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 <loic.palla...@st.com>
> ---
> 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
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