Re: [PATCH] soc: qcom: cmd-db: Make endian-agnostic

[Lina Iyer]

On Thu, Apr 12 2018 at 16:41 -0600, Stephen Boyd wrote:
> This driver deals with memory that is stored in little-endian format.
> Update the structures with the proper little-endian types and then
> do the proper conversions when reading the fields. Note that we compare
> the ids with a memcmp() because we already pad out the string 'id' field
> to exactly 8 bytes with the strncpy() onto the stack.
>
> Cc: Mahesh Sivasubramanian <msivasub@xxxxxxxxxxxxxx>
> Cc: Lina Iyer <ilina@xxxxxxxxxxxxxx>
> Cc: Bjorn Andersson <bjorn.andersson@xxxxxxxxxx>
> Cc: Evan Green <evgreen@xxxxxxxxxxxx>
> Signed-off-by: Stephen Boyd <swboyd@xxxxxxxxxxxx>
> ---
>
> Changes from inline patch:
> * Fixed magic
> * Made function for memcmp()
> *
>
> drivers/soc/qcom/cmd-db.c | 116 +++++++++++++++++++++-----------------
> 1 file changed, 65 insertions(+), 51 deletions(-)
>
> @@ -99,8 +90,34 @@ struct cmd_db_header {
>  * h/w accelerator and request a resource state.
>  */
>
> +static const char CMD_DB_MAGIC[] = { 0xdb, 0x30, 0x03, 0x0c };
> +
This works now.

> +static bool cmd_db_magic_matches(struct cmd_db_header *header)
> +{
> +	__le32 *magic = &header->magic_num;
> +
> +	return memcmp(magic, CMD_DB_MAGIC, sizeof(CMD_DB_MAGIC)) == 0;
> +}
> +
> static struct cmd_db_header *cmd_db_header;
Could  you move this up, along with other declarations?
> +
> +static inline void *rsc_to_entry_header(struct rsc_hdr *hdr)
> +{
> +	u16 offset = le16_to_cpu(hdr->header_offset);
> +
> +	return cmd_db_header->data + offset;

I noticed that the data was incorrect, with the above and I did it to
read the correct data.

return ((void*)cmd_db_header + sizeof(*cmd_db_header) + offset);
> +}
> +
> +static inline void *
> +rsc_offset(struct rsc_hdr *hdr, struct entry_header *ent)
> +{
> +	u16 offset = le16_to_cpu(hdr->header_offset);
> +	u16 loffset = le16_to_cpu(ent->offset);
> +
> +	return cmd_db_header->data + offset + loffset;
As well here -
return ((void*)cmd_db_header + sizeof(*cmd_db_header) + offset +
loffset);
> +}
> +

Thanks,
Lina