From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) (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 BF904202E5483 for ; Wed, 18 Jul 2018 10:41:21 -0700 (PDT) Subject: Re: [PATCH v5 09/12] nfit/libnvdimm: add support for issue secure erase DSM to Intel nvdimm References: <153186061802.27463.14539931103401173743.stgit@djiang5-desk3.ch.intel.com> <153186089522.27463.4537738384176593789.stgit@djiang5-desk3.ch.intel.com> From: Dave Jiang Message-ID: Date: Wed, 18 Jul 2018 10:41:20 -0700 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US 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: "Elliott, Robert (Persistent Memory)" , "Williams, Dan J" Cc: "dhowells@redhat.com" , "Schofield, Alison , keyrings@vger.kernel.org" , "keescook@chromium.org" , "linux-nvdimm@lists.01.org" List-ID: On 07/18/2018 10:27 AM, Elliott, Robert (Persistent Memory) wrote: > > >> -----Original Message----- >> From: Linux-nvdimm [mailto:linux-nvdimm-bounces@lists.01.org] On Behalf Of Dave Jiang >> Sent: Tuesday, July 17, 2018 3:55 PM >> Subject: [PATCH v5 09/12] nfit/libnvdimm: add support for issue secure erase DSM to Intel nvdimm > ... > +static int intel_dimm_security_erase(struct nvdimm_bus *nvdimm_bus, >> +struct nvdimm *nvdimm, struct nvdimm_key_data *nkey) > ... >> +/* DIMM unlocked, invalidate all CPU caches before we read it */ >> +wbinvd_on_all_cpus(); > > For this function, that comment should use "erased" rather than > "unlocked". > > For both this function and intel_dimm_security_unlock() in patch 04/12, > could the driver do a loop of clflushopts on one CPU via > clflush_cache_range() rather than run wbinvd on all CPUs? The loop should work, but wbinvd is going to be less overall impact to the performance for really huge ranges. Also, unlock should happen only once and during NVDIMM initialization. So wbinvd should be ok. BTW thanks for looking over the patches. > > --- > Robert Elliott, HPE Persistent Memory > > > > _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm