[PATCH v2 5/5] remoteproc: k3-dsp: Add support for IPC-only mode for all K3 DSPs
Mathieu Poirier
mathieu.poirier at linaro.org
Mon Aug 2 11:26:43 PDT 2021
On Fri, Jul 23, 2021 at 05:02:48PM -0500, Suman Anna wrote:
> Add support to the K3 DSP remoteproc driver to configure all the C66x
> and C71x cores on J721E SoCs to be either in IPC-only mode or the
> traditional remoteproc mode. The IPC-only mode expects that the remote
> processors are already booted by the bootloader, and only perform the
> minimum steps required to initialize and deinitialize the virtio IPC
> transports. The remoteproc mode allows the kernel remoteproc driver to
> do the regular load and boot and other device management operations for
> a DSP.
>
> The IPC-only mode for a DSP is detected and configured at driver probe
> time by querying the System Firmware for the DSP power and reset state
> and/or status and making sure that the DSP is indeed started by the
> bootloaders, otherwise the device is configured for remoteproc mode.
>
> Support for IPC-only mode is achieved through .attach(), .detach() and
> .get_loaded_rsc_table() callback ops and zeroing out the regular rproc
> ops .prepare(), .unprepare(), .start() and .stop(). The resource table
> follows a design-by-contract approach and is expected to be at the base
> of the DDR firmware region reserved for each remoteproc, it is mostly
> expected to contain only the virtio device and trace resource entries.
>
> NOTE:
> The driver cannot configure a DSP core for remoteproc mode by any
> means without rebooting the kernel if that DSP core has been started
> by a bootloader. This is the current desired behavior and can be
> enhanced in the future if the feature is needed.
>
> Signed-off-by: Suman Anna <s-anna at ti.com>
> ---
> v2: Addressed various review comments from v1
> - Reworked the logic to not use remoteproc detach_on_shutdown and
> local ipc-only state flags
> - Plugged in the required IPC-only ops dynamically with the regular
> remoteproc-mode ops zeroed out
> - Dropped all the unneeded error checks in start, stop, prepare,
> unprepare, attach and detach callbacks
> - Callback function descriptions updated to reflect the mode they
> apply to
> - Dropped unused r_state variable in probe
> - Switched to dev_info for the mode information traces from dev_err
> - Revised the last 2 paras of the patch description
> v1: https://patchwork.kernel.org/project/linux-remoteproc/patch/20210522000309.26134-7-s-anna@ti.com/
>
> drivers/remoteproc/ti_k3_dsp_remoteproc.c | 132 +++++++++++++++++++---
> 1 file changed, 115 insertions(+), 17 deletions(-)
>
Reviewed-by: Mathieu Poirier <mathieu.poirier at linaro.org>
> diff --git a/drivers/remoteproc/ti_k3_dsp_remoteproc.c b/drivers/remoteproc/ti_k3_dsp_remoteproc.c
> index faf60a274e8d..6eaecf02aee5 100644
> --- a/drivers/remoteproc/ti_k3_dsp_remoteproc.c
> +++ b/drivers/remoteproc/ti_k3_dsp_remoteproc.c
> @@ -260,7 +260,8 @@ static int k3_dsp_rproc_request_mbox(struct rproc *rproc)
> * used to release the global reset on C66x DSPs to allow loading into the DSP
> * internal RAMs. The .prepare() ops is invoked by remoteproc core before any
> * firmware loading, and is followed by the .start() ops after loading to
> - * actually let the C66x DSP cores run.
> + * actually let the C66x DSP cores run. This callback is invoked only in
> + * remoteproc mode.
> */
> static int k3_dsp_rproc_prepare(struct rproc *rproc)
> {
> @@ -284,7 +285,7 @@ static int k3_dsp_rproc_prepare(struct rproc *rproc)
> * powering down the C66x DSP cores. The cores themselves are only halted in the
> * .stop() callback through the local reset, and the .unprepare() ops is invoked
> * by the remoteproc core after the remoteproc is stopped to balance the global
> - * reset.
> + * reset. This callback is invoked only in remoteproc mode.
> */
> static int k3_dsp_rproc_unprepare(struct rproc *rproc)
> {
> @@ -305,7 +306,7 @@ static int k3_dsp_rproc_unprepare(struct rproc *rproc)
> *
> * This function will be invoked only after the firmware for this rproc
> * was loaded, parsed successfully, and all of its resource requirements
> - * were met.
> + * were met. This callback is invoked only in remoteproc mode.
> */
> static int k3_dsp_rproc_start(struct rproc *rproc)
> {
> @@ -346,7 +347,7 @@ static int k3_dsp_rproc_start(struct rproc *rproc)
> * Stop the DSP remote processor.
> *
> * This function puts the DSP processor into reset, and finishes processing
> - * of any pending messages.
> + * of any pending messages. This callback is invoked only in remoteproc mode.
> */
> static int k3_dsp_rproc_stop(struct rproc *rproc)
> {
> @@ -359,6 +360,78 @@ static int k3_dsp_rproc_stop(struct rproc *rproc)
> return 0;
> }
>
> +/*
> + * Attach to a running DSP remote processor (IPC-only mode)
> + *
> + * This rproc attach callback only needs to request the mailbox, the remote
> + * processor is already booted, so there is no need to issue any TI-SCI
> + * commands to boot the DSP core. This callback is invoked only in IPC-only
> + * mode.
> + */
> +static int k3_dsp_rproc_attach(struct rproc *rproc)
> +{
> + struct k3_dsp_rproc *kproc = rproc->priv;
> + struct device *dev = kproc->dev;
> + int ret;
> +
> + ret = k3_dsp_rproc_request_mbox(rproc);
> + if (ret)
> + return ret;
> +
> + dev_info(dev, "DSP initialized in IPC-only mode\n");
> + return 0;
> +}
> +
> +/*
> + * Detach from a running DSP remote processor (IPC-only mode)
> + *
> + * This rproc detach callback performs the opposite operation to attach callback
> + * and only needs to release the mailbox, the DSP core is not stopped and will
> + * be left to continue to run its booted firmware. This callback is invoked only
> + * in IPC-only mode.
> + */
> +static int k3_dsp_rproc_detach(struct rproc *rproc)
> +{
> + struct k3_dsp_rproc *kproc = rproc->priv;
> + struct device *dev = kproc->dev;
> +
> + mbox_free_channel(kproc->mbox);
> + dev_info(dev, "DSP deinitialized in IPC-only mode\n");
> + return 0;
> +}
> +
> +/*
> + * This function implements the .get_loaded_rsc_table() callback and is used
> + * to provide the resource table for a booted DSP in IPC-only mode. The K3 DSP
> + * firmwares follow a design-by-contract approach and are expected to have the
> + * resource table at the base of the DDR region reserved for firmware usage.
> + * This provides flexibility for the remote processor to be booted by different
> + * bootloaders that may or may not have the ability to publish the resource table
> + * address and size through a DT property. This callback is invoked only in
> + * IPC-only mode.
> + */
> +static struct resource_table *k3_dsp_get_loaded_rsc_table(struct rproc *rproc,
> + size_t *rsc_table_sz)
> +{
> + struct k3_dsp_rproc *kproc = rproc->priv;
> + struct device *dev = kproc->dev;
> +
> + if (!kproc->rmem[0].cpu_addr) {
> + dev_err(dev, "memory-region #1 does not exist, loaded rsc table can't be found");
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + /*
> + * NOTE: The resource table size is currently hard-coded to a maximum
> + * of 256 bytes. The most common resource table usage for K3 firmwares
> + * is to only have the vdev resource entry and an optional trace entry.
> + * The exact size could be computed based on resource table address, but
> + * the hard-coded value suffices to support the IPC-only mode.
> + */
> + *rsc_table_sz = 256;
> + return (struct resource_table *)kproc->rmem[0].cpu_addr;
> +}
> +
> /*
> * Custom function to translate a DSP device address (internal RAMs only) to a
> * kernel virtual address. The DSPs can access their RAMs at either an internal
> @@ -605,6 +678,7 @@ static int k3_dsp_rproc_probe(struct platform_device *pdev)
> struct k3_dsp_rproc *kproc;
> struct rproc *rproc;
> const char *fw_name;
> + bool p_state = false;
> int ret = 0;
> int ret1;
>
> @@ -683,19 +757,43 @@ static int k3_dsp_rproc_probe(struct platform_device *pdev)
> goto release_tsp;
> }
>
> - /*
> - * ensure the DSP local reset is asserted to ensure the DSP doesn't
> - * execute bogus code in .prepare() when the module reset is released.
> - */
> - if (data->uses_lreset) {
> - ret = reset_control_status(kproc->reset);
> - if (ret < 0) {
> - dev_err(dev, "failed to get reset status, status = %d\n",
> - ret);
> - goto release_mem;
> - } else if (ret == 0) {
> - dev_warn(dev, "local reset is deasserted for device\n");
> - k3_dsp_rproc_reset(kproc);
> + ret = kproc->ti_sci->ops.dev_ops.is_on(kproc->ti_sci, kproc->ti_sci_id,
> + NULL, &p_state);
> + if (ret) {
> + dev_err(dev, "failed to get initial state, mode cannot be determined, ret = %d\n",
> + ret);
> + goto release_mem;
> + }
> +
> + /* configure J721E devices for either remoteproc or IPC-only mode */
> + if (p_state) {
> + dev_info(dev, "configured DSP for IPC-only mode\n");
> + rproc->state = RPROC_DETACHED;
> + /* override rproc ops with only required IPC-only mode ops */
> + rproc->ops->prepare = NULL;
> + rproc->ops->unprepare = NULL;
> + rproc->ops->start = NULL;
> + rproc->ops->stop = NULL;
> + rproc->ops->attach = k3_dsp_rproc_attach;
> + rproc->ops->detach = k3_dsp_rproc_detach;
> + rproc->ops->get_loaded_rsc_table = k3_dsp_get_loaded_rsc_table;
> + } else {
> + dev_info(dev, "configured DSP for remoteproc mode\n");
> + /*
> + * ensure the DSP local reset is asserted to ensure the DSP
> + * doesn't execute bogus code in .prepare() when the module
> + * reset is released.
> + */
> + if (data->uses_lreset) {
> + ret = reset_control_status(kproc->reset);
> + if (ret < 0) {
> + dev_err(dev, "failed to get reset status, status = %d\n",
> + ret);
> + goto release_mem;
> + } else if (ret == 0) {
> + dev_warn(dev, "local reset is deasserted for device\n");
> + k3_dsp_rproc_reset(kproc);
> + }
> }
> }
>
> --
> 2.32.0
>
More information about the linux-arm-kernel
mailing list