From 42834b17cf1f00fa79ff1f02134f9c576a125252 Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 21 Dec 2023 15:04:16 -0700 Subject: cxl: Export sysfs attributes for memory device QoS class Export qos_class sysfs attributes for the CXL memory device. The QoS clas should show up as /sys/bus/cxl/devices/memX/ram/qos_class for the volatile partition and /sys/bus/cxl/devices/memX/pmem/qos_class for the persistent partition. The QTG ID is retrieved via _DSM after supplying the calculated bandwidth and latency for the entire CXL path from device to the CPU. This ID is used to match up to the root decoder QoS class to determine which CFMWS the memory range of a hotplugged CXL mem device should be assigned under. While there may be multiple DSMAS exported by the device CDAT, the driver will only expose the first QTG ID per partition in sysfs for now. In the future when multiple QTG IDs are necessary, they can be exposed. [1] [1]: https://lore.kernel.org/linux-cxl/167571650007.587790.10040913293130712882.stgit@djiang5-mobl3.local/T/#md2a47b1ead3e1ba08f50eab29a4af1aed1d215ab Suggested-by: Dan Williams Reviewed-by: Jonathan Cameron Signed-off-by: Dave Jiang Link: https://lore.kernel.org/r/170319625698.2212653.17544381274847420961.stgit@djiang5-mobl3 Signed-off-by: Dan Williams --- drivers/cxl/mem.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 61 insertions(+), 6 deletions(-) (limited to 'drivers/cxl') diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c index e087febf9af0..c5c9d8e0d88d 100644 --- a/drivers/cxl/mem.c +++ b/drivers/cxl/mem.c @@ -215,23 +215,78 @@ static ssize_t trigger_poison_list_store(struct device *dev, } static DEVICE_ATTR_WO(trigger_poison_list); +static ssize_t ram_qos_class_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds); + struct cxl_dpa_perf *dpa_perf; + + if (!dev->driver) + return -ENOENT; + + if (list_empty(&mds->ram_perf_list)) + return -ENOENT; + + dpa_perf = list_first_entry(&mds->ram_perf_list, struct cxl_dpa_perf, + list); + + return sysfs_emit(buf, "%d\n", dpa_perf->qos_class); +} + +static struct device_attribute dev_attr_ram_qos_class = + __ATTR(qos_class, 0444, ram_qos_class_show, NULL); + +static ssize_t pmem_qos_class_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct cxl_memdev *cxlmd = to_cxl_memdev(dev); + struct cxl_dev_state *cxlds = cxlmd->cxlds; + struct cxl_memdev_state *mds = to_cxl_memdev_state(cxlds); + struct cxl_dpa_perf *dpa_perf; + + if (!dev->driver) + return -ENOENT; + + if (list_empty(&mds->pmem_perf_list)) + return -ENOENT; + + dpa_perf = list_first_entry(&mds->pmem_perf_list, struct cxl_dpa_perf, + list); + + return sysfs_emit(buf, "%d\n", dpa_perf->qos_class); +} + +static struct device_attribute dev_attr_pmem_qos_class = + __ATTR(qos_class, 0444, pmem_qos_class_show, NULL); + static umode_t cxl_mem_visible(struct kobject *kobj, struct attribute *a, int n) { - if (a == &dev_attr_trigger_poison_list.attr) { - 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); + 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); + if (a == &dev_attr_trigger_poison_list.attr) if (!test_bit(CXL_POISON_ENABLED_LIST, mds->poison.enabled_cmds)) return 0; - } + + if (a == &dev_attr_pmem_qos_class.attr) + if (list_empty(&mds->pmem_perf_list)) + return 0; + + if (a == &dev_attr_ram_qos_class.attr) + if (list_empty(&mds->ram_perf_list)) + return 0; + return a->mode; } static struct attribute *cxl_mem_attrs[] = { &dev_attr_trigger_poison_list.attr, + &dev_attr_ram_qos_class.attr, + &dev_attr_pmem_qos_class.attr, NULL }; -- cgit