On Mon, 07 Oct 2024 18:16:19 -0500 ira.weiny@xxxxxxxxx wrote: > From: Navneet Singh <navneet.singh@xxxxxxxxx> > > To properly configure CXL regions on Dynamic Capacity Devices (DCD), > user space will need to know the details of the DC partitions available. > > Expose dynamic capacity capabilities through sysfs. > > Signed-off-by: Navneet Singh <navneet.singh@xxxxxxxxx> > Co-developed-by: Ira Weiny <ira.weiny@xxxxxxxxx> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> Some trivial stuff inline that I'm not that bothered about either way. Subject to answering Fan's query Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > > --- > Changes: > [iweiny: Change .../memX/dc/* to .../memX/dcY/*] > [iweiny: add read only and shareable attributes from DSMAS] > [djiang: Split sysfs docs] > [iweiny: Adjust sysfs doc dates] > [iweiny: Add qos details] > --- > Documentation/ABI/testing/sysfs-bus-cxl | 45 ++++++++++++ > drivers/cxl/core/memdev.c | 126 ++++++++++++++++++++++++++++++++ > 2 files changed, 171 insertions(+) > > diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl > index 3f5627a1210a..b865eefdb74c 100644 > --- a/Documentation/ABI/testing/sysfs-bus-cxl > +++ b/Documentation/ABI/testing/sysfs-bus-cxl > @@ -54,6 +54,51 @@ Description: > identically named field in the Identify Memory Device Output > Payload in the CXL-2.0 specification. > > +What: /sys/bus/cxl/devices/memX/dcY/size > +Date: December, 2024 > +KernelVersion: v6.13 > +Contact: linux-cxl@xxxxxxxxxxxxxxx > +Description: > + (RO) Dynamic Capacity (DC) region information. Devices only > + export dcY if DCD partition Y is supported. > + dcY/size is the size of each of those partitions. > + > +What: /sys/bus/cxl/devices/memX/dcY/read_only > +Date: December, 2024 > +KernelVersion: v6.13 > +Contact: linux-cxl@xxxxxxxxxxxxxxx > +Description: > + (RO) Dynamic Capacity (DC) region information. Devices only > + export dcY if DCD partition Y is supported. > + dcY/read_only indicates true if the region is exported > + read_only from the device. > + > +What: /sys/bus/cxl/devices/memX/dcY/shareable > +Date: December, 2024 > +KernelVersion: v6.13 > +Contact: linux-cxl@xxxxxxxxxxxxxxx > +Description: > + (RO) Dynamic Capacity (DC) region information. Devices only > + export dcY if DCD partition Y is supported. > + dcY/shareable indicates true if the region is exported > + shareable from the device. > + > +What: /sys/bus/cxl/devices/memX/dcY/qos_class > +Date: December, 2024 > +KernelVersion: v6.13 > +Contact: linux-cxl@xxxxxxxxxxxxxxx > +Description: > + (RO) Dynamic Capacity (DC) region information. Devices only > + export dcY if DCD partition Y is supported. You can document sysfs directories I think, e.g. https://elixir.bootlin.com/linux/v6.12-rc2/source/Documentation/ABI/stable/sysfs-devices-node#L32 so maybe What: /sys/bus/cxl/device/memX/dcY Date: December, 2024 KernelVersion: v6.13 Contact: linux-cxl@xxxxxxxxxxxxxxx Description: Directory containing Dynamic Capacity (DC) region information. Devices only export dcY if DCD partition Y is supported. What: /sys/bus/cxl/devices/memX/dcY/qos_class Date: December, 2024 KernelVersion: v6.13 Contact: linux-cxl@xxxxxxxxxxxxxxx Description: For CXL host... To avoid the repetition of first bit of docs? > + platforms that support "QoS Telemmetry" this attribute conveys > + a comma delimited list of platform specific cookies that > + identifies a QoS performance class for the persistent partition > + of the CXL mem device. These class-ids can be compared against > + a similar "qos_class" published for a root decoder. While it is > + not required that the endpoints map their local memory-class to > + a matching platform class, mismatches are not recommended and > + there are platform specific performance related side-effects > + that may result. First class-id is displayed. > > What: /sys/bus/cxl/devices/memX/pmem/qos_class > Date: May, 2023 > +static ssize_t show_shareable_dcN(struct cxl_memdev *cxlmd, char *buf, int pos) > +{ > + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds); > + > + return sysfs_emit(buf, "%s\n", > + str_false_true(mds->dc_region[pos].shareable)); Fan has already raised that these seem backwards. > +} > + > +static ssize_t show_qos_class_dcN(struct cxl_memdev *cxlmd, char *buf, int pos) > +{ > + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlmd->cxlds); > + > + return sysfs_emit(buf, "%d\n", mds->dc_perf[pos].qos_class); > +} > + > +#define CXL_MEMDEV_DC_ATTR_GROUP(n) \ > +static ssize_t dc##n##_size_show(struct device *dev, \ > + struct device_attribute *attr, \ > + char *buf) \ > +{ \ > + return show_size_dcN(to_cxl_memdev(dev), buf, (n)); \ > +} \ > +struct device_attribute dc##n##_size = { \ > + .attr = { .name = "size", .mode = 0444 }, \ > + .show = dc##n##_size_show, \ > +}; \ > +static ssize_t dc##n##_read_only_show(struct device *dev, \ > + struct device_attribute *attr, \ > + char *buf) \ > +{ \ > + return show_read_only_dcN(to_cxl_memdev(dev), buf, (n)); \ > +} \ > +struct device_attribute dc##n##_read_only = { \ > + .attr = { .name = "read_only", .mode = 0444 }, \ > + .show = dc##n##_read_only_show, \ > +}; \ > +static ssize_t dc##n##_shareable_show(struct device *dev, \ > + struct device_attribute *attr, \ > + char *buf) \ > +{ \ > + return show_shareable_dcN(to_cxl_memdev(dev), buf, (n)); \ > +} \ > +struct device_attribute dc##n##_shareable = { \ > + .attr = { .name = "shareable", .mode = 0444 }, \ > + .show = dc##n##_shareable_show, \ > +}; \ > +static ssize_t dc##n##_qos_class_show(struct device *dev, \ > + struct device_attribute *attr, \ > + char *buf) \ > +{ \ > + return show_qos_class_dcN(to_cxl_memdev(dev), buf, (n)); \ > +} \ > +struct device_attribute dc##n##_qos_class = { \ > + .attr = { .name = "qos_class", .mode = 0444 }, \ > + .show = dc##n##_qos_class_show, \ > +}; \ > +static struct attribute *cxl_memdev_dc##n##_attributes[] = { \ > + &dc##n##_size.attr, \ > + &dc##n##_read_only.attr, \ > + &dc##n##_shareable.attr, \ > + &dc##n##_qos_class.attr, \ > + NULL, \ No comma needed on terminator. > +}; \ > +static umode_t cxl_memdev_dc##n##_attr_visible(struct kobject *kobj, \ > + struct attribute *a, \ > + int pos) \ > +{ \ > + 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) \ if (!to_cxl_memdev_state(cxlmd->cxlds)) return 0; I dislike long macros so if we can shave them down that is always good! We do have precedence in hdm.c for just checking the type directly so maybe if (cxlmd->cxlds->type != CXL_DEVTYPE_CLASSMEM) but the above is also fine as compiler should be able to figure out it doesn't need to do the second half of the inline. > + return 0; \ > + return a->mode; \ > +} \ > +static umode_t cxl_memdev_dc##n##_group_visible(struct kobject *kobj) \ > +{ \ > + 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 or partition not supported */ \ > + if (!mds || n >= mds->nr_dc_region) \ > + return false; \ > + return true; \ /* Memory device and partition is supported */ return mds && n < mds->nr_dc_region; > +} \ >
