[PATCH v3] remoteproc: imx_dsp_rproc: Add support for DSP-specific features

Mathieu Poirier mathieu.poirier at linaro.org
Tue Apr 8 06:46:44 PDT 2025


On Tue, 8 Apr 2025 at 02:47, Iuliana Prodan <iuliana.prodan at nxp.com> wrote:
>
> Hello Mathieu,
>
> On 4/7/2025 7:17 PM, Mathieu Poirier wrote:
> > Good morning,
> >
> > On Thu, Apr 03, 2025 at 01:01:24PM +0300, Iuliana Prodan (OSS) wrote:
> >> From: Iuliana Prodan <iuliana.prodan at nxp.com>
> >>
> >> Some DSP firmware requires a FW_READY signal before proceeding, while
> >> others do not.
> >> Therefore, add support to handle i.MX DSP-specific features.
> >>
> >> Implement handle_rsc callback to handle resource table parsing and to
> >> process DSP-specific resource, to determine if waiting is needed.
> >>
> >> Update imx_dsp_rproc_start() to handle this condition accordingly.
> >>
> >> Signed-off-by: Iuliana Prodan <iuliana.prodan at nxp.com>
> >> ---
> >> Changes in v3:
> >> - Reviews from Mathieu Poirier:
> >>    - Added version and magic number to vendor-specific resource table entry.
> >>    - Updated defines to maintain backward compatibility with a resource table that doesn't have a vendor-specific resource.
> >>      - By default, wait for `fw_ready`, unless specified otherwise.
> >> - Link to v2: https://lore.kernel.org/all/20250318215007.2109726-1-iuliana.prodan@oss.nxp.com
> >>
> >> Changes in v2:
> >> - Reviews from Mathieu Poirier:
> >>    - Use vendor-specific resource table entry.
> >>    - Implement resource handler specific to the i.MX DSP.
> >> - Revise commit message to include recent updates.
> >> - Link to v1: https://lore.kernel.org/all/20250305123923.514386-1-iuliana.prodan@oss.nxp.com/
> >>
> >>   drivers/remoteproc/imx_dsp_rproc.c | 102 ++++++++++++++++++++++++++++-
> >>   1 file changed, 100 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/remoteproc/imx_dsp_rproc.c b/drivers/remoteproc/imx_dsp_rproc.c
> >> index b9bb15970966..80d4470cc731 100644
> >> --- a/drivers/remoteproc/imx_dsp_rproc.c
> >> +++ b/drivers/remoteproc/imx_dsp_rproc.c
> >> @@ -35,9 +35,17 @@ module_param_named(no_mailboxes, no_mailboxes, int, 0644);
> >>   MODULE_PARM_DESC(no_mailboxes,
> >>               "There is no mailbox between cores, so ignore remote proc reply after start, default is 0 (off).");
> >>
> >> +/* Flag indicating that the remote is up and running */
> >>   #define REMOTE_IS_READY                            BIT(0)
> >> +/* Flag indicating that the host should wait for a firmware-ready response */
> >> +#define WAIT_FW_READY                               BIT(1)
> >>   #define REMOTE_READY_WAIT_MAX_RETRIES              500
> >>
> >> +/* This flag is set in the DSP resource table's features field to indicate
> >> + * that the firmware requires the host NOT to wait for a FW_READY response.
> >> + */
> >> +#define FEATURE_DONT_WAIT_FW_READY          BIT(0)
> >> +
> >>   /* att flags */
> >>   /* DSP own area */
> >>   #define ATT_OWN                                    BIT(31)
> >> @@ -72,6 +80,10 @@ MODULE_PARM_DESC(no_mailboxes,
> >>
> >>   #define IMX8ULP_SIP_HIFI_XRDC                      0xc200000e
> >>
> >> +#define FW_RSC_NXP_S_MAGIC                  ((uint32_t)'n' << 24 |  \
> >> +                                             (uint32_t)'x' << 16 |  \
> >> +                                             (uint32_t)'p' << 8 |   \
> >> +                                             (uint32_t)'s')
> >>   /*
> >>    * enum - Predefined Mailbox Messages
> >>    *
> >> @@ -136,6 +148,24 @@ struct imx_dsp_rproc_dcfg {
> >>      int (*reset)(struct imx_dsp_rproc *priv);
> >>   };
> >>
> >> +/**
> >> + * struct fw_rsc_imx_dsp - i.MX DSP specific info
> >> + *
> >> + * @len: length of the resource entry
> >> + * @magic_num: 32-bit magic number
> >> + * @version: version of data structure
> >> + * @features: feature flags supported by the i.MX DSP firmware
> >> + *
> >> + * This represents a DSP-specific resource in the firmware's
> >> + * resource table, providing information on supported features.
> >> + */
> >> +struct fw_rsc_imx_dsp {
> >> +    uint32_t len;
> >> +    uint32_t magic_num;
> >> +    uint32_t version;
> >> +    uint32_t features;
> >> +} __packed;
> >> +
> >>   static const struct imx_rproc_att imx_dsp_rproc_att_imx8qm[] = {
> >>      /* dev addr , sys addr  , size      , flags */
> >>      { 0x596e8000, 0x556e8000, 0x00008000, ATT_OWN },
> >> @@ -300,6 +330,73 @@ static int imx_dsp_rproc_ready(struct rproc *rproc)
> >>      return -ETIMEDOUT;
> >>   }
> >>
> >> +/**
> >> + * imx_dsp_rproc_handle_rsc() - Handle DSP-specific resource table entries
> >> + * @rproc: remote processor instance
> >> + * @rsc_type: resource type identifier
> >> + * @rsc: pointer to the resource entry
> >> + * @offset: offset of the resource entry
> >> + * @avail: available space in the resource table
> >> + *
> >> + * Parse the DSP-specific resource entry and update flags accordingly.
> >> + * If the WAIT_FW_READY feature is set, the host must wait for the firmware
> >> + * to signal readiness before proceeding with execution.
> >> + *
> >> + * Return: RSC_HANDLED if processed successfully, RSC_IGNORED otherwise.
> >> + */
> >> +static int imx_dsp_rproc_handle_rsc(struct rproc *rproc, u32 rsc_type,
> >> +                                void *rsc, int offset, int avail)
> >> +{
> >> +    struct imx_dsp_rproc *priv = rproc->priv;
> >> +    struct fw_rsc_imx_dsp *imx_dsp_rsc = rsc;
> >> +    struct device *dev = rproc->dev.parent;
> >> +    size_t expected_size;
> >> +
> >> +    if (!imx_dsp_rsc) {
> >> +            dev_dbg(dev, "Invalid fw_rsc_imx_dsp.\n");
> >> +            goto ignored;
> >> +    }
> >> +
> >> +    /* Make sure resource isn't truncated */
> >> +    expected_size = imx_dsp_rsc->len + sizeof(imx_dsp_rsc->len);
> > Something seems odd with this check... I don't see how adding
> > imx_dsp_rsc->len with 4 will give us any indication of the expected size.
> The fw_rsc_imx_dsp structure is based on Zephyr and OpenAMP ([1]).
>
> The imx_dsp_rsc->len indicates the available resource size. Adding 4
> bytes (for uint32_t len member) gives the total structure size. If this
> does not match sizeof(struct fw_rsc_imx_dsp), the structure is incomplete.
>

Ok, but why is adding 4 to imx_dsp_rsc->len needed?  Why doesn't
imx_dsp_rsc->len already contain the right size?

The size of struct fw_rsc_imx_dsp is 16 byte.  From your
implementation, it seems like ->len is equal to 12 and 4 needs to be
added to make it 16.  To me ->len should be 16... What am I missing?

> I will also verify with avail and send a v4.
>
> [1]
> https://github.com/OpenAMP/open-amp/blob/main/lib/include/openamp/remoteproc.h#L356
>
> Thanks,
> Iulia
> >   To me
> > two checks are required here:
> >
> > 1) if (sizeof(*rsc) > avail)
> >
> > 2) if (sizeof(*rsc) != imx_dsp_rsc->len)
> >
> > Otherwise I'm good with this new revision.
> >
> > Thanks,
> > Mathieu
> >
> >> +    if (expected_size < sizeof(struct fw_rsc_imx_dsp)) {
> >> +            dev_dbg(dev, "Resource fw_rsc_imx_dsp is truncated.\n");
> >> +            goto ignored;
> >> +    }
> >> +
> >> +    /*
> >> +     * If FW_RSC_NXP_S_MAGIC number is not found then
> >> +     * wait for fw_ready reply (default work flow)
> >> +     */
> >> +    if (imx_dsp_rsc->magic_num != FW_RSC_NXP_S_MAGIC) {
> >> +            dev_dbg(dev, "Invalid resource table magic number.\n");
> >> +            goto ignored;
> >> +    }
> >> +
> >> +    /*
> >> +     * For now, in struct fw_rsc_imx_dsp, version 0,
> >> +     * only FEATURE_DONT_WAIT_FW_READY is valid.
> >> +     *
> >> +     * When adding new features, please upgrade version.
> >> +     */
> >> +    if (imx_dsp_rsc->version > 0) {
> >> +            dev_warn(dev, "Unexpected fw_rsc_imx_dsp version %d.\n",
> >> +                     imx_dsp_rsc->version);
> >> +            goto ignored;
> >> +    }
> >> +
> >> +    if (imx_dsp_rsc->features & FEATURE_DONT_WAIT_FW_READY)
> >> +            priv->flags &= ~WAIT_FW_READY;
> >> +    else
> >> +            priv->flags |= WAIT_FW_READY;
> >> +
> >> +    return RSC_HANDLED;
> >> +
> >> +ignored:
> >> +    priv->flags |= WAIT_FW_READY;
> >> +    return RSC_IGNORED;
> >> +}
> >> +
> >>   /*
> >>    * Start function for rproc_ops
> >>    *
> >> @@ -335,8 +432,8 @@ static int imx_dsp_rproc_start(struct rproc *rproc)
> >>
> >>      if (ret)
> >>              dev_err(dev, "Failed to enable remote core!\n");
> >> -    else
> >> -            ret = imx_dsp_rproc_ready(rproc);
> >> +    else if (priv->flags & WAIT_FW_READY)
> >> +            return imx_dsp_rproc_ready(rproc);
> >>
> >>      return ret;
> >>   }
> >> @@ -936,6 +1033,7 @@ static const struct rproc_ops imx_dsp_rproc_ops = {
> >>      .kick           = imx_dsp_rproc_kick,
> >>      .load           = imx_dsp_rproc_elf_load_segments,
> >>      .parse_fw       = imx_dsp_rproc_parse_fw,
> >> +    .handle_rsc     = imx_dsp_rproc_handle_rsc,
> >>      .find_loaded_rsc_table = rproc_elf_find_loaded_rsc_table,
> >>      .sanity_check   = rproc_elf_sanity_check,
> >>      .get_boot_addr  = rproc_elf_get_boot_addr,
> >> --
> >> 2.25.1
> >>



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