccce 100644 --- a/drivers/nvdimm/namespace_devs.c +++ b/drivers/nvdimm/namespace_devs.c @@ -568,6 +568,11 @@ static void space_valid(struct nd_region *nd_region, struct nvdimm_drvdata *ndd, { bool is_reserve = strcmp(label_id->id, "pmem-reserve") == 0; bool is_pmem = strncmp(label_id->id, "pmem", 4) == 0; + unsigned long align; + + align = nd_region->align / nd_region->ndr_mappings; + valid->start = ALIGN(valid->start, align); + valid->end = ALIGN_DOWN(valid->end + 1, align) - 1; if (valid->start >= valid->end) goto invalid; @@ -1007,10 +1012,10 @@ static ssize_t __size_store(struct device *dev, unsigned long long val) return -ENXIO; } - div_u64_rem(val, PAGE_SIZE * nd_region->ndr_mappings, &remainder); + div_u64_rem(val, nd_region->align, &remainder); if (remainder) { dev_dbg(dev, "%llu is not %ldK aligned\n", val, - (PAGE_SIZE * nd_region->ndr_mappings) / SZ_1K); + nd_region->align / SZ_1K); return -EINVAL; } diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h index 4a946c019e0f..e37c79c340d6 100644 --- a/drivers/nvdimm/nd.h +++ b/drivers/nvdimm/nd.h @@ -146,6 +146,7 @@ struct nd_region { struct device *btt_seed; struct device *pfn_seed; struct device *dax_seed; + unsigned long align; u16 ndr_mappings; u64 ndr_size; u64 ndr_start; diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c index b1b13debffbc..7d5ab00c7b45 100644 --- a/drivers/nvdimm/region_devs.c +++ b/drivers/nvdimm/region_devs.c @@ -246,21 +246,25 @@ int nd_region_to_nstype(struct nd_region *nd_region) } EXPORT_SYMBOL(nd_region_to_nstype); -static ssize_t size_show(struct device *dev, - struct device_attribute *attr, char *buf) +static unsigned long long region_size(struct nd_region *nd_region) { - struct nd_region *nd_region = to_nd_region(dev); - unsigned long long size = 0; - - if (is_memory(dev)) { - size = nd_region->ndr_size; + if (is_memory(&nd_region->dev)) { + return nd_region->ndr_size; } else if (nd_region->ndr_mappings == 1) { struct nd_mapping *nd_mapping = &nd_region->mapping[0]; - size = nd_mapping->size; + return nd_mapping->size; } - return sprintf(buf, "%llu\n", size); + return 0; +} + +static ssize_t size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct nd_region *nd_region = to_nd_region(dev); + + return sprintf(buf, "%llu\n", region_size(nd_region)); } static DEVICE_ATTR_RO(size); @@ -559,6 +563,54 @@ static ssize_t read_only_store(struct device *dev, } static DEVICE_ATTR_RW(read_only); +static ssize_t align_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct nd_region *nd_region = to_nd_region(dev); + + return sprintf(buf, "%#lx\n", nd_region->align); +} + +static ssize_t align_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t len) +{ + struct nd_region *nd_region = to_nd_region(dev); + unsigned long val, dpa; + u32 remainder; + int rc; + + rc = kstrtoul(buf, 0, &val); + if (rc) + return rc; + + if (!nd_region->ndr_mappings) + return -ENXIO; + + /* + * Ensure space-align is evenly divisible by the region + * interleave-width because the kernel typically has no facility + * to determine which DIMM(s), dimm-physical-addresses, would + * contribute to the tail capacity in system-physical-address + * space for the namespace. + */ + dpa = div_u64_rem(val, nd_region->ndr_mappings, &remainder); + if (!is_power_of_2(dpa) || dpa < PAGE_SIZE + || val > region_size(nd_region) || remainder) + return -EINVAL; + + /* + * Given that space allocation consults this value multiple + * times ensure it does not change for the duration of the + * allocation. + */ + nvdimm_bus_lock(dev); + nd_region->align = val; + nvdimm_bus_unlock(dev); + + return len; +} +static DEVICE_ATTR_RW(align); + static ssize_t region_badblocks_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -601,6 +653,7 @@ static DEVICE_ATTR_RO(persistence_domain); static struct attribute *nd_region_attributes[] = { &dev_attr_size.attr, + &dev_attr_align.attr, &dev_attr_nstype.attr, &dev_attr_mappings.attr, &dev_attr_btt_seed.attr, @@ -660,6 +713,19 @@ static umode_t region_visible(struct kobject *kobj, struct attribute *a, int n) return a->mode; } + if (a == &dev_attr_align.attr) { + int i; + + for (i = 0; i < nd_region->ndr_mappings; i++) { + struct nd_mapping *nd_mapping = &nd_region->mapping[i]; + struct nvdimm *nvdimm = nd_mapping->nvdimm; + + if (test_bit(NDD_LABELING, &nvdimm->flags)) + return a->mode; + } + return 0; + } + if (a != &dev_attr_set_cookie.attr && a != &dev_attr_available_size.attr) return a->mode; @@ -930,6 +996,41 @@ void nd_region_release_lane(struct nd_region *nd_region, unsigned int lane) } EXPORT_SYMBOL(nd_region_release_lane); +/* + * PowerPC requires this alignment for memremap_pages(). All other archs + * should be ok with SUBSECTION_SIZE (see memremap_compat_align()). + */ +#define MEMREMAP_COMPAT_ALIGN_MAX SZ_16M + +static unsigned long default_align(struct nd_region *nd_region) +{ + unsigned long align; + int i, mappings; + u32 remainder; + + if (is_nd_blk(&nd_region->dev)) + align = PAGE_SIZE; + else + align = MEMREMAP_COMPAT_ALIGN_MAX; + + for (i = 0; i < nd_region->ndr_mappings; i++) { + struct nd_mapping *nd_mapping = &nd_region->mapping[i]; + struct nvdimm *nvdimm = nd_mapping->nvdimm; + + if (test_bit(NDD_ALIASING, &nvdimm->flags)) { + align = MEMREMAP_COMPAT_ALIGN_MAX; + break; + } + } + + mappings = max_t(u16, 1, nd_region->ndr_mappings); + div_u64_rem(align, mappings, &remainder); + if (remainder) + align *= mappings; + + return align; +} + static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus, struct nd_region_desc *ndr_desc, struct device_type *dev_type, const char *caller) @@ -1034,6 +1135,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus, dev->of_node = ndr_desc->of_node; nd_region->ndr_size = resource_size(ndr_desc->res); nd_region->ndr_start = ndr_desc->res->start; + nd_region->align = default_align(nd_region); if (ndr_desc->flush) nd_region->flush = ndr_desc->flush; else
