From a15797f4bef201544263ef5c264c3f48d78cc5d4 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 31 Aug 2017 12:53:36 -0700 Subject: [PATCH] libnvdimm, nfit: export an 'ecc_unit_size' sysfs attribute When the nfit driver initializes it runs an ARS (Address Range Scrub) operation across every pmem range. Part of that process involves determining the ARS capabilities of a given address range. One of the capabilities that is reported is the 'Clear Uncorrectable Error Range Length Unit Size' (see: ACPI 6.2 section 9.20.7.4 Function Index 1 - Query ARS Capabilities). This property is of interest to userspace software as it indicates the boundary at which the NVDIMM may need to perform read-modify-write cycles to maintain ECC blocks. Cc: Vishal Verma Signed-off-by: Dan Williams --- drivers/acpi/nfit/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c index 2c5608b92578..03105648f9b1 100644 --- a/drivers/acpi/nfit/core.c +++ b/drivers/acpi/nfit/core.c @@ -1674,8 +1674,19 @@ static ssize_t range_index_show(struct device *dev, } static DEVICE_ATTR_RO(range_index); +static ssize_t ecc_unit_size_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct nd_region *nd_region = to_nd_region(dev); + struct nfit_spa *nfit_spa = nd_region_provider_data(nd_region); + + return sprintf(buf, "%d\n", nfit_spa->clear_err_unit); +} +static DEVICE_ATTR_RO(ecc_unit_size); + static struct attribute *acpi_nfit_region_attributes[] = { &dev_attr_range_index.attr, + &dev_attr_ecc_unit_size.attr, NULL, }; -- 2.20.1