From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758644AbcIHJbY (ORCPT ); Thu, 8 Sep 2016 05:31:24 -0400 Received: from mail-wm0-f41.google.com ([74.125.82.41]:36955 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751979AbcIHJbW (ORCPT ); Thu, 8 Sep 2016 05:31:22 -0400 Date: Thu, 8 Sep 2016 10:33:13 +0100 From: Lee Jones To: Loic Pallardy Cc: bjorn.andersson@linaro.org, ohad@wizery.com, linux-remoteproc@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@stlinux.com Subject: Re: [PATCH v2 13/19] remoteproc: core: Append resource only if spare resource present Message-ID: <20160908093313.GM4921@dell> References: <1472676622-32533-1-git-send-email-loic.pallardy@st.com> <1472676622-32533-14-git-send-email-loic.pallardy@st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1472676622-32533-14-git-send-email-loic.pallardy@st.com> User-Agent: Mutt/1.6.2 (2016-07-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 31 Aug 2016, Loic Pallardy wrote: > This patch renames rproc_add_resource_table_entry in __add_rsc_tbl_entry > to have shorter function name and adds spare resource support. > To guarantee remoteproc won't overwrite firmware data when copying > back modified resource table, __add_rsc_tbl_entry verifies first that > resource table owns a spare resource and uses spare bytes to create > a new resource entry. Spare resource is updated according to changes. > > Signed-off-by: Loic Pallardy > --- > drivers/remoteproc/remoteproc_core.c | 54 ++++++++++++++++++++---------------- > 1 file changed, 30 insertions(+), 24 deletions(-) > > diff --git a/drivers/remoteproc/remoteproc_core.c b/drivers/remoteproc/remoteproc_core.c > index aff1a00..25a429b 100644 > --- a/drivers/remoteproc/remoteproc_core.c > +++ b/drivers/remoteproc/remoteproc_core.c > @@ -1107,39 +1107,34 @@ static int __update_rsc_tbl_entry(struct rproc *rproc, > return !updated; > } > > -static struct resource_table* > -rproc_add_resource_table_entry(struct rproc *rproc, > +static int __add_rsc_tbl_entry(struct rproc *rproc, Once again, I prefer plain English over cryptic abbreviations. Makes things much more difficult for developers who are new to, or are just dipping into RemoteProc code. > struct rproc_request_resource *request, > - struct resource_table *old_table, int *tablesz) > + struct resource_table *table, int tablesz) > { > - struct resource_table *table; > struct fw_rsc_hdr h; > + struct fw_rsc_spare spare; > void *new_rsc_loc; > void *fw_header_loc; > void *start_of_rscs; > int new_rsc_offset; > - int size = *tablesz; > - int i; > + int new_spare_offset; > + int i, spare_index = 0; > > h.type = request->type; > > - new_rsc_offset = size; > + /* check available spare size */ In keeping with the existing comments, please use correct grammar. Capital letters to start and for names etc. Much more professional IMO. > + spare.len = __get_rsc_tbl_spare_size(rproc, table, tablesz, &spare_index); > + if (spare.len < (sizeof(h) + request->size + 4)) /* new offset entry */ Not sure that comment makes the code any clearer? All you're doing here is checking if we have enough space, right? I think the 4 is a 'magic' number. I'd either provide a comment (like I did below), or define it. > + return -EPERM; What does this have to do with permissions? > - /* > - * Allocate another contiguous chunk of memory, large enough to > - * contain the new, expanded resource table. > - * > - * The +4 is for the extra offset[] element in the top level header > - */ > - size += sizeof(struct fw_rsc_hdr) + request->size + 4; > - table = devm_kmemdup(&rproc->dev, old_table, size, GFP_KERNEL); > - if (!table) > - return ERR_PTR(-ENOMEM); > + new_rsc_offset = table->offset[spare_index]; > > /* Shunt table by 4 Bytes to account for the extra offset[] element */ > start_of_rscs = (void *)table + table->offset[0]; > memmove(start_of_rscs + 4, > start_of_rscs, new_rsc_offset - table->offset[0]); > + > + spare.len -= 4; This probably deserves a comment too. /* * The spare area is finite. Since we are increasing the size of the * header and shunting the tables, we need to reduce the size of the * available 'spare' area by the shunt size. */ > new_rsc_offset += 4; > > /* Update existing resource entry's offsets */ > @@ -1153,13 +1148,27 @@ rproc_add_resource_table_entry(struct rproc *rproc, > /* Copy new firmware header into table */ > fw_header_loc = (void *)table + new_rsc_offset; > memcpy(fw_header_loc, &h, sizeof(h)); > + spare.len -= sizeof(h); > > /* Copy new resource entry into table */ > new_rsc_loc = (void *)fw_header_loc + sizeof(h); > memcpy(new_rsc_loc, request->resource, request->size); > + spare.len -= request->size; > > - *tablesz = size; > - return table; > + /* create new rsc spare resource at the end of remaining spare */ Same comment about using nice grammar in comments. > + new_spare_offset = new_rsc_offset + sizeof(h) + request->size; > + h.type = RSC_SPARE; > + > + fw_header_loc = (void *)table + new_spare_offset; > + memcpy(fw_header_loc, &h, sizeof(h)); > + > + new_rsc_loc = (void *)fw_header_loc + sizeof(h); > + memcpy(new_rsc_loc, &spare, sizeof(spare)); > + > + /* update spare offset */ > + table->offset[spare_index] = new_spare_offset; > + > + return 0; > } > > static struct resource_table* > @@ -1203,12 +1212,9 @@ rproc_apply_resource_overrides(struct rproc *rproc, > continue; > > /* Didn't find matching resource entry -- creating a new one. */ > - table = rproc_add_resource_table_entry(rproc, resource, > - table, &size); > - if (IS_ERR(table)) > + updated = __add_rsc_tbl_entry(rproc, resource, table, size); > + if (updated) > goto out; > - > - *orig_table = table; > } > > rproc_dump_resource_table(rproc, table, size); -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog