Expand the region creation infrastructure to enable 'ram' (volatile-memory) regions. The internals of create_pmem_region_store() and create_pmem_region_show() are factored out into helpers __create_region() and __create_region_show() for the 'ram' case to reuse. Reviewed-by: Vishal Verma <vishal.l.verma@xxxxxxxxx> Reviewed-by: Gregory Price <gregory.price@xxxxxxxxxxxx> Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx> Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Tested-by: Fan Ni <fan.ni@xxxxxxxxxxx> Link: https://lore.kernel.org/r/167564537678.847146.4066579806086171091.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> --- Documentation/ABI/testing/sysfs-bus-cxl | 22 +++++----- drivers/cxl/core/core.h | 1 drivers/cxl/core/port.c | 14 ++++++ drivers/cxl/core/region.c | 71 +++++++++++++++++++++++++------ 4 files changed, 83 insertions(+), 25 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-bus-cxl b/Documentation/ABI/testing/sysfs-bus-cxl index 4c4e1cbb1169..3acf2f17a73f 100644 --- a/Documentation/ABI/testing/sysfs-bus-cxl +++ b/Documentation/ABI/testing/sysfs-bus-cxl @@ -285,20 +285,20 @@ Description: interleave_granularity). -What: /sys/bus/cxl/devices/decoderX.Y/create_pmem_region -Date: May, 2022 -KernelVersion: v6.0 +What: /sys/bus/cxl/devices/decoderX.Y/create_{pmem,ram}_region +Date: May, 2022, January, 2023 +KernelVersion: v6.0 (pmem), v6.3 (ram) Contact: linux-cxl@xxxxxxxxxxxxxxx Description: (RW) Write a string in the form 'regionZ' to start the process - of defining a new persistent memory region (interleave-set) - within the decode range bounded by root decoder 'decoderX.Y'. - The value written must match the current value returned from - reading this attribute. An atomic compare exchange operation is - done on write to assign the requested id to a region and - allocate the region-id for the next creation attempt. EBUSY is - returned if the region name written does not match the current - cached value. + of defining a new persistent, or volatile memory region + (interleave-set) within the decode range bounded by root decoder + 'decoderX.Y'. The value written must match the current value + returned from reading this attribute. An atomic compare exchange + operation is done on write to assign the requested id to a + region and allocate the region-id for the next creation attempt. + EBUSY is returned if the region name written does not match the + current cached value. What: /sys/bus/cxl/devices/decoderX.Y/delete_region diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h index 8c04672dca56..5eb873da5a30 100644 --- a/drivers/cxl/core/core.h +++ b/drivers/cxl/core/core.h @@ -11,6 +11,7 @@ extern struct attribute_group cxl_base_attribute_group; #ifdef CONFIG_CXL_REGION extern struct device_attribute dev_attr_create_pmem_region; +extern struct device_attribute dev_attr_create_ram_region; extern struct device_attribute dev_attr_delete_region; extern struct device_attribute dev_attr_region; extern const struct device_type cxl_pmem_region_type; diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c index 1e541956f605..9e5df64ea6b5 100644 --- a/drivers/cxl/core/port.c +++ b/drivers/cxl/core/port.c @@ -294,6 +294,7 @@ static struct attribute *cxl_decoder_root_attrs[] = { &dev_attr_cap_type3.attr, &dev_attr_target_list.attr, SET_CXL_REGION_ATTR(create_pmem_region) + SET_CXL_REGION_ATTR(create_ram_region) SET_CXL_REGION_ATTR(delete_region) NULL, }; @@ -305,6 +306,13 @@ static bool can_create_pmem(struct cxl_root_decoder *cxlrd) return (cxlrd->cxlsd.cxld.flags & flags) == flags; } +static bool can_create_ram(struct cxl_root_decoder *cxlrd) +{ + unsigned long flags = CXL_DECODER_F_TYPE3 | CXL_DECODER_F_RAM; + + return (cxlrd->cxlsd.cxld.flags & flags) == flags; +} + static umode_t cxl_root_decoder_visible(struct kobject *kobj, struct attribute *a, int n) { struct device *dev = kobj_to_dev(kobj); @@ -313,7 +321,11 @@ static umode_t cxl_root_decoder_visible(struct kobject *kobj, struct attribute * if (a == CXL_REGION_ATTR(create_pmem_region) && !can_create_pmem(cxlrd)) return 0; - if (a == CXL_REGION_ATTR(delete_region) && !can_create_pmem(cxlrd)) + if (a == CXL_REGION_ATTR(create_ram_region) && !can_create_ram(cxlrd)) + return 0; + + if (a == CXL_REGION_ATTR(delete_region) && + !(can_create_pmem(cxlrd) || can_create_ram(cxlrd))) return 0; return a->mode; diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 285835145e9b..e440db8611a4 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -1689,6 +1689,15 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd, struct device *dev; int rc; + switch (mode) { + case CXL_DECODER_RAM: + case CXL_DECODER_PMEM: + break; + default: + dev_err(&cxlrd->cxlsd.cxld.dev, "unsupported mode %d\n", mode); + return ERR_PTR(-EINVAL); + } + cxlr = cxl_region_alloc(cxlrd, id); if (IS_ERR(cxlr)) return cxlr; @@ -1717,12 +1726,38 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd, return ERR_PTR(rc); } +static ssize_t __create_region_show(struct cxl_root_decoder *cxlrd, char *buf) +{ + return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id)); +} + static ssize_t create_pmem_region_show(struct device *dev, struct device_attribute *attr, char *buf) { - struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev); + return __create_region_show(to_cxl_root_decoder(dev), buf); +} - return sysfs_emit(buf, "region%u\n", atomic_read(&cxlrd->region_id)); +static ssize_t create_ram_region_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return __create_region_show(to_cxl_root_decoder(dev), buf); +} + +static struct cxl_region *__create_region(struct cxl_root_decoder *cxlrd, + enum cxl_decoder_mode mode, int id) +{ + int rc; + + rc = memregion_alloc(GFP_KERNEL); + if (rc < 0) + return ERR_PTR(rc); + + if (atomic_cmpxchg(&cxlrd->region_id, id, rc) != id) { + memregion_free(rc); + return ERR_PTR(-EBUSY); + } + + return devm_cxl_add_region(cxlrd, id, mode, CXL_DECODER_EXPANDER); } static ssize_t create_pmem_region_store(struct device *dev, @@ -1731,29 +1766,39 @@ static ssize_t create_pmem_region_store(struct device *dev, { struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev); struct cxl_region *cxlr; - int id, rc; + int rc, id; rc = sscanf(buf, "region%d\n", &id); if (rc != 1) return -EINVAL; - rc = memregion_alloc(GFP_KERNEL); - if (rc < 0) - return rc; + cxlr = __create_region(cxlrd, CXL_DECODER_PMEM, id); + if (IS_ERR(cxlr)) + return PTR_ERR(cxlr); - if (atomic_cmpxchg(&cxlrd->region_id, id, rc) != id) { - memregion_free(rc); - return -EBUSY; - } + return len; +} +DEVICE_ATTR_RW(create_pmem_region); + +static ssize_t create_ram_region_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev); + struct cxl_region *cxlr; + int rc, id; - cxlr = devm_cxl_add_region(cxlrd, id, CXL_DECODER_PMEM, - CXL_DECODER_EXPANDER); + rc = sscanf(buf, "region%d\n", &id); + if (rc != 1) + return -EINVAL; + + cxlr = __create_region(cxlrd, CXL_DECODER_RAM, id); if (IS_ERR(cxlr)) return PTR_ERR(cxlr); return len; } -DEVICE_ATTR_RW(create_pmem_region); +DEVICE_ATTR_RW(create_ram_region); static ssize_t region_show(struct device *dev, struct device_attribute *attr, char *buf)
