On 10/24/19 7:36 AM, Dan Williams wrote:
On Thu, Oct 17, 2019 at 12:33 AM Aneesh Kumar K.V <[email protected]> wrote:nvdimm core currently maps the full namespace to an ioremap range while probing the namespace mode. This can result in probe failures on architectures that have limited ioremap space. For example, with a large btt namespace that consumes most of I/O remap range, depending on the sequence of namespace initialization, the user can find a pfn namespace initialization failure due to unavailable I/O remap space which nvdimm core uses for temporary mapping. nvdimm core can avoid this failure by only mapping the reserver block area tos/reserver/reserved/
Will fix
check for pfn superblock type and map the full namespace resource only before using the namespace.Are you going to follow up with the BTT patch that uses this new facility?
I am not yet sure about that. ioremap/vmap area is the way we get a kernel mapping without struct page backing. What we are suggesting hee is the ability to have a direct mapped mapping without struct page. I need to look at closely about what that imply.
Signed-off-by: Aneesh Kumar K.V <[email protected]> --- Changes from v2: * update changelog Changes from V1: * update changelog * update patch based on review feedback. drivers/dax/pmem/core.c | 2 +- drivers/nvdimm/claim.c | 7 +++---- drivers/nvdimm/nd.h | 4 ++-- drivers/nvdimm/pfn.h | 6 ++++++ drivers/nvdimm/pfn_devs.c | 5 ----- drivers/nvdimm/pmem.c | 15 ++++++++++++--- 6 files changed, 24 insertions(+), 15 deletions(-) diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c index 6eb6dfdf19bf..f174dbfbe1c4 100644 --- a/drivers/dax/pmem/core.c +++ b/drivers/dax/pmem/core.c @@ -28,7 +28,7 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys) nsio = to_nd_namespace_io(&ndns->dev); /* parse the 'pfn' info block via ->rw_bytes */ - rc = devm_nsio_enable(dev, nsio); + rc = devm_nsio_enable(dev, nsio, info_block_reserve()); if (rc) return ERR_PTR(rc); rc = nvdimm_setup_pfn(nd_pfn, &pgmap); diff --git a/drivers/nvdimm/claim.c b/drivers/nvdimm/claim.c index 2985ca949912..d89d2c039e25 100644 --- a/drivers/nvdimm/claim.c +++ b/drivers/nvdimm/claim.c @@ -300,12 +300,12 @@ static int nsio_rw_bytes(struct nd_namespace_common *ndns, return rc; } -int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio) +int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio, unsigned long size) { struct resource *res = &nsio->res; struct nd_namespace_common *ndns = &nsio->common; - nsio->size = resource_size(res); + nsio->size = size;This needs a: if (nsio->size) devm_memunmap(dev, nsio->addr);
Why ? we should not be calling devm_nsio_enable twice now.
if (!devm_request_mem_region(dev, res->start, resource_size(res), dev_name(&ndns->dev))) {Also don't repeat the devm_request_mem_region() if one was already done. Another thing to check is if nsio->size gets cleared when the namespace is disabled, if not that well need to be added in the shutdown path.
Not sure I understand that. So with this patch when we probe we always use info_block_reserve() size irrespective of the device. This probe will result in us adding a btt/pfn/dax device and we return -ENXIO after this probe. This return value will cause us to destroy the I/O remap mmapping we did with info_block_reserve() size. Also the nsio data structure is also freed.
nd_pmem_probe is then again called with btt device type and in that case we do devm_memremap again.
if (btt)
remap the full namespace size.
else
remap the info_block_reserve_size.
This infor block reserve mapping is unmapped in pmem_attach_disk()
Anything i am missing in the above flow?
dev_warn(dev, "could not reserve region %pR\n", res); @@ -318,8 +318,7 @@ int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio) nvdimm_badblocks_populate(to_nd_region(ndns->dev.parent), &nsio->bb, &nsio->res); - nsio->addr = devm_memremap(dev, res->start, resource_size(res), - ARCH_MEMREMAP_PMEM); + nsio->addr = devm_memremap(dev, res->start, size, ARCH_MEMREMAP_PMEM); return PTR_ERR_OR_ZERO(nsio->addr); } diff --git a/drivers/nvdimm/nd.h b/drivers/nvdimm/nd.h index ee5c04070ef9..93d3c760c0f3 100644 --- a/drivers/nvdimm/nd.h +++ b/drivers/nvdimm/nd.h @@ -376,7 +376,7 @@ void nvdimm_badblocks_populate(struct nd_region *nd_region, #define MAX_STRUCT_PAGE_SIZE 64 int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap); -int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio); +int devm_nsio_enable(struct device *dev, struct nd_namespace_io *nsio, unsigned long size); void devm_nsio_disable(struct device *dev, struct nd_namespace_io *nsio); #else static inline int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, @@ -385,7 +385,7 @@ static inline int nvdimm_setup_pfn(struct nd_pfn *nd_pfn, return -ENXIO; } static inline int devm_nsio_enable(struct device *dev, - struct nd_namespace_io *nsio) + struct nd_namespace_io *nsio, unsigned long size) { return -ENXIO; } diff --git a/drivers/nvdimm/pfn.h b/drivers/nvdimm/pfn.h index acb19517f678..f4856c87d01c 100644 --- a/drivers/nvdimm/pfn.h +++ b/drivers/nvdimm/pfn.h @@ -36,4 +36,10 @@ struct nd_pfn_sb { __le64 checksum; }; +static inline u32 info_block_reserve(void) +{ + return ALIGN(SZ_8K, PAGE_SIZE); +} + + #endif /* __NVDIMM_PFN_H */ diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c index 60d81fae06ee..e49aa9a0fd04 100644 --- a/drivers/nvdimm/pfn_devs.c +++ b/drivers/nvdimm/pfn_devs.c @@ -635,11 +635,6 @@ int nd_pfn_probe(struct device *dev, struct nd_namespace_common *ndns) } EXPORT_SYMBOL(nd_pfn_probe); -static u32 info_block_reserve(void) -{ - return ALIGN(SZ_8K, PAGE_SIZE); -} - /* * We hotplug memory at sub-section granularity, pad the reserved area * from the previous section base to the namespace base address. diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index f9f76f6ba07b..3c188ffeff11 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -491,17 +491,26 @@ static int pmem_attach_disk(struct device *dev, static int nd_pmem_probe(struct device *dev) { int ret; + struct nd_namespace_io *nsio; struct nd_namespace_common *ndns; ndns = nvdimm_namespace_common_probe(dev); if (IS_ERR(ndns)) return PTR_ERR(ndns); - if (devm_nsio_enable(dev, to_nd_namespace_io(&ndns->dev))) - return -ENXIO; + nsio = to_nd_namespace_io(&ndns->dev); - if (is_nd_btt(dev)) + if (is_nd_btt(dev)) { + /* + * Map with resource size + */ + if (devm_nsio_enable(dev, nsio, resource_size(&nsio->res))) + return -ENXIO; return nvdimm_namespace_attach_btt(ndns); + } + + if (devm_nsio_enable(dev, nsio, info_block_reserve())) + return -ENXIO; if (is_nd_pfn(dev)) return pmem_attach_disk(dev, ndns); -- 2.21.0
_______________________________________________ Linux-nvdimm mailing list -- [email protected] To unsubscribe send an email to [email protected]
