| Message ID | 160106112239.30709.15909567572288425294.stgit@dwillia2-desk3.amr.corp.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | device-dax: support sub-dividing soft-reserved ranges | expand |
On 25.09.20 21:12, Dan Williams wrote: > Towards removing the mode specific @dax_kmem_res attribute from the > generic 'struct dev_dax', and preparing for multi-range support, change > the kmem driver to use the idiomatic release_mem_region() to pair with > the initial request_mem_region(). This also eliminates the need to open > code the release of the resource allocated by request_mem_region(). > > As there are no more dax_kmem_res users, delete this struct member. > > Cc: David Hildenbrand <david@redhat.com> > Cc: Vishal Verma <vishal.l.verma@intel.com> > Cc: Dave Hansen <dave.hansen@linux.intel.com> > Cc: Pavel Tatashin <pasha.tatashin@soleen.com> > Cc: Brice Goglin <Brice.Goglin@inria.fr> > Cc: Dave Jiang <dave.jiang@intel.com> > Cc: David Hildenbrand <david@redhat.com> > Cc: Ira Weiny <ira.weiny@intel.com> > Cc: Jia He <justin.he@arm.com> > Cc: Joao Martins <joao.m.martins@oracle.com> > Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > drivers/dax/dax-private.h | 3 --- > drivers/dax/kmem.c | 20 +++++++------------- > 2 files changed, 7 insertions(+), 16 deletions(-) > > diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h > index 6779f683671d..12a2dbc43b40 100644 > --- a/drivers/dax/dax-private.h > +++ b/drivers/dax/dax-private.h > @@ -42,8 +42,6 @@ struct dax_region { > * @dev - device core > * @pgmap - pgmap for memmap setup / lifetime (driver owned) > * @range: resource range for the instance > - * @dax_mem_res: physical address range of hotadded DAX memory > - * @dax_mem_name: name for hotadded DAX memory via add_memory_driver_managed() > */ > struct dev_dax { > struct dax_region *region; > @@ -52,7 +50,6 @@ struct dev_dax { > struct device dev; > struct dev_pagemap *pgmap; > struct range range; > - struct resource *dax_kmem_res; > }; > > static inline u64 range_len(struct range *range) > diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c > index 6fe2cb1c5f7c..e56fc688bdc5 100644 > --- a/drivers/dax/kmem.c > +++ b/drivers/dax/kmem.c > @@ -33,7 +33,7 @@ int dev_dax_kmem_probe(struct device *dev) > { > struct dev_dax *dev_dax = to_dev_dax(dev); > struct range range = dax_kmem_range(dev_dax); > - struct resource *new_res; > + struct resource *res; > char *res_name; > int numa_node; > int rc; > @@ -56,8 +56,8 @@ int dev_dax_kmem_probe(struct device *dev) > return -ENOMEM; > > /* Region is permanently reserved if hotremove fails. */ > - new_res = request_mem_region(range.start, range_len(&range), res_name); > - if (!new_res) { > + res = request_mem_region(range.start, range_len(&range), res_name); > + if (!res) { > dev_warn(dev, "could not reserve region [%#llx-%#llx]\n", range.start, range.end); > kfree(res_name); > return -EBUSY; > @@ -69,23 +69,20 @@ int dev_dax_kmem_probe(struct device *dev) > * inherit flags from the parent since it may set new flags > * unknown to us that will break add_memory() below. > */ > - new_res->flags = IORESOURCE_SYSTEM_RAM; > + res->flags = IORESOURCE_SYSTEM_RAM; > > /* > * Ensure that future kexec'd kernels will not treat this as RAM > * automatically. > */ > - rc = add_memory_driver_managed(numa_node, new_res->start, > - resource_size(new_res), kmem_name); > + rc = add_memory_driver_managed(numa_node, range.start, range_len(&range), kmem_name); > if (rc) { > - release_resource(new_res); > - kfree(new_res); > + release_mem_region(range.start, range_len(&range)); > kfree(res_name); > return rc; > } > > dev_set_drvdata(dev, res_name); > - dev_dax->dax_kmem_res = new_res; > > return 0; > } > @@ -95,7 +92,6 @@ static int dev_dax_kmem_remove(struct device *dev) > { > struct dev_dax *dev_dax = to_dev_dax(dev); > struct range range = dax_kmem_range(dev_dax); > - struct resource *res = dev_dax->dax_kmem_res; > const char *res_name = dev_get_drvdata(dev); > int rc; > > @@ -114,10 +110,8 @@ static int dev_dax_kmem_remove(struct device *dev) > } > > /* Release and free dax resources */ > - release_resource(res); > - kfree(res); > + release_mem_region(range.start, range_len(&range)); Does that work? AFAIKs, __release_region(&iomem_resource, (start), (n)) -> __release_region() will only remove stuff that is IORESOURCE_BUSY. Maybe storing it in drvdata is indeed the easiest way to remove it from struct dax_region.
On Wed, Sep 30, 2020 at 9:23 AM David Hildenbrand <david@redhat.com> wrote: > > On 25.09.20 21:12, Dan Williams wrote: > > Towards removing the mode specific @dax_kmem_res attribute from the > > generic 'struct dev_dax', and preparing for multi-range support, change > > the kmem driver to use the idiomatic release_mem_region() to pair with > > the initial request_mem_region(). This also eliminates the need to open > > code the release of the resource allocated by request_mem_region(). > > > > As there are no more dax_kmem_res users, delete this struct member. > > > > Cc: David Hildenbrand <david@redhat.com> > > Cc: Vishal Verma <vishal.l.verma@intel.com> > > Cc: Dave Hansen <dave.hansen@linux.intel.com> > > Cc: Pavel Tatashin <pasha.tatashin@soleen.com> > > Cc: Brice Goglin <Brice.Goglin@inria.fr> > > Cc: Dave Jiang <dave.jiang@intel.com> > > Cc: David Hildenbrand <david@redhat.com> > > Cc: Ira Weiny <ira.weiny@intel.com> > > Cc: Jia He <justin.he@arm.com> > > Cc: Joao Martins <joao.m.martins@oracle.com> > > Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> > > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > > --- > > drivers/dax/dax-private.h | 3 --- > > drivers/dax/kmem.c | 20 +++++++------------- > > 2 files changed, 7 insertions(+), 16 deletions(-) > > > > diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h > > index 6779f683671d..12a2dbc43b40 100644 > > --- a/drivers/dax/dax-private.h > > +++ b/drivers/dax/dax-private.h > > @@ -42,8 +42,6 @@ struct dax_region { > > * @dev - device core > > * @pgmap - pgmap for memmap setup / lifetime (driver owned) > > * @range: resource range for the instance > > - * @dax_mem_res: physical address range of hotadded DAX memory > > - * @dax_mem_name: name for hotadded DAX memory via add_memory_driver_managed() > > */ > > struct dev_dax { > > struct dax_region *region; > > @@ -52,7 +50,6 @@ struct dev_dax { > > struct device dev; > > struct dev_pagemap *pgmap; > > struct range range; > > - struct resource *dax_kmem_res; > > }; > > > > static inline u64 range_len(struct range *range) > > diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c > > index 6fe2cb1c5f7c..e56fc688bdc5 100644 > > --- a/drivers/dax/kmem.c > > +++ b/drivers/dax/kmem.c > > @@ -33,7 +33,7 @@ int dev_dax_kmem_probe(struct device *dev) > > { > > struct dev_dax *dev_dax = to_dev_dax(dev); > > struct range range = dax_kmem_range(dev_dax); > > - struct resource *new_res; > > + struct resource *res; > > char *res_name; > > int numa_node; > > int rc; > > @@ -56,8 +56,8 @@ int dev_dax_kmem_probe(struct device *dev) > > return -ENOMEM; > > > > /* Region is permanently reserved if hotremove fails. */ > > - new_res = request_mem_region(range.start, range_len(&range), res_name); > > - if (!new_res) { > > + res = request_mem_region(range.start, range_len(&range), res_name); > > + if (!res) { > > dev_warn(dev, "could not reserve region [%#llx-%#llx]\n", range.start, range.end); > > kfree(res_name); > > return -EBUSY; > > @@ -69,23 +69,20 @@ int dev_dax_kmem_probe(struct device *dev) > > * inherit flags from the parent since it may set new flags > > * unknown to us that will break add_memory() below. > > */ > > - new_res->flags = IORESOURCE_SYSTEM_RAM; > > + res->flags = IORESOURCE_SYSTEM_RAM; > > > > /* > > * Ensure that future kexec'd kernels will not treat this as RAM > > * automatically. > > */ > > - rc = add_memory_driver_managed(numa_node, new_res->start, > > - resource_size(new_res), kmem_name); > > + rc = add_memory_driver_managed(numa_node, range.start, range_len(&range), kmem_name); > > if (rc) { > > - release_resource(new_res); > > - kfree(new_res); > > + release_mem_region(range.start, range_len(&range)); > > kfree(res_name); > > return rc; > > } > > > > dev_set_drvdata(dev, res_name); > > - dev_dax->dax_kmem_res = new_res; > > > > return 0; > > } > > @@ -95,7 +92,6 @@ static int dev_dax_kmem_remove(struct device *dev) > > { > > struct dev_dax *dev_dax = to_dev_dax(dev); > > struct range range = dax_kmem_range(dev_dax); > > - struct resource *res = dev_dax->dax_kmem_res; > > const char *res_name = dev_get_drvdata(dev); > > int rc; > > > > @@ -114,10 +110,8 @@ static int dev_dax_kmem_remove(struct device *dev) > > } > > > > /* Release and free dax resources */ > > - release_resource(res); > > - kfree(res); > > + release_mem_region(range.start, range_len(&range)); > > Does that work? AFAIKs, > > __release_region(&iomem_resource, (start), (n)) -> __release_region() > > will only remove stuff that is IORESOURCE_BUSY. Oh, crud, indeed. More fallout from futzing with the flags. > Maybe storing it in drvdata is indeed the easiest way to remove it from > struct dax_region. My first choice is still to get the driver out of the layering violation of touching resource flags, but we don't seem to be converging on a way forward there. So, stuffing more tracking into drvdata (especially for the multi-range case) is the next best option.
diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h index 6779f683671d..12a2dbc43b40 100644 --- a/drivers/dax/dax-private.h +++ b/drivers/dax/dax-private.h @@ -42,8 +42,6 @@ struct dax_region { * @dev - device core * @pgmap - pgmap for memmap setup / lifetime (driver owned) * @range: resource range for the instance - * @dax_mem_res: physical address range of hotadded DAX memory - * @dax_mem_name: name for hotadded DAX memory via add_memory_driver_managed() */ struct dev_dax { struct dax_region *region; @@ -52,7 +50,6 @@ struct dev_dax { struct device dev; struct dev_pagemap *pgmap; struct range range; - struct resource *dax_kmem_res; }; static inline u64 range_len(struct range *range) diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c index 6fe2cb1c5f7c..e56fc688bdc5 100644 --- a/drivers/dax/kmem.c +++ b/drivers/dax/kmem.c @@ -33,7 +33,7 @@ int dev_dax_kmem_probe(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); struct range range = dax_kmem_range(dev_dax); - struct resource *new_res; + struct resource *res; char *res_name; int numa_node; int rc; @@ -56,8 +56,8 @@ int dev_dax_kmem_probe(struct device *dev) return -ENOMEM; /* Region is permanently reserved if hotremove fails. */ - new_res = request_mem_region(range.start, range_len(&range), res_name); - if (!new_res) { + res = request_mem_region(range.start, range_len(&range), res_name); + if (!res) { dev_warn(dev, "could not reserve region [%#llx-%#llx]\n", range.start, range.end); kfree(res_name); return -EBUSY; @@ -69,23 +69,20 @@ int dev_dax_kmem_probe(struct device *dev) * inherit flags from the parent since it may set new flags * unknown to us that will break add_memory() below. */ - new_res->flags = IORESOURCE_SYSTEM_RAM; + res->flags = IORESOURCE_SYSTEM_RAM; /* * Ensure that future kexec'd kernels will not treat this as RAM * automatically. */ - rc = add_memory_driver_managed(numa_node, new_res->start, - resource_size(new_res), kmem_name); + rc = add_memory_driver_managed(numa_node, range.start, range_len(&range), kmem_name); if (rc) { - release_resource(new_res); - kfree(new_res); + release_mem_region(range.start, range_len(&range)); kfree(res_name); return rc; } dev_set_drvdata(dev, res_name); - dev_dax->dax_kmem_res = new_res; return 0; } @@ -95,7 +92,6 @@ static int dev_dax_kmem_remove(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); struct range range = dax_kmem_range(dev_dax); - struct resource *res = dev_dax->dax_kmem_res; const char *res_name = dev_get_drvdata(dev); int rc; @@ -114,10 +110,8 @@ static int dev_dax_kmem_remove(struct device *dev) } /* Release and free dax resources */ - release_resource(res); - kfree(res); + release_mem_region(range.start, range_len(&range)); kfree(res_name); - dev_dax->dax_kmem_res = NULL; return 0; }
Towards removing the mode specific @dax_kmem_res attribute from the generic 'struct dev_dax', and preparing for multi-range support, change the kmem driver to use the idiomatic release_mem_region() to pair with the initial request_mem_region(). This also eliminates the need to open code the release of the resource allocated by request_mem_region(). As there are no more dax_kmem_res users, delete this struct member. Cc: David Hildenbrand <david@redhat.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Brice Goglin <Brice.Goglin@inria.fr> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jia He <justin.he@arm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> --- drivers/dax/dax-private.h | 3 --- drivers/dax/kmem.c | 20 +++++++------------- 2 files changed, 7 insertions(+), 16 deletions(-)