From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 46045223648BB for ; Tue, 30 Jan 2018 14:26:19 -0800 (PST) Date: Tue, 30 Jan 2018 15:31:54 -0700 From: Ross Zwisler Subject: Re: [PATCH v2 1/4] acpi: nfit: Add support for detect platform CPU cache flush on power loss Message-ID: <20180130223154.GA23836@linux.intel.com> References: <151276655874.31888.13113966406333561201.stgit@djiang5-desk3.ch.intel.com> <151276680927.31888.15096916678580860198.stgit@djiang5-desk3.ch.intel.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <151276680927.31888.15096916678580860198.stgit@djiang5-desk3.ch.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: Dave Jiang Cc: linux-nvdimm@lists.01.org List-ID: On Fri, Dec 08, 2017 at 02:00:09PM -0700, Dave Jiang wrote: > In ACPI 6.2a the platform capability structure has been added to the NFIT > tables. That provides software the ability to determine whether a system > supports the auto flushing of CPU caches on power loss. If the capability > is supported, we do not need to do dax_write_cache(). Plumbing the path dax_flush() ? dax_write_cache() just sets or clears DAXDEV_WRITE_CACHE. dax_flush() is the place where we check DAXDEV_WRITE_CACHE and avoid calling arch_wb_cache_pmem() if the platform supports a flush-on-fail CPU cache. > to set the property on per region from the NFTI tables. NFIT > > This patch depends on the ACPI NFIT 6.2a platform capabilities support code > in include/acpi/actbl1.h. > > Signed-off-by: Dave Jiang > --- > drivers/acpi/nfit/core.c | 20 ++++++++++++++++++++ > drivers/acpi/nfit/nfit.h | 1 + > drivers/nvdimm/pmem.c | 4 +++- > drivers/nvdimm/region_devs.c | 1 + > include/linux/libnvdimm.h | 5 +++++ > 5 files changed, 30 insertions(+), 1 deletion(-) > > diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c > index ff2580e7611d..c08b3da61b93 100644 > --- a/drivers/acpi/nfit/core.c > +++ b/drivers/acpi/nfit/core.c > @@ -838,6 +838,18 @@ static bool add_flush(struct acpi_nfit_desc *acpi_desc, > return true; > } > > +static bool add_platform_cap(struct acpi_nfit_desc *acpi_desc, > + struct acpi_nfit_capabilities *pcap) > +{ > + struct device *dev = acpi_desc->dev; > + u8 mask; 'mask' cannot be a u8, else you'll lose all the upper bits when you compute it. It needs to be a u32. > + > + mask = pcap->highest_capability - 1 + pcap->highest_capability; This calculation is broken. Take the simplest case, highest_capability = 0. This should translate into a mask of 0x1, so you only look at bit 0, but: 0 - 1 + 0 == -1 giving you a mask that includes all the bits. I think the mask you're looking for is: mask = (1 << (pcap->highest_capability + 1)) - 1; > + acpi_desc->platform_cap = pcap->capabilities & (u32)mask; > + dev_dbg(dev, "%s: cap: %#x\n", __func__, acpi_desc->platform_cap); > + return true; > +} > + > static void *add_table(struct acpi_nfit_desc *acpi_desc, > struct nfit_table_prev *prev, void *table, const void *end) > { <> > diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c > index 7fbc5c5dc8e1..13f2ed80899e 100644 > --- a/drivers/nvdimm/pmem.c > +++ b/drivers/nvdimm/pmem.c > @@ -35,6 +35,7 @@ > #include "pmem.h" > #include "pfn.h" > #include "nd.h" > +#include "nd-core.h" > > static struct device *to_dev(struct pmem_device *pmem) > { > @@ -334,7 +335,8 @@ static int pmem_attach_disk(struct device *dev, > dev_warn(dev, "unable to guarantee persistence of writes\n"); > fua = 0; > } > - wbc = nvdimm_has_cache(nd_region); > + wbc = nvdimm_has_cache(nd_region) & I'm guessing you meant: && > + !test_bit(ND_REGION_PERSIST_CACHE, &nd_region->flags); > > if (!devm_request_mem_region(dev, res->start, resource_size(res), > dev_name(&ndns->dev))) { > diff --git a/drivers/nvdimm/region_devs.c b/drivers/nvdimm/region_devs.c > index abaf38c61220..87e8cd10de05 100644 > --- a/drivers/nvdimm/region_devs.c > +++ b/drivers/nvdimm/region_devs.c > @@ -994,6 +994,7 @@ static struct nd_region *nd_region_create(struct nvdimm_bus *nvdimm_bus, > dev->groups = ndr_desc->attr_groups; > nd_region->ndr_size = resource_size(ndr_desc->res); > nd_region->ndr_start = ndr_desc->res->start; > + Unrelated whitespace change. > nd_device_register(dev); > > return nd_region; _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm