Messages in this thread | | | Date | Wed, 30 Aug 2023 15:46:00 -0700 | Subject | Re: [PATCH RFC v2 07/18] cxl/mem: Expose device dynamic capacity configuration | From | Dave Jiang <> |
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On 8/28/23 22:20, ira.weiny@intel.com wrote: > From: Navneet Singh <navneet.singh@intel.com> > > To properly configure CXL regions on Dynamic Capacity Devices (DCD), > user space will need to know the details of the DC Regions available on > a device. > > Expose driver dynamic capacity configuration through sysfs > attributes. > > Co-developed-by: Navneet Singh <navneet.singh@intel.com> > Signed-off-by: Navneet Singh <navneet.singh@intel.com> > Signed-off-by: Ira Weiny <ira.weiny@intel.com> > > --- > Changes for v2: > [iweiny: Rebased on latest master/type2 work] > [iweiny: add documentation for sysfs entries] > [iweiny: s/dc_regions_count/region_count/] > [iweiny: s/dcY_size/regionY_size/] > [alison: change size format to %#llx] > [iweiny: change count format to %d] > [iweiny: Formatting updates] > [iweiny: Fix crash when device is not a mem device: found with cxl-test] > --- > Documentation/ABI/testing/sysfs-bus-cxl | 17 ++++++++ > drivers/cxl/core/memdev.c | 77 +++++++++++++++++++++++++++++++++ > 2 files changed, 94 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl > index 2268ffcdb604..aa65dc5b4e13 100644 > --- a/Documentation/ABI/testing/sysfs-bus-cxl > +++ b/Documentation/ABI/testing/sysfs-bus-cxl > @@ -37,6 +37,23 @@ Description: > identically named field in the Identify Memory Device Output > Payload in the CXL-2.0 specification. > > +What: /sys/bus/cxl/devices/memX/dc/region_count > +Date: July, 2023 > +KernelVersion: v6.6 > +Contact: linux-cxl@vger.kernel.org > +Description: > + (RO) Number of Dynamic Capacity (DC) regions supported on the > + device. May be 0 if the device does not support Dynamic > + Capacity. > + > +What: /sys/bus/cxl/devices/memX/dc/regionY_size > +Date: July, 2023 > +KernelVersion: v6.6 > +Contact: linux-cxl@vger.kernel.org > +Description: > + (RO) Size of the Dynamic Capacity (DC) region Y. Only > + available on devices which support DC and only for those > + region indexes supported by the device. > > What: /sys/bus/cxl/devices/memX/serial > Date: January, 2022 > diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c > index 492486707fd0..397262e0ebd2 100644 > --- a/drivers/cxl/core/memdev.c > +++ b/drivers/cxl/core/memdev.c > @@ -101,6 +101,20 @@ static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr, > static struct device_attribute dev_attr_pmem_size = > __ATTR(size, 0444, pmem_size_show, NULL); > > +static ssize_t region_count_show(struct device *dev, struct device_attribute *attr, > + char *buf) > +{ > + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); > + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds); > + int len = 0; > + > + len = sysfs_emit(buf, "%d\n", mds->nr_dc_region); > + return len; > +} > + > +struct device_attribute dev_attr_region_count = > + __ATTR(region_count, 0444, region_count_show, NULL); > + > static ssize_t serial_show(struct device *dev, struct device_attribute *attr, > char *buf) > { > @@ -454,6 +468,62 @@ static struct attribute *cxl_memdev_security_attributes[] = { > NULL, > }; > > +static ssize_t show_size_regionN(struct cxl_memdev *cxlmd, char *buf, int pos) > +{ > + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds); > + > + return sysfs_emit(buf, "%#llx\n", mds->dc_region[pos].decode_len); > +} > + > +#define REGION_SIZE_ATTR_RO(n) \ > +static ssize_t region##n##_size_show(struct device *dev, \ > + struct device_attribute *attr, \ > + char *buf) \ > +{ \ > + return show_size_regionN(to_cxl_memdev(dev), buf, (n)); \ > +} \ > +static DEVICE_ATTR_RO(region##n##_size) > +REGION_SIZE_ATTR_RO(0); > +REGION_SIZE_ATTR_RO(1); > +REGION_SIZE_ATTR_RO(2); > +REGION_SIZE_ATTR_RO(3); > +REGION_SIZE_ATTR_RO(4); > +REGION_SIZE_ATTR_RO(5); > +REGION_SIZE_ATTR_RO(6); > +REGION_SIZE_ATTR_RO(7); > + > +static struct attribute *cxl_memdev_dc_attributes[] = { > + &dev_attr_region0_size.attr, > + &dev_attr_region1_size.attr, > + &dev_attr_region2_size.attr, > + &dev_attr_region3_size.attr, > + &dev_attr_region4_size.attr, > + &dev_attr_region5_size.attr, > + &dev_attr_region6_size.attr, > + &dev_attr_region7_size.attr, > + &dev_attr_region_count.attr, > + NULL, > +}; > + > +static umode_t cxl_dc_visible(struct kobject *kobj, struct attribute *a, int n) > +{ > + struct device *dev = kobj_to_dev(kobj); > + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); > + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds); > + > + /* Not a memory device */ > + if (!mds) > + return 0; > + > + if (a == &dev_attr_region_count.attr) > + return a->mode; > + > + if (n < mds->nr_dc_region) > + return a->mode;
I would add a comment on who you are checking against nr_dc_region to make it obvious.
DJ
> + > + return 0; > +} > + > static umode_t cxl_memdev_visible(struct kobject *kobj, struct attribute *a, > int n) > { > @@ -482,11 +552,18 @@ static struct attribute_group cxl_memdev_security_attribute_group = { > .attrs = cxl_memdev_security_attributes, > }; > > +static struct attribute_group cxl_memdev_dc_attribute_group = { > + .name = "dc", > + .attrs = cxl_memdev_dc_attributes, > + .is_visible = cxl_dc_visible, > +}; > + > static const struct attribute_group *cxl_memdev_attribute_groups[] = { > &cxl_memdev_attribute_group, > &cxl_memdev_ram_attribute_group, > &cxl_memdev_pmem_attribute_group, > &cxl_memdev_security_attribute_group, > + &cxl_memdev_dc_attribute_group, > NULL, > }; > >
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